The Effects of Endobronchial Insufflation of Air on Cardiopulmonary System in Apneic Dogs / 대한마취과학회지

ABSTRACT

BACKGREOUND Mass casualties from organophosphrous inhalation die from respiratory depression. Gas supplies and equipment are limited for mechanical ventilation of multiple subjects. Endobronchial insufflation of air (EIA) requires only a compresssor and airway catheters. We examined clinical usefulness of EIA in a model of apnea produced by tetrodotoxin (TTX) infusion. METHODS: Five anesthetized dogs were applied the conventional mechanical ventilation (CMV) while 12 mcg/kg TTX was infused IV over 90 min to produce apnea. EIA at 1 L/kg/min was delivered through a 35 cm long 0.8 cm I.D. catheter with a forked end placed astride the carina. Measurements of cardiovascular and respiratory function were made after TTX (time=0) on CMV, and then serially for 4 hours of EIA. RESULTS: All dogs survived through 4 hours study. PaO2 decreased significantly within 30 min and then slowly increased significantly after 60 min. PaCO2 increased significantly within 30 min and decreased significantly after 60 min. HR increased significantly after 20 min and MAP increased significantly after 60 min. Mean SD of PaO2, PaCO2, pHa, SaO2, cardiac output, mean pulmonary pressure, mean arterial pressure, systemic vascular resistance, central venous pressure and Qs/Qt are shown in table. Spontaneous respiratory efforts slowly returned after 45 min of EIA and resulted in the improvement of gas exchange. CONCLUSION: EIA is a field ventilatory technique useful when other equipment may not be available. The airway catheter can be placed by cricothyroidotomy. EIA supports life and produces normal survivors in apneic dogs.