Base excess and pH as predictors of outcomes in secondary peritonitis in a resource limited setting - A prospective study

Background: Estimation of the serum pH and base excess as determinants of the adequacy of resuscitation may predict the patient outcome in peritonitis. Materials, Patients and Methods: This was a prospective study conducted in University College Hospital, Ibadan, on patients from 18 years and above with diagnosis of secondary peritonitis who had exploratory laparotomy over a 4-month period (January to April 2017). The patients' biodata, pulse rate, blood pressure, and clinical diagnosis were documented. At presentation, the patients were resuscitated with intravenous normal saline and broad-spectrum antibiotics. Each patient had measurements of acid-base status, and pH analyzed at presentation and in the immediate postoperative period (within 1 h) using the I-STAT point of care device. They were followed up for 48 h after the surgery. The changes in base excess and serum pH in survivors and nonsurvivors were described at 48 h after surgery. This was statistically compared using SPSS version 20 (Chicago, IL, USA). Results: A total of 45 patients were recruited comprising 37 males and 8 female patients. The mean age was 40.86 ± 15.45 years. The mean admission base excess was −4.76 ± 5.41. The mean admission pH was 7.41 ± 0.07. There were 28 (62%) survivors and 17 (38%) mortalities. The pH on admission and base excess values and after surgery demonstrated statistical significance in survivors and nonsurvivors. Conclusion: Changes in base excess and serum pH values are plausible outcome markers in patients with peritonitis resuscitated with early goal-directed therapy.