Evaluation of Pulmonary Function Test by Pneumotachography and Passive Expiratory Flow-volume Technique in Newborns with Respiratory Diseases

Lee, Hye Jin; Kim, Kyung Hyo; Kim, Gyoung Hee

Abstract

PURPOSE
Pulmonary function test is an important diagnostic tool in neonatal intensive care. These tests provide a detailed assessment an infant's pulmonary status that can be used in several ways: to monitor the progression of lung disease, to streamline ventilator management, and to assess the infant's response to new treatments, such as surfactant replacement therapy or bronchodilator. The purpose of this study was to evaluate the pulmonary function test including tidal volume, minute ventilation, respiratory rate, flow-volume curve, respiratory system compliance, and respiratory system resistance in newborns with several respiratory diseases.
METHODS
This study was performed on 101 newborns with respiratory diseases including hyaline membrane disease(HMD), bronchopulmonary dysplasia(BPD), pneumonia, meconium staining, congenital heart disease(CHD) from Febrary, 1994 to Febrary, 1995. Pulmonary function test including tidal volume, % V/PTEF, TEF25/ PTEF, ME/MI, respiratory system compliance, and respiratory system resistance was performed by System 2600 Pediatric Pulmoary Fuction Cart(SensorMedics, CA. USA) using pneumotachography and passive expiratory flow-volume technique.
RESULTS
1) Gestational age, birth weight, and birth height in neonates with HMD or BPD were significantly lower than normal neonates(p<0.05). 2) Respiratory rate in neonates with HMD was significantly higher than normal neonates(p<0.05). Tidal volume in neonates with HMD or BPD was significantly lower than normal neonates(p<0.05). Respiratory rate and tidal volume in neonates with meconium staining, pneumonia, pneumothorax, or CHD were not significantly different from normal neonates(p>0.05). 3) In the results of tidal breathing flow volume loop, % V/PTEF, TEF25/PTEF and ME/MI in neonates with HMD or BPD were significantly lower than normal neonates(p<0.05), but these results in neonates with meconium staining, pneumonia, pneumothorax, or CHD were not significantly different from normal neonates(p>0.05). 4) Respiratory system compliance in neonates with HMD, BPD, or pneumonia was significantly lower than normal neonates, and respiratory system resistance in neonates with HMD, BPD, or pneumonia was significantly higher than normal neonates(p<0.05). Respiratory system compliance and resistance in neonates with meconium staining, pneumothorax, or CHD were not significantly different from normal neonates(p>0.05).
CONCLUSIONS
Pulmonary function tests in neonates with HMD, BPD, or pneumonia showed differnt findings with that in normal neonates, but pulmonary function tests in neonates with meconium staining, pneumothorax, or CHD showed normal findings.