Presurgical depressive symptom and anaesthetic requirements in patients undergoing surgery for malignant and non-malignant conditions: A prospective observational cohort study.

The incidence and magnitude of depression are rarely assessed during preanaesthetic evaluation. The shared physiological mechanisms of depression and anaesthetic drugs are likely to alter the pharmacodynamics of propofol. Therefore, the study aimed to evaluate the burden of presurgical depression and its effect on propofol consumption during anaesthesia. This prospective, observational, cross-sectional, analytical study included adult patients (> 18 years) undergoing surgery. During the preoperative period, depressive symptoms were evaluated by the psychiatrist on 9-point Patient Health Questionnaire-9 (PHQ-9). The propofol requirements were recorded during anaesthesia and compared with those for patients without depression. One hundred and seventy-four patients (87 patients each with and without cancer) underwent presurgical evaluation. The prevalence of depression (>4 Patient Health Questionnaire-9) and moderate to severe depression (>9 PHQ-9) among patients with cancer was 58.6% and 35.6%, respectively. The prevalence of depression (>4 PHQ-9) and moderate to severe depression (>9 PHQ-9) among patients without cancer was 18.4% and 3.4%, respectively. In the cancer group, propofol requirement was significantly lower (114.7 ± 22.9mg vs. 126.4 ± 24.3mg; p = 0.025) in patients with depression than that in those without depression. In conclusion, the burden of depression during the preanaesthetic period among patients with cancer is substantial, and depression reduces propofol requirement during surgery.