Glucocorticoid-endocannabinoid interaction in cardiac surgical patients: relationship to early cognitive dysfunction and late depression

Characteristics associated with effectiveness in postoperative delirium research: a systematic review of randomised controlled trials with meta-regression and meta-analysis

BACKGROUND

Postoperative delirium remains prevalent despite extensive research through randomised trials aimed at reducing its incidence. Understanding trial characteristics associated with interventions' effectiveness facilitates data interpretation.

METHODS

Trial characteristics were extracted from eligible trials identified through two systematic literature searches. Multivariable meta-regression was used to investigate trial characteristics associated with effectiveness estimated using odds ratios. Meta-analysis was used to investigate pooled effectiveness.

RESULTS

We identified 201 eligible trials. Compared with China, trials from the USA/Canada (ratio of odds ratio, 1.89; 95% confidence interval, 1.45-2.45) and Europe/Australia/New Zealand (1.67; 1.29-2.18) had an 89% and 67% higher odds ratio, respectively, suggesting reduced effectiveness. The effectiveness was enhanced when the incidence of postoperative delirium increased (0.85; 0.79-0.92, per 10% increase). Trials with concerns related to deviations from intended interventions reported increased effectiveness compared with those at low risk (0.69; 0.53-0.90). Compared with usual care, certain interventions appeared to have reduced the incidence of postoperative delirium in low-risk trials with low-to-moderate certainty of evidence. However, these findings should be considered inconclusive because of challenges in grouping heterogeneous interventions, the limited number of eligible trials, the prevalence of small-scale studies, and potential publication bias.

CONCLUSIONS

The effectiveness of postoperative delirium trials varied based on the region of trial origin, the incidence of delirium, and the risk of bias. The limitations caution against drawing definitive conclusions from different bodies of evidence. These findings highlight the imperative need to improve the quality of research on a global scale.

SYSTEMATIC REVIEW PROTOCOL

PROSPERO (CRD42023413984).

Effect of prophylactic corticosteroids on postoperative neurocognitive dysfunction in the adult population: An updated systematic review, meta-analysis, and trial sequential analysis of randomised controlled trials

Background and Aims

Postoperative neurocognitive dysfunction (PNCD) commonly occurs after surgery and prolongs hospital stays. Both direct noxious stimuli to the central nervous system and systemic inflammation have been implicated. Due to their potent anti-inflammatory effects, corticosteroids have been utilised to attenuate the incidence and severity of PNCD. This systematic review and meta-analysis strived to evaluate the prophylactic role of perioperative corticosteroids for PNCD.

Methods

A search was run in pre-defined databases for randomised controlled trials (RCTs) assessing the role of corticosteroids in preventing PNCD. The incidence of PNCD within 1 month was the primary outcome. Secondary outcomes included the use of antipsychotic medications for the treatment, postoperative infection, and hospital length of stay. The results are exhibited as odds ratio (OR) and the mean difference (MD) with 95% confidence interval (CI).

Results

Fifteen RCTs comprising 15,398 patients were included. The incidence of PNCD was significantly lower in the corticosteroid group than in the control group, with a pooled OR of 0.75 (95% CI 0.58, 0.96; P = 0.02; I2 = 66%). Trial sequential analysis showed the clinical benefit of corticosteroids in preventing PNCD; however, the requisite information size is still inadequate. The sub-group analysis supported the prophylactic effect of corticosteroids on delirium prevention but not on delayed neurocognitive recovery.

Conclusions

Our meta-analysis revealed statistically significant protective effects of corticosteroids on the incidence of PNCD. However, further studies are still needed to confirm the protective role of this commonly used and relatively safe strategy for preventing PNCD.

Prophylactic corticosteroids for cardiopulmonary bypass in adult cardiac surgery

BACKGROUND

Cardiac surgery triggers a strong inflammatory reaction, which carries significant clinical consequences. Corticosteroids have been suggested as a potential perioperative strategy to reduce inflammation and help prevent postoperative complications. However, the safety and effectiveness of perioperative corticosteroid use in adult cardiac surgery is uncertain. This is an update of the 2011 review with 18 studies added.

OBJECTIVES

Primary objective: to estimate the effects of prophylactic corticosteroid use in adults undergoing cardiac surgery with cardiopulmonary bypass on the: - co-primary endpoints of mortality, myocardial complications, and pulmonary complications; and - secondary outcomes including atrial fibrillation, infection, organ injury, known complications of steroid therapy, prolonged mechanical ventilation, prolonged postoperative stay, and cost-effectiveness.

SECONDARY OBJECTIVE

to explore the role of characteristics of the study cohort and specific features of the intervention in determining the treatment effects via a series of prespecified subgroup analyses.

SEARCH METHODS

We used standard, extensive Cochrane search methods to identify randomised studies assessing the effect of corticosteroids in adult cardiac surgery. The latest searches were performed on 14 October 2022.

SELECTION CRITERIA

We included randomised controlled trials in adults (over 18 years, either with a diagnosis of coronary artery disease or cardiac valve disease, or who were candidates for cardiac surgery with the use of cardiopulmonary bypass), comparing corticosteroids with no treatments. There were no restrictions with respect to length of the follow-up period. All selected studies qualified for pooling of results for one or more endpoints.

DATA COLLECTION AND ANALYSIS

We used standard Cochrane methods. Our primary outcomes were all-cause mortality, and cardiac and pulmonary complications. Secondary outcomes were infectious complications, gastrointestinal bleeding, occurrence of new post-surgery atrial fibrillation, re-thoracotomy for bleeding, neurological complications, renal failure, inotropic support, postoperative bleeding, mechanical ventilation time, length of stays in the intensive care unit (ICU) and hospital, patient quality of life, and cost-effectiveness. We used GRADE to assess the certainty of evidence for each outcome.

MAIN RESULTS

This updated review includes 72 randomised trials with 17,282 participants (all 72 trials with 16,962 participants were included in data synthesis). Four trials (6%) were considered at low risk of bias in all the domains. The median age of participants included in the studies was 62.9 years. Study populations consisted mainly (89%) of low-risk, first-time coronary artery bypass grafting (CABG) or valve surgery. The use of perioperative corticosteroids may result in little to no difference in all-cause mortality (risk with corticosteroids: 25 to 36 per 1000 versus 33 per 1000 with placebo or no treatment; risk ratio (RR) 0.90, 95% confidence interval (CI) 0.75 to 1.07; 25 studies, 14,940 participants; low-certainty evidence). Corticosteroids may increase the risk of myocardial complications (68 to 86 per 1000) compared with placebo or no treatment (66 per 1000; RR 1.16, 95% CI 1.04 to 1.31; 25 studies, 14,766 participants; low-certainty evidence), and may reduce the risk of pulmonary complications (risk with corticosteroids: 61 to 77 per 1000 versus 78 per 1000 with placebo/no treatment; RR 0.88, 0.78 to 0.99; 18 studies, 13,549 participants; low-certainty evidence). Analyses of secondary endpoints showed that corticosteroids may reduce the incidence of infectious complications (risk with corticosteroids: 94 to 113 per 1000 versus 123 per 1000 with placebo/no treatment; RR 0.84, 95% CI 0.76 to 0.92; 28 studies, 14,771 participants; low-certainty evidence). Corticosteroids may result in little to no difference in incidence of gastrointestinal bleeding (risk with corticosteroids: 9 to 17 per 1000 versus 10 per 1000 with placebo/no treatment; RR 1.21, 95% CI 0.87 to 1.67; 6 studies, 12,533 participants; low-certainty evidence) and renal failure (risk with corticosteroids: 23 to 35 per 1000 versus 34 per 1000 with placebo/no treatment; RR 0.84, 95% CI 0.69 to 1.02; 13 studies, 12,799; low-certainty evidence). Corticosteroids may reduce the length of hospital stay, but the evidence is very uncertain (-0.5 days, 0.97 to 0.04 fewer days of length of hospital stay compared with placebo/no treatment; 25 studies, 1841 participants; very low-certainty evidence). The results from the two largest trials included in the review possibly skew the overall findings from the meta-analysis.

AUTHORS' CONCLUSIONS

A systematic review of trials evaluating the organ protective effects of corticosteroids in cardiac surgery demonstrated little or no treatment effect on mortality, gastrointestinal bleeding, and renal failure. There were opposing treatment effects on cardiac and pulmonary complications, with evidence that corticosteroids may increase cardiac complications but reduce pulmonary complications; however, the level of certainty for these estimates was low. There were minor benefits from corticosteroid therapy for infectious complications, but the evidence on hospital length of stay was very uncertain. The inconsistent treatment effects across different outcomes and the limited data on high-risk groups reduced the applicability of the findings. Further research should explore the role of these drugs in specific, vulnerable cohorts.

Effects of Glucocorticoids on Postoperative Neurocognitive Disorders in Adult Patients: A Systematic Review and Meta-Analysis

Background

Postoperative neurocognitive disorders (PNDs) is common among surgical patients, however, the effect of glucocorticoids for preventing PNDs is not clear. This review aims to evaluate the effect of glucocorticoids on the incidence of PNDs in adult patients undergoing surgery.

Methods

The databases of PubMed/Medline, Embase, the Cochrane Library, and Web of science were searched for all available randomized controlled trials (RCTs) from inception to April 30, 2022. RCTs comparing the effect of glucocorticoids with placebo on the incidence of PNDs in adult surgical patients (≥18 years old) were eligible. Subgroup analyses and meta-regressions were performed to evaluate sources of clinical heterogeneity. The level of certainty for main outcomes were assessed by the Grading of Recommendations Assessment, Development and Evaluation (GRADE) methodology.

Results

Eleven trials with a total of 10,703 patients were identified. Compared with the control group, glucocorticoids did not reduce the incidence of PNDs (RR: 0.84, 95% CI: 0.67 to 1.06, P = 0.13, GRADE = moderate). Secondary analyses for primary outcome did not change the result. In addition, the length of ICU stay was decreased in glucocorticoids group (RR: −13.58, 95% CI: −26.37 to −0.80, P = 0.04, GRADE = low). However, there were no significant differences between groups with regards to the incidence of postoperative infection (RR: 0.94, 95% CI: 0.84 to 1.06, P = 0.30, GRADE = moderate), blood glucose level (RR: 1.05, 95% CI: −0.09 to 2.19, P = 0.07, GRADE = low), duration of mechanical ventilation (RR: −2.44, 95% CI: −5.47 to 0.59, P = 0.14, GRADE = low), length of hospital stay (RR: −0.09, 95% CI: −0.27 to 0.09, P = 0.33, GRADE = moderate) and 30-day mortality (RR: 0.86, 95% CI: 0.70 to 1.06, P = 0.16, GRADE = moderate).

Conclusions

This meta-analysis suggests that perioperative administration of glucocorticoids may not reduce the incidence of PNDs after surgery. The effect of glucocorticoids on decreased length of ICU stay needs further researches. Future high-quality trials using acknowledged criteria and validated diagnostic tools are needed to determine the influence of glucocorticoids on long-term PNDs.

Systematic Review Registration

https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42022302262, identifier: CRD42022302262.

SARS-CoV-2 Psychiatric Sequelae: A Review of Neuroendocrine Mechanisms and Therapeutic Strategies

From the earliest days of the coronavirus disease 2019 (COVID-19) pandemic, there have been reports of significant neurological and psychological symptoms following Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) infection. This narrative review is designed to examine the potential psychoneuroendocrine pathogenic mechanisms by which SARS-CoV-2 elicits psychiatric sequelae as well as to posit potential pharmacologic strategies to address and reverse these pathologies. Following a brief overview of neurological and psychological sequelae from previous viral pandemics, we address mechanisms by which SARS-CoV-2 could enter or otherwise elicit changes in the CNS. We then examine the hypothesis that COVID-19-induced psychiatric disorders result from challenges to the neuroendocrine system, in particular the hypothalamic-pituitary-adrenal stress axis and monoamine synthesis, physiological mechanisms that are only further enhanced by the pandemic-induced social environment of fear, isolation, and socioeconomic pressure. Finally, we evaluate several FDA-approved therapeutics in the context of COVID-19-induced psychoneuroendocrine disorders.

Effects of Glucocorticoids on Postoperative Delirium in Adult Patients Undergoing Cardiac Surgery: A Systematic Review and Meta-analysis

PURPOSE

Delirium is a common neurologic complication after cardiac surgery and is associated with a poor prognosis. Several studies have explored the effects of glucocorticoids on postoperative delirium (POD). However, conclusion have been inconsistent. The purpose of this systematic review and meta-analysis is to evaluate the effects of glucocorticoids on POD in adult patients undergoing cardiac surgery.

METHODS

A systematic literature search was conducted using PubMed/MEDLINE, Embase, Cochrane Library/Central, and Web of Science from inception to January 28, 2021. Randomized controlled trials evaluating the effects of perioperative glucocorticoids administration on the incidence of POD in adults (≥18 years of age) undergoing cardiac surgery were included. The primary outcome of incidence of POD was assessed using the risk ratio (RR) with a fixed-effects model. Secondary analyses included the severity or duration of delirium, mortality at 30 days, length of hospital and intensive care unit (ICU) stay, duration of mechanical ventilatory support, the incidence of myocardial injury, new atrial fibrillation, renal and respiratory failure, postoperative infection and stroke, and the level of glucose and inflammatory factors.

FINDINGS

A total 4 trials (n = 8448 patients) were included. Glucocorticoids did not significantly reduce the incidence of POD (RR = 0.99; 95% CI, 0.86-1.14) but increased the risk of myocardial injury (RR = 1.22; 95% CI, 1.08-1.38), decreased the duration of mechanical ventilatory support (mean difference, -0.83; 95% CI, -1.32 to -0.34), and led to a tendency toward short length of ICU stay (mean difference, -0.22; 95% CI, -0.47 to -0.03). No significant differences were observed in other secondary outcomes.

IMPLICATIONS

The perioperative administration of glucocorticoids did not reduce the incidence of POD in adult patients undergoing cardiac surgery but might be associated with shorter duration of mechanical ventilatory support and a tendency toward a shorter length of ICU stay. Furthermore, we found that glucocorticoids may increase the rate of myocardial injury but have no effects on other clinical outcomes. International Prospective Register of Systematic Reviews identifier: CRD42021233458.

Circulating endocannabinoids and prospective risk for depression in trauma-injury survivors

Biological mechanisms associated with response to trauma may impact risk for depression. One such mechanism is endocannabinoid signaling (eCB), a neuromodulatory system comprised of the CB1 subtype of cannabinoid receptors (CB1R), encoded by the CNR1 gene, and two primary endogenous ligands: 2-arachidonoylglycerol (2-AG) and N-arachidonylethanolamine (AEA), hydrolyzed by monoacylglycerol lipase (gene name MGLL) and fatty acid amide hydrolase (gene name FAAH). Preclinical data suggest that eCB/CB1R signaling acts as a stress buffer and its loss or suppression increases depression-like behaviors. We examined circulating concentrations of the eCBs (2-AG and AEA) days and six months after a traumatic injury as a marker of eCB/CB1R signaling and as predictors of Center for Epidemiologic Studies of Depression Scale-Revised [CESD-R] scores as a measure of depression severity six months after injury. We also explored associations of CNR1, FAAH, and MGLL genetic variance with depression severity at six months. Results from hierarchical multiple linear regressions showed that higher 2-AG serum concentrations after trauma predicted greater depression at six months (β = 0.23, p = 0.007); neither AEA after trauma, nor 2-AG and AEA at six months were significant predictors (p's > 0.305). Carriers of minor allele for the putative single nucleotide polymorphism in the CNR1 gene rs806371 (β = 0.19, p = 0.024) experienced greater depression at six months. These data suggest that the eCB signaling system is highly activated following trauma and that eCB/CB1R activity contributes to long-term depression risk.

Glucocorticoids and the Brain after Critical Illness

Treatment for critical illness typically focuses on a patient's short-term physical recovery; however, recent work has broadened our understanding of the long-term implications of illness and treatment strategies. In particular, survivors of critical illness have significantly elevated risk of developing lasting cognitive impairment and psychiatric disorders. In this review, we examine the role of endogenous and exogenous glucocorticoids in neuropsychiatric outcomes following critical illness. Illness is marked by acute elevation of free cortisol and adrenocorticotropic hormone suppression, which typically normalize after recovery; however, prolonged dysregulation can sometimes occur. High glucocorticoid levels can cause lasting alterations to the plasticity and structural integrity of the hippocampus and prefrontal cortex, and this mechanism may plausibly contribute to impaired memory and cognition in critical illness survivors, though specific evidence is lacking. Glucocorticoids may also exacerbate inflammation-associated neural damage. Conversely, current evidence indicates that glucocorticoids during illness may protect against the development of post-traumatic stress disorder. We propose future directions for research in this field, including determining the role of persistent glucocorticoid elevations after illness in neuropsychiatric outcomes, the role of systemic vs neuroinflammation, and probing unexplored lines of investigation on the role of mineralocorticoid receptors and the gut-brain axis. Progress toward personalized medicine in this area has the potential to produce tangible improvements to the lives patients after a critical illness, including Coronavirus Disease 2019.

Effects of the Enhanced Recovery Program on the Recovery and Stress Response in Patients With Cancer Undergoing Pancreatoduodenectomy

Aim the study was the comparison of enhanced recovery after surgery (ERAS) versus conventional care (CON) protocols in patients undergoing pancreatoduodenectomy with regard to pain intensity, emotional response (optimism/sadness/stress), and stress biomarker levels (adrenocorticotropopic hormone, cortisol). We conducted a prospective two-group randomized controlled study with repeated measures in 85 patients with cancer pancreatoduodenectomy. In the ERAS group (N = 44), the ERAS protocol was followed, compared with the CON group (N = 41). We assessed pain with the numeric rating scale and a behavioral scale (Critical Care Pain Observation Tool), emotional responses (numeric rating scale), and serum adrenocorticotropopic hormone and cortisol levels at three time points: T1, admission day; T2, day of surgery; and T3, discharge day (ERAS) or the fifth day of stay (CON). Data were analyzed by linear mixed modeling to account for repeated measurements. We observed decreased postoperative pain in ERAS patients after adjusting for confounders (p = .002) and a trend for less complications. No significant associations with stress/emotional responses were noted. Only age, but not protocol, appeared to have a significant effect on adrenocorticotropopic hormone levels despite a significant interaction with time toward increased adrenocorticotropopic hormone levels in the ERAS group. In conclusion, despite its fast track nature, ERAS is not associated with increased stress in patients undergoing pancreatoduodenectomy and is associated with decreased pain.

Differential effect of interferon-alpha treatment on AEA and 2-AG levels

The endocannabinoid (eCB) system is one of the key players in immunoregulation, and reduced activity of the eCB system has been linked with depressive-like behaviours in animal studies and depression in clinical samples. There is a well-established link between immune activation and depression, such as following the administration of the pro-inflammatory cytokine, interferon-α (IFN-α), used to treat hepatitis C viral (HCV) infection. However, the role of peripheral endocannabinoids (eCBs), anandamide (AEA) and 2-arachidonoylglycerol (2-AG), following immunotherapy with IFN-α and in IFN-α -induced depression, have not been examined yet. In this study, we investigated whether circulating AEA and 2-AG were modified by treatment with IFN-α and whether they were involved in the development of IFN-α-induced depression. We also explored whether circulating eCBs were associated with peripheral cytokines during and after IFN-α treatment. We measured serum concentrations of AEA and 2-AG using High Performance Liquid Chromatography with Tandem Mass Spectrometry, and serum concentrations of cytokines using Meso Scale Discovery electrochemiluminescence V-PLEX assay, in 70 patients with HCV infection and 41 healthy subjects. We assessed HCV patients at baseline, IFN-α-treatment weeks (TW) 4 and 24, end of treatment (END) and at six months follow-up (FU). We assessed depression using M.I.N.I. International Neuropsychiatric Interview. We found a different pattern of change in peripheral AEA and 2-AG during and after IFN-α treatment. Whilst 2-AG increased earlier in immunotherapy (TW4), remained elevated throughout treatment, and reduced at six months follow-up (FU), AEA increased later in treatment (TW24) and remained elevated six months post-treatment. We also found that baseline levels of AEA were lower in HCV patients compared with healthy controls, whereas there were no differences in 2-AG levels. Interestingly, AEA, but not 2-AG, was significantly, negatively correlated with interleukin (IL)-2 and IL-17a at six months follow-up. We did not find any difference in both eCBs between patients with and without IFN-α-induced depression, at any time point. Our findings suggest that AEA and 2-AG are involved in different stages of immunoregulation following IFN-α treatment, where AEA might be involved in chronic inflammation. Lack of association between peripheral eCBs and IFN-α-induced depression suggests that different biological mechanisms may underpin inflammation-induced depression compared with classic "psychiatric" depression, or that any changes in the eCB system in depression may not be captured by peripheral AEA and 2-AG.

Prophylactic corticosteroids for paediatric heart surgery with cardiopulmonary bypass

BACKGROUND

Corticosteroids are routinely given to children undergoing cardiac surgery with cardiopulmonary bypass (CPB) in an attempt to ameliorate the inflammatory response. Their use is still controversial and the decision to administer the intervention can vary by centre and/or by individual doctors within that centre.

OBJECTIVES

This review is designed to assess the benefits and harms of prophylactic corticosteroids in children between birth and 18 years of age undergoing cardiac surgery with CPB.

SEARCH METHODS

We searched CENTRAL, MEDLINE, Embase and Conference Proceedings Citation Index-Science in June 2020. We also searched four clinical trials registers and conducted backward and forward citation searching of relevant articles.

SELECTION CRITERIA

We included studies of prophylactic administration of corticosteroids, including single and multiple doses, and all types of corticosteroids administered via any route and at any time-point in the perioperative period. We excluded studies if steroids were administered therapeutically. We included individually randomised controlled trials (RCTs), with two or more groups (e.g. multi-drug or dose comparisons with a control group) but not 'head-to-head' trials without a placebo or a group that did not receive corticosteroids. We included studies in children, from birth up to 18 years of age, including preterm infants, undergoing cardiac surgery with the use of CPB. We also excluded studies in patients undergoing heart or lung transplantation, or both; studies in patients already receiving corticosteroids; in patients with abnormalities of the hypothalamic-pituitary-adrenal axis; and in patients given steroids at the time of cardiac surgery for indications other than cardiac surgery.

DATA COLLECTION AND ANALYSIS

We used the Covidence systematic review manager to extract and manage data for the review. Two review authors independently assessed studies for inclusion, extracted data, and assessed risks of bias. We resolved disagreements by consensus or by consultation with a third review author. We assessed the certainty of evidence with GRADE.

MAIN RESULTS

We found 3748 studies, of which 888 were duplicate records. Two studies had the same clinical trial registration number, but reported different populations and interventions. We therefore included them as separate studies. We screened titles and abstracts of 2868 records and reviewed full text reports for 84 studies to determine eligibility. We extracted data for 13 studies. Pooled analyses are based on eight studies. We reported the remaining five studies narratively due to zero events for both intervention and placebo in the outcomes of interest. Therefore, the final meta-analysis included eight studies with a combined population of 478 participants. There was a low or unclear risk of bias across the domains. There was moderate certainty of evidence that corticosteroids do not change the risk of in-hospital mortality (five RCTs; 313 participants; risk ratio (RR) 0.83, 95% confidence interval (CI) 0.33 to 2.07) for children undergoing cardiac surgery with CPB. There was high certainty of evidence that corticosteroids reduce the duration of mechanical ventilation (six RCTs; 421 participants; mean difference (MD) 11.37 hours lower, 95% CI -20.29 to -2.45) after the surgery. There was high-certainty evidence that the intervention probably made little to no difference to the length of postoperative intensive care unit (ICU) stay (six RCTs; 421 participants; MD 0.28 days lower, 95% CI -0.79 to 0.24) and moderate-certainty evidence that the intervention probably made little to no difference to the length of the postoperative hospital stay (one RCT; 176 participants; mean length of stay 22 days; MD -0.70 days, 95% CI -2.62 to 1.22). There was moderate certainty of evidence for no effect of the intervention on all-cause mortality at the longest follow-up (five RCTs; 313 participants; RR 0.83, 95% CI 0.33 to 2.07) or cardiovascular mortality at the longest follow-up (three RCTs; 109 participants; RR 0.40, 95% CI 0.07 to 2.46). There was low certainty of evidence that corticosteroids probably make little to no difference to children separating from CPB (one RCT; 40 participants; RR 0.20, 95% CI 0.01 to 3.92). We were unable to report information regarding adverse events of the intervention due to the heterogeneity of reporting of outcomes. We downgraded the certainty of evidence for several reasons, including imprecision due to small sample sizes, a single study providing data for an individual outcome, the inclusion of both appreciable benefit and harm in the confidence interval, and publication bias.

AUTHORS' CONCLUSIONS

Corticosteroids  probably do not change the risk of mortality for children having heart surgery using CPB at any time point. They probably reduce the duration of postoperative ventilation in this context, but have little or no effect on the total length of postoperative ICU stay or total postoperative hospital stay. There was inconsistency in the adverse event outcomes reported which, consequently, could not be pooled. It is therefore impossible to provide any implications and policy-makers will be unable to make any recommendations for practice without evidence about adverse effects. The review highlighted the need for well-conducted RCTs powered for clinical outcomes to confirm or refute the effect of corticosteroids versus placebo in children having cardiac surgery with CPB. A core outcome set for adverse event reporting in the paediatric major surgery and intensive care setting is required.

2-Arachidonoylglycerol Modulation of Anxiety and Stress Adaptation: From Grass Roots to Novel Therapeutics

Over the past decade there has been a surge of interest in the development of endocannabinoid-based therapeutic approaches for the treatment of diverse neuropsychiatric conditions. Although initial preclinical and clinical development efforts focused on pharmacological inhibition of fatty acid amide hydrolase to elevate levels of the endocannabinoid anandamide, more recent efforts have focused on inhibition of monoacylglycerol lipase (MAGL) to enhance signaling of the most abundant and efficacious endocannabinoid ligand, 2-arachidonoylglycerol (2-AG). We review the biochemistry and physiology of 2-AG signaling and preclinical evidence supporting a role for this system in the regulation of anxiety-related outcomes and stress adaptation. We review preclinical evidence supporting MAGL inhibition for the treatment of affective, trauma-related, and stress-related disorders; describe the current state of MAGL inhibitor drug development; and discuss biological factors that could affect MAGL inhibitor efficacy. Issues related to the clinical advancement of MAGL inhibitors are also discussed. We are cautiously optimistic, as the field of MAGL inhibitor development transitions from preclinical to clinical and theoretical to practical, that pharmacological 2-AG augmentation could represent a mechanistically novel therapeutic approach for the treatment of affective and stress-related neuropsychiatric disorders.

No Impact of Preadmission Anti-Inflammatory Drug Use on Risk of Depression and Anxiety After Critical Illness

OBJECTIVES

Risk of depression and anxiety is elevated after intensive care. Drugs with anti-inflammatory properties may have antidepressant and anxiolytic effects. The aim of this study was to investigate the association between preadmission use of drugs with anti-inflammatory effects and risk of new-onset depression and anxiety among adult patients admitted to an ICU.

DESIGN

Propensity score-matched, population-based cohort study.

SETTING

All ICUs in Denmark from 2005 to 2013.

PATIENTS

Adults receiving mechanical ventilation in an ICU.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

A total of 48,207 ICU patients were included. Exposures were preadmission single-agent or combined use of statins, nonsteroidal anti-inflammatory drugs, or glucocorticoids. Outcomes were cumulative incidence (risk) and risk ratio of new-onset psychiatrist-diagnosed depression or anxiety or prescriptions for antidepressants or anxiolytics. Propensity score matching yielded 6,088 statin user pairs, 2,886 nonsteroidal anti-inflammatory drug user pairs, 1,440 glucocorticoid user pairs, and 1,743 combination drug user pairs. The cumulative incidence of anxiety and depression during the 3 years following intensive care was 18.0% (95% CI, 17.0-19.0%) for statin users, 21.3% (95% CI, 19.8-22.9%) for nonsteroidal anti-inflammatory drug users, 17.4% (95% CI, 15.4-19.5%) for glucocorticoid users, and 19.0% (95% CI, 16.3-20.2%) for combination users. The cumulative incidence was similar in nonusers compared with users in all drug groups. The risk ratio of depression and anxiety 3 years after admission to ICU was 1.04 (95% CI, 0.96-1.13) for statin users, 1.00 (95% CI, 0.90-1.11) for nonsteroidal anti-inflammatory drug users, 0.97 (95% CI, 0.82-1.14) for glucocorticoid users, and 1.05 (95% CI, 0.90-1.21) for combination users, compared with nonusers. Results were consistent across subgroups (gender, age, preadmission diseases, type of admission) and sensitivity analyses (depression and anxiety separately).

CONCLUSIONS

Preadmission use of statins, nonsteroidal anti-inflammatory drugs, glucocorticoids, or combinations did not alter the risk of depression and anxiety after critical illness.

The endocannabinoid system as a target for novel anxiolytic drugs

The endocannabinoid (eCB) system has attracted attention for its role in various behavioral and brain functions, and as a therapeutic target in neuropsychiatric disease states, including anxiety disorders and other conditions resulting from dysfunctional responses to stress. In this mini-review, we highlight components of the eCB system that offer potential 'druggable' targets for new anxiolytic medications, emphasizing some of the less well-discussed options. We discuss how selectively amplifying eCBs recruitment by interfering with eCB-degradation, via fatty acid amide hydrolase (FAAH) and monoacylglycerol lipase (MAGL), has been linked to reductions in anxiety-like behaviors in rodents and variation in human anxiety symptoms. We also discuss a non-canonical route to regulate eCB degradation that involves interfering with cyclooxygenase-2 (COX-2). Next, we discuss approaches to targeting eCB receptor-signaling in ways that do not involve the cannabinoid receptor subtype 1 (CB1R); by targeting the CB2R subtype and the transient receptor potential vanilloid type 1 (TRPV1). Finally, we review evidence that cannabidiol (CBD), while representing a less specific pharmacological approach, may be another way to modulate eCBs and interacting neurotransmitter systems to alleviate anxiety. Taken together, these various approaches provide a range of plausible paths to developing novel compounds that could prove useful for treating trauma-related and anxiety disorders.

Regulation of fear extinction by long-term depression: The roles of endocannabinoids and brain derived neurotrophic factor

The extinction of a conditioned fear response is of great interest in the search for a means of ameliorating adverse neurobiological changes resulting from stress. The discovery that endocannibinoid (EC) levels are inversely related to the extent of such stress, and that the amygdala is a primary site mediating stress, suggests that ECs in this brain region might play a major role in extinction. Supporting this are the observations that the basolateral complex of the amygdala shows an increase in ECs only during extinction and that early clinical trials indicate that cannabinoid-like agents, when taken orally by patients suffering from post traumatic stress disorder (PTSD), reduce insomnia and nightmares. In order to optimize the potential of these agents to ameliorate symptoms of PTSD four important questions need to be answered: first, what is the identity of the cells that release ECs in the amygdala during extinction; second, what are their sites of action; third, what roles do the ECs play in the alleviation of long- depression (LTD), a process central to extinction; and finally, to what extent does brain derived neurotrophic factor (BDNF) facilitate the release of ECs? A review of the relevant literature is presented in an attempt to answer these questions. It is suggested that the principal cell involved in EC synthesis and release during extinction is the so-called excitatory extinction neuron in the basal nucleus of the amygdala. Furthermore that the main site of action of the ECs is the adjacent calcitonin gene-related peptide inhibitory interneurons, whose normal role of blocking the excitatory neurons is greatly diminished. The molecular pathways leading (during extinction trials) to the synthesis and release of ECs from synaptic spines of extinction neurons, that is potentiated by BDNF, are also delineated in this review. Finally, consideration is given to how the autocrine action of BDNF, linked to the release of ECs, can lead to the sustained release of these, so maintaining extinction over long times.

Pharmacological interventions for preventing post-traumatic stress disorder (PTSD)

BACKGROUND

Post-traumatic stress disorder (PTSD) is a debilitating disorder which, after a sufficient delay, may be diagnosed amongst individuals who respond with intense fear, helplessness or horror to traumatic events. There is some evidence that the use of pharmacological interventions immediately after exposure to trauma may reduce the risk of developing of PTSD.

OBJECTIVES

To assess the effects of pharmacological interventions for the prevention of PTSD in adults following exposure to a traumatic event.

SEARCH METHODS

We searched the Cochrane Depression, Anxiety and Neurosis Controlled Trials Register (CCDANCTR-Studies and CCDANCTR-References) (to 14 February 2014). This register contains relevant reports of randomised controlled trials from the following bibliographic databases: CENTRAL (all years); EMBASE (1974 to date); MEDLINE (1950 to date) and PsycINFO (1967 to date). We identified unpublished trials by searching the National Institute of Health (NIH) Reporter, the metaRegister of Controlled Trials database (mRCT) and the WHO International Clinical Trials Registry Platform (to December 2013). We scanned the reference lists of articles for additional studies. We placed no constraints on language and setting.

SELECTION CRITERIA

We restricted studies to randomised controlled trials (RCTs) of pharmacological interventions compared with placebo for the prevention of PTSD in adults.

DATA COLLECTION AND ANALYSIS

Two authors (TA and JI) independently assessed trials for eligibility and inclusion based on the review selection criteria. We independently extracted sample, methodological, outcome and 'Risk of bias' data, as well as the number of side effects, from each trial and entered these into a customised data extraction form. We contacted investigators for missing information. We calculated summary statistics for continuous and dichotomous variables (if provided). We did not undertake subgroup analyses due to the small number of included studies.

MAIN RESULTS

We included nine short-term RCTs (duration 12 weeks or less) in the analysis (345 participants; age range 18 to 76 years). Participants were exposed to a variety of traumas, ranging from assault, traffic accidents and work accidents to cardiac surgery and septic shock. Seven studies were conducted at single centres. The seven RCTs included four hydrocortisone studies, three propranolol studies (of which one study had a third arm investigating gabapentin), and single trials of escitalopram and temazepam. Outcome assessment measures included the Clinician-Administered PTSD Scale (CAPS), the 36-Item Short-Form Health Survey (SF-36) and the Center for Epidemiological Studies - Depression Scale (CES-D).In four trials with 165 participants there was moderate quality evidence for the efficacy of hydrocortisone in preventing the onset of PTSD (risk ratio (RR) 0.17; 95% confidence interval (CI) 0.05 to 0.56; P value = 0.004), indicating that between seven and 13 patients would need to be treated with this agent in order to prevent the onset of PTSD in one patient. There was low quality evidence for preventing the onset of PTSD in three trials with 118 participants treated with propranolol (RR 0.62; 95% CI 0.24 to 1.59; P value = 0.32). Drop-outs due to treatment-emergent side effects, where reported, were low for all of the agents tested. Three of the four RCTs of hydrocortisone reported that medication was more effective than placebo in reducing PTSD symptoms after a median of 4.5 months after the event. None of the single trials of escitalopram, temazepam and gabapentin demonstrated evidence that medication was superior to placebo in preventing the onset of PTSD.Seven of the included RCTs were at a high risk of bias. Differential drop-outs between groups undermined the results of three studies, while one study failed to describe how the allocation of medication was concealed. Other forms of bias that might have influenced study results included possible confounding through group differences in concurrent medication and termination of the study based on treatment response.

AUTHORS' CONCLUSIONS

There is moderate quality evidence for the efficacy of hydrocortisone for the prevention of PTSD development in adults. We found no evidence to support the efficacy of propranolol, escitalopram, temazepam and gabapentin in preventing PTSD onset. The findings, however, are based on a few small studies with multiple limitations. Further research is necessary in order to determine the efficacy of pharmacotherapy in preventing PTSD and to identify potential moderators of treatment effect.

Reductions in circulating endocannabinoid levels in individuals with post-traumatic stress disorder following exposure to the World Trade Center attacks

Endocannabinoid (eCB) signaling has been identified as a modulator of adaptation to stress, and is integral to basal and stress-induced glucocorticoid regulation. Furthermore, interactions between eCBs and glucocorticoids have been shown to be necessary for the regulation of emotional memories, suggesting that eCB function may relate to the development of post-traumatic stress disorder (PTSD). To examine this, plasma eCBs were measured in a sample (n=46) drawn from a population-based cohort selected for physical proximity to the World Trade Center (WTC) at the time of the 9/11 attacks. Participants received a structured diagnostic interview and were grouped according to whether they met diagnostic criteria for PTSD (no PTSD, n=22; lifetime diagnosis of PTSD=24). eCB content (2-arachidonoylglycerol (2-AG) and anandamide (AEA)) and cortisol were measured from 8 a.m. plasma samples. Circulating 2-AG content was significantly reduced among individuals meeting diagnostic criteria for PTSD. The effect of reduced 2-AG content in PTSD remained significant after controlling for the stress of exposure to the WTC collapse, gender, depression and alcohol abuse. There were no significant group differences for AEA or cortisol levels; however, across the whole sample AEA levels positively correlated with circulating cortisol, and AEA levels exhibited a negative relationship with the degree of intrusive symptoms within the PTSD sample. This report shows that PTSD is associated with a reduction in circulating levels of the eCB 2-AG. Given the role of 2-AG in the regulation of the stress response, these data support the hypothesis that deficient eCB signaling may be a component of the glucocorticoid dysregulation associated with PTSD. The negative association between AEA levels and intrusive symptoms is consistent with animal data indicating that reductions in AEA promote retention of aversive emotional memories. Future work will aim to replicate these findings and extend their relevance to clinical pathophysiology, as well as to neuroendocrine and molecular markers of PTSD.

Translational evidence for the involvement of the endocannabinoid system in stress-related psychiatric illnesses

Accumulating evidence over the past decade has highlighted an important role of the endocannabinoid (eCB) system in the regulation of stress and emotional behavior across divergent species, from rodents to humans. The general findings from this work indicate that the eCB system plays an important role in gating and buffering the stress response, dampening anxiety and regulating mood. Work in rodents has allowed researchers to determine the neural mechanisms mediating this relationship while work in human populations has demonstrated the possible importance of this system in stress-related psychiatric diseases, such as post-traumatic stress disorder, generalized anxiety and major depression. These stress-protective effects of eCB signaling appear to be primarily mediated by their actions within corticolimbic structures, particularly the amygdala and the prefrontal cortex. The aim of this review is to provide an up-to-date discussion of the current level of knowledge in this field, as well as address the current gaps in knowledge and specific areas of research that require attention.

Plasma concentrations of endocannabinoids and related primary fatty acid amides in patients with post-traumatic stress disorder

Background

Endocannabinoids (ECs) and related N-acyl-ethanolamides (NAEs) play important roles in stress response regulation, anxiety and traumatic memories. In view of the evidence that circulating EC levels are elevated under acute mild stressful conditions in humans, we hypothesized that individuals with traumatic stress exposure and post-traumatic stress disorder (PTSD), an anxiety disorder characterized by the inappropriate persistence and uncontrolled retrieval of traumatic memories, show measurable alterations in plasma EC and NAE concentrations.

Methods

We determined plasma concentrations of the ECs anandamide (ANA) and 2-arachidonoylglycerol (2-AG) and the NAEs palmitoylethanolamide (PEA), oleoylethanolamide (OEA), stearoylethanolamine (SEA), and N-oleoyldopamine (OLDA) by HPLC-MS-MS in patients with PTSD (n = 10), trauma-exposed individuals without evidence of PTSD (n = 9) and in healthy control subjects (n = 29). PTSD was diagnosed according to DSM-IV criteria by administering the Clinician Administered PTSD Scale (CAPS), which also assesses traumatic events.

Results

Individuals with PTSD showed significantly higher plasma concentrations of ANA (0.48±0.11 vs. 0.36±0.14 ng/ml, p = 0.01), 2-AG (8.93±3.20 vs. 6.26±2.10 ng/ml, p<0.01), OEA (5.90±2.10 vs. 3.88±1.85 ng/ml, p<0.01), SEA (2.70±3.37 vs. 0.83±0.47, ng/ml, p<0.05) and significantly lower plasma levels of OLDA (0.12±0.05 vs. 0.45±0.59 ng/ml, p<0.05) than healthy controls. Moreover, PTSD patients had higher 2-AG plasma levels (8.93±3.20 vs. 6.01±1.32 ng/ml, p = 0.03) and also higher plasma concentrations of PEA (4.06±1.87 vs. 2.63±1.34 ng/ml, p<0.05) than trauma-exposed individuals without evidence of PTSD. CAPS scores in trauma-exposed individuals with and without PTSD (n = 19) correlated positively with PEA (r = 0.55, p = 0.02) and negatively with OLDA plasma levels (r = −0.68, p<0.01). CAPS subscores for intrusions (r = −0.65, p<0.01), avoidance (r = −0.60, p<0.01) and hyperarousal (r = −0.66, p<0.01) were all negatively related to OLDA plasma concentrations.

Conclusions

PTSD appears to be associated with changes in plasma EC/NAE concentrations. This may have pathophysiological and diagnostic consequences but will need to be reproduced in larger cohorts.

A genotype-specific, randomized controlled behavioral intervention to improve the neuroemotional outcome of cardiac surgery: study protocol for a randomized controlled trial

Background

Cardiac surgery is one of the most commonly performed surgical procedures worldwide with >700,000 surgeries in 2006 in the US alone. Cardiac surgery results in a considerable exposure to physical and emotional stress; stress-related disorders such as depression or post-traumatic stress disorder are the most common adverse outcomes of cardiac surgery, seen in up to 20% of patients. Using information from a genome-wide association study to characterize genetic effects on emotional memory, we recently identified a single nucleotide polymorphism of the glucocorticoid receptor gene (the Bcll single nucleotide polymorphism) as a significant genetic risk factor for traumatic memories from cardiac surgery and symptoms of post-traumaticstress disorder. The Bcll high-risk genotype (Bcll GG) has a prevalence of 16.6% in patients undergoing cardiac surgery and is associated with increased glucocorticoid receptor signaling under stress. Concomitant animal experiments have confirmed an essential role of glucocorticoid receptor activation for traumatic memory formation during stressful experiences. Early cognitive behavioral intervention has been shown to prevent stress-related disorders after heart surgery.

Methods/Design

The proposed study protocol is based on the above mentioned earlier findings from animal experiments and preclinical studies in volunteers. Patients (n = 872) will be genotyped for the Bcll single nucleotide polymorphism before surgery, which should result in 120 homozygous high-risk carriers of the Bcll GG allele and 240 randomly selected low-risk heterozygous or non-carriers of the single nucleotide polymorphism. All patients will then undergo randomization to either cognitive behavioral intervention or a control intervention consisting of non-specific general information about the role of stress in heart disease. The primary efficacy endpoint will be post-traumatic stress levels at one year after surgery as determined by a standardized questionnaire that has been specifically validated in patients after critical illness.

Discussion

The proposed randomized controlled trial intends to demonstrate that a preoperatively administered minimal cognitive behavioral intervention targeted to homozygous carriers of the Bcll *G high-risk allele reduces traumatic memories and post-traumatic stress disorder symptoms after heart surgery to a level seen in non-carriers of the mutation, and thus improves the neuroemotional outcome of cardiac surgery.

Trial registration number

The trial will be registered at http://www.clinicaltrials.gov/ before commencing with the study.