A comparison of the confusion assessment method for the intensive care unit and the NEECHAM confusion scale in intensive care delirium assessment
KeywordsGlasgow Coma Scale Noncardiac Surgery Confusion Assessment Method Delirious Patient Delirium Assessment
Reports indicate an incidence of intensive care delirium of 11–87%. The confusion assessment method for the intensive care unit (CAM-ICU) is widely used in delirium assessment in ICUs. However, its binomial results constrain the evaluation of severity. The NEECHAM confusion scale has recently been validated for use in the ICU and uses a numeric assessment. This scale allows the patients to be classified in four categories of delirium severity (normal, at-risk, mild to early, moderate to severe). In this study we investigated the diagnostic value of the NEECHAM referring to the CAM-ICU.
A consecutive sample of 106 patients in a mixed ICU (cardiac surgery (CS) 35%, noncardiac surgery (NCS) 26%, internal medicine (IM) 39%, age 62 ± 14 years, male 63%) was assessed after a stay in the ICU ≥24 hours. All patients with a Glasgow Coma Scale ≥10 and age ≥18 years were included. A nurse researcher simultaneously assessed both scales once daily in the morning. A total of 272 paired observations were made. Data were analyzed using the NEECHAM cut-off values of ≤26 (at-risk), ≤24 (mild delirium), and ≤19 (severe delirium).
Using the CAM-ICU the overall prevalence was 15%. Prevalences in CS, NCS and IM were 9%, 14% and 21%, respectively. Using the NEECHAM scale, the overall prevalence was 33% (16.5% mild, 16.5% severe) and 36%, 21% and 38% for the three patient categories, respectively. Sensitivity was 100%, specificity was 79%, positive predictive value was 46% and negative predictive value was 100%. Using the cut-off value ≤19, sensitivity was 83% and specificity was 96%. All positive CAM-ICU patients were detected by the NEECHAM (85% severe, 15% mild). However, 21% of the CAM-ICU negative patients had a NEECHAM value that diagnoses delirium (4% severe, 17% mild). Consequently, 27% of the CS group (19% severe, 8% mild), 7% of the NCS group (7% mild) and 17% of the IM group (2% severe, 15% mild) were diagnosed to be delirious using the NEECHAM and not delirious using the CAM-ICU.
The NEECHAM delirium scale identified all cases of delirium that were detected by the CAM-ICU. Moreover, additional delirious patients were identified, especially in the CS group. In this pilot experience, the NEECHAM scale was a valuable screening tool for intensive care.