Mickell J J, Lucking S E, Chaten F C, Young E S
Department of Pediatrics, Children's Medical Center, Medical College of Virginia, Virginia Commonwealth University, Richmond.
Crit Care Med. 1990 Jun;18(6):645-50.
The NCCOM3-R6 monitor continuously monitors cardiac output and five other cardiovascular variables from the thoracic electrical bioimpedance signal. We averaged data over 5-min intervals for 130 min in 100 control studies in 40 pediatric ICU patients, age 0.04 to 20.39 yr (median 1.39) and weighing 2.0 to 59.5 kg (median 8.8). For individual studies, 99% of the 5-min averages of cardiac output fell within +/- 44% of the baseline cardiac output for that study. Normal ranges were somewhat narrower for the other five variables. When we averaged data for 100 studies, 5-min interval observations for each variable did not deviate from baseline over a 2-h period (p greater than .70). With a sample size of 100 studies, we could detect a change in cardiac output of +/- 5% at the p less than .005 level with a power of 0.95. We conclude that with a sufficiently large sample size, studies employing the NCCOM3 can detect clinically significant cardiovascular changes due to pharmacologic or procedural stressors.
NCCOM3-R6监护仪通过胸段电阻抗信号持续监测心输出量及其他五个心血管变量。在对40名儿科重症监护病房患者（年龄0.04至20.39岁，中位数1.39岁；体重2.0至59.5千克，中位数8.8千克）进行的100项对照研究中，我们对130分钟内每5分钟的间隔数据进行了平均。对于各项研究，心输出量5分钟平均值的99%落在该研究基线心输出量的±44%范围内。其他五个变量的正常范围略窄。当我们对100项研究的数据进行平均时，每个变量在2小时内的5分钟间隔观察值与基线相比无偏差（p>0.70）。以100项研究作为样本量，我们能够在p<0.005水平、检验效能为0.95的情况下检测到±5%的心输出量变化。我们得出结论，在样本量足够大时，采用NCCOM3的研究能够检测出因药物或操作应激源引起的具有临床意义的心血管变化。
