[Follow-up of abdominal surgery by analysis of pH, p02 and pCO2 in drainage fluid].

Milieu factors such as pH, pO2, and pCO2 have previously been shown to permit reliable intraoperative discrimination of infected and non-infected peritoneal or drainage fluid. The presence of infection was associated with pH less than 7.1, pO2 less than 6.5 kPa and pCO2 greater than 8 kPa. These variables were monitored in the immediate postoperative period to quantify clinical improvement and to evaluate their potential for the early detection of infective complications. 21 patients underwent laparotomy for intraabdominal infections such as perforated appendicitis or perforated sigmoid diverticulitis. 5 were operated on for reasons other than infection. Fluid was sampled from a drainage tube every second day for a mean period of 7 days for determination of pH, pO2, and pCO2. A score ranging from 0 (normal) to 6 (severely ill) was calculated from these measurements. Specimens were obtained intraoperatively from 14 patients with documented infections and their mean score averaged 5 (range 3-6). Specimens were obtained on days 4 and 6 from 18 patients whose progress was uneventful and their mean score was 0.3 (range 0-2). 4 of these 26 patients developed postoperative infections after anastomotic breakdown, and each of their scores increased 1-2 days before the infection became clinically obvious, reaching values ranging from 3-6. In contrast, only 1 of 18 patients who made uneventful progress scored greater than 2 after day 3 (p less than 0.01). We conclude that assessment of milieu factors in peritoneal or drainage fluid permits quick and easy monitoring of the postoperative course.