Effects of etomidate on complications related to intubation and on mortality in septic shock patients treated with hydrocortisone: a propensity score analysis

Current trends in emergency airway management: a clinical review

Airway management is a fundamental and complex process that involves a sequence of integrated tasks. Situations requiring emergency airway management may occur in the emergency department, intensive care units, and various other clinical spaces. A variety of challenges can arise during emergency airway preparation, intubation, and postintubation, which may result in significant complications for patients. Therefore, many countries are establishing step-by-step systemization and detailed guidelines and/or updating their content based on the latest research. This clinical review introduces the current trends in emergency airway management, such as emergency airway management algorithms, comparison of video and direct laryngoscopy, rapid sequence intubation, pediatric airway management, prehospital airway management, surgical airway management, and airway management education.

How to improve intubation in the intensive care unit. Update on knowledge and devices

Tracheal intubation in the critically ill is associated with serious complications, mainly cardiovascular collapse and severe hypoxemia. In this narrative review, we present an update of interventions aiming to decrease these complications. MACOCHA is a simple score that helps to identify patients at risk of difficult intubation in the intensive care unit (ICU). Preoxygenation combining the use of inspiratory support and positive end-expiratory pressure should remain the standard method for preoxygenation of hypoxemic patients. Apneic oxygenation using high-flow nasal oxygen may be supplemented, to prevent further hypoxemia during tracheal intubation. Face mask ventilation after rapid sequence induction may also be used to prevent hypoxemia, in selected patients without high-risk of aspiration. Hemodynamic optimization and management are essential before, during and after the intubation procedure. All these elements can be integrated in a bundle. An airway management algorithm should be adopted in each ICU and adapted to the needs, situation and expertise of each operator. Videolaryngoscopes should be used by experienced operators.

Endotracheal intubation sedation in the intensive care unit

Endotracheal intubation is one of the most common, yet most dangerous procedure performed in the intensive care unit (ICU). Complications of ICU intubations include severe hypotension, hypoxemia, and cardiac arrest. Multiple observational studies have evaluated risk factors associated with these complications. Among the risk factors identified, the choice of sedative agents administered, a modifiable risk factor, has been reported to affect these complications (hypotension). Propofol, etomidate, and ketamine or in combination with benzodiazepines and opioids are commonly used sedative agents administered for endotracheal intubation. Propofol demonstrates rapid onset and offset, however, has drawbacks of profound vasodilation and associated cardiac depression. Etomidate is commonly used in the critically ill population. However, it is known to cause reversible inhibition of 11 β-hydroxylase which suppresses the adrenal production of cortisol for at least 24 h. This added organ impairment with the use of etomidate has been a potential contributing factor for the associated increased morbidity and mortality observed with its use. Ketamine is known to provide analgesia with sedation and has minimal respiratory and cardiovascular effects. However, its use can lead to tachycardia and hypertension which may be deleterious in a patient with heart disease or cause unpleasant hallucinations. Moreover, unlike propofol or etomidate, ketamine requires organ dependent elimination by the liver and kidney which may be problematic in the critically ill. Lately, a combination of ketamine and propofol, “Ketofol”, has been increasingly used as it provides a balancing effect on hemodynamics without any of the side effects known to be associated with the parent drugs. Furthermore, the doses of both drugs are reduced. In situations where a difficult airway is anticipated, awake intubation with the help of a fiberoptic scope or video laryngoscope is considered. Dexmedetomidine is a commonly used sedative agent for these procedures.

Comparison of etomidate and propofol-mediated anesthesia induction followed by intubation and sevoflurane maintenance during ERCP in obese patients

OBJECTIVE

In this study, we focused on obese patients (Body Mass Index (BMI) ≥30 kg/m²) and compared the efficacy and safety of etomidate or propofol-mediated anesthesia induction followed by intubation and sevoflurane maintenance during endoscopic retrograde cholangiopancreatography (ERCP).

METHODS

A total of 180 patients were computer-randomized into a propofol group or an etomidate group, with 90 cases in each group. Patients received anesthesia induction by etomidate or propofol followed by intubation and sevoflurane maintenance during ERCP. Baseline characteristics, information about procedure-related time and satisfaction, and adverse events were collected and compared between the etomidate group and propofol group.

RESULTS

Baseline characteristics of both groups were similar. The propofol group had a longer time of intraoperative SpO₂ <95% (etomidate group vs propofol group, 0.07±0.47 min vs 0.24±0.87 min, P-value = 0.019), higher frequency of SpO₂ <95% for any period of time (etomidate group vs propofol group, 2.22% vs 11.11%, P-value = 0.032), and higher frequency of transient hypotension (etomidate group vs propofol group, 1.11% vs 8.89%, P-value = 0.034). The etomidate group had longer induction time and recovery time than the propofol group with P-values of 0.019 and 0.004, respectively.

CONCLUSION

In obese patients who underwent ERCP and needed intubation, etomidate appears better than propofol for anesthesia induction followed by anesthesia maintenance of sevoflurane.

Infectious Complications after Etomidate vs. Propofol for Induction of General Anesthesia in Cardiac Surgery-Results of a Retrospective, before-after Study

Background: Etomidate is typically used as an induction agent in cardiac surgery because it has little impact on hemodynamics. It is a known suppressor of adrenocortical function and may increase the risk for post-operative infections, sepsis, and mortality. The aim of this study was to evaluate whether etomidate increases the risk of postoperative sepsis (primary outcome) and infections (secondary outcome) compared to propofol. Methods: This was a retrospective before–after trial (IRB EA1/143/20) performed at a tertiary medical center in Berlin, Germany, between 10/2012 and 01/2015. Patients undergoing cardiac surgery were investigated within two observation intervals, during which etomidate and propofol were the sole induction agents. Results: One-thousand, four-hundred, and sixty-two patients, and 622 matched pairs, after caliper propensity-score matching, were included in the final analysis. Sepsis rates did not differ in the matched cohort (etomidate: 11.5% vs. propofol: 8.2%, p = 0.052). Patients in the etomidate interval were more likely to develop hospital-acquired pneumonia (etomidate: 18.6% vs. propofol: 14.0%, p = 0.031). Conclusion: Our study showed that a single-dose of etomidate is not statistically associated with higher postoperative sepsis rates after cardiac surgery, but is associated with a higher incidence of hospital-acquired pneumonia. However, there is a notable trend towards a higher sepsis rate.

Emergency Airway Management Outside the Operating Room: Current Evidence and Management Strategies

Emergency airway management outside the operating room (OR) is often associated with an increased risk of airway related, as well as cardiopulmonary, complications which can impact morbidity and mortality. These emergent airways may take place in the intensive care unit (ICU), where patients are critically ill with minimal physiological reserve, or other areas of the hospital where advanced equipment and personnel are often unavailable. As such, emergency airway management outside the OR requires expertise at manipulation of not only the anatomically difficult airway but also the physiologically and situationally difficult airway. Adequate preparation and appropriate use of airway management techniques are important to prevent complications. Judicious utilization of pre- and apneic oxygenation is important as is the choice of medications to facilitate intubation in this at-risk population. Recent study in critically ill patients has shown that postintubation hemodynamic and respiratory compromise is common, independently associated with poor outcomes and can be impacted by the choice of drugs and techniques used. In addition to adequately preparing for a physiologically difficult airway, enhancing the ability to predict an anatomically difficult airway is essential in reducing complication rates. The use of artificial intelligence in the identification of difficult airways has shown promising results and could be of significant advantage in uncooperative patients as well as those with a questionable airway examination. Incorporating this technology and understanding the physiological, anatomical, and logistical challenges may help providers better prepare for managing such precarious airways and lead to successful outcomes. This review discusses the various challenges associated with airway management outside the OR, provides guidance on appropriate preparation, airway management skills, medication use, and highlights the role of a coordinated multidisciplinary approach to out-of-OR airway management.

Propofol, Ketamine, and Etomidate as Induction Agents for Intubation and Outcomes in Critically Ill Patients: A Retrospective Cohort Study

Propofol, ketamine, and etomidate are common anesthetic agents for induction of anesthesia in the ICU. The choice between these agents is complex and may not depend solely upon severity of illness.

OBJECTIVES

To evaluate the association between the administration of propofol, ketamine, and etomidate and ICU, hospital mortality, and length of stay.

DESIGN SETTING AND PARTICIPANTS

Retrospective single-center cohort study. ICUs in a tertiary medical center, between January 01, 2012, and December 31, 2017. Critically ill adult patients given a single IV anesthetic for intubation.

MAIN OUTCOME AND MEASURES

Primary outcomes were ICU and hospital mortality. Secondary outcomes were ICU- and hospital-free days through 28 days. An inverse probability of treatment weighed approach was used. The propensity score was estimated using a generalized logit model as a function of patient characteristics, admission source, ICU type, readmission status, length of ICU stays prior to intubation, and acute physiology score. Mortality outcomes were assessed with weighted logistic regression and -free days assessed by weighted linear regression with Bonferroni correction for pairwise comparisons.

RESULTS

Of 2,673 patients, 36% received propofol, 30% ketamine and 34% etomidate. Overall ICU and hospital mortality were 19% and 29%, respectively. Patients given ketamine had higher odds of ICU mortality (1.45; [95% CI, 1.07-1.94]; p = 0.015) and patients given etomidate had higher odds of ICU mortality (1.87; 1.40-2.49; p < 0.001), hospital mortality (1.43; 1.09-1.86; p = 0.009), and less ICU-free days (-2.10; -3.21 to -1.00; p < 0.001) than those given propofol. Patients given ketamine and etomidate had similar odds of hospital mortality (1.06; 0.80-1.42; p = 0.761) and similar hospital-free days (0.30; -0.81 to 1.40; p = 0.600).

CONCLUSIONS AND RELEVANCE

Compared with ketamine and etomidate, propofol was associated with better outcome in critically ill patients undergoing anesthesia for intubation. Even after adjusting for severity of illness prior to intubation, residual confounders cannot be excluded.

Etomidate Use Is Associated With Less Hypotension Than Ketamine for Emergency Department Sepsis Intubations: A NEAR Cohort Study

OBJECTIVE

The objectives of this study were 1) to describe the current use of etomidate and other induction agents in patients with sepsis and 2) to compare adverse events between etomidate and ketamine in sepsis.

METHODS

This was an observational cohort study of the prospective National Emergency Airway Registry (NEAR) data set. Descriptive statistics were used to report the distribution of induction agents used in patients with sepsis. Adverse events were compared using bivariate analysis, and a sensitivity analysis was conducted using a propensity score-adjusted analysis of etomidate versus ketamine.

RESULTS

A total of 531 patients were intubated for sepsis, and the majority (71%) were intubated with etomidate as the initial induction agent. Etomidate was less frequently used in sepsis patients than nonsepsis patients (71% vs. 85%, odds ratio [OR] = 0.4, 95% confidence interval [CI] = 0.4 to 0.5). Sepsis patients had a greater risk of adverse events, and vasopressor therapy was required for 25% of patients after intubation. Postprocedure hypotension was higher between those intubated for sepsis with ketamine versus etomidate (74% vs. 50%, OR = 2.9, 95% CI = 1.9 to 4.5). After confounding by indication in the propensity score-adjusted analysis was accounted for, ketamine was associated with more postprocedure hypotension (OR = 2.7, 95% CI = 1.1 to 6.7). No difference in emergency department deaths was observed.

CONCLUSIONS

Etomidate is used less frequently in sepsis patients than nonsepsis patients, with ketamine being the most frequently used alternative. Ketamine was associated with more postprocedural hypotension than etomidate. Future clinical trials are needed to determine the optimal induction agent in patients with sepsis.

Corticosteroid receptor rebalancing alleviates critical illness-related corticosteroid insufficiency after traumatic brain injury by promoting paraventricular nuclear cell survival via Akt/CREB/BDNF signaling

BACKGROUND

We previously found that high-dose methylprednisolone increased the incidence of critical illness-related corticosteroid insufficiency (CIRCI) and mortality in rats with traumatic brain injury (TBI), whereas low-dose hydrocortisone but not methylprednisolone exerted protective effects. However, the receptor-mediated mechanism remains unclear. This study investigated the receptor-mediated mechanism of the opposite effects of different glucocorticoids on the survival of paraventricular nucleus (PVN) cells and the incidence of CIRCI after TBI.

METHODS

Based on controlled cortical impact (CCI) and treatments, male SD rats (n = 300) were randomly divided into the sham, CCI, CCI + GCs (methylprednisolone 1 or 30 mg/kg/day; corticosterone 1 mg/kg/day), CCI + methylprednisolone+RU486 (RU486 50 mg/kg/day), and CCI + corticosterone+spironolactone (spironolactone 50 mg/kg/day) groups. Blood samples were collected 7 days before and after CCI. Brain tissues were collected on postinjury day 7 and processed for histology and western blot analysis.

RESULTS

We examined the incidence of CIRCI, mortality, apoptosis in the PVN, the receptor-mediated mechanism, and downstream signaling pathways on postinjury day 7. We found that methylprednisolone and corticosterone exerted opposite effects on the survival of PVN cells and the incidence of CIRCI by activating different receptors. High-dose methylprednisolone increased the nuclear glucocorticoid receptor (GR) level and subsequently increased cell loss in the PVN and the incidence of CIRCI. In contrast, low-dose corticosterone but not methylprednisolone played a protective role by upregulating mineralocorticoid receptor (MR) activation. The possible downstream receptor signaling mechanism involved the differential effects of GR and MR on the activity of the Akt/CREB/BDNF pathway.

CONCLUSION

The excessive activation of GR by high-dose methylprednisolone exacerbated apoptosis in the PVN and increased CIRCI. In contrast, refilling of MR by corticosterone protects PVN neurons and reduces the incidence of CIRCI by promoting GR/MR rebalancing after TBI.

Risk factors for corticosteroid insufficiency during the sub-acute phase of acute traumatic brain injury

Hypothalamic-pituitary-adrenal axis dysfunction may lead to the occurrence of critical illness-related corticosteroid insufficiency. Critical illness-related corticosteroid insufficiency can easily occur after traumatic brain injury, but few studies have examined this occurrence. A multicenter, prospective, cohort study was performed to evaluate the function of the hypothalamic-pituitary-adrenal axis and the incidence of critical illness-related corticosteroid insufficiency during the sub-acute phase of traumatic brain injury. One hundred and forty patients with acute traumatic brain injury were enrolled from the neurosurgical departments of three tertiary-level hospitals in China, and the critical illness-related corticosteroid insufficiency incidence, critical-illness-related corticosteroid insufficiency-related risk factors, complications, and 28-day mortality among these patients was recorded. Critical illness-related corticosteroid insufficiency was diagnosed in patients with plasma total cortisol levels less than 10 μg/dL (275.9 nM) on post-injury day 4 or when serum cortisol was insufficiently suppressed (less than 50%) during a dexamethasone suppression test on post-injury day 5. The results demonstrated that critical illness-related corticosteroid insufficiency occurred during the sub-acute phase of traumatic brain injury in 5.6% of patients with mild injury, 22.5% of patients with moderate injury, and 52.2% of patients with severe injury. Traumatic brain injury-induced critical illness-related corticosteroid insufficiency was strongly correlated to injury severity during the sub-acute stage of traumatic brain injury. Traumatic brain injury patients with critical illness-related corticosteroid insufficiency frequently presented with hemorrhagic cerebral contusions, diffuse axonal injury, brain herniation, and hypotension. Differences in the incidence of hospital-acquired pneumonia, gastrointestinal bleeding, and 28-day mortality were observed between patients with and without critical illness-related corticosteroid insufficiency during the sub-acute phase of traumatic brain injury. Hypotension, brain-injury severity, and the types of traumatic brain injury were independent risk factors for traumatic brain injury-induced critical illness-related corticosteroid insufficiency. These findings indicate that critical illness-related corticosteroid insufficiency is common during the sub-acute phase of traumatic brain injury and is strongly associated with poor prognosis. The dexamethasone suppression test is a practical assay for the evaluation of hypothalamic-pituitary-adrenal axis function and for the diagnosis of critical illness-related corticosteroid insufficiency in patients with traumatic brain injury, especially those with hypotension, hemorrhagic cerebral contusions, diffuse axonal injury, and brain herniation. Sub-acute infection of acute traumatic brain injury may be an important factor associated with the occurrence and development of critical illness-related corticosteroid insufficiency. This study protocol was approved by the Ethics Committee of General Hospital of Tianjin Medical University, China in December 2011 (approval No. 201189).

Critical Care Management: Sepsis and Disseminated and Local Infections

Local and systemic infections are a significant cause of morbidity and mortality among immunocompromised children, including but not limited to patients with hematologic and solid malignancies, congenital or acquired immunodeficiencies, or hematopoietic cell or solid organ transplantation patients. Progression to septic shock can be rapid and profound and thus requires specific diagnostic and treatment approaches. This chapter will discuss the diagnosis and the initial hemodynamic management strategies of septic shock in immunocompromised children, including strategies to improve oxygen delivery, reduce metabolic demand, and monitor hemodynamic response to resuscitation. This chapter also discusses strategies to reverse septic shock pathobiology, including the use of both empiric and targeted anti-infective strategies and pharmacologic and cell therapy-based immunomodulation. Specific consideration is also paid to the management of high-risk subpopulations and the care of septic shock patients with resolving injury.

Neuroendocrine Derangements in Early Septic Shock: Pharmacotherapy for Relative Adrenal and Vasopressin Insufficiency

Septic shock is a leading cause of mortality in intensive care units throughout the world. While this disease state represents a highly complex pathophysiology involving numerous organ systems, the early approach to care includes adequate hemodynamic support traditionally achieved via infusions of vasoactive medications after adequate fluid resuscitation. Relative adrenal and vasopressin deficiencies are a common feature of septic shock that contribute to impaired hemodynamics. Hydrocortisone and vasopressin are endocrine system hormone analogues that target the acute neuroendocrine imbalance associated with septic shock. This clinically focused annotated review describes the pathophysiological mechanisms behind their use and explores the potential clinical roles of early administration and synergy when combined.

Incidence of and risk factors for severe cardiovascular collapse after endotracheal intubation in the ICU: a multicenter observational study

Introduction

Severe cardiovascular collapse (CVC) is a life-threatening complication after emergency endotracheal intubation (ETI) in the ICU. Many factors may interact with hemodynamic conditions during ETI, but no study to date has focused on factors associated with severe CVC occurrence. This study assessed the incidence of severe CVC after ETI in the ICU and analyzed the factors predictive of severe CVC.

Methods

This was a secondary analysis of a prospective multicenter study of 1,400 consecutive intubations at 42 ICUs. The incidence of severe CVC was assessed in patients who were hemodynamically stable (mean arterial blood pressure >65 mmHg without vasoactive drugs) before intubation, and the factors predictive of severe CVC were determined by multivariate analysis based on patient and procedure characteristics.

Results

Severe CVC occurred following 264 of 885 (29.8 %) intubation procedures. A two-step multivariate analysis showed that independent risk factors for CVC included simple acute physiologic score II regardless of age (odds ratio (OR) 1.02, p < 0.001), age 60–75 years (OR 1.96, p < 0.002 versus <60 years) and >75 years (OR 2.81, p < 0.001 versus <60 years), acute respiratory failure as a reason for intubation (OR 1.51, p = 0.04), first intubation in the ICU (OR 1.61, p = 0.02), noninvasive ventilation as a preoxygenation method (OR 1.54, p = 0.03) and inspired oxygen concentration >70 % after intubation (OR 1.91, p = 0.001). Comatose patients who required ETI were less likely to develop CVC during intubation (OR 0.48, p = 0.004).

Conclusions

CVC is a frequent complication, especially in old and severely ill patients intubated for acute respiratory failure in the ICU. Specific bundles to prevent CVC may reduce morbidity and mortality related to intubation of these high-risk, critically ill patients.

Trial registration

clinicaltrials.gov NCT01532063; registered 8 February 2012.

Single-dose etomidate does not increase mortality in patients with sepsis: a systematic review and meta-analysis of randomized controlled trials and observational studies

BACKGROUND

The effect of single-dose etomidate on mortality in patients with sepsis remains controversial. We systematically reviewed the literature to investigate whether a single dose of etomidate for rapid sequence intubation increased mortality in patients with sepsis.

METHODS

PubMed, Embase, and CENTRAL (Cochrane Central Register of Controlled Trials) were searched for randomized controlled trials (RCTs) and observational studies regarding the effect of single-dose etomidate on mortality in adults with sepsis. The primary outcome was all-cause mortality. The Mantel-Haenszel method with random-effects modeling was used to calculate pooled relative risks (RRs) and 95% CIs.

RESULTS

Eighteen studies (two RCTs and 16 observational studies) in 5,552 patients were included. Pooled analysis suggested that single-dose etomidate was not associated with increased mortality in patients with sepsis in both the RCTs (RR, 1.20; 95% CI, 0.84-1.72; P = .31; I(2) = 0%) and the observational studies (RR, 1.05; 95% CI, 0.97-1.13; P = .23; I(2) = 25%). When only adjusted RRs were pooled in five observational studies, RR for mortality was 1.05 (95% CI, 0.79-1.39; P = .748; I(2) = 71.3%). These findings also were consistent across all subgroup analyses for observational studies. Single-dose etomidate increased the risk of adrenal insufficiency in patients with sepsis (eight studies; RR, 1.42; 95% CI, 1.22-1.64; P < .00001).

CONCLUSIONS

Current evidence indicates that single-dose etomidate does not increase mortality in patients with sepsis. However, this finding largely relies on data from observational studies and is potentially subject to selection bias; hence, high-quality and adequately powered RCTs are warranted.

Difficult intubation in obese patients: incidence, risk factors, and complications in the operating theatre and in intensive care units

BACKGROUND

Intubation procedure in obese patients is a challenging issue both in the intensive care unit (ICU) and in the operating theatre (OT). The objectives of the study were (i) to compare the incidence of difficult intubation and (ii) its related complications in obese patients admitted to ICU and OT.

METHODS

We conducted a multicentre prospective observational cohort study in ICU and OT in obese (BMI≥30 kg m(-2)) patients. The primary endpoint was the incidence of difficult intubation. Secondary endpoints were the risk factors for difficult intubation, the use of difficult airway management techniques, and severe life-threatening complications related to intubation (death, cardiac arrest, severe hypoxaemia, severe cardiovascular collapse).

RESULTS

In cohorts of 1400 and 11 035 consecutive patients intubated in ICU and in the OT, 282 (20%) and 2103 (19%) were obese. In obese patients, the incidence of difficult intubation was twice more frequent in ICU than in the OT (16.3% vs 8.2%, P<0.01). In both cohorts, risk factors for difficult intubation were Mallampati score III/IV, obstructive sleep apnoea syndrome, and reduced mobility of cervical spine, while limited mouth opening, severe hypoxaemia, and coma appeared only in ICU. Specific difficult airway management techniques were used in 66 (36%) cases of difficult intubation in obese patients in the OT and in 10 (22%) cases in ICU (P=0.04). Severe life-threatening complications were significantly more frequent in ICU than in the OT (41.1% vs 1.9%, relative risk 21.6, 95% confidence interval 15.4-30.3, P<0.01).

CONCLUSIONS

In obese patients, the incidence of difficult intubation was twice more frequent in ICU than in the OT and severe life-threatening complications related to intubation occurred 20-fold more often in ICU.

CLINICAL TRIAL REGISTRATION

Current controlled trials. Identifier: NCT01532063.

Etomidate for anesthesia induction: friends or foe in major cardiac surgery?

Use of etomidate for anesthesia induction is still debated. In the previous issue of Critical Care, Heinrich and colleagues reported that etomidate for anesthesia induction had similar outcome in comparison with other drugs, in a specific population of 3,054 patients ahead of major cardiac surgery. For the authors, the similar outcomes for mortality and length of hospital stay add to the hemodynamic stability and the improved intubation conditions to support keeping etomidate in the emergency drugs armamentarium for induction of anesthesia in patients at risk of hemodynamic failure. This commentary reviews the results and implications of their study.

Do the observational studies using propensity score analysis agree with randomized controlled trials in the area of sepsis?

BACKGROUND AND OBJECTIVES

Sepsis is a leading cause of mortality and morbidity in the intensive care unit, and many studies have been conducted aiming to improve its outcome. Randomized controlled trials (RCTs) and observational studies using propensity score (PS) method are commonly used for this purpose. However, the agreement between these two major methodological designs has never been investigated in this specific area. The present study aimed to compare the effect sizes between RCTs and PS-based studies.

METHODS

Electronic databases including Pubmed, Scopus, and EBSCO were searched to obtain PS-based studies in the area of sepsis. The studies were matched to RCTs or systematic reviews and meta-analysis in terms of population, intervention, control, and outcome. When there were multiple PS-based studies or RCTs in one area, the effect sizes were pooled by using random-effects model and inverse variance method. The comparisons were performed by using differences in the effect size.

RESULTS

A total of 8 topics were identified fulfilling the criterion that at least 1 pair of RCT and PS-based study could be matched. The interventions included activated protein C, low-dose steroid, antithrombin III, combination antibiotic therapy, fish oil supplementation, statin, etomidate for intubation, and recombinant human soluble thrombomodulin. The effect sizes were statistically different between RCTs and PS-based studies in most circumstances (6/8). The pooled mean difference in effect sizes was -0.16 (95% confidence interval, -0.33 to 0.01), indicating a trend towards larger treatment effect in PS studies than in RCTs. The result remains unaltered by restricting to RCTs and PS studies with the largest sample sizes.

CONCLUSION

Our study shows that PS studies tend to report larger treatment effect than RCTs in the field of sepsis, indicating the difference between efficacy trials and effectiveness studies.

Observational studies using propensity score analysis underestimated the effect sizes in critical care medicine

BACKGROUND AND OBJECTIVE

Propensity score (PS) analysis has been increasingly used in critical care medicine; however, its validation has not been systematically investigated. The present study aimed to compare effect sizes in PS-based observational studies vs. randomized controlled trials (RCTs) (or meta-analysis of RCTs).

METHODS

Critical care observational studies using PS were systematically searched in PubMed from inception to April 2013. Identified PS-based studies were matched to one or more RCTs in terms of population, intervention, comparison, and outcome. The effect sizes of experimental treatments were compared for PS-based studies vs. RCTs (or meta-analysis of RCTs) with sign test. Furthermore, ratio of odds ratio (ROR) was calculated from the interaction term of treatment × study type in a logistic regression model. A ROR < 1 indicates greater benefit for experimental treatment in RCTs compared with PS-based studies. RORs of each comparison were pooled by using meta-analytic approach with random-effects model.

RESULTS

A total of 20 PS-based studies were identified and matched to RCTs. Twelve of the 20 comparisons showed greater beneficial effect for experimental treatment in RCTs than that in PS-based studies (sign test P = 0.503). The difference was statistically significant in four comparisons. ROR can be calculated from 13 comparisons, of which four showed significantly greater beneficial effect for experimental treatment in RCTs. The pooled ROR was 0.71 (95% CI: 0.63, 0.79; P = 0.002), suggesting that RCTs (or meta-analysis of RCTs) were more likely to report beneficial effect for the experimental treatment than PS-based studies. The result remained unchanged in sensitivity analysis and meta-regression.

CONCLUSION

In critical care literature, PS-based observational study is likely to report less beneficial effect of experimental treatment compared with RCTs (or meta-analysis of RCTs).

Comparison of clinical outcome variables in patients with and without etomidate-facilitated anesthesia induction ahead of major cardiac surgery: a retrospective analysis

Introduction

It is well known that etomidate may cause adrenal insufficiency. However, the clinical relevance of adrenal suppression after a single dose of etomidate remains vague. The aim of this study was to investigate the association between the administration of a single dose of etomidate or an alternative induction regime ahead of major cardiac surgery and clinical outcome parameters associated with adrenal suppression and onset of sepsis.

Methods

The anesthesia and intensive care unit (ICU) records from patients undergoing cardiac surgery over five consecutive years (2008 to 2012) were retrospectively analyzed. The focus of the analysis was on clinical parameters like mortality, ventilation hours, renal failure, and sepsis-linked serum parameters. Multivariate analysis and Cox regression were applied to derive the results.

Results

In total, 3,054 patient records were analyzed. A group of 1,775 (58%) patients received a single dose of etomidate; 1,279 (42%) patients did not receive etomidate at any time. There was no difference in distribution of age, American Society of Anesthesiologists physical score, duration of surgery, and Acute Physiology and Chronic Health Evaluation II score. Postoperative data showed no significant differences between the two groups in regard to mortality (6.8% versus 6.4%), mean of mechanical ventilation hours (21.2 versus 19.7), days in the ICU (2.6 versus 2.5), hospital days (18.7 versus 17.4), sepsis-associated parameters, Sequential Organ Failure Assessment score, and incidence of renal failure. Administration of etomidate showed no significant influence (P = 0.6) on hospital mortality in the multivariate Cox analysis.

Conclusions

This study found no evidence for differences in key clinical outcome parameters based on anesthesia induction with or without administration of a single dose of etomidate. In consequence, etomidate might remain an acceptable option for single-dose anesthesia induction.

The incidence of critical-illness-related-corticosteroid-insufficiency is associated with severity of traumatic brain injury in adult rats

Traumatic brain injury (TBI) causes deleterious critical-illness-related-corticosteroid-insufficiency (CIRCI), leading to high mortality and morbidity. However, the incidence of CIRCI following different TBI severities is not fully defined. This study was designed to investigate mechanistically the effects of injury severity on corticosteroid response and the development of CIRCI in a rat model of experimentally controlled TBI. Adult male Wistar rats were randomly assigned to sham, mild injury, moderate injury or severe injury groups. TBI was induced using a fluid percussion device at magnitudes of 1.2-1.4 atm (mild injury), 2.0-2.2 atm (moderate injury), and 3.2-3.5 atm (severe injury). We first assessed the effects of injury severity on the mortality and CIRCI occurrence using electrical stimulation test to assess corticosteroid response. We also investigated a series of pathological changes in the hypothalamus, especially in the paraventricular nuclei (PVN), among different injury group including: apoptosis detected by a TUNEL assay, blood-brain-barrier (BBB) permeability assessed by brain water content and Evans Blue extravasation into the cerebral parenchyma, and BBB integrity evaluated by CD31 and Claudin-5 expression and transmission electron microscopy. We made the following observations. First, 6.7% of mild-injured, 13.3% of moderate-injured, and 68.8% of severe-injured rats developed CIRCI, with a peak incidence on post-injury day 7. Second, TBI-induced CIRCI is closely correlated with injury severity. As the injury severity rises both the incidence of CIRCI and mortality surge; Third, increased level of injury severity reduces the expression of endothelial tight junction protein, aggravate BBB permeability and exacerbate the ensuing neural apoptosis in the PVN of hypothalamus. These findings indicate that increased severity of TBI aggravate the incidence of CIRCI by causing damage to tight junctions of vascular endothelial cells and increasing neuronal apoptosis in the PVN of hypothalamus.

[Interaction between hypnotic agents and the hypothalamic-pituitary-adrenocorticotropic axis during surgery]

During stress, the relationship between the central nervous system and the immune system is essential to maintain homeostasis. The main neuroendocrine system involved in this interaction is the hypothalamic-pituitary-adrenal axis (HPA), which via the synthesis of glucocorticoids will modulate the intensity of the inflammatory response. Anaesthetic agents could be interacting with the HPA axis during surgery. Although etomidate currently remains in the center of the discussions, it seems, at least experimentally, that most hypnotics have the capacity to modulate the synthesis of adrenal steroids. Nevertheless, with the large literature on this subject, etomidate seems to be the most deleterious hypnotic agent on the HPA axis function. Its use should be limited when HPA axis is already altered.

Video laryngoscopy versus direct laryngoscopy for orotracheal intubation in the intensive care unit: a systematic review and meta-analysis

PURPOSE

Single studies of video laryngoscopy (VL) use for airway management in intensive care unit (ICU) patients have produced controversial findings. The aim of this study was to critically review the literature to investigate whether VL reduces difficult orotracheal intubation (OTI) rate, first-attempt success, and complications related to intubation in ICU patients, compared to standard therapy, defined as direct laryngoscopy (DL).

METHODS

We performed a systematic review and meta-analysis of randomized controlled trials, as well as prospective and retrospective observational studies, by searching PubMed, EMBASE, and bibliographies of articles retrieved. We screened for relevant studies that enrolled adults in whom the trachea was intubated in the ICU and compared VL to DL. We included studies reporting at least one clinical outcome of interest to perform a meta-analysis. We generated pooled odd ratios (OR) across studies. The primary outcome measure was difficult OTI. The secondary outcomes were first-attempt success, Cormack 3/4 grades, and complications related to intubation (severe hypoxemia, severe cardiovascular collapse, airway injury, esophageal intubation).

RESULTS

Nine trials with a total of 2,133 participants (1,067 in DL and 1,066 in VL) were included in the current analysis. Compared to DL, VL reduced the risk of difficult OTI [OR 0.29 (95% confidence interval (CI) 0.20-0.44, p < 0.001)], Cormack 3/4 grades [OR 0.26 (95% CI 0.17-0.41, p < 0.001)], and esophageal intubation [0.14 (95% CI 0.02-0.81, p = 0.03)] and increased the first-attempt success [OR 2.07 (95% CI 1.35-3.16, p < 0.001)]. No statistically significant difference was found for severe hypoxemia, severe cardiovascular collapse or airway injury.

CONCLUSIONS

These results suggest that VL could be useful in airway management of ICU patients.

Stress-dose hydrocortisone reduces critical illness-related corticosteroid insufficiency associated with severe traumatic brain injury in rats

Introduction

The spectrum of critical illness-related corticosteroid insufficiency (CIRCI) in severe traumatic brain injury (TBI) is not fully defined and no effective treatments for TBI-induced CIRCI are available to date. Despite growing interest in the use of stress-dose hydrocortisone as a potential therapy for CIRCI, there remains a paucity of data regarding its benefits following severe TBI. This study was designed to investigate the effects of stress-dose hydrocortisone on CIRCI development and neurological outcomes in a rat model of severe traumatic brain injury.

Methods

Rats were subjected to lateral fluid percussion injury of 3.2-3.5 atmosphere. These rats were then treated with either a stress-dose hydrocortisone (HC, 3 mg/kg/d for 5 days, 1.5 mg/kg on day 6, and 0.75 mg on day 7), a low-dose methylprednisolone (MP, 1 mg/kg/d for 5 days, 0.5 mg/kg on day 6, and 0.25 mg on day 7) or control saline solution intraperitoneally daily for 7 days after injury.

Results

We investigated the effects of stress-dose HC on the mortality, CIRCI occurrence, and neurological deficits using an electrical stimulation test to assess corticosteroid response and modified neurological severity score (mNSS). We also studied pathological changes in the hypothalamus, especially in the paraventricular nuclei (PVN), after stress-dose HC or a low dose of MP was administered, including apoptosis detected by a TUNEL assay, blood–brain barrier (BBB) permeability assessed by brain water content and Evans Blue extravasation into the cerebral parenchyma, and BBB integrity evaluated by CD31 and claudin-5 expression. We made the following observations. First, 70% injured rats developed CIRCI, with a peak incidence on post-injury day 7. The TBI-associated CIRCI was closely correlated with an increased mortality and delayed neurological recovery. Second, post-injury administration of stress-dose HC, but not MP or saline increased corticosteroid response, prevented CIRCI, reduced mortality, and improved neurological function during the first 14 days post injury dosing. Thirdly, these beneficial effects were closely related to improved vascular function by the preservation of tight junctions in surviving endothelial cells, and reduced neural apoptosis in the PVN of hypothalamus.

Conclusions

Our findings indicate that post-injury administration of stress-dose HC, but not MP reduces CIRCI and improves neurological recovery. These improvements are associated with reducing the damage to the tight junction of vascular endothelial cells and blocking neuronal apoptosis in the PVN of the hypothalamus.

Etomidate for intubation of patients who have sepsis or septic shock--where do we go from here?

Etomidate is an intravenous induction agent that is associated with hemodynamic stability during intubation. The agent is therefore attractive for use in critically ill patients who have a high risk of hemodynamic instability during this procedure. However, etomidate causes adrenal suppression, which itself has been associated with increased mortality in critically ill patients. The ongoing debate surrounding use of etomidate is thus centered on the immediate favorable hemodynamic profile versus the long-term risks of adrenal insufficiency, particularly in patients who have severe sepsis or septic shock.