Prevalence and risk factors for hypokalemia in patients scheduled for laparoscopic colorectal resection and its association with post-operative recovery

BACKGROUND: Perioperative serum potassium levels are closely associated with postoperative clinical outcomes after gastrointestinal surgery. The aim of our retrospective study was to identify the prevalence and risk factors for preoperative hypokalemia (before pneumoperitoneum) and to evaluate the influence of preoperative hypokalemia on the recovery of postoperative gastrointestinal function. METHODS: In this retrospective study, patients scheduled for laparoscopic colorectal resection from November 11 2014 to October 20 2016, were considered for inclusion. A blood potassium level between 3.5 and 5.5 mmol/L was defined as normal, with levels between 3.0 to 3.5 mmol/L, 2.5 to 3.0 mmol/L and < 2.5 mmol/L considered as slight, moderate, and severe level of hypokalemia. The factors including age, gender, ASA grade, BMI, hypertension, diabetes, anti-hypertension drugs, lactose oral soluble, oral cathartics, oral cathartics, cathartic enemas, and blood potassium level before gastrointestinal preparation which might be associated with blood potassium level before pneumoperitoneum were analysed. The time to postoperative first flatus (FFL) and first feces (FFE) was compared between patients with and without hypokalemia. RESULTS: The final analysis was based on the data of 108 patients. Hypokalemia was identified in 70.37% patients, with the following distribution of blood potassium levels before pneumoperitoneum: slight, 49 (45.37%) patients; moderate, 23 (21.30%); and severe, 4 (3.70%) patients. Hypokalemia was significantly associated with hypertension and the use of ≥2 types of oral cathartics for preoperative gastrointestinal preparation. With treatment, potassium levels recovered to normal levels in all patients within 48 h postoperatively. Hypokalemia was associated with a longer postoperative time to first feces, compared to patients with a normal potassium level before pneumoperitoneum. CONCLUSIONS: Our findings underlie the importance of early monitoring and management of serum potassium levels in these patients.