BIPHASIC Trial

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BIPHASIC Trial
A Randomized Comparison of Fixed Lower Versus Escalating Higher Energy Levels for Defibrillation in Out-of-Hospital Cardiac Arrest
Background— There is little clear evidence as to the optimal energy levels for initial and subsequent shocks in biphasic waveform defibrillation. The present study compared fixed lower- and escalating higher-energy regimens for out-of-hospital cardiac arrest.
Methods and Results— The Randomized Controlled Trial to Compare Fixed Versus Escalating Energy Regimens for Biphasic Waveform Defibrillation (BIPHASIC Trial) was a multicenter, randomized controlled trial of 221 out-of-hospital cardiac arrest patients who received 1 shock given by biphasic automated external defibrillator devices that were randomly programmed to provide, blindly, fixed lower-energy (150-150-150 J) or escalating higher-energy (200-300-360 J) regimens. Patient mean age was 66.0 years; 79.6% were male. The cardiac arrest was witnessed in 63.8%; a bystander performed cardiopulmonary resuscitation in 23.5%; and initial rhythm was ventricular fibrillation/ventricular tachycardia in 92.3%. The fixed lower- and escalating higher-energy regimen cases were similar for the 106 multishock patients and for all 221 patients. In the primary analysis in multishock patients, conversion rates differed significantly (fixed lower, 24.7%, versus escalating higher, 36.6%; P=0.035; absolute difference, 11.9%; 95% CI, 1.2 to 24.4). Ventricular fibrillation termination rates also were significantly different between groups (71.2% versus 82.5%; P=0.027; absolute difference, 11.3%; 95% CI, 1.6 to 20.9). For the secondary analysis of first shock success, conversion rates were similar between the fixed lower and escalating higher study groups (38.4% versus 36.7%; P=0.92), as were ventricular fibrillation termination rates (86.8% versus 88.8%; P=0.81). There were no distinguishable differences between regimens for survival outcomes or adverse effects.
Conclusions— This is the first randomized trial to compare fixed lower and escalating higher biphasic energy regimens in out-of-hospital cardiac arrest, and it demonstrated higher rates of ventricular fibrillation conversion and termination with an escalating higher-energy regimen for patients requiring multiple shocks. These results suggest that patients in ventricular fibrillation benefit from higher biphasic energy levels if multiple defibrillation shocks are required.
双相试验
题目：院外心脏骤停者应用固定低能量与逐步增加高能量除颤的随机对照试验
背景：关于双相波电除颤对于初次和随后电击该采用多大能量合适目前尚缺乏明确的证据，本研究旨在比较应用固定低能量与逐步增加高能量除颤的差异。
方法和结果：本试验为多中心，随机对照试验，共入选221例院外心脏骤停后接受超过一次以上电击的患者。采用盲法，这些患者分别应用不同能量进行体外自动除颤器除颤，分别为固定低能量（150-150-150 J）和递增高能量(200-300-360 J)。病例平均年龄66.0岁，男性占79.6%。心脏骤停时被现场目击者为63.8%，接受心肺复苏者为23.5%，初始节律为室颤或室速者占92.3%。对于接受接受多次电击的106例患者和全部221例患者，应用固定低能量和递增高能量的比例类似。接受多次电击的患者，初步分析结果显示：转复率有显著性差异（固定低能量24.7% vs递增高能量36.6%，p=0.035，绝对差异11.9%，95%CI1.2-24.4）。室颤终止率也有显著性差异（71.2% vs82.5%，p=0.027，绝对差异11.3%，95%CI，1.6~20.9）。进一步的分析结果显示，首次电击成功率和转复率类似（38.4%vs36.7%，p=0.92），室颤终止率也类似（86.8% vs 88.8%; P=0.81）。两组患者的存活率和电击的副作用没有明显的差异。
结论：本研究为第一个比较院外心脏骤停患者接受固定低能量和递增高能量双相电除颤的随机对照试验。本研究结果显示：需要接受多次电击的患者，应用递增高能量双相电除颤装置具有较高的室颤转复率和终止率。需要接受多次电击的室颤患者，采用较高能量的双相电除颤患者获益较大。