| Objective To study on the normal ranges of indexes of tidal breathing pulmonary function in children under 5 years old inMianyang area of Sichuan Province.Methods From September 2021 to October 2022, a total of 456 children, including healthy chil-dren under 5 years old who had not been diagnosed as sick through examination at the pediatric outpatient department of Mianyang Ma-ternal and Child Health Hospital, normal children examined at the Children's Health Department and healthy children under 5 yearsold from 5 kindergartens, were randomly selected by cluster sampling method in a 1∶1∶1 ratio. The indexes of tidal breathing pulmo-nary function [tidal volume (VT), tidal volume per kilogram (VT/kg), minute ventilation (MV), respiratory rate (RR), inspiratory time(Ti), expiratory time (Te), inspiratory/expiratory time ratio (Ti/Te), total inspiratory/expiratory time (Ttot), peak tidal expiratory flow(PTEF), peak tidal inspiratory flow (PTIF), the ratio of the proportion of time to reach peak tidal expiratory flow to total expiratory time(tPTEF/tE), the ratio of volume to peak expiratory flow over total expiratory volume (VPEF/VE), tidal expiratory flow at 75% remainingtidal volume (TEF75), tidal expiratory flow at 50% remaining tidal volume (TEF50), tidal expiratory flow at 25% remaining tidal volume(TEF25), tidal expiratory flow at 50% remaining tidal volume to tidal inspiratory flow at 50% remaining tidal volume (TEF50/TIF50)]were detected. The normal ranges of tidal breathing pulmonary function for children of different genders and ages were obtained, andthe relevant factors were analyzed.Results Of the children selected 56.58% were boys and 43.42% were girls, and the proportions ofchildren aged 1 month to 2 years old, >2 to 3 years old, >3 to 4 years old and >4 to <5 years old were 11.84%, 12.06%, 45.84%, and30.26%, respectively. And 64.69% of them had close contact with smokers. The normal ranges of tidal breathing pulmonary function de-tection indexes for different genders and different ages had been identified. There were statistical differences in VT, VT/kg, MV, RR,PTEF, TEF75, TEF50, TEF25 among children of different genders (P<0.05), and there were statistical differences in VT, VT/kg, MV,RR, PTEF, TEF75, TEF50, TEF25, PTIF, Ti among children of different ages (P<0.05). Age, height, body mass and daily exercise timewere positively correlated with VT, MV, PTEF, PTIF and TEF25, and negatively correlated with RR. The above-mentioned indexes were negatively correlated with close contact with smoking, with statistical differences (P<0.05).Conclusion This study identifies thenormal ranges of tidal breathing pulmonary function in children under 5 years of age in Mianyang, which are correlated with age,height, body mass, daily exercise time and whether children are exposed to smoking. |
