Background: In the current era of surgical practice, conventional cardiac surgery still occupies the main bulk of operations, but its postoperative complications are numerous and can lead to morbidity and mortality. Cardiopulmonary bypass time is a major risk factor in cardiac surgery. Several surgeons underestimate the importance of reducing bypass time and its effect on patient outcomes, and there is no known cutoff time for bypass that is associated with higher complications.
Aim of the work: To assess the correlation between bypass time and patient outcomes and clarify the relevant period or a cutoff time for safe cardiopulmonary bypass.
Patients and Methods: A retrospective single-center comparative study of 450 cases of conventional cardiac surgery, 300 valve surgeries and 150 coronary bypass surgeries in the Cardiothoracic Surgery Department, Tanta University between January 2018 and January 2023, categorized into 3 groups: Group A: bypass time less than 60 minutes, Group B: bypass time from 60 to 120 minutes, Group C: bypass time more than 120 minutes.
Results: There was a significant difference between the 3 groups in favor of Group A with the least bypass time regarding post-operative renal complications [p-value = 0.002], respiratory complications [p-value = 0.013], neurologic complications [p-value = 0.001], multiple blood transfusions [p-value = 0.04], infections [p-value = 0.04] and mortality [p-value = 0-001]. However, no significant difference regarding demographic data, comorbidities, creatinine level and ejection fraction.
Conclusion:  Bypass time is a major predictor and is proportionally related to morbidity and mortality in cardiac surgery; a bypass time up to 60 minutes is the safest with the least morbidity and mortality.