High score literature reading. There is a dose-dependent relationship between intraoperative hypoxemia or hypocapnia and postoperative delirium in elderly patients

Dose-dependent relationship between intra-procedural hypoxaemia or hypocapnia and postoperative delirium in older patients

There is a dose-dependent relationship between intraoperative hypoxemia or hypocapnia and postoperative delirium in elderly patients

By Dani & Miao & Cats

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Background: Previous studies have shown that impaired cerebral perfusion is associated with
postoperative cognitive impairment.
We investigated the association
of intraoperative hypoxaemia and hypocapnia with postoperative delirium.

Methods: In this hospital retrospective study, we included patients
aged over 60 years who received anesthesia for surgical or interventional procedures from 2009 to 2020.
The main observation indicators were intraoperative persistent hypoxia, defined as oxygen saturation less than 90% for more than 2 minutes, and hypocapnia, defined as small exhalation carbon dioxide equal to 25mmHg for more than 5min
.
The primary outcome was a 7-day postoperative delirium assessment
.

Results: A total of 71717 patients
were enrolled.
Postoperative delirium
occurred in 1702 (2.
4%).
Of the 42,894 patients with general anesthesia, 2532 patients (3.
5%) developed hypoxemia
.
Hypocapnia
occurred in 532 (1.
2%).
Hypoxemia (ORadj1/4 1.
71; 95% CI, 1.
40-2.
07; P<0.
001) and hypocapnia (ORadj1/4 1.
77; 95% CI, 1.
30-2.
41; P<0.
001) is associated with
postoperative delirium.
The correlation between the two depends on the amplitude and varies with duration (ORadj1/41.
03; 95% CI, 1.
02-1.
04; P<0.
001 ，ORadj¼1.
01; 95% CI, 1.
00-1.
01; P1/40.
005, calculated as a change per minute for the maximum time period).

Hypercapnia was not associated with postoperative delirium (ORadj1/41.
24; 95% CI, 0.
90-1.
71; P¼0.
181)
。

Conclusion: Continuous hypoxemia and hypocapnia during surgery are associated
with the risk of postoperative delirium.
These findings support the maintenance of normal ventilation to prevent postoperative neurocognitive dysfunction
.

Figure&Table

Flow sheet

Baseline characteristics

The duration of hypoxemia predicts postoperative delirium

Duration of hypocapnia predicts postoperative delirium

Original link: doi: 10.
1016/j.
bja.
2022.
08.
032