Acid base abnormalities are more common in post operative patients getting admitted to critical care after major surgeries. But the outcome of these patients were considered worse in patients having metabolic acidosis which leads to prolonged ICU stay and organ failure. Hence we studied the incidence, effects and management of metabolic acidosis in postoperative patients and correlation of mortality & ICU stay in association with Sequential Organ Failure Assessment (SOFA) score.

A prospective observational study done on all postoperative patients who underwent non-cardiac surgeries under general or regional anaesthesia. The arterial blood gases taken immediately on arrival to critical care were analysed along with SOFA score. Primary outcome of the study is to find the incidence of metabolic acidosis and length of stay in patients in correlation with SOFA score on admission. Secondary outcome was to study the post-operative ventilator requirement, electrolyte abnormality and mortality associated with metabolic acidosis.

Total 102 postoperative patients were analysed, out of which 45 patients had acidemia(ph<7.35) and 7 patients had alkalemia(ph>7.45). In 45 acidemic patients, 40 patients had metabolic acidosis & 5 patients had respiratory acidosis. Patients with metabolic acidosis and normal Ph were compared. 66% of emergency and 36% of elective surgery patients had metabolic acidosis. They had significantly increased mean length of stay of 6.3 days with median SOFA score of 4(p<0.001).

Postoperative metabolic acidosis is associated with significant increase in length of stay in ICU and mortality with increased requirement of mechanical ventilation, inotropic support.