Extracorporeal oxygenation in puppies and in newborn and fetal lambs

Abstract

1. Extracorporeal blood oxygenation was achieved by the membrane oxygenator described by Peirce and Galletti in 6 puppies, 1 to 4 months old, 7 near and at term fetal lambs, and 4 4-hour- to 4-day-old newborn lambs. The mean weight of the animals was 3,310 grams. Mean duration of extracorporeal assistance was 3 hours and 18 minutes. Mean extracorporeal blood flow rate was 104 ml. per minute per kilogram. Partial heart-lung bypass was achieved by right atrial venous drainage and carotid arterial infusion.2. None of the fetal animals breathed during the perfusion period; breathing in the newborn animals ceased at the beginning of the perfusion. The puppies were asphyxiated for different periods during extracorporeal circulation.3. Fourteen animals (out of 17) gained less than 4 per cent of their initial body weight.4. Satisfactory artificial oxygenation could be achieved but CO2 release was poor with the 0.5 mil thick cast Teflon membranes used. No problems of metabolic acidosis or electrolytic imbalance were encountered.5. Over-all survival rate was low (517) but higher (36) in puppies than in fetal or newborn lambs (211). The role of species, age, patency of shunts, anesthesia of the ewe, fetal anoxia before perfusion, coagulation defects, and endotoxic shock is discussed.