The effects of immersion and temperature on respiration in newborn lambs

The effects of immersion on respiration of term lambs during the perinatal period were studied under various conditions. After consistent breathing had developed in the newborn animal, immersion of the entire animal, immersion of its head, or introduction of fluid retrogradely into the trachea produced very marked respiratory depression as determined by a pneumotachometer attached to a trachial airway. Less marked, but still significant, respiratory depression was noted in animals subjected to snout immersion and to immersion with the head kept above the water bath. In this latter group, warm water depressed breathing more than cool water. The inhibitory effect of immersion on the initiation of breathing was shown by lack of survival of intubated lambs delivered into a water bath.