PRESERVATION OF ALVEOLAR EPITHELIAL FLUID TRANSPORT MECHANISMS IN REWARMED HUMAN LUNG AFTER SEVERE HYPOTHERMIA

Although hypothermia abolishes alveolar fluid clearance in the in situ goat lung and in the ex vivo human lung, it is unknown whether alveol ar fluid clearance resumes in lungs that are rewarmed after severe hyp othermia. An isosmolar albumin solution was instilled into resected hu man lungs that were rewarmed to 37 degrees C after hypothermia (7 +/- 3 degrees C), and then alveolar fluid clearance was measured by the co ncentration of albumin in the alveolar fluid sample after 4 h. In cont rol experiments in lungs that had not been cooled and rewarmed, alveol ar fluid clearance was 11 +/- 2% over 4 h. In separate experiments, hy pothermia completely abolished alveolar fluid clearance. However, alve olar fluid clearance resumed to a normal level of 12 +/- 1% over 4 h i n the lungs that were rewarmed after hypothermia. Amiloride decreased alveolar fluid clearance by 47% in the rewarmed lungs. Terbutaline inc reased alveolar fluid clearance by nearly 300% in 2-h experiments in t he rewarmed lungs (P < 0.06). The results of this study indicate that alveolar sodium-channel transport mechanisms are preserved in resected human lungs that are exposed to rewarming after hypothermia.