摘要
目的探讨胸外按压对全身血流动力学和氧代谢的影响。方法１３例使用机械通气和血流动力学监测的外科重症监护病房病人，在呼吸心跳停止后继续维持高浓度氧的机械通气，同时进行持续胸外按压（频率８０～１５０次／分）。在此期间，每隔５分钟测量血流动力学指标和动、静脉血气，并计算氧代谢的各项指标。结果（１）心排量在按压开始的１～３分钟内呈先升后降的变化，按压频率在１００～１５０次／分内可获得较高的心排量。（２）所测各处压力不等，心脏灌注压为（４２±５１）／（６±１４）ｍｍＨｇ（平均为１５±２５ｍｍＨｇ）。（３）肺循环阻力大于外周循环阻力，与生理情况相反；右心室功及右室每搏功下降幅度小于左心室功与左室每搏功。（４）氧载为生理的１／４，氧耗为生理的１／２，氧提取率为生理的２～３倍。结论胸外按压在高频率时可能存在频率共振机制，最佳的共振频率可能在１２０～１４０次／分；氧耗与氧载仍存在依赖关系；心肺复苏过程中血流动力学和氧代谢呈不均一性。
Objective To evaluate the hemodynamics and oxygen metabolism during cardiopulmonary resuscitation in human body. Methods Swan Ganz catheter was introduced in 13 critically ill patients, who were supported by ventilator and treated with closed chest cardiac massage (frequency 80～150/min) for 30 minutes. Cardiac output (CO) and arterial and mixed venous blood gas analysis were measured every 5 minutes after cardiac arrest. Results (1) CO increased in the begining and decreased gradually in 1～3 minutes. Higher CO could be obtained with increased compression frequency (100～150/min). (2) Right atrial pressure (RAP), pulmonary arterial pressure (PAP), arterial pressure (AP) and AP RAP (coronary perfusion pressure) varied with the difference between the systolic and diastolic pressure. Coronary perfusion occurred mainly in the phase of pressing, but not relaxing. (3) Higher compression frequency led to better cardiac output because of the improved frequency resonance effect of the chest wall, thoracic cavity, cardiac chambers and large vesseles. (4) Pulmonary vascular resistance (PVR) was higher than systemic vascular resistance (SVR) and the decrement of right ventricular work (RVW) and right ventricular stroke work (RVSW) was less than that of left ventricular work (LVW) and left ventricular stroke work (LVSW). It means that the effect of compression exerts mainly on the pulmonary circulation and right cardiac chambers. (5) Oxygen metabolism study showed that oxygen delivery (O 2) was almost 1/4 of the normal volume, oxygen consumption (O 2) half of the normal, and oxygen extraction ratio 2～3 times of the normal range. O 2 was dependent on O 2. (6) Alveolo arteriolar oxygen tension difference and arterio venous shunt fraction were abnormal. In 3 patients with PaO 2>60 and PaCO 2<50 mmHg, life could be sustained. Conclusion (1) There might be a frequency resonance machanism during high frequency compression. The best frequency was 120～140 beat/min. (2) O 2 in this study was less than the critical limitation and O 2 is dependent on O 2. (3) CO, blood distribution and oxygen metabolism data were not stable in time sequential analysis, though the same effort was provided.
出处
《中华内科杂志》
CAS
CSCD
北大核心
1998年第12期804-807,共4页
Chinese Journal of Internal Medicine
关键词
心肺复苏术
血液动力学
氧代谢
Cardiopulmonary resuscitation Hemodynamics Oxygen
