Gazmuri R J, von Planta M, Weil M H, Rackow E C
Department of Medicine, University of Health Sciences, Chicago Medical School, Illinois 60064.
J Am Coll Cardiol. 1990 Feb;15(2):482-90. doi: 10.1016/s0735-1097(10)80080-4.
Recent studies have demonstrated an increase in carbon dioxide (CO2) tension (PCO2) in both mixed venous and coronary vein blood early in the course of cardiac arrest and cardiopulmonary resuscitation. Because increased PCO2 in the myocardium correlates with both ischemic injury and depression of contractile function, the effects of hypertonic solutions of either the CO2-"generating" sodium bicarbonate (NaHCO3) buffer, a mixture of sodium carbonate (Na2CO3) and sodium bicarbonate (carbicarb) acting as a CO2-"consuming" buffer, or saline placebo (NaCl) were compared during cardiopulmonary resuscitation in 25 healthy minipigs. Both buffer agents significantly increased the pH and HCO3- of arterial, mixed venous and coronary vein blood. Bicarbonate increased whereas carbicarb reduced blood PCO2 in the systemic circuit as anticipated. However, neither the PCO2 nor the lactate content of coronary vein blood was favorably altered by buffer therapy. Four of eight animals treated with bicarbonate, five of eight treated with carbicarb and six of nine placebo-treated animals were successfully resuscitated and had a comparable 24 h survival rate. Coronary perfusion pressure during precordial compression, a critical determinant of resuscitability, was transiently decreased by each of the hypertonic solutions. Accordingly, neither CO2-generating nor CO2-consuming buffers mitigated increases in coronary vein PCO2 or improved the outcome of cardiopulmonary resuscitation under these experimental conditions.
最近的研究表明，在心脏骤停和心肺复苏过程早期，混合静脉血和冠状静脉血中的二氧化碳（CO₂）张力（PCO₂）均有所升高。由于心肌中PCO₂升高与缺血性损伤及收缩功能抑制均相关，因此在25只健康小型猪的心肺复苏过程中，比较了“产生”CO₂的碳酸氢钠（NaHCO₃）缓冲液、作为“消耗”CO₂缓冲液的碳酸钠（Na₂CO₃）和碳酸氢钠混合物（卡比卡）的高渗溶液，以及生理盐水安慰剂（NaCl）的效果。两种缓冲剂均显著提高了动脉血、混合静脉血和冠状静脉血的pH值和HCO₃⁻。正如预期的那样，碳酸氢钠使全身循环中的血液PCO₂升高，而卡比卡使其降低。然而，缓冲液治疗并未使冠状静脉血的PCO₂或乳酸含量得到有利改变。接受碳酸氢钠治疗的8只动物中有4只、接受卡比卡治疗的8只中有5只、接受安慰剂治疗的9只中有6只成功复苏，且24小时生存率相当。心前区按压期间的冠状动脉灌注压是复苏能力的关键决定因素，每种高渗溶液均使其短暂降低。因此，在这些实验条件下，无论是产生CO₂的缓冲液还是消耗CO₂的缓冲液，均未减轻冠状静脉PCO₂的升高，也未改善心肺复苏的结果。
