Division of Neonatology, Department of Pediatrics, McGill University, Montreal, Que., Canada.
Neonatology. 2013;104(1):42-8. doi: 10.1159/000347101. Epub 2013 May 24.
Mechanical ventilation (MV) is associated with changes in autonomic nervous system activity in preterm infants, which can be assessed by measurements of heart rate variability (HRV). Decreased HRV has been described in adults undergoing disconnection from MV; such information is not available in preterm infants.
To compare differences in HRV between infants successfully extubated and those who failed, and to evaluate the accuracy of HRV as a predictor of extubation readiness.
This is a prospective, observational study of infants with a birth weight ≤1,250 g undergoing their first extubation attempt. Heart rate was measured during a 60-min period immediately prior to extubation and HRV was calculated using the frequency domain analysis.
A total of 47 infants were studied; 36 were successfully extubated and 11 reintubated. There were no differences in patient demographics, ventilator settings, blood gases or postextubation management between the groups. All components of the HRV analysis were significantly decreased in infants who failed, generating high areas under the receiver operating characteristic curve. The specificity and positive predictive values were 100, but with limited sensitivity and negative predictive values.
Infants considered 'ready to be extubated' but who subsequently failed their first extubation attempt had decreased HRV prior to extubation. Though promising, the value of HRV as a predictor of extubation readiness requires further evaluation.
机械通气（MV）会改变早产儿自主神经系统的活动，可以通过心率变异性（HRV）的测量来评估。在与 MV 断开连接的成年人中已经描述了 HRV 的降低；但早产儿中没有此类信息。
比较成功拔管和失败拔管的婴儿之间 HRV 的差异，并评估 HRV 作为拔管准备预测指标的准确性。
这是一项对出生体重≤1250g 的首次尝试拔管的婴儿进行的前瞻性、观察性研究。在拔管前 60 分钟内测量心率，并使用频域分析计算 HRV。
共研究了 47 名婴儿；36 名成功拔管，11 名重新插管。两组患者的人口统计学、呼吸机设置、血气或拔管后管理均无差异。所有 HRV 分析成分在失败的婴儿中均显著降低，产生了高的受试者工作特征曲线下面积。特异性和阳性预测值均为 100，但敏感性和阴性预测值有限。
被认为“准备好拔管”但随后首次拔管失败的婴儿在拔管前 HRV 降低。尽管有希望，但 HRV 作为拔管准备预测指标的价值需要进一步评估。
