Peritoneal ventilation with oxygen improves outcome after hemorrhagic shock in rats

Objective: In experimental pulmonary consolidation with hypoxemia in rabbit s, peritoneal ventilation (PV) with 100% oxygen (PV-O-2) improved Pao(2). W e hypothesized that PV-O-2 could improve outcome after hemorrhagic shock (H S) with normal lungs, by mitigating dysoxia of the abdominal viscera, Design: Randomized, controlled, laboratory animal study. Setting: University animal research facility. Subjective: Male Sprague-Dawley rats. Interventions: Thirty rats under light anesthesia (N2O/oxygen plus halothan e) and spontaneous breathing underwent blood withdrawal of 3 mL/100 g over 15 mins. After volume-controlled Us phase 1 of 60 mins, resuscitation phase 2 of 60 mins included infusion of shed blood and, if necessary, additional lactated Ringer's solution intravenously to control normotension from 60 t o 120 mins. This was followed by observation phase 3 for 7 days. We randomi zed three groups of ten rats each: group I received PV-O-2, starting at 15 mins of Us at a rate of 40 inflations/min, and a peritoneal "tidal volume" of 6 mt, until the end of phase 2. Group II received the same PV with room air (PV-Air). Control group III was treated without PV. Measurements and Main Results: During the second half of Us phase 1, mean a rterial pressures were higher in the PV-O-2 group I compared with the PV-Ai r group II and control group III (p < .05). All 30 rats survived the 120 mi ns of phases 1 and 2, survival to 7 days was achieved by ten of ten rats in PV-O-2 group I; by nine of ten in PV-Air group II; and by five of ten in c ontrol group III (p < .05 vs. group I; NS vs. group II). survival times of <7 days were 5 days in the one death of group II and ranged between 6 hrs a nd 4 days in the five deaths of group Ill. In 7-day survivors, neurologic d eficit scores (0% to 10% = normal, 100% = death) were normal, ranging betwe en zero and 8%, Necropsies of rats that died during phase 3 showed multiple areas of necrosis of the gut, some with perforations. Necropsies in the fi ve survivors to 7 days of group PI showed marked macroscopic and microscopi c changes (scattered areas of necrosis of stomach and intestine, adhesions, and pale areas in the river). These changes were absent or less severe in the nine survivors of group II. Viscera appeared normal in all ten rats of PV-O-2 group I. Conclusions: Peritoneal ventilation with oxygen during and after severe hem orrhagic shock in rats seems to decrease morbidity and mortality by helping preserve viability of abdominal viscera.