Background: Pain is one of the important causes of delirium. Recent studies have reported some evidence of the appropriate effect of acetaminophen in delirium. Therefore, this study aimed to determine the effect of intravenous (IV) acetaminophen with oral acetaminophen on the incidence of delirium after cardiac surgery. Methods: This study was a double-blind randomized clinical trial. Patients with available inclusion criteria were randomly allocated into either the oral or IV acetaminophen groups. In the IV group, 1 gram of acetaminophen was administered every 8 hours after the cardiac surgery, and continued until the first 48 hours. In the oral group, 500 mg of acetaminophen was administered every 6 hours for 48 hours. In addition, both groups received morphine (PRN) for pain, and the dosage and repetition were recorded. The primary outcome was the incidence of delirium based on the Richmond Agitation Sedation Scale scale and the Confusion Assessment Method for the Intensive Care Unit (CAM-ICU). Results: There was no significant difference in pain level between the two groups ( P > 0.05). The mean dose of morphine was higher in the oral acetaminophen group, but no significant difference was observed between the two groups ( P > 0.05). There was no significant difference between the two groups in terms of delirium incidence and ICU length of stay ( P > 0.05). Conclusion: According to the results of the present study, it seems that the administration of IV and oral acetaminophen does not statistically significant effect in terms of pain intensity, surgical complications, and delirium.
Nikzad-Jamnani et al. (Wed,) studied this question.