Sathu T. S, Jeji G, Sansho E. U
BACKGROUND Metabolic acidosis is proven complication of major surgery, but very less significance is given to it. Metabolic acidosis has a significant effect in postoperative recovery and morbidity of patients undergoing major surgery. Metabolic acidosis has a say in proper functioning of cardiovascular, renal and pulmonary system, added to severe stress full condition related to postoperative period, it bring about major shift in the speedy recovery of patient. It becomes significantly important that metabolic acidosis in diagnosed as early as possible and corrective measures are taken immediately. MATERIALS AND METHODS Study design is a prospective observational study. 109 patients who underwent elective and emergency surgeries in the department of General Surgery, Govt. Medical College Kottayam was studied for a period of 3 months (2016). On arrival of the patient, a detailed history of the patient was taken, along with emphasis to the multiple factors in the history which could be contributory to postoperative metabolic acidosis such as diabetic status, drug history, history of respiratory, cardiac and renal status. Basic preoperative laboratory investigation was carried out and its values were recorded. A preoperative arterial blood gas analysis (ABG) of the patient was done before patient was taken for surgery, values of which were recorded and analysed to rule out existing acidotic status of patient, if the patient is already having metabolic acidosis he was excluded from the study. A second ABG was sent at 2 hours after induction of anaesthesia, values of which was recorded, along with the values of intraoperative fluids, preoperative Hb, duration of surgery, type of surgery, blood transfusion and colloid administration given during the time of anaesthesia. A third ABG was sent within six hours of completion of surgery and the values analysed, with due notes on postoperative care done and the days of ICU stay, for analysis and comparison. RESULTS Duration of surgery was significantly related to incidence of both intraoperative and postoperative metabolic acidosis. When cross tabulation was done between operative duration and intra operative metabolic acidosis, it was found that 14(87.5%) subjects of total 16 who had duration of greater than 5 hrs had metabolic acidosis. 10 (62.5%) individuals of operative duration 2.01-3 hrs., 28 (73.7%) individuals from 3.01-4 hrs. group and 37 (94.9%) individuals from 4.01-5 hrs duration group were found to have intra operative metabolic acidosis. On doing an independent t test for calculating the significance of each of total crystalloid, normal saline and ringer lactate it was found that ringer lactate had a significant relationship with postoperative metabolic acidosis, indicated by a p value of 0.030, while normal saline had no significant relation to postoperative metabolic acidosis. Still it is interesting to note that total crystalloid administered had a significant relation to postoperative metabolic acidosis indicated by a p value of 0.047. Colloid administration was also found to have a positive relationship with both intra operative (p value of 0.019) and postoperative metabolic acidosis (p value of 0.009). CONCLUSION This study stresses the need of doing an intra operative blood gas analysis, in all prolonged surgeries, to analyse and begin corrective measures intra operatively itself, such that patient has least postoperative morbidity and speedy recovery.
