Kill Clemens, Torossian Alexander, Freisburger Christian, Dworok Sebastian, Massmann Martin, Nohl Thorsten, Henning Ronald, Wallot Pascal, Gockel Andreas, Steinfeldt Thorsten, Graf Jürgen, Eberhart Leopold, Wulf Hinnerk
Department of Anaesthesiology and Critical Care, Philipps-University, D-35033 Marburg, Germany.
Resuscitation. 2009 Sep;80(9):1060-5. doi: 10.1016/j.resuscitation.2009.05.015. Epub 2009 Jul 14.
During cardiac arrest the paramount goal of basic life support (BLS) is the oxygenation of vital organs. Current recommendations are to combine chest compressions with ventilation in a fixed ratio of 30:2; however the optimum compression/ventilation ratio is still debatable. In our study we compared four different compression/ventilation ratios and documented their effects on the return of spontaneous circulation (ROSC), gas exchange, cerebral tissue oxygenation and haemodynamics in a pig model.
Study was performed on 32 pigs under general anaesthesia with endotracheal intubation. Arterial and central venous lines were inserted. For continuous cerebral tissue oxygenation a Licox PtiO(2) probe was implanted. After 3 min of cardiac arrest (ventricular fibrillation) animals were randomized to a compression/ventilation-ratio 30:2, 100:5, 100:2 or compressions-only. Subsequently 10 min BLS, Advanced Life Support (ALS) was performed (100%O(2), 3 defibrillations, 1mg adrenaline i.v.). Data were analyzed with 2-factorial ANOVA.
ROSC was achieved in 4/8 (30:2), 5/8 (100:5), 2/8 (100:2) and 0/8 (compr-only) pigs. During BLS, PaCO(2) increased to 55 mm Hg (30:2), 68 mm Hg (100:5; p=0.0001), 66 mm Hg (100:2; p=0.002) and 72 mm Hg (compr-only; p<0.0001). PaO(2) decreased to 58 mmg (30:2), 40 mm Hg (100:5; p=0.15), 43 mm Hg (100:2; p=0.04) and 26 mm Hg (compr-only; p<0.0001). PtiO(2) baseline values were 12.7, 12.0, 11.1 and 10.0 mm Hg and decreased to 8.1 mm Hg (30:2), 4.1 mm Hg (100:5; p=0.08), 4.3 mm Hg (100:2; p=0.04), and 4.5 mm Hg (compr-only; p=0.69).
During BLS, a compression/ventilation-ratio of 100:5 seems to be equivalent to 30:2, while ratios of 100:2 or compressions-only detoriate peripheral arterial oxygenation and reduce the chance for ROSC.
在心脏骤停期间，基础生命支持（BLS）的首要目标是使重要器官获得氧合。目前的建议是将胸外按压与通气按30:2的固定比例结合；然而，最佳的按压/通气比例仍存在争议。在我们的研究中，我们比较了四种不同的按压/通气比例，并记录了它们对猪模型中自主循环恢复（ROSC）、气体交换、脑组织氧合和血流动力学的影响。
对32只气管插管全身麻醉的猪进行研究。插入动脉和中心静脉导管。为了连续监测脑组织氧合，植入了Licox PtiO₂探头。在心脏骤停（室颤）3分钟后，将动物随机分为按压/通气比例为30:2、100:5、100:2或仅按压组。随后进行10分钟的BLS和高级生命支持（ALS）（100%氧气，3次除颤，静脉注射1mg肾上腺素）。数据用双因素方差分析进行分析。
在4/8（30:2）、5/8（100:5）、2/8（100:2）和0/8（仅按压）的猪中实现了ROSC。在BLS期间，PaCO₂分别升至55mmHg（30:2）、68mmHg（100:5；p=0.0001）、66mmHg（100:2；p=0.002）和72mmHg（仅按压；p<0.0001）。PaO₂分别降至58mmHg（30:2）、40mmHg（100:5；p=0.15）、43mmHg（100:2；p=0.04）和26mmHg（仅按压；p<0.0001）。PtiO₂基线值分别为12.7、12.0、11.1和10.0mmHg，分别降至8.1mmHg（30:2）、4.1mmHg（100:5；p=0.08）、4.3mmHg（100:2；p=0.04）和4.5mmHg（仅按压；p=0.69）。
在BLS期间，按压/通气比例为100:5似乎与30:2相当，而100:2或仅按压的比例会使外周动脉氧合恶化并降低ROSC的机会。
