Objective: To investigate the perioperative electrolyte imbalance in patients undergoing gastrointestinal surgery.
Methods: Retrospective case analysis was used in this study. Patients who underwent gastrointestinal surgery under general anesthesia at the Sixth Affiliated Hospital of Sun Yat-sen University from January to April 2018 were selected through electronic medical records system. Blood gas analysis during surgery must be carried out in the enrolled patients. Patients with excessive fluid infusion, critical conditions or patients who had been enrolled in other clinical trials were excluded. A total of 999 patients were enrolled. The preoperative, intraoperative and postoperative concentrations of serum sodium, potassium and calcium were collected by the last biochemical examination before surgery, arterial blood gas analysis within 1 h after anesthesia and another biochemical examination within 24 hours after surgery respectively. The type and incidence of electrolyte imbalance were then analyzed, and logistic regression analysis was used to investigate the risk factors.
Results: In the 999 patients, 683 cases were male (63.9%) and 361 cases were female(36.1%), with an average age of (56.9±14.6) years old. Fifty-eight patients (5.8%) underwent emergency surgery and 941 patients (94.2%) underwent elective surgery; Sixty-two patients were treated with laxatives at least 3 times and 115 patients were treated with enema at least 3 times before operation. The incidence of hypokalemia was 49.6%(496/999) intraoperatively and decreased to 15.2%(152/999) postoperatively. No hyperkalemia cases were found. The incidence of hypocalcemia was 53.8%(537/999) intraoperatively and increased to 79.7% (796/999) postoperatively. The incidence of hypokalemia in ileus patients was 33.3%(17/51) before surgery, which was higher than that in patients with colorectal cancer [12.3%(86/703)], patients with gastric cancer [7.8%(8/104)] and patients with other gastrointestinal diseases[10.6%(15/141)] (all P<0.05). Similarly, the preoperative and intraoperative incidence of hyponatremia in ileus patients were both 15.7%(8/51), which were higher than those in patients with colorectal cancer [3.0% (21/703) and 2.3% (16/703)] and patients with gastric cancer [2.9%(3/104) and 1.9%(2/104)]. The incidence of hypocalcemia in ileus patients was 31.4%(16/51) preoperatively, which were also higher than those in patients with colorectal cancer [7.4%(52/703)] and patients with gastric cancer [8.7%(9/104)] (all P<0.05). Logistic regression analysis showed that ileus and emergency surgery were risk factors for patients with preoperative electrolyte imbalance; preoperative electrolyte imbalance was a risk factor for intraoperative electrolyte imbalance; intraoperative electrolyte imbalance was a risk factor for postoperative electrolyte imbalance; preoperative electrolyte imbalance was a risk factor for postoperative imbalance of sodium and potassium.
Conclusions: The incidence of electrolyte imbalance is high in patients undergoing gastrointestinal surgery, especially hypocalcemia and hypokalemia. It is necessary to recognize the electrolyte abnormality timely and give active intervention and correction.