Monitoring delirium in the intensive care unit: Diagnostic accuracy of the CAM-ICU tool when performed by certified nursing assistants - A prospective multicenter study

Background: Monitoring delirium in critically ill patients is recognized as a major challenge. Although involving certified nursing assistants could be a valuable help in this field, such strategy has never been formally investigated.

Objectives: Following theoretical training, we conducted a prospective multicenter study assessing the diagnostic accuracy of a CAM-ICU delirium screening strategy performed by CNAs in clinical settings, compared to parallel blinded evaluations conducted by nurses and physicians.

Methods: From October 2020 to June 2022, adult intensive care patients admitted in three French University teaching hospitals with Richmond Agitation Sedation Scale ≥-2 were independently assessed for delirium by the three members of the care team (clinical nursing assistant, nurse and physician) using CAM-ICU in a random order. Physician's assessment served as the reference standard for comparisons.

Results: We analyzed results from 268 triplets of CAM-ICU assessments performed sequentially on 203 patients. Prevalence of delirium was 22%. Compared to physician's assessments, clinical nursing assistants demonstrated a sensitivity (Se) of 88% CI95% [80-96] and a specificity (Sp) of 95% [92-98] in detecting delirium. There was no significant difference in the performance of clinical nursing assistants and nurses (Se = 90 % [82-97] p = 0.77, Sp = 98 % [95-100] p = 0.19). We observed high agreement between results obtained by physicians and clinical nursing assistants (ĸ = 0.82) and clinical nursing assistants performance remained consistent in the subgroups at higher risk of delirium.

Conclusion: Evaluation of the CAM-ICU by clinical nursing assistants is feasible and should be seen as an opportunity to increase routine monitoring of delirium in intensive care patients.

Implication for clinical practice: Delirium is a severe and underestimated complication of intensive care unit stay. This study results demonstrate the great performance of trained clinical nursing assistants in detecting delirium using the CAM-ICU. Further research is needed to define the most effective role for clinical nursing assistants in the routine management of delirium in intensive care patients.