Association of Pain With Atrial Fibrillation and Delirium After Cardiac Surgery: A DECADE Sub-Study

The authors aimed to evaluate the effects of postoperative pain on the incidence of atrial fibrillation and delirium in patients having surgery with cardiopulmonary bypass (CPB).

Post hoc analysis of the (An investigator-initiated, multicentre, double-blind trial (ClinicalTrials NCT02004613) (DECADE)), a randomized, placebo-controlled trial.

Tertiary, academic hospital.

Six hundred five adults from the DECADE enrolled at Cleveland Clinic Main Campus, who had had surgery with CPB.

Dexmedetomidine versus placebo started before surgical incision and postoperatively was maintained until 24 hours.

Primary outcomes were atrial fibrillation, diagnosed by clinicians in the intensive care unit (ICU), presence of delirium assessed with the Confusion Assessment Method for the ICU, data on pain scores, and opioid consumption, occurring between ICU admission and the earlier of postoperative day five or hospital discharge.

Postoperative pain levels were similar among patients with or without atrial fibrillation. Two hundred six (34%) patients had atrial fibrillation and ninety-two (15%) had delirium before hospital discharge within the first five postoperative days. The risk of atrial fibrillation was not significantly different between groups (hazard ratio: 1.09; 97.5% confidence interval [CI]: 0.99, 1.20, p = 0.039); there were no associations between postoperative pain and the risk of postoperative delirium (hazard ratio: 0.96; 97.5% CI: 0.84-1.11; p = 0.57). Postoperative opioid consumption was neither significantly associated with postoperative atrial fibrillation nor delirium.

Atrial fibrillation and delirium was not associated with pain after cardiac surgery. Opioid use was not associated with atrial fibrillation and delirium. Because both atrial fibrillation and delirium have a multifactorial nature, further studies should be focused on other plausible mechanisms.