Postoperative Delirium and Its Risk Factors in Elderly Patients Undergoing Heart Valve Surgery

Abstract

Objective: To investigate the incidence rate and risk factors of postoperative delirium in elder patients who were undergoing heart valve surgery.

Study Design: This observational prospective study

Place and Duration of Study: This study was conducted at the Chaudhary Pervaiz Elahi Institute of Cardiology, Multan from December 2022 to May 2023.

Methods: Patients of age above 18 years and admitted for elective valvular surgery were included in the study. The CAM-ICU was used as the diagnostic tool to evaluate delirium after surgery, applicable to both mechanically ventilated and extubated patients. This assessment tool involves four steps: (1) identifying fluctuating mental state, (2) reduced attention level (3) assessing for disoriented thinking, and (4) detecting altered mental condition.

Results: Among 230, 52 patients (22.6%) developed delirium, while 178 patients (77.4%) did not. The mean cardiopulmonary bypass (CPB) time was prolong in patients with delirium (116.42±8.99 minutes) compared to the non-delirium group (97.03±8.24 minutes) (p<0.001). Conversely, the mean aortic clamp time was shorter in the delirium group (61.62±4.51 minutes) compared to the non-delirium group (86.54±8.92 minutes) (p<0.001). Additionally, the mean ventilator time was significantly longer in the delirium group (3.54±0.64 days) compared to the non-delirium group (1.56±0.54 days) (p<0.001).

Conclusion: Delirium in post-operative period was found in 22.6% patients after open heart valvular surgery with elderly patients were identified as non-modifiable risk factor and modifiable risk factors include ventilation time and cardiopulmonary bypass time.