Li Jia, Zhang Gencheng, Holtby Helen, Humpl Tilman, Caldarone Christopher A, Van Arsdell Glen S, Redington Andrew N
Cardiac Program, the Hospital for Sick Children, Toronto, Ontario, Canada.
J Am Coll Cardiol. 2006 Nov 7;48(9):1859-64. doi: 10.1016/j.jacc.2006.07.038. Epub 2006 Oct 17.
The purpose of this study was to evaluate the effects of dopamine on hemodynamic status and oxygen transport in neonates after the Norwood procedure.
Dopamine is widely used to augment cardiac performance and increase oxygen delivery (DO2) in patients after cardiopulmonary bypass (CPB). This might be at the expense of increased myocardial and systemic oxygen consumption (VO2), thus offsetting the improved DO2. This balance is particularly fragile in critically ill neonates.
Systemic oxygen consumption was continuously measured with respiratory mass spectrometry in 13 sedated, paralyzed, and mechanically ventilated neonates for 72 h after the Norwood procedure. Arterial, superior vena caval, and pulmonary venous blood gases were measured to calculate pulmonary blood flow (Q(p)) and systemic blood flow (Q(s)), DO2, and oxygen extraction ratio (ERO2). Rate-pressure product was calculated. Dopamine at a dose of 5 microg/kg/min was routinely administered at cessation of CPB and terminated within the first 48 h. Hemodynamic and oxygen transport measures were obtained before and at 100 min after the termination of dopamine.
Terminating dopamine was not associated with significant changes in arterial pressure, Q(p), Q(s), or DO2 but was associated with a significant decrease in heart rate (p = 0.003), rate-pressure product (p = 0.03), and VO2 (-20 +/- 11%, p < 0.0001), resulting in a significant decrease in ERO2 (p = 0.01).
Dopamine induces a significant increase in VO2 in neonates after the Norwood procedure, and termination is associated with an improved balance of VO2-DO2. These data further emphasize the importance of understanding changes in VO2 as well as DO2 in infants after cardiac surgery.
本研究旨在评估多巴胺对诺伍德手术后新生儿血流动力学状态和氧输送的影响。
多巴胺广泛用于增强体外循环（CPB）后患者的心脏功能并增加氧输送（DO2）。这可能是以增加心肌和全身氧消耗（VO2）为代价的，从而抵消了DO2的改善。这种平衡在危重新生儿中尤为脆弱。
对13例在诺伍德手术后接受镇静、麻痹和机械通气的新生儿，使用呼吸质谱仪连续72小时测量全身氧消耗。测量动脉、上腔静脉和肺静脉血气，以计算肺血流量（Q(p)）、体循环血流量（Q(s)）、DO2和氧摄取率（ERO2）。计算心率-血压乘积。在CPB结束时常规给予5微克/千克/分钟剂量的多巴胺，并在最初48小时内停药。在多巴胺停药前和停药后100分钟获取血流动力学和氧输送指标。
停用多巴胺与动脉压、Q(p)、Q(s)或DO2的显著变化无关，但与心率显著降低（p = 0.003）、心率-血压乘积（p = 0.03）和VO2（-20±11%，p < 0.0001）显著降低有关，导致ERO2显著降低（p = 0.01）。
多巴胺可使诺伍德手术后新生儿的VO2显著增加，停药与VO2-DO2平衡改善有关。这些数据进一步强调了了解心脏手术后婴儿VO2以及DO2变化的重要性。
