[Hypercapnia following major laparotomy--retrospective analysis of 50 cases]

Hypercapnia is a poorly investigated problem in the management of postoperative complications. In order to define the clinical implication of postoperative hypercapnia, hospital records of fifty patients, who had hypercapnia (PaCO2 greater than or equal to 45 torr) within 30 days after major laparotomy, were analyzed retrospectively. Patients with chronic pulmonary disease, prolonged apnea, additional thoracotomy and inadequate setting of ventilator were excluded. Results were as follows. 1. Thirty-two patients were hypercapnic before the 3rd postoperative day. These patients had various causes for hypercapnia, and clinical course and outcome were dependent on the underlying clinical problem. 2. Eighteen patients showed hypercapnia after the 4th postoperative day. In these patients, invasive infection was a common problem and 17 out of 18 patients died mainly of sepsis. 3. Sites of septic focus were mostly in the abdominal area (i.e., intraperitoneal, retroperitoneal and intrahepatic), and in most cases, hypercapnia preceded the establishment of diagnosis of septic focus or the recognition of other organ dysfunction. CO2 retention in the septic patients was due to the increased dead space ventilation by ventilation-perfusion maldistribution. Therefore, hypercapnia found after the 4th day following laparotomy seems to indicate potential intraabdominal sepsis and prompts the necessity for effective drainage.