Risk factors for acute respiratory syncytial virus infection of lower respiratory tract in hospitalized infants / 中华儿科杂志

<p><b>OBJECTIVE</b>To investigate the clinical epidemiologic characteristics and analyze risk factors for acute respiratory syncytial virus (RSV) infection in hospitalized infants with acute lower respiratory tract infection (ALRI).</p><p><b>METHOD</b>ALRI infants admitted to Children's Hospital of Fudan University from March 1st, 2011 to February 29th, 2012, were enrolled in this study. Patient information included demographic characteristics, feeding history, family status, clinical presentation, accessory examination, treatment and prognosis. According to the etiology of ALRI infants, we compared the seasonal distribution, demographic characteristics, household characteristics and underlying diseases between RSV-positive patients and RSV-negative patients. Univariate and multiple Logistic regression analyses were used to determine factors that were associated with risk of RSV infection.</p><p><b>RESULT</b>Among 1 726 ALRI infants, there were 913 RSV-positive infants (52.9%). The occurrence of RSV infection had a seasonal variation, with a peak in winter (59.1%). The median (P25, P75) age of RSV infants was 64 (21-155) days. The gestational age (GA) and body weight (BW) was (37.5 ± 2.4) weeks and (3.07 ± 0.66) kg, respectively. The male/female ratio among these was 1.9: 1. RSV infection was more popular among infants in the families with smoking members, crowded living conditions, history of atopic mother. Differences of the proportion of patients with underlying disease between RSV-positive and negative groups were statistically significant (59.4% vs. 54.2%, P < 0.05). Univariate logistic regression demonstrated that factors increasing the risk of RSV infection were: GA<37 weeks (OR = 1.346, 95%CI: 1.037-1.748), birth weight <2 500 g (OR = 1.447, 95%CI: 1.103-1.898), underlying diseases (OR = 1.232, 95%CI: 1.018-1.492), underlying CHD (OR = 1.391, 95%CI: 1.120-1.728), environmental tobacco smoke exposure (OR = 1.254, 95%CI: 1.035-1.519), mother with atopic diseases (OR = 1.827, 95%CI: 1.296-2.573), crowded house with four or more than four family members (OR = 1.232, 95%CI: 1.013-1.498), autumn or winter infection (OR = 1.351, 95%CI: 1.024-1.783; OR = 1.713, 95%CI: 1.332-2.204). Multivariate logistic regression determined the factors increasing the risk of RSV infection were: underlying CHD (OR = 1.298, 95%CI: 1.002-1.681), mother with atopic diseases (OR = 1.766, 95%CI: 1.237-2.520), autumn or winter infection (OR = 1.481, 95%CI: 1.105-1.985; OR = 1.766, 95%CI: 1.358-2.296).</p><p><b>CONCLUSION</b>The prevalence of RSV infection was the highest in winter, while preterm and low birth weight infants were more susceptible. Underlying diseases were found in 59.4% cases, CHD was the most common one. The factors increasing the risk of RSV infection were: CHD, mother with atopic diseases, autumn or winter infections.</p>

Lung function measurements using body plethysmography in young children with acute lower respiratory tract infection / 中华儿科杂志

<p><b>OBJECTIVE</b>Body plethysmography is a typical method to measure functional residual capacity (FRC) and airway resistance (Raw). The aim of the study was to test the feasibility of measuring lung function with the body plethysmography in young children with acute lower respiratory tract infection (ALRI) by evaluating changes and prognosis of lung function for infants with ALRI with or without wheezing via body plethysmograph.</p><p><b>METHOD</b>Pulmonary function tests (PFTs) were performed by using body plethysmography in 444 children with ALRI, aged 1-36 months, to assess their tidal breathing parameters such as ratio of time to peak tidal expiratory flow to total expiratory time (TPTEF/TE), ratio of volume to peak tidal expiratory flow to total expiratory volume (VPTEF/VE), plethysmographic functional residual capacity (FRCP), FRCP per kilogram (FRCP/kg), specific effective airway resistance (sReff), effective airway resistance (Reff), Reff per kilogram (Reff/kg), etc. According to whether there was wheezing or not, children who had ALRI with wheezing were classified as Group-W, or without wheezing as Group-N. Changes or correlations of tidal breathing parameters and plethysmographic parameters were compared.One hundred and three contemporaneous healthy controls aged 1-36 months underwent the same tests for comparison. And 36 wheezing children accepted PFTs at follow-up in recovery phase.</p><p><b>RESULT</b>Mean values of TPTEF/TE in Group-W,Group-N and the Control respectively were (20.5 ± 6.7)%,(22.8 ± 6.5)%,(34.6 ± 5.0)% (F = 110.500, P < 0.001), while VPTEF/VE respectively were (23.0 ± 6.3)%,(25.2 ± 6.8)%,(34.5 ± 4.2)% (F = 107.800, P < 0.001). Compared to the Control,Group-W and Group-N had significantly higher values of FRCP (226 vs. 176 vs. 172 ml, χ(2) = 64.870, P < 0.001), FRCP/kg(24.40 vs.17.80 vs.17.60 ml/kg,χ(2) = 68.890, P < 0.001), sReff(1.00 vs. 0.52 vs. 0.46 kPa·s,χ(2) = 75.240, P < 0.001), Reff (3.90 vs.2.74 vs.2.20 kPa·s/L, χ(2) = 36.480, P < 0.001) and Reff/kg [0.42 vs. 0.29 vs.0.22 kPa·s/(L·kg), χ(2) = 29.460, P < 0.001]. Although 25 (12.8%) wheezing children with ALRI had normal values of tidal breathing parameters, they already had increased FRCP, FRCP /kg, sReff, Reff and Reff/kg (t = 2.221, 1.997, 2.502, 2.587, 2.539, all P < 0.05). Values of FRCP and Reff in infants caught ALRI were inversely correlated to that of TPTEF/TE and VPTEF/VE (P < 0.05); 36 children with wheezing who accepted PFTs at follow-up had shown significant decline in the specific parameters of plethysmography such as FRCP, FRCP/kg, sReff, Reff and Reff/kg (Z = -1.999, -2.195, -2.038, -1.823, -2.054, all P < 0.05), while no improvement in the main parameters of tidal breathing such as TPTEF/TE.</p><p><b>CONCLUSION</b>Measuring lung function with the body plethysmography in young children with ALRI is feasible. FRC and Raw, as special lung function testing parameters of body plethysmography, were sensitive indicators reflecting impairment of lung function in infants with ALRI (especially for children caught ALRI with wheezing) and shows significant correlation with parameters from lung function testing via tidal breathing. Therefore plethysmography is worthy of clinical promotion.</p>

Research advances of baby body plethysmography / 中华实用儿科临床杂志

Baby body plethysmography is a well-established technique of lung function determination,which is widely used to access the respiratory development and obstructive airway diseases by precisely measuring tidal breathing,functional residual capacity,and air way resistance.Babies who accept lung function measurements in the baby body plethysmography are under quiet state of spontaneous breathing without any subjective initiative,which results in multiplexed data acquisition,high precision and good repeatability.Clinical application of baby body plethysmography differs in different countries and areas,with the most intensive application in the German-speaking countries.In China,the clinical use of baby body plethysmography still remains in primary stage.Great progress has been achieved in its clinical use during the past 20 years,but there is still a lack of consensus on normal reference values or equations with which to interpret results,which has caused some trouble to diagnosis and identification of respiratory disease.In order to identify the nature and severity of airway disease,it is essential to understand the normal range of plethysmographic values that may occur in healthy infants of similar age,gender and body size.

Lung function measurement by using baby body plethysmography in newborns with pneumonia / 中华实用儿科临床杂志

Objective To access the changes of lung function of newborns with pneumonia and to investigate the feasibility of measuring lung function in the body plcthysmograph for diagnosing and treating respiratory diseases.Methods There were 117 infants,1 day after being diagnosed with mild or moderate pneumonia,aged 4-28 days,involved in the study,those who needed oxygen cure,mechanical ventilation,or had complications from pneumonia were ruled out.Pulmonary function tests (PFTs) were performed in the baby body plethysmography to access tidal breathing,plethysmographic functional residual capacity (FRCp),and effective airway resistance (Reff).The other 126 contemporaneous healthy children took the same test for comparison.According to their ages,infants were grouped into 4-7 d,8-14 d,15-21 d and 22-28 d.Results Of the 117 infants with pneumonia,79 (67.5 ％ equivalently) had abnormal lung function.Compared with the controls,infants with pneumonia had significantly higher values of peak tidal expiratory flow [(59.4 ± 16.6) mL/s vs (52.9 ± 16.6) mL/s],expiratory flow at 75％ tidal volume [(57.4 ± 16.7) mL/s vs (49.5 ± 16.7) mL/s],special effective airway resistance (0.48 kPa · s vs O.27 kPa · s),Reff [6.96 kPa · s/L vs 4.82 kPa · s/L] and Reff per kilogram [1.99 kPa · s/(L · kg) vs 1.44 kPa · s/(L · kg)],but lower values of time to peak tidal expiratory flow as a percentage of total expiratory time [(26.5 ± 10.0) ％ vs (36.8 ± 9.9) ％],volume to peak tidal expiratory flow as a percentage of total expiratory volune [(27.9 ± 7.3) ％ vs (35.6 ± 8.4) ％]and expiratory flow at 25％ tidal volume [(36.3 ± 11.7) mL/s vs (40.1 ± 12.4) mL/s].There were no sig± nificant differences in the values of respiratory rate,FRCp and FRCp/kg between the pneumonia children and the healthy control chidren.Compared with the infants aged ≤ 14 days,there were more significant differences in relative parameters of lung funetion between the pneumonia group and the healthy control group for infants aged 15-28 days.Conclusions Newborns with pneumonia had a high ratio of abnormal lung function,which went up to 67.5％,and had apparent obstruction of small airways.Neonates with pneumonia aged 15-28 days had more apparent lesion of lang function.Measuring lang function by means of plethysmography among newborns is feasible and it can detect abnormal lung function sensitively.