[Study on changes in extravascular lung water during early postoperative periods in thoracic esophageal cancer--with...

Twenty-seven patients with esophageal cancer received an intrathoracic esophagectomy, lymphadenectomy and esophageal reconstruction performed in one stage. They were analyzed for respiratory and hemodynamic function parameters and also observed for the time course of extravascular lung water (EVLW), water balance, renal function as well as colloid osmotic pressure (COP) of plasma. And they were clarified the pathogenetic mechanism of post-operative pulmonary complications mainly from the aspects of pathophysiology of pulmonary edema and functional interrelationship of organs. Two groups of patients, i.e. those undergoing extended lymphadenectomy (particularly for lymph nodes of both sides of neck and upper mediastinum) and those of old age (70 years or above), were investigated for eventual characteristic features of postoperative changes in the parameters mentioned above. In the group of patients with postoperative pulmonary complications, a significant negative correlation was noted to exist between the plasma colloid osmotic pressure-pulmonary artery wedge pressure (COP-PAW) gradient and EVLW and between the former parameter and postoperative renal function (p less than 0.01). A postoperative lowering of renal function observed in the group with postoperative pulmonary complications was due mainly to depressed left ventricular function immediately following operation and assumed to play a significant role in the production of pulmonary edema as a hydrostatic factor subject to the Starling's low. In the group undergoing extended lymphadenectomy, extensive lymph node dissection reduced plasma colloid osmotic pressure. This reduction was thought to bring about a diminution of COP-PAW gradient, produce a transient depression of left ventricular function and augmentation of pulmonary edema, and to stimulate the formation of intrapulmonary shunting. In the old age group, their and renal function depressed immediately after operation because of advanced age. And for the maintenance of cardiac function massive water intake was required. They led to retention of water and thereby played a direct role in the causation of increase in EVLW and in intrapulmonary shunt. All these observations point to the necessity of initiating carefully planned management early in the postoperative period that takes these pathophysiologic features well into account.