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Strangled

Strangled

Asphyxia or asphyxiation is a condition of severely deficient supply of oxygen to the body. In the absence of remedial action it will very rapidly lead to unconsciousness and death. Asphyxia is the same as suffocation. It comes from the Greek roots a-, "without" and sphuxis, "pulse, heartbeat". Anoxia means the pathological state in which tissues do not get (enough of) oxygen. Asphyxia in humans is a medical emergency. Prolonged asphyxia can result in brain damage even when it does not cause death.

Causes

Causes of asphyxia can include:
- Physical obstruction of the passage of air to or from the lungs:
  - Crushing or constriction of the chest or abdomen
  - Choking
  - Drowning
  - Strangulation, or external constriction of the neck or throat, e.g. by a rope (as in hanging), hands, or a constrictor snake
  - Reduction of the airways due to anaphylaxis or asthma
  - Inhalation of vomit
  - Positional asphyxia
  - The extremely dangerous and frequently deadly practice of erotic asphyxiation, also called "breath control play"
- Breathing in low oxygen environments, for example:
  - the filling of cryogenic vessels with liquified, oxygen-free gases such as nitrogen in an enclosed space
  - workers climbing down into a fermentation vat in a brewery, not realising the vessel has filled with carbon dioxide gas
  - workers climbing down into the holds of ships that contain heavier than air, oxygen-free gases
  - the misuse or failure of diving rebreathers where the breathing gas contains insufficient oxygen
  - breathing a hypoxic breathing gas mixture while diving in shallow water where the partial pressure of oxygen is too low to support consciousness. A hypoxic "bottom gas" is designed only to be breathed at depth.
- Contact with a pulmonary agent or cyanogenic compound
- A seizure which stops breathing activity
- Sleep apnea
- [http://en.wikipedia.org/wiki/Drug_overdose Drug overdose] Problems during childbirth can lead to the newborn experiencing asphyxia (asphyxia neonatorum).

Use in suicide and execution

Recently, asphyxia by carbon monoxide has become a popular suicide method, especially in Japan where suicide pacts involving several individuals are more common. [http://news.bbc.co.uk/2/hi/asia-pacific/3735372.stm] During the period of the Ottoman Empire, strangling with silk rope was a form of capital punishment specified for members of the royal family, who by Ottoman rule could not have their blood spilled.

See also


- Hypoxia (medical)
- Oxygen depletion (aquatic ecology)
- Fan death Category:medical emergencies Category:Diving medicine ja:酸素欠乏症

Oxygen

Oxygen is a chemical element in the periodic table. It has the symbol O and atomic number 8. The element is very common, found not only on Earth but throughout the universe, usually covalently bonded with other elements. Unbound oxygen (usually called molecular oxygen, O2, a diatomic molecule) first appeared on Earth during the Paleoproterozoic era (between 2500 million years ago and 1600 million years ago) and as a product of the metabolic action of early anaerobes (archaea and bacteria). The presence of free oxygen drove most of the organisms then living to extinction. The atmospheric abundance of free oxygen in later geological epochs and up to the present has been largely driven by photosynthetic organisms, roughly three quarters by phytoplankton and algae in the oceans and one quarter from terrestrial plants.

Characteristics

At standard temperature and pressure, oxygen is mostly found as a gas consisting of a diatomic molecule with the chemical formula O2. O2 has two energetic forms:
- The low-energy predominant single-bonded diradical triplet oxygen. This native diradical quality of oxygen contributes to its destructive chemical nature. This form is stabilized by the degeneracy effect.
- The high-energy double-bonded molecule singlet oxygen. Oxygen is a major component of air, produced by plants during photosynthesis, and is necessary for aerobic respiration in animals. The word oxygen derives from two words in Greek, οξυς (oxys) (acid, sharp) and γεινομαι (geinomai) (engender). The name "oxygen" was chosen because, at the time it was discovered in the late 18th century, it was believed that all acids contained oxygen. The definition of acid has since been revised to not require oxygen in the molecular structure. Liquid O2 and solid O2 have a light blue color and both are highly paramagnetic. Liquid O2 is usually obtained by the fractional distillation of liquid air. Liquid and solid O3 (ozone) have a deeper color of blue. A recently discovered allotrope of oxygen, tetraoxygen (O4), is a deep red solid that is created by pressurizing O2 to the order of 20 GPa. Its properties are being studied for use in rocket fuels and similar applications, as it is a much more powerful oxidizer than either O2 or O3.

Applications

Liquid oxygen finds use as an oxidizer in rocket propulsion. Oxygen is essential to respiration, so oxygen supplementation has found use in medicine (as oxygen therapy). People who climb mountains or fly in airplanes sometimes have supplemental oxygen supplies (as air). Oxygen is used in welding (such as the oxyacetylene torch), and in the making of steel and methanol. Oxygen presents two absorption bands centered in the wavelengths 687 and 760 nanometers. Some scientists have proposed to use the measurement of the radiance coming from vegetation canopies in those oxygen bands to characterize plant health status from a satellite platform. This is because in those bands, it is possible to discriminate the vegetation's reflectance from the vegetation's fluorescence, which is much weaker. The measurement presents several technical difficulties due to the low signal to noise ratio and due to the vegetation's architecture, but it has been proposed as possibility to monitor the carbon cycle from satellite, thus in a global scale. Oxygen, as a mild euphoric, has a history of recreational use that extends into modern times. Oxygen bars can be seen at parties to this day. In the 19th century, oxygen was often mixed with nitrous oxide to promote an analgesic effect; indeed, such a mixture (Entonox) is commonly used in medicine today.

History

Oxygen was first discovered by Michał Sędziwój, Polish alchemist and philosopher in late 16th century. Sędziwój assumed the existence of oxygen by warming nitre (saltpeter). He thought of the gas given off as "the elixir of life". Oxygen was again discovered by the Swedish pharmacist Carl Wilhelm Scheele sometime before 1773, but the discovery was not published until after the independent discovery by Joseph Priestley on August 1, 1774, who called the gas dephlogisticated air (see phlogiston theory). Priestley published his discoveries in 1775 and Scheele in 1777; consequently Priestley is usually given the credit. It was named by Antoine Laurent Lavoisier after Priestley's publication in 1775.

Occurrence

Oxygen is the second most common component of the earth's atmosphere (20.947% by volume).

Compounds

Due to its electronegativity, oxygen forms chemical bonds with almost all other elements (which is the origin of the original definition of oxidation). The only elements to escape the possibility of oxidation are a few of the noble gases. The most famous of these oxides is dihydrogen monoxide, or water (H2O). Other well known examples include compounds of carbon and oxygen, such as carbon dioxide (CO2), alcohols (R-OH), aldehydes, (R-CHO), and carboxylic acids (R-COOH). Oxygenated radicals such as chlorates (ClO3−), perchlorates (ClO4−), chromates (CrO42−), dichromates (Cr2O72−), permanganates (MnO4−), and nitrates (NO3−) are strong oxidizing agents in and of themselves. Many metals such as iron bond with oxygen atoms, iron (III) oxide (Fe2O3). Ozone (O3) is formed by electrostatic discharge in the presence of molecular oxygen. A double oxygen molecule (O2)2 is known and is found as a minor component of liquid oxygen. Epoxides are ethers in which the oxygen atom is part of a ring of three atoms.

Isotopes

Oxygen has fifteen known isotopes with atomic masses ranging from 12 to 26. Three of them are stable and twelve are radioactive. The radioisotopes all have half lives of less than three minutes. The stable isotopes have mass numbers of 16, 17 and 18, of which oxygen-16 is the most common (over 99%).

Precautions

Oxygen can be toxic at elevated partial pressures (i.e. high relative concentrations). This is important in some forms of scuba diving, such as with a rebreather. Certain derivatives of oxygen, such as ozone (O3), singlet oxygen, hydrogen peroxide, hydroxyl radicals and superoxide, are also highly toxic. The body has developed mechanisms to protect against these toxic species. For instance, the naturally-occurring glutathione can act as an antioxidant, as can bilirubin which is normally a breakdown product of hemoglobin. Highly concentrated sources of oxygen promote rapid combustion and therefore are fire and explosion hazards in the presence of fuels. This is true as well of compounds of oxygen such as chlorates, perchlorates, dichromates, etc. Compounds with a high oxidative potential can often cause chemical burns. The fire that killed the Apollo 1 crew on a test launchpad spread so rapidly because the pure oxygen atmosphere was at normal atmospheric pressure instead of the one third pressure that would be used during an actual launch. (See partial pressure.) Oxygen derivatives are prone to form free radicals, especially in metabolic processes. Because they can cause severe damage to cells and their DNA, they are thought to be related to cancer and aging.

See also


- Winkler test for dissolved oxygen for instructions on how to determine the amount of oxygen dissolved in fresh water.
- Combustion
- Oxidation
- Oxygen Catastrophe in geology
- The role of oxygen as a diving breathing gas
- Oxygen depletion aquatic ecology
- Ozone layer

References


- [http://periodic.lanl.gov/elements/8.html Los Alamos National Laboratory – Oxygen]
- [http://physics.nist.gov/cgi-bin/AtData/main_asd Nist atomic spectra database]
- [http://chartofthenuclides.com/default.html Nuclides and Isotopes Fourteenth Edition]: Chart of the Nuclides, General Electric Company, 1989

External links


- [http://www.priestleysociety.net Priestley Society, Dedicated to Joseph Priestley the man who discovered oxygen]
- [http://www.best-home-remedies.com/minerals/oxygen.htm Oxygen - Benefits, Deficiency Symptoms And Food Sources]
- [http://www.josephpriestley.info Joseph Priestley Information Website, about the man who discovered oxygen]
- [http://periodic.lanl.gov/elements/8.html Los Alamos National Laboratory – Oxygen]
- [http://www.webelements.com/webelements/elements/text/O/index.html WebElements.com – Oxygen]
- [http://education.jlab.org/itselemental/ele008.html It's Elemental – Oxygen]
- [http://members.tripod.com/tjaartdb0/html/oxygen_toxicity.html Oxygen Toxicity]
- [http://www.uigi.com/oxygen.html Oxygen (O2) Properties, Uses, Applications]
- [http://www.compchemwiki.org/index.php?title=Oxygen Computational Chemistry Wiki]
- [http://koti.mbnet.fi/antitz/dime/en Tests with liquid oxygen :-)] Category:Nonmetals Category:Chalcogens als:Sauerstoff ko:산소 ms:Oksigen ja:酸素 simple:Oxygen th:ออกซิเจน

Unconsciousness

Unconsciousness, more appropriately referred to as loss of consciousness or lack of consciousness, is a dramatic alteration of mental state that involves complete or near-complete lack of responsiveness to people and other environmental stimuli. Being in a comatose state or coma is an illustration of unconsciousness. Fainting due to a drop in blood pressure and a decrese of the oxygen supply to the brain is an illustration of a temporary loss of consciousness. Loss of consciousness must not be confused with altered states of consciousness, such as delirium (when the person is confused and only partially responsive to the environment), normal sleep, hypnosis, and other altered states in which the person responds to stimuli. Loss of consciousness must not be confused with the notion of the psychoanalytic unconscious or cognitive processes (e.g., implicit cognition) that take place outside of awareness. Loss of consciousness may occur as the result of traumatic brain injury, brain hypoxia (e.g., due to a brain infarction or cardiac arrest), severe poisoning with drugs that depress the activity of the central nervous system (e.g., alcohol and other hypnotic or sedative drugs), and other causes.

Law and medicine

In jurisprudence, unconsciousness may entitle the criminal defendant to the defense of automatism, an excusing condition which allows a defendant to argue that they should not be held criminally liable for what would otherwise have been actions or omissions which broke the law. Courts rarely consider "falling asleep" (especially while driving or during surgery) to be an acceptable defense because natural sleep rarely overcomes an ordinary person without warning; however incidents related to epileptic seizures, neurological dysfunctions and sleepwalking may be considered acceptable excusing conditions because the loss of control may not be foreseeable. On the other hand, someone who is less conscious cannot give informed consent to anything. This is relevant in the case of sexual behavior (not allowed with such a person), and also in the case of a patient, with regard to starting or stopping a treatment, and euthanasia.

See also


- coma
- traumatic brain injury
- consciousness
- sleep
- hypnosis
- Do Not Resuscitate
- Living will Category:Consciousness studies

Medical emergency

A medical emergency is an injury or illness that poses an immediate threat to a person's health or life which requires help from a doctor or hospital. The doctor's specialization of emergency medicine includes techniques for effective handling of medical emergencies and resuscitation of patients.

Response

The proper way to handle a medical emergency is to activate emergency medical services by calling for help using a local emergency telephone number, such as 911 in Canada or the United States, 999 in the UK, 112 in most of continental Europe, 119 in South Korea, 000 in Australia and 111 in New Zealand. Operators will generally require the caller's name and location and some information on person that is being called about (level of consciousness, injuries, name if known, chronic medical illnesses if known). Those trained to perform first aid can act within their expertise, while those who are not do best to remain calm and stay with the person. Crowding is generally unhelpful, unless the presence of others is needed. Evacuating the victim requires special skills, and is generally best left to professionals, unless there is no other alternative (as in wilderness first aid). Self-transport should be to the nearest emergency room. In the absence of breathing or a palpable heartbeat, artificial respiration and cardiopulmonary resuscitation (CPR) may be immediately required to save the victim's life. Emergency medical technicians, Outdoor Emergency Care technicians or paramedics can use airway management techniques to help a person who is not breathing.

Clinical response

Within hospital settings, an adequate staff is generally present to deal with the average emergency situation. Emergency medicine physicians have training to deal with most medical emergencies, and maintain CPR and ACLS certifications. In disasters or complex emergencies, most hospitals have protocols to summon on-site and off-site staff rapidly. Both emergency room and inpatient medical emergencies follow the basic protocol of Advanced Cardiac Life Support. Irrespective of the nature of the emergency, adequate blood pressure and oxygenation are required before the cause of the emergency can be eliminated. Possible exceptions include the clamping of arteries in severe hemorrhage.

See also


- List of medical emergencies Category:Emergency medicine
-

Constriction

Constriction is a method used by various snake species to kill their prey. The snake initially bites its prey and holds on, pulling the prey into its coils or, in the case of very large prey, pulling itself onto the prey. The snake will then wrap one or two coils around the prey, typically the prey's chest. Contrary to myth, the snake does not crush the prey, or even break its bones, but instead squeezes, tightening its grip every time the prey exhales and holding firm, until the prey can no longer draw in air. Another common misconception is that the snake asphyxiates its prey when, in fact, the pressure applied to the prey is so great that it causes the heart to stop beating. The snake will then begin to feed. The entire process is surprisingly rapid, with prey often succumbing as quickly as a minute after being struck. Certain groups of snakes have sterotyped patterns of constriction, including the number of coils they use and the orientation of the coils. Also, there is controversy about how much role restriction of circulation plays in subduing prey.



Choking

Choking is the obstruction of the flow of air into a person's lungs by a foreign object, commonly food. Choking can become a medical emergency, as choking prevents breathing and will thus starve the brain and other organs of oxygen. If the casualty can still cough effectively they will probably be able to cough up the offending object. The first aid at this point is to stand by and encourage coughing. If the casualty is completely silent and cannot cough or make noise, this indicates a entirely blocked airway. If they are still conscious they should be given up to five back blows. If that does not work administer up to five abdominal thrusts. In order to give the back blowes: :"Stand to the side and slightly behind the victim. Support the chest with one hand and lean the victim well forwards so that when the obstructing object is dislodged it comes out of the mouth rather than goes further down the airway. Give up to five sharp blows between the shoulder blades with the heel of your other hand." [http://www.resus.org.uk/pages/bls.pdf]. If the victim lose consciousness, call for help using the emergency telephone number and commence CPR immediately. Abdominal thrusts, previously known as the Heimlich maneuver, carry the risk of rib fractures and serious internal injuries, are recommended for conscious patients if five back slaps have been unsuccessful. Artificial respiration may be required after the airway is cleared and they are not breathing. Because of the risk of serious organ damage, anybody receiving abdominal thrusts needs medical assessment afterwoods. Inspection of the pharynx and larynx with a laryngoscope, and removal of the object under direct vision is the advanced medical procedure. Paramedics carry laryngoscopes in the field.

References

# UK Resuscitation Council Basic Life Support [http://www.resus.org.uk/pages/bls.pdf] based on the ILCOR 2005 Guidelines

See also


- Chokehold
- Breath category:medical emergencies category:first aid

Neck

The neck is the part of the body on many limbed vertebrates that distinguishes the head from the torso or trunk.

Anatomy of the human neck

Bony anatomy: The cervical spine

The cervical portion of the human spine comprises seven bony segments, typically referred to as C-1 to C-7, with cartilaginous disks between each vertebral body. From top to bottom the cervical spine is gently curved in convex-forward fashion.

Soft tissue anatomy

torso and neck.]] torso and neck.]] In the middle line below the chin can be felt the body of the hyoid bone, just below which is the prominence of the thyroid cartilage called "Adam's apple," better marked in men than in women. Still lower the cricoid cartilage is easily felt, while between this and the suprasternal notch the trachea and isthmus of the thyroid gland may be made out. At the side the outline of the sterno-mastoid muscle is the most striking mark; it divides the anterior triangle of the neck from the posterior. The upper part of the former contains the submaxillary gland, which lies just below the posterior half of the body of the jaw. The line of the common and the external carotid arteries may be marked by joining the sterno-clavicular articulation to the angle of the jaw. The eleventh or spinal accessory nerve corresponds to a line drawn from a point midway between the angle of the jaw and the mastoid process to the middle of the posterior border of the sterno-mastoid muscle and thence across the posterior triangle to the deep surface of the trapezius. The external jugular vein can usually be seen through the skin; it runs in a line drawn from the angle of the jaw to the middle of the clavicle, and close to it are some small lymphatic glands. The anterior jugular vein is smaller, and runs down about half an inch from the middle line of the neck. The clavicle or collar-bone forms the lower limit of the neck, and laterally the outward slope of the neck to the shoulder is caused by the trapezius muscle.

See also


- Anatomy
- Hanging
- Torticollis simple:Neck

Throat

:For the sailing term, see throat halyard. In anatomy, the throat is the part of the neck anterior to the vertebral column. It consists of the pharynx and larynx. The throat contains various blood vessels, various pharyngeal muscles, the trachea (windpipe) and the esophagus. The hyoid bone is the only bone located in the throat of mammals. Category:head and neck category:Respiratory system

Rope

: Rope is also the title of a movie by Alfred Hitchcock : Rope is also the name of an open-source firewall programming language Rope A rope is a length of fibers, twisted or braided together to improve strength, for pulling and connecting. It has tensile strength but is too flexible to provide compressive strength (i.e., it can be used for pulling, not pushing). Common materials for rope include manila, hemp, hair, nylon, and steel. Sometimes woven straps or chains are used where rope could be used, especially in securing loads to vehicles. Other fibrous plant materials sometimes used include cotton, linen, coconut-husk fiber (coir), jute, and sisal. Other synthetic fibers in use include various forms of polypropylene, polyethylene (e.g. Spectra ® a high modulus polyethylene), aramid (e.g. Kevlar ®), and polyester (e.g. Dacron ®). Some ropes are constructed of mixtures of several fibers or use co-polymer (mixed) fibers. Rope has been an essential tool since prehistoric times. Today, steel wire rope has largely supplanted fiber rope in heavy construction and industrial applications because of higher tensile strength. Fiber rope is still used extensively in light industry and in activities like sailing and climbing. In order to fasten ropes, a large number of knots are used. Some rope material, like hemp, is stronger when wet with water. A pulley is used to convert the pulling force to another direction, and multiple pulleys may be used to increase the mechanical advantage, allowing the pulling or lifting of heavy loads with limited force and strength of rope. Winches and capstans are machines designed to pull ropes.

Styles of rope construction

Twisted ropes and hawsers

Twisted rope, also called laid rope, is historically the prevalent form of rope, at least in modern western history. Most twisted rope consists of three strands and is normally right-laid, or given a right handed twist. Large heavy duty ropes are sometimes called hawsers. Twisted hawsers were often made of 4 strands of right laid rope, laid left, or given a left handed twist, this was sometimes called cable-laid. More strands are sometimes used. Twisted ropes are built up in three steps. First, fibers are gathered and spun to form yarns. A number of these yarns are then twisted together to form strands. The strands are then twisted together to form the rope. The twist of the yarn is opposite to that of the strand, and that in turn is opposite to that of the rope. This counter-twisting helps keep the rope together. Any rope of this type must be bound at its end by some means to prevent untwisting. Twisted ropes have a preferred direction for coiling. Normal right laid rope should be coiled with the sun, or clockwise, to prevent kinking. Coiling this way imparts a twist to the rope. Braided ropes (and objects like garden hoses, fiber optic or coaxial cables, etc.) that have no lay, or inherent twist, will uncoil better if coiled into figure-8 coils, where the twist reverses regularly and essentially cancels out. Before modern rope making machines were invented, these ropes were constructed in a rope walk. This was a very long building where strands the full length of the rope were spread out and then laid up or twisted together to form the rope. The cable length was thus set by the length of the available rope walk. (See also the unit of length called cable length.)

Braided ropes for sailing, climbing, and safety

"Laid" or twisted ropes tend to untwist under load causing the load to spin if not otherwise supported. Therefore, ropes used for sailing, climbing, and rescue applications are usually braided to avoid this problem. Braided ropes can be divided into two primary categories: dynamic ropes and static ropes. Static ropes have low stretch properties. The typically stretch less than 6% under normal loading conditions. They are used for controlling sails and for rappelling, especially in caving because the rope itself is climbed, rather than the rock. They are also used for carrying or hauling equipment and attaching pieces of equipment together. Dynamic ropes are made to stretch as much as 50% of their unloaded length, which is crucial for limiting the maximum force experienced by a climber that falls when using one (and also the maximum force experienced by any piece of gear securing the climber to the rock or ice). The main ropes (called lead ropes when the climber is leading) that a climber uses are dynamic. Braided ropes are generally made from nylon, polyester or polypropylene and have kern mantle construction. Nylon is preferred for durability and good resistance to ultraviolet light. Polyester is about 90% as strong as nylon but has better UV resistance and less change in length when wet. Polypropylene is preferred for low cost and light weight (it floats on water). Kernmantle ropes have a core (kern) of long fibers in the center, with a braided outer sheath (mantle) of woven coloured fibers. The kern provides most of the strength, the mantle protects the kern and determines the handling properties of the rope (how easy it is to hold, to tie knots in, and so on). In dynamic ropes, the core fibers are usually twisted, and chopped into shorter lengths which makes the rope more stretchy. Static ropes are made with untwisted core fibers and tighter braid, which causes them to be stiffer in addition to limiting the stretch. Braided ropes without a core have a much lower strength to weight ratio, but are cheaper than kernmantle ropes. Thus, they are used for low cost applications and where strength is less important, such as general utility applications in the home. Braided ropes are made in a wide range of diameters, from 1 mm to over 13 mm for rescue applications.

How to handle rope

woven Rope made from hemp or nylon should be stored in a cool dry place. It should be coiled and not twisted. If rope is found to be fraying you can melt some wax onto the end or in the case of nylon rope just melt the end so it fuses together. For fibre rope, fixing frayed ends can be more difficult. A strong twine should be used to lash the frayed end together to produce a whipped rope; this will help the end from coming apart again and make tying knots easier. If a load-bearing rope gets a sharp or sudden jolt or shows signs of deteriorating the rope should be replaced immediately and should be discarded or only used for non-load-bearing tasks.

Punitive uses


- Ropes are also used to tie down punishees, especially for severe corporal punishment
- Furthermore ropes can be used (as so-called pervertibles) as a whipping device, of widely different impact depending on length, weight and whether the target zone is bare; working in knots or hard objects gives at a fiercer bite. One realizes its potential sting when considering the dreaded cat o' nine tails was usually made of rope, as were the milder knittles. Thus aboard ships, a rope's end was frequently applied as an implement for the lightest on the spot discipline of boy and adult sailors, but considered merely a tangible warning as even a few informal strokes of the bosun's cane for somewhat worse offenders were not deemed worthy of a formal record.
- In the Royal Navy, the terms Bimmy, Teazer, Togey and Sennet whip were all usual for a similar implement for summary discipline used on boys' backsides: a rope of about 18 inches long was dipped in hot tar to make it heavier and brittle, usually with a knot on the striking end (the term 'bull's eye was used when that hit precisely between the buttocks, so either on crack or family jewels, both far more tender then the fleshy mounds) - naughty boys were ordered to bend over on the spot presenting their posterior to be lashed with it for such futiilties as taking too long to get in or out of the bath tub (then still wet and stark naked); however the terms were equally used for a thin whip made for leather shoe laces pleated to a single end
- The rope is also a metonymical expression, as the noose, for capital punishment by hanging. category: corporal punishments

See also


- Jump rope for rope skipping
- Lashing knot
- Whipped rope
- Ropework

External link


- [http://www.tensiontech.com/ Tension Technology International offers resources on rope fiber characteristics] Category:Cables Category:Climbing equipment Category:Ropework Category:Survival skills Category:Tools ja:ロープ

Hanging

Hanging is a form of execution or a method for suicide. Hanging may involve breaking of the neck (cervical fracture, in the case of a "long-drop"), or one or more of the following (in the case of a "short-drop"):
- Closing the airway
- Closing the carotid arteries
- Closing the jugular veins
- Carotid reflex (which reduces heartbeat when the pressure in the carotid arteries is high) causing cardiac arrest As punishment it has been used throughout history. In England the short drop method was used until the 19th century, when the long-drop was introduced. The short-drop could be a protracted affair and was primarily for the entertainment of the watching public, the struggling of the victim giving rise to such terms as "the hangman's hornpipe".

History

Hanging has been used as punishment throughout history; it is known to have been invented and used by the Persian Empire. The typical sentence involving hanging is that the condemned person "be hanged by the neck until dead". A more elaborate sentence, once used for particularly heinous crimes (e.g., high treason in Britain), was for the person to be "hanged, drawn and quartered" – here the victim was saved from asphyxiation in order to endure the further ordeals. Hanging has historically been the method of execution used for common criminals; in feudal England, for example, peasants were usually hanged for crimes, while the nobility were usually beheaded. Since as a result hanging has become associated with dishonorable execution, the courts in the post-World War II war crimes trials in Germany (the Nuremberg trials) and Japan mandated its use for war criminals rather than execution by firing squad. As a form of judicial execution in England, hanging is thought to date from the Saxon period, circa AD 400. Records of the names of British hangmen begin with Thomas de Warblynton in the 1360s; complete records extend from the 1500s to the last hangmen, Robert Leslie Stewart and Harry Allen, who conducted the last British executions in 1964. Early methods of hanging simply involved a hangman's noose on a rope placed around the victim's neck, with the loose end thrown over or tied to a tree branch; the hangman then drew up the criminal, who slowly strangled. An early refinement had the victim climb a ladder or stand in a cart that the hangman then removed. As the number of executions increased, purpose-built gallows, which usually consisted of two posts joined by a crossbeam, replaced trees. Soon virtually every major town and city in Britain had its own gallows. Although hangmen had introduced the "drop" by the late 1700s, it was initially only a substitute for the ladder or the cart. The first well-known practitioner of "the drop" was William Calcraft, but his successor William Marwood (who was often quoted as saying "Calcraft hanged them, I execute them"), introduced the "long drop". Marwood realised that each person required a different drop, based on the prisoner's weight, which would dislocate the cervical vertebrae resulting in "instantaneous" death. vertebrae A process of sometimes grisly experimentation led to the discovery that an energy of 1260 foot pounds (1710 joules) would have the desired effect, so one could calculate the required drop by dividing 1260 by the weight of the victim: a person weighing 112 pounds (50.8 kg) required a drop of 11'4" (3.43 m). Over time, Marwood refined this basic formula to take account of the prisoner's age, stature, and physical condition, especially after some early mistakes when too great a drop resulted in decapitation. Marwood also experimented with the positioning of the knot, and discovered that placing it under the left ear or under the angle of the left jaw would jerk the head backwards at the end of the drop and instantly sever the spinal cord and dislocate the cervical vertebrae. Prison governors and staff who were required, following the abolition of public executions in 1868, to witness executions at close quarters, welcomed the development of swift and "clean" methods of hanging. As time went by, hanging became more of a science than an art. By the mid-20th century the average time between taking a victim from the cell and death was around fifteen seconds – although on May 8, 1951 Albert Pierrepoint conducted the fastest hanging on record when James Inglis, whom a court had only three weeks earlier convicted and sentenced for the murder of a prostitute, fell through the trap only seven seconds after leaving his cell. Extra-legal primitive forms of hanging persisted well into the 20th Century in the United States in the form of lynchings, where torture and/or mutilation of the corpse often accompanied the hanging. Death is cause by severing the spinal cord between C1 and C2, which stops breathing by effectively stopping the diaphragm from working. Forensic experts can tell if hanging is suicide or homicide, as each leaves a distinctive ligature mark. If the hyoid bone is broken, it usually means the person has been murdered. Also, there have been cases of autoerotic asphyxiation leading to death; recently, kids have died from playing the choking game.

Britain

Until 1808 the law in Britain offered the death penalty for some 200 offenses, including:
- Attempting suicide
- Being in the company of gypsies for one month
- Vagrancy for soldiers and sailors
- "Strong evidence of malice" in children aged 7–14 years old A variety of loopholes in British criminal law, together with judicial leniency, tempered the law's tendency to prescribe hanging for what many would today consider minor offences. First-time offenders could escape a capital sentence for some crimes through the benefit of clergy, and of those criminals actually sentenced to death, many were later pardoned. Only about half the death sentences pronounced at common law in the 18th century were carried out, and by the beginning of the 19th century, growing doubt over the appropriateness of capital punishment led to nearly 90% of British capital sentences being commuted to lesser punishments. Between 1832 and 1834 Parliament abolished the death penalty for:
- Shoplifting goods worth five shillings (£0.25) or less
- Returning from Transportation
- Letter-stealing
- Sacrilege In 1861 The Parliament reduced the number of capital crimes to four:
- Murder
- Treason
- Arson in Royal Dockyards
- Piracy with violence Britain ended public hangings in 1868 and formally abolished the hanging, beheading and quartering of traitors in 1870. In 1965 Parliament passed the 'Murder (Abolition of Death Penalty) Act' abolishing capital punishment for murder. And with the introduction of the Human Rights Act in 1998, the death penalty was officially abolished for all crimes in both civilian and military cases.

Soviet Union

In the Soviet Union, the last persons to be sentenced to death by hanging were Andrey Vlasov and 11 other officers of his army on August 1, 1946.

Iran

1946 One of the hanging execution procedures currently used in Iran does not use a drop, but involves using an automotive telescoping crane to hoist the condemned aloft. This method may have been adapted from yardarm hangings carried out by the Royal Navy. A recent hanging carried out by this method in Iran was that of a 16 year old girl, Ateqeh Rajabi, who was hanged in August 2004 for sexual misdemeanours. The conduct of her case and her actual execution were very controversial internationally.

The United States

In the United States, other forms of capital punishment, such as the electric chair and more recently lethal injection, have largely replaced hanging. At present, only Washington and New Hampshire still retain hanging as an option. Laws changed in 1996 that penalties of death must be executed by injection unless the convict chooses hanging, but none has taken place ever since. In New Hampshire if it found "... to be impractical to carry out the punishment of death ..." by lethal injection, then the condemned will be hanged.[http://www.gencourt.state.nh.us/rsa/html/lxii/630/630-5.htm] In Washington, the default method is lethal injection, though the condemned can choose hanging.[http://www.leg.wa.gov/RCW/index.cfm?section=10.95.180&fuseaction=section] Serial killer and child molester Westley Allan Dodd chose it over injection in 1992. (See the book Driven to Kill.) Charles Campbell was another person hanged in the same State on 27 May 1994. The last person hanged in the United States was Billy Bailey, on January 25 1996 in Delaware, and later the same state abolished this practice.

Singapore

Singapore has an extensive history of hanging, currently employing mandatory execution as punishment for various crimes. The government controlled media of Singapore relinquish attention from anti-death penalty movements which are graphically stirring in the country since the execution of a 25-year old Australian, Nguyen Tuong Van, who was hanged on December 2, 2005 despite pleas from Australian politicians, religious leaders, cultural leaders, diplomats, Amnesty International and numerous other international pressure to allow a stay. Hanging remains the primary form of capital punishment in Singapore. Local laws mandate the death penalty for drug trafficking above certain quantities. Whether recent debate and international pressure resulting from the hanging of Nguyen Tuong Van will lead to changes remains to be seen. Singapore is one of the few countries in which citizens who hold contrary views to the death penalty are liable to criminal charges as well as state sponsored harassment. Evidence of this can be seen in the recent backlash against artistic displays vilifying 'state sponsored murder' as the artists put it, with officials destroying the artworks within hours of the displays opening.

Recent hangings

Nguyen Tuong Van, 2005). [http://direland.typepad.com/direland/2005/07/iran_executes_2.html][http://www.gayrussia.ru/en/detail.php?ID=1596].]] Hanging is commonly the method of executing penalties of death in Commonwealth countries that still have it, e.g., Malaysia and Singapore. A recent case of capital punishment by hanging is that of Dhananjoy Chatterjee, who was convicted of the 1990 murder and rape of a 14 year old girl in Kolkata(Calcutta) in India. Although the Supreme Court of India has suggested that capital punishment be given in the rarest of rare cases, Chatterjee was executed on August 14 2004 in the first execution in West Bengal for eleven years. On February 27 2004 the mastermind of the Sarin gas attack on the Tokyo subway, Shoko Asahara, was found guilty and sentenced to death by hanging. Hanging is the common method of execution in capital punishment cases in Japan, although the punishment is rarely executed. On July 19 2005, two Iranian boys, Mahmoud Asgari and Ayaz Marhoni, were publicly hanged at Edalat (Justice) Square in Mashhad, northeast Iran, on charges of homosexuality and rape. The punishment has been met with international outrage. At the ages of 15 and 17, respectively, they were discovered having sexual relations. They were imprisoned for fourteen months and subjected to 228 lashes each, then executed. According to the ISNA report as translated by OutRage "They admitted having gay sex but claimed in their defense that most young boys had sex with each other and that they were not aware that homosexuality was punishable by death." Subsequent to their execution the government broadcast the allegation that they had raped a 13-year-old boy, a story rejected by MAHA, the voice of the Iranian gay community.[http://direland.typepad.com/direland/2005/07/iran_executes_2.html][http://www.gayrussia.ru/en/detail.php?ID=1596] In Singapore, a 25-year old Australian, Nguyen Tuong Van, was hanged on December 2, 2005 on charges of drug trafficking in 2002. Numerous efforts from both the Australian government, numerous QCs (Queens Counsels) and countless petitions from organisations such as Amnesty International had failed. Opinion in Australia is divided, with people both opposed to and in support of the death penalty. Many Australian people have said that they will boycott Singapore in a backlash from this hanging. Others, in both Singapore and Australia, have accepted the hanging as law.

Grammar

The term "hanging" is the focus of a famous bit of grammatical trivia. Traditionally, the past tense and past participle of the verb "to hang" are "hung" when referring to the abstract idea of hanging things, but "hanged" when referring to an execution or death by hanging.[http://www.webster-dictionary.org/definition/hang][http://trackerpress.com/pdf/Page_60.pdf] For example, consider the following sentence: ::The butcher hanged himself in the freezer where he had hung meat. In the musical My Fair Lady, Professor Higgins (ironically, a linguistic genius) sings in the song "Why Can't the English?": ::By rights she should be taken out and hung ::For the cold-blooded murder of the English tongue For the sake of rhyming, he commits the error, when grammatically he should have correctly said "taken out and hanged". linguistic

Folklore

A common legend holds that if the rope used to hang a person breaks three times, it is a sign of divine intervention and the condemned should be released.

See also


- Capital punishment in the United Kingdom
- Death erection
- Gallows
- Hand of Glory
- Jack Ketch
- Lynching
- Official Table of Drops

External links


- [http://users.bestweb.net/~rg/execution/Protocol%20Hanging.htm 1990 Manual for Hanging in the State of Delaware]. Provides mathematical formulas for determining the proper "drop" height of a condemned criminal.
- [http://members.aol.com/RVSNorton/Lincoln3.html The Hanging of the convicted Lincoln assassination conspirators] Category:Death penalty Category:Human body positions ja:絞首刑

Anaphylaxis

Anaphylaxis is a severe and rapid systemic allergic reaction to a trigger substance, called an allergen. Minute amounts of trigger substances may cause a life-threatening anaphylactic reaction. Anaphylaxis may occur after ingestion, inhalation, skin contact or injection of a trigger substance. The most severe type of anaphylaxis - anaphylactic shock - will usually result in death if untreated. The word is from New Latin (derived from Greek ανα/ana, meaning against, from another, or not belonging to) + phylum (from φιλον/phylon, meaning tribe or race) — in taxonomy, a primary division of one of the kingdoms. A rough but reasonable layperson's translation might be "from another species" — reflecting the fact that anaphylaxis/anaphylactic shock is caused by the body's reaction to contact with, or absorption of, (by ingestion, inhalation, etc.) material from another species of plant, animal, or fungal life. (While biological taxonomy is a complex and controversial topic — the mechanisms and effects of viruses, bacteria, and other micro-organisms on macro-organisms (particularly humans and animals) are not within the scope of anaphylaxis.)

Immediate action

Anaphylactic shock is a life-threatening medical emergency because of rapid constriction of the airway, often within minutes of onset. Calling for help immediately can save precious minutes. First aid for anaphylactic shock consists of obtaining advanced medical care at once; rescue breathing (a skill which is part of CPR) is likely to be ineffective but should be attempted if the victim stops breathing. The patient may have been diagnosed with anaphylaxis in the past, and could be carrying an EpiPen (or similar device) that could be available for immediate administration of epinephrine (adrenaline) by a layperson. Repetitive administration is only dangerous when done in rapid succession. Pulse rates in double-administration cases have been known to cause tachycardia (rapid heartbeat) and occasionally ventricular tachycardia with heart rates up to 240 beats per minute. Nevertheless, if epinephrine prevents worsening of the airway constriction, it may still be life-saving.

Symptoms

Symptoms of anaphylaxis are related to the action of immunoglobulin E (IgE) and other anaphylatoxins, which act to release histamine and other mediator substances from mast cells (degranulation). In addition to other effects, histamine induces vasodilation and bronchospasm (constriction of the airways). Symptoms can include the following:
- respiratory distress,
- hypotension (low blood pressure),
- fainting,
- unconsciousness,
- urticaria (hives),
- flushed appearance,
- angioedema (swelling of the face, neck and throat),
- vomiting,
- itching, and
- anxiety, including a sense of impending doom

Causes

Common causative agents in humans include:
- foods (e.g. milk, cheese, nuts, peanuts and other legumes, fish and shellfish, wheat and eggs);
- drugs (e.g. penicillin and other cephalosporins, contrast media, ASA and other NSAIDs such as ibuprofen and diclofenac);
- latex;
- Hymenoptera stings from insects such as bees, wasps, yellow jackets, hornets, and some stinging ants; and
- exercise (see exercise-induced anaphylaxis).
- Perfumes, colognes and fragrances found in air fresheners, soaps, detergents, lotions and many other products are increasingly made from chemicals these days. Some modern fragrances now come from organic synthesis compounds similar to pesticides. In the past most came from natural essential oils. Transfusion of incompatible blood products may lead to extremely similar symptoms, albeit for substantially different biochemical reasons.

Treatment

Paramedic treatment in the field may include injection with epinephrine, administration of oxygen therapy and, if necessary, intubation during transport to advanced medical care. In profuse angioedema, tracheotomy may be required to maintain oxygenation. The clinical treatment of anaphylaxis by a doctor and in the hospital setting aims to treat the cellular hypersensitivity reaction as well as at the symptoms. Antihistamine drugs (which inhibit the effects of histamine at histamine receptors) are given but are usually not sufficient in anaphylaxis, and high doses of intravenous corticosteroids are often required. Hypotension is treated with intravenous fluids and sometimes vasoconstrictor drugs. For bronchospasm, bronchodilator drugs (e.g. salbutamol) are used. In severe cases, immediate treatment with epinephrine can be lifesaving. Supportive care with mechanical ventilation may be required.

See also


- Atopic syndrome
- Hypersensitivity Category:Medical emergencies

Asthma

.]] Asthma is a disease of the human respiratory system in which the airways narrow, often in response to a "trigger" such as exposure to an allergen, cold air, exercise, or emotional stress. This narrowing causes symptoms such as wheezing, shortness of breath, chest tightness, and coughing, which are the hallmarks of asthma. Between episodes, most patients feel fine. The disorder is a chronic inflammatory condition in which the airways develop increased responsiveness to various stimuli, characterized by bronchial hyper-responsiveness, inflammation, increased mucus production, and intermittent airway obstruction. The symptoms of asthma, which can range from mild to life threatening, can usually be controlled with a combination of drugs and lifestyle changes. Public attention in the developed world has recently focused on asthma because of its rapidly increasing prevalence, affecting up to one in four urban children. Susceptibility to asthma can be explained in part by genetic factors, but no clear pattern of inheritance has been found. Asthma is a complex disease that is influenced by multiple genetic, developmental, and environmental factors, which interact to produce the overall condition.

History

The word asthma is derived from the Greek aazein, meaning "sharp breath". The word first appears in Homer's Iliad; Hippocrates was the first to use it in reference to the medical condition. Hippocrates thought that the spasms associated with asthma were more likely to occur in tailors, anglers, and metalworkers. Six centuries later, Galen wrote much about asthma, noting that it was caused by partial or complete bronchial obstruction. Moses Maimonides, an influential medieval rabbi, philosopher, and physician, wrote a treatise on asthma, describing its prevention, diagnosis, and treatment. In the 17th century, Bernardino Ramazzini noted a connection between asthma and organic dust. The use of bronchodilators started in 1901, but it was not until the 1960s that the inflammatory component of asthma was recognized, and anti-inflammatory medications were added to the regimen.

Signs and symptoms

An acute exacerbation of asthma is referred to colloquially as an asthma attack. The clinical hallmarks of an attack are shortness of breath (dyspnea) and wheezing, the latter "often being regarded as the sine qua non". A cough—sometimes producing clear sputum—may also be present. The onset is often sudden; there is a "sense of constriction" in the chest, breathing becomes difficult, and wheezing occurs (typically in both respiratory phases). Signs of an asthmatic episode are wheezing, rapid breathing (tachypnea), prolonged expiration, a rapid heart rate (tachycardia), rhonchous lung sounds (audible through a stethoscope), and over-inflation of the chest. During a serious asthma attack, the accessory muscles of respiration may be used, shown as in-drawing of tissues between the ribs and above the sternum and clavicles, and the presence of a paradoxical pulse (a pulse that is weaker during inhalation and stronger during exhalation). During very severe attacks, an asthma sufferer can turn blue from lack of oxygen, and can experience chest pain or even loss of consciousness. Severe asthma attacks may lead to respiratory arrest and death. Despite the severity of symptoms during an asthmatic episode, between attacks an asthmatic may show few signs of the disease.

Diagnosis

In most cases, a physician can diagnose asthma on the basis of typical findings in a patient's clinical history and examination. Asthma is strongly suspected if a patient suffers from eczema or other allergic conditions—suggesting a general atopic constitution—or has a family history of asthma. While measurement of airway function is possible for adults, most new cases are diagnosed in children who are unable to perform such tests. Diagnosis in children is based on a careful compilation and analysis of the patient's medical history and subsequent improvement with an inhaled bronchodilator medication. In adults, diagnosis can be made with a peak flow meter (which tests airway restriction), looking at both the diurnal variation and any reversibility following inhaled bronchodilator medication. Testing peak flow at rest (or baseline) and after exercise can be helpful, especially in young asthmatics who may experience only exercise-induced asthma. If the diagnosis is in doubt, or if chronic obstructive pulmonary disease is suspected, a more formal lung function testing may be conducted. Once a diagnosis of asthma is made, a patient can use peak flow meter testing to monitor the severity of the disease.

Differential diagnosis

Before diagnosing someone as asthmatic, alternative possibilities should be considered. A physician taking a history should check whether the patient is using any known bronchoconstrictors (substances that cause narrowing of the airways, e.g., certain anti-inflammatory agents or beta-blockers). Only a minority of asthma sufferers have an identifiable allergy trigger. The majority of these triggers can often be identified from the history; for instance, asthmatics with hay fever or pollen allergy will have seasonal symptoms, those with allergies to pets may experience an abatement of symptoms when away from home, and those with occupational asthma may improve during leave from work. Occasionally, allergy tests are warranted and, if positive, may help in identifying avoidable symptom triggers. After pulmonary function has been measured, radiological tests, such as a chest X-ray or CT scan, may be required to exclude the possibility of other lung diseases. In some people, asthma may by triggered by gastroesophageal reflux disease, which can be treated with suitable antacids. Very occasionally, specialized tests after inhalation of methacholine—or even less commonly histamine—may be performed.

Pathophysiology

Bronchoconstriction

histamine react to environmental triggers such as smoke, dust, or pollen. The airways narrow and produce excess mucus, making it difficult to breathe.]] In essence, asthma is the result of an abnormal immune response in the bronchial airways. The airways of asthmatics are "hypersensitive" to certain triggers, also known as stimuli (see below). In response to exposure to these triggers, the bronchi (large airways) contract into spasm (an "asthma attack"). Inflammation soon follows, leading to a further narrowing of the airways and excessive mucus production, which leads to coughing and other breathing difficulties. There are seven categories of stimuli:
- allergens, typically inhaled, which include waste from common household insects, such as the house dust mite and cockroach, grass pollen, mould spores and pet epithelial cells;
- medications, including aspirin and the common β-adrenergic antagonist (beta blockers);
- air pollution, such as ozone, nitrogen dioxide, and sulfur dioxide, which is thought to be one of the major reasons for the high prevalence of asthma in urban areas;
- various industrial compounds and other chemicals, notably sulfites; chlorinated swimming pools generate chloramines—monochloramine (NH2Cl), dichloramine (NHCl2) and trichloramine (NCl3)—in the air around them, which are known to induce asthma;
- early childhood infections, especially viral respiratory infections;
- exercise, the effects of which differ somewhat from those of the other triggers; and
- emotional stress, which is poorly understood as a trigger.

Bronchial inflammation

The mechanisms behind allergic asthma—i.e., asthma resulting from an immune response to inhaled allergens—are the best understood of the causal factors. In both asthmatics and non-asthmatics, inhaled allergens that find their way to the inner airways are ingested by a type of cell known as antigen presenting cells, or APCs. APCs then "present" pieces of the allergen to other immune system cells. In most people, these other immune cells (TH0 cells) "check" and usually ignore the allergen molecules. In asthmatics, however, these cells transform into a different type of cell (TH2), for reasons that are not well understood. The resultant TH2 cells activate an important arm of the immune system, known as humoral immune system. The humoral immune system produces antibodies against the inhaled allergen. Later, when an asthmatic inhales the same allergen, these antibodies "recognize" it and activate a humoral response. Inflammation results: chemicals are produced that cause the airways to constrict and release more mucus, and the cell-mediated arm of the immune system is activated. The inflammatory response is responsible for the clinical manifestations of an asthma attack. The following section describes this complex series of events in more detail.

The immune response

When an inhaled antigen becomes trapped in the airways, it is enzymatically degraded into shorter peptides by APCs such as dendritic cells. APCs express the peptides derived from the antigen on the cell surface, in what is known as the binding groove of the class II major histocompatiblity complex (MHC) molecule. Now located on the cell surface, the antigen-MHC complex is presented to T cells, which express a receptor that is specific to the MHC II peptide. Presented with the antigen-MHC II complex, T helper 0 (TH0) cells become activated and start to differentiate into either T helper type 1 (TH1) or type 2 (TH2) cells. The selective differentiation of TH0 cells has profound consequences for the immune system: TH1 cell production leads to cell-mediated immunity, while the production of predominantly TH2 cells provides humoral immunity. The resulting balance of TH1 or TH2 cells is a crucial variable in the development of asthma; the dominance of the TH2 cell type appears to be necessary for the development of asthma. In one study, mice that lacked the ability to create TH1 cells displayed an asthma-like phenotype. The variables that decide the fate of TH1 vs. TH2 cells are not well understood, but depend on many factors, including childhood exposure to infectious agents and the cytokines elicited by those agents. One cytokine secreted by TH2 cells—IL-4—combined with the action of other cytokines induces synthesis by antigen-stimulated B cells of IgE, an allergen-specific antibody. IgE binds allergens and then receptors on mast cells, basophils, and eosinophils in the airway epithelium. Subsequent exposure of the same antigen to these cells in the airway epithelium initiates the acute-phase reaction of asthma. Stimulated mast cells in the airway release preformed granules of mediators such as histamine, eicosanoids, and cytokines. These molecules are responsible for the symptoms of asthma. They affect the mucosa of the airways, increasing mucosal edema, and mucus production, smooth muscle constriction, and recruit other immune cells, thereby exacerbating the reaction. The late phase of an asthmatic reaction is characterized by an influx of inflammatory and immune cells during the first several hours after antigen exposure. These cells—particularly eosinophils—secrete a series of cytokines, leukotrienes, and polypeptides, which contribute to hyperresponsiveness, mucus secretion, bronchoconstriction, and sustained inflammation.

Pathogenesis

The fundamental problem in asthma appears to be immunological: young children in the early stages of asthma show signs of excessive inflammation in their airways. Epidemiological findings give clues as to the pathogenesis: the incidence of asthma seems to be increasing worldwide, and asthma is now very much more common in affluent countries. One theory of pathogenesis is that asthma is a disease of hygiene. In nature, babies are exposed to bacteria and other antigens soon after birth, "switching on" the TH1 lymphocyte cells of the immune system that deal with bacterial infection. If this stimulus is insufficient—as it may be in modern, clean environments—then TH2 cells predominate, and asthma and other allergic diseases may develop. This "hygiene hypothesis" may explain the increase in asthma in affluent populations. The TH2 lymphocytes and eosinophil cells that protect us against parasites and other infectious agents are the same cells responsible for the allergic reaction. In the developed world, these parasites are now rarely encountered, but the immune response remains and is wrongly triggered in some individuals by certain allergens. Another theory is based on the correlation of air pollution and the incidence of asthma. Although it is well known that substantial exposures to certain industrial chemicals can cause acute asthmatic episodes, it has not been proved that air pollution is responsible for the development of asthma. In Western Europe, most atmospheric pollutants have fallen significantly over the last 40 years, while the prevalence of asthma has risen.

Treatment

The most effective treatment for asthma is identifying triggers, such as pets or aspirin, and limiting or eliminating exposure to them. Desensitization is commonly attempted, but has not been shown to be effective. As is common with respiratory disease, smoking adversely affects asthmatics in several ways, including an increased severity of symptoms, a more rapid decline of lung function, and decreased response to preventive medications. Asthmatics who smoke typically require additional medications to help control their disease. Furthermore, exposure of both nonsmokers and smokers to secondhand smoke is detrimental, resulting in more severe asthma, more emergency room visits, and more asthma-related hospital admissions. Smoking cessation and avoidance of those who smoke is strongly encouraged in asthmatics. The specific medical treatment recommended to patients with asthma depends on the severity of their illness and the frequency of their symptoms. Specific treatments for asthma are broadly classified as relievers, preventers and emergency treatment. The Expert panel report 2: Guidelines for the diagnosis and management of asthma (EPR-2) of the U.S. National Asthma Education and Prevention Program, and the British guideline on the management of asthma are broadly used and supported by many doctors. Bronchodilators are recommended for short-term relief in all patients. For those who experience occasional attacks, no other medication is needed. For those with mild persistent disease (more than two attacks a week), low-dose inhaled glucocorticoids—or alternatively, an oral leukotriene modifier, a mast-cell stabilizer, or theophylline—may be administered. For those who suffer daily attacks, a higher dose of glucocorticoid in conjunction with a long-acting inhaled β-2 agonist may be prescribed; alternatively, a leukotriene modifier or theophylline may substitute for the β-2 agonist. In severe asthmatics, oral glucocorticoids may be added to these treatments during severe attacks. For those in whom exercise can trigger an asthma attack (exercise-induced asthma), higher levels of ventilation and cold, dry air tend to exacerbate attacks. For this reason, activities in which a patient breathes large amounts of cold air, such as cross-country skiing, tend to be worse for asthmatics, whereas swimming in an indoor, heated pool, with warm, humid air, is less likely to provoke a response.

Relief medication

skiing]] Symptomatic control of episodes of wheezing and shortness of breath is generally achieved with fast-acting bronchodilators. These are typically provided in pocket-sized, metered-dose inhalers (MDIs—see the image to the right). In young sufferers, who may have difficulty with the coordination necessary to use inhalers, or those with a poor ability to hold their breath for 10 seconds after inhaler use (generally the elderly), an asthma spacer is used. The spacer is a plastic cylinder that mixes the medication with air in a simple tube, making it easier for patients to receive a full dose of the drug (see top image) and allows for the active agent to be dispersed into smaller, more fully inhaled bits. A nebulizer—which provides a larger, continuous dose—can also be used. Nebulizers work by vapourizing a dose of medication in a saline solution into a steady stream of foggy vapor, which the patient inhales continuously until the full dosage is administered. There is no clear evidence, however, that they are more effective than inhalers used with a spacer. Nebulizers may be helpful to some patients experiencing a severe attack. Such patients may not be able to inhale deeply, so regular inhalers may not deliver medication deeply into the lungs, even on repeated attempts. Since a nebulizer delivers the medication continuously, it is thought that the first few inhalations may relax the airways enough to allow the following inhalations to draw in more medication. Relievers include:
- Short-acting, selective beta2-adrenoceptor agonists (salbutamol [albuterol], levalbuterol, terbutaline, bitolterol, pirbuterol, procaterol, fenoterol, reproterol). Tremors, the major side effect, have been greatly reduced by inhaled delivery, which allows the drug to target the lungs specifically; oral and injected medications are delivered throughout the body. There may also be cardiac side effects at higher doses, such as elevated heart rate or blood pressure; with the advent of selective agents, these side effects have become less common. Patients must be cautioned against using these medicines too frequently, as with such use their efficacy may decline, resulting in an exacerbation of symptoms which may lead to refractory asthma and death.
- Older, less selective adrenergic agonists, such as inhaled epinephrine and ephedrine tablets—both of which, unlike other medications, are available over the counter in the US under the [http://www.primatene.com Primatene] brand. Cardiac side effects, although uncommon, occurred more often with the less selective drugs. They also have the disadvantage of providing a shorter period of relief than the selective bronchodiolators. Nowadays, they are usually avoided in patients with heart disease. In emergencies, these drugs were sometimes administered by injection in severe attacks. Their use in this situation has declined.
- Anticholinergic medications, such as ipratropium bromide may be used instead. They have no cardiac side effects and thus can be used in patients with heart disease; however, they take up to an hour to achieve their full effect and are not as powerful as the β2-adrenoreceptor agonists.

Prevention medication

Current treatment protocols recommend prevention medications such as an inhaled corticosteroid, which helps to suppress inflammation and reduces the swelling of the lining of the airways, in anyone who has frequent (greater than twice a week) need of relievers or who has severe symptoms. If symptoms persist, additional preventive drugs are added until the asthma is controlled. With the proper use of prevention drugs, asthmatics can avoid the complications that result from overuse of relief medications. Asthmatics sometimes stop taking their preventative medication when they feel fine and have no problems breathing. This often results in further attacks, and no long-term improvement. Preventive agents include the following.
- Inhaled glucocorticoids (fluticasone, budesonide, beclomethasone, mometasone, flunisolide, and triamcinolone).
- Antimuscarinics/anticholinergics (ipratropium, oxitropium), which have a mixed reliever and preventer effect. They are rarely used in asthma.
- Leukotriene modifiers (montelukast, zafirlukast, pranlukast, and zileuton).
- Mast cell stabilizers (cromoglicate (cromolyn), and nedocromil).
- Methylxanthines (theophylline and aminophylline), which are sometimes considered if sufficient control cannot be achieved with inhaled glucocorticoids and long-acting β-agonists alone.
- Antihistamines, often used to treat allergic symptoms that may underlie the chronic inflammation. In more severe cases, hyposensitization ("allergy shots") may be recommended.
- Omalizumab, an IgE blocker; this can help patients with severe allergic asthma that does not respond to other drugs. However, it is expensive and must be injected.
- Methotrexate is occasionally used in some difficult-to-treat patients.
- If chronic acid indigestion (GERD) contributes to a patient's asthma, it should also be treated, because it may prolong the respiratory problem.

Long-acting β2-agonists

Long-acting bronchodilators (LABD) give a 12-hour effect, and are used to give a smoothed symptomatic effect (used morning and night). While patients report improved symptom control, these drugs do not replace the need for routine preventers, and their slow onset means the short-acting dilators may still be required. Currently available long-acting beta2-adrenoceptor agonists include salmeterol, formoterol, bambuterol, and sustained-release oral albuterol. Combinations of inhaled steroids and long-acting bronchodilators are becoming more widespread; the most common combination currently in use is fluticasone/salmeterol (Advair in the United States, and Seretide in the UK).

Emergency treatment

When an asthma attack is unresponsive to a patient's usual medication, other treatments are available to the physician or hospital:
- oxygen to alleviate the hypoxia (but not the asthma per se) that results from extreme asthma attacks;
- nebulized salbutamol (2.5-5 mg), usually three in rapid succession ("back-to-back");
- systemic steroids, oral or intravenous (prednisone, prednisolone, methylprednisolone, dexamethasone, or hydrocortisone)
- other bronchodilators that are occasionally effective when the usual drugs fail:
  - nonspecific beta-agonists, injected or inhaled (epinephrine, isoetharine, isoproterenol, metaproterenol);
  - anticholinergics, IV or nebulized, with systemic effects (glycopyrrolate, atropine);
  - methylxanthines (theophylline, aminophylline);
  - inhalation anesthetics that have a bronchodilatory effect (isoflurane, halothane, enflurane);
  - the dissociative anesthetic ketamine, often used in endotracheal tube induction
  - magnesium sulfate, intravenous; and
- intubation and mechanical ventilation, for patients in or approaching respiratory arrest.

Alternative medicine

Many asthmatics, like those who suffer from other chronic disorders, use alternative treatments; surveys show that roughly 50% of asthma patients use some form of unconventional therapy. There are little data to support the effectiveness of most of these therapies. A Cochrane systematic review of acupuncture for asthma found no evidence of efficacy. A similar review of air ionisers found no evidence that they improve asthma symptoms or benefit lung function; this applied equally to positive and negative ion generators. A study of "manual therapies" for asthma, including osteopathic, chiropractic, physiotherapeutic and respiratory therapeutic maneuvers, found no evidence to support their use in treating asthma; these maneuvers include various osteopathic and chiropractic techniques to "increase movement in the rib cage and the spine to try and improve the working of the lungs and circulation"; chest tapping, shaking, vibration, and the use of "postures to help shift and cough up phlegm". On the other hand, one meta-analysis found that homeopathy has a potentially mild benefit in reducing symptom intensity; however, the number of patients involved in the analysis was small, and subsequent studies have not supported this finding. Several small trials have suggested some benefit from various yoga practices, ranging from integrated yoga programs—"yogasanas, Pranayama, meditation, and kriyas"—to sahaja yoga, a form of meditation. A randomized, controlled trial of just 39 patients suggested that the Buteyko method may moderately reduce the need for beta-agonists among asthmatics, but found no objective improvement in lung function. See also Complementary and alternative medicine.

Prognosis

The prognosis for asthmatics is good, especially for children with mild disease. For asthmatics diagnosed during childhood, 54% will no longer carry the diagnosis after a decade. The extent of permanent lung damage in asthmatics is unclear. Airway remodelling is observed, but it is unknown whether these represent harmful or beneficial changes. Although conclusions from studies are mixed, most studies show that early treatment with glucocorticoids prevents or ameliorates decline in lung function as measured by several parameters. For those who continue to suffer from mild symptoms, corticosteroids can help most to live their lives with few disabilities. The mortality rate for asthma is low, with around 6000 deaths per year in a population of some 10 million patients in the United States. Better control of the condition may help prevent some of these deaths.

Epidemiology

disabilities Asthma is usually diagnosed in childhood. The risk factors for asthma include:
- a personal or family history of asthma or atopy;
- triggers (see Pathophysiology above);
- premature birth or low birth weight;
- viral respiratory infection in early childhood;
- maternal smoking;
- being male, for asthma in prepubertal children; and
- being female, for persistence of asthma into adulthood. There is a reduced occurrence of asthma in people who were breast-fed as babies. Current research suggests that the prevalence of childhood asthma has been increasing. According to the Centers for Disease Control and Prevention's National Health Interview Surveys, some 9% of US children below 18 years of age had asthma in 2001, compared with just 3.6% in 1980 (see figure). The World Health Organization (WHO) reports that some 8% of the Swiss population suffers from asthma today, compared with just 2% some 25–30 years ago. Although asthma is more common in affluent countries, it is by no means a problem restricted to the affluent; the WHO estimate that there are between 15 and 20 million asthmatics in India. In the U.S., urban residents, Hispanics, and African Americans are affected more than the population as a whole. Globally, asthma is responsible for around 180,000 deaths annually.

Asthma and athletics

Asthma appears to be more prevalent in athletes than in the general population. One survey of participants in the 1996 Summer Olympic Games showed that 15% had been diagnosed with asthma, and that 10% were on asthma medication. There appears to be a relatively high incidence of asthma in sports such as cycling, mountain biking, and long-distance running, and a relatively low incidence in weightlifting and diving. It is unclear how much of these disparities are because of the effects of training in the sport, and self-selection of sports that may appear to minimize the triggering of asthma. It has also been suggested that some professional athletes who do not suffer from asthma claim to do so in order to obtain special permits to use certain performance-enhancing drugs.

See also


- Atopy.
- Hopkins syndrome.
- Immune response.

References

# Lilly CM. Diversity of asthma: Evolving concepts of pathophysiology and lessons from genetics. J Allergy Clin Immunol. 2005;115(4 Suppl