Menegazzi James J, Salcido David D, Menegazzi Michael T, Rittenberger Jon C, Suffoletto Brian P, Logue Eric S, Mader Timothy J
Department of Emergency Medicine, University of Pittsburgh School of Medicine, Pittsburgh, PA 15213, USA. menegazz+@pitt.edu
Prehosp Emerg Care. 2007 Apr-Jun;11(2):179-85. doi: 10.1080/10903120701206073.
An impedance threshold device (ITD) has been designed to enhance circulation during CPR by creating a negative intrathoracic pressure during the relaxation phase of chest compression.
We sought to determine the effects of the ITD on coronary perfusion pressure (CPP), return of spontaneous circulation (ROSC), and short-term survival (20 minutes after ROSC). We hypothesized that the ITD would improve all 3 variables when compared to standard CPR.
Using a case-control design nested within a randomized primary study, we compared CPR with the ITD (ITD-CPR) to standard CPR without the device (S-CPR). We systematically assigned 36 domestic swine, weighing 23-29 kg, (18 per group) to resuscitation with either ITD-CPR or S-CPR after 8 minutes of untreated ventricular fibrillation (VF). At minute 8, mechanical chest compression and ventilation began, and drugs (0.1 mg/kg epinephrine, 40U vasopressin, 1.0 mg propranolol, 1 mEq/kg sodium bicarbonate) were given. The first rescue shock (150J biphasic) was delivered at minute 11 of VF. We recorded CPP, ROSC (systolic pressure > 80 mmHg sustained for 60 s continuously), and survival. Data were analyzed with Fisher's exact test and generalized estimating equations (GEE), with alpha = 0.05.
We analyzed 3,150 compressions. CPP for the ITD-CPR group (28.1 mmHg [95% CI 27-29.3 mmHg]), did not differ from the S-CPR group (32.3 mmHg [95% CI 31.2-33.4 mmHg]). ROSC occurred in 6/18 (33%) animals in the ITD-CPR, and 14/18 (78%) in the S-CPR group (p = 0.02). Survival occurred in 3/18 (17%) ITD-CPR and 13/18 (72%) S-CPR group (p = 0.003).
ITD-CPR did not improve CPP compared to S-CPR. ROSC and survival were significantly lower with ITD-CPR.
阻抗阈值装置（ITD）旨在通过在胸外按压的放松阶段产生胸内负压来增强心肺复苏期间的循环。
我们试图确定ITD对冠状动脉灌注压（CPP）、自主循环恢复（ROSC）和短期生存率（ROSC后20分钟）的影响。我们假设与标准心肺复苏相比，ITD将改善所有这三个变量。
采用嵌套在随机初级研究中的病例对照设计，我们将使用ITD的心肺复苏（ITD-CPR）与不使用该装置的标准心肺复苏（S-CPR）进行比较。在未治疗的室颤（VF）8分钟后，我们将36头体重23-29千克的家猪（每组18头）系统地分配为接受ITD-CPR或S-CPR复苏。在第8分钟时，开始机械胸外按压和通气，并给予药物（0.1毫克/千克肾上腺素、40单位血管加压素、1.0毫克普萘洛尔、1毫当量/千克碳酸氢钠）。在室颤第11分钟时给予首次抢救电击（150焦耳双相波）。我们记录了CPP、ROSC（收缩压>80毫米汞柱持续60秒）和生存率。数据采用Fisher精确检验和广义估计方程（GEE）进行分析，α=0.05。
我们分析了3150次按压。ITD-CPR组的CPP（28.1毫米汞柱[95%CI 27-29.3毫米汞柱]）与S-CPR组（32.3毫米汞柱[95%CI 31.2-33.4毫米汞柱]）无差异。ITD-CPR组6/18（33%）的动物出现ROSC，S-CPR组为14/18（78%）（p=0.02）。ITD-CPR组3/18（17%）存活下来，S-CPR组为13/18（72%）（p=0.003）。
与S-CPR相比，ITD-CPR并未改善CPP。ITD-CPR的ROSC和生存率显著更低。
