Deep sedation linked to subsequent delusional memories in acute COVID-19 survivors

The authors wrote, "the study contributes to a better understanding of the potential adverse effects of deep sedation in survivors of COVID-19, indicating an independent, significant association with the incidence of delusional recalls." 

Critical care survivors sustain several sequelae following admission to intensive care medicine, and the COVID-19 (Coronavirus Disease 2019) pandemic has added further challenges. ICM memories play a significant role, and delusional memories are associated with poor outcomes post-discharge, including a delayed return to work and sleep problems. Deep sedation has been linked with a higher risk of perceiving delusional memories, bringing a move toward lighter sedation. However, reports on post-ICM memories in COVID-19 are limited, and the influence of deep sedation has not been defined completely.

Against the above background, A. Braga and colleagues from Portugal aimed to evaluate ICM-memory recall in COVID-19 survivors and their relation with deep sedation.

The study evaluated adult COVID-19 ICM survivors admitted to a Portuguese University Hospital between 2020 and 2021 1 to 2 months post-discharge using the "ICU Memory Tool" to assess emotional, real, and delusional memories.

The authors reported the following findings:

• The study included 132 patients (67% male; median age = 62 years, Simplified Acute Physiology Score [SAPS]-II = 35, Acute Physiology and Chronic Health Evaluation [APACHE]-II = 15, ICM stay = nine days).
• Approximately 42% received deep sedation (median duration = 19 days).
• Most participants reported real (87%) and emotional (77%) recalls, with lesser delusional memories (36.4%).
• Deeply sedated patients reported significantly fewer real memories (78.6% vs 93.4%) and increased delusional memories (60.7% vs 18.4%), with no difference in emotional memories (75% vs 80.4%).
• In multivariate analysis, deep sedation had a significant, independent association with delusional memories, increasing their likelihood by approximately 6 (OR = 6.274) without influencing real or emotional memories.

The study describes the deep sedation effects on subsequent delusional memories and adds to the increasing evidence that lighter sedation strategies should be employed whenever possible.

"Although further studies are needed to support these findings, they suggest that strategies to minimize sedation should be favoured, aiming to improve long-term recovery," the researchers concluded.

Reference:

Braga A, Martins S, Ferreira AR, et al. Influence of Deep Sedation in Intensive Care Medicine Memories of Critical COVID-19 Survivors. Journal of Intensive Care Medicine. 2023;0(0). doi:10.1177/08850666231156782