Pulmonary Function Testing in Healthy Infants in Rural Bangladesh: Feasibility Study.

Background: Infant pulmonary function testing (iPFT) in low- and middle-income countries is limited. We evaluated the early feasibility of iPFT in rural Bangladesh.

Methods: Experts established an iPFT laboratory at Zakiganj Upazila Health Complex in Sylhet, Bangladesh and trained staff. Infants ≤ 6 months old participating in a cohort study between 2021 and 2022 were eligible for respiratory oscillometry (Osc), tidal breath flow-volume loops (TBFVL), and sulphur hexaflouride multiple breath washout (MBW) during natural sleep. Participants with a respiratory infection within 4 weeks were not tested. Among the first 25 infants with attempted Osc, TBFVL, or MBW measurements, we report the test proportions meeting international quality standards, measurement averages, and the mean measurement differences between laboratory staff and experts.

Results: Among the first 25 eligible infants with attempted measurements, acceptable Osc measurements were achieved in 88% (22/25), TBFVL in 96% (24/25), and MBW in 88% (22/25). Infants tested by Osc at 2 months were a median (IQR) of 81 days old (73, 85) and tested at 6 months were a median of 194 days old (193, 202); TBFVL/MBW tested infants were a mean 83 days (79, 87). Mean (SD) Osc resistance at 7 Hz was 66.3 (25.2) and 64.0 (22.4) hPa.s.L at 2 and 6 months. At 2 months, TBFVL mean tidal volume/body weight was 7.4 (1.4) mL/kg and MBW mean (SD) lung clearance index was 7.2 (1.0) turnovers. iPFT staff and expert interpretation differences were minimal.

Conclusions: Establishing an iPFT laboratory and performing quality measurements and expert-level interpretations in rural Bangladesh is feasible.