Nursing care and post-operative delirium in the cardiac surgery intensive care unit

Post-operative delirium is a debilitating and costly adverse event that has detrimental effects on patients’ recovery and complicates nursing care. Its numerous risk factors make the disorder seem unavoidable and unpreventable. Although pre-operative and intra-operative risk factors for delirium may not be controllable, the post-operative risk factors directly related to nursing practice are directly controllable. Practices to control pain through analgesia and sedation administration given at nurses’ prerogative may be associated with the onset of delirium in the immediate post-operative period. This study examined opioid and benzodiazepine administration given pro-re-nata (PRN) (“as needed”) by nurses to cardiac surgery patients to determine whether a relationship exists between delirium and nurses’ drug administration. One hundred twenty-two patients were assessed during the first three days following cardiac surgery for delirium with the Confusion Assessment Method for the Intensive Care Unit (CAM-ICU). Data were collected regarding potential risk factors and opioid analgesia and benzodiazepine dosages given to the patients. A retrospective chart review was conducted to determine whether the patients had a physician’s clinical assessment and diagnosis of delirium. Post-operative delirium occurred in 37.7% to 44.3% of the study sample, depending on how the cases that had positive CAM-ICU assessments and no clinical diagnoses of delirium were handled. The amount of opioid analgesia given to these patients varied widely; however, the total dosage over the 72-hour study period had no statistically significant relationship with the development of delirium (Median = 77.2 morphine equivalents (MEs) for group without delirium vs. 79.3 MEs for group with delirium; Mann-Whitney U = 1697, Z = -0.72, p = .47). The amount of Midazolam administered also varied widely. There was a statistically significant and positive relationship between the dosage of Midazolam given and the development of post-operative delirium (Median = 2.0 mg. for group without delirium vs. 4.0 mg. for group with delirium; Mann-Whitney U = 1393, Z = -2.31, p = .021). The results of this study indicate that better nursing education and changes in nurses’ practice may be required to protect patients from experiencing drug-induced post-operative delirium.Applied Science, Faculty ofNursing, School ofGraduat