Lødrup Carlsen K C, Stenzler A, Carlsen K H
Department of Paediatrics, Ullevål Hospital, Oslo, Norway.
Pediatr Pulmonol. 1997 Dec;24(6):391-6. doi: 10.1002/(sici)1099-0496(199712)24:6<391::aid-ppul3>3.0.co;2-k.
The tidal flow volume (TFV) loop ratios of (1) time to peak flow (tPTEF) to total expiratory time (tE) [tPTEF/tE] and (2) volume to peak flow (VPTEF) to expired volume (VE) [VPTEF/VE] are reported to decrease with age in early life, and to decrease in subjects with obstructive airways disease (OAD). However, the mechanisms behind these changes are not well known. Thus, we reanalyzed data from 24 healthy neonates (mean birthweight: 3.49 kg +/- 0.42 kg (SD)), 26 presently asymptomatic asthmatic children (age: 33 +/- 21 months), and 26 controls (age: 34 +/- 19 months) to elucidate what is responsible for the changes in these ratios in health and disease. Lung function was measured by TFV loops (SensorMedics 2600) at 1 hour of life and on the following day in the neonates, and before and after inhaled nebulized salbutamol (0.05 mg/kg) in the asthmatics and their controls. The observed decreases in mean tPTEF/tE and VPTEF/VE from 1 hour to 1 day of life (neonates) were entirely due to increased tE and VE, respectively secondary to a decrease in respiratory rate (P = 0.03). In asthmatics (young children), the decreased baseline tPTEF/tE and VPTEF/VE were due to lower tPTEF and VPTEF, with no significant differences in tE and VE in asthmatics and controls. The improved ratios in asthmatic children following inhalation of a bronchodilator were mainly due to increased tPTEF and VPTEF. Our observations point out the importance of evaluating both tPTEF and either tPTEF/tE or VPTEF/VE when attempting to differentiate between changes in ratios that are related to age versus changes that reflect underlying obstructive airways disease.
据报道，（1）呼气流量峰值时间（tPTEF）与总呼气时间（tE）的比值[tPTEF/tE]以及（2）呼气流量峰值容积（VPTEF）与呼出容积（VE）的比值[VPTEF/VE]，在生命早期会随着年龄增长而降低，在患有阻塞性气道疾病（OAD）的受试者中也会降低。然而，这些变化背后的机制尚不清楚。因此，我们重新分析了24名健康新生儿（平均出生体重：3.49 kg±0.42 kg（标准差））、26名目前无症状的哮喘儿童（年龄：33±21个月）和26名对照儿童（年龄：34±19个月）的数据，以阐明在健康和疾病状态下这些比值变化的原因。通过潮气流量容积（TFV）环（SensorMedics 2600）在新生儿出生后1小时及次日测量肺功能，在哮喘儿童及其对照儿童吸入雾化沙丁胺醇（0.05 mg/kg）前后测量肺功能。在新生儿中，观察到从出生后1小时到1天，平均tPTEF/tE和VPTEF/VE降低，这完全是由于tE和VE增加，分别继发于呼吸频率降低（P = 0.03）。在哮喘儿童（幼儿）中，基线tPTEF/tE和VPTEF/VE降低是由于tPTEF和VPTEF较低，哮喘儿童和对照儿童的tE和VE无显著差异。哮喘儿童吸入支气管扩张剂后比值改善主要是由于tPTEF和VPTEF增加。我们的观察结果指出，在试图区分与年龄相关的比值变化和反映潜在阻塞性气道疾病的变化时，评估tPTEF以及tPTEF/tE或VPTEF/VE的重要性。
