Moderate hypercapnia may not contribute to postoperative delirium in patients undergoing bronchoscopic intervention

Abstract

This study aimed to investigate the risk factors and whether acute hypercapnia contributes to postoperative delirium (POD) during bronchoscopic intervention under general anesthesia or deep sedation. A prospective study was conducted with 119 consecutive patients who had undergone bronchoscopic intervention between February 2016 and December 2016 at the Emergency General Hospital. Twenty-eight patients (23.8%) were diagnosed with POD. The patients were divided into 2 groups: the POD (n = 28) and the control group (n = 91). The mean age of the POD group was higher than that of the control group ( P < .01). All the blood gas values, PaCO 2 ( P < .01), PaO 2 ( P < .01), and PH ( P < .01), were significantly different. Multivariate analyses revealed that age ( P < .01), operation duration ( P = .01), and PO 2 ( P = .01) were independent predictive factors of POD, while hypercapnia ( P = .54) was established as not being a predictive factor of POD. Age, operation duration, and PO 2 were determined as independent predictive factors of POD, whereas moderate hypercapnia is not likely to contribute to POD in patients undergoing bronchoscopic intervention. Clinical Trial Registration Identifier: ChiCTR-POC-15007483.

Intraoperative low tidal volume ventilation and the risk of ICD-10 coded delirium and the use for antipsychotic medications

“…PaCO 2 is a fundamental determinant of cerebral blood flow, cerebral metabolism and intracranial pressure, which suggests a biologically plausible mechanism for an effect on cognitive function [ 2 , 3 ]. However, to the date, studies assessing the association between hypercapnia and POD have yielded inconsistent and conflicting results [ 8 – 12 ]. Furthermore a recent observational study suggested that avoidance of end-tidal hypocapnia may be associated with a reduced risk of POD [ 26 ].…”

“…The effect of an increased PaCO 2 on neurologic function is likely complex and both favourable and unfavourable neurologic effects have been described in different clinical settings [ 2 – 7 ]. Similarly, the association of increased intraoperative PaCO 2 levels and the incidence of post-operative delirium (POD) is unclear, and previous small observational studies have yielded mixed results [ 8 – 12 ]. Given that POD is common, associated with poor outcomes and may be partly preventable, identifying strategies that reduce its incidence by targeting potential modifiable risk factors such as PaCO 2 appears desirable [ 13 – 17 ].…”

High frequency jet ventilation through mask contributes to oxygen therapy among patients undergoing bronchoscopic intervention under deep sedation

“…Pearson analysis showed no important factors affecting PaCO 2 and certainly no independent factors, either. Mild hypercapnia may not cause brain injury and only worsen the condition of the brain when PaCO 2 is above 100 mmHg [ 8 , 18 , 19 ]. Thus anesthesiologists did not provide any treatment when the PaCO 2 was a little above 50 mmHg.…”

High frequency jet ventilation through mask contribute to oxygen therapy in patients undergoing bronchoscopic intervention under deep sedation

“…Pearson analysis showed that there were no important factors affecting PaCO 2 , certainly no independent factors either. It had been reported that mild hypercapnia may not cause brain injury and worsen the brain's condition only when PaCO 2 was above 100mmHg 8,18,19 . This is the reason why anesthesiologists didn't do any treatment when PaCO 2 was a little above 50 mmHg.…”