Update on Pharmacotherapy for Prevention and Treatment of Post-operative Delirium: A Systematic Evidence Review

Association between intraoperative ketamine and the incidence of emergence delirium in laparoscopic surgeries: an observational study

BACKGROUND

Emergence Delirium (ED) is an essential condition in the immediate postoperative period. Systematic review and meta-analysis of randomized controlled trials have concluded that the effect of ketamine on postoperative delirium remains unclear. The present study sought to evaluate if the intraoperative use of ketamine for postoperative analgesia is associated with postoperative ED in laparoscopic surgeries.

METHODS

A prospective observational study was performed in the PostAnesthetic Care Unit (PACU) to evaluate patients who had undergone laparoscopic surgery under a rigid intraoperative anesthesia protocol from July 2018 to January 2019. Patients submitted to laparoscopic surgery for cholecystectomy, oophorectomy, or salpingectomy with a score ≥1 on the Richmond Assessment Sedation Scale (RASS) or ≥2 on the Nursing Delirium Screening Scale (Nu-DESC) were considered to have ED. t-test, Chi-Square test or Fisher's exact tests were used for comparison.

RESULTS

One hundred and fifteen patients were studied after laparoscopic surgery. Seventeen patients (14.8%) developed ED, and the incidence of ED in patients who received ketamine was not different from that of other patients (18.3% vs. 10.6%, p = 0.262). Patients with ED had more postoperative pain and morphine requirement at the PACU (p = 0.005 and p = 0.025, respectively). Type of surgery (general surgery, OR = 6.4, 95% CI 1.2‒35.2) and postoperative pain (OR = 3.7, 95% CI 1.2‒11.4) were risk factors for ED.

CONCLUSION

In this study, no association was found between ED and intraoperative administration of ketamine in laparoscopic surgeries. Type of surgery and postoperative pain were risk factors for ED.

The pharmacotherapeutic management of postoperative delirium: an expert update

INTRODUCTION

Postoperative delirium is a common sequela in older adults in the peri-operative period leading to poor outcomes with a complex pathophysiology which has led to a variety of different pharmacologic agents employed in attempts to prevent and treat this syndrome. No pharmacologic agent has been approved to treat this disorder, but this review discusses the pharmacologic strategies which have been tried based on the hypotheses of the causation of the syndrome including neurotransmitter imbalance, inflammation, and oxidative stress.

AREAS COVERED

Systematic reviews and meta-analyses of randomized clinical trials (RCTs) were included via search of electronic databases specifically for the terms postoperative delirium and pharmacologic treatments. With this approach, the recurrent topics of analgesia and sedation, antipsychotics, acetylcholinesterase inhibitors (AchE-Is), inflammation, and melatonin were emphasized and provided the outline for this review.

EXPERT OPINION

Research evidence does not support any particular agent in any of the pharmacologic classes reviewed. However, there is some potential benefit with dexmedetomidine, melatonin, and the monitoring of anesthetic agents all of which need further clinical trials to validate these conclusions. Exploration of ways to improve studies and the application of novel pharmacologic agents may offer future benefit.

Deprescribing in the Pharmacologic Management of Delirium: A Randomized Trial in the Intensive Care Unit

OBJECTIVE

Benzodiazepines and anticholinergics are risk factors for delirium in the intensive care unit (ICU). We tested the impact of a deprescribing intervention on short-term delirium outcomes.

DESIGN

Multisite randomized clinical trial.

SETTING

ICUs of three large hospitals.

PARTICIPANTS

Two hundred adults aged 18 years or older and admitted to an ICU with delirium, according to the Richmond Agitation-Sedation Scale and the Confusion Assessment Method for the ICU (CAM-ICU). Participants had a contraindication to haloperidol (seizure disorder or prolonged QT interval) or preference against haloperidol as a treatment for delirium, and were excluded for serious mental illness, stroke, pregnancy, or alcohol withdrawal. Participants were randomized to a deprescribing intervention or usual care. The intervention included electronic alerts combined with pharmacist support to deprescribe anticholinergics and benzodiazepines.

MEASUREMENTS

Primary outcomes were delirium duration measured by the CAM-ICU and severity measured by the Delirium Rating Scale Revised-98 (DRS-R-98) and the CAM-ICU-7; secondary outcomes included adverse events and mortality.

RESULTS

Participants had a mean age of 61.8 (SD = 14.3) years, 59% were female, and 52% were African American, with no significant differences in baseline characteristics between groups. No differences between groups were identified in the number exposed to anticholinergics (P = .219) or benzodiazepines (P = .566), the median total anticholinergic score (P = .282), or the median total benzodiazepine dose in lorazepam equivalents (P = .501). Neither median delirium/coma-free days (P = .361) nor median change in delirium severity scores (P = .582 for DRS-R-98; P = .333 for CAM-ICU-7) were different between groups. No differences in adverse events or mortality were identified.

CONCLUSIONS

When added to state-of-the-art clinical services, this deprescribing intervention had no impact on medication use in ICU participants. Given the age of the population, results of clinical outcomes may not be easily extrapolated to older adults. Nonetheless, improved approaches for deprescribing or preventing anticholinergics and benzodiazepines should be developed to determine the impact on delirium outcomes. J Am Geriatr Soc 67:695-702, 2019.

Pharmacologic prevention of postoperative delirium after on-pump cardiac surgery: A meta-analysis of randomized trials

BACKGROUND

Postoperative delirium is a prevalent and disabling mental disorder in patients undergoing on-pump cardiac surgery. There is some evidence that the use of pharmacological interventions may reduce the risk of developing of postoperative delirium. Therefore, the aim of this meta-analysis was to determine the effect of pharmacologic agents for the prevention postoperative delirium after cardiac surgery.

METHODS

Randomized controlled trials (RCTs) were identified through a systematic literature search of electronic databases and article references up to October 2016. End points included incidence of postoperative delirium, severity of postoperative delirium, cognitive disturbances of postoperative delirium, duration of postoperative delirium, length of stay in intensive care unit (ICU) and hospital, and short-term mortality.

RESULTS

A total of 14 RCTs with an aggregate of 14,139 patients were included. The results of the present meta-analysis show that pharmacologic agents significantly decrease postoperative delirium [relative risk (RR), 0.83; 95% confidence interval (95% CI), 0.75-0.91, P < .00001] and duration of postoperative delirium (RR = -0.37, 95% CI = -0.47 to -0.27, P < .00001) after on-pump cardiac surgery. In addition, subgroup analysis shows that dexamethasone and dexamethasone were associated with a trend toward a reduction in postoperative delirium (RR, 0.45; 95% CI, 0.30-0.66, P < .0001; RR, 0.80; 95% CI, 0.68-0.93, P = .003, respectively). However, our results fail to support the assumption that pharmacologic prophylaxis is associated with a positively reduction in short-term mortality, length of ICU, or hospital stay.

CONCLUSION

This meta-analysis suggests that the perioperative use of pharmacologic agents can prevent postoperative delirium development in patients undergoing cardiac surgery. However, there remain important gaps in the evidence base on a few small studies with multiple limitations. Further large-scale, high-quality RCTs are needed in this area.

Use of Orally Disintegrating Olanzapine During Electroconvulsive Therapy for Prevention of Postictal Agitation

A major medical problem for patients undergoing electroconvulsive therapy (ECT) is the occurrence of postictal agitation (PIA). This phenomenon is associated with confusion and disorientation that can have severe clinical implications for the safety of the patient and health care professionals. Many different pharmacological strategies have been used to prevent PIA. We present data on 40 patients who suffered from PIA after a course of ECT and evaluate the prophylactic use of orally disintegrating olanzapine in the prevention of PIA in subsequent ECT treatments.