A systematic review of interventions to facilitate extubation in patients difficult-to-wean due to delirium, agitation, or anxiety and a meta-analysis of the effect of dexmedetomidine

Prolonged Mechanical Ventilation, Weaning, and the Role of Tracheostomy

Depending on the definitional criteria used, approximately 5% to 10% of critical adults will require prolonged mechanical ventilation with longer-term outcomes that are worse than those ventilated for a shorter duration. Outcomes are affected by patient characteristics before critical illness and its severity but also by organizational characteristics and care models. Definitive trials of interventions to inform care activities, such as ventilator weaning, upper airway management, rehabilitation, and nutrition specific to the prolonged mechanical ventilation patient population, are lacking. A structured and individualized approach developed by the multiprofessional team in discussion with the patient and their family is warranted.

Mechanical Ventilation in Patients with Traumatic Brain Injury: Is it so Different?

Patients with traumatic brain injury (TBI) frequently require invasive mechanical ventilation and admission to an intensive care unit. Ventilation of patients with TBI poses unique clinical challenges, and careful attention is required to ensure that the ventilatory strategy (including selection of appropriate tidal volume, plateau pressure, and positive end-expiratory pressure) does not cause significant additional injury to the brain and lungs. Selection of ventilatory targets may be guided by principles of lung protection but with careful attention to relevant intracranial effects. In patients with TBI and concomitant acute respiratory distress syndrome (ARDS), adjunctive strategies include sedation optimization, neuromuscular blockade, recruitment maneuvers, prone positioning, and extracorporeal life support. However, these approaches have been largely extrapolated from studies in patients with ARDS and without brain injury, with limited data in patients with TBI. This narrative review will summarize the existing evidence for mechanical ventilation in patients with TBI. Relevant literature in patients with ARDS will be summarized, and where available, direct data in the TBI population will be reviewed. Next, practical strategies to optimize the delivery of mechanical ventilation and determine readiness for extubation will be reviewed. Finally, future directions for research in this evolving clinical domain will be presented, with considerations for the design of studies to address relevant knowledge gaps.

Preoperative anxiety as an independent predictor of postoperative delirium in older patients undergoing elective surgery for lumbar disc herniation

BACKGROUND

Anxiety is common in older patients suffering from lumbar disc herniation. Postoperative delirium is related to poor prognosis. But the relationship between preoperative anxiety and postoperative delirium among older patients undergoing elective surgery for lumbar disc herniation is not clear.

AIMS

The study aimed to investigate if preoperative anxiety is an independent risk factor of postoperative delirium among older patients undergoing elective surgery for lumbar disc herniation.

METHODS

The medical records of 1290 patients undergoing elective surgery for lumbar disc herniation at a single institution from 2016 through 2021 were reviewed. Of 863 eligible patients, 225 (26.1%) patients had been diagnosed with anxiety by a board-certified psychiatrist and constituted the Anxiety group; the remaining 638 patients constituted the no-anxiety group. The demographics, baseline, operative variable and postoperative complications were collected and compared between the two groups. The primary outcome of this study was the incidence of delirium, according to the Diagnostic and Statistical Manual of Mental Disorders-Fifth Edition, during a hospital stay after surgery for lumbar disc herniation. The relationship between anxiety and postoperative delirium was determined through multivariate logistic regression analysis.

RESULTS

The demographics and comorbidity were similar between the two groups, except for age, sex, alcohol use and cerebrovascular disease. The operative variables were different between the two groups. The incidence of postoperative complications other than postoperative delirium was also similar between the two groups. In total, 86 patients (9.97%) had an episode of postoperative delirium, with anxiety group patients experiencing approximately a twofold higher rate (15.6% vs 7.99%). In a multivariate logistic regression analysis, anxiety was an independent predictor of postoperative delirium in older patients undergoing elective surgery for lumbar disc herniation (OR 2.228, 95% CI 1.494-3.416, p = 0.009).

CONCLUSION

This study suggests that anxiety is an independent risk factor of postoperative delirium among older patients undergoing elective surgery for lumbar disc herniation. Preoperative anxiety assessment can help to identify older patients at high risk of postoperative delirium and facilitate perioperative management of older patients undergoing elective surgery for lumbar disc herniation.

Dexmedetomidine vs other sedatives in critically ill mechanically ventilated adults: a systematic review and meta-analysis of randomized trials

Conventional gabaminergic sedatives such as benzodiazepines and propofol are commonly used in mechanically ventilated patients in the intensive care unit (ICU). Dexmedetomidine is an alternative sedative that may achieve lighter sedation, reduce delirium, and provide analgesia. Our objective was to perform a comprehensive systematic review summarizing the large body of evidence, determining if dexmedetomidine reduces delirium compared to conventional sedatives. We searched MEDLINE, EMBASE, CENTRAL, ClinicalTrials.gov and the WHO ICTRP from inception to October 2021. Independent pairs of reviewers identified randomized clinical trials comparing dexmedetomidine to other sedatives for mechanically ventilated adults in the ICU. We conducted meta-analyses using random-effects models. The results were reported as relative risks (RRs) for binary outcomes and mean differences (MDs) for continuous outcomes, with corresponding 95% confidence intervals (CIs). In total, 77 randomized trials (n = 11,997) were included. Compared to other sedatives, dexmedetomidine reduced the risk of delirium (RR 0.67, 95% CI 0.55 to 0.81; moderate certainty), the duration of mechanical ventilation (MD - 1.8 h, 95% CI  - 2.89 to  - 0.71; low certainty), and ICU length of stay (MD  - 0.32 days, 95% CI  - 0.42 to  - 0.22; low certainty). Dexmedetomidine use increased the risk of bradycardia (RR 2.39, 95% CI 1.82 to 3.13; moderate certainty) and hypotension (RR 1.32, 95% CI 1.07 to 1.63; low certainty). In mechanically ventilated adults, the use of dexmedetomidine compared to other sedatives, resulted in a lower risk of delirium, and a modest reduction in duration of mechanical ventilation and ICU stay, but increased the risks of bradycardia and hypotension.

Emerging Psychiatric Themes in Post-COVID-19 Patients on a Psychiatry Consultation-liaison Service

The need for consultation-liaison psychiatry on COVID-19 wards has substantially increased since the start of the pandemic. In this cross-sectional study, we aimed to summarize the characteristics of patients admitted to the post-COVID-19 ward of the American University of Beirut Medical Center who received a psychiatric consultation. We collected relevant sociodemographic and medical data, information about past psychiatric history, psychiatry consultation details, hospital course, and disposition outcome. We also conducted chi-square and binary logistic regression analyses to assess the association between the different variables and disposition outcome. A total of 52 patients (mean age 57.33 years; equal gender distribution) were seen by the psychiatry consult-liaison team. Most had medical comorbidities and 21.2% required intubation. The most prevalent psychiatric diagnoses were delirium (30.8%), major depressive episode (15.4%), and other anxiety disorder (15.4%). Pharmacological management was implemented in 90.4% of cases and mainly included second-generation antipsychotics (36.5%). Non-pharmacological interventions consisted of those related to delirium and therapy for anxiety. Only intubation was significantly associated with disposition outcome (p = 0.004). This study highlights the various psychiatric themes emerging during the acute and post-acute periods of hospitalization for COVID-19. Hospitalized individuals recovering from the infection should be diligently screened and referred to the psychiatry consultation-liaison team to ensure the implementation of appropriate interventions.

Sedation in the Intensive Care Unit

PURPOSE OF REVIEW

This narrative review illustrates literature over the last 5 years relating to sedation delivery to mechanically ventilated adult patients in intensive care units.

RECENT FINDINGS

There has been an increase in dexmedetomidine-related publications but although systematic reviews suggest dexmedetomidine reduces delirium, agitation, and length of stay, clinical trials have not supported these findings. It is likely to be useful for the managing patients with persisting agitation. Guidelines continue to recommend lightly sedating patients but considerable variation remains in clinical practice and in research trials. Protocols with no sedative infusions and morphine boluses as needed are feasible and safe, while educational interventions can decrease sedation-related adverse events.

SUMMARY

Research trials have mainly focused on individual drugs rather than practice. Given evidence is slow to translate into practice; work is needed to understand and respond to the concerns of clinicians regarding deep sedation and agitation.

Safety of dexmedetomidine for the control of agitation in critically ill traumatic brain injury patients: a descriptive study

BACKGROUND

Behavioural disturbances such as agitation are common following traumatic brain injury and can interfere with treatments, cause self-harm and delay rehabilitation. As there is a lack of evidence on the optimal approach to manage agitation in recovering TBI patients, various pharmacological agents are used including antipsychotics, anticonvulsants and sedative agents. Among sedatives, the safety and efficacy of dexmedetomidine to control agitation in traumatic brain injury patients is not well documented.

OBJECTIVE

To describe the safety, use and efficacy of dexmedetomidine for the management of agitation following traumatic brain injury in the intensive care unit.

METHODS

Medical records of all patients admitted to the intensive care unit of the Hôpital Sacré-Coeur de Montréal for a traumatic brain injury who received dexmedetomidine for agitation between 1 January 2017 and 31 December 2017 were reviewed. Patients who received dexmedetomidine for indications other than agitation were excluded. Data on dexmedetomidine prescription practices and safety were extracted. Frequency of agitation and concomitant psychoactive medication use was explored over a period starting two days prior to the initiation of dexmedetomidine to six days after or discontinuation, whichever came first.

RESULTS

We identified 41 patients in whom dexmedetomidine was initiated. Dexmedetomidine was started on median ICU day 3 (25^th -75^th percentiles: 2-7) and had a median treatment duration of 3 days (25^th -75^th percentiles: 3-6) and a mean average rate of 0.62 mcg/kg/h (SD 0.25). Although hypotension (76%) and bradycardia (54%) were common, only one patient required intervention. The proportion of patients with at least one episode of agitation decreased from 100% on day 0, to 88%, 69% and 63% on days 1, 2 and 3 of dexmedetomidine, respectively. The decrease was statistically significant difference between days 0 and 2 as well as between days 0 and 3. Concomitant use of propofol and benzodiazepines also decreased over the course of dexmedetomidine treatment.

CONCLUSION

Dexmedetomidine use was safe and associated with a reduction in agitation in traumatic brain injury patients in the 96 hours following its initiation.

Neuroprotective Effects of Dexmedetomidine Preconditioning on Oxygen-glucose Deprivation-reoxygenation Injury in PC12 Cells via Regulation of Ca2+-STIM1/Orai1 Signaling

Dexmedetomidine (DEX), a potent and highly selective agonist for α₂-adrenergic receptors (α₂AR), exerts neuroprotective effects by reducing apoptosis through decreased neuronal Ca²⁺ influx. However, the exact action mechanism of DEX and its effects on oxygen-glucose deprivation-reoxygenation (OGD/R) injury in vitro are unknown. We demonstrate that DEX pretreatment reduced OGD/R injury in PC12 cells, as evidenced by decreased oxidative stress, autophagy, and neuronal apoptosis. Specifically, DEX pretreatment decreased the expression levels of stromal interaction molecule 1 (STIM1) and calcium release-activated calcium channel protein 1 (Orai1), and reduced the concentration of intracellular calcium pools. In addition, variations in cytosolic calcium concentration altered apoptosis rate of PC12 cells after exposure to hypoxic conditions, which were modulated through STIM1/Orai1 signaling. Moreover, DEX pretreatment decreased the expression levels of Beclin-1 and microtubule-associated protein 1A/1B-light chain 3 (LC3), hallmark markers of autophagy, and the formation of autophagosomes. In conclusion, these results suggested that DEX exerts neuroprotective effects against oxidative stress, autophagy, and neuronal apoptosis after OGD/R injury via modulation of Ca²⁺-STIM1/Orai1 signaling. Our results offer insights into the molecular mechanisms of DEX in protecting against neuronal ischemia-reperfusion injury.

Dexmedetomidine for Facilitating Mechanical Ventilation Extubation in Difficult-to-Wean ICU Patients: Systematic Review and Meta-Analysis of Clinical Trials

BACKGROUND

Agitation and delirium are common in mechanically ventilated adult intensive care unit (ICU) patients and may contribute to delayed extubation times. Difficult-to-wean ICU patients have been associated with an increased risk of longer ICU length of stays and mortality. The purpose of this systematic review and meta-analysis is to evaluate the evidence of dexmedetomidine facilitating successful mechanical ventilation extubation in difficult-to-wean ICU patients and clinical outcomes.

METHODS

A literature search was conducted using MEDLINE, EMBASE, PsycINFO, Cumulative Index to Nursing and Allied Health Literature, Global Health, Cochrane Central Register of Controlled Trials, Clinical Trial Registries, and the Health Technology Assessment Database from inception to December 5, 2019. Randomized controlled trials evaluating dexmedetomidine with the intended purpose to facilitate mechanical ventilation liberation in adult ICU patients (≥18 years) experiencing extubation failure were included. The primary outcome of time to extubation was evaluated using the weighted mean difference (WMD), with a random effects model. Secondary analyses included hospital and ICU length of stay, in-hospital mortality, hypotension, and bradycardia.

RESULTS

A total of 6 trials (n = 306 patients) were included. Dexmedetomidine significantly reduced the time to extubation (WMD: -11.61 hours, 95% CI: -16.5 to -6.7, P = .005) and ICU length of stay (WMD: -3.04 days; 95% CI: -4.66 to -1.43). Hypotension risk was increased with dexmedetomidine (risk ratio [RR]: 1.62, 95% CI: 1.05-2.51), but there was no difference in bradycardia risk (RR: 3.98, 95% CI: 0.70-22.78). No differences were observed in mortality rates (RR: 1.30, 95% CI: 0.45-3.75) or hospital length of stay (WMD: -2.67 days; 95% CI: -7.73 to 2.39).

CONCLUSIONS

Dexmedetomidine was associated with a significant reduction in the time to extubation and shorter ICU stay in difficult-to-wean ICU patients. Although hypotension risk was increased with dexmedetomidine, no differences in other clinical outcomes were observed.