RESUMO
The objective of this study was to compare the conventional method of measuring respiratory mechanics, which requires the passage of an esophageal tube, with the occlusion technique, which is less invasive. Thirty-nine preterm infants who received mechanical ventilation on the first day were studied before discharge (mean +/- SD: postnatal age 67 +/- 23 days; weight 1790 +/- 300 gm), and 27 of them again at 1 year (weight 8.1 +/- 1.4 kg). Flows were measured through a nosepiece by pneumotachometry, tidal volume by integration of flow, esophageal pressure through a water-filled tube, and airway pressure directly at the nasal piece. Airway occlusion was performed at the end of inspiration, and the following relaxed exhalation was analyzed to give compliance (Crs) and resistance (Rrs) of the respiratory system. These values were compared with dynamic lung compliance (Cdyn) and expiratory resistance (Re) of the previous unoccluded breath. In the younger infants, dynamic and static measurements did not differ significantly and were well correlated (Cdyn/Crs, r = 0.91; Re/Rrs, r = 0.95). In the older infants, Crs was 80% of Cdyn (p less than 0.001), and Rrs was 24% higher than Re (p less than 0.001). The measurements were well correlated (Cdyn/Crs, r = 0.94; Re/Rrs, r = 0.91). The regression line Cdyn versus Crs had a slope (0.77) significantly less than 1; the regression Re versus Rrs had an intercept (13.8) significantly greater than zero. The lower Crs and higher Rrs values can be expected because the static determinations include the chest wall. In the more immature infants, the very compliant chest wall, in combination with an underestimation of Cdyn because of the higher breathing frequency of these infants, may obscure this difference. We conclude that the occlusion technique gives accurate and reproducible results, is easily applied, does not need the passage of an esophageal tube, and is well tolerated by the infants.
Assuntos
Respiração , Testes de Função Respiratória/métodos , Doença Aguda , Humanos , Lactente , Recém-Nascido , Recém-Nascido Prematuro/fisiologia , Testes de Função Respiratória/instrumentação , Insuficiência Respiratória/fisiopatologiaRESUMO
To determine the incidence and outcome of neurosensory hearing loss in infants, without selection bias, volunteers screened all infants from intensive care and well-baby nurseries of a tertiary care center for risk factors over 1 year; infants with sufficient risk factors were screened for auditory brainstem evoked response. Infants with abnormal findings received audiometric follow-up. Results of a 1-year follow-up study are reported. Risk factor evaluation revealed a 17% incidence of neurosensory hearing loss in a subgroup of infants with multiple risks such as birth weight less than 1500 gm, with perinatal asphyxia, subsequent hypoxemia, and hospital stay greater than 2 months. All infants with permanent hearing loss were assigned to this category. Our results suggest that this population is at greatest risk for early hearing impairment.
Assuntos
Potenciais Evocados Auditivos , Perda Auditiva Neurossensorial/epidemiologia , Programas de Rastreamento/métodos , Audiometria , Seguimentos , Idade Gestacional , Humanos , Lactente , Recém-Nascido , Unidades de Terapia Intensiva Neonatal , Risco , Fatores de TempoRESUMO
The long-term effect of necrotizing enterocolitis on growth, nutritional status, and gastrointestinal function was assessed in premature infants at the age of 1 year. Of the 22 of 40 infants who developed NEC, 18 were given medical treatment and four required surgical treatment consisting of intestinal resection of less than one fourth of the small bowel. Eighteen infants who did not develop NEC served as controls. At 1 year follow-up, NEC survivors and controls had normal and comparable anthropometric measurements, biochemical values (serum iron, albumin, prealbumin, retinol binding protein, liver function studies) and gastrointestinal tract function (vitamin E absorption, fasting serum bile acids concentration, lactose breath test). This study demonstrates that, in the absence of short bowel syndrome, there is no detectable long-term effect on growth, nutritional status, and gastrointestinal tract function in premature infants who had NEC in the newborn period.
Assuntos
Fenômenos Fisiológicos do Sistema Digestório , Enterocolite Pseudomembranosa/fisiopatologia , Crescimento , Fenômenos Fisiológicos da Nutrição do Lactente , Antropometria , Seguimentos , Humanos , LactenteRESUMO
PPHN should be recognized as a clinical condition associated with a number of pulmonary and systemic diseases. Present therapy has resulted in increased survival, but the aggressive methods required to produce improvement necessitate a clear understanding of the underlying pathophysiology in order to minimize sequelae.