Effects of Ventilatory Patterns on Arterial Oxygenation after Near-drowning in Sea Water

Abstract

Forty-three dogs were anesthetized and subjected to aspiration of 22 ml/kg of sea water. After 5 minutes, fluid was drained from the lungs by gravity; 33.1 ± 5.9 ml/kg were recovered. Thirty-four dogs were apneic at this time and were treated with intermittent positive-pressure ventilation with a self-inflating bag. Forty-five minutes later, the 40 animals that survived were divided into four equal groups; one group breathed spontaneously and served as a control, the second was treated with IPPV, the third breathed spontaneously against 10 cm H2O PEEP, and the fourth received IPPV plus PEEP (i.e., CPPV). Arterial oxygen tensions of the animals in both groups with PEEP significantly increased during the 75-minute treatment period. By 48 hours two more dogs had died; however, Pa2's had returned to normal in the 38 that survived, regardless of me mode of treatment It is concluded that gravity drainage and immediate mechanical ventilation of victims who aspirate large quantities of sea water are important, since 40 of the 43 animals were resuscitated after being submerged for 5–10 minutes. Blood-gas data showed that positive end-expiratory pressure, with or without mechanical ventilation, significantly increased PaO2 after aspiration of sea water, suggesting that it is indicated in the treatment of sea-water near-drowning victims. Two case reports of human victims of near-drowning in sea water which support the animal studies are presented.