Vasopressin-mediated adrenocorticotropin release increases plasma cortisol concentrations during cardiopulmonary resuscitation

Efficacy of combination triple therapy with vasopressin, steroid, and epinephrine in cardiac arrest: a systematic review and meta-analysis of randomized-controlled trials

Background

This study investigated whether combination therapy with vasopressin, steroid, and epinephrine (VSE) improves in-hospital survival and return of spontaneous circulation (ROSC) during and after resuscitation in-hospital cardiac arrest (CA).

Materials and methods

Various databases were explored from inception until October 2021 for relevant published clinical trials and cohort studies.

Results

Three clinical trials were included. Pooled analysis suggested that VSE was significantly associated with increased ROSC in patients with in-hospital CA (IHCA) (odds ratio (OR): 2.281, 95% confidence interval (CI): 1.304–3.989, P value = 0.004). Meta-analysis of two studies (368 patients) demonstrated a significant difference in the reduction of mean arterial pressure (MAP) during and 15–20 min after cardiopulmonary resuscitation (standardized mean difference (SMD): 1.069, 95% CI: 0.851–1.288, P value < 0.001), renal failure free days (SMD = 0.590; 95% CI: 0.312–0.869 days; P value < 0.001), and coagulation failure free days (SMD = 0.403; 95% CI: 0.128–0.679, P value = 0.004). However, no significant difference was observed for survival-to-discharge ratio (OR: 2.082, 95% CI: 0.638–6.796, P value = 0.225) and ventilator free days (SMD = 0.201, 95% CI: − 0.677, 1.079 days; P value = 0.838).

Conclusions

VSE combination therapy during and after IHCA may have beneficial effects in terms of the ROSC, renal and circulatory failure free days, and MAP.

Prospero registration: CRD42020178297 (05/07/2020).

Supplementary Information

The online version contains supplementary material available at 10.1186/s40560-022-00597-5.

A characterization of cortisol level and adrenal reservation in human cardiopulmonary arrest: systematic review and meta-analysis

BACKGROUND

Cardiopulmonary arrest (CPA) is an urgency, which is associated with high mortality. This systematic review evaluated the relationship between baseline cortisol level and the outcome of resuscitated CPA patients.

METHODS

We searched the following databases: PubMed, Scopus, ISI Web of Science, and Google Scholar. Relevant observational and controlled trials were explored from inception by April 2020. The quality of the articles was assessed using the Newcastle-Ottawa Scale (NOS).

RESULTS

Finally, five cohort studies (n = 201 participants in total) were eligible for including in the meta-analysis. The results of this meta-analysis showed that although the baseline serum cortisol levels were higher in survivors of cardiac arrest compared with non-survivors, the differences between groups do not reach a significance level (Hedges' g = 0.371, 95% CI, -0.727, 1.469, P value = 0.508). Between-study heterogeneity was statistically significant (Cochrane Q test: P value < 0.001, I2 = 89.323).

CONCLUSIONS

The result of the present meta-analysis was suggestive of a higher baseline serum cortisol levels in survivors of CPA. Future randomized controlled studies with a large sample size will determine the exact relationship between adrenal reservation and the eventual outcome of patients with CPA.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO CRD42018085468.

Clinical benefits of corticosteroid administration during adult cardiopulmonary resuscitation: A systemic review and meta-analysis

BACKGROUND

The clinical benefits of steroid administration during cardiac arrest remain unclear. Several studies reported that patients who received steroids after achieving a return of spontaneous circulation (ROSC) had better outcomes, but few studies have investigated the benefits of steroid administration during resuscitation. We hypothesized that administration of steroid during cardiac arrest would be associated with better clinical outcomes in adults with cardiac arrest.

AIM

To investigate the effect of steroid administration during cardiac arrest and the outcomes of resuscitation.

METHODS

We included studies of participants older than 18 years of age who experienced cardiac arrest and included at least one arm that received corticosteroids during cardiac arrest. A literature search of PubMed and Embase on 31 January 2021 retrieved placebo-controlled studies without limitation for type, location, and initial presenting rhythm of cardiac arrest. The study outcomes were reported by odds ratios (ORs) compared with placebo. The primary outcome was survival rate at hospital discharge. Secondary outcomes included a sustained ROSC, survival rate at hospital admission, and neurological outcome at hospital discharge.

RESULTS

Six studies including 146262 participants were selected for analysis. The risk of bias ranged from low to high for randomized-controlled trials (RCTs) and low (for non-RCTs). Steroid administration was associated with increased survival at hospital discharge [OR: 3.51, 95% confidence interval (CI): 1.98-6.20, P < 0.001], and steroid administration during cardiac arrest was associated with both an increased rate of sustained ROSC (OR: 1.81, 95%CI: 1.91-4.02, P < 0.001) and a favorable neurological outcome at hospital discharge (OR: 3.02, 95%CI: 1.26-7.24, P = 0.01).

CONCLUSION

Steroid administration during cardiac arrest was associated with better outcomes of resuscitation. Further study of the use of steroid in the selected circumstances are warranted.

Efficacy of Glucocorticoid Administration in Patients with Cardiac Arrest: A Systematic Review of Clinical Studies

BACKGROUND

The pathophysiology of cardiac arrest (CA) involves over-activation of systemic inflammatory responses, relative adrenal insufficiency, and glycocalyx damage. Corticosteroids have beneficial effects in preventing the perturbation of the endothelial glycocalyx.

OBJECTIVES

The aim of this systematic review was to determine the efficacy of glucocorticoids in patients with cardiac arrest.

METHODS

We searched PubMed, Scopus, ISI Web of Science, Google Scholar and Cochrane central register for relevant clinical trials and cohort studies until September 2019.

RESULTS

We retrieved 7 peer-reviewed published studies for the systematic review. Two studies were clinical trials evaluating 147 patients, while five illustrated cohort design, evaluating 196,192 patients. In total, 196,339 patients were assessed. There was limited evidence and conflicting results to establish a correlation between glucocorticoids and the survival of patients suffering from cardiac arrest. However, the link between these medications and survival-to-admission, survival-to discharge, and 1-year survival rates was strong and consistent in observational studies.

CONCLUSION

The clinical evidence regarding the efficacy and safety of glucocorticoids in CA is limited to observational studies with inconsistent methodology and few clinical trials with small sample size. Nevertheless, it seems that glucocorticoid supplementation during and after cardiopulmonary resuscitation (CPR) may have significant effects in terms of survival-to-admission, survival to discharge, 1-year survival rates and an improved return of spontaneous circulation (ROSC) rate, especially in patients with hemodynamic instability and cardiovascular diseases (i.e., refractory hemodynamic shock). Future studies with high-quality, large-scale, long-term intervention and precise baseline characteristics are needed to evaluate the exact effective dose, duration, and efficacy of glucocorticoids in CA.

Steroid use after cardiac arrest is associated with favourable outcomes: a systematic review and meta-analysis

Background

The effect of steroid use on outcomes in patients with cardiac arrest (CA) remains controversial. We systematically reviewed the literature to investigate whether steroid use after CA increased the return of spontaneous circulation (ROSC) rate and survival to discharge in patients with CA.

Methods

PubMed, Embase, CNKI, and the Cochrane Central Register of Controlled Trials were searched for randomized controlled trials (RCTs) and observational studies on the effect of steroid use on outcomes in adults with CA. The outcomes were ROSC and survival to discharge.

Results

Seven studies (four RCTs and three observational studies) were included. Pooled analysis suggested that steroid use was associated with increased ROSC in patients with CA. Steroid use was significantly associated with survival to discharge, which was a consistent finding in RCTs and observational studies. Subgroup analysis based on the time of drug administration (during cardiopulmonary resuscitation [CPR] vs. after CA) showed that steroid use during CPR and after CA were significantly associated with an increased rate of ROSC and survival to discharge.

Conclusion

Current evidence indicates that steroid use after CA could increase ROSC and survival to discharge in patients with CA. However, high-quality and adequately powered RCTs are warranted.

Efficacy and safety of corticosteroid therapy in patients with cardiac arrest: a systematic review of randomised controlled trials

PURPOSES

The role of corticosteroid therapy in patients with cardiac arrest (CA) is uncertain. We aimed to evaluate the efficacy and safety of corticosteroid therapy in CA patients.

METHODS

Randomised controlled trials were identified using PubMed, EMBASE, Cochrane Central Register of Controlled Trials, the Chinese National Knowledge Infrastructure and the Chinese Biomedical Literature Database. The primary outcome was overall survival. Secondary outcomes were positive neurological status and probability of sustained restoration of spontaneous circulation (ROSC). Complications were infection and bleeding. Given the significant heterogeneity across previous studies, combining the data using meta-analysis was deemed not appropriate.

RESULTS

Five studies (551 patients) met the criteria. Two studies of co-intervention therapy (corticosteroid, vasopressin and epinephrine protocol) found that this approach could benefit in-hospital CA patient survival rates at hospital discharge, improve neurological function at hospital discharge and yield sustained ROSC rate. However, further two studies failed to demonstrate that corticosteroid therapy alone could improve survival and neurological outcomes among CA patients. Additionally, corticosteroid therapy did not increase the risk of infection and bleeding.

CONCLUSIONS

Due to the inherent limitations of the studies in this review, we have not been able to reach definitive conclusions. Larger-scale and better-designed studies are therefore recommended, to further evaluate the potential and rational use of corticosteroid therapy in CA patients.

Current Challenges in Neonatal Resuscitation: What is the Role of Adrenaline?

Adrenaline, also known as epinephrine, is a hormone, neurotransmitter, and medication. It is the best established drug in neonatal resuscitation, but only weak evidence supports current recommendations for its use. Furthermore, the available evidence is partly based on extrapolations from adult studies, and this introduces further uncertainty, especially when considering the unique physiological characteristics of newly born infants. The timing, dose, and route of administration of adrenaline are still debated, even though this medication has been used in neonatal resuscitation for a long time. According to the most recent Neonatal Resuscitation Guidelines from the American Heart Association, adrenaline use is indicated when the heart rate remains < 60 beats per minute despite the establishment of adequate ventilation with 100% oxygen and chest compressions. The aforementioned guidelines recommend intravenous administration (via an umbilical venous catheter) of adrenaline at a dose of 0.01-0.03 mg/kg (1:10,000 concentration). Endotracheal administration of a higher dose (0.05-0.1 mg/kg) may be considered while venous access is being obtained, even if supportive data for endotracheal adrenaline are lacking. The safety and efficacy of intraosseous administration of adrenaline remain to be investigated. This article reviews the evidence on the circulatory effects and tolerability of adrenaline in the newborn, discusses literature data on adrenaline use in neonatal cardiopulmonary resuscitation, and describes international recommendations and outcome data regarding the use of this medication during neonatal resuscitation.

Glucocorticoid use during cardiopulmonary resuscitation may be beneficial for cardiac arrest

BACKGROUND

Various studies have indicated that glucocorticoid supplementation during cardiopulmonary resuscitation (CPR), in conjunction with vasopressors, may improve outcomes in instances of cardiac arrest. However, further population-based analysis is warranted with respect to resuscitative and long-term survival benefits conferred by administering glucocorticoids in this setting.

METHODS

A total of 145,644 adult patients who experienced non-traumatic, cardiac arrest occurred at emergency room during years 2004-2011 were selected for study from the Taiwan National Health Insurance Research database. These patients were grouped as steroid and non-steroid recipients during CPR, and group members were matched in terms of patient characteristics, including presenting complaint, prior steroid use, resuscitative drugs and shocks delivered, treatment setting (medical center or not), socioeconomic status, and year that cardiac arrest occurred, through propensity scoring. Logistic regression analysis was performed to determine the impact of steroid usage on survival to admission, survival to discharge, and 1-year survival.

RESULTS

Compared with matched non-steroid group members (n=8628), patients given steroid (n=2876) displayed significantly higher rates of survival to admission (38.32% vs 18.67%; adjusted OR=2.97, 95% CI 2.69-3.29; p<0.0001), survival to discharge (14.50% vs 5.61%; adjusted OR=1.71, 95% CI 1.42-2.05; p<0.0001), and 1-year overall survival (10.81% vs 4.74%; adjusted OR=1.48, 95% CI 1.22-1.79; p<0.0001). Steroid use proved more beneficial in patients with COPD or asthma and in the absence of shockable rhythm during CPR.

CONCLUSION

Glucocorticoid use during CPR is associated with improved survival-to-admission, survival-to-discharge, and 1-year survival rates.

Glucocorticoids as an emerging pharmacologic agent for cardiopulmonary resuscitation

Although cardiac arrest (CA) constitutes a major health problem with dismal prognosis, no specific drug therapy has been shown to improve survival to hospital discharge. CA causes adrenal insufficiency which is associated with poor outcome and increased mortality. Adrenal insufficiency may manifest as an inability to increase cortisol secretion during and after cardiopulmonary resuscitation (CPR). Several studies suggest that glucocorticoids during and after CPR seem to confer benefits with respect to return of spontaneous circulation (ROSC) rates and long term survival. They have beneficial hemodynamic effects that may favor their use during CPR and in the early post-resuscitation period. Moreover, they have anti-inflammatory and anti-apoptotic properties that improve organ function by reducing ischemia/reperfusion (I/R) injury. However, glucocorticoid supplementation has shown conflicting results with regard to survival to hospital discharge and neurological outcome. The purpose of this article is to review the pathophysiology of hypothalamic-pituitary-adrenal (HPA) axis during CPR. Furthermore, this article reviews the effects of glucocorticoids use during CRP and the post-resuscitation phase.

Medications in neonatal resuscitation: epinephrine and the search for better alternative strategies

Epinephrine remains the primary vasopressor for neonatal resuscitation complicated by asystole or prolonged bradycardia not responsive to adequate ventilation and chest compressions. Epinephrine increases coronary perfusion pressure primarily through peripheral vasoconstriction. Current guidelines recommend intravenous epinephrine administration (0.01-0.03 mg/kg). Endotracheal epinephrine administration results in unpredictable absorption. High-dose intravenous epinephrine poses additional risks and does not result in better long-term survival. Vasopressin has been considered an alternative to epinephrine in adults, but there is insufficient evidence to recommend its use in newborn infants. Future research will focus on the best sequence for epinephrine administration and chest compressions.

Adrenal gland blood flow and noradrenaline plasma concentration during CPR in pigs

AIM OF THE STUDY

In comparison to adrenaline, administration of vasopressin increases adrenal gland perfusion, but decreases catecholamine plasma concentrations when compared to saline placebo. We directly compared the effects of adrenaline with different doses of vasopressin on adrenal gland perfusion, and noradrenaline plasma concentrations during CPR.

METHODS

Twenty-one pigs received either 0.2 mg kg(-1) adrenaline (n = 7), 0.2 U kg(-1) vasopressin (n = 7), or 0.8 U kg(-1) vasopressin (n = 7) after 4 min of cardiac arrest and 3 min of CPR. Adrenal gland perfusion was determined using radiolabeled microspheres, noradrenaline plasma concentration was measured by high pressure liquid chromatography.

RESULTS

Before administration of vasopressor drugs during CPR, adrenal gland perfusion, and noradrenaline plasma concentrations were not different between groups. Ninety seconds and 5 min after drug administration, adrenal gland perfusion was significantly higher with both doses of vasopressin when compared with adrenaline, but was not different between the vasopressin groups. Noradrenaline plasma concentrations were 23684 ± 5036 pg ml(-1) with adrenaline, 11455 ± 2450 pg ml(-1) with 0.2 U kg(-1) vasopressin, and 12119 ± 2921 pg ml(-1) with 0.8 U kg(-1) vasopressin at 90 s after administration of vasopressors (p < .05 for both doses of vasopressin vs adrenaline). Five of seven animals in the adrenaline group, five of seven animals in the 0.2 U kg(-1) vasopressin group, and six of seven animals in the 0.8 U kg(-1) vasopressin group were successfully defibrillated.

CONCLUSIONS

Vasopressin enhances adrenal gland perfusion, but decreases noradrenaline plasma concentration when compared to adrenaline during CPR. Neither adrenal gland perfusion nor noradrenaline plasma concentration affect survival in this pig model of cardiac arrest.

The effect of hydrocortisone on the outcome of out-of-hospital cardiac arrest patients: a pilot study

OBJECTIVE

Several studies have disclosed the importance of serum adrenocorticotropic hormone and cortisol levels in resuscitation. The objective of this study was to observe the effect of hydrocortisone on the outcome of out-of-hospital cardiac arrest (OHCA) patients.

DESIGN

Prospective, nonrandomized, open-labeled clinical trial.

SETTING

Emergency department (ED) of National Taiwan University Hospital.

PATIENTS AND PARTICIPANTS

Ninety-seven nontraumatic adult OHCA victims.

INTERVENTIONS

Serum adrenocorticotropic hormone and total cortisol levels were examined in all patients. The hydrocortisone group (n = 36) received 100 mg intravenous hydrocortisone during resuscitation, and the nonhydrocortisone group (n = 61) received 0.9% saline as placebo.

MEASUREMENTS AND RESULTS

Comparison of return of the spontaneous circulation (ROSC) rates between the 2 groups was analyzed. The hydrocortisone group had a significantly higher ROSC rate than the nonhydrocortisone group (61% vs 39%, P = .038). Hydrocortisone administration within 6 minutes after ED arrival led to an increased ROSC rate (90% vs 50%, P = .045). The hydrocortisone and nonhydrocortisone groups did not differ in the development of electrolyte disturbances, gastrointestinal tract bleeding, or infection during early postresuscitation period (gastrointestinal bleeding: 41% vs 46%, P = .89; infection: 50% vs 75%, P = .335). There was no significant difference between the hydrocortisone and nonhydrocortisone groups in terms of 1- and 7-day survival and hospital discharge rates.

CONCLUSIONS

Hydrocortisone treatment during resuscitation, particularly when administrated within 6 minutes of ED arrival, may be associated with an improved ROSC rate in OHCA patients.

Drug administration in animal studies of cardiac arrest does not reflect human clinical experience

INTRODUCTION

To date, there is no evidence showing a benefit from any advanced cardiac life support (ACLS) medication in out-of-hospital cardiac arrest (OOHCA), despite animal data to the contrary. One explanation may be a difference in the time to first drug administration. Our previous work has shown the mean time to first drug administration in clinical trials is 19.4min. We hypothesized that the average time to drug administration in large animal experiments occurs earlier than in OOHCA clinical trials.

METHODS

We conducted a literature review between 1990 and 2006 in MEDLINE using the following MeSH headings: swine, dogs, resuscitation, heart arrest, EMS, EMT, ambulance, ventricular fibrillation, drug therapy, epinephrine, vasopressin, amiodarone, lidocaine, magnesium, and sodium bicarbonate. We reviewed the abstracts of 331 studies and 197 full manuscripts. Exclusion criteria included: non-peer reviewed, all without primary animal data, and traumatic models. From these, we identified 119 papers that contained unique information on time to medication administration. The data are reported as mean, ranges, and 95% confidence intervals. Mean time to first drug administration in animal laboratory studies and clinical trials was compared with a t-test. Regression analysis was performed to determine if time to drug predicted ROSC.

RESULTS

Mean time to first drug administration in 2378 animals was 9.5min (range 3.0-28.0; 95% CI around mean 2.78, 16.22). This is less than the time reported in clinical trials (19.4min, p<0.001). Time to drug predicted ROSC (odds ratio 0.844; 95% CI 0.738, 0.966).

CONCLUSION

Shorter drug delivery time in animal models of cardiac arrest may be one reason for the failure of animal studies to translate successfully into the clinical arena.

[Utility of vasopressin in cardiopulmonary resuscitation]

Many vasopressants have been studied in cardiopulmonary resuscitation (CPR) to increase cerebral and coronary perfusion. Although there is a debate on the utility of epinephrine, this is the one that has been used historically, above all after verifying that other agents such as norepinephrine, metoxamine or phenylephrine, have not been shown to be more effective. Currently, due to the good experimental results, the use of vasopressin (ADH) in CPR is being evaluated. However there is little (only three studies) and debated evidence based on randomized clinical trials (norepinephrine or ADH) in humans. Once these are reviewed, it can be concluded: The results of the three randomized studies in humans obtain different results regarding the utility of ADH in cardiorespiratory arrest (CRA) secondary to ventricular fibrillation, electro-mechanical dissociation or asystole. More prospective studies are needed to know the role of ADH in prolonged CRA and in asystole, that may be the subgroups that can benefit the most from this drug. The neurological repercussion of a drug in the context of CRA should be evaluated before its inclusion in the CPR guides.

Evolving role of vasopressin in the treatment of cardiac arrest

Sudden cardiac arrest is a major public heath problem, affecting more than 450,000 individuals annually. Response time and the initiation of cardiopulmonary resuscitation (CPR) remain the most important factors determining successful revival. During resuscitation, sympathomimetics are given to enhance cerebral and coronary perfusion pressures in an attempt to achieve restoration of spontaneous circulation. Epinephrine has been the preferred vasopressor since the inception of advanced cardiac life support, although the lack of definitive evidence regarding its effectiveness has created much controversy surrounding its use, including the optimum dosage. Vasopressin is an alternative vasopressor that, when given at high doses, causes vasoconstriction by directly stimulating smooth muscle V1 receptors. The 2000 American Heart Association (AHA) guidelines commented that vasopressin is a reasonable first-line vasopressor in patients with ventricular fibrillation or pulseless ventricular tachycardia. Since release of those guidelines, additional human studies support an expanded role for vasopressin, whereas other studies cast doubt regarding its efficacy compared with epinephrine. The AHA recently released revised guidelines for CPR and emergency cardiovascular care. The consensus was that vasopressors should remain a part of pulseless sudden cardiac arrest management, with epinephrine 1 mg every 3-5 minutes being the recommended adrenergic of choice. In these revised guidelines, the role of vasopressin expanded beyond previous recommendations, despite the recommendation being downgraded to class indeterminate. The guidelines comment that one dose of vasopressin 40 U may replace the first or second dose of epinephrine in all pulseless sudden cardiac arrest scenarios, including asystole and pulseless electrical activity. A consistent theme with all vasopressors in sudden cardiac arrest is that additional studies are necessary to clearly document greater efficacy compared with no treatment. Further evaluation is warranted to better assess the role of vasopressin in asystolic sudden cardiac arrest, as well as its use with epinephrine, and to determine its optimal timing of administration and potential synergistic effects.

Vasopressin during cardiopulmonary resuscitation and different shock states: a review of the literature

Vasopressin administration may be a promising therapy in the management of various shock states. In laboratory models of cardiac arrest, vasopressin improved vital organ blood flow, cerebral oxygen delivery, the rate of return of spontaneous circulation, and neurological recovery compared with epinephrine (adrenaline). In a study of 1219 adult patients with cardiac arrest, the effects of vasopressin were similar to those of epinephrine in the management of ventricular fibrillation and pulseless electrical activity; however, vasopressin was superior to epinephrine in patients with asystole. Furthermore, vasopressin followed by epinephrine resulted in significantly higher rates of survival to hospital admission and hospital discharge. The current cardiopulmonary resuscitation guidelines recommend intravenous vasopressin 40 IU or epinephrine 1mg in adult patients refractory to electrical countershock. Several investigations have demonstrated that vasopressin can successfully stabilize hemodynamic variables in advanced vasodilatory shock. Use of vasopressin in vasodilatory shock should be guided by strict hemodynamic indications, such as hypotension despite norepinephrine (noradrenaline) dosages >0.5 mug/kg/min. Vasopressin must never be used as the sole vasopressor agent. In our institutional routine, a fixed vasopressin dosage of 0.067 IU/min (i.e. 100 IU/50 mL at 2 mL/h) is administered and mean arterial pressure is regulated by adjusting norepinephrine infusion. When norepinephrine dosages decrease to 0.2 microg/kg/min, vasopressin is withdrawn in small steps according to the response in mean arterial pressure. Vasopressin also improved short- and long-term survival in various porcine models of uncontrolled hemorrhagic shock. In the clinical setting, we observed positive effects of vasopressin in some patients with life-threatening hemorrhagic shock, which had no longer responded to adrenergic catecholamines and fluid resuscitation. Clinical employment of vasopressin during hemorrhagic shock is experimental at this point in time.

Critical Care Providers’ Perceptions of the Use of Vasopressin in Cardiac Arrest

• Background Although published algorithms and guidelines list epinephrine and vasopressin as either/or choices for treatment of ventricular fibrillation and/or pulseless ventricular tachycardia, little is known about how critical care providers respond to this recommendation.

• Objectives To assess the use of vasopressin as a first-line drug of choice for ventricular fibrillation and/or pulseless ventricular tachycardia and describe factors that may influence decision making for using vasopressin.

• Methods A convenience sample from 4 academic medical centers in the United States was recruited to complete a 20-item survey on demographic factors such as year of last Advanced Cardiac Life Support (ACLS) provider course, specialty certification, predominant practice responsibility, and beliefs related to the use of vasopressin for cardiac arrest. Descriptive statistics, Pearson correlation analysis, and logistic regression were used to analyze the data.

• Results A total of 214 critical care providers (80% registered nurses) completed the survey. Year of last ACLS course (r = −0.188, P = .006) was a significant demographic factor, and behavioral beliefs (attitude about using vasopressin) had the strongest relationship (r = 0.687, P &lt; .001) and were the best predictor for intentions to use or recommend the use of vasopressin (beta=0.589, P&lt;.001).

• Conclusions Despite the recommendation for vasopressin as an agent equivalent to epinephrine for treatment of ventricular fibrillation and/or pulseless ventricular tachycardia, 63% of respondents used epinephrine as a first-line drug of choice. More research is needed to address the classification system for interpreting the quality of evidence that may influence practice.

Prognostic value of relative adrenal insufficiency after out-of-hospital cardiac arrest

OBJECTIVE

To assess the prevalence of relative adrenal insufficiency in patients successfully resuscitated after cardiac arrest, and its prognostic role in post-resuscitation disease.

DESIGN AND SETTING

A prospective observational single-center study in a medical intensive care unit.

PATIENTS

64 patients hospitalised in the intensive care unit after successful resuscitation for out-of-hospital cardiac arrest.

MEASUREMENTS AND RESULTS

A corticotropin-stimulation test was performed between 12 and 24 h following admission: serum cortisol level was measured before and 60 min after administration of tetracosactide 250 microg. Patients with an incremental response less than 9 microg/dl were considered to have relative adrenal insufficiency (non-responders). Variables were expressed as medians and interquartile ranges. 33 patients (52%) had relative adrenal insufficiency. Baseline cortisol level was higher in non-responders than in responders (41 [27.2-55.5] vs. 22.8 [15.7-35.1] microg/dl respectively, P=0.001). A long interval before initiation of cardiopulmonary resuscitation was associated with relative adrenal insufficiency (5 [3-10] vs. 3 [3-5] min, P=0.03). Of the 38 patients with post-resuscitation shock, 13 died of irreversible multiorgan failure. The presence of relative adrenal insufficiency was identified as a poor prognostic factor of shock-related mortality (log-rank P=0.02). A trend towards higher mortality in non-responders was identified in a multivariate logistic regression analysis (odds ratio 6.77, CI 95% 0.94-48.99, P=0.058).

CONCLUSIONS

Relative adrenal insufficiency occurs frequently after successful resuscitation of out-of-hospital cardiac arrest, and appears to be associated with a poor prognosis in cases of post-resuscitation shock. The role of corticosteroid supplementation should be evaluated in this setting.

Serum cortisol as a predictive marker of the outcome in patients resuscitated after cardiopulmonary arrest

OBJECTS

To analyze the relationship between stress hormones (arginine vasopressin (ADH), adrenocorticotropic hormone (ACTH) and cortisol and the outcome of patients resuscitated after cardiopulmonary arrest (CPA).

METHODS

Thirty-six patients were enrolled in this study. In 36 of the resuscitated cases, 27 were non-survivors and 9 survived. The survival group was defined as cases either in a persistent vegetative state, with some disability or good recovery 1 month after return of spontaneous circulation (ROSC). The non-survival group was defined as cases who died within 1 month.

RESULTS

The plasma ADH and ACTH levels and the serum cortisol levels in both the surviving and the non-surviving patients were 82.3+/-74.5 and 149.6+/-135.4 (pg/ml), 239.7+/-327.4 and 282.4+/-553.0 (pg/ml), 34.1+/-11.2 and 19.0+/-12.8 (g/ml) (mean+/-S.D., respectively). The plasma ADH and ACTH levels showed no significant difference between the two groups. The serum cortisol levels were significantly higher in survivors than in the non-survivors (P=0.029). We also used the receiving-operating characteristics (ROC) curves to evaluate the optimal cutoff value of the concentration of serum cortisol as a predictive maker of non-surviving patients. The cutoff value of 16.7 g/ml for the concentrations of serum cortisol was a 1.00 positive predictive value and a 1.00 specificity at a 0.519 negative predictive and a 0.409 sensitivity for predicting non-surviving patients. The area under the ROC curve was calculated to be 0.858 at a prevalence of 0.58. The plasma ADH levels correlated significantly and positively with the plasma ACTH levels (r=0.516, P<0.0010).

CONCLUSIONS

We concluded that the serum cortisol levels were significantly higher in survivors than in non-survivors resuscitated after CPA.

Is vasopressin superior to adrenaline or placebo in the management of cardiac arrest? A meta-analysis

Vasopressin is currently recommended in the management of patients with cardiac arrest, but its efficacy is still incompletely established. We systematically reviewed randomized trials comparing vasopressin to control treatment in the management of cardiac arrest in humans and animals. Two human and 33 animal studies were retrieved. At pooled analysis vasopressin appeared equivalent to adrenaline (epinephrine) in the management of human cardiac arrest (N=240), with, respectively 63 (78/124) vs 59% (68/116) ROSC (P=0.43), and 16 (20/124) vs 14% (16/116) survival to hospital discharge (P=0.52). In animal trials (N=669) vasopressin appeared instead significantly superior to both placebo (ROSC, respectively 93 [98/105] vs 19% [14/72], P<0.001) or adrenaline (ROSC, respectively 84 [225/268] vs 52% [117/224], P<0.001). In conclusion, vasopressin is superior to both placebo or adrenaline in animal models of cardiopulmonary resuscitation. Evidence in humans is still limited and confidence intervals estimates too wide to reliably confirm or disprove results obtained in experimental animal settings.

Management of vasodilatory shock: defining the role of arginine vasopressin

The rationale for an arginine vasopressin (argipressin) infusion was put forward after it was discovered that patients in shock states might have an endogenous arginine vasopressin deficiency. Subsequently, several investigations impressively demonstrated that arginine vasopressin can successfully stabilise haemodynamics even in advanced vasodilatory shock. We report on physiological and pharmacological aspects of arginine vasopressin, and summarise current clinical knowledge on employing a continuous arginine vasopressin infusion in critically ill patients with catecholamine-resistant vasodilatory shock of different aetiologies. In view of presented experimental evidence and current clinical experience, a continuous arginine vasopressin infusion of approximately 2 to approximately 6 IU/h can be considered as a supplemental strategy to vasopressor catecholamines in order to preserve cardiocirculatory homeostasis in patients with advanced vasodilatory shock. Because data on adverse effects are still limited, arginine vasopressin should be reserved for patients in whom adequate haemodynamic stabilisation cannot be achieved with conventional vasopressor therapy or who have obvious adverse effects of catecholamines that result in further significant haemodynamic deterioration. For the same reasons, arginine vasopressin should not be used as a single, alternative vasopressor agent instead of catecholamine vasopressors. Future prospective studies will be necessary to define the exact role of arginine vasopressin in the therapy of vasodilatory shock.

Effects of vasopressin on right ventricular function in an experimental model of acute pulmonary hypertension

OBJECTIVE

Arginine vasopressin is a promising systemic vasopressor in settings such as vasodilatory shock and cardiopulmonary resuscitation. The evidence that arginine vasopressin may also have a pulmonary vasodilatory effect makes it an attractive drug for the treatment of circulatory shock secondary to right ventricular failure and pulmonary hypertension. In the present study, we evaluated the effects of arginine vasopressin on right ventricular function and ventriculovascular coupling in the setting of moderate acute pulmonary hypertension and compared these effects with those of phenylephrine.

DESIGN

Prospective laboratory investigation using an established model of acute pulmonary hypertension.

SETTING

University hospital laboratory.

SUBJECTS

Seven adult beagle dogs weighing 8-14 kg.

INTERVENTIONS

After acute instrumentation to measure right ventricular pressure and volume with the conductance technique and pulmonary artery flow and pressure with high-fidelity transducers, the stable thromboxane analogue U46619 was infused continuously to obtain stable pulmonary hypertension. Phenylephrine and arginine vasopressin were administered consecutively in continuous infusions at doses titrated to achieve a 25% increase in aortic pressure.

MEASUREMENTS AND MAIN RESULTS

Phenylephrine and arginine vasopressin both increased total pulmonary vascular resistance and arterial elastance without influencing characteristic impedance. Both drugs decreased cardiac output and stroke volume. Right ventricular hydraulic power output was reduced by arginine vasopressin but not by phenylephrine. Most importantly, arginine vasopressin caused a 31% decrease in right ventricular contractility measured as the slope of the preload recruitable stroke work relationship, whereas contractility was preserved during phenylephrine infusion.

CONCLUSIONS

In the present model, arginine vasopressin causes pulmonary vascular constriction and exerts an important negative inotropic effect on the right ventricle. These findings suggest that one should be cautious in the use of arginine vasopressin when right ventricular function is compromised.

Vasopressin: new uses in critical care

The science of medicine has evolved dramatically over recent years, with better understanding of the mechanisms of disease leading to innovative new treatments. However, the critical care patient still suffers from a high mortality rate with few advances from the traditional modalities of therapy. Arginine vasopressin has been explored as a vasoconstrictor in the treatment of the hypotension associated with septic shock. This drug has also recently been added to the advanced cardiac life support protocol for the resuscitation of pulseless ventricular tachycardia and ventricular fibrillation. Studies of arginine vasopressin in these situations have been promising but still have yet to prove a survival benefit over traditional therapies. Newer and larger trials are necessary to determine whether any mortality benefit can be sustained from the use of arginine vasopressin in critical care patients with septic shock and cardiac arrest secondary to pulseless ventricular tachycardia and ventricular fibrillation.

Resuscitation from cardiac arrest with adrenaline/epinephrine or vasopressin: effects on intestinal mucosal tonometer pCO(2) during the postresuscitation period in rats

BACKGROUND

The use of vasopressin instead of adrenaline/epinephrine during resuscitation improves vital organ perfusion, but the effects on mesenteric perfusion following successful resuscitation are not fully evaluated. The present study was designed to compare the effects of vasopressin and adrenaline/epinephrine, given to rats during resuscitation from ventricular fibrillation, on to mesenteric ischaemia, as determined by intestinal mucosal tonometer pCO(2) during the postresuscitation period.

METHODS AND RESULTS

Male Sprague-Dawley rats (n=28) were allocated randomly to receive vasopressin (0.8 U/kg) or adrenaline/epinephrine (90 microg/kg) after 5 min of ventricular fibrillation. Precordial chest compression was initiated 4 min after the start of ventricular fibrillation, continued for 4 min, and followed by defibrillation. Seven of 14 (vasopressin) and 12 of 14 (adrenaline/epinephrine) rats were successfully defibrillated (P=0.10, Fisher's exact test) and observed for 60 min. Intestinal mucosal tonometer pCO(2) measurements before cardiac arrest and 15, 30, and 60 min following return of spontaneous circulation were 47+/-3, 73+/-8, 63+/-7, and 56+/-6 mmHg in the vasopressin group and 48+/-5, 78+/-7, 67+/-6, and 62+/-6 mmHg in the adrenaline/epinephrine group (P<0.05 at 60 min between vasopressin and adrenaline/epinephrine). Right atrial hemoglobin oxygen saturations at these time points were 73+/-5, 51+/-12, 58+/-11, and 63+/-5% in the vasopressin group and 76+/-7, 44+/-10, 52+/-10 and 54+/-8% in the adrenaline/epinephrine group (P<0.05 at 60 min between vasopressin and adrenaline/epinephrine).

CONCLUSIONS

We conclude that in this rat model the administration of vasopressin instead of adrenaline/epinephrine for CPR tends to be associated with lower resuscitation success, but less mesenteric ischaemia during the postresuscitation period in successfully resuscitated rats.

Vasopressin versus epinephrine for inhospital cardiac arrest: a randomised controlled trial

BACKGROUND

Survival rates for cardiac arrest patients, both in and out of hospital, are poor. Results of a previous study suggest better outcomes for patients treated with vasopressin than for those given epinephrine, in the out-of-hospital setting. Our aim was to compare the effectiveness and safety of these drugs for the treatment of in-patient cardiac arrest.

METHODS

We did a triple-blind randomised trial in the emergency departments, critical care units, and wards of three Canadian teaching hospitals. We assigned adults who had cardiac arrest and required drug therapy to receive one dose of vasopressin 40 U or epinephrine 1 mg intravenously, as the initial vasopressor. Patients who failed to respond to the study intervention were given epinephrine as a rescue medication. The primary outcomes were survival to hospital discharge, survival to 1 h, and neurological function. Preplanned subgroup assessments included patients with myocardial ischaemia or infarction, initial cardiac rhythm, and age.

FINDINGS

We assigned 104 patients to vasopressin and 96 to epinephrine. For patients receiving vasopressin or epinephrine survival did not differ for hospital discharge (12 [12%] vs 13 [14%], respectively; p50.67; 95% CI for absolute increase in survival 211.8% to 7.8%) or for 1 h survival (40 [39%] vs 34 [35%]; p50.66; 210.9% to 17.0%); survivors had closely similar median mini-mental state examination scores (36 [range 19-38] vs 35 [20-40]; p50.75) and median cerebral performance category scores (1 vs 1).

INTERPRETATION

We failed to detect any survival advantage for vasopressin over epinephrine. We cannot recommend the routine use of vasopressin for inhospital cardiac arrest patients, and disagree with American Heart Association guidelines, which recommend vasopressin as alternative therapy for cardiac arrest.