PHYSIOLOGICAL VARIABLES AND FLUID RESUSCITATION IN THE POSTOPERATIVE INTENSIVE-CARE UNIT PATIENT

Objective: To examine how critical surgical illness and its management alter some of the biochemical, physiologic, and hematologic parameters commonly used to monitor postoperative, critically ill patients. Design: Prospective survey of 150 patients over 3 months. Setting. University hospital surgical intensive care unit. Patients. A total of 150 consecutive adult patients admitted to the surgery-anesthesiology intensive care unit. Materials and Methods: The effects of surgery on serum albumin and total protein concentrations, and lymphocyte counts were investigated. This investigation was done by comparing the values before surgery with those values after surgery and by also comparing what happened after different types of surgery. Interventions: None. Measurements and Main Results: After surgery, decreases in serum albumin concentrations were significantly related to the estimated blood loss and acute gain in body weight from intravenous fluid resuscitation. The decreases in serum albumin and total protein concentrations were greater after elective abdominal surgery than after elective thoracic surgery. Total lymphocyte counts were significantly (<1000 cells/mm3) reduced only in patients undergoing abdominal surgery. Conclusions: Serum albumin and total protein concentrations and total lymphocyte counts were significantly reduced by surgical injury, with significantly greater decreases seen after abdominal than thoracic surgery. These decreases were caused, in large part, by the volume of intravenous fluid used in resuscitation and blood loss. The changes in these variables are thus dependent on the type of surgical stress and the perioperative fluid therapy.