Ince I, Chui A, Sagir A, et al. - This study was carried out to assess the effects of postoperative pain on the incidence of atrial fibrillation and delirium in patients having surgery with cardiopulmonary bypass. Researchers enrolled a total of 605 adults who had had surgery with cardiopulmonary bypass. After cardiac surgery, atrial fibrillation and delirium are not correlated with pain. There was no association between opioids and atrial fibrillation, delirium. Since both atrial fibrillation and delirium have multifactorial nature, there is a need for future trials to evaluate other plausible mechanisms.