A Systematic Review of Strategies for Preventing Delirium in Patients Undergoing Vascular Surgery

Abstract

Elderly patients undergoing vascular surgery are at a risk of developing postoperative delirium, which is associated with high mortality. Delirium prevention is difficult and is investigated in surgical patients from various specialisms, but little is known about delirium prevention in vascular surgery. For this reason we performed a systematic review on strategies for delirium prevention in patients undergoing elective surgery for peripheral arterial disease or for an aneurysm of the abdominal aorta. This systematic review included studies describing strategies for preventing delirium in patients undergoing elective surgery for peripheral arterial disease or for an aneurysm of the abdominal aorta. The search was conducted using the keywords 'vascular surgery,' 'prevention,' and 'delirium' and was last run on October 21, 2021 in the electronic databases PubMed, MEDLINE, Embase, Web of Science, the Cochrane library, and Emcare. Risk of bias was assessed using the Cochrane risk of bias tool for randomized controlled trials and the ROBINS-1 tool for observational studies. Four studies including 565 patients were included in the systematic review. A significant decrease in the incidence of delirium was reported by a study investigating the effect of comprehensive geriatric assessments within patients undergoing surgery for an aneurysm of the abdominal aorta or lower limb bypass surgery (24% in the control group vs. 11% in the intervention group, P=0.018) and in the total group of a study evaluating the effect of outpatient clinic multimodal prehabilitation for patients with an aneurysm of the abdominal aorta (11.7% in the control group vs. 8.2% in the intervention group, P=0.043, Odds Ratio=0.56). A nonsignificant decrease in delirium incidence was described for patients receiving a multidisciplinary quality improvement at the vascular surgical ward (21.4% in the control group vs. 14.6% in the intervention group, P=0.17). The study concerning the impact of the type of anesthesia on delirium in 11 older vascular surgical patients, of which 3 developed delirium, did not differentiate between the different types of anesthesia the patients received. Despite the high and continuous increasing incidence of delirium in the growing elderly vascular population, little is known about effective preventive strategies. An approach to address multiple risk factors simultaneously seems to be promising in delirium prevention, whether through multimodal prehabilitation or comprehensive geriatric assessments. Several strategies including prehabilitation programs have been proven to be successful in other types of surgery and more research is required to evaluate effective preventive strategies and prehabilitation programs in vascular surgical patients.