RESUMO
OBJECTIVE: To test whether low variability of tidal volume (VT) and capnographic indices are predictive of subsequent respiratory morbidity in preterm infants. STUDY DESIGN: In a birth cohort of 133 preterm infants, lung function was performed at 44 weeks postmenstrual age. Associations between the coefficient of variation (CV) of VT (CVVT) and of expired CO2 volume per breath (CVVE,CO2) with rehospitalization, wheeze, and inhalation therapy during infancy were assessed using logistic regression. Area under the curve (AUC) analysis was used to assess whether outcome prediction using bronchopulmonary dysplasia (BPD) classification was enhanced by CVVT or CVVE,CO2. RESULTS: For each IQR decrease in CVVT (range, 4%-35%) and CVVE,CO2 (range, 5%-40%), the OR for rehospitalization increased by 2.25 (95% CI, 1.21-4.20) and 2.31 (95% CI, 1.20-4.45), respectively. The predictive value of BPD for rehospitalization was improved when CVVT or CVVE,CO2 was added to the model, with the AUC increasing from 0.56 to 0.66 in both models. No association was found for the other outcomes. CONCLUSIONS: Compared with BPD classification alone, including near-term variability of tidal breathing parameters improves the prediction of rehospitalization in infancy. These findings may inform parent counseling and monitoring strategies in preterm infants.
Assuntos
Displasia Broncopulmonar/fisiopatologia , Pulmão/fisiopatologia , Volume de Ventilação Pulmonar/fisiologia , Capnografia/métodos , Feminino , Idade Gestacional , Humanos , Lactente , Recém-Nascido , Recém-Nascido Prematuro , Modelos Logísticos , Masculino , Readmissão do Paciente , Estudos Prospectivos , Curva ROC , Respiração Artificial/métodos , Respiração Artificial/estatística & dados numéricos , Testes de Função Respiratória/métodos , Taxa Respiratória , Fatores de Risco , Índice de Gravidade de DoençaRESUMO
OBJECTIVE: To assess the impact of potential risk factors on the development of respiratory symptoms and their specific modification by breastfeeding in infants in the first year of life. STUDY DESIGN: We prospectively studied 436 healthy term infants from the Bern-Basel Infant Lung Development cohort. The breastfeeding status, and incidence and severity of respiratory symptoms (score) were assessed weekly by telephone interview during the first year of life. Risk factors (eg, pre- and postnatal smoking exposure, mode of delivery, gestational age, maternal atopy, and number of older siblings) were obtained using standardized questionnaires. Weekly measurements of particulate matter <10 µg were provided by local monitoring stations. The associations were investigated using generalized additive mixed model with quasi Poisson distribution. RESULTS: Breastfeeding reduced the incidence and severity of the respiratory symptom score mainly in the first 27 weeks of life (risk ratio 0.70; 95% CI 0.55-0.88). We found a protective effect of breastfeeding in girls but not in boys. During the first 27 weeks of life, breastfeeding attenuated the effects of maternal smoking during pregnancy, gestational age, and cesarean delivery on respiratory symptoms. There was no evidence for an interaction between breastfeeding and maternal atopy, number of older siblings, child care attendance, or particulate matter <10 µg. CONCLUSIONS: This study shows the risk-specific effect of breastfeeding on respiratory symptoms in early life using the comprehensive time-series approach.
Assuntos
Aleitamento Materno , Tosse/epidemiologia , Transtornos Respiratórios/epidemiologia , Sons Respiratórios , Tosse/prevenção & controle , Feminino , Humanos , Incidência , Lactente , Recém-Nascido , Masculino , Distribuição de Poisson , Estudos Prospectivos , Transtornos Respiratórios/prevenção & controle , Fatores de RiscoRESUMO
OBJECTIVES: To assess the feasibility of using volumetric capnography in spontaneously breathing small infants and its ability to discriminate between infants with and without bronchopulmonary dysplasia (BPD). STUDY DESIGN: Lung function variables for 231 infants (102 term, 52 healthy preterm, 77 BPD), matched for post-conceptional age of 44 weeks, were collected. BPD was defined as supplemental oxygen requirement at 36 weeks post-menstrual age. Tidal breath-by-breath volume capnograms were obtained by mainstream capnography. The capnographic slope of phase II (SII) and slope of phase III (SIII) were calculated and compared between study groups. The effect of BPD, tidal volume (VT), respiratory rate (RR), and prematurity on the magnitude of the slopes was assessed. RESULTS: SII was steeper in infants with BPD (100 ± 28/L) compared with healthy preterm (88 ± 22/L; P = .007) and term infants (79 ± 18/L; P < .001), but this finding was attributed to differences in VT, RR, and gestational age. SIII was steeper in the BPD group (26.8 ± 14.1/L) compared with healthy preterm (16.2 ± 6.2/L; P < .001) and term controls (14.8 ± 5.4/L; P < .001). BPD was a significant predictor of SIII independently of VT, RR, and gestational age. The ability of SIII to discriminate between BPD and controls was significantly higher compared with lung clearance index (area under the curve 0.83 vs 0.56; P < .001). CONCLUSIONS: Volumetric capnography may provide valuable information regarding functional lung alterations related to BPD and might be considered as an alternative to more involved lung function techniques for monitoring chronic lung disease during early infancy.