Alpha2 Agonist Use in Critically Ill Adults: A Focus on Sedation and Withdrawal Prevention

The management of sedation in critically ill adults poses a unique challenge to clinicians. Dexmedetomidine, an α2 agonist, has a unique mechanism and favorable pharmacokinetics, making it an attractive intravenous option for sedation and delirium in the intensive care unit. However, patients may be at risk for withdrawal with prolonged use, adding to the complexity of sedation and agitation management in this patient population. Enteral α2 agents have the benefit of cost savings and ease of administration, thus playing a role in the ability to decrease intravenous sedative use and prevent dexmedetomidine withdrawal. Clonidine and guanfacine are the two most common enteral α2 agents utilized for this purpose, however, there is a paucity of evidence regarding the comparative benefit between the two agents. The decision to use one vs the other agent should be determined based on their differing pharmacology, pharmacokinetics, and side effect profile. The most effective dosing strategy for these agents is also unknown. Ultimately, more robust literature is required to determine enteral α2 agonists place in therapy. This narrative review evaluates the currently available literature on the use of α2 agonists in critically ill adults with an emphasis on sedation, delirium, and withdrawal.

Relative band power in assessing temporary neurological dysfunction post- type A aortic dissection surgery: a prospective study

Temporary neurological dysfunction (TND), a common complication following surgical repair of Type A Aortic Dissection (TAAD), is closely associated with increased mortality and long-term cognitive impairment. Currently, effective treatment options for TND remain elusive. Therefore, we sought to investigate the potential of postoperative relative band power (RBP) in predicting the occurrence of postoperative TND, with the aim of identifying high-risk patients prior to the onset of TND. We conducted a prospective observational study between February and December 2022, involving 165 patients who underwent surgical repair for TAAD at our institution. Bedside Quantitative electroencephalography (QEEG) was utilized to monitor the post-operative brain electrical activity of each participant, recording changes in RBP (RBP Delta, RBP Theta, RBP Beta and RBP Alpha), and analyzing their correlation with TND. Univariate and multivariate analyses were employed to identify independent risk factors for TND. Subsequently, line graphs were generated to estimate the incidence of TND. The primary outcome of interest was the development of TND, while secondary outcomes included intensive care unit (ICU) admission and length of hospital stay. A total of 165 patients were included in the study, among whom 68 (41.2%) experienced TND. To further investigate the independent risk factors for postoperative TND, we conducted both univariate and multivariate logistic regression analyses on all variables. In the univariate regression analysis, we identified age (Odds Ratio [OR], 1.025; 95% CI, 1.002-1.049), age ≥ 60 years (OR, 2.588; 95% CI, 1.250-5.475), hemopericardium (OR, 2.767; 95% CI, 1.150-7.009), cardiopulmonary bypass (CPB) (OR, 1.007; 95% CI, 1.001-1.014), RBP Delta (OR, 1.047; 95% CI, 1.020-1.077), RBP Alpha (OR, 0.853; 95% CI, 0.794-0.907), and Beta (OR, 0.755; 95% CI, 0.649-0.855) as independent risk factors for postoperative TND. Further multivariate regression analyses, we discovered that CPB time ≥ 180 min (OR, 1.021; 95% CI, 1.011-1.032), RBP Delta (OR, 1.168; 95% CI, 1.105-1.245), and RBP Theta (OR, 1.227; 95% CI, 1.135-1.342) emerged as independent risk factors. TND patients had significantly longer ICU stays (p < 0.001), and hospital stays (p = 0.002). We obtained the simplest predictive model for TND, consisting of three variables (CPB time ≥ 180 min, RBP Delta, RBP Theta, upon which we constructed column charts. The areas under the receiver operating characteristic (AUROC) were 0.821 (0.755, 0.887). Our study demonstrates that postoperative RBP monitoring can detect changes in brain function in patients with TAAD during the perioperative period, providing clinicians with an effective predictive method that can help improve postoperative TND in TAAD patients. These findings have important implications for improving clinical care in this population.Trial registration ChiCTR2200055980. Registered 30th Jan. 2022. This trial was registered before the first participant was enrolled.

Efficacy and safety of subcutaneous clonidine for refractory symptoms in palliative medicine: a retrospective study

OBJECTIVES

To investigate the efficacy and safety of subcutaneous clonidine for refractory symptoms in the palliative setting.

METHODS

A retrospective chart review of the use of subcutaneous clonidine in a single palliative care centre. We reviewed the use of clonidine since it was introduced in our locality 2½ years ago. All clinical notes, medication administration records and infusion monitoring documentation were examined to ascertain therapeutic aim, efficacy and tolerability.

RESULTS

Subcutaneous clonidine was administered to 113 patients. Recipients were generally frail (median Karnofsky Score 20%) and in the last weeks of life (median survival 6 days). The the most common indications were opioid poorly responsive pain (59), agitation refractory to antipsychotics and/or benzodiazepines (18) or both (35). Symptoms appeared to improve in the majority (85/113, 75%). Some (36, 32%) required no further medication changes once clonidine was commenced. Clonidine appeared well tolerated although blood pressure was not monitored in the majority, in line with our practice to discontinue such observations in those who are nursed in bed and receiving symptom-focused care.

CONCLUSIONS

Subcutaneous administration of clonidine appears to be a promising alternative option for refractory symptoms in the last weeks of life. We suggest some possible next steps for further research.

Pharmacological prevention of postoperative delirium in patients undergoing cardiac surgery: a bayesian network meta-analysis

The incidence of postoperative delirium in patients undergoing cardiac surgery is very high and increases morbidity and mortality. The possibility of pharmacological means to reduce its incidence is very attractive. At present, there is still no clear demonstration that any drug can prevent postoperative delirium in these patients. The aim of this Bayesian network meta-analysis (NMA) was to evaluate whether there is evidence that a drug is effective in reducing the incidence of POD in cardiac surgical patients. Our NMA showed that preoperative ketamine at subanesthetic doses can significantly reduce the incidence of POD. Risperidone also decreases the incidence of POD, but not significantly.

Pharmacologic Management of Delirium in the Intensive Care Unit

Delirium, often underdiagnosed in the intensive care unit, is a common complication of critical illness that contributes to significant morbidity and mortality. Clinicians should be aware of common risk factors and triggers and should work to mitigate these as much as possible to reduce the occurrence of delirium. This review first provides an overview of the epidemiology, pathophysiology, evaluation, and consequences of delirium in critically ill patients. Presented next is the current evidence for the pharmacologic management of delirium, focusing on prevention and treatment of delirium in the intensive care unit. It concludes by outlining some emerging treatments of delirium.

Alpha-2-adrenergic receptor agonists for the prevention of delirium and cognitive decline after open heart surgery (ALPHA2PREVENT): protocol for a multicentre randomised controlled trial

INTRODUCTION

Postoperative delirium is common in older cardiac surgery patients and associated with negative short-term and long-term outcomes. The alpha-2-adrenergic receptor agonist dexmedetomidine shows promise as prophylaxis and treatment for delirium in intensive care units (ICU) and postoperative settings. Clonidine has similar pharmacological properties and can be administered both parenterally and orally. We aim to study whether repurposing of clonidine can represent a novel treatment option for delirium, and the possible effects of dexmedetomidine and clonidine on long-term cognitive trajectories, motor activity patterns and biomarkers of neuronal injury, and whether these effects are associated with frailty status.

METHODS AND ANALYSIS

This five-centre, double-blind randomised controlled trial will include 900 cardiac surgery patients aged 70+ years. Participants will be randomised 1:1:1 to dexmedetomidine or clonidine or placebo. The study drug will be given as a continuous intravenous infusion from the start of cardiopulmonary bypass, at a rate of 0.4 µg/kg/hour. The infusion rate will be decreased to 0.2 µg/kg/hour postoperatively and be continued until discharge from the ICU or 24 hours postoperatively, whichever happens first.Primary end point is the 7-day cumulative incidence of postoperative delirium (Diagnostic and Statistical Manual of Mental Disorders, fifth edition). Secondary end points include the composite end point of coma, delirium or death, in addition to delirium severity and motor activity patterns, levels of circulating biomarkers of neuronal injury, cognitive function and frailty status 1 and 6 months after surgery.

ETHICS AND DISSEMINATION

This trial is approved by the Regional Committee for Ethics in Medical Research in Norway (South-East Norway) and by the Norwegian Medicines Agency. Dissemination plans include publication in peer-reviewed medical journals and presentation at scientific meetings.

TRIAL REGISTRATION NUMBER

NCT05029050.

Use of continuous infusion of clonidine for sedation in critically ill infants and children

BACKGROUND

Adequate sedation and analgesia are required for critically ill children in order to minimize discomfort, reduce anxiety, and facilitate care. This is commonly achieved through a combination of opioids and benzodiazepines. Prolonged use of these agents is associated with tolerance and withdrawal. Clonidine as an adjunctive sedative agent may reduce sedation-related adverse events.

OBJECTIVE

Our first aim was to describe the indication for clonidine administration and its secondary effects in a mixed cohort of critically ill children. Our secondary aim was to measure the consumption of sedatives during two study periods: before and after the use of clonidine in our pediatric intensive care unit (PICU).

METHODS

This was a single-center study conducted in a tertiary PICU and encompassed retrospective chart review of patients who received clonidine between November 2013 and April 2015. We collected data on clonidine dosage, duration of administration, indication for the prescription, and potential side effects. We analyzed the total consumption of sedatives over 18 months, before and after the introduction of clonidine in our sedation protocol.

RESULTS

A total of patients received clonidine, with a mean age of 2.2 ± 2.8 years. The primary reason for intensive care admission was respiratory failure (48%). The main indication for clonidine administration was increasing requirement for morphine and midazolam (60%). The mean duration of clonidine infusion was 9 ± 7.3 days. Bradycardia and hypotension occurred in five patients (11.6%) and nine patients (21%), respectively. These side effects did not result in any major intervention. Younger age was a risk factor for clonidine-associated bradycardia. We observed a significant decrease in morphine and midazolam consumption with clonidine as a comedication. Compared with the pre-study period, consumption decreased by 19.7% for morphine and by 59% for midazolam (calculated as milligram/admission).

CONCLUSION

Continuous infusion of clonidine in critically ill children is safe and effective. Clonidine is a sedative-sparing agent and this can help reduce complications associated with prolonged use of opioids and benzodiazepines.

Renal and Cerebral Hypoxia and Inflammation During Cardiopulmonary Bypass

Cardiac surgery-associated acute kidney injury and brain injury remain common despite ongoing efforts to improve both the equipment and procedures deployed during cardiopulmonary bypass (CPB). The pathophysiology of injury of the kidney and brain during CPB is not completely understood. Nevertheless, renal (particularly in the medulla) and cerebral hypoxia and inflammation likely play critical roles. Multiple practical factors, including depth and mode of anesthesia, hemodilution, pump flow, and arterial pressure can influence oxygenation of the brain and kidney during CPB. Critically, these factors may have differential effects on these two vital organs. Systemic inflammatory pathways are activated during CPB through activation of the complement system, coagulation pathways, leukocytes, and the release of inflammatory cytokines. Local inflammation in the brain and kidney may be aggravated by ischemia (and thus hypoxia) and reperfusion (and thus oxidative stress) and activation of resident and infiltrating inflammatory cells. Various strategies, including manipulating perfusion conditions and administration of pharmacotherapies, could potentially be deployed to avoid or attenuate hypoxia and inflammation during CPB. Regarding manipulating perfusion conditions, based on experimental and clinical data, increasing standard pump flow and arterial pressure during CPB appears to offer the best hope to avoid hypoxia and injury, at least in the kidney. Pharmacological approaches, including use of anti-inflammatory agents such as dexmedetomidine and erythropoietin, have shown promise in preclinical models but have not been adequately tested in human trials. However, evidence for beneficial effects of corticosteroids on renal and neurological outcomes is lacking. © 2021 American Physiological Society. Compr Physiol 11:1-36, 2021.

Construction and Application of a Model for Predicting the Risk of Delirium in Postoperative Patients With Type a Aortic Dissection

Background: Postoperative delirium (POD), an alteration in a patient's consciousness pattern, can affect the treatment and prognosis of a disease.

Objective: To construct a prediction model for delirium in patients with type A aortic dissection after surgery and to validate its effectiveness.

Methods: A retrospective cohort design was used to study 438 patients undergoing surgical treatment for type A aortic dissection from April 2019 to June 2020 in tertiary care hospitals. POD (n = 78) and non-delirium groups (n = 360) were compared and analyzed for each index in the perioperative period. A prediction model was established using multifactorial logistic regression, and 30 patients' perioperative data were collected for model validation.

Results: Eight predictors were included in this study: smoking, diabetes, previous cardiovascular surgery, ejection fraction (EF), time to aortic block, acute kidney injury, low cardiac output syndrome, and pulmonary complications. The area under the receiver operating characteristic (ROC) curve of the constructed prediction model was 0.98 ± 0.005, and the Youden index was 0.91. The validation results showed 97% sensitivity, 100% specificity, and 93% accuracy. The expression of the model was Z = Smoking assignment^* – 2.807 – 6.009^*Diabetes assignment – 2.994^*Previous cardiovascular surgery assignment – 0.129^*Ejection fraction assignment + 0.071^*Brain perfusion time assignment – 2.583^*Acute kidney injury assignment – 2.916^*Low cardiac output syndrome assignment – 3.461^*Pulmonary related complications assignment + 20.576.

Conclusion: The construction of an effective prediction model for the risk of delirium in patients after type A aortic stratification can help identify patients at high risk of POD early. It also provides a reference for healthcare professionals in the prevention and care of these patients.

Effects of Intraoperative Dexmedetomidine Infusion on Postoperative Delirium in Elderly Patients Undergoing Total Hip Arthroplasty

Objective

To investigate the effects of dexmedetomidine on postoperative delirium in elderly patients undergoing total hip arthroplasty.

Methods

A total of 100 patients, 42 male and 58 female, ages 60 to 85 years, American Society of Anesthesiologists grade I or II, who were undergoing total hip arthroplasty were randomly divided into 2 groups: a dexmedetomidine group (group D; n = 50) and a control group (group C; n = 50). Group D patients were infused with 0.3 μg · kg−1 · h−1 of dexmedetomidine from 5 minutes prior to anesthesia induction until the end of surgery. Group C patients received an equal volume of saline. Heart rate and mean arterial pressure (MAP) were recorded before anesthesia induction (T0), 1 minute before extubation (T1), and 30 minutes after extubation (T2). The Visual Analog Score (VAS) at 1, 2, and 3 days after surgery, the incidence and duration of postoperative delirium, and the length of hospital stay were recorded. Adverse reactions, such as nausea, vomiting, and lethargy, were also recorded.

Results

The Visual Analog Scores in the 2 groups were similar. In group D, there was no significant difference in heart rate (P = 0.232) and MAP (P = 0.056) between T0 and T1. However, in group C, heart rate significantly increased by 15.3 bpm (P = 0.000) and MAP significantly increased by 10.7 mmHg (P = 0.001) at T1 compared with those at T0. The incidence of postoperative delirium in group D (10%) was significantly lower than that in group C (26%; P = 0.037). The duration of delirium in group D (1.3 ± 0.6 days) was shorter than that in group C (3.0 ± 0.5 days; P = 0.000). The length of hospital stay in group D (13.2 ± 0.9 days) was shorter than that in group C (16.1 ± 0.7 days; P = 0.000). No significant differences were observed in adverse effects between the 2 groups.

Conclusion

Intravenous infusion of dexmedetomidine can not only reduce the incidence and duration of postoperative delirium, but also shorten the length of hospital stay in elderly patients undergoing total hip arthroplasty.

High sedation needs of critically ill COVID-19 ARDS patients-A monocentric observational study

BACKGROUND

Therapy of severely affected coronavirus patient, requiring intubation and sedation is still challenging. Recently, difficulties in sedating these patients have been discussed. This study aims to describe sedation practices in patients with 2019 coronavirus disease (COVID-19)-induced acute respiratory distress syndrome (ARDS).

METHODS

We performed a retrospective monocentric analysis of sedation regimens in critically ill intubated patients with respiratory failure who required sedation in our mixed 32-bed university intensive care unit. All mechanically ventilated adults with COVID-19-induced ARDS requiring continuously infused sedative therapy admitted between April 4, 2020, and June 30, 2020 were included. We recorded demographic data, sedative dosages, prone positioning, sedation levels and duration. Descriptive data analysis was performed; for additional analysis, a logistic regression with mixed effect was used.

RESULTS

In total, 56 patients (mean age 67 (±14) years) were included. The mean observed sedation period was 224 (±139) hours. To achieve the prescribed sedation level, we observed the need for two or three sedatives in 48.7% and 12.8% of the cases, respectively. In cases with a triple sedation regimen, the combination of clonidine, esketamine and midazolam was observed in most cases (75.7%). Analgesia was achieved using sufentanil in 98.6% of the cases. The analysis showed that the majority of COVID-19 patients required an unusually high sedation dose compared to those available in the literature.

CONCLUSION

The global pandemic continues to affect patients severely requiring ventilation and sedation, but optimal sedation strategies are still lacking. The findings of our observation suggest unusual high dosages of sedatives in mechanically ventilated patients with COVID-19. Prescribed sedation levels appear to be achievable only with several combinations of sedatives in most critically ill patients suffering from COVID-19-induced ARDS and a potential association to the often required sophisticated critical care including prone positioning and ECMO treatment seems conceivable.

Effects of perioperative interventions for preventing postoperative delirium: A protocol for systematic review and meta-analysis of randomized controlled trials

BACKGROUND

Postoperative delirium (POD) not only increases the medical burden but also adversely affects patient prognosis. Although some cases of delirium can be avoided by early intervention, there is no clear evidence indicating whether any of these measures can effectively prevent POD in specific patient groups.

OBJECTIVE

The aim of this meta-analysis was to compare the efficacy and safety of the existing preventive measures for managing POD.

METHODS

The PubMed, OVID (Embase and MEDLINE), Web of Science, and the Cochrane Library databases were searched for articles published before January 2020. The relevant randomized controlled trials (RCTs) were selected based on the inclusion and exclusion criteria. Data extraction and methodological quality assessment were performed according to a predesigned data extraction form and scoring system, respectively. The interventions were compared on the basis of the primary outcome like incidence of POD, and secondary outcomes like duration of delirium and the length of intensive care unit and hospital stay.

RESULTS

Sixty-three RCTs were included in the study, covering interventions like surgery, anesthesia, analgesics, intraoperative blood glucose control, cholinesterase inhibitors, anticonvulsant drugs, antipsychotic drugs, sleep rhythmic regulation, and multi-modal nursing. The occurrence of POD was low in 4 trials that monitored the depth of anesthesia with bispectral index during the operation (P < .0001). Two studies showed that supplementary analgesia was useful for delirium prevention (P = .002). Seventeen studies showed that perioperative sedation with α2-adrenergic receptor agonists prevented POD (P = .0006). Six studies showed that both typical and atypical antipsychotic drugs can reduce the incidence of POD (P = .002). Multimodal nursing during the perioperative period effectively reduced POD in 6 studies (P < .00001). Furthermore, these preventive measures can reduce the duration of delirium, as well as the total and postoperative length of hospitalized stay for non-cardiac surgery patients. For patients undergoing cardiac surgery, effective prevention can only reduce the length of intensive care unit stay.

CONCLUSION

Measures including intraoperative monitoring of bispectral index, supplemental analgesia, α2-adrenergic receptor agonists, antipsychotic drugs, and multimodal care are helpful to prevent POD effectively. However, larger, high-quality RCTs are needed to verify these findings and develop more interventions and drugs for preventing postoperative delirium.

Comparative effectiveness of pharmacological interventions to prevent postoperative delirium: a network meta-analysis

Many pharmacologic agents were investigated for the effect to prevent delirium. We aimed to comprehensively compare the effect of the pharmacological interventions to prevent postoperative delirium. A Bayesian network meta-analysis of randomized trials was performed using random effects model. PubMed, the Cochrane Central Register of Controlled Trials, and Embase were searched on 20 January 2021. Randomized trials comparing the effect of a drug to prevent postoperative delirium with another drug or placebo in adult patients undergoing any kind of surgery were included. Primary outcome was the postoperative incidence of delirium. Eighty-six trials with 26,992 participants were included. Dexmedetomidine, haloperidol, and atypical antipsychotics significantly decreased the incidence of delirium than placebo [dexmedetomidine: odds ratio 0.51, 95% credible interval (CrI) 0.40-0.66, moderate quality of evidence (QOE); haloperidol: odds ratio 0.59, 95% CrI 0.37-0.95, moderate QOE; atypical antipsychotics: odds ratio 0.27, 95% CrI 0.14-0.51, moderate QOE]. Dexmedetomidine and atypical antipsychotics had the highest-ranking probabilities to be the best. However, significant heterogeneity regarding diagnostic time window as well as small study effects precludes firm conclusion.

Haloperidol, clonidine and resolution of delirium in critically ill patients: a prospective cohort study

Purpose

Haloperidol and clonidine are commonly used to treat agitation in delirious intensive care unit (ICU) patients, but it is unclear whether these agents may shorten the duration of delirium. The objective of this study was to determine whether haloperidol, clonidine, or their combined administration to delirious ICU patients results in delirium resolution.

Methods

This was a cohort study on a mixed ICU, excluding patients with a primary neurological disorder. The main outcome was the probability of delirium resolution, using propensity score matching and Markov multinomial logistic regression models for daily transitions. Secondary outcomes were delirium duration, number of delirium days, ventilation days, length of stay in the ICU and hospital, and ICU mortality.

Results

A total of 3614 patients were included (1165 delirious [32%]; 2449 non-delirious [68%]). Delirium occurred on 4708 (18.9%) of 24,906 days. The probability of delirium resolution was lower in delirious patients who received haloperidol (OR 0.47, 95% CI 0.39–0.57), clonidine (OR 0.78, 95% CI 0.63–0.97), or both (OR 0.45, 95% CI 0.36–0.56) compared to untreated delirious patients. Delirious patients who received haloperidol, clonidine, or both had generally longer delirium duration, more delirium and ventilation days, and spent more time in the ICU and in hospital than untreated delirious patients. These agents had no effect on ICU mortality.

Conclusion

Haloperidol and clonidine use in delirious ICU patients may be associated with reduced probability of delirium resolution. This finding, however, merits further investigation given inherent limitations of this observational analysis.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00134-021-06355-9.

Pharmacological and non-pharmacological interventions to prevent delirium in critically ill patients: a systematic review and network meta-analysis

PURPOSE

To compare the effects of prevention interventions on delirium occurrence in critically ill adults.

METHODS

MEDLINE, Embase, PsychINFO, CINAHL, Web of Science, Cochrane Library, Prospero, and WHO international clinical trial registry were searched from inception to April 8, 2021. Randomized controlled trials of pharmacological, sedation, non-pharmacological, and multi-component interventions enrolling adult critically ill patients were included. We performed conventional pairwise meta-analyses, NMA within Bayesian random effects modeling, and determined surface under the cumulative ranking curve values and mean rank. Reviewer pairs independently extracted data, assessed bias using Cochrane Risk of Bias tool and evidence certainty with GRADE. The primary outcome was delirium occurrence; secondary outcomes were durations of delirium and mechanical ventilation, length of stay, mortality, and adverse effects.

RESULTS

Eighty trials met eligibility criteria: 67.5% pharmacological, 31.3% non-pharmacological and 1.2% mixed pharmacological and non-pharmacological interventions. For delirium occurrence, 11 pharmacological interventions (38 trials, N = 11,993) connected to the evidence network. Compared to placebo, only dexmedetomidine (21/22 alpha₂ agonist trials were dexmedetomidine) probably reduces delirium occurrence (odds ratio (OR) 0.43, 95% Credible Interval (CrI) 0.21-0.85; moderate certainty). Compared to benzodiazepines, dexmedetomidine (OR 0.21, 95% CrI 0.08-0.51; low certainty), sedation interruption (OR 0.21, 95% CrI 0.06-0.69; very low certainty), opioid plus benzodiazepine (OR 0.27, 95% CrI 0.10-0.76; very low certainty), and protocolized sedation (OR 0.27, 95% CrI 0.09-0.80; very low certainty) may reduce delirium occurrence but the evidence is very uncertain. Dexmedetomidine probably reduces ICU length of stay compared to placebo (Ratio of Means (RoM) 0.78, CrI 0.64-0.95; moderate certainty) and compared to antipsychotics (RoM 0.76, CrI 0.61-0.98; low certainty). Sedative interruption, protocolized sedation and opioids may reduce hospital length of stay compared to placebo, but the evidence is very uncertain. No intervention influenced mechanical ventilation duration, mortality, or arrhythmia. Single and multi-component non-pharmacological interventions did not connect to any evidence networks to allow for ranking and comparisons as planned; pairwise comparisons did not detect differences compared to standard care.

CONCLUSION

Compared to placebo and benzodiazepines, we found dexmedetomidine likely reduced the occurrence of delirium in critically ill adults. Compared to benzodiazepines, sedation-minimization strategies may also reduce delirium occurrence, but the evidence is uncertain.

Medication Safety in Intravenous Therapy: A Compatibility Study of Clonidine with Drugs Frequently Used in Intensive Care

The intravenous pharmacotherapy of critically ill patients is extremely challenging due to the high number of drugs administered. We therefore evaluated the physicochemical compatibility of combinations of clonidine with drugs frequently used in an intensive care unit setting. Amiodarone, dihydralazine, furosemide, levosimendan, metamizole, milrinone, urapidil, and verapamil were each prepared as binary combinations with clonidine at the standard low and high administration concentrations. Selected ternary combinations were also analyzed. Samples were examined for physical compatibility. To verify chemical compatibility in samples deemed either physically compatible or to exhibit uncertain results, the drug content was quantified using high-performance liquid chromatography. Admixtures of clonidine with amiodarone or furosemide proved to be physically incompatible, whereas mixtures with levosimendan and metamizole exhibited results, which were not clearly meeting the specification criteria for physical compatibility. Binary combinations of clonidine with dihydralazine, milrinone, urapidil, and verapamil were found to be physically compatible. Combinations with dihydralazine, levosimendan, metamizole, milrinon, urapidil, or verapamil were chemically compatible for the analyzed concentrations. Ternary admixtures of clonidine, metamizole, and urapidil; clonidine, metamizole, and verapamil; clonidine, urapidil, and verapamil were shown to be physicochemically compatible for the analyzed concentrations. These data suggest that clonidine can be coadministered with dihydralazine, levosimendan, metamizole, milrinone, urapidil, and verapamil. However, the concomitant administration of clonidine with amiodarone or furosemide is not recommended.

Neurocovid: Pharmacological Recommendations for Delirium Associated With COVID-19

BACKGROUND

The pandemic of coronavirus disease 2019 (COVID-19) caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has emerged as one of the biggest health threats of our generation. A significant portion of patients are presenting with delirium and neuropsychiatric sequelae of the disease. Unique examination findings and responses to treatment have been identified.

OBJECTIVE

In this article, we seek to provide pharmacologic and treatment recommendations specific to delirium in patients with COVID-19.

METHODS

We performed a literature search reviewing the neuropsychiatric complications and treatments in prior coronavirus epidemics including Middle Eastern respiratory syndrome and severe acute respiratory syndrome coronaviruses, as well as the emerging literature regarding COVID-19. We also convened a work group of consultation-liaison psychiatrists actively managing patients with COVID-19 in our hospital. Finally, we synthesized these findings to provide preliminary pharmacologic recommendations for treating delirium in these patients.

RESULTS

Delirium is frequently found in patients who test positive for COVID-19, even in the absence of respiratory symptoms. There appears to be a higher rate of agitation, myoclonus, abulia, and alogia. No data are currently available on the treatment of delirium in patients with COVID-19. Extrapolating from general delirium treatment, Middle Eastern respiratory syndrome/severe acute respiratory syndrome case reports, and our experience, preliminary recommendations for pharmacologic management have been assembled.

CONCLUSIONS

COVID-19 is associated with neuropsychiatric symptoms. Low-potency neuroleptics and alpha-2 adrenergic agents may be especially useful in this setting. Further research into the pathophysiology of COVID-19 will be key in developing more targeted treatment guidelines.

Optimising the dose of clonidine to achieve sedation in intensive care unit patients with population pharmacokinetics

Aims

The aim of this study was to investigate the population pharmacokinetics (PK) of clonidine in intensive care unit (ICU) patients in order to develop a dosing regimen for sedation.

Methods

We included 24 adult mechanically ventilated, sedated patients from a mixed medical and surgical ICU. Intravenous clonidine was added to standard sedation in doses of 600, 1200 or 1800 μg/d. Within each treatment group, 4 patients received a loading dose of half the daily dose administered in 4 hours. Patients gave an average of 12 samples per individual. In total, 286 samples were available for analysis. Model development was conducted with NONMEM and various covariates were tested. After modelling, doses to achieve a target steady‐state plasma concentration of >1.5 μg/L were explored using stochastic Monte Carlo simulations for 1000 virtual patients.

Results

A 2‐compartment model was the best fit for the concentration‐time data. Clearance (CL) increased linearly with 0.213%/h; using allometric scaling, body weight was a significant covariate on the central volume of distribution (V1). Population PK parameters were: CL 17.1 (L/h), V1 124 (L/70 kg), intercompartmental CL 83.7 (L/h), and peripheral volume of distribution 178 (L), with 33.3% CV interindividual variability on CL and 66.8% CV interindividual variability on V1. Simulations revealed that a maintenance dose of 1200 μg/d provides target sedation concentrations of >1.5 μg/L in 95% of the patients.

Conclusion

A population PK model for clonidine was developed in an adult ICU. A dosing regimen of 1200 μg/d provided a target sedation concentration of >1.5 μg/L.

Pharmacological interventions for the treatment of delirium in critically ill adults

BACKGROUND

Although delirium is typically an acute reversible cognitive impairment, its presence is associated with devastating impact on both short-term and long-term outcomes for critically ill patients. Advances in our understanding of the negative impact of delirium on patient outcomes have prompted trials evaluating multiple pharmacological interventions. However, considerable uncertainty surrounds the relative benefits and safety of available pharmacological interventions for this population.

OBJECTIVES

Primary objective1. To assess the effects of pharmacological interventions for treatment of delirium on duration of delirium in critically ill adults with confirmed or documented high risk of deliriumSecondary objectivesTo assess the following:1. effects of pharmacological interventions on delirium-free and coma-free days; days with coma; delirium relapse; duration of mechanical ventilation; intensive care unit (ICU) and hospital length of stay; mortality; and long-term outcomes (e.g. cognitive; discharge disposition; health-related quality of life); and2. the safety of such treatments for critically ill adult patients.

SEARCH METHODS

We searched the following databases from their inception date to 21 March 2019: Ovid MEDLINE®, Ovid MEDLINE® In-Process & Other Non-Indexed Citations, Embase Classic+Embase, and PsycINFO using the Ovid platform. We also searched the Cochrane Library on Wiley, the International Prospective Register of Systematic Reviews (PROSPERO) (http://www.crd.york.ac.uk/PROSPERO/), the Cumulative Index to Nursing and Allied Health Literature (CINAHL), and Web of Science. We performed a grey literature search of relevant databases and websites using the resources listed in Grey Matters developed by the Canadian Agency for Drugs and Technologies in Health (CADTH). We also searched trial registries and abstracts from annual scientific critical care and delirium society meetings.

SELECTION CRITERIA

We sought randomized controlled trials (RCTs), including quasi-RCTs, of any pharmacological (drug) for treatment of delirium in critically ill adults. The drug intervention was to be compared to another active drug treatment, placebo, or a non-pharmacological intervention (e.g. mobilization). We did not apply any restrictions in terms of drug class, dose, route of administration, or duration of delirium or drug exposure. We defined critically ill patients as those treated in an ICU of any specialty (e.g. burn, cardiac, medical, surgical, trauma) or high-dependency unit.

DATA COLLECTION AND ANALYSIS

Two review authors independently identified studies from the search results; four review authors (in pairs) performed data extraction and assessed risk of bias independently. We performed data synthesis through pairwise meta-analysis and network meta-analysis (NMA). Our hypothetical network structure was designed to be analysed at the drug class level and illustrated a network diagram of 'nodes' (i.e. drug classes) and 'edges' (i.e. comparisons between different drug classes from existing trials), thus describing a treatment network of all possible comparisons between drug classes. We assessed the quality of the body of evidence according to GRADE, as very low, low, moderate, or high.

MAIN RESULTS

We screened 7674 citations, from which 14 trials with 1844 participants met our inclusion criteria. Ten RCTs were placebo-controlled, and four reported comparisons of different drugs. Drugs examined in these trials were the following: antipsychotics (n = 10), alpha2 agonists (n = 3; all dexmedetomidine), statins (n = 2), opioids (n = 1; morphine), serotonin antagonists (n = 1; ondansetron), and cholinesterase (CHE) inhibitors (n = 1; rivastigmine). Only one of these trials consistently used non-pharmacological interventions that are known to improve patient outcomes in both intervention and control groups.Eleven studies (n = 1153 participants) contributed to analysis of the primary outcome. Results of the NMA showed that the intervention with the smallest ratio of means (RoM) (i.e. most preferred) compared with placebo was the alpha2 agonist dexmedetomidine (0.58; 95% credible interval (CrI) 0.26 to 1.27; surface under the cumulative ranking curve (SUCRA) 0.895; moderate-quality evidence). In order of descending SUCRA values (best to worst), the next best interventions were atypical antipsychotics (RoM 0.80, 95% CrI 0.50 to 1.11; SUCRA 0.738; moderate-quality evidence), opioids (RoM 0.88, 95% CrI 0.37 to 2.01; SUCRA 0.578; very-low quality evidence), and typical antipsychotics (RoM 0.96, 95% CrI 0.64 to1.36; SUCRA 0.468; high-quality evidence).The NMAs of multiple secondary outcomes revealed that only the alpha2 agonist dexmedetomidine was associated with a shorter duration of mechanical ventilation (RoM 0.55, 95% CrI 0.34 to 0.89; moderate-quality evidence), and the CHE inhibitor rivastigmine was associated with a longer ICU stay (RoM 2.19, 95% CrI 1.47 to 3.27; moderate-quality evidence). Adverse events often were not reported in these trials or, when reported, were rare; pair-wise analysis of QTc prolongation in seven studies did not show significant differences between antipsychotics, ondansetron, dexmedetomidine, and placebo.

AUTHORS' CONCLUSIONS

We identified trials of varying quality that examined six different drug classes for treatment of delirium in critically ill adults. We found evidence that the alpha2 agonist dexmedetomidine may shorten delirium duration, although this small effect (compared with placebo) was seen in pairwise analyses based on a single study and was not seen in the NMA results. Alpha2 agonists also ranked best for duration of mechanical ventilation and length of ICU stay, whereas the CHE inhibitor rivastigmine was associated with longer ICU stay. We found no evidence of a difference between placebo and any drug in terms of delirium-free and coma-free days, days with coma, physical restraint use, length of stay, long-term cognitive outcomes, or mortality. No studies reported delirium relapse, resolution of symptoms, or quality of life. The ten ongoing studies and the six studies awaiting classification that we identified, once published and assessed, may alter the conclusions of the review.

State of the clinical science of perioperative brain health: report from the American Society of Anesthesiologists Brain Health Initiative Summit 2018

Cognitive recovery after anaesthesia and surgery is a concern for older adults, their families, and caregivers. Reports of patients who were 'never the same' prompted a scientific inquiry into the nature of what patients have experienced. In June 2018, the ASA Brain Health Initiative held a summit to discuss the state of the science on perioperative cognition, and to create an implementation plan for patients and providers leveraging the current evidence. This group included representatives from the AARP (formerly the American Association of Retired Persons), American College of Surgeons, American Heart Association, and Alzheimer's Association Perioperative Cognition and Delirium Professional Interest Area. This paper summarises the state of the relevant clinical science, including risk factors, identification and diagnosis, prognosis, disparities, outcomes, and treatment of perioperative neurocognitive disorders. Finally, we discuss gaps in current knowledge with suggestions for future directions and opportunities for clinical and translational projects.

The Oslo Study of Clonidine in Elderly Patients with Delirium; LUCID: a randomised placebo-controlled trial

OBJECTIVES

The aim of this double-blinded randomised placebo-controlled trial was to investigate the efficacy of clonidine for delirium in medical inpatients greater than 65 years.

METHODS

Acutely admitted medical patients greater than 65 years with delirium or subsyndromal delirium were eligible for inclusion. Included patients were given a loading dose of either placebo or clonidine; 75 μg every third hour up to a maximum of four doses to reach steady state and further 75 μg twice daily until delirium free for 2 days, discharge or a maximum of 7 days of treatment. The primary endpoint was the trajectory of the Memorial Delirium Assessment Scale (MDAS) for the 7 days of treatment. Presence of delirium according to the Diagnostic and Statistical Manual of Mental Disorders (DSM-5) criteria and severity measured by MDAS were assessed daily until discharge or a maximum of 7 days after end of treatment.

RESULTS

Because of slower enrolment than anticipated, the study was halted early. Ten patients in each group were studied. The low recruitment rate was mainly due to the presence of multiple patient exclusion criteria for patient safety. There was no significant difference between the treatment group in the primary endpoint comparing the trajectory of MDAS for the 7 days of treatment using mixed linear models with log transformation, (P = .60). The treatment group did not have increased adverse effects.

CONCLUSIONS

No effect of clonidine for delirium was found, although the study was under powered. Further studies in less frail populations are now required.

Risk Factors for Postoperative Delirium in Type A Aortic Dissection Patients: A Retrospective Study

BACKGROUND Postoperative delirium (POD) is a common complication in cardiac surgery among adult patients. This retrospective study was designed to identify the risk factors associated with POD of type A aortic dissection patients. MATERIAL AND METHODS Clinical data of 148 patients with type A aortic dissection in the Department of Critical Care Medicine was retrospectively analyzed. All these patients underwent Sun's procedure with anesthetic treatment. The confusion assessment method for intensive care unit (CAM-ICU) was adapted to evaluate the delirium status of these patients. They were divided into 2 groups: the delirium group and the control group. Univariate analysis and multivariate logistic regression were performed in succession to determine the independent risk factors for POD. RESULTS The average age of these patients was 54.41±11.676 years old. Among the 148 patients, POD was detected in 68 patients, with an incidence of 45.95%. According to univariate analysis, age, irritability, alcohol use, extracorporeal circulation duration (cardiopulmonary bypass, CPB time), antegrade selective cerebral perfusion (ASCP) time, lowest partial pressure of oxygen (lowest PO2), mechanical ventilation time, blood loss, low PO₂ and oxygenation index, hemoglobin (Hb), Intensive Care Unit (ICU) stay, and dihydroxyphenylalanine (DEX) were associated with higher odds of POD among type A aortic dissection patients. According to further analysis of multivariate logistic regression, ASCP time and irritability were confirmed as the independent factors for POD of type A aortic dissection patients. CONCLUSIONS We determined 2 independent risk factors for POD: ASCP time and irritability. Identifying and adjusting these risk factors are very important in reducing the incidence of POD among type A aortic dissection patients.

Delirium after primary percutaneous coronary intervention in aged individuals with acute ST-segment elevation myocardial infarction: A retrospective study

The present prospective study aimed to investigate the incidence and risk factors of delirium after primary percutaneous coronary intervention (PCI) in older adults with acute ST-segment elevation myocardial infarction (STEMI). A total of 111 patients (age, ≥65 years) with acute STEMI following primary PCI were included in the present study. Neurocognitive testing was performed using the Mini-mental State Examination on the first day of hospitalization. Post-operative delirium was assessed using the Confusion Assessment Method for the Intensive Care Unit within the first four post-operative days. A total of 32 patients (28.8%) developed delirium after primary PCI. The independent predictors of delirium were older age [odds ratio (OR)=1.192, 95% confidence interval (CI)=1.07-1.328, P=0.001], living alone (OR=4.827, 95% CI=1.315-17.725, P=0.018), history of alcohol abuse (OR=3.875, 95% CI=1.168-12.857, P=0.026), longer duration of primary PCI (OR=1.152, 95% CI=1.077-1.232, P<0.001) and post-operative pain (current pain; OR=7.663, 95% CI=1.432-41.02, P=0.017). Compared to the patients without delirium, the participants who developed delirium had longer hospital stays and a higher rate of re-admission within 30 days after discharge. The mortality within one year after discharge (one-year mortality) was similar between patients with and without delirium. In conclusion, older patients (age, ≥65 years) with acute STEMI are at a relatively high risk of delirium following primary PCI. Higher age (≥65 years), living alone, history of alcohol dependence, longer length of primary PCI (>50 min) and post-operative pain (current pain) were determined to be risk factors for delirium after primary PCI in the present cohort.

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.

The use of clonidine in elderly patients with delirium; pharmacokinetics and hemodynamic responses

Background

The Oslo Study of Clonidine in Elderly Patients with Delirium (LUCID) is an RCT investigating the effect of clonidine in medical patients > 65 years with delirium. To assess the dosage regimen and safety measures of this study protocol, we measured the plasma concentrations and hemodynamic effects of clonidine in the first 20 patients.

Methods

Patients were randomised to clonidine (n = 10) or placebo (n = 10). The treatment group was given a loading dose (75μg every 3rd hour up to a maximum of 4 doses) to reach steady state, and further 75μg twice daily until delirium free for 2 days, discharge or a maximum of 7 days. Blood pressure (BP) and heart rate (HR) were measured just before every dose. If the systolic BP was < 100 mmHg or HR < 50 beats per minute the next dose was omitted. Plasma concentrations of clonidine were measured 3 h after each drug intake on day 1, just before intake (day 2 and at steady state day 4–6) and 3 h after intake at steady state (C_max). Our estimated pre-specified plasma concentration target range was 0.3–0.7μg/L.

Results

3 h after the first dose of 75μg clonidine, plasma concentration levels rose to median 0.35 (range 0.24–0.40)μg/L. Median trough concentration (C₀) at day 2 was 0.70 (0.47–0.96)μg/L. At steady state, median C₀ was 0.47 (0.36–0.76)μg/L, rising to C_max 0.74 (0.56–0.95)μg/L 3 h post dose. A significant haemodynamic change from baseline was only found at a few time-points during the loading doses within the clonidine group. There was however extensive individual BP and HR variation in both the clonidine and placebo groups, and when comparing the change scores (delta values) between the clonidine and the placebo groups, there were no significant differences.

Conclusions

The plasma concentration of clonidine was at the higher end of the estimated therapeutic range. Hemodynamic changes during clonidine treatment were as expected, with trends towards lower blood pressure and heart rate in patients treated with clonidine, but with dose adjustments based on SBP this protocol appears safe.

Trial registration

ClinicalTrials.gov NCT01956604, 09.25.2013. EudraCT Number: 2013–000815-26, 03.18.2013. Enrolment of first participant: 04.24.2014.

Alpha-2 adrenergic agonists for the prevention of cardiac complications among adults undergoing surgery

BACKGROUND

The surgical stress response plays an important role on the pathogenesis of perioperative cardiac complications. Alpha-2 adrenergic agonists attenuate this response and may help prevent postoperative cardiac complications.

OBJECTIVES

To determine the efficacy and safety of α-2 adrenergic agonists for reducing mortality and cardiac complications in adults undergoing cardiac surgery and non-cardiac surgery.

SEARCH METHODS

We searched CENTRAL (2017, Issue 4), MEDLINE (1950 to April Week 4, 2017), Embase (1980 to May 2017), the Science Citation Index, clinical trial registries, and reference lists of included articles.

SELECTION CRITERIA

We included randomized controlled trials that compared α-2 adrenergic agonists (i.e. clonidine, dexmedetomidine or mivazerol) against placebo or non-α-2 adrenergic agonists. Included trials had to evaluate the efficacy and safety of α-2 adrenergic agonists for preventing perioperative mortality or cardiac complications (or both), or measure one or more relevant outcomes (i.e. death, myocardial infarction, heart failure, acute stroke, supraventricular tachyarrhythmia and myocardial ischaemia).

DATA COLLECTION AND ANALYSIS

Two authors independently assessed trial quality, extracted data and independently performed computer entry of abstracted data. We contacted study authors for additional information. Adverse event data were gathered from the trials. We evaluated included studies using the Cochrane 'Risk of bias' tool, and the quality of the evidence underlying pooled treatment effects using GRADE methodology. Given the clinical heterogeneity between cardiac and non-cardiac surgery, we analysed these subgroups separately. We expressed treatment effects as pooled risk ratios (RR) with 95% confidence intervals (CI).

MAIN RESULTS

We included 47 trials with 17,039 participants. Of these studies, 24 trials only included participants undergoing cardiac surgery, 23 only included participants undergoing non-cardiac surgery and eight only included participants undergoing vascular surgery. The α-2 adrenergic agonist studied was clonidine in 21 trials, dexmedetomidine in 24 trials and mivazerol in two trials.In non-cardiac surgery, there was high quality evidence that α-2 adrenergic agonists led to a similar risk of all-cause mortality compared with control groups (1.3% with α-2 adrenergic agonists versus 1.7% with control; RR 0.80, 95% CI 0.61 to 1.04; participants = 14,081; studies = 16). Additionally, the risk of cardiac mortality was similar between treatment groups (0.8% with α-2 adrenergic agonists versus 1.0% with control; RR 0.86, 95% CI 0.60 to 1.23; participants = 12,525; studies = 5, high quality evidence). The risk of myocardial infarction was probably similar between treatment groups (RR 0.94, 95% CI 0.69 to 1.27; participants = 13,907; studies = 12, moderate quality evidence). There was no associated effect on the risk of stroke (RR 0.93, 95% CI 0.55 to 1.56; participants = 11,542; studies = 7; high quality evidence). Conversely, α-2 adrenergic agonists probably increase the risks of clinically significant bradycardia (RR 1.59, 95% CI 1.18 to 2.13; participants = 14,035; studies = 16) and hypotension (RR 1.24, 95% CI 1.03 to 1.48; participants = 13,738; studies = 15), based on moderate quality evidence.There was insufficient evidence to determine the effect of α-2 adrenergic agonists on all-cause mortality in cardiac surgery (RR 0.52, 95% CI 0.26 to 1.04; participants = 1947; studies = 16) and myocardial infarction (RR 1.01, 95% CI 0.43 to 2.40; participants = 782; studies = 8), based on moderate quality evidence. There was one cardiac death in the clonidine arm of a study of 22 participants. Based on very limited data, α-2 adrenergic agonists may have reduced the risk of stroke (RR 0.37, 95% CI 0.15 to 0.93; participants = 1175; studies = 7; outcome events = 18; low quality evidence). Conversely, α-2 adrenergic agonists increased the risk of bradycardia from 6.4% to 12.0% (RR 1.88, 95% CI 1.35 to 2.62; participants = 1477; studies = 10; moderate quality evidence), but their effect on hypotension was uncertain (RR 1.19, 95% CI 0.87 to 1.64; participants = 1413; studies = 9; low quality evidence).These results were qualitatively unchanged in subgroup analyses and sensitivity analyses.

AUTHORS' CONCLUSIONS

Our review concludes that prophylactic α-2 adrenergic agonists generally do not prevent perioperative death or major cardiac complications. For non-cardiac surgery, there is moderate-to-high quality evidence that these agents do not prevent death, myocardial infarction or stroke. Conversely, there is moderate quality evidence that these agents have important adverse effects, namely increased risks of hypotension and bradycardia. For cardiac surgery, there is moderate quality evidence that α-2 adrenergic agonists have no effect on the risk of mortality or myocardial infarction, and that they increase the risk of bradycardia. The quality of evidence was inadequate to draw conclusions regarding the effects of alpha-2 agonists on stroke or hypotension during cardiac surgery.

Acute Brain Failure: Pathophysiology, Diagnosis, Management, and Sequelae of Delirium

Delirium is the most common psychiatric syndrome found in the general hospital setting, with an incidence as high as 87% in the acute care setting. Delirium is a neurobehavioral syndrome caused by the transient disruption of normal neuronal activity secondary to systemic disturbances. The development of delirium is associated with increased morbidity, mortality, cost of care, hospital-acquired complications, placement in specialized intermediate and long-term care facilities, slower rate of recovery, poor functional and cognitive recovery, decreased quality of life, and prolonged hospital stays. This article discusses the epidemiology, known etiological factors, presentation and characteristics, prevention, management, and impact of delirium.

The Sedative Effect of Propranolol on Critically Ill Patients: A Case Series

INTRODUCTION

Recent studies have examined the effectiveness of alpha-2 adrenergic agonists for controlling delirium and agitation. Propranolol, a non-selective beta-adrenergic antagonist with good penetration of the blood-brain barrier, has not been investigated for this purpose.

MATERIALS AND METHODS

We retrospectively reviewed the medical records of all patients who were prescribed propranolol in our Medical Surgical ICU from January 1, 2010, to December 31, 2013. We recorded the sedation level and daily dose of sedatives, analgesics, and antipsychotics administered each day for 6 days after starting propranolol, and compared them to the day before starting propranolol.

RESULTS

Sixty-four patients met inclusion criteria. Thirty-eight episodes met exclusion criteria, leaving 27 patients (31 episodes). The administration of propranolol was associated with significant reductions in fentanyl equivalents (65%, p = 0.009), midazolam equivalents (57%, p = 0.048), propofol (16%, p = 0.009), and haloperidol (44%, p = 0.024) on day 2 after starting propranolol compared with baseline. A stratified analysis showed that these decreases were seen regardless of clinical improvement or deterioration.

CONCLUSION

The use of propranolol was associated with a significant reduction in doses of sedatives and analgesia. Further studies are needed to determine whether propranolol may be a useful adjuvant for managing delirium and agitation in the ICU.

Sedation of mechanically ventilated adults in intensive care unit: a network meta-analysis

Sedatives are commonly used for mechanically ventilated patients in intensive care units (ICU). However, a variety of sedatives are available and their efficacy and safety have been compared in numerous trials with inconsistent results. To resolve uncertainties regarding usefulness of these sedatives, we performed a systematic review and network meta-analysis. Randomized controlled trials comparing sedatives in mechanically ventilated ICU patients were included. Graph-theoretical methods were employed for network meta-analysis. A total of 51 citations comprising 52 RCTs were included in our analysis. Dexmedetomidine showed shorter MV duration than lorazepam (mean difference (MD): 68.7; 95% CI: 18.2-119.3 hours), midazolam (MD: 10.2; 95% CI: 7.7-12.7 hours) and propofol (MD: 3.4; 95% CI: 0.9-5.9 hours). Compared with dexmedetomidine, midazolam was associated with significantly increased risk of delirium (OR: 2.47; 95% CI: 1.17-5.19). Our study shows that dexmedetomidine has potential benefits in reducing duration of MV and lowering the risk of delirium.

Clonidine for sedation in the critically ill: a systematic review and meta-analysis

Background

This systematic review and meta-analysis investigates the efficacy and safety of clonidine as a sedative in critically ill patients requiring invasive mechanical ventilation.

Methods

We performed a comprehensive search of MEDLINE, EMBASE, CINAHL and the Cochrane trial registry. We identified RCTs that compared clonidine to any non-clonidine regimen in critically ill patients, excluding neonates, requiring mechanical ventilation. The GRADE method was used to assess certainty of evidence.

Results

We included eight RCTs (n = 642 patients). In seven of the trials clonidine was used for adjunctive rather than stand-alone sedation. There was no difference in the duration of mechanical ventilation (mean difference (MD) 0.05 days, 95% confidence interval (CI) = -0.65 to 0.75, I² = 86%, moderate certainty), ICU mortality (relative risk (RR) 0.98, 95% CI = 0.51 to 1.90, I² = 0%, low certainty), or ICU length of stay (MD 0.04 days, 95% CI = -0.46 to 0.53, I² = 16%, moderate certainty), with clonidine. There was a significant reduction in the total dose of narcotics (standard mean difference (SMD) -0.26, 95% CI = -0.50 to -0.02, I² = 0%, moderate certainty) with clonidine use. Clonidine was associated with increased incidence of clinically significant hypotension (RR 3.11, 95% CI = 1.64 to 5.87, I² = 0%, moderate certainty).

Conclusions

Until further RCTs are performed, data remains insufficient to support the routine use of clonidine as a sedative in the mechanically ventilated population. Clonidine may act as a narcotic-sparing agent, albeit with an increased risk of clinically significant hypotension.

Delirium in the Intensive Care Unit

Delirium is characterized by impaired cognition with nonspecific manifestations. In critically ill patients, it may develop secondary to multiple precipitating or predisposing causes. Although it can be a transient and reversible syndrome, its occurrence in Intensive Care Unit (ICU) patients may be associated with long-term cognitive dysfunction. This condition is often under-recognized by treating physicians, leading to inappropriate management. For appropriate management of delirium, early identification and risk factor assessment are key factors. Multidisciplinary collaboration and standardized care can enhance the recognition of delirium. Interdisciplinary team working, together with updated guideline implementation, demonstrates proven success in minimizing delirium in the ICU. Moreover, should the use of physical restraint be necessary to prevent harm among mechanically ventilated patients, ethical clinical practice methodology must be employed. This traditional narrative review aims to address the presentation, risk factors, management, and ethical considerations in the management of delirium in ICU settings.

Preventive strategies and potential therapeutic interventions for delirium in sepsis

Delirium is the most frequent and severe clinical presentation of brain dysfunction in critically ill septic patients with an incidence ranging from 9% to 71%. Delirium represents a significant burden for patients and relatives, as well as to the health care system, resulting in higher costs, long-term cognitive impairment and significant risk of death after 6 months. Current interventions for the prevention of delirium typically involve early recognition and amelioration of modifiable risk factors and treatment of underlying conditions that predisposes the individual to delirium. Several pharmacological interventions to prevent and treat delirium have been tested, although their effectiveness remains uncertain, especially in larger and more homogeneous subgroups of ICU patients, like in patients with sepsis. To date, there is inconsistent and conflicting data regarding the efficacy of any particular pharmacological agent, thus substantial attention has been paid to non-pharmacological interventions and preventive strategies should be applied to every patient admitted in the ICU. Future trials should be designed to evaluate the impact of these pharmacologic interventions on the prevention and treatment of delirium on clinically relevant outcomes such as length of stay, hospital mortality and long-term cognitive function. The role of specific medications like statins in delirium prevention is also yet to be evaluated.

[Delirium Prevention]

INTRODUCTION

Delirium is the most prevalent neuropsychiatric syndrome in the general hospital. Its presence is a marker of poor prognosis for patients. Its prevention could be the most effective strategy for reducing its frequency and its complications.

OBJECTIVE

To review recent findings and strategies for the prevention of delirium.

METHODOLOGY

A non-systematic review of scientific articles published in the last ten years in Spanish and English. A search was made in databases such as MEDLINE, Cochrane, EMBASE, Ovid, and ScienceDirect, for articles that included the terms, delirium and prevention.

RESULTS

Identification of predisposing and precipitating factors for delirium and a better understanding of the pathophysiological mechanisms underlying the onset of delirium have enabled the implementation of various pharmacological and non-pharmacological strategies in patients at high risk to develop hospital delirium. The studies to prevent delirium have focused on surgical patients. The current evidence supports the daily implementation of non-pharmacological measures to prevent delirium, as they are easy and cost effective. The available evidence is still limited to recommend the daily use of pharmacological strategies in delirium prophylaxis, and there is a consensus against the modest use of antipsychotic drugs in surgical patients and dexmedetomidine in patients in intensive care.

CONCLUSIONS

New high-quality clinical trials and studies involving non-surgical patients are needed to provide more evidence about this subject.

Evaluating the transition from dexmedetomidine to clonidine for agitation management in the intensive care unit

OBJECTIVES

Limited literature exists examining the use of enteral clonidine to transition patients from dexmedetomidine for management of agitation. The aim of this study was to evaluate dexmedetomidine discontinuation within 8 h of enteral clonidine administration in addition to the rates of dexmedetomidine re-initiation in patients who failed clonidine transition.

METHODS

A single-center, retrospective analysis evaluated critically ill adult patients from 1 February 2013 to 28 February 2014, who used dexmedetomidine and clonidine for sedation management. Patients were excluded if they received enteral clonidine for reasons other than sedation management. Secondary aims of the study observed time to dexmedetomidine discontinuation, agitation (Richmond Agitation Sedation Scale) and delirium ratings (Confusion Assessment Method for the intensive care unit), clonidine dose, and enteral clonidine discontinuation.

RESULTS

In all, 26 patients were evaluated. Demographics included a mean age of 54.4 (±16.7) years, Acute Physiology and Chronic Health Evaluation II score of 18 (interquartile range = 14-22), and 80.7% of admissions to the cardiac surgery intensive care unit. Dexmedetomidine discontinuation occurred in 17 (65.4%) patients within 8 h of receiving clonidine. The total median clonidine exposure per intensive care unit day was 0.35 mg/ICU day (interquartile range = 0.2-0.5) in patients who discontinued dexmedetomidine within 8 h and 0.5 mg/ICU day (interquartile range = 0.4-1.0) (p = 0.036) in patients who did not. We observed similar Richmond Agitation Sedation Scale and Confusion Assessment Method for the intensive care unit scores and rates of hypotension. Unintentional use of clonidine beyond ICU and hospital stay was observed in 54% and 23% of patients, respectively.

CONCLUSION

Enteral clonidine may be an effective and safe alternative to transition patients off of dexmedetomidine for ongoing sedation management. Clinicians should critically evaluate the need for clonidine at ICU and hospital discharge. More studies comparing the use of clonidine to transition from dexmedetomidine infusions are needed.

Pharmacologic agents for the prevention and treatment of delirium in patients undergoing cardiac surgery: systematic review and metaanalysis

OBJECTIVES

Postcardiac surgery delirium is associated with increased risks of morbidity, cognitive decline, poor health-related quality of life and mortality, and higher healthcare costs. We performed a systematic review of randomized controlled trials to examine the effect of pharmacologic agents for the prevention and the treatment of delirium after cardiac surgery.

DATA SOURCES

Electronic search on PubMed, Medline, Embase, Cochrane Central Register of Controlled Trials, ISI Web of Science, and CINAHL up to December 2013.

STUDY SELECTION

Randomized controlled trials of pharmacologic agents used for the prevention and the treatment of delirium after emergency or elective cardiac surgery in adults.

DATA EXTRACTION

We extracted data on patient population, pharmacologic agents, delirium characteristics, rescue treatment, length of stays in the ICU and hospital, and mortality. For each trial, we assessed the risk of bias domains and rated the quality of evidence using the Grading of Recommendations Assessment, Development and Evaluation approach.

DATA SYNTHESIS

Of the 13 studies (10 prevention and three treatment) involving 5,848 patients, one multicentered randomized controlled trial on prophylactic dexamethasone made up 77% of the total sample size. The use of pharmacologic agents (dexamethasone, rivastigmine, risperidone, ketamine, dexmedetomidine, propofol, and clonidine) reduced the risk of delirium (relative risk, 0.57; 95% CI, 0.40-0.80) with quality of evidence rated as moderate. There was high quality of evidence for no increased risk of mortality (relative risk, 0.89; 95% CI, 0.57-1.38) associated with the use of prophylactic pharmacologic agents. Metaanalysis of treatment trials was not undertaken because of high heterogeneity. In two small trials (total number of patients = 133), haloperidol did not appear to be effective in treating delirium.

CONCLUSIONS

Moderate to high-quality evidence supports the use of pharmacologic agents for the prevention of delirium, but results are based largely on one randomized controlled trial. The evidence for treating postcardiac surgery delirium with pharmacologic agents is inconclusive.

Pharmacologic prevention and treatment of delirium in intensive care patients: A systematic review

PURPOSE

The purpose of the study is to determine if pharmacologic approaches are effective in prevention and treatment of delirium in critically ill patients.

MATERIALS AND METHODS

We performed a systematic search to identify publications (from January 1980 to September 2014) that evaluated the pharmacologic interventions to treat or prevent delirium in intensive care unit (ICU) patients.

RESULTS

From 2646 citations, 15 studies on prevention (6729 patients) and 7 studies on treatment (1784 patients) were selected and analyzed. Among studies that evaluated surgical patients, the pharmacologic interventions were associated with a reduction in delirium prevalence, ICU length of stay, and duration of mechanical ventilation, but with high heterogeneity (respectively, I(2) = 81%, P = .0013; I(2) = 97%, P < .001; and I(2) = 97%). Considering treatment studies, only 1 demonstrated a significant decrease in ICU length of stay using dexmedetomidine compared to haloperidol (Relative Risk, 0.62 [1.29-0.06]; I(2) = 97%), and only 1 found a shorter time to resolution of delirium using quetiapine (1.0 [confidence interval, 0.5-3.0] vs 4.5 [confidence interval, 2.0-7.0] days; P = .001).

CONCLUSION

The use of antipsychotics for surgical ICU patients and dexmedetomidine for mechanically ventilated patients as a preventive strategy may reduce the prevalence of delirium in the ICU. None of the studied agents that were used for delirium treatment improved major clinical outcome, including mortality.

The protocol of the Oslo Study of Clonidine in Elderly Patients with Delirium; LUCID: a randomised placebo-controlled trial

Background

Delirium affects 15% of hospitalised patients and is linked with poor outcomes, yet few pharmacological treatment options exist. One hypothesis is that delirium may in part result from exaggerated and/or prolonged stress responses. Dexmedetomidine, a parenterally-administered alpha2-adrenergic receptor agonist which attenuates sympathetic nervous system activity, shows promise as treatment in ICU delirium. Clonidine exhibits similar pharmacodynamic properties and can be administered orally. We therefore wish to explore possible effects of clonidine upon the duration and severity of delirium in general medical inpatients.

Methods/Design

The Oslo Study of Clonidine in Elderly Patients with Delirium (LUCID) is a randomised, placebo-controlled, double-blinded, parallel group study with 4-month prospective follow-up. We will recruit 100 older medical inpatients with delirium or subsyndromal delirium in the acute geriatric ward. Participants will be randomised to oral clonidine or placebo until delirium free for 2 days (Diagnostic and Statistical Manual of Mental Disorders (DSM-5) criteria), or after a maximum of 7 days treatment. Assessment of haemodynamics (blood pressure, heart rate and electrocardiogram) and delirium will be performed daily until discharge or a maximum of 7 days after end of treatment. The primary endpoint is the trajectory of delirium over time (measured by Memorial Delirium Assessment Scale). Secondary endpoints include the duration of delirium, use of rescue medication for delirium, pharmacokinetics and pharmacodynamics of clonidine, cognitive function after 4 months, length of hospital stay and need for institutionalisation.

Discussion

LUCID will explore the efficacy and safety of clonidine for delirium in older medical inpatients.

Trial registration

ClinicalTrials.gov NCT01956604. EudraCT Number: 2013-000815-26

Alpha-2 agonists for long-term sedation during mechanical ventilation in critically ill patients

BACKGROUND

Sedation reduces patient levels of anxiety and stress, facilitates the delivery of care and ensures safety. Alpha-2 agonists have a range of effects including sedation, analgesia and antianxiety. They sedate, but allow staff to interact with patients and do not suppress respiration. They are attractive alternatives for long-term sedation during mechanical ventilation in critically ill patients.

OBJECTIVES

To assess the safety and efficacy of alpha-2 agonists for sedation of more than 24 hours, compared with traditional sedatives, in mechanically-ventilated critically ill patients.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL, Issue 10, 2014), MEDLINE (1946 to 9 October 2014), EMBASE (1980 to 9 October 2014), CINAHL (1982 to 9 October 2014), Latin American and Caribbean Health Sciences Literature (1982 to 9 October 2014), ISI Web of Science (1987 to 9 October 2014), Chinese Biological Medical Database (1978 to 9 October 2014) and China National Knowledge Infrastructure (1979 to 9 October 2014), the World Health Organization international clinical trials registry platform (to 9 October 2014), Current Controlled Trials metaRegister of controlled trials active registers (to 9 October 2014), the ClinicalTrials.gov database (to 9 October 2014), the conference proceedings citation index (to 9 October 2014) and the reference lists of included studies and previously published meta-analyses and systematic reviews for relevant studies. We imposed no language restriction.

SELECTION CRITERIA

We included all randomized and quasi-randomized controlled trials comparing alpha-2 agonists (clonidine or dexmedetomidine) versus alternative sedatives for long-term sedation (more than 24 hours) during mechanical ventilation in critically ill patients.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed study quality and extracted data. We contacted study authors for additional information. We performed meta-analyses when more than three studies were included, and selected a random-effects model due to expected clinical heterogeneity. We calculated the geometric mean difference for continuous outcomes and the risk ratio for dichotomous outcomes. We described the effects by values and 95% confidence intervals (CIs). We considered two-sided P < 0.05 to be statistically significant.

MAIN RESULTS

Seven studies, covering 1624 participants, met the inclusion criteria. All included studies investigated adults and compared dexmedetomidine with traditional sedatives, including propofol, midazolam and lorazepam. Compared with traditional sedatives, dexmedetomidine reduced the geometric mean duration of mechanical ventilation by 22% (95% CI 10% to 33%; four studies, 1120 participants, low quality evidence), and consequently the length of stay in the intensive care unit (ICU) by 14% (95% CI 1% to 24%; five studies, 1223 participants, very low quality evidence). There was no evidence that dexmedetomidine decreased the risk of delirium (RR 0.85; 95% CI 0.63 to 1.14; seven studies, 1624 participants, very low quality evidence) as results were consistent with both no effect and appreciable benefit. Only one study assessed the risk of coma, but lacked methodological reliability (RR 0.69; 95% CI 0.55 to 0.86, very low quality evidence). Of all the adverse events included, the most commonly reported one was bradycardia, and we observed a doubled (111%) increase in the incidence of bradycardia (RR 2.11; 95% CI 1.39 to 3.20; six studies, 1587 participants, very low quality evidence). Our meta-analysis provided no evidence that dexmedetomidine had any impact on mortality (RR 0.99; 95% CI 0.79 to 1.24; six studies, 1584 participants, very low quality evidence). We observed high levels of heterogeneity in risk of delirium (I² = 70%), but due to the limited number of studies we were unable to determine the source of heterogeneity through subgroup analyses or meta-regression. We judged six of the seven studies to be at high risk of bias.

AUTHORS' CONCLUSIONS

In this review, we found no eligible studies for children or for clonidine. Compared with traditional sedatives, long-term sedation using dexmedetomidine in critically ill adults reduced the duration of mechanical ventilation and ICU length of stay. There was no evidence for a beneficial effect on risk of delirium and the heterogeneity was high. The evidence for risk of coma was inadequate. The most common adverse event was bradycardia. No evidence indicated that dexmedetomidine changed mortality. The general quality of evidence ranged from very low to low, due to high risks of bias, serious inconsistency and imprecision, and strongly suspected publication bias. Future studies could pay more attention to children and to using clonidine

Randomized ICU trials do not demonstrate an association between interventions that reduce delirium duration and short-term mortality: a systematic review and meta-analysis

OBJECTIVES

We reviewed randomized trials of adult ICU patients of interventions hypothesized to reduce delirium burden to determine whether interventions that are more effective at reducing delirium duration are associated with a reduction in short-term mortality.

DATA SOURCES

We searched CINHAHL, EMBASE, MEDLINE, and the Cochrane databases from 2001 to 2012.

STUDY SELECTION

Citations were screened for randomized trials that enrolled critically ill adults, evaluated delirium at least daily, compared a drug or nondrug intervention hypothesized to reduce delirium burden with standard care (or control), and reported delirium duration and/or short-term mortality (≤ 45 d).

DATA EXTRACTION

In duplicate, we abstracted trial characteristics and results and evaluated quality using the Cochrane risk of bias tool. We performed random effects model meta-analyses and meta-regressions.

DATA SYNTHESIS

We included 17 trials enrolling 2,849 patients which evaluated a pharmacologic intervention (n = 13) (dexmedetomidine [n = 6], an antipsychotic [n = 4], rivastigmine [n = 2], and clonidine [n = 1]), a multimodal intervention (n = 2) (spontaneous awakening [n = 2]), or a nonpharmacologic intervention (n = 2) (early mobilization [n = 1] and increased perfusion [n = 1]). Overall, average delirium duration was lower in the intervention groups (difference = -0.64 d; 95% CI, -1.15 to -0.13; p = 0.01) being reduced by more than or equal to 3 days in three studies, 0.1 to less than 3 days in six studies, 0 day in seven studies, and less than 0 day in one study. Across interventions, for 13 studies where short-term mortality was reported, short-term mortality was not reduced (risk ratio = 0.90; 95% CI, 0.76-1.06; p = 0.19). Across 13 studies that reported mortality, meta-regression revealed that delirium duration was not associated with reduced short-term mortality (p = 0.11).

CONCLUSIONS

A review of current evidence fails to support that ICU interventions that reduce delirium duration reduce short-term mortality. Larger controlled studies are needed to establish this relationship.

Antipsychotic prophylaxis in surgical patients modestly decreases delirium incidence--but not duration--in high-incidence samples: a meta-analysis

OBJECTIVE

The objective was to examine whether prophylactic treatment with antipsychotics can decrease the incidence and severity of postsurgical delirium.

METHOD

A meta-analysis of existing trials comparing delirium incidence between patients given prophylactic antipsychotic and placebo was performed. Secondary outcomes were total hospital days, total days of delirium and severity. Pooled odds ratios (ORs) and mean differences were calculated using a random-effects model.

RESULTS

Five randomized placebo-controlled trials comprising a total of 1491 patients were included. In the pooled analysis, prophylactic antipsychotic administration showed a reduction in delirium incidence (OR: 0.42; 95% confidence interval (CI): 0.24, 0.74). Among the studies reporting other outcomes, patients receiving antipsychotics prophylactically showed no differences in total hospital days (0.1; 95% CI: -0.73, 0.94), days of delirium (-1.17; 95% CI: -5.22, 2.88) or delirium severity (-1.02; 95% CI: -6.81, 4.76).

CONCLUSIONS

Prophylactic antipsychotic treatment in surgical patients modestly decreases the incidence of delirium, but not the length of hospital stay, duration of delirium or its severity. Given the modest protective effect of antipsychotics and their potential adverse reactions, there is insufficient evidence to support its universal use as a preventive agent, though potential benefit may be seen in populations at high risk of developing delirium.

Strategies for prevention of postoperative delirium: a systematic review and meta-analysis of randomized trials

INTRODUCTION

The ideal measures to prevent postoperative delirium remain unestablished. We conducted this systematic review and meta-analysis to clarify the significance of potential interventions.

METHODS

The PRISMA statement guidelines were followed. Two researchers searched MEDLINE, EMBASE, CINAHL and the Cochrane Library for articles published in English before August 2012. Additional sources included reference lists from reviews and related articles from 'Google Scholar'. Randomized clinical trials (RCTs) on interventions seeking to prevent postoperative delirium in adult patients were included. Data extraction and methodological quality assessment were performed using predefined data fields and scoring system. Meta-analysis was accomplished for studies that used similar strategies. The primary outcome measure was the incidence of postoperative delirium. We further tested whether interventions effective in preventing postoperative delirium shortened the length of hospital stay.

RESULTS

We identified 38 RCTs with interventions ranging from perioperative managements to pharmacological, psychological or multicomponent interventions. Meta-analysis showed dexmedetomidine sedation was associated with less delirium compared to sedation produced by other drugs (two RCTs with 415 patients, pooled risk ratio (RR)=0.39; 95% confidence interval (CI)=0.16 to 0.95). Both typical (three RCTs with 965 patients, RR=0.71; 95% CI=0.54 to 0.93) and atypical antipsychotics (three RCTs with 627 patients, RR=0.36; 95% CI=0.26 to 0.50) decreased delirium occurrence when compared to placebos. Multicomponent interventions (two RCTs with 325 patients, RR=0.71; 95% CI=0.58 to 0.86) were effective in preventing delirium. No difference in the incidences of delirium was found between: neuraxial and general anesthesia (four RCTs with 511 patients, RR=0.99; 95% CI=0.65 to 1.50); epidural and intravenous analgesia (three RCTs with 167 patients, RR=0.93; 95% CI=0.61 to 1.43) or acetylcholinesterase inhibitors and placebo (four RCTs with 242 patients, RR=0.95; 95% CI=0.63 to 1.44). Effective prevention of postoperative delirium did not shorten the length of hospital stay (10 RCTs with 1,636 patients, pooled SMD (standard mean difference)=-0.06; 95% CI=-0.16 to 0.04).

CONCLUSIONS

The included studies showed great inconsistencies in definition, incidence, severity and duration of postoperative delirium. Meta-analysis supported dexmedetomidine sedation, multicomponent interventions and antipsychotics were useful in preventing postoperative delirium.

[Dexmedetomidine and clonidine: a review of their pharmacodynamy to define their role for sedation in intensive care patients]

Alpha-2 adrenergic agonists ("alpha-2 agonists") present multiple pharmacodynamic effects: rousable sedation, decreased incidence of delirium in the setting of critical care, preservation of respiratory drive, decreased whole body oxygen consumption, decreased systemic and pulmonary arterial impedance, improved left ventricular systolic and diastolic function, preserved vascular reactivity to exogenous catecholamines, preserved vasomotor baroreflex with lowered set point, preserved kidney function, decreased protein catabolism. These pharmacodynamic effects explain the interest for these drugs in the critical care setting. However, their exact role for sedation in critically ill-patients remains open for further studies. Given the few double-blind randomized multicentric trials available, the present non exhaustive analysis of the literature aims at presenting the utilization of alpha-2 agonists as potential first-line sedative agents, in the critical care setting. Suggestions regarding the use of alpha-2 agonists as sedatives are detailed.

A review of pharmacologic management and prevention strategies for delirium in the intensive care unit

BACKGROUND

The prevalence of delirium has been estimated at anywhere between 10% and 30% in general medical patients and in upwards of 80% in patients who are admitted to an intensive care unit (ICU). Given the high prevalence of delirium in the ICU population, it should not be surprising that a large percentage of psychiatric consults arise from this setting. While the mainstay of pharmacologic management of delirium centers on neuroleptic medications, such as haloperidol, recent studies using alternate agents have shown varying levels of promise.

OBJECTIVE

Our purpose is to outline the major prospective studies looking at the efficacy of pharmacologic management and prevention strategies for delirium exclusively in adult ICU patients. Both conventional and novel pharmacotherapeutic interventions are discussed.

METHOD

Articles were obtained using the MEDLINE/PUBMED database looking specifically at pharmacologic interventions for delirium in the intensive care unit. A search was performed using the key words"delirium," "intensive care unit," "treatment," and "prophylaxis." The authors limited their search to prospective studies, specifically randomized trials (both placebo-controlled and non-controlled) in the adult ICU population, and eliminated retrospective and observational studies. Relevant citations from the previously mentioned articles were also included in the review.

CONCLUSION

There is a plethora of studies on pharmacologic management strategies in general medical patients with delirium. Findings from these studies are often extrapolated to the ICU population; however, when looking at studies limited to ICU patients with delirium, there are far fewer credible prospective studies.