The use of undiluted amiodarone in the management of out-of-hospital cardiac arrest

Amiodarone Administration during Cardiopulmonary Resuscitation Is Not Associated with Changes in Short-Term Mortality or Neurological Outcomes in Cardiac Arrest Patients with Shockable Rhythms

Background: The search for the best therapeutic approach in cardiopulmonary resuscitations (CPR) remains open to question. In this study, we evaluated if Amiodarone administration during CPR was associated with short-term mortality or neurological development. Methods: A total of 232 patients with sudden cardiac arrest (CA) with shockable rhythms were included in our analysis. Propensity score matching based on age, gender, type of CA, and CPR duration was used to stratify between patients with and without Amiodarone during CPR. Primary endpoints were short-term mortality (30-day) and neurological outcomes assessed by the cerebral performance category. Secondary endpoints were plasma lactate, phosphate levels at hospital admission, and the peak Neuron-specific enolase. Results: Propensity score matching was successful with a caliper size used for matching of 0.089 and a sample size of n = 82 per group. The 30-day mortality rates were similar between both groups (p = 0.24). There were no significant differences in lactate levels at hospital admission and during the following five days between the groups. Patients receiving Amiodarone showed slightly higher phosphate levels at hospital admission, while the levels decreased to a similar value during the following days. Among CA survivors to hospital discharge, no differences between the proportion of good neurological outcomes were detected between the two groups (p = 0.58), despite slightly higher peak neuron-specific enolase levels in CA patients receiving Amiodarone (p = 0.03). Conclusions: Amiodarone administration is not associated with short-term mortality or neurological outcomes in CA patients with shockable rhythms receiving CPR.

Comparison the efficacy of amiodarone and lidocaine for cardiac arrest: A network meta-analysis

BACKGROUND

There is no evidence that antiarrhythmic drugs can improve long-term survival or survival with favorable neurological outcomes in cardiac arrest patients. We did this network meta-analysis to comprehensively compare the efficacy of various antiarrhythmic drugs for cardiac arrest patients.

METHODS

We searched studies from inception until Nov 11, 2022 through PubMed, Embase, Cochrane Library, China National Knowledge Infrastructure (CNKI), VIP Database, and Wanfang database. All studies comparing different antiarrhythmic drugs for cardiac arrest were included in this meta-analysis. Outcomes were survival to hospital discharge in cardiac arrest, survival to hospital admission/24 h and favorable neurological outcome. This network meta-analysis was performed by R software.

RESULTS

Finally, a total of 9 studies (10,980 patients) were finally included in this network meta-analysis. Amiodarone (odd ratio [OR] 2.28, 95% credibility interval [CrI] 1.61-3.27) and lidocaine (OR 1.53, 95% CrI 1.05-2.25) was superior than placebo in terms of the survival to hospital admission/24 h with statistically significant. Amiodarone (OR 2.19, 95% CrI 1.54-3.14) and lidocaine (OR 1.58, 95% CrI 1.09-2.32) was superior than placebo in terms of the survival to hospital discharge with statistically significant. Amiodarone (OR 2.43, 95% CrI 1.61-3.68) and lidocaine (OR 1.62, 95% CrI 1.04-2.53) was superior than placebo in terms of the favorable neurological outcome with statistically significant. The surface under the cumulative ranking (SUCRA) shows that amiodarone ranked first (SUCRA, 99.6%), lidocaine ranked second (SUCRA, 49.6%), placebo ranked the last (SUCRA, 0.86%). Inverted funnel plot is essentially symmetrical, it is possible that this study has a small sample effect or a small publication bias.

CONCLUSIONS

Amiodarone had the best effect on both survival to hospital admission, discharge and more favorable neurological outcome. Thus, amiodarone should be listed as first line drug for cardiac arrest. However, the quality of available evidence limits the formation of powerful conclusions regarding the comparative efficacy or safety of amiodarone or lidocaine used to treat cardiac arrest. Higher-quality randomized controlled trials are required for further research in future.

Pharmacokinetic Disposition of Amiodarone When Given with an Intralipid Rescue Strategy

While the antiarrhythmic drug amiodarone is commonly used in clinical practice, it has a narrow therapeutic index that can lead to acute overdose. One proposed method to deal with this toxicity is lipid emulsion therapy, which may potentially quench the free amiodarone in blood and prevent its further distribution to target organs and tissues. In this study, we utilize an established swine model to examine the effects of Intralipid™ (IL) administration for acute amiodarone toxicity. A total of 14 pigs received an overdose of intravenous amiodarone. After twenty minutes, half of the pigs (n = 7) received IL while the control group (n = 7) received normal saline. Serum concentrations of amiodarone were then analyzed using a validated high-performance liquid chromatography (HPLC) method. Noncompartmental pharmacokinetic analyses were performed on the observed concentrations. There were no statistical differences in the area under the concentration time curve (6 h) or clearance, but there was a difference in the half-life between the two groups (3.12 vs. 0.85 h, p = 0.01). The administration of IL did not statistically change the overall exposure of amiodarone in the blood in the first 6 h; however, trends toward prolonged blood retention in the IL group were seen.

Outcomes associated with amiodarone and lidocaine for the treatment of adult in-hospital cardiac arrest with shock-refractory pulseless ventricular tachyarrhythmia

BACKGROUND

To determine the association between amiodarone or lidocaine and outcomes in adult in-hospital cardiac arrest (IHCA) with shock-refractory ventricular fibrillation (VF) or pulseless ventricular tachycardia (pVT).

METHODS

A retrospective study in a single medical centre was conducted. Patients experiencing an IHCA between 2006 and 2015 were screened. Shock-refractory ventricular tachyarrhythmias were defined as VF/pVT requiring more than one defibrillation attempt. A multivariate logistic regression analysis was used to study the associations between the independent variables and outcomes.

RESULTS

A total of 130 patients were included. Among these, 113 patients (86.9%) were administered amiodarone as the first antiarrhythmic agent (amiodarone first) following VF/pVT, and the other patients were administered lidocaine (lidocaine first). The median time to the first defibrillation and first antiarrhythmic drug administration were 2 and 9 min, respectively. The analysis demonstrated that the amiodarone-first group experienced a higher likelihood of terminating the VF/pVT within three shocks (odds ratio: 11.61, 95% confidence interval: 1.34-100.84; p-value = 0.03), as compared with the lidocaine-first group. However, there were no significant differences between the amiodarone- and lidocaine-first groups in sustained return of spontaneous circulation, survival for 24 h, survival, or favourable neurological outcomes at hospital discharge.

CONCLUSION

For patients with IHCA and shock-refractory VF/pVT, the adoption of an amiodarone-first strategy seemed to be associated with the termination of VF/pVT using fewer shocks. Nonetheless, because of the small sample size, additional large-scale studies should be conducted to investigate whether this advantage could be translated into a long-term benefit in survival or neurological outcomes.

Effectiveness of antiarrhythmic drugs for shockable cardiac arrest: A systematic review

PURPOSE

The purpose of this systematic review is to provide up-to-date evidence on effectiveness of antiarrhythmic drugs for shockable cardiac arrest to help inform the 2018 International Liaison Committee on Resuscitation Consensus on Science with Treatment Recommendations.

METHODS

A search was conducted in electronic databases Medline, Embase, and Cochrane Library from inception to August 15, 2017.

RESULTS

Of the 9371 citations reviewed, a total of 14 RCTs and 17 observational studies met our inclusion criteria for adult population and only 1 observational study for pediatric population. Based on RCT level evidence for adult population, none of the anti-arrhythmic drugs showed any difference in effect compared with placebo, or with other anti-arrhythmic drugs for the critical outcomes of survival to hospital discharge and discharge with good neurological function. For the outcome of return of spontaneous circulation, the results showed a significant increase for lidocaine compared with placebo (RR = 1.16; 95% CI, 1.03-1.29, p = 0.01).

CONCLUSION

The high level evidence supporting the use of antiarrhythmic drugs during CPR for shockable cardiac arrest is limited and showed no benefit for critical outcomes of survival at hospital discharge, survival with favorable neurological function and long-term survival. Future high quality research is needed to confirm these findings and also to evaluate the role of administering antiarrhythmic drugs in children with shockable cardiac arrest, and in adults immediately after ROSC.

Meta-analysis of the efficacies of amiodarone and nifekalant in shock-resistant ventricular fibrillation and pulseless ventricular tachycardia

Amiodarone (AMD) and nifekalant (NIF) are used in the treatment of ventricular fibrillation or tachycardia; however, only few studies have been conducted on their efficacies. Therefore, a meta-analysis was conducted. Relevant sources were identified from PubMed, Cochrane Central Register of Controlled Trials, and Igaku Chuo Zasshi. The outcomes were short-term and long-term survival in patients with shock-resistant ventricular fibrillation /pulseless ventricular tachycardia. Thirty-three studies were analysed. The results showed that, compared to the control treatment, AMD did not improve short-term survival (odds ratio (OR): 1.25, 95% confidence interval (CI): 0.91-1.71) or long-term survival (OR: 1.00, 95% CI: 0.63-1.57). However, compared to the control treatment, NIF significantly improved short-term survival (OR: 3.23, 95% CI: 2.21-4.72) and long-term survival (OR: 1.88, 95% CI: 1.36-2.59). No significant difference was observed in short-term survival (OR: 0.85, 95% CI: 0.63-1.15) or long-term survival (OR: 1.25, 95% CI: 0.67-2.31) between AMD- and NIF-treated patients. The results suggest that NIF is beneficial for short-term and long-term survival in shock-resistant ventricular fibrillation/pulseless ventricular tachycardia; however, the efficacy of AMD in either outcome is not clear.

Amiodarone, lidocaine, magnesium or placebo in shock refractory ventricular arrhythmia: A Bayesian network meta-analysis

Recent evidence challenges, the superiority of amiodarone, compared to other anti-arrhythmic medications, as the agent of choice in pulseless ventricular tachycardia (VT) or ventricular fibrillation (VF). We conducted Bayesian network and traditional meta-analyses to investigate the relative efficacies of amiodarone, lidocaine, magnesium (MgSO4) and placebo as treatments for pulseless VT or VF. Eleven studies [5200 patients, 7 randomized trials (4, 611 patients) and 4 non-randomized studies (589 patients)], were included in this meta-analysis. The search was conducted, from 1981 to February 2017, using MEDLINE, EMBASE and The Cochrane Library. Estimates were reported as odds ratio (OR) with 95% Credible Interval (CrI). Markov chain Monte Carlo (MCMC) modeling was used to estimate the relative ranking probability of each treatment group based on surface under cumulative ranking curve (SUCRA). Bayesian analysis demonstrated that lidocaine had superior effects on survival to hospital discharge, compared to amiodarone (OR, 2.18, 95% Cr.I 1.26-3.13), MgSO4 (OR, 2.03, 95% Cr.I 0.74-4.82) and placebo (OR, 2.42, 95% Cr.I 1.39-3.54). There were no statistical differences among treatment groups regarding survival to hospital admission/24 h (hrs) and return of spontaneous circulation (ROSC). Probability analysis revealed that lidocaine was the most effective therapy for survival to hospital discharge (SUCRA, 97%). We conclude that lidocaine may be the most effective anti-arrhythmic agent for survival to hospital discharge in patients with pulseless VT or VF.

Acute hospital administration of amiodarone and/or lidocaine in shockable patients presenting with out-of-hospital cardiac arrest: A nationwide cohort study

BACKGROUND

Terminating ventricular fibrillation (VF) or pulseless ventricular tachyarrhythmia (VT) is critical for successful resuscitation of patients with shockable cardiac arrest. In the event of shock-refractory VF, applicable guidelines suggest use of anti-arrhythmic agents. However, subsequent long-term outcomes remain unclear. A nationwide cohort study was therefore launched, examining 1-year survival rates in patients given amiodarone and/or lidocaine for cardiac arrest.

METHODS

Medical records accruing between years 2004 and 2011 were retrieved from the Taiwan National Health Insurance Research Database (NHIRD) for review. This repository houses all insurance claims data for nearly the entire populace (>99%). Candidates for study included all non-traumatized adults receiving DC shock and cardiopulmonary resuscitation immediately or within 6h of emergency room arrival. Analysis was based on data from emergency rooms and hospitalization.

RESULTS

One-year survival rates by treatment group were 8.27% (534/6459) for amiodarone, 7.15% (77/1077) for lidocaine, 11.10% (165/1487) for combined amiodarone/lidocaine use, and 3.26% (602/18,440) for use of neither amiodarone nor lidocaine (all, p<0.0001). Relative to those given neither medication, odds ratios for 1-year survival via multiple regression analysis were 1.84 (95% CI: 1.58-2.13; p<0.0001) for amiodarone, 1.88 (95% CI: 1.40-2.53; p<0.0001) for lidocaine, and 2.18 (95% CI: 1.71-2.77; p<0.0001) for dual agent use.

CONCLUSIONS

In patients with shockable cardiac arrest, 1-year survival rates were improved with association of using amiodarone and/or lidocaine, as opposed to non-treatment. However, outcomes of patients given one or both medications did not differ significantly in intergroup comparisons.

Amiodarone and cardiac arrest: Systematic review and meta-analysis

INTRODUCTION

The 2015 Guidelines for Resuscitation recommend amiodarone as the antiarrhythmic drug of choice in the treatment of resistant ventricular fibrillation or pulseless ventricular tachycardia. We reviewed the effects of amiodarone on survival and neurological outcome after cardiac arrest.

METHODS

We systematically searched MEDLINE and Cochrane Library from 1940 to March 2016 without language restrictions. Randomized control trials (RCTs) and observational studies were selected.

RESULTS

Our search initially identified 1663 studies, 1458 from MEDLINE and 205 from Cochrane Library. Of them, 4 randomized controlled studies and 6 observational studies met the inclusion criteria and were selected for further review. Three randomized studies were included in the meta-analysis. Amiodarone significantly improves survival to hospital admission (OR=1.402, 95% CI: 1.068-1.840, Z=2.43, P=0.015), but neither survival to hospital discharge (RR=0.850, 95% CI: 0.631-1.144, Z=1.07, P=0.284) nor neurological outcome compared to placebo or nifekalant (OR=1.114, 95% CI: 0.923-1.345, Z=1.12, P=0.475).

CONCLUSIONS

Amiodarone significantly improves survival to hospital admission. However there is no benefit of amiodarone in survival to discharge or neurological outcomes compared to placebo or other antiarrhythmics.

Resuscitation Outcomes Consortium-Amiodarone, Lidocaine or Placebo Study (ROC-ALPS): Rationale and methodology behind an out-of-hospital cardiac arrest antiarrhythmic drug trial

BACKGROUND

Despite their wide use, whether antiarrhythmic drugs improve survival after out-of-hospital cardiac arrest (OHCA) is not known. The ROC-ALPS is evaluating the effectiveness of these drugs for OHCA due to shock-refractory ventricular fibrillation or pulseless ventricular tachycardia (VF/VT).

METHODS

ALPS will randomize 3,000 adults across North America with nontraumatic OHCA, persistent or recurring VF/VT after ≥1 shock, and established vascular access to receive up to 450 mg amiodarone, 180 mg lidocaine, or placebo in the field using a double-blind protocol, along with standard resuscitation measures. The designated target population is all eligible randomized recipients of any dose of ALPS drug whose initial OHCA rhythm was VF/VT. A safety analysis includes all randomized patients regardless of their eligibility, initial arrhythmia, or actual receipt of ALPS drug. The primary outcome of ALPS is survival to hospital discharge; a secondary outcome is functional survival at discharge assessed as a modified Rankin Scale score ≤3.

RESULTS

The principal aim of ALPS is to determine if survival is improved by amiodarone compared with placebo; secondary aim is to determine if survival is improved by lidocaine vs placebo and/or by amiodarone vs lidocaine. Prioritizing comparisons in this manner acknowledges where differences in outcome are most expected based on existing knowledge. Each aim also represents a clinically relevant comparison between treatments that is worth investigating.

CONCLUSIONS

Results from ALPS will provide important information about the choice and value of antiarrhythmic therapies for VF/VT arrest with direct implications for resuscitation guidelines and clinical practice.

Pharmacotherapy of pediatric advanced life support and toxicological emergencies

Guidelines for pediatric advanced life support have been available for nearly a quarter of a century. Recommendations for the pharmacological management of pediatric cardiac arrest have changed over these years. Several important differences have been observed between adult advanced cardiac life support and pediatric advanced life support that must be recognized when children require resuscitation, such as the cause of the arrest, age-specific monitoring parameters, weight-based medication dosing, and obstacles in obtaining venous access. To make matters more complicated, differences also exist across neonatal and pediatric age spectrums. In addition, some toxicological emergencies commonly occurring in children require pharmacological management with agents that have a unique mechanism of action for cardiac support.

Antiarrhythmia drugs for cardiac arrest: a systemic review and meta-analysis

INTRODUCTION

Antiarrhythmia agents have been used in the treatment of cardiac arrest, and we aimed to review the relevant clinical controlled trials to assess the effects of antiarrhythmics during cardiopulmonary resuscitation.

METHODS

We searched databases including Cochrane Central Register of Controlled Trials; MEDLINE, and EMBASE. Clinical controlled trials that addressed the effects of antiarrhythmics (including amiodarone, lidocaine, magnesium, and other new potassium-channel blockers) on the outcomes of cardiac arrest were included. Data were collected independently by two authors. The risk ratio of each outcome was collected, and meta-analysis was used for data synthesis if appropriate. Heterogeneity was assessed with the χ² test and the I² test.

RESULTS

Ten randomized controlled trials and seven observational trials were identified. Amiodarone (relative risk (RR), 0.82; 95% confidence interval (CI), 0.54 to 1.24), lidocaine (RR, 2.26; 95% CI, 0.93 to 5.52), magnesium (RR, 0.82; 95% CI, 0.54 to 1.24) and nifekalant were not shown to improve the survival to hospital discharge compared with placebo, but amiodarone, lidocaine, and nifekalant were shown to be beneficial to initial resuscitation, assessed by the rate of return of spontaneous circulation and survival to hospital admission, with amiodarone being superior to lidocaine (RR, 1.28; 95% CI, 0.57 to 2.86) and nifekalant (RR, 0.50; 95% CI, 0.19 to 1.31). Bretylium and sotalol were not shown to be beneficial.

CONCLUSIONS

Our review suggests that when administered during resuscitation, antiarrhythmia agents might not improve the survival to hospital discharge, but they might be beneficial to initial resuscitation. This is consistent with the AHA 2010 guidelines for resuscitation and cardiovascular emergency, but more studies with good methodologic quality and large numbers of patients are still needed to make further assessment.

The use of antiarrhythmic drugs for adult cardiac arrest: a systematic review

AIMS

In adult cardiac arrest, antiarrhythmic drugs are frequently utilized in acute management and legions of medical providers have memorized the dosage and timing of administration. However, data supporting their use is limited and is the focus of this comprehensive review.

METHODS

Databases including PubMed, Cochrane Library (including Cochrane database for systematic reviews and Cochrane Central Register of Controlled Trials), Embase, and AHA EndNote Master Library were systematically searched. Further references were gathered from cross-references from articles and reviews as well as forward search using SCOPUS and Google scholar. The inclusion criteria for this review included human studies of adult cardiac arrest and anti-arrhythmic agents, peer-review. Excluded were review articles, case series and case reports.

RESULTS

Of 185 articles found, only 25 studies met the inclusion criteria for further review. Of these, 9 were randomised controlled trials. Nearly all trials solely evaluated Ventricular Tachycardia (VT) and Ventricular Fibrillation (VF), and excluded Pulseless Electrical Activity (PEA) and asystole. In VT/VF patients, amiodarone improved survival to hospital admission, but not to hospital discharge when compared to lidocaine in two randomized controlled trials.

CONCLUSION

Amiodarone may be considered for those who have refractory VT/VF, defined as VT/VF not terminated by defibrillation, or VT/VF recurrence in out of hospital cardiac arrest or in-hospital cardiac arrest. There is inadequate evidence to support or refute the use of lidocaine and other antiarrythmic agents in the same settings.

Part 8: adult advanced cardiovascular life support: 2010 American Heart Association Guidelines for Cardiopulmonary Resuscitation and Emergency Cardiovascular Care

The goal of therapy for bradycardia or tachycardia is to rapidly identify and treat patients who are hemodynamically unstable or symptomatic due to the arrhythmia. Drugs or, when appropriate, pacing may be used to control unstable or symptomatic bradycardia. Cardioversion or drugs or both may be used to control unstable or symptomatic tachycardia. ACLS providers should closely monitor stable patients pending expert consultation and should be prepared to aggressively treat those with evidence of decompensation.

Comparative study of nifekalant versus amiodarone for shock-resistant ventricular fibrillation in out-of-hospital cardiopulmonary arrest patients

BACKGROUND

In Japan, intravenous nifekalant (NIF) was often used for direct current cardioversion-resistant ventricular fibrillation (VF), until the use of intravenous amiodarone (AMD) was approved in 2007. The defibrillatory efficacy of NIF and AMD has thus far not been compared for resuscitation.

METHODS AND RESULTS

Between August 2007 and April 2009, 403 consecutive out-of-hospital patients with cardiopulmonary arrest were transferred to the Emergency Medical Service of Tokai University. Of these, 30 patients with first defibrillation failure or VF recurrence were enrolled for this NIF/AMD study. The final defibrillation success (and hospital survival rate) was 67% (10/15) in the AMD and 47% (7/15) in the NIF group. The discharge survival rate was 53% (8/15) in the AMD and 21% (4/15) in the NIF group (P = 0.06). Notably, all 4 survivors in the NIF group could take up normal daily life again, whereas this was restricted to only 2 patients from the 11 survivors in the AMD group. The difference is probably partly attributable to longer time from AMD administration to defibrillation success compared with NIF. In the cases of defibrillation failure, VF continued in 4/8 by NIF, however, asystole or pulseless electrical activity occurred in 4/5 patients by AMD.

CONCLUSIONS

AMD may be borderline superior over NIF to facilitate defibrillation in out-of-hospital patients with cardiopulmonary arrest. However, from the view point of preservation of brain function, NIF is not inferior to AMD for CPR.

Comparison of the efficacy of nifekalant and amiodarone in a porcine model of cardiac arrest

OBJECTIVE

To compare the efficacy of nifekalant and amiodarone in the treatment of cardiac arrest in a porcine model.

METHODS

After 4min of untreated ventricular fibrillation, animals were randomly treated with nifekalant (2mgkg(-1)), amiodarone (5mgkg(-1)) or saline placebo (n=12 pigs per group). Precordial compression and ventilation were initiated after drug administration and defibrillation was attempted 2min later. Hemodynamics were continuously measured for 6h after successful resuscitation.

RESULTS

Compared with saline, nifekalant and amiodarone equally decreased the number of electric shocks, defibrillation energy, epinephrine dose, and duration of cardiopulmonary resuscitation required for successful resuscitation (P<0.01). The incidence of restoration of spontaneous circulation (ROSC) and the 24-h survival rate were higher in both antiarrhythmic drug groups (P<0.05) vs. the saline group. Furthermore, post-resuscitation myocardial dysfunction at 4-6h after successful resuscitation was improved in animals given antiarrhythmic drugs as compared with the saline group (P<0.05). There were no differences between nifekalant and amiodarone for any of these parameters.

CONCLUSION

The effect of nifekalant was similar to that of amiodarone for improving defibrillation efficacy and for the treatment of cardiac arrest. Administration of either nifekalant or amiodarone before defibrillation increased the ROSC and 24-h survival rates and improved post-resuscitation cardiac function in this porcine model.

Pharmacotherapy considerations in advanced cardiac life support

Cardiac arrest and sudden cardiac death remain major causes of mortality. Early intervention has been facilitated by emergency medical response systems and the development of training programs in basic life support and advanced cardiac life support (ACLS). Despite the implementation of these programs, the likelihood of a meaningful outcome in many life-threatening situations remains poor. Pharmacotherapy plays a role in the management of patients with cardiac arrest, with new guidelines for ACLS available in 2005 providing recommendations for the role of specific drug therapies. Epinephrine continues as a recommended means to facilitate defibrillation in patients with pulseless ventricular tachycardia or ventricular fibrillation; vasopressin is an alternative. Amiodarone is the primary antiarrhythmic drug that has been shown to be effective for facilitation of defibrillation in patients with pulseless ventricular tachycardia or fibrillation and is also used for the management of atrial fibrillation and hemodynamically stable ventricular tachycardia. Epinephrine and atropine are the primary agents used for the management of asystole and pulseless electrical activity. Treatment of electrolyte abnormalities, severe hypotension, pulmonary embolism, acute ischemic stroke, and toxicologic emergencies are important components of ACLS management. Selection of the appropriate drug, dose, and timing and route of administration are among the many challenges faced in this setting. Pharmacists who are properly educated and trained regarding the use of pharmacotherapy for patients requiring ACLS can help maximize the likelihood of positive patient outcomes.

Outcome after heroin overdose and cardiopulmonary resuscitation

BACKGROUND

The survival of heroin overdose patients resuscitated from cardiac arrest is reported to be poor. The aim of our study was to investigate the outcome and characteristics of survivors after cardiac arrest caused by heroin overdose.

METHODS

This was a retrospective study in a medium-sized city (population, 560,000). Between 1 January 1997 and 31 December 2000, there were 94 combined cardiac arrests caused by acute drug poisonings. The main outcome measure was survival to discharge.

RESULTS

Cardiopulmonary resuscitation was attempted in 19 heroin overdose patients (group A) and in 53 patients with cardiac arrest caused by other poisonings (group B). Three (16%) vs. six (11%) patients were discharged alive (group A vs. B, respectively). The survivors in group A had an Emergency Medical Service (EMS)-witnessed cardiac arrest or the Emergency Dispatching Centre was called before the arrest occurred. There was no statistically significant difference between the two groups in terms of survival. Survivors in both groups suffered from acute renal failure (two), hypoglycaemia (four) and hypothermia (three).

CONCLUSION

Survival after cardiac arrest caused by heroin overdose is possible if the arrest is EMS witnessed or the Emergency Dispatching Centre is called before the cardiac arrest occurs. In comparison with cardiac arrests caused by other poisonings, there was no difference in survival. The incidence and mechanism of hypoglycaemia should be examined in further studies.

Comparing intravenous amiodarone or lidocaine, or both, outcomes for inpatients with pulseless ventricular arrhythmias*

OBJECTIVE

To compare survival rates of patients with in-hospital cardiac arrest due to pulseless ventricular tachycardia/ventricular fibrillation treated with lidocaine, amiodarone, or amiodarone plus lidocaine.

DESIGN

Multicenter retrospective medical record review.

SETTING

Three academic medical centers in the United States.

PATIENTS

Hospitalized adult patients who received amiodarone, lidocaine, or a combination for pulseless ventricular tachycardia/ventricular fibrillation between August 1, 2000, and July 31, 2002.

MEASUREMENTS AND MAIN RESULTS

Data were collected according to the Utstein style. In-hospital proportion of patients living at 24 hrs and discharge were analyzed using chi-square analysis. Of the 605 patient medical records reviewed, 194 met criteria for inclusion (n=79 for lidocaine, n=74 for amiodarone, n=41 for combination). Available data showed no difference in proportion of patients alive 24 hrs post-cardiac arrest (p=.39). Cox regression analysis indicated a decreased likelihood of survival in patients with pulseless ventricular tachycardia/ventricular fibrillation as an initial rhythm as compared with those who presented with bradycardia followed by pulseless ventricular tachycardia/ventricular fibrillation and in those patients who received amiodarone as compared with lidocaine. However, only 14 patients (25%) in the amiodarone group received the recommended initial 300-mg intravenous bolus, and amiodarone was administered an average of 8 mins later in the code compared with lidocaine (p<.001).

CONCLUSIONS

These results generate the hypothesis that inpatients with cardiac arrest may have different benefits from lidocaine and amiodarone than previously demonstrated. Inadequate dosing and later administration of amiodarone in the code were two confounding factors in this study. Prospective studies evaluating these agents are warranted.