Comparison of nifekalant and amiodarone for resuscitation of out-of-hospital cardiopulmonary arrest resulting from shock-resistant ventricular fibrillation

Long-term nifekalant use in a patient with dilated cardiomyopathy and recurrent ventricular tachycardia

The potential utility of nifekalant, a new Class III antiarrhythmic drug, to offer long-term protection against ventricular arrhythmia has been investigated in this case report. A 44-year-old male patient with dilated cardiomyopathy complicated with heart failure and persistent ventricular tachycardia was treated with nifekalant. The patient was treated with nifekalant for 31 days, which effectively terminated ventricular tachycardia and maintained sinus rhythm, with no clinical adverse reactions. After heart transplantation, postoperative follow-up showed good cardiac function and no arrhythmia. On the basis of nifekalant’s working mechanism, there is a good chance that it can cure ventricular arrhythmia on a long-term basis.

The first case series analysis on efficacy of esmolol injection for in-hospital cardiac arrest patients with refractory shockable rhythms in China

Background: This study assessed the effects of esmolol injection in patients with in-hospital cardiac arrest (IHCA) with refractory ventricular fibrillation (VF)/pulseless ventricular tachycardia (pVT).

Methods: From January 2018 to December 2021, 29 patients with IHCA with refractory shockable rhythm were retrospectively reviewed. Esmolol was administered after advanced cardiovascular life support (ACLS)-directed procedures, and outcomes were assessed.

Results: Among the 29 cases, the rates of sustained return of spontaneous circulation (ROSC), 24-h ROSC, and 72-h ROSC were 79%, 62%, and 59%, respectively. Of those patients, 59% ultimately survived to discharge. Four patients with cardiac insufficiency died. The duration from CA to esmolol infusion was significantly shorter for patients in the survival group (SG) than for patients in the dead group (DG) (12 min, IQR: 8.5–19.5 vs. 23.5 min, IQR: 14.4–27 min; p = 0.013). Of those patients, 76% (22 of 29) started esmolol administration after the second dose of amiodarone. No significant difference was observed in the survival rate between this group and groups administered an esmolol bolus simultaneously or before the second dose of amiodarone (43% vs. 64%, p = 0.403). Of those patients, 31% (9 of 29) were administered an esmolol bolus for defibrillation attempts ≤ 5, while the remaining 69% of patients received an esmolol injection after the fifth defibrillation attempt. No significant differences were observed in the rates of ≥ 24-h ROSC (67% vs. 60%, p = 0.73), ≥ 72-h ROSC (67% vs. 55%, p = 0.56), and survival to hospital discharge (67% vs. 55%, p = 0.56) between the groups administered an esmolol bolus for defibrillation attempts ≤ 5 and defibrillation attempts > 5.

Conclusion: IHCA patients with refractory shockable rhythms receiving esmolol bolus exhibited a high chance of sustained ROSC and survival to hospital discharge. Patients with end-stage heart failure tended to have attenuated benefits from beta-blockers. Further large-scale, prospective studies are necessary to determine the effects of esmolol in patients with IHCA with refractory shockable rhythms.

Efficacy of AutoPulse for Mechanical Chest Compression in Patients with Shock-Resistant Ventricular Fibrillation

INTRODUCTION

Sudden cardiac arrest is one of the most common causes of death. In cases of shock-resistant ventricular fibrillation, immediate transport of patients to the hospital is essential and made possible with use of devices for mechanical chest compression.

OBJECTIVES

The efficacy of AutoPulse in patients with shock-resistant ventricular fibrillation was studied.

METHODS

This is a multicentre observational study on a population of 480,000, with 192 reported cases of out-of-hospital cardiac arrest. The study included patients with shock-resistant ventricular fibrillation defined as cardiac arrest secondary to ventricular fibrillation requiring ≥3 consecutive shocks. Eventually, 18 patients met the study criteria.

RESULTS

The mean duration of resuscitation was 48.4±43 min, 55% of patients were handed over to the laboratory while still in cardiac arrest, 83.3% of them underwent angiography and, in 93.3% of them, infarction was confirmed. Coronary intervention was continued during mechanical resuscitation in 50.0% of patients, 60% of patients survived the procedure, and 27.8% of the patients survived.

CONCLUSIONS

Resistant ventricular fibrillation suggests high likelihood of a coronary component to the cardiac arrest. AutoPulse is helpful in conducting resuscitation, allowing the time to arrival at hospital to be reduced.

Anesthetic management of a patient with severe aortic regurgitation undergoing reoperation for ascending aorta false aneurysm using hypothermia: prevention of ventricular fibrillation by nifekalant

BACKGROUND

To prevent cardiac collapse and to protect cerebral function, hypothermic cardiopulmonary bypass is established before resternotomy. However, ventricular fibrillation under hypothermia facilitates left ventricular distension, which causes irreversible myocardial damage when the patient has aortic regurgitation. We report a case of successful management in preventing ventricular fibrillation under hypothermia by using nifekalant.

CASE PRESENTATION

A 56-year-old male, who had been performed a David operation, was scheduled for a Bentall operation for a pseudo aortic aneurysm with severe aortic regurgitation. After inducing anesthesia, we administered intravenous nifekalant and a vent tube was inserted into the left ventricle under one-lung ventilation. Extracorporeal circulation was established and resternotomy started after cooling to 27 °C. Although severe bradycardia and QT prolongation were observed, ventricular fibrillation did not occur until aortic cross-clamping.

CONCLUSION

Combining maintaining cerebral perfusion and avoiding left ventricle distension during hypothermia was successfully managed with nifekalant in our redo cardiac patient with aortic regurgitation.

Refractory ventricular arrhythmias during aortic valve replacement and cardiac artery bypass requiring 16 attempts of electrical cardioversion: a case report

BACKGROUND

We report a patient in whom we failed to suppress ventricular fibrillation (VF) using nifekalant but succeeded using amiodarone during cardiopulmonary bypass (CPB).

CASE PRESENTATION

A 65-year-old male with hemodialysis complained of dyspnea and was diagnosed with aortic valve stenosis and angina pectoris; he was opted for elective aortic valve replacement. When the aortic forceps were declamped during CPB, immediate VF was observed; several attempts of electrical cardioversion (EC) with lidocaine and landiolol and three administrations of nifekalant were temporarily effective. However, the rhythm subsequently changed to torsades de pointes. We administered 2 g of magnesium sulfate followed by three doses of amiodarone and initiated continuous infusion. Furthermore, we initiated the pacemaker and intra-aortic balloon pumping. These procedures seemed to be effective; the sinus rhythm was sustained until the end of the surgery.

CONCLUSION

We experienced a cardiac surgery requiring 16 EC attempts to terminate the life-threatening arrhythmias using amiodarone.

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.

Drugs in cardiac arrest: the rise and fall of antiarrhythmics

Since the publication of 2000 guidelines for resuscitation, amiodarone is considered the antiarrhythmic drug of choice for refractory ventricular fibrillation/pulseless ventricular tachycardia. However, to date there is no proven benefit in terms of neurologically intact survival to hospital discharge. A comprehensive search of the recent literature on amiodarone, nifekalant and lidocaine in cardiac arrest was performed. Amiodarone and nifekalant are superior to lidocaine with regards to the return of spontaneous circulation and survival to hospital admission. Nifekalant shows a trend towards quicker termination of ventricular fibrillation compared to amiodarone. There is great uncertainty about the efficacy of antiarrhythmics in cardiac arrest. Failure to show improvements regarding meaningful survival questions their current use and suggests the need for re-evaluating their place in cardiopulmonary resuscitation.

Does Antiarrhythmic Drug During Cardiopulmonary Resuscitation Improve the One-month Survival: The SOS-KANTO 2012 Study

BACKGROUND

Antiarrhythmic drugs (AAD) are often used for fatal ventricular arrhythmias during cardiopulmonary resuscitation (CPR). However, the efficacy of initial AAD administration during CPR in improving long-term prognosis remains unknown. This study retrospectively evaluated the effect of AAD administration during CPR on 1-month prognosis in the SOS-KANTO 2012 study population.

METHODS AND RESULTS

Of the 16,164 out-of-hospital cardiac arrest cases, 1350 shock-refractory patients were included: 747 patients not administered AAD and 603 patients administered AAD. Statistical adjustment for potential selection bias was performed using propensity score matching, yielding 1162 patients of whom 792 patients were matched (396 pairs). The primary outcome was 1-month survival. The secondary outcome was the proportion of patients with favorable neurological outcome at 1 month. Logistic regression with propensity scoring demonstrated an odds ratio (OR) for 1-month survival in the AAD group of 1.92 (P < 0.01), whereas the OR for favorable neurological outcome at 1 month was 1.44 (P = 0.26).

CONCLUSIONS

Significantly greater 1-month survival was observed in the AAD group compared with the non-AAD group. However, the effect of ADD on the likelihood of a favorable neurological outcome remains unclear. The findings of the present study may indicate a requirement for future randomized controlled trials evaluating the effect of ADD administration during CPR on long-term prognosis.

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.

Recent advances in the management of ventricular tachyarrhythmias

Ventricular arrhythmias are an important cause of cardiovascular morbidity and mortality, particularly in those with structural heart disease, inherited cardiomyopathies, and channelopathies. The goals of ventricular arrhythmia management include symptom relief, improving quality of life, reducing implantable cardioverter defibrillator shocks, preventing deterioration of left ventricular function, reducing risk of arrhythmic death, and potentially improving overall survival. Guideline-directed medical therapy and implantable cardioverter defibrillator implantation remain the mainstay of therapy to prevent sudden cardiac death in patients with ventricular arrhythmias in the setting of structural heart disease. Recent advances in imaging modalities and commercial availability of genetic testing panels have enhanced our mechanistic understanding of the disease processes and, along with significant progress in catheter-based ablative therapies, have enabled a tailored and more effective management of drug-refractory ventricular arrhythmias. Several gaps in our knowledge remain and require further research. In this article, we review the recent advances in the diagnosis and management of ventricular arrhythmias.

Antiarrhythmic drugs for out-of-hospital cardiac arrest with refractory ventricular fibrillation

This article is one of ten reviews selected from the Annual Update in Intensive Care and Emergency medicine 2017. Other selected articles can be found online at http://ccforum.com/series/annualupdate2017. Further information about the Annual Update in Intensive Care and Emergency Medicine is available from http://www.springer.com/series/8901.

Nifekalant Versus Amiodarone in the Treatment of Cardiac Arrest: an Experimental Study in a Swine Model of Prolonged Ventricular Fibrillation

PURPOSE

The purpose of the experiment was to compare the effects of nifekalant and amiodarone on the return of spontaneous circulation (ROSC), survival, as well as on the hemodynamic parameters in a swine model of prolonged ventricular fibrillation (VF).

METHODS

After 8 min of untreated VF, bolus doses of epinephrine (adrenaline) and either nifekalant, or amiodarone, or saline (n = 10 per group), were administered after randomization. Cardiopulmonary resuscitation (CPR) was commenced immediately after drug administration and defibrillation was attempted 2 min later. CPR was resumed for another 2 min after each defibrillation attempt and the same dose of adrenaline was given every 4th minute during CPR.

RESULTS

Forty-eight hour survival was significantly higher with nifekalant compared to amiodarone (p < 0.001) and saline (p = 0.02), (9/10 vs. 0/10 vs. 3/10, respectively). Systolic aortic pressure, diastolic aortic pressure and coronary perfusion pressure were significantly higher with nifekalant during CPR and immediate post-resuscitation period (p < 0.05). The animals in the amiodarone group had a slower heart rate at the 1st and 45th min post-ROSC (p < 0.001 and p = 0.006, respectively). The number of electric shocks required for terminating VF, time to ROSC and adrenaline dose were significantly higher with amiodarone compared to nifekalant (p < 0.001).

CONCLUSIONS

Nifekalant showed a more favorable hemodynamic profile and improved survival compared to amiodarone and saline in this swine model.

Amiodarone or nifekalant upon hospital arrival for refractory ventricular fibrillation after out-of-hospital cardiac arrest

BACKGROUND

We evaluated the association between nifekalant or amiodarone on hospital admission and in-hospital mortality for cardiac arrest patients with persistent ventricular fibrillation on hospital arrival.

METHODS

This was a retrospective cohort study using the Japanese Diagnosis Procedure Combination inpatient database. We identified 2961 patients who suffered cardiogenic out-of-hospital cardiac arrest and who had ventricular fibrillation on hospital arrival between July 2007 and March 2013. Patients were categorized into amiodarone (n=2353) and nifekalant (n=608) groups, from which 525 propensity score-matched pairs were generated.

RESULTS

We found a significant difference in the admission rate between the nifekalant and amiodarone groups in propensity score-matched groups (75.6% vs. 69.3%, respectively; difference, 6.3%; 95% confidence interval (CI), 0.9-11.7). An analysis using the hospital nifekalant/amiodarone rate as an instrumental variable found that receiving nifekalant was associated with an improved admission rate (22.2%, 95% CI, 11.9-32.4). We found no significant difference in in-hospital mortality between the nifekalant and amiodarone groups (81.5% vs. 82.1%, respectively; difference, -0.6%; 95% CI, -5.2 to 4.1). Instrumental variable analysis showed that receiving nifekalant was not associated with reduced in-hospital mortality (6.2%, 95% CI, -2.4 to 14.8).

CONCLUSIONS

This nationwide study suggested no significant in-hospital mortality association between nifekalant and amiodarone for cardiogenic out-of-hospital cardiac arrest patients with ventricular fibrillation/persistent ventricular tachycardia on hospital arrival. Although nifekalant may potentially improve hospital admission rates compared with amiodarone for these patients, further studies are required to confirm our results.

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.

[Drug Therapy for Shock-Resistant Ventricular Fibrillation: Comparison of Nifekalant and Amiodarone]

Early direct current (DC) shock is the most important therapy for ventricular fibrillation. Following the increased availability of automated external defibrillators (AED), the survival rate of cardiopulmonary arrest patients with ventricular fibrillation has improved. Although patients with shock-resistant ventricular fibrillation require additional antiarrhythmic drug therapy, the optimal protocol has not been established. Nifekalant is a pure potassium channel blocker with a pyrimidinedione structure. Nifekalant was approved in Japan for the treatment of life-threatening ventricular tachyarrhythmias in 1999, and is widely used as a class III antiarrhythmic intravenous drug. Intravenous amiodarone was approved in Japan in 2007, and exhibits various effects on ion channels, receptors, sympathetic activity, and thyroid function. Nifekalant and amiodarone also exhibit many pharmacological and pharmacodynamic differences. As nifekalant has no negative inotropic effect and a rapid action and clearance with a short half-life, it has some advantages over amiodarone for use in cardiopulmonary resuscitation. Indeed, data from clinical and animal studies suggest that nifekalant is superior to amiodarone for resuscitation of cardiopulmonary arrest resulting from shock-resistant ventricular fibrillation. A 300-mg bolus intravenous injection of amiodarone is considered an overdose for resuscitation of shock-resistant ventricular fibrillation. Further clinical studies are required to evaluate the effects of nifekalant compared with amiodarone, and to determine the optimal dose of amiodaone, for resuscitation of shock-resistant ventricular fibrillation.

Managing cardiac arrest with refractory ventricular fibrillation in the emergency department: Conventional cardiopulmonary resuscitation versus extracorporeal cardiopulmonary resuscitation

AIM

Refractory ventricular fibrillation, resistant to conventional cardiopulmonary resuscitation (CPR), is a life threatening rhythm encountered in the emergency department. Although previous reports suggest the use of extracorporeal CPR can improve the clinical outcomes in patients with prolonged cardiac arrest, the effectiveness of this novel strategy for refractory ventricular fibrillation is not known. We aimed to compare the clinical outcomes of patients with refractory ventricular fibrillation managed with conventional CPR or extracorporeal CPR in our institution.

METHOD

This is a retrospective chart review study from an emergency department in a tertiary referral medical center. We identified 209 patients presenting with cardiac arrest due to ventricular fibrillation between September 2011 and September 2013. Of these, 60 patients were enrolled with ventricular fibrillation refractory to resuscitation for more than 10 min. The clinical outcome of patients with ventricular fibrillation received either conventional CPR, including defibrillation, chest compression, and resuscitative medication (C-CPR, n = 40) or CPR plus extracorporeal CPR (E-CPR, n = 20) were compared.

RESULTS

The overall survival rate was 35%, and 18.3% of patients were discharged with good neurological function. The mean duration of CPR was longer in the E-CPR group than in the C-CPR group (69.90 ± 49.6 min vs 34.3 ± 17.7 min, p = 0.0001). Patients receiving E-CPR had significantly higher rates of sustained return of spontaneous circulation (95.0% vs 47.5%, p = 0.0009), and good neurological function at discharge (40.0% vs 7.5%, p = 0.0067). The survival rate in the E-CPR group was higher (50% vs 27.5%, p = 0.1512) at discharge and (50% vs 20%, p = 0. 0998) at 1 year after discharge.

CONCLUSIONS

The management of refractory ventricular fibrillation in the emergency department remains challenging, as evidenced by an overall survival rate of 35% in this study. Patients with refractory ventricular fibrillation receiving E-CPR had a trend toward higher survival rates and significantly improved neurological outcomes than those receiving C-CPR.

The effects of sesame oil on the prevention of amiodarone-induced phlebitis

BACKGROUND

Phlebitis is the most common complication associated with peripheral intravenous infusion of amiodarone. The purpose of this study is to determine the effects of sesame oil on the prevention of amiodarone-induced phlebitis.

MATERIALS AND METHODS

This is a double-blind randomized controlled trial. Thirty-six patients hospitalized in a coronary care unit were randomly allocated into two groups using a convenience sampling method. Following peripheral intravenous cannulation, five drops of pure sesame oil were applied to the skin within a 10 cm radius of the infusion site prior to the administration of amiodarone in the intervention group. Sesame oil was rubbed on the skin at the infusion site every 6 h in the 24-h period of amiodarone infusion. In the control group, liquid paraffin, used as a placebo, was rubbed on the skin at the infusion site of amiodarone. Both groups were monitored for the development of phlebitis and its degree within the 24-h period of amiodarone infusion as well as 6 h after its administration. The incidence of phlebitis was confirmed and recorded by an assessor who was blind to the two groups. Data were analyzed using Statistical Package for Social Science (SPSS) version 18, and descriptive and inferential statistics such as Chi-square test, Kaplan-Meier, Hazard ratio, independent t-test, and Fisher's exact test.

RESULTS

There was a statistically significant difference between the two groups in their catheter survival after 30 h and 10 min (P < 0.001). Over 60% of the patients (61.1%) in the intervention group did not show any sign of phlebitis, while 16.7% and 22.2% of the patients manifested signs of grade 2 and 3 phlebitis, respectively. In the control group, 22.2% of the patients showed no signs of phlebitis, while 5.6%, 27.8%, and 44.4% of the patients exhibited signs of grade 2, 3, and 4 phlebitis, respectively. The statistical analysis showed significant differences in the degree of phlebitis (P = 0.006) and the onset of phlebitis development (P < 0.001) between the two groups.

CONCLUSIONS

It is recommended to apply sesame oil topically to the infusion site of amiodarone so as to reduce the rate of the development of amiodarone-related phlebitis.