Sustained Vital Sign Deviations Associated With Delirium After Abdominal Cancer Surgery

A prospective substudy published in Acta Anaesthesiologica Scandinavica examined whether severe physiological deviations were associated with postoperative delirium after major abdominal cancer surgery. Among 225 patients with complete assessments, delirium was evaluated daily using the validated 3D-CAM during the first three postoperative days. Blood pressure, respiratory rate, heart rate and peripheral oxygen saturation were continuously monitored for up to 96 hours. The primary exposure was cumulative duration of severe vital sign deviations in the 24 hours before delirium diagnosis.

Delirium occurred in 22 patients (9.8%), neurocognitive decline in 73 (32.4%), and no cognitive impairment in 130 (57.8%). Median cumulative deviation duration did not differ significantly between delirium patients and controls (204 versus 325 minutes; p = 0.63). However, sustained tachycardia, bradycardia and bradypnea episodes were more frequent during the 24 hours before delirium diagnosis (all p < 0.001). During the subsequent 24 hours, sustained tachypnea, desaturation, tachycardia and hypertension episodes were also more frequent than in controls (all p ≤ 0.005).

These associations suggest that patterns of sustained physiological disturbance may help identify patients at risk, rather than total deviation duration alone. However, this observational secondary analysis included only 22 delirium cases and does not establish causality or a validated prediction strategy. Whether responding to monitoring signals reduces delirium was not tested. Full text was unavailable for this assessment.