Purpose:
The purpose of this project is to determine if delirium assessment results vary during a 24-hour period. This project determined if there was a specific time of day when patients are more likely to screen positive for delirium.
Significance:
The results of this study can be used to determine when to assess for delirium. Discovering whether delirium assessments vary during the day can help one decide how often assessments should be performed.
Design:
Multiple risk factors and etiologies exist and vary among critically ill patients. According to the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition (DSM-IV) criteria, delirium has an acute onset or fluctuates during the course of a day. As delirium fluctuates, assessments at different times of the day may yield conflicting results. The etiologies may also vary throughout the day, leading to different assessment results. Therefore, identification of delirium may vary depending on when the assessment is performed.
Methods:
The DSM-IV criteria is the gold standard for assessing delirium; however only trained professionals can perform the DSM-IV assessment. The DSM-IV assessment takes around 30 minutes to complete, and the participant must be able to verbalize answers. There are other assessment tools for delirium, but not all of them can be applied in the intensive care unit. The Confusion Assessment Method for the Intensive Care Unit (CAM-ICU) was selected for its usefulness in the critically ill population. The tool is easy to use and takes an average of 2 minutes to complete. Nurses can perform the assessment with little training. The CAM-ICU is based on the DSM-IV definition of delirium and has high specificity and sensitivity in ventilated as well as nonventilated patients. Ely et al (2001) demonstrated reliability and validity of the CAM-ICU. The CAM-ICU has an interrater reliability of k = .95. Validity was determined with a sensitivity of 95% to 100% and a specificity of 89% to 93%. The CAM-ICU has 4 features: (1) change in mental status from baseline or fluctuating course, (2) inattention, (3) disorganized thinking, and (4) altered level of consciousness. Delirium is present when features 1 and 2 are present, along with either feature 3 or 4. Institutional review board's approval was obtained before the enrollment of patients. A convenience sample was obtained from admissions to the medical/surgical Critical Care Units of a 300-bed Midwestern not-for-profit hospital. Patients were excluded from the study if they did not understand English, had a history of psychiatric disorder, were unable to see pictures, were unable to hear instructions, or had a Richmond Agitation-Sedation Scale of less than -3 or greater than +4. Participants were enrolled during a 3-week period. Additional information to describe the actual sample included age, gender, medical or surgical diagnosis (no specific diagnosis), length of time in critical care, and whether the patient is receiving benzodiazepine or opioid medications. No identifiable data was collected. Patients were assessed for delirium using the CAM-ICU. All assessments will be performed by the study nurse. Each patient was assessed 3 times a day: between 8 AM and 10 AM, between 12 PM and 2 PM, and between 8 PM and 10 PM. These times were selected because they correlate with the routine assessment times of the unit. The hours between 10 PM and 8 AM were excluded to allow the patient to sleep. Sleep deprivation is identified as a risk factor for delirium, so it was decided to allow the patient to sleep. Delirium was recorded as present or delirium absent using the CAM-ICU criteria.
Results:
During the 3-week study period, 15 patients were enrolled in the study. The mean age was 64.2 years, range 18 to 84 years. Most participants were male (60%). The mean length of stay at the time of assessment was 4.06 days (range 1-14 days). No differences were noted between patients that developed delirium, and use of benzodiazepines or opioids, mechanical ventilation, had a medical or surgical diagnosis. Delirium scores were not different by time of assessment. The percentage of patients screening positive did not significantly differ for the 3 assessment times: 8 AM to 10 AM (87%), 2 PM to 4 PM (73%), and 8 PM to 10 PM (63%). Of the 15 participants, 3 patients (20%) had a change in the results of the delirium assessment during the day. All 3 patients went from screening positive for delirium to negative. The negative result continued with subsequent screenings. Age was not a factor in whether the assessment changed or not. The ages of the patients that had a change in assessment results were 78, 53, and 18 years old.
Conclusions:
According to the results of this study, there does not appear to be a time of day when delirium is more prevalent. The intensity of delirium may fluctuate during the day, but the assessment results do not fluctuate. Although this study does not suggest when the best time to assess for delirium, it would be beneficial to assess at least once a shift. Each critical care nurse should be able to assess for delirium using the CAM-ICU. By assessing for delirium each shift, the nurse can identify delirium as it develops and initiate treatment earlier than if the assessment was performed once a day.
Implications for Practice:
Delirium assessment can be performed any time during the day without affecting the results. However, if assessments are performed several times a day, the onset of delirium can be identified and treatment initiated.