Journal Article Annotations
2020, 3rd Quarter
Annotations by Maalobeeka Gangopadhyay, MD
PUBLICATION #1 — Delirium
Dexmedetomidine infusion did not prevent atrial fibrillation compared to placebo in the setting of cardiac surgery. Dexemedetomidine use at anesthetic induction and for 24 hours non-significantly led to increased rates of delirium compared to placebo. In addition, there was not a significant difference in kidney function or experience of post-incisional pain between the two groups. Length of stay in the ICU was also longer in those given dexmedetomidine.
Strengths and weaknesses:
Strengths of the study include that its design was blinded, placebo-controlled, and randomized and included multiple centers. In addition, it standardized delirium determination across sites with the RASS and CAM-ICU as well as twice a day evaluation by the research team and review of nursing notes. Weaknesses of the study included the confounding use of benzodiazepines and opioids and not examining if this contributed to the hypotension that developed or changed use of dexmedetomidine. Also the age range enrolled in the study was quite broad 18 to 85 years old and it demonstrates that delirium risk was greater in the >64yo group so this may have contributed to the lack of benefit seen with dexmedetomidine as well.
While there are many proposed benefits to using dexmedetomidine to mitigate delirium development, this is a large study in a cardiac surgery population where delirium incidence was not improved with dexemedetomidine exposure. The study does reveal that hypotension and age are predictors of delirium development so the use, timing, and dosage of dexmedetomidine should be considered more carefully.
Type of study(EBM guide):
Randomized controlled trial
Preoperative use of angiotensin-converting enzyme (ACE) inhibitors and angiotensin receptor blockers (ARB) in a non-cardiac postoperative critical care population did not reduce postoperative delirium; however postoperative use of ACE inhibitors and ARBs was associated with ~50% less likelihood of delirium and delayed median onset of delirium 64 hours versus 19 hours in those not on ARBs or ACE inhibitors.
Strength and weaknesses:
Strengths of this study included controlling for benzodiazepine use leading to delirium in the sensitivity analysis and the use of the CAM-ICU to detect delirium. A weakness of the study was that there was no analysis of the contribution of opioids or other medications in the postoperative period for delirium.
Use of ACE inhibitors and ARBs after surgery at therapeutic doses leads to reduction of delirium and delayed onset of delirium.
Type of study(EBM guide):
The authors of this literature review examined publications in the past 20 years regarding benzodiazepine use and its association with delirium. In addition to reviewing the studies that demonstrate benzodiazepine use increases delirium, it points out studies in the palliative care population and a meta-analysis, where benzodiazepine use with haloperidol was superior to placebo in addressing delirium.
Type of study (EBM guide):
This article describes the design and implementation of a randomized cluster crossover trial that will look at benzodiazepine use in cardiac surgery and the impact on postoperative delirium. The results of this study will contribute knowledge to the ongoing controversy about benzodiazepine use in delirium.
Type of study (Randomized cluster crossover pilot study