[Characteristics of pulmonary function in infants and young children with pertussis-like coughing]

To study the characteristics of pulmonary function in children with pertussis-like coughing caused by different pathogen infections.

The data on etiology and tidal breathing pulmonary function were collected from 95 hospitalized infants and young children with pertussis-like coughing. The tidal breathing pulmonary function was compared between these children and 67 healthy children. According to the type of pathogen, the children with pertussis-like coughing were classified to 6 groups: pertussis (n=17), viral infection (n=23), tuberculosis infection (n=6), Mycoplasma infection (n=9), other bacterial infection (n=8), and unknown pathogen (n=32).

Among the 95 children with pertussis-like coughing, 15 (16%) had mild obstructive ventilatory dysfunction, 30 (32%) had moderate obstructive ventilatory dysfunction, and 22 (23%) had severe obstructive ventilatory dysfunction. Compared with the normal control group, the children with pertussis-like coughing had significant reductions in inspiratory-to-expiratory time ratio, ratio of time to peak tidal expiratory flow to total expiratory time (tPF%tE), and ratio of volume to peak tidal expiratory flow to total expiratory volume (vPF%vE) (P<0.05). The tuberculosis infection and Mycoplasma infection groups had a significantly lower tidal volume than the normal control group (P<0.05). All pathogen infection groups except the tuberculosis infection group had significantly lower tPF%tE and vPF%vE than the normal control group (P<0.05). The pertussis group had significantly lower tPF%tE and vPF%vE than the other infection groups (P<0.05).

Most of children with pertussis-like coughing have abnormal pulmonary functions. The children with Bordetella pertussis infection have the most severe pulmonary function impairment. Tidal breathing pulmonary function test may provide a reference for pathogen analysis of children with pertussis-like coughing.