行人工膝关节置换术的老年患者全身麻醉中无创连续心排血量监测的安全性研究

Evaluation of continuous non-invasive cardiac output system in elderly patients of knee replacement surgery undergoing general anesthesia

目的 探讨部分二氧化碳重吸收方法 连续测定心排血量（NICO）技术应用在人工膝关节置换手术的老年患者全身麻醉期间监测的可行性和安全性.方法 选择人工膝关节置换手术的老年患者30例,常规施行气管内插管静脉全身麻醉.麻醉全程将NICO传感器连接在气管导管上行连续心排血量监测,在麻醉前、麻醉诱导后30 min、人工膝关节置换术中1 h、2 h和麻醉结束前测定患者心排血量（CO）、心指数（CI）和每搏输出量（SV）;测定血气分析动脉血氧分压（PaO2）和动脉二氧化碳分压（PaCO2）指标.结果 全身麻醉后本组患者CO、CI和SV均明显下降,CO降幅达58.4%;在手术期间CO都在3.4～3.7范围,与麻醉前比较差异有统计学意义（P〈0.01）,而MAP和HR值与麻醉前比较差异无统计学意义（P〉0.05）.麻醉手术中,患者血气分析指标维持正常：PaO2在133.3～150.3 mm Hg范围内,PaCO2在38.9～40.1 mm Hg范围内.结论 老年患者在接受人工膝关节置换术中血流动力学波动明显,麻醉手术中心排血量明显下降,有必要作心排血量监测,保证术程安全;NICO技术连续测定患者心排血量可实时提供血流动力学参数,指导临床维持血压、心率稳定,作为CO监测的有效手段;无创连续NICO监测CO不会造成二氧化碳积蓄,是较安全的监测方法 .

Objective To investigate the feasibility and safety of continuous non-invasive cardiac output （NICO） monitoring via partial carbon dioxide reabsorption technique during general anesthesia in artificial knee joint replacement of elderly patients. Methods Thirty elderly artificial knee joint replacement patients were under intravenous general anesthesia with endotracheal intubation. Cardiac output （CO） , cardiac index （CI） and stroke volume （SV） were measured by the NICO monitor. PaO2 and PaCO2 were detected with blood gas analysis at following time point： 30 rain before anesthesia, 30 min after induction of anesthesia, 1st and 2nd hour ~turing artificial knee joint replacement, and before anesthesia termination. Results After induction of anesthesia, CO, CI and SV were decreased significantly and CO was decreased of 58.4% compared with pre-anesthesia. CO reduced more in the range of 3.4 to 3.7 in anesthesia and surgery than in pre-anesthesia （P 〈 0. 01 ）, while there was not significant difference between anesthesia and pre-anesthesia in MAP and HR （P 〉 0. 05 ）. PaO2 （ 133.3 - 150. 3 mm Hg） and PaCO2 （38.9 -40. 1 mm Hg） in blood gas analysis showed the values were within normal range during anesthesia. Conclusions NICO should be an effective monitoring method of CO in artificial knee joint replacement of elderly patients whose cardiac output have been obviously restrained under general anesthesia. The continuous NICO monitoring would not cause CO2 accumulation. Our study demonstrats that NICO is a safe method of monitoring.