Early Sedation Intensity and Psychological Outcomes in Critically Ill Adults

Long-term psychological impairment is a major concern for intensive care unit (ICU) survivors. Early deep sedation during mechanical ventilation has been associated with poor short-term outcomes and mortality after ICU discharge; however, its relationship with psychological outcomes remains unclear.

To investigate sedation intensity during the first 24 h of mechanical ventilation and its association with psychological impairment 3 months after ICU discharge.

This retrospective ancillary analysis of a single-centre cohort study was conducted in two general ICUs at a university hospital in Japan. Eligible patients stayed in the ICU for more than 48 h and received mechanical ventilation for more than 8 h. Sedation intensity was quantified using the Sedation Index (SI) and Agitation Index (AI) derived from Richmond Agitation-Sedation Scale scores during the first 24 h. Psychological impairment 3 months post-ICU discharge was assessed based on symptoms of post-traumatic stress, anxiety and depression. Associations were examined using hierarchical logistic regression.

Among 130 participants, the median age was 64 years, and the median ventilation duration was 14 h. The median SI was 3.0; 47% had SI > 3, and 8.5% had AI > 0. Sedation intensity showed no significant association with psychological impairment (SI: adjusted odds ratio [OR] 0.87, 90% confidence interval [CI] 0.57-1.33, p = 0.59; AI: adjusted OR 0.21, 90% CI 0.01-3.08, p = 0.34). However, any agitation during the ICU stay was associated with psychological outcomes (adjusted OR 2.61, 90% CI 1.16-5.88, p = 0.05).

This study did not identify a statistically significant association between early sedation intensity and psychological impairment 3 months after ICU discharge.

Critical care nurses should carefully titrate sedation from the initiation of mechanical ventilation to avoid unnecessary deep sedation, considering sedation intensity over time, while actively assessing agitation and its underlying causes.