Drowning

Published on 23/03/2015 by admin

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Chapter 64 Drowning

Linda Quan, MD, Brian Coleman, MD, MS

1 How should the terms near drowning and drowning be applied to submersion victims? What is a drowning?

In 2002, the World Congress on Drowning developed universal terminology to improve interpretation and comparison of reported data. Previously used terminology, such as near-drowning, secondary, wet, dry, and silent drowning have been abandoned. Drowning is immersion in a liquid medium that results in some degree of primary respiratory impairment and may result in survival or death. The term drowning should not reflect clinical course or final outcome.

Bierens J: Handbook on Drowning. Springer, Netherlands, 2004.

Idris AH: Recommended guidelines for uniform reporting of data from drowning: The “Utstein style.” Resuscitation 59:45–57, 2003.

Zuckerbraun NS: Pediatric drowning: Current management strategies for immediate care. Clin Pediatr Emerg Med 6 49–56, 2005.

2 Is cardiopulmonary resuscitation indicated for every patient in cardiac arrest following a drowning?

Survival rates from cardiac arrest following drowning are among the highest, 20–31%, reported in pediatric cardiac arrest, although it is unclear why. To be effective, resuscitation should begin as soon as possible after retrieval from the water, at the scene. However, survival from prolonged (> 25 minutes) non–icy water drownings is essentially zero, as is survival following cardiopulmonary resuscitation for > 25 minutes without return of spontaneous circulation (a perfusing blood pressure). There are clearly some patients who are dead at the scene for whom efforts are futile.

Orlowski JP: Prognostic factors in pediatric cases of drowning and near-drowning. JACEP 8:176–179, 1979.

3 What is a cold water drowning?

The term cold water should be abandoned for the evidence-based predictor icy water. While there are rare, isolated cases of successful resuscitation and intact survival after long drowning in cold waters, these dramatic cases usually occurred in waters colder than 10° C. Nonicy cold water, unfortunately, is still too warmly defined by some enthusiastic resuscitators and is assigned greater powers than are supported by well-done studies.

Wollenek G: Cold water submersion and cardiac arrest in treatment of severe hypothermia with cardiopulmonary bypass. Resuscitation 52:255–263, 2002.

4 Is hypothermia protective?

Hypothermia can dramatically decrease the cerebral metabolic rate, with a resultant decrease in the oxygen requirements of the brain and greater tolerance of hypoxia. However, for hypothermia to be protective, it must precede the onset of hypoxic injury. The very rapid cooling required to produce protective hypothermia is usually not accomplished in the usual nonicy water drowning; in these patients, hypothermia upon arrival to the emergency department (ED) predicts a bad, not a good, outcome.

Biggart MJ: Effect of hypothermia and cardiac arrest on outcome of near-drowning accidents in children. J Pediatr 117:179–183, 1990.

5 How should an icy cold water drowning be managed differently from a warm water drowning?

A patient who has had a truly icy water drowning should be managed aggressively because of the possibility of intact survival. Prolonged and maximal resuscitative efforts, including cardiopulmonary bypass or extracorporeal membrane oxygenation, may be indicated for the icy water submersion but have not been effective for warm water submersion patients. Because icy water drownings are anecdotal reports, predictors and likelihood ratios for survival from icy water submersions are not available. Most would agree, however, that for nonicy water drownings, failure to restore a circulating cardiac rhythm within about 30 minutes after rewarming to 32–35° C suggests that further efforts are unlikely to be successful.

Wollenek G, Honarwar N, Golej J, Marx M: Cold water submersion and cardiac arrest in treatment of severe hypothermia with cardiopulmonary bypass. Resuscitation 52:255–263, 2002.

6 Is there a clinical difference between a salt water AND fresh water drowning?

There is none. A large clinical study showed no real difference in the clinical presentation of adults who drowned in salt or fresh waters, thus invalidating the mythic physiologic changes reported in one animal study. Clinical experience dictates that both salt water– and fresh water–drowned patients may develop pulmonary edema, anemia is rare, and electrolytes are usually normal. The explanation may lie in the fact that most humans do not aspirate large volumes of water. Furthermore, the pulmonary response to drowning, especially the development of pulmonary edema, relates to other factors besides the salinity of the aspirated fluid.

Modell JH: Drowning. N Engl J Med 328:253–256, 1993.

7 What are the tenets of management in resuscitation of the unresponsive drowning patient?

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