Biología, Botánica, Genética y Zoología
Deficiency of oxygen and excess of carbon dioxide in the blood and body tissues.
Asphyxia, often referred to as suffocation, usually results from an interruption of breathing due to mechanical blockage of the breathing passages, paralysis of the respiratory muscles following electric shock, inundation of the lungs as may occur with pneumonia or drowning, or substitution of carbon monoxide for oxygen in the red blood cells.
Symptoms of asphyxia vary but may include light-headedness, nausea, and gasping, followed by unconsciousness and death. An area quickly affected is the cerebral cortex, the brain center for speech and other conscious behavior; it can be irreparably damaged by as little as five minutes of oxygen deprivation. Damage to the medulla may result in interference with the heartbeat or other involuntary processes. Artificial respiration is the most practical first-aid procedure for asphyxia. Trained personnel can provide oxygen and employ techniques to maintain the heart rate and respiration.
Drowning is asphyxiation from water or liquid being inhaled into the airways, blocking the passage of air to the lungs. Water inhaled into the windpipe causes violent choking. The choking irritates the mucous membranes of the airways causing a large amount of sticky mucus to form. The mucus, mixed with the water and agitated by violent attempts to breathe, turns into a thick sticky foam which fills the windpipe.
Most drownings occur when the victim submerges in a body of water. A small number of "drowning" deaths among swimmers are actually caused by their hearts stopping from the shock of submersion. Most commonly, a drowning victim has a violent spasm of the neck, throat, and chest muscles. This prevents breathing. The victim submerges, inhaling water. The victim may stay submerged the first time he goes under. Or he may go under and surface many times, until he can no longer struggle to the surface. Loss of consciousness often occurs fast. Because the human body is heavier than water, when unconsciousness occurs, the victim sinks and tends to lay at the bottom with the head down. Breathing may continue briefly with varying amounts of water inhaled. The heart may beat briefly after breathing stops. Death by asphyxia occurs within a few minutes. Banning strong currents, a body sinks fast. It often comes to rest at a point close to where it was last seen on the surface.
Rigor mortis may start early because of violent muscular struggle. Postmortem lividity occurs, but is often a light red in color and is most noted in the head and upper body. This is because of the body's tendency to sink head down. The foam that formed in the airway may exude from the mouth and nose. Often, the victim's hands will be grasping gravel, mud, or grass. The hands and fingertips may be scratched from violent grasping efforts.
The palms may be cut by the fingernails during the hands' violent clenching motions. And medical laboratory study of the victim's bone marrow may show microscopic bodies. These factors are good circumstantial signs that the victim was alive when he entered the water.
After a few hours, depending on temperature and movement of the water, postmortem changes peculiar to submersion begin to occur.
The skin, especially on the hands and feet, becomes bleached and waterlogged. Palms develop a very wrinkled condition called washer-woman hands. The constant churning of water currents or long periods of submersion may cause maceration. This is the wearing away of skin and flesh, especially of the hands and feet. Mutilation may occur from propellers of boats. This causes the appearance of postmortem dismemberment.
Parts of the body, notably the face, may be eaten by marine life. As bacteria mounts in the body, putrefaction begins. As putrefaction progresses, gases build up in the tissues, organs and body cavities. The body becomes distended with gas. This makes the white foam in the airway come out of the nose and mouth. As the gases build up, the body becomes buoyant. Warm water speeds putrefaction; cold water slows it. In warm water, buoyancy may occur in a couple of days. In winter, the action may be slowed for weeks or until spring. As putrefaction advances, the skin loosens from the tissues. Sections of skin, especially hands, feet, and scalp, may fall from the body.
Unless a body is heavily weighted down or firmly caught on underwater debris, buoyancy will eventually cause it to rise to the top and float. If a body is prevented from rising, the gases eventually escape. Then buoyancy leaves and a body may stay down forever. When a "floater" rises and is exposed to the air, decomposition proceeds at a much faster rate.
Prolonged submersion and decaying may dim or destroy the external signs of asphyxia. Signs of violence or other cause of death may also be lost. Prolonged submergence makes death by drowning medically difficult to diagnose. But medical evidence may show signs of asphyxia like foam in the airways, and an enlarged heart. It may also show changes in the blood from water absorbed during drowning. Algae and other substances from the water may be found in the stomach or airways. Chemical tests during an autopsy can show if the person was alive when he entered the water. But chemical tests are nonspecific, and none are diagnostic of drowning.
Suicidal drownings in places like bathtubs are hard to distinguish from accidents unless a reason is suggested or some other means of suicide was also attempted. Check for marks which may show suicidal intent. A weighted body strongly suggests homicide. But suicides may weight their bodies to speed drowning and stop recovery. Inspect weighted bodies carefully for injuries suggesting homicide. See if the binding and weighting method could have been done by the victim. Check for self-inflicted injuries such as cut wrists or any other sign of suicide.
Homicidal drownings are rare. Unless accompanied by signs of homicidal violence or other such conditions, the autopsy shows only signs of asphyxia by drowning. There have been times when submerged bodies have shown no signs of violence, but, after the body dried out, bruise marks and small abrasions appeared that could not be seen when wet.
The Heimlich Controversy in Near-Drowning Resuscitation
As a result of renewed electronic and print media exposure, the Heimlich Controversy has once more reared its head creating a confusing message for lifeguard and other rescue personnel regarding the resuscitation procedures to be used when confronted with a near-drowning resuscitation incident. The purpose of this article is to present readers with the information needed to make a sound decision in this matter.
According to Dr. Henry Heimlich, "drowning victims die when their lungs fill with water. Air can't get into water filled lungs. Heimlich maneuvers remove the water from the lungs in 4 - 6 seconds. Pressing upward on the diaphragm jump-starts breathing. Many drowning victims have been saved by rescuers performing the Heimlich maneuver, even after CPR failed." Ellis and Associates have advanced this concept by endorsing the Heimlich Maneuver as the first step for saving drowning victims, even though this protocol is contraindicated by the Resuscitation Standards advocated by the American Heart Association and the American Red Cross.
Heimlich advocates that given the low complication rate associated with the Heimlich Maneuver and the inability of rescuers to readily determine if a drowning victim's airway is blocked by fluid, the Heimlich Maneuver should be applied as the first step to ensure the airway is clear. The Maneuver should be performed until water no longer flows from the mouth, which usually occurs after 2 - 4 applications, over a period of 4 - 6 seconds.
There have been numerous reported cases which state that the Heimlich Maneuver worked when all other lifesaving measures failed. In fact a Patrick Institute study found that in a series of unconscious, non-breathing pulseless drowning victims, 87% survived when the Heimlich
Maneuver was performed, whereas only 27% survived when CPR was performed without the Heimlich Maneuver. According to University of Houston Professor John Hunsucker, in a study conducted for the National Pool and Waterparks Association, that in 27 drowning incidents reported by NPWPA trained lifeguards, 24 victims responded by breathing from the Heimlich procedures alone and only three required CPR after the Heimlich was administered.
The application of the Heimlich maneuver as the initial and perhaps only step for opening the airway in all near-drowning victims is contrary to current resuscitation guidelines for the treatment of near-drowning victims established by the Emergency Cardiac Care (ECC) Committee of the American Heart Association. To help resolve this difference, the Institute of
Medicine (IOM) convened an expert committee to determine when the Heimlich maneuver should be used in the treatment of near-drowning victims, if at all. During its deliberations, the IOM Committee on the Treatment of Near-Drowning Victims met with Dr. Heimlich and his colleagues and considered literature reviews of clinical and basic research on drowning, scientific articles on pertinent pathophysiological states involving fluid in the airways, and its own clinical experience.
The committee concludes that, although the Heimlich maneuver is useful for the removal of aspirated solid foreign bodies, there is no evidence that death from drowning is frequently caused by aspiration of a solid foreign body that is not effectively treated by the current ECC recommendations. The committee further finds that the evidence is insufficient to support the proposition that the Heimlich maneuver is useful for the removal of aspirated liquid. Moreover, because there is no evidence to support Heimlich's hypothesis that substantial amounts of water are aspirated by near-drowning victims or that such aspirated liquid causes brain damage and death, the committee finds that the available evidence does not support routine use of the Heimlich maneuver in the care of near-drowning victims.
The committee also has a series of concerns about the routine use of the Heimlich maneuver for treatment of near-drowning, because of:
(a) the amount of time it would take to repeat this maneuver until the patient is no longer expelling water (as recommended by Heimlich) and how long this would delay the initiation of artificial ventilation;
(b) possible complications of the Heimlich maneuver, especially if the near drowning is associated with a cervical fracture; and
(c) the prospect of teaching rescue workers a different protocol than that which is taught at present for resuscitating victims of cardiopulmonary arrest from all causes other than drowning.
The committee therefore concludes that given the present state of basic science and clinical knowledge about near drowning, the current ECC recommendations for establishment of the airway and ventilation should not be changed. These recommendations state that an abdominal thrust should be performed only after ventilation has been shown to be ineffective and then only to remove a solid foreign body.
Any measure that causes air to flow in and out of a person's lungs when natural breathing is inadequate or ceases, as in respiratory paralysis, drowning, electric shock, choking, gas or smoke inhalation, or poisoning. Respiration can be taken over by an artificial lung (especially in respiratory paralysis), a pulmotor, or any other type of mechanical respirator.
In emergency situations, however, when no professional help is available, rescuers undertake the mouth-to-mouth or mouth-to-nose method of artificial respiration. First, any foreign material is swept out of the mouth with the hand. The victim is placed on his back, with the head tilted backward and chin pointing upward so that the tongue does not block the throat. The reviver's mouth is then placed tightly over the victim's mouth or nose, with the victim's nostrils or mouth held shut.
For a small child or infant, the reviver places his mouth firmly over the mouth and nose. The reviver takes a deep breath and blows into the victim's mouth, nose, or both. If there is no exchange of air, the reviver checks the position of the head. If there is still no exchange, the victim should be turned on his side and rapped between the shoulder blades to dislodge any foreign matter that may be blocking the air passages. A child can be held by the ankles and rapped between the shoulder blades.
The reviver stops blowing when the chest expands, turns his head away, and listens for exhalation. If the victim is an adult, blowing should be vigorous, at the rate of about 12 breaths per minute. A child's breaths should be shallower, about 20 per minute, and an infant's breaths should come in short puffs. When victims vomit, they must be turned on their side and the airway cleaned before continuing artificial respiration.
If the victim has had the larynx removed, the above method is used, but the reviver must breathe into the stoma (surgical opening made in front of neck for breathing). Breathing into the subject should be continued until natural breathing resumes or until professional help arrives. Since the heart often stops beating when breathing is interrupted, cardiopulmonary resuscitation (CPR) is typically administered simultaneously. This entails compressing the chest above the heart at 60 or more thrusts per minute, with two breaths being administered after every 15 chest thrusts.
Device used to revive a person whose normal breathing has been disrupted. Several types are in wide use. The automatic tank resuscitator consists of a face mask that fits tightly over the nose and mouth and is connected by a tube to one or more tanks of gas. Pressurized oxygen enters the mask through the action of automatic valves.
A second tank may contain carbon dioxide, small amounts of which are mixed with oxygen, serving to activate the respiratory center in the brain. In a similar device, the manual tank resuscitator, the oxygen flow is regulated by the operator.
The self-inflating, bag-mask resuscitator consists of an airtight mask that fits over the nose and mouth, a self-inflating bag, and often an oxygen tube connector. When the bag is squeezed, air or oxygen enters the patient's lungs. The bag inflates automatically when released. Air from the lungs leaves the mask by an escape valve without returning to the bag
Cardiopulmonary Resuscitation (CPR)
Emergency procedure used to treat victims of cardiac and respiratory arrest. CPR can be done in a hospital with drugs and special equipment or as a first-aid technique. In either case it is done with great urgency to avoid the brain damage or death that result from four to six minutes without oxygen.
The first-aid procedure combines external heart massage (to keep the blood flowing through the body) with artificial respiration (to keep air flowing in and out of the lungs). The victim is placed face up and prepared for artificial respiration. The person administering CPR places his or her hands (one on top of the other, with fingers interlocked) heel down on the victim's breastbone, leans forward, and makes 15 quick, rhythmical compressions (at a rate of about one per second) of about 2 in. (5 cm). This is followed by two breaths, administered using the mouth-to-mouth method of artificial respiration. CPR for infants and children differs in the ratio of compressions to breaths, and the compression of the chest is only 1 to 1.5 in. (2.5 to 3.8 cm). Ideally the procedure is done by two people, one to give mouth-to-mouth artificial respiration and one to apply external heart massage, and special training is recommended.
Cardiopulmonary resuscitation in the hospital is an aggressive technique employing drugs and defibrillation equipment, which administers electrical shocks to the heart in an attempt to restore the heartbeat. There is some controversy surrounding its use in patients whose prognosis is poor.
When the body or any vital part of it is deprived of oxygen, asphyxia occurs. Death from asphyxia alone is most often due to natural or accidental causes. Many diseases and infections can hinder airways. And foreign bodies like meat or bone can become trapped in the throat or windpipe, causing asphyxia. Food particles are often the cause of accidental choking deaths in adults.
Choking deaths of children are common from food and from small plastic or metal toys. And pressure on the outside of the chest that restricts breathing can cause asphyxia. This pressure can occur in cave-ins, building collapses, or traffic accidents.
Inhaling chemicals like ammonia, chloroform, carbon monoxide, and carbon dioxide also may cause asphyxia. Sometimes these chemicals are the cause of suicidal or homicidal deaths. Homicide and suicide by asphyxia alone are rare. But in learning the reasons for death by asphyxia, anything suspicious must be pursued through background investigation and autopsy. Only then can the death be ruled accidental or natural.
Accidents caused by submersion, suffocation and foreign bodies
Accidental drowning and submersion:
- Includes: immersion
- Excludes: diving accident (NOS) (resulting in injury except drowning)
diving with insufficient air supply
Drowning and submersion due to:
- machinery accident
- transport accident
- effect of high and low air pressure
- injury from striking against objects while in running water
- while water-skiing
- fall from water skis with submersion or drowning
- Excludes: accident to water-skier involving a watercraft and resulting in submersion or other injury.
While engaged in other sport or recreational activity with diving equipment:
- scuba diving
- skin diving
- underwater spear fishing
While engaged in other sport or recreational activity without diving equipment:
- fishing or hunting, except from boat or with diving equipment
- ice skating
- playing in water
- voluntarily jumping from boat, not involved in accident, for swim
- wading in water
- Excludes: jumping into water to rescue another person
while swimming or diving for purposes other than recreation or sport
marine salvage (with diving equipment)
pearl diving (with diving equipment)
placement of fishing nets (with diving equipment)
rescue (attempt) of another person (with diving equipment)
underwater construction or repairs (with diving equipment)
Other accidental drowning or submersion:
- drowning in: quenching tank
- unspecified accidental drowning or submersion: accidental fall into water
Inhalation and ingestion of food causing obstruction of respiratory tract or suffocation:
- aspiration and inhalation of food [any] (into respiratory tract) NOS
- asphyxia by food [including bone, seed in food, regurgitated food]
- choked on food [including bone, seed in food, regurgitated food]
- suffocation by food [including bone, seed in food, regurgitated food]
- compression of trachea by food lodged in esophagus
- interruption of respiration by food lodged in esophagus
- obstruction of respiration by food lodged in esophagus
- obstruction of pharynx by food (bolus)
- Excludes: injury, except asphyxia and obstruction of respiratory passage, caused by food.
|obstruction of esophagus by food without mention of asphyxia obstruction of respiratory passage
Inhalation and ingestion of other object causing obstruction of respiratory tract or suffocation:
- aspiration and inhalation of foreign body except food (into respiratory tract)
- foreign object [bean] [marble] in nose
- obstruction of pharynx by foreign body
- compression by foreign body in esophagus
- interruption of respiration by foreign body in esophagus
- obstruction of respiration by foreign body in esophagus
- Excludes: injury, except asphyxia and obstruction of respiratory passage, caused by foreign body
obstruction of esophagus by foreign body without mention of asphyxia or obstruction in respiratory passage
accidental mechanical suffocation
- Excludes: mechanical suffocation from or by:
accidental inhalation or ingestion of:
in bed or cradle
- Excludes: suffocation by plastic bag
Due to lack of air (in closed place):
- accidentally closed up in refrigerator or other airtight enclosed space
- diving with insufficient air supply
Excludes: suffocation by plastic bag.
By falling earth or other substance:
- Excludes: cave-in caused by cataclysmic earth surface movements and eruptions
struck by cave-in without asphyxiation or suffocation
Other specified means:
- accidental hanging, except in bed or cradle
- asphyxia, mechanical
- foreign body accidentally entering eye and adnexa
- Excludes: corrosive liquid
foreign body accidentally entering other orifice
- Excludes: aspiration and inhalation of foreign body, any, (into respiratory tract).