Evaluation of Prevalence and Effect of Hypophosphatemia on Postoperative Outcomes in Open Heart Surgeries

Background: Hypophosphatemia is a common yet under-recognized complication following open-heart surgery, potentially impacting postoperative outcomes. Despite its reported association with prolonged mechanical ventilation (MV), ICU stay, and increased morbidity, its incidence and effects remain inconsistently described.Objectives: To establish the incidence of postoperative hypophosphatemia and assess its impact on MV duration, ICU stay, cardioactive drug support, arrhythmia, and mortality.Methods: A prospective case-control study was performed on 100 cases admitted to the Cardiac Surgery ICU after elective open-heart surgery at Benha University Hospitals. Patients were categorized into hypophosphatemic and normophosphatemic groups. Perioperative parameters, laboratory findings, and clinical outcomes were analyzed.Results: Postoperative hypophosphatemia incidence was 40% immediately after surgery and 50% on day one. The hypophosphatemic group had significantly longer ventilation (16.78±3.85 vs. 5.9±2.87 hrs., p<0.001), ICU stay (4.53±1.15 vs. 2.22±0.94 days, p<0.001), hospital stay (7.4±1.65 vs. 5.25±1.2 days, p<0.001), and drain duration (41.43±13.07 vs. 28.98±9.2 hrs., p<0.001). IABP use (15% vs. 0%, p=0.002), re-intubation (12.5% vs. 0%, p=0.005), and arrhythmia (10% vs. 0%, p=0.021) were significantly higher. Mortality was higher in hypophosphatemic patients (7.5% vs. 1.67%, p=0.144), though not statistically significant.Conclusion: Postoperative hypophosphatemia is common in open-heart surgery and is associated with prolonged ICU stay, MV, and increased morbidity. Early identification and management may improve patient outcomes.