无创心输出量监测在心力衰竭患者循环支持时的应用

背景尽管肺动脉导管（PAC）热稀释法的有效性、安全性均存在问题且使用困难，然而该方法目前在围手术期心外科重症监护室中仍普遍被应用于对中心血流动力学的监测和管理。超声心输出量监测仪（USCOM）是一种无创性连续多普勒装置，用于直接测量心输出量（CO），可替代PAC。虽然USCOM的可靠性存在一些公认的局限性，但已证实该方法比PAC在心外科重症监护室更具主导地位。我们比较了心力衰竭（HF）患者在应用一种原位全人工心脏（TAH）控制治疗期间，USCOM与CardioWest的心输出量测量结果。方法选择安装全人工心脏的心力衰竭（TAHHF）患者，按照盲法使用CardioWest和USCOM设备监测患者心输出量（CO）、每搏心输出量（SV）和心率（HR）。根据CardioWest所控制流量的不同，监测7例患者18个不同时点，获得了508对测量结果。用Bland—Altman分析法比较一致性。结果使用CardioWest和USCOM设备测得患者的心输出量、每搏心输出量和心率的平均值和标准差（±标准差）分别是7．33±0．46和7．34±0．51L/min、56．2±3．8和56．6±3．8ml，以及131±3和130±4bpm。心输出量的范围为5．2，9．3L／min。两种方法检测的心输出量、每搏心输出量和心率的平均差值分别是-0．01±0．23L／min、-0．34±1．97ml和0．9±2．3bpm，平均百分比差为一0．3％、-0．6％和0．7％。心输出量、每搏心输出量和心率一致性的百分比范围分别为6．4％、7．1％和3．6％。结论USCOM对于安装全人工心脏的心力衰竭患者的心输出量无创性监测和管理不失为一个可行且准确的方法，其可能在心血管疾病的诊断和治疗中有更广泛的应用。

BACKGROUND： Pulmonary artery catheter （PAC） thermodilution is commonly used in the perioperative cardiac surgical intensive care unit for measurement and management of central hemodynamics despite questions about effectiveness, difficulty of use, and safety. USCOM is a noninvasive continuous wave Doppler device for direct measurement of cardiac output （CO） and is an alternative to PAC. USCOM validation has predominantly been in the cardiac surgical intensive care unit against PAC, despite the recognized limitations in reliability of the method. We compared USCOM CO measurements with the CardioWest, an orthotopic total artificial heart （TAH）, in heart faiktre （HF） subjects during controlled interventions. METHOD： CO, stroke volume （SV）, and heart rate （HR） were measured in a blinded fashion using the CardioWest and the USCOM device in TAH I-IF patients. Five-hundred eight paired measures from 18 examinations of seven subjects were acquired as flow was varied by the CardioWest controller. Bland-Altman analysis was used to compare agreement. RESULTS： Mean values and standard deviations （ ± SD） for CO, SV, and HR by CardioWest and USCOM were 7. 33 ±0. 46 and 7. 34±0. 51 L/min, 56. 2± 3.8 and 56. 6 ± 3.8 ml, and 131 ± 3 and 130 ± 4 bpm, respectively. CO ranged from 5.2 to 9.3 L/rain. The mean differences between methods for CO, SV, and HR were -0. 01 ± 0. 23 L/min, -0. 34 ±1.97 ml, and 0. 9 ± 2. 3 bpm, respectively, with mean percentage differences of -0. 3%, - 0. 6%, and 0. 7%. The percentage limits of agreement for CO, SV, and HR were 6. 4%, 7. 1%, and 3.6%. DISCUSSION： USCOM is a feasible and accurate method for noninvasive measurement and monitoring of CO in TAH HF patients and may have a wider application in diagnosis and management of cardiovascular disease.