RESUMO
OBJECTIVE: The objective of this study was to compare serial changes in pulmonary function in contemporary infants with congenital diaphragmatic hernia managed with a gentle ventilation approach. STUDY DESIGN: Observational cohort, single-center study of infants ≥350/7 weeks gestation at delivery with congenital diaphragmatic hernia. Functional residual capacity (FRC), passive respiratory compliance, and passive respiratory resistance were measured presurgical and postsurgical repair and within 2 weeks of discharge. A 1-way analysis of variance for repeated measures was used to evaluate the change in FRC, passive respiratory compliance, and passive respiratory resistance over these repeated measures. RESULTS: Twenty-eight infants were included in the analysis with a mean gestational age of 38.3 weeks and birth weight of 3139 g. We found a significant increase in FRC across the 3 time points (mean in mL/kg [SD]: 10.9 [3.6] to 18.5 [5.2] to 24.2 [4.4]; P < .0001). There was also a significant increase in passive respiratory compliance and decrease in passive respiratory resistance. In contrast to a previous report, there were survivors in the current cohort with a preoperative FRC of <9 mL/kg. The mean FRC measured at discharge was in the range considered within normal limits. Sixteen infants had prenatal measurements of the lung-to-head ratio, but there was no relationship between the lung-to-head ratio and preoperative or postoperative FRC measurements. CONCLUSIONS: Infants with congenital diaphragmatic hernia demonstrate significant increases in FRC and improvements in respiratory mechanics measured preoperatively and postoperatively and at discharge. We speculate these improvements are due to the surgical resolution of the mechanical obstruction to lung recruitment and that after achieving preoperative stability, repair should not be delayed given these demonstrable postoperative improvements.
Assuntos
Hérnias Diafragmáticas Congênitas , Lactente , Humanos , Hérnias Diafragmáticas Congênitas/complicações , Hérnias Diafragmáticas Congênitas/cirurgia , Pulmão , Capacidade Residual Funcional , Testes de Função Respiratória , Mecânica RespiratóriaRESUMO
OBJECTIVE: To compare pulmonary function tests (PFTs), specifically respiratory system resistance (Rrs) and compliance (Crs), in very low birth weight (VLBW) infants with and without pulmonary hypertension. STUDY DESIGN: Infants were included who underwent PFTs at 34-38 weeks postmenstrual age (PMA) as part of our pulmonary hypertension screening guidelines for infants born at ≤1500 g requiring respiratory support at ≥34 weeks PMA. One pediatric cardiologist reviewed and estimated right ventricular or pulmonary arterial pressure and defined pulmonary hypertension as an estimated pulmonary arterial pressure or right ventricular pressure greater than one-half the systemic pressure. Rrs and Crs were measured with the single breath occlusion technique and functional residual capacity with the nitrogen washout method according to standardized criteria. RESULTS: Twelve VLBW infants with pulmonary hypertension and 39 without pulmonary hypertension were studied. Those with pulmonary hypertension had significantly lower birth weight and a trend toward a lower gestational age. There were no other demographic differences between the groups. The infants with pulmonary hypertension had significantly higher Rrs (119 vs 78 cmH2O/L/s; adjusted P = .012) and significantly lower Crs/kg (0.71 vs 0.92 mL/cmH2O/kg; P = .04). CONCLUSIONS: In this pilot study of VLBW infants screened for pulmonary hypertension at 34-38 weeks PMA, those with pulmonary hypertension had significantly increased Rrs and decreased Crs compared with those without pulmonary hypertension. Additional studies are needed to further phenotype infants with evolving BPD and pulmonary hypertension.
Assuntos
Resistência das Vias Respiratórias/fisiologia , Hipertensão Pulmonar/diagnóstico , Hipertensão Pulmonar/fisiopatologia , Doenças do Prematuro/diagnóstico , Doenças do Prematuro/fisiopatologia , Complacência Pulmonar/fisiologia , Estudos de Coortes , Feminino , Idade Gestacional , Humanos , Hipertensão Pulmonar/terapia , Recém-Nascido , Recém-Nascido Prematuro , Doenças do Prematuro/terapia , Recém-Nascido Pequeno para a Idade Gestacional , Recém-Nascido de muito Baixo Peso , Masculino , Triagem Neonatal , Projetos Piloto , Respiração Artificial , Testes de Função RespiratóriaRESUMO
OBJECTIVE: To compare changes in lung volumes, as measured by functional residual capacity (FRC), through to discharge in stable infants randomized to 2 weeks of extended continuous positive airway pressure CPAP (eCPAP) vs CPAP discontinuation (dCPAP). STUDY DESIGN: Infants born at ≤32 weeks of gestation requiring ≥24 hours of CPAP were randomized to 2 weeks of eCPAP vs dCPAP when meeting CPAP stability criteria. FRC was measured with the nitrogen washout technique. Infants were stratified by gestational age (<28 and ≥ 28 weeks) and twin gestation. A linear mixed-effects model was used to evaluate the change in FRC between the 2 groups. Data were analyzed blinded to treatment group allocation. RESULTS: Fifty infants were randomized with 6 excluded, for a total of 44 infants. Baseline characteristics were similar in the 2 groups. The infants randomized to eCPAP vs dCPAP had a greater increase in FRC from randomization through 2 weeks (12.6 mL vs 6.4 mL; adjusted 95% CI, 0.78-13.47; P = .03) and from randomization through discharge (27.2 mL vs 17.1 mL; adjusted 95% CI, 2.61-17.59; P = .01). CONCLUSIONS: Premature infants randomized to eCPAP had a significantly greater increase in FRC through discharge compared with those randomized to dCPAP. An increased change in FRC may lead to improved respiratory health. TRIAL REGISTRATION: ClinicalTrials.gov: NCT02249143.
Assuntos
Pressão Positiva Contínua nas Vias Aéreas/métodos , Doenças do Prematuro/terapia , Pulmão/fisiopatologia , Síndrome do Desconforto Respiratório do Recém-Nascido/terapia , Adulto , Feminino , Capacidade Residual Funcional , Humanos , Recém-Nascido de Baixo Peso , Recém-Nascido , Recém-Nascido Prematuro , Masculino , Projetos Piloto , Volume de Ventilação Pulmonar , Resultado do TratamentoRESUMO
OBJECTIVE: To compare respiratory compliance in late preterm infants (340/7-346/7 weeks) who received antenatal steroids vs matched late preterm infants who did not receive antenatal steroids. STUDY DESIGN: This was a single-center prospective cohort study. Patients were matched for birth weight, gestational age, race, and sex. Respiratory compliance was the primary outcome measured with the single breath occlusion technique. RESULTS: We studied 25 late preterm infants treated with antenatal steroids and 25 matched infants who did not receive antenatal steroids. The treated infants had a significantly increased respiratory compliance/kg (adjusted 95% CI 0.05, 0.49; P = .016) and fewer required continuous positive airway pressure (P = .007) or >24 hours of supplemental oxygen (P = .046). There was no difference in surfactant therapy. CONCLUSIONS: Respiratory compliance was significantly increased in this cohort of late preterm infants born at 340/7-346/7 weeks who received antenatal steroids compared with matched infants who did not receive antenatal steroids. Although not randomized, these data provide physiologic support for the possible beneficial effects of antenatal steroids in late preterm infants.
Assuntos
Betametasona/uso terapêutico , Terapias Fetais , Glucocorticoides/uso terapêutico , Recém-Nascido Prematuro , Complacência Pulmonar , Adulto , Estudos de Casos e Controles , Estudos de Coortes , Pressão Positiva Contínua nas Vias Aéreas/estatística & dados numéricos , Feminino , Idade Gestacional , Humanos , Recém-Nascido , Masculino , Oxigenoterapia/estatística & dados numéricos , Gravidez , Cuidado Pré-Natal , Surfactantes Pulmonares/uso terapêutico , Síndrome do Desconforto Respiratório do Recém-Nascido/prevenção & controle , Testes de Função RespiratóriaRESUMO
OBJECTIVE: To compare the pulmonary function, measured at birth and at hospital discharge, of infants whose mothers had been randomized to a single rescue course of antenatal steroids versus those whose mothers had been randomized to placebo. STUDY DESIGN: This study involved follow-up at hospital discharge of subjects of a randomized, double-blinded trial. In the original trial, pregnant women at ≥14 days after their initial course of antenatal steroids and <34 weeks' gestation were randomized to rescue antenatal steroids (44 mothers, 56 infants) or placebo (41 mothers, 57 infants). Passive respiratory compliance (Crs), passive respiratory resistance, and functional residual capacity were measured in all infants at birth and again at discharge to evaluate changes in pulmonary mechanics over time. Statistical analyses were based on intention to treat. RESULTS: We previously reported that compared with infants in the placebo group, infants in the rescue antenatal steroids group had a higher mean Crs value measured within 72 hours of birth (1.21 vs 1.01 mL/cm H2O/kg; P < .05). Here we show that the Crs benefit in the antenatal steroids group was sustained until discharge. Infants in the placebo group demonstrated improvement in Crs such that by discharge, there was no difference in mean Crs between the rescue antenatal steroids and placebo groups (1.18 vs 1.22 mL/cm H2O/kg). CONCLUSIONS: Rescue antenatal steroids significantly increased Crs measured within 72 hours of birth, and this increase was sustained until hospital discharge. Preterm infants in the placebo group demonstrated a decreased initial Crs compared with the rescue antenatal steroids group, but achieved a comparable Crs by the time of discharge. TRIAL REGISTRATION: ClinicalTrials.gov: NCT00669383.
Assuntos
Betametasona/administração & dosagem , Recém-Nascido Prematuro , Complacência Pulmonar/efeitos dos fármacos , Síndrome do Desconforto Respiratório do Recém-Nascido/tratamento farmacológico , Adulto , Feminino , Seguimentos , Capacidade Residual Funcional/efeitos dos fármacos , Idade Gestacional , Glucocorticoides/administração & dosagem , Humanos , Recém-Nascido , Unidades de Terapia Intensiva Neonatal , Masculino , Alta do Paciente , Gravidez , Cuidado Pré-Natal/métodos , Estudos Prospectivos , Valores de Referência , Testes de Função Respiratória , Medição de Risco , Resultado do TratamentoRESUMO
OBJECTIVE: To compare pulmonary function testing including respiratory compliance (Crs) and time to peak tidal expiratory flow to expiratory time (TPTEF:TE) at term corrected age in healthy infants born at 33-36 weeks of gestation versus healthy infants delivered at term. STUDY DESIGN: We performed a prospective cohort study of late preterm infants born at 33-36 weeks without clinical respiratory disease (<12 hours of >0.21 fraction of inspired oxygen) and studied at term corrected age. The comparison group was term infants matched for race and sex to the preterm infants and studied within 72 hours of delivery. Crs was measured with the single breath occlusion technique. A minimum of 50 flow-volume loops were collected to estimate TPTEF:TE. RESULTS: Late preterm infants (n = 31; mean gestational age 34.1 weeks, birth weight 2150 g) and 31 term infants were studied at term corrected age. The late preterm infants had decreased Crs (1.14 vs 1.32 mL/cm H(2)O/kg; P < .02) and decreased TPTEF:TE (0.308 vs 0.423; P < .01) when compared with the term infants. Late preterm infants also had an increased respiratory resistance (0.064 vs 0.043 cm H(2)O/mL/s; P < .01). CONCLUSIONS: Healthy late preterm infants (33-36 weeks of gestation) studied at term corrected age have altered pulmonary function when compared with healthy term infants.