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Abstract
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What is the appropriate terminology to use when referring to patients who have drowned?
The WHO's 2002 World Congress on Drowning defined drowning as "the process of experiencing respiratory impairment from submersion or immersion in liquid" [1]. An important implication of this definition is that drowning is not necessarily a fatal event. Any patient who presents with respiratory symptoms after an immersion or submersion event has "drowned."
Many terms which had previously been used to describe drownings are no longer appropriate. Terms which should no longer be used include near drowning, secondary drowning, wet drowning, dry drowning, active drowning, passive drowning, and silent drowning [2, 3].
What is the pathophysiology of drowning?
When water is aspirated, the initial response is a cough reflex. Significant aspiration may lead to laryngospasm. Unless the drowning event is aborted, cerebral hypoxia will lead to a loss of consciousness after approximately 1 min. While the patient is unconscious a small amount of water enters the lungs causing direct cellular injury, hypoxic vasoconstriction and bronchospasm [2, 3]. Surfactant washout leads to a noncardiogenic pulmonary edema. This edema can be so large in volume that it enters the upper airways where it can be directly visualized during resuscitation. During unconsciousness the swallowing reflex is intact and large volumes of water can enter the stomach, creating a vomiting risk during subsequent resuscitation efforts.
Drowning patients usually experience an initial sinus tachycardia, then as the cardiac tissues experience hypoxia the rhythm develops into bradycardia, pulseless electrical activity, and asystole. Ventricular fibrillation and pulseless ventricular tachycardia are rare [2].
Can drowned patients be classified according to the severity of their symptoms?
A Drowning Severity Classification System was developed by analyzing data from > 41,000 rescues [4]. This system incorporates elements of the physical exam (pulse, respirations, blood pressure, and pulmonary auscultation) to classify drowning severity across 6 Grades (Table 1). This simple classification system provides a valuable tool for early and efficient assessment of drowning severity in either the pre-hospital or ED environments...
Language: en |