Department of Neonatology, Guangdong Academy of Medical Sciences/Guangdong General Hospital, Guangzhou, Guangdong 510080, China.
Chin Med J (Engl). 2011 Aug;124(15):2284-9.
Echocardiography is regarded as a gold standard for measuring hemodynamic values. The ultrasonic cardiac output monitor (USCOM) is a new method for measuring hemodynamics and could provide non-invasive point of care guidance. So far, there are no published USCOM reference values for neonates, nor has USCOM's accuracy been established in this population. We aimed to determine the accuracy and clinical utility of the USCOM in healthy neonates relative to published echocardiographic data, to establish normal hemodynamic parameters that it measures, and to assess the possible role of USCOM as an alternative to echocardiography as a trend monitor.
Right and left heart hemodynamics of 90 normal neonates were measured during circulatory adaptation over the first three days of life using the USCOM and automated oscillotonometry.
Heart rate showed a significant decline from days one to three, from 126 to 120 (P < 0.001). Systolic, diastolic and mean arterial pressures all increased significantly from 66 to 71 mmHg, 33 to 38 mmHg and 44 to 49 mmHg, respectively (P < 0.001 in each case). Right ventricular cardiac index (RV-CI) showed no change with a mean of 5.07 L × min(-1) × m(-2). Left ventricular cardiac index (LV-CI) declined from 3.43 to 3.00 L × min(-1) × m(-2) (P < 0.001). RV-CI exceeded LV-CI on all three days by a mean of 61%. The systemic vascular resistance index (SVRI), based on LV-CI, increased significantly over the three days from 1083 to 1403 dyne × sec × cm(-5) × m(2) (P < 0.001).
Normal neonatal hemodynamic values, as indicated by USCOM, were established. LV-CI measurement showed excellent agreement with published echocardiographic studies. RV-CI was constant and exceeded LV-CI for all three days of this study. It may be falsely high due to flow velocity measurement errors arising from the pulmonary branch arteries, and may represent a limitation of the USCOM method. The progressive rise of arterial pressure and SVRI despite a declining LV-CI may indicate functional closure of the ductus arteriosus, with the greatest change occurring within the first 24 hours. Evidence of closure of the foramen ovale was not observed.
超声心动图被认为是测量血流动力学值的金标准。超声心输出量监测仪（USCOM）是一种新的测量血流动力学的方法，可以提供非侵入性的即时护理指导。到目前为止，还没有发表过新生儿 USCOM 的参考值，也没有确立 USCOM 在该人群中的准确性。我们旨在确定 USCOM 在健康新生儿中的准确性和临床实用性，相对于已发表的超声心动图数据，确定其测量的正常血流动力学参数，并评估 USCOM 作为超声心动图趋势监测替代方法的可能作用。
使用 USCOM 和自动振荡测量仪，在出生后三天内测量 90 名正常新生儿的右心和左心血流动力学。
心率从第一天到第三天显著下降，从 126 次/分降至 120 次/分（P < 0.001）。收缩压、舒张压和平均动脉压均显著升高，从 66 毫米汞柱升至 71 毫米汞柱，从 33 毫米汞柱升至 38 毫米汞柱，从 44 毫米汞柱升至 49 毫米汞柱（P < 0.001）。右心室心输出量指数（RV-CI）没有变化，平均为 5.07 L × min(-1) × m(-2)。左心室心输出量指数（LV-CI）从 3.43 降至 3.00 L × min(-1) × m(-2)（P < 0.001）。RV-CI 在三天内平均比 LV-CI 高 61%。基于 LV-CI 的全身血管阻力指数（SVRI）在三天内从 1083 增至 1403 达因×秒×厘米(-5)×m(2)（P < 0.001）。
确定了 USCOM 指示的正常新生儿血流动力学值。LV-CI 测量与已发表的超声心动图研究具有极好的一致性。RV-CI 在本研究的三天内保持恒定并超过 LV-CI。它可能由于肺动脉分支的血流速度测量误差而偏高，这可能是 USCOM 方法的局限性。尽管 LV-CI 下降，但动脉压和 SVRI 逐渐升高可能表明动脉导管功能性关闭，最大变化发生在 24 小时内。未观察到卵圆孔关闭的证据。
