Salcido David D, Koller Allison C, Genbrugge Cornelia, Gumucio Jorge A, Menegazzi James J
University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania.
Emergency Department, University Hospitals Saint-Luc, Brussels, Belgium.
Prehosp Emerg Care. 2024 Oct 24:1-7. doi: 10.1080/10903127.2024.2414391.
Current guidelines for parameters of the delivery of chest compressions (CC) for infants and children are largely consensus based. Of the two recommended depth targets - 1.5 inches and 1/3 anterior-posterior chest diameter (APD) - it is unclear whether these have equal potential for injury. In previous experiments, our group showed in an animal model of pediatric asphyxial out-of-hospital cardiac arrest (OHCA; modeling ∼ 7 year-old children) that 1/3 APD resulted in significantly deeper CC and a higher likelihood of life-threatening injury. We sought to examine and compare injury characteristics of CC delivered at 1.5 inches or 1/3 APD in an infant model of asphyxial OHCA.
Swine were sedated, anesthetized, paralyzed, intubated through direct laryngoscopy, and then mechanically ventilated (10 ml/kg, FiO2:21%). APD was measured and confirmed by two investigators a sliding T-square at the xiphoid. After instrumentation for vital signs monitoring, and while still anesthetized, the endotracheal tube was manually occluded to induce asphyxia, and occlusion was maintained for 9 min. Animals were then randomized to receive CC with a depth of 1.5 inches (Group 1) or 1/3 APD (Group 2), both with a rate of 100 per minute. Advanced life support drugs were administered at 13 min, and defibrillation at 14 min. Resuscitation continued until return of spontaneous circulation (ROSC) or 20 min of failed resuscitation. Survivors were sacrificed with KCl after 20 min of observation. Veterinary staff conducted necropsy to assay lung injury, rib fracture, hemothorax, airway bleeding, great vessel dissection, and heart/liver/spleen contusion. Injury characteristics were summarized and compared Chi-Squared test or Mann-Whitney U-test using an alpha = 0.05.
A total of 36 animals were included for analysis (Group 1: 18; Group 2: 18). Mean (SD) APD overall was 5.58 (0.23) inches, yielding a mean 1/3 APD depth of 1.86 inches. APD did not differ between groups. ROSC rates did not differ between groups. No injury characteristics differed significantly between groups.
In an swine model of infant asphyxial OHCA and resuscitation considering 1/3 APD or 1.5 inches, neither CC depth strategy was associated with increased injury.
目前关于婴儿和儿童胸外按压（CC）实施参数的指南主要基于共识。在两个推荐的按压深度目标——1.5英寸和胸廓前后径（APD）的1/3——中，尚不清楚它们导致损伤的可能性是否相同。在先前的实验中，我们团队在小儿窒息性院外心脏骤停（OHCA；模拟约7岁儿童）的动物模型中发现，APD的1/3会导致显著更深的胸外按压以及更高的危及生命损伤的可能性。我们试图在窒息性OHCA的婴儿模型中检查和比较以1.5英寸或APD的1/3进行胸外按压的损伤特征。
猪经镇静、麻醉、麻痹，通过直接喉镜插管，然后进行机械通气（10ml/kg，FiO2：21%）。两名研究人员用一个滑动直角尺在剑突处测量并确认APD。在安装生命体征监测仪器后，且仍处于麻醉状态时，手动阻塞气管导管以诱导窒息，并维持阻塞9分钟。然后将动物随机分为接受深度为1.5英寸的胸外按压组（第1组）或APD的1/3深度组（第2组），两者的按压速率均为每分钟100次。在13分钟时给予高级生命支持药物，在14分钟时进行除颤。复苏持续到自主循环恢复（ROSC）或复苏失败20分钟。幸存者在观察20分钟后用氯化钾处死。兽医工作人员进行尸检以检测肺损伤、肋骨骨折、血胸、气道出血、大血管夹层以及心脏/肝脏/脾脏挫伤。总结并比较损伤特征，采用卡方检验或曼-惠特尼U检验，α = 0.05。
总共36只动物纳入分析（第1组：18只；第2组：18只）。总体平均（标准差）APD为5.58（0.23）英寸，得出平均APD的1/3深度为1.86英寸。两组之间的APD无差异。两组之间的ROSC率无差异。两组之间的损伤特征无显著差异。
在婴儿窒息性OHCA和复苏的猪模型中，考虑APD的1/3或1.5英寸，两种胸外按压深度策略均未导致损伤增加。
