Role of dexmedetomidine in the treatment of delirium in critically ill patients: a systematic review and meta-analysis

Pharmacologic Management of End-of-Life Delirium: Translating Evidence into Practice

End-of-life delirium affects a vast majority of patients before death. It is highly distressing and often associated with restlessness or agitation. Unlike delirium in other settings, it is considered irreversible, and non-pharmacologic measures may be less feasible. The objective of this review is to provide an in-depth discussion of the clinical trials on delirium in the palliative care setting, with a particular focus on studies investigating pharmacologic interventions for end-of-life delirium. To date, only six randomized trials have examined pharmacologic options in palliative care populations, and only two have focused on end-of-life delirium. These studies suggest that neuroleptics and benzodiazepines may be beneficial for the control of the terminal restlessness or agitation associated with end-of-life delirium. However, existing studies have significant methodologic limitations. Further studies are needed to confirm these findings and examine novel therapeutic options to manage this distressing syndrome.

Dexmedetomidine versus haloperidol for sedation of non-intubated patients with hyperactive delirium during the night in a high dependency unit: study protocol for an open-label, parallel-group, randomized controlled trial (DEX-HD trial)

BACKGROUND

Delirium is common in critically ill patients. Haloperidol has long been used for the treatment of delirium. Dexmedetomidine has recently been used to treat delirium among intubated critically ill patients. However, the efficacy of dexmedetomidine for delirium in non-intubated critically ill patients remains unknown. We hypothesize that dexmedetomidine is superior to haloperidol for sedation of patients with hyperactive delirium, and would reduce the prevalence of delirium among non-intubated patients after administration. We will conduct a randomized controlled trial to compare dexmedetomidine and haloperidol for the treatment of nocturnal hyperactive delirium in non-intubated patients in high dependency units (HDUs).

METHODS

This is an open-label, parallel-group, randomized controlled trial to compare the efficacy and safety of dexmedetomidine and haloperidol for nocturnal hyperactive delirium in non-intubated patients at two HDUs of a tertiary hospital. We will recruit consecutive non-intubated patients who are admitted to the HDU from the emergency room, and allocate them in a 1:1 ratio to the dexmedetomidine or haloperidol group in advance. The allocated investigational drug will be administered only when participants develop hyperactive delirium (Richmond Agitation-Sedation Scale [RASS] score ≥1 and a positive score on the Confusion Assessment Method for the ICU between 19:00 and 6:00 the next day) during the night at an HDU. Dexmedetomidine is administered continuously, while haloperidol is administered intermittently. The primary outcome is the proportion of participants who achieve the targeted sedation level (RASS score of between -3 and 0) 2h after the administration of the investigational drug. Secondary outcomes include the sedation level and prevalence of delirium on the day following the administration of the investigational drugs, and safety. We plan to enroll 100 participants who develop nocturnal hyperactive delirium and receive one of the two investigational drugs.

DISCUSSION

This is the first randomized controlled trial to compare the efficacy and safety of dexmedetomidine and haloperidol for sedation of non-intubated critically ill patients with hyperactive delirium in HDUs. The results of this study may confirm whether dexmedetomidine could be another option to sedate patients with hyperactive delirium.

TRIAL REGISTRATION

Japan Registry of Clinical Trials, jRCT1051220015, registered on 21 April 2022.

Perioperative neurocognitive disorders: A narrative review focusing on diagnosis, prevention, and treatment

Perioperative neurocognitive disorders (NCDs) refer to neurocognitive abnormalities detected during the perioperative periods, including preexisting cognitive impairment, preoperative delirium, delirium occurring up to 7 days after surgery, delayed neurocognitive recovery, and postoperative NCD. The Diagnostic and Statistical Manual of Mental Disorders‐5th edition (DSM‐5) is the golden standard for diagnosing perioperative NCDs. Given the impracticality of using the DSM‐5 by non‐psychiatric practitioners, many diagnostic tools have been developed and validated for different clinical scenarios. The etiology of perioperative NCDs is multifactorial and includes predisposing and precipitating factors. Identifying these risk factors is conducive to preoperative risk stratification and perioperative risk reduction. Prevention for perioperative NCDs should include avoiding possible contributors and implementing nonpharmacologic and pharmacological interventions. The former generally includes avoiding benzodiazepines, anticholinergics, prolonged liquid fasting, deep anesthesia, cerebral oxygen desaturation, and intraoperative hypothermia. Nonpharmacologic measures include preoperative cognitive prehabilitation, comprehensive geriatric assessment, implementing fast‐track surgery, combined use of regional block, and sleep promotion. Pharmacological measures including dexmedetomidine, nonsteroidal anti‐inflammatory drugs, and acetaminophen are found to have beneficial effects. Nonpharmacological treatments are the first‐line measures for established perioperative NCDs. Pharmacological treatments are still limited to severely agitated or distressed patients.

Feasibility of low-dose dexmedetomidine for prevention of postoperative delirium after intracranial operations: a pilot randomized controlled trial

Background

Clinical trials have shown that dexmedetomidine might decrease the occurrence of postoperative delirium after major surgery, but neurosurgical patients were excluded from these studies. We aimed to determine the feasibility of conducting a full-scale randomized controlled trial of the effect of prophylactic low-dose dexmedetomidine on postoperative delirium in patients after elective intracranial operation for brain tumors.

Methods

In this single-center, parallel-arm pilot randomized controlled trial, adult patients who underwent an elective intracranial operation for brain tumors were recruited. Dexmedetomidine (0.1 μg/kg/hour) or placebo was continuously infused from intensive care unit (ICU) admission on the day of surgery until 08:00 AM on postoperative day one. Adverse events during the study-drug administration were recorded. The primary feasibility endpoint was the occurrence of study-drug interruption. Delirium was assessed twice daily with the Confusion Assessment Method for the ICU during the first five postoperative days. The assessable rate of delirium evaluation was documented.

Results

Sixty participants were randomly assigned to receive either dexmedetomidine (n = 30) or placebo (n = 30). The study-drug was stopped in two patients (6.7%) in the placebo group due to desaturation after new-onset unconsciousness and an unplanned reoperation for hematoma evacuation and in one patient (3.3%) in the dexmedetomidine group due to unplanned discharge from the ICU. The absolute difference (95% confidence interval) of study-drug interruption between the two groups was 3.3% (− 18.6 to 12.0%), with a noninferiority P value of 0.009. During the study-drug infusion, no bradycardia occurred, and hypotension occurred in one patient (3.3%) in the dexmedetomidine group. Dexmedetomidine tended to decrease the incidence of tachycardia (10.0% vs. 23.3%) and hypertension (3.3% vs. 23.3%). Respiratory depression, desaturation, and unconsciousness occurred in the same patient with study-drug interruption in the placebo group (3.3%). Delirium was evaluated 600 times, of which 590 (98.3%) attempts were assessable except in one patient in the placebo group who remained in a coma after an unplanned reoperation.

Conclusions

The low rate of study-drug interruption and high assessable rate of delirium evaluation supported a fully powered trial to determine the effectiveness of low-dose dexmedetomidine on postoperative delirium in patients after intracranial operation for brain tumors.

Trial registration

The trial was registered at ClinicalTrials.gov (NCT04494828) on 31/07/2020.

Older trauma patients are at high risk of delirium, especially those with underlying dementia or baseline frailty

BACKGROUND

Given the increasing numbers of older patients presenting with trauma, and the potential influence of delirium on outcomes, we sought to investigate the proportion of such patients who were diagnosed with delirium during their stay-and patient factors associated therewith-and the potential associations between delirium and hospital length of stay (LOS). We hypothesized that delirium would be common, associated with certain patient characteristics, and associated with long hospital LOS (highest quartile).

METHODS

We conducted a retrospective observational cohort study of all trauma patients aged ≥65 years presenting in September to October 2019, interrogating medical records and the institutional trauma database. The primary outcome measure was occurrence of delirium.

RESULTS

Among 99 eligible patients, delirium was common, documented in 23% (23 of 99). On multivariable analysis, adjusting for age, frailty and history of dementia, frailty (OR 4.09, 95% CI 1.08 to 15.53, p=0.04) and dementia (OR 5.23, 95% CI 1.38 to 19.90, p=0.02) were independently associated with likelihood of delirium. Standardized assessment tools were underused, with only 34% (34 of 99) screened within 4 hours of arrival. On univariate logistic regression analysis, having an episode of delirium was associated with long LOS (highest quartile), OR of 5.29 (95% CI 1.92 to 14.56, p<0.001). In the final multivariable model, adjusting for any (non-delirium) in-hospital complication, delirium was independently associated with long LOS (≥16 days; OR 4.81, p=0.005).

DISCUSSION

In this study, delirium was common. History of dementia and baseline frailty were associated with increased risk. Delirium was independently associated with long LOS. However, many patients did not undergo standardized screening at admission. Early identification and targeted management of older patients at risk of delirium may reduce incidence and improve care of this vulnerable cohort. These data are hypothesis generating, but support the need for initiatives which improve delirium care, acknowledging the complex interplay between frailty and other geriatric syndromes in the older trauma patients.

LEVEL OF EVIDENCE

III.