Electrolyte disturbances frequently occur after cardiac surgery involving cardiopulmonary bypass (CPB), yet their contribution to postoperative complications remains incompletely defined. A retrospective descriptive analysis published in the Journal of Intensive Medicine evaluated associations between perioperative electrolyte abnormalities and clinical outcomes in adult patients undergoing open-heart surgery.

The study included 1392 patients who underwent elective coronary artery bypass grafting (CABG), valve procedures, or aortic repair at a single center between January 2017 and August 2023. Serum sodium, potassium, magnesium, and phosphorus levels were measured in the immediate postoperative period. 

Outcomes assessed included postoperative atrial fibrillation (POAF), atelectasis, and pleural effusion, defined using clinical and imaging criteria. Statistical analyses incorporated Chi-squared testing, independent t-tests, and logistic regression models.

POAF was the most frequent complication, occurring in 249 patients (17.9%), while pulmonary complications were reported in 124 patients (8.9%). Hypernatremia was associated with higher complication rates (24% vs. 8%; odds ratio [OR]=3.500; 95% confidence interval [CI]: 1.673–7.323; P<0.001), whereas hyponatremia showed no association. 

Hyperkalemia was significantly associated with respiratory complications (OR=2.113; 95% CI: 1.055–4.230; P=0.035), while hypokalemia was not. Hyperphosphatemia independently increased the risk of atelectasis and pleural effusion (OR=1.523; 95% CI: 1.015–2.284; P=0.042).

Hypermagnesemia was also linked to higher pulmonary complication rates (12.4% vs. 6.5%; OR=1.636; 95% CI: 1.100–2.434; P=0.015). No significant associations were identified between electrolyte imbalances and POAF, although hyperphosphatemia showed borderline significance (P=0.051).

Electrolyte abnormalities were associated with postoperative pulmonary complications following CPB surgery. Associations with POAF were not consistently observed.