A standardized dog experiment was designed to simulate human victims of submersion who seem to first develop laryngospasm, followed by flooding of the lungs. The tracheal tube of lightly anesthetized dogs was clamped until the onset of apnea. The lungs were then flooded for 30 seconds with fresh water or sea water, or apnea was permitted to continue for a comparable period without flooding. Resuscitation was attempted with intermittent positive pressure breathing (IPPB), utilizing room air. All control dogs (obstructive asphyxia, without flooding) survived. Freshwater drowning caused mild arterial hypotension, severe rise in venous pressure and bradycardia, followed by sudden ventricular fibrillation in 1–4 minutes in spite of IPPB. Sea-water drowning caused severe arterial hypotension, slight rise in venous pressure and bradycardia. IPPB led to partial reoxygenation and partial restoration of circulation. When IPPB was discontinued all dogs started breathing spontaneously, but within a few minutes developed asystole with pulmonary edema.
Submitted on January 25, 1960
- Copyright © 1960 the American Physiological Society