Occurrence and clinical relevance of postoperative hypernatremia in dogs undergoing cholecystectomy

Abstract

Background: Patients undergoing cholecystectomy have not been reported previously to develop clinically relevant postoperative hypernatremia.

Objectives: Describe the frequency of postoperative hypernatremia in dogs undergoing cholecystectomy and its clinical relevance (duration of hospitalization and survival).

Animals: Thirty-seven dogs undergoing cholecystectomy at 2 private referral hospitals.

Methods: Retrospective study of dogs undergoing cholecystectomy with available preoperative and postoperative serum sodium concentrations.

Results: Postoperative hypernatremia (>150 mEq/L) was common (56%; 95% confidence interval [CI], 40%-70%) and was associated with significantly higher mortality compared to nonhypernatremic patients (52%; 95% CI, 30%-70% vs 12.5%; 95% CI, 2%-40%; P = .02). Nonsurvivors had higher mean postoperative peak serum sodium concentrations (155 mEq/L; range, 146-172) than survivors (150 mEq/L; range, 142-156; P = .01). Dogs developing hypernatremia within 6 hours after surgery had 7.7 higher odds of nonsurvival (odds ratio [OR], 7.7; 95% CI, 5.9-9.4). A delta value (serum sodium concentration on admission [T0] - serum sodium concentration 6 hours postoperatively [T2]) of ≥10 mEq/L carried 3.3 higher odds of mortality (OR, 3.3; 95% CI, 1.6-5.1). All dogs with a postoperative peak sodium concentration >160 mEq/L did not survive. Admission acute patient physiologic laboratory evaluation fast (APPLE_fast ) scores were not different between survivors and nonsurvivors or between postoperative hypernatremic and normonatremic patients. Hospitalization time was no different between hypernatremic and normonatremic patients (6 days vs 4.5 days; P = .15). Dogs with gallbladder mucocele were more likely to develop postoperative hypernatremia and have poorer outcomes.

Conclusions: Hypernatremia was a common and clinically relevant postoperative complication in dogs after cholecystectomy. Detection of hypernatremia within 6 hours after surgery may be associated with poorer outcomes.

Keywords: gallbladder; gallbladder disease; gallbladder mucocele; postoperative complication; sodium.