Normative Data of Infant Pulmonary Function Testing: A Prospective Birth Cohort Study from India

ABSTRACT

Objective: To develop a normal reference range of Infantpulmonary function test (IPFT) indices for Indian children.Design: Prospective birth cohort study.Setting: Division of Pediatric Pulmonology of a tertiary-careinstitute in India from August 2012 to March 2017.Participants: All neonates born at the institute during the studyperiod were screened for eligibility.Measurement IPFT at baseline and every 6-month until 36-months of age.Main Outcome Measure(s) Tidal breathing flow-volume loop(TBFVL), Rapid thoracoabdominal compression (RTC), andRaised volume RTC (RVRTC) indices at baseline and follow-up.Results: 310 newborns were enrolled in the cohort; 281 of them(169 male) had completed 36-months of follow-up at the end ofthe study period. There was no influence of gender on thebaseline IPFT indices. Tidal volume per unit body weight (VT/kg)significantly increased from baseline to 36 months of age(P<0.001) while the peak ratio (tPTEF/tE) initially decreased in first18-months of age (P<0.001), after that returned to the baselinevalue by 36 months of age. RTC indices did not changesignificantly from baseline values. In RVRTC, the ratio of forcedexpiratory volume in 0.5s to forced vital capacity (FEV0.5/FVC)was significantly decreased from baseline to 36 months of age(P=0.002).Conclusions: Normal values for various IPFT indices for TBFVL,RTC, and RVRTC from neonates to the age of 36-month areprovided. These data may be used as normative data for healthyneonates and children of Indian origin