PDF(Pubmed)
Abstract：
Objective.Cardiac Index (CI) is a key physiologic parameter to ensure end organ perfusion in the pediatric intensive care unit (PICU). Determination of CI requires invasive cardiac measurements and is not routinely done at the PICU bedside. To date, there is no gold standard non-invasive means to determine CI. This study aims to use a novel non-invasive methodology, based on routine continuous physiologic data, called Pulse Arrival Time (PAT) as a surrogate for CI in patients with normal Ejection Fraction (EF).Approach.Electrocardiogram (ECG) and photoplethysmogram (PPG) signals were collected from beside monitors at a sampling frequency of 250 samples per second. Continuous PAT, derived from the ECG and PPG waveforms was averaged per patient. Pearson\'s correlation coefficient was calculated between PAT and CI, PAT and heart rate (HR), and PAT and EF.Main Results.Twenty patients underwent right heart cardiac catheterization. The mean age of patients was 11.7 ± 5.4 years old, ranging from 11 months old to 19 years old, the median age was 13.4 years old. HR in this cohort was 93.8 ± 17.0 beats per minute. The average EF was 54.4 ± 9.6%. The average CI was 3.51 ± 0.72 l min-1m-2, with ranging from 2.6 to 4.77 l min-1m-2. The average PAT was 0.31 ± 0.12 s. Pearson correlation analysis showed a positive correlation between PAT and CI (0.57,p< 0.01). Pearson correlation between HR and CI, and correlation between EF and CI was 0.22 (p= 0.35) and 0.03 (p= 0.23) respectively. The correlation between PAT, when indexed by HR (i.e. PAT × HR), and CI minimally improved to 0.58 (p< 0.01).Significance.This pilot study demonstrates that PAT may serve as a valuable surrogate marker for CI at the bedside, as a non-invasive and continuous modality in the PICU. The use of PAT in clinical practice remains to be thoroughly investigated.
摘要：
目的：心脏指数（CI）是确保儿科重症监护病房（PICU）最终器官灌注的关键生理参数。CI的确定需要进行有创心脏测量，并且通常不在PICU床边进行。迄今为止,没有黄金标准的非侵入性手段来确定CI。这项研究旨在使用一种新的非侵入性方法，基于常规的连续生理数据，称为脉搏到达时间（PAT）作为正常射血分数患者的替代指标。
方法:以每秒250个样本的采样频率从监视器旁边收集心电图(ECG)和光电血管容积图(PPG)信号。连续PAT,根据ECG和PPG波形对每位患者进行平均.计算PAT和CI、PAT和心率(HR)之间的Pearson相关系数，和PAT和射血分数（EF）。主要结果：20例患者接受了右心导管检查。患者平均年龄为11.7±5.4岁,从11个月到19岁不等，中位年龄为13.4岁.该队列中的HR为每分钟93.8±17.0次。平均EF为54.4±9.6％。平均CI为3.51±0.72L/min/m2，范围为2.6至4.77L/min/m2。平均PAT为0.31±0.12秒。Pearson相关分析显示PAT与CI呈正相关(0.57,p<0.01)。HR和CI之间的Pearson相关性以及EF和CI之间的相关性分别为0.22（p=0.35）和0.03（p=0.23）。PAT之间的相关性，当按HR(即PAT×HR)索引时，和CI最低改善至0.58(p<0.01)。＆＃xD;意义：这项初步研究表明，PAT可以作为床边CI的有价值的替代标记，作为PICU中的非侵入性和连续模式。PAT在临床实践中的使用仍有待彻底研究。
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