Incidence of Postoperative Acid-Base Disturbances in Abdominal Surgery

Respiratory and blood pressure changes as well as fluid administration alter the acid-base balance during the perioperative period which may cause consciousness disturbance and additional hemodynamic disorders. The aim of this study was to identify frequent postoperative acid-base disturbances in order to control postoperative complications. This prospective, observational study design was used on patients who underwent abdominal surgery during a six-month period. Gasometry was performed immediately after the patients’ admittion to ICU and six and 12 hours postoperatively. SPSS v13 software was used, and P 213 patients (123 male and 90 female) aged 14-85 years (51.7± 22.4) were evaluated. During admission, PH and PaCO2 were (7.29±0.13) and (38.3±11.9), respectively; however, although PH increased gradually (P=0.001), PaCO2 was reduced (P=0.03). Bicarbonate and base excess had opposite effects; bicarbonate initially decreased but increased after 12 hours (P=0.001), whereas base excess initially increased (-6.3±11.6) and then decreased gradually (P=0.003). The arterial oxygen pressure was reduced for 22.5% of the patients throughout the admission period, and this did not significantly change (P=0.57). According to the results, in admission, 65.7% had metabolic acidosis, but metabolic alkalosis was the least. Gradually, metabolic acidosis was modified, but metabolic alkalosis increased. Intraoperative hypotension and fluid infusion may be the main factors of early metabolic acidosis and control of hypotension, or correction of acidosis may increase metabolic alkalosis.