Ulm Lara N, Hamvas Aaron, Ferkol Thomas W, Rodriguez Oscar M, Cleveland Claudia M, Linneman Laura A, Hoffmann Julie A, Sicard-Su Maria J, Kemp James S
1 Department of Pediatrics, Division of Newborn Medicine.
Ann Am Thorac Soc. 2014 Jun;11(5):753-60. doi: 10.1513/AnnalsATS.201310-363OC.
Better phenotypic descriptions are needed for chronic lung disease among surviving premature infants.
The purpose of this study was to evaluate the potential usefulness of respiratory inductance plethysmography in characterizing respiratory system mechanics in preterm infants at 32 weeks postmenstrual age.
Respiratory inductance plethysmography was used to obtain the phase angle, Φ, to describe rib cage and abdominal dyssynchrony in 65 infants born between 23 and 28 weeks gestation, all of whom were studied at 32 weeks postmenstrual age. Up to 60 breaths were evaluated for each subject. Sources of intrasubject variability in Φ arising from our methods were explored using mechanical models and by evaluating interobserver agreement.
The mean Φ from infants ranged from 5.8-162.9°, with intrasubject coefficients of variation ranging from 11-123%. On the basis of the mechanical model studies, respiratory inductance plethysmography recording and analysis software added <2.3% to the intrasubject variability in Φ. Potential inconsistencies in breaths selected could have contributed 8.1%, on average, to the total variability. The recording sessions captured 22.8 ± 9.1 minutes of quiet sleep, and enough breaths were counted to adequately characterize the range of Φ in the session.
Φ is quite variable during even short recording sessions among preterm infants sleeping quietly. The intrasubject variability described herein arises from the instability of the rib cage and abdominal phase relationship, not from the recording and analytical methods used. Despite the variability, Φ measurements allowed the majority (80%) of infants to be reliably categorized as having relatively synchronous or dyssynchronous breathing. Respiratory inductance plethysmography is easy to use and should prove useful in quantifying respiratory mechanics in multicenter studies of preterm infants.
对于存活的早产儿慢性肺病，需要更好的表型描述。
本研究的目的是评估呼吸感应体积描记法在确定孕龄32周早产儿呼吸系统力学特征方面的潜在用途。
采用呼吸感应体积描记法获取相角Φ，以描述65例孕23至28周出生的婴儿的胸廓和腹部不同步情况，所有婴儿均在孕龄32周时进行研究。对每个受试者评估多达60次呼吸。使用力学模型并通过评估观察者间的一致性，探讨了我们的方法引起的受试者内Φ变异性的来源。
婴儿的平均Φ范围为5.8 - 162.9°，受试者内变异系数范围为11 - 123%。基于力学模型研究，呼吸感应体积描记法记录和分析软件使受试者内Φ变异性增加<2.3%。所选呼吸的潜在不一致平均可能导致总变异性的8.1%。记录时段捕捉到22.8±9.1分钟的安静睡眠，并且计数了足够的呼吸次数以充分表征该时段内Φ的范围。
即使在早产儿安静睡眠的短记录时段内，Φ也有很大变化。本文所述的受试者内变异性源于胸廓和腹部相位关系的不稳定性，而非所用的记录和分析方法。尽管存在变异性，但Φ测量使大多数（80%）婴儿能够可靠地分类为具有相对同步或不同步呼吸。呼吸感应体积描记法易于使用，应证明在早产儿多中心研究中量化呼吸力学方面有用。
