Ketamine infusion as effective as Benzodiazepine infusion for arresting delirium in ICU patients; Study

A recent study conducted at a large quaternary academic center examined the effectiveness of sedative-dose ketamine versus benzodiazepines in critically ill patients. The findings of this study were published in the Journal of Intensive Care Medicine

This single-center, retrospective cohort study included adult patients who were admitted to the intensive care unit (ICU) between May 5, 2018 and December 1, 2021. The patients were eligible if they were administered continuous infusions of either sedative-dose ketamine or benzodiazepines (specifically lorazepam or midazolam) for at least 24 hours and required mechanical ventilation for a minimum of 48 hours.

A total of 165 patients were included in the study. Of these, 64 patients received ketamine, while 101 patients were treated with benzodiazepines (35 with lorazepam and 78 with midazolam). The study majorly measured the median number of delirium or coma-free days within the first 28 days of hospitalization.

The median (IQR) delirium or coma-free days were 1.2 (0.0, 3.7) for the ketamine group and 1.8 (0.7, 4.6) for the benzodiazepine group, with a p-value of 0.13 which indicated no statistically significant difference. However, several other notable differences were;

• The patients in the ketamine group spent a significantly lower proportion of time with Richmond Agitation-Sedation Scale (RASS) scores between -3 to +4 that indicated varying levels of agitation and sedation.
  
• The ketamine group required significantly higher doses and longer durations of supplemental sedatives like propofol and fentanyl infusions when compared to the benzodiazepine group.
• The patients who received ketamine had a significantly longer ICU stay than the patients treated with benzodiazepines.

The study found that the use of sedative-dose ketamine did not result in a significant difference in the number of delirium or coma-free days when compared to benzodiazepines. Despite this, the ketamine group underwent more time under heavy sedation, increased use of additional sedatives and extended ICU stays.

These findings are crucial for clinicians who consider sedative options for critically ill patients. The increased need for additional sedatives and prolonged ICU stays with ketamine use may influence decisions toward opting for benzodiazepines in similar clinical scenarios. Further research may be imperative to explore the underlying reasons for these differences and to determine the best sedation practices for improving patient outcomes in the ICU.

Source:

Vollmer, N. J., Wieruszewski, E. D., Nei, A. M., Mara, K. C., Rabinstein, A. A., & Brown, C. S. (2024). Impact of Continuous Infusion Ketamine Compared to Continuous Infusion Benzodiazepines on Delirium in the Intensive Care Unit. In Journal of Intensive Care Medicine. SAGE Publications. https://doi.org/10.1177/08850666241253541