RESUMO
OBJECTIVE: To determine pulmonary mechanical characteristics in neonates after cardiac surgery. DESIGN: A prospective study. SETTING: A 23-bed, pediatric ICU in a 280-bed children's hospital. PATIENTS: Twenty-six infants on the first post-operative day after cardiac surgery. METHODS: Pulmonary mechanics measurements were made during spontaneous breathing, using the esophageal balloon technique and a pneumotachometer. The least mean square method of analysis was used to calculate mechanics. Infants who tolerated withdrawal of mechanical ventilation (group 1) were compared with those infants with respiratory failure (group 2). RESULTS: Spontaneous respiratory rate, tidal volume, and minute ventilation were similar in groups 1 and 2. Lung compliance was decreased, with no difference between groups. Total lung resistance (34.3 +/- 21.6 cm H2O/L.sec in group 1 vs. 136.8 +/- 105.8 cm H2O/L.sec in group 2, p = .002) and resistive work of breathing (33.4 +/- 29.9 g.cm/kg in group 1 vs. 212.9 +/- 173.8 g.cm/kg in group 2, p = .001) were significantly higher in group 2. All infants with a total lung resistance greater than 75 cm H2O/L.sec exhibited respiratory failure (resistance greater than 75 cm H2O/L.sec correlated with respiratory failure, r2 = .73, odds ratio of 70 [confidence interval, 4.4 to 3240], p less than .001). CONCLUSIONS: Increased lung resistance identifies neonates with respiratory failure after cardiac surgery. Pulmonary mechanics testing may be useful in timing withdrawal of mechanical ventilation.
Assuntos
Cardiopatias Congênitas/cirurgia , Complicações Pós-Operatórias/fisiopatologia , Insuficiência Respiratória/fisiopatologia , Mecânica Respiratória , Resistência das Vias Respiratórias , Gasometria , Humanos , Recém-Nascido , Complacência Pulmonar , Medidas de Volume Pulmonar , Complicações Pós-Operatórias/epidemiologia , Complicações Pós-Operatórias/terapia , Valor Preditivo dos Testes , Estudos Prospectivos , Respiração Artificial , Insuficiência Respiratória/epidemiologia , Insuficiência Respiratória/terapia , Fatores de Risco , Taxa de Sobrevida , Desmame do Respirador , Aumento de PesoAssuntos
Hipotermia Induzida , Pentobarbital/uso terapêutico , Síndrome de Reye/terapia , Edema Encefálico/prevenção & controle , Criança , Coma/induzido quimicamente , Humanos , Pressão Intracraniana/efeitos dos fármacos , Avaliação de Processos e Resultados em Cuidados de Saúde , Síndrome de Reye/complicaçõesRESUMO
Arterial oxygen tension and functional residual capacity were studied in 16 intubated, spontaneously breathing newborn infants recovering from respiratory disease. Studies were made at 2 cm H2O continuous positive airway pressure, at zero end expiratory pressure, and following extubation. The study showed that PaO2 and FRC at 2 cm H2O CPAP were the same as observed following extubation, but that both values were significantly lower at ZEEP.