Delirium during Weaning from Mechanical Ventilation

Abstract

Background. We compare the incidence of delirium before and after extubation and identify the risk factors and possible predictors for the occurrence of delirium in this group of patients. Methods. Patients weaned from mechanical ventilation (MV) and extubated were included. The assessment of delirium was conducted using the confusion assessment method for the ICU and completed twice per day until discharge from the intensive care unit. Results. Sixty-four patients were included in the study, 53.1% of whom presented with delirium. The risk factors of delirium were age (P = 0.01), SOFA score (P = 0.03), APACHE score (P = 0.01), and a neurological cause of admission (P = 0.01). The majority of the patients began with delirium before or on the day of extubation. Hypoactive delirium was the most common form. Conclusion. Acute (traumatic or medical) neurological injuries were important risk factors in the development of delirium. During the weaning process, delirium developed predominantly before or on the same day of extubation and was generally hypoactive (more difficult to detect). Therefore, while planning early prevention strategies, attention must be focused on neurological patients who are receiving MV and possibly even on patients who are still under sedation.

Figure 1

Eligible patients included and excluded from the study. MV: mechanical ventilation; GCS: Glasgow Coma Scale.

Figure 2

(a) Incidence of new-diagnosed delirium according to extubation day (D 0); (b) cumulative delirium incidence.

Figure 3

Worst agitation-drowsiness (RASS) values during CAM-ICU assessment (n = 64). Richmond Agitation Sedation Scale (RASS) value ≤1 indicates deepest drowsiness, while value ≥1 indicates psychomotor agitation. CAM-ICU: confusion assessment method for the ICU.

Figure 4

Multivariable analysis of delirium predictors. (a) Values of canonical root by linear combination of age, SOFA score, and APACHE II score according to the level obtained by each patient and categorised in accordance with the occurrence or absence of delirium. (b) Mean values ±95% confidence interval for the canonical root of each speciality category. SOFA: sequential organ failure assessment; APACHE II: acute physiology and chronic health evaluation.