Are chemotherapy and radiotherapy risk factors for post-operative delirium in elderly cancer patients undergoing elective surgery? Observational study in two tertiary university hospitals
Many elderly cancer patients undergo surgery. Age and impaired physical status are risk factors for post-operative delirium (POD), a cognitive disorder with disorientation, hallucinations and disturbance of vigilance. Aim of this study was to evaluate the independent association of pre-operative chemotherapy and radiotherapy on POD in ≥ 65 year old cancer patients.
METHODS:
Between 02- 2011 and 09-2012 and after ethical committee approval and written informed consent the study was conducted in 2 tertiary university hospitals in Germany. Patients were categorized according to the American Society of Anesthesiologists physical status classification system (ASA PS) score. Post-operatively patients were screened for POD using the Nursing Delirium Screening Scale, Nu-DESC respectively the Confusion Assessment Method for the ICU (CAM-ICU) within 7 days post-operative. Multivariate analysis was by logistic regression analysis.
RESULTS: Overall 658 patients (mean age 71.8 years, 68.4% males) with prostate cancers (38.8%), ovarian cancers (13.7%), other cancers of the genito-urinary tract (16.0%), upper gastroinstestinal tract (21.1%) and colorectal cancers (10.5%) were included. Preoperatively 77 patients (11.7%) had received chemotherapy and 27 (4.1%) radiotherapy. Within the first 7 days after operation 61 patients (9.3%) developed POD. In multivariate analysis adjusted for age, gender, ASA PS score and tumor site, study participants after preoperative chemotherapy were at decreased risk for POD, Odds Ratio = 0.23 (95%-confidence interval (0.07 – 0.73)), p = 0.012 while study participants after radiotherapy showed a tendency for increased POD: OR = 3.1 (95%-CI (0.9 – 10.3)), p = 0.07.
CONCLUSIONS:
Pre-operative chemotherapy in cancer patients is associated with post-operative delirium.