Electrolyte and Acid-base Disturbances in Emergency High-risk Abdominal Surgery, A Retrospective Study

Abstract BACKGROUNDPatients undergoing emergency high-risk abdominal surgery potentially suffer from both systemic dehydration and hypovolaemia. Data on the prevalence and clinical impact of electrolyte disturbances in this patient group, specifically the potential differences in patients with intestinal obstruction (IO) versus perforated viscus (PV) is lacking. METHODSIn this retrospective single center cohort study, adult patients undergoing emergency high-risk abdominal surgery in a standardized perioperative pathway were included. Electrolyte and arterial blood gas analysis were measured prior to and just after surgery. Prevalence and clinical impact of electrolyte disturbances were assessed. RESULTSA total of 354 patients were included in the study. Acid-base and electrolyte disturbances had a high incidence in both groups with preoperative alkalemia dominating preoperatively, significantly more prevalent in IO (45 vs.32%, p<.001), and acidosis being most pronounced postoperatively in PV (49 vs. 28%, p<.0001). Preoperative hypochloraemia and hypokalemia were more prevalent in the IO group (34 vs 20 % and 37 vs 25 % respectively). Hyponatremia was highly prevalent in both IO and PV. Of the electrolyte and acid-base disturbances pre- and postoperative hypochloremia were the only ones independently associated with day-30 postoperative major complications and/or death in patients with IO, OR 2.87 (1.35, 6.23) p= 0.006 and OR 6.86 (1.71, 32.2) p= 0.009 respectively. Hypochloremic patients presented with reduced long-term survival as compared with the normo- and hyperchloremic patients, with postoperative hypochloremia having the most pronounced association (p<0.05). Neither plasma sodium nor potassium showed association with outcome.CONCLUSIONThese observations suggest that both acute high risk abdominal patient have frequent preoperative alkalosis shifting to postoperative acidosis, and that both pre- and postoperative hypochloremia are independently associated with both impaired short- and long-term outcome in patients with intestinal obstruction, which potential implications for the choice of resuscitations fluids. Research on pathophysiology and treatment strategies for electrolyte disturbances are needed in patients undergoing emergency high- risk abdominal surgery.