Filippone M, Narne S, Pettenazzo A, Zacchello F, Baraldi E
Department of Pediatrics, University of Padua, Padua, Italy.
Am J Respir Crit Care Med. 2000 Nov;162(5):1795-800. doi: 10.1164/ajrccm.162.5.9912008.
Flow-volume loop evaluation yields considerable diagnostic information about adult patients with upper airway obstruction. No conclusive data support the reliability of this method in young children with noisy breathing. We used analysis of flow-volume loops at tidal breathing (TB-FV) as a first diagnostic approach to young children presenting with persistent noisy breathing (chronic stridor and/or wheezing). Flexible fiberoptic bronchoscopy was performed to establish a conclusive diagnosis and was used to verify the accuracy of the preliminary functional localization of the airway obstruction causing noisy breathing. The physician conducting pneumotachography was blinded to the bronchoscopic findings in the study, and the investigators conducting bronchoscopy were blinded to the pneumotachographic findings. Through a 6-yr period, 113 consecutive young children (ranging in age from 15 to 48 mo) with noisy breathing were enrolled in the study. Three morphologically abnormal TB-FV patterns, as compared with the normal round-shaped TB-FV loops obtained with 15 healthy children, were identified in 110 patients. A TB-FV pattern of inspiratory fluttering was found in 26 subjects and in the first 3 yr of the study was always associated with an endoscopic diagnosis of isolated laryngomalacia. Subsequently, this pattern was used to diagnose isolated laryngomalacia in 18 other infants, in whom endoscopy was avoided. Of infants with endoscopic evidence of airway obstruction ranging from the glottis to the mainstem bronchi (49 subjects), all but three showed a TB-FV loop pattern characterized by expiratory-limb flattening. A concave expiratory loop, with early expiratory peak flow and low flow at low volume, was invariably associated with peripheral bronchoconstriction, without endoscopic evidence of anatomic abnormalities (20 cases). In conclusion, TB- FV loop analysis is a noninvasive, accurate method of establishing the site of airway obstruction in young children with recurrent stridor and/or wheezing. Clinical use of this method may provide interesting pathophysiologic information and may be useful in addressing the diagnostic management of such children.
流量-容积环评估可为患有上气道阻塞的成年患者提供大量诊断信息。但尚无确凿数据支持该方法在呼吸有杂音的幼儿中的可靠性。我们将潮气呼吸时的流量-容积环分析（TB-FV）作为对持续呼吸有杂音（慢性喘鸣和/或喘息）的幼儿的首要诊断方法。进行了可弯曲纤维支气管镜检查以确立最终诊断，并用于验证导致呼吸有杂音的气道阻塞初步功能定位的准确性。在该研究中，进行流速描记的医生对支气管镜检查结果不知情，而进行支气管镜检查的研究人员对流速描记结果不知情。在6年期间，连续纳入了113名呼吸有杂音的幼儿（年龄在15至48个月之间）。与15名健康儿童获得的正常圆形TB-FV环相比，在110名患者中识别出三种形态异常的TB-FV模式。在26名受试者中发现了吸气扑动的TB-FV模式，并且在研究的前3年中，该模式始终与孤立性喉软化的内镜诊断相关。随后，该模式被用于诊断另外18名婴儿的孤立性喉软化，这些婴儿避免了内镜检查。在有从声门到主支气管气道阻塞内镜证据的婴儿（49名受试者）中，除3名外，所有婴儿均表现出以呼气肢变平为特征的TB-FV环模式。呼气环凹陷，早期呼气峰值流量和低容积时低流量，总是与外周支气管收缩相关，且无解剖学异常的内镜证据（20例）。总之，TB-FV环分析是一种无创、准确的方法，可用于确定反复喘鸣和/或喘息幼儿的气道阻塞部位。该方法的临床应用可能会提供有趣的病理生理信息，并且可能有助于处理此类儿童的诊断管理。
