RESUMO
OBJECTIVE: To investigate the effects of distending pressures on respiratory mechanics and pulmonary circulation in newborn infants with congenital diaphragmatic hernia (CDH) and persistent pulmonary hypertension (PPHN). STUDY DESIGN: In total, 17 consecutive infants of ≥37 weeks of gestational age with CDH and PPHN were included in this prospective, randomized, crossover pilot study. Infants were assigned randomly to receive 2 or 5 cmH2O of positive end-expiratory pressure (PEEP) for 1 hour in a crossover design. The difference between peak inspiratory pressure and PEEP was kept constant. Respiratory mechanics, lung function, and hemodynamic variables assessed by Doppler echocardiography were measured after each study period. RESULTS: At 2 cmH2O of PEEP, tidal volume and minute ventilation were greater (P < .05), and respiratory system compliance was 30% greater (P < .05) than at 5 cmH2O. PaCO2 and ventilation index were lower at 2 cmH2O than at 5 cmH2O (P < .05). Although preductal peripheral oxygen saturation was similar at both PEEP levels, postductal peripheral oxygen saturation was lower (median [range]: 81% [65-95] vs 91% [71-100]) and fraction of inspired oxygen was greater (35% [21-70] vs 25% [21-60]) at 5 cmH2O. End-diastolic left ventricle diameter, left atrium/aortic root ratio, and pulmonary blood flow velocities in the left pulmonary artery were lower at 5 cmH2O. CONCLUSIONS: After surgical repair, lower distending pressures result in better respiratory mechanics in infants with mild-to-moderate CDH. We speculate that hypoplastic lungs in CDH are prone to overdistension, with poor tolerance to elevation of distending pressure.
Assuntos
Hérnias Diafragmáticas Congênitas/fisiopatologia , Hipertensão Pulmonar/etiologia , Complacência Pulmonar/fisiologia , Pulmão/fisiopatologia , Respiração com Pressão Positiva/métodos , Estudos Cross-Over , Ecocardiografia Doppler , Feminino , Seguimentos , Hérnias Diafragmáticas Congênitas/complicações , Hérnias Diafragmáticas Congênitas/terapia , Humanos , Hipertensão Pulmonar/diagnóstico , Hipertensão Pulmonar/fisiopatologia , Recém-Nascido , Masculino , Projetos Piloto , Estudos Prospectivos , Pressão Propulsora Pulmonar/fisiologiaRESUMO
OBJECTIVE: To evaluate the status of congenital diaphragmatic hernia (CDH) management in France and to assess predictors of adverse outcomes. STUDY DESIGN: We reviewed the first-year outcome of all cases of CDH reported to the French National Register in 2011. RESULTS: A total of 158 cases were included. Of these, 83% (131) were prenatally diagnosed, with a mortality rate of 39% (44 of 112) for live born infants with a known outcome at hospital discharge. Mortality increased to 47% (60 of 128) including those with termination of pregnancy and fetal loss. This contrasts with the 7% (2 of 27) mortality rate of the patients diagnosed postnatally (P = .002). Mortality worsened with 1 prenatal marker of CDH severity (OR 3.38 [1.30-8.83] P = .013) and worsened further with 2 markers (OR 20.64 [5.29-80.62] P < .001). Classic postnatal risk factors of mortality such as side of hernia (nonleft P = .001), prematurity (P < .001), low birth weight (P = .002), and size of the defect (P < .001) were confirmed. Of the 141 live births (114 prenatal and 27 postnatal diagnosis) with known outcomes, 93 (67%) survived to hospital discharge, 68 (60%) with a prenatal diagnosis and 25 (93%) with a postnatal diagnosis. The median time to hospital discharge was 34 days (IQR, 19.25-62). Of these survivors, 71 (76%) were followed up for 1 year. CONCLUSIONS: Despite advances in management of CDH, mortality was high and associated with prenatal risk factors. Postnatally, severe persistent pulmonary hypertension was difficult to predict and presented persistent challenges in management.
Assuntos
Hérnias Diafragmáticas Congênitas/mortalidade , Feminino , França , Hérnias Diafragmáticas Congênitas/terapia , Humanos , Lactente , Mortalidade Infantil , Recém-Nascido , Masculino , Gravidez , Cuidado Pré-Natal , Diagnóstico Pré-Natal , Estudos Prospectivos , Sistema de Registros , Fatores de Risco , Taxa de Sobrevida , Resultado do TratamentoRESUMO
OBJECTIVE: To compare breathing patterns and lung function in the supine, lateral, and prone positions in oxygen-dependent preterm infants. STUDY DESIGN: Respiratory function in preterm infants receiving nasal continous positive airway pressure therapy for mild respiratory failure was evaluated by respiratory inductive plethysmography. Infants were randomized to supine, left lateral, and prone positions for 3 hours. A nest provided a semiflexed posture for the infants placed in the left lateral position, similar to the in utero position. Tidal volume (Vt), phase angle between abdominal and thoracic movements, rib cage contribution to Vt, and dynamic elevation of end-expiratory lung volume were measured. RESULTS: Fraction of inspired O2 was similar in the 3 positions for 19 infants (mean gestational age, 27±2 weeks; mean birth weight, 950±150 g; mean postnatal age, 17±5 days). However, arterial O2 saturation and Vt were higher in the left lateral and prone positions than in the supine position (P<.05). The phase angle between abdominal and thoracic movements was lower and rib cage contribution to Vt was higher in the left lateral and prone positions than in the supine position (P<.05). Dynamic elevation of end-expiratory lung volume was greater in the supine position than in the left lateral and prone positions (P<.05). CONCLUSION: In oxygen-dependent preterm infants, both the left lateral and prone positions improve lung function by optimizing breathing strategy. In the neonatal intensive care unit, the left lateral position can be used as an alternative to the prone position for mild respiratory failure.
Assuntos
Doenças do Prematuro/fisiopatologia , Pulmão/fisiopatologia , Posicionamento do Paciente , França , Humanos , Recém-Nascido , Recém-Nascido Prematuro , Unidades de Terapia Intensiva Neonatal , Pletismografia , Respiração , Testes de Função RespiratóriaRESUMO
OBJECTIVE: To determine the hemodynamic impact of fluid restriction in preterm newborns with significant patent ductus arteriosus. STUDY DESIGN: Newborns ≥24 and <32 weeks' gestational age with significant patent ductus arteriosus were eligible for this prospective multicenter observational study. We recorded hemodynamic and Doppler echocardiographic variables before and 24 hours after fluid restriction. RESULTS: Eighteen newborns were included (gestational age 24.8 ± 1.1 weeks, birth weight 850 ± 180 g). Fluid intake was decreased from 145 ± 15 to 108 ± 10 mL/kg/d. Respiratory variables, fraction of inspired oxygen, blood gas values, ductus arteriosus diameter, blood flow-velocities in ductus arteriosus, in the left pulmonary artery and in the ascending aorta, and the left atrial/aortic root ratio were unchanged after fluid restriction. Although systemic blood pressure did not change, blood flow in the superior vena cava decreased from 105 ± 40 to 61 ± 25 mL/kg/min (P < .001). The mean blood flow-velocity in the superior mesenteric artery was lower 24 hours after starting fluid restriction. CONCLUSIONS: Our results do not support the hypothesis that fluid restriction has beneficial effects on pulmonary or systemic hemodynamics in preterm newborns.
Assuntos
Permeabilidade do Canal Arterial/fisiopatologia , Doenças do Prematuro/fisiopatologia , Água/administração & dosagem , Ecocardiografia Doppler , Hemodinâmica , Humanos , Recém-Nascido , Recém-Nascido Prematuro , Pulmão/fisiopatologia , Estudos Prospectivos , Artéria Pulmonar/fisiopatologia , Fluxo Sanguíneo Regional/fisiologia , Veia Cava Superior/fisiopatologiaRESUMO
OBJECTIVE: To study the effects of dopamine on systemic arterial pressure (SAP) and systemic blood flow (SBF) (estimated with the superior vena cava [SVC] flow) in preterm infants with hypotension and patent ductus arteriosus (PDA). STUDY DESIGN: Clinical and echocardiographic variables were measured before and 2 hours after starting dopamine in premature infants <32 weeks gestational age with PDA and systemic hypotension. RESULTS: Seventeen premature infants were included (gestational age, 28+/-2 weeks; birth weight, 1030 +/- 400 g). A mean rate of 8 +/- 2 microg/kg/min of dopamine raised SAP from 30 +/- 3 to 41 +/- 5 mm Hg (P < .05), and the pulmonary artery pressures from 25 +/- 5 to 32 +/- 8 mm Hg (P < .05). The SVC flow increased by 30% (from 130 +/- 40 to 170 +/- 44 mL/kg/min; P < .05). The left ventricular output and the end-diastolic and mean left pulmonary artery blood flow velocities did not change despite the increase in pulmonary artery pressure. CONCLUSION: In preterm infants with hypotension and PDA, dopamine (<10 microg/kg/min) increases the systemic blood pressure and the systemic blood flow. Our results suggest that dopamine decreases left-to-right shunting across ductus arteriosus, caused by a rise in pulmonary vascular resistances.
Assuntos
Cardiotônicos/uso terapêutico , Dopamina/uso terapêutico , Permeabilidade do Canal Arterial/complicações , Hipotensão/tratamento farmacológico , Hipotensão/etiologia , Pressão Sanguínea/efeitos dos fármacos , Eletrocardiografia , França , Humanos , Recém-Nascido , Recém-Nascido Prematuro , Unidades de Terapia Intensiva Neonatal , Estudos ProspectivosRESUMO
OBJECTIVE: To evaluate the respiratory and the pulmonary circulatory effects of norepinephrine in newborn infants with persistent pulmonary hypertension (PPHN)-induced cardiac dysfunction. STUDY DESIGN: Inclusion criteria were: 1) Newborn infants >35 weeks gestational age; 2) PPHN treated with inhaled nitric oxide; and 3) symptoms of circulatory failure despite adequate fluid resuscitation. Lung function and pulmonary hemodynamic variables assessed with Doppler echocardiography were recorded prospectively before and after starting norepinephrine. RESULTS: Eighteen newborns were included (gestational age: 37 +/- 3 weeks; birth weight: 2800 +/- 700 g). After starting norepinephrine, systemic pressure and left ventricular output increased respectively from 33 +/- 4 mm Hg to 49 +/- 4 mm Hg and from 172 +/- 79 mL/kg/min to 209+/-90 mL/kg/min (P < .05). Although the mechanical ventilatory variables have not been changed, the post-ductal transcutaneous arterial oxygen saturation increased from 89% +/- 1% to 95% +/- 4%, whereas the oxygen need decreased from 51% +/- 24% to 41% +/- 20% (P < .05). The pulmonary/systemic pressure ratio decreased from 0.98 +/- 0.1 to 0.87 +/- 0.1 (P < .05). Mean left pulmonary artery blood flow velocity increased by 20% (P < .05). CONCLUSION: Norepinephrine may improve lung function in newborn infants with PPHN through a decrease in pulmonary/systemic artery pressure ratio and improved cardiac performance.