iPFT results
As a group, iPFT results in the SARS-CoV-2 group showed normal lung
volumes, normal lung compliance (Crs) and normal airway resistance (Raw)
(table 2). Expiratory flows in the SARS-CoV-2 group were mildly
decreased, mainly when assessing flows from the tidal expiratory
flow-volume curve (median (IQR)
V̇maxFRC=60 (37-80) %predicted).
When comparing the SARS-CoV-2
group to controls, no differences in tidal breathing measurements, lung
volumes, compliance nor resistance were found. The SARS-CoV-2 group
demonstrated slightly better expiratory flows when compared to the
control, mainly for low lung volumes (median (IQR)
FEF85%=75 (48-98) in the SARS-CoV-2 group Vs.
FEF85%=58 (43-77) in controls, p=0.035) (table 2).
Categorization according to iPFT pattern and bronchodilator
responsiveness, showed no significant difference between the SARS-CoV-2
group and the controls, neither in the occurrence of different iPFT
patterns, nor in the iPFT results (table 3). The majority of infants
tested in both groups demonstrated an obstructive iPFT pattern (63% of
the SARS-CoV-2 group and 66% of the controls, p=0.776) and only a
minority showed normal iPFT results (31% of the SARS-CoV-2 group and
15% of the controls, p=0.074). Infants in the SARS-CoV-2 group with an
obstructive lung disease pattern had similar iPFT results to controls.
Assessment of bronchodilator responsiveness (BDR) was available in 335
infants from our cohort (7 from the SARS-CoV-2 group and 328 controls).
A positive BDR was present in 21% of the SARS-CoV-2 group and 22% of
controls (p=0.904), see table 3.
In the SARS-CoV-2 group, abnormal pulmonary function tests were not
associated with a personal or familial history of atopy nor with
exposure to second-hand smoke. Data regarding atopy and second-hand
smoke exposure were not sufficiently available for the control group.