RESUMEN
BACKGROUND: Constant-flow nasal continuous positive airway pressure (NCPAP) often is used in preterm neonates to recruit and maintain lung volume. Physical model studies indicate that a variable-flow NCPAP device provides more stable volume recruitment with less imposed work of breathing (WOB). Although superior lung recruitment with variable-flow NCPAP has been demonstrated in preterm neonates, corroborating WOB data are lacking. OBJECTIVE: To measure and compare WOB associated with the use of variable-flow versus constant-flow NCPAP in preterm neonates. METHODS: Twenty-four preterm infants who were receiving constant-flow NCPAP (means, SD) and had birth weight of 1024 +/- 253 g, gestational age of 28 +/- 1.7 weeks, age of 14 +/- 13 days, and FIO(2) of 0.3 +/- 0.1 were studied. Variable-flow and constant-flow NCPAP were applied in random order. We measured changes in lung volume and tidal ventilation (V(T)) by DC-coupled/calibrated respiratory inductance plethysmography as well as esophageal pressures at NCPAP of 8, 6, 4, and 0 cm H(2)O. Inspiratory WOB (WOB(I)) and lung compliance were calculated from the esophageal pressure and V(T) data using standard methods. WOB was divided by V(T) to standardize the results. RESULTS: WOB(I) decreased at all CPAP levels with variable-flow NCPAP, with a maximal decrease at 4 cm H(2)O. WOB(I) increased at all CPAP levels with constant-flow CPAP. Lung compliance increased at all NCPAP levels with variable-flow, with a relative decrease at 8 cm H(2)O, whereas it increased only at 8 cm H(2)O with constant-flow NCPAP. Compared with constant-flow NCPAP, WOB(I) was 13% to 29% lower with variable-flow NCPAP. CONCLUSION: WOB(I) is decreased with variable-flow NCPAP compared with constant-flow NCPAP. The increase in WOB(I) with constant-flow NCPAP indicates the presence of appreciable imposed WOB with this device. Our study, performed in neonates with little lung disease, indicates the possibility of lung overdistention at CPAP of 6 to 8 cm H(2)O with the variable-flow device. Further study is necessary to determine the efficacy of variable-flow NCPAP in neonates with significant lung disease and its use over extended periods of time.continuous-flow and variable-flow NCPAP, work of breathing, premature neonates, lung compliance.
Asunto(s)
Recien Nacido Prematuro/fisiología , Respiración con Presión Positiva/métodos , Trabajo Respiratorio/fisiología , Diseño de Equipo , Femenino , Humanos , Recién Nacido , Enfermedades del Prematuro/fisiopatología , Enfermedades del Prematuro/terapia , Masculino , Respiración con Presión Positiva/instrumentación , Pruebas de Función RespiratoriaRESUMEN
OBJECTIVE: To determine whether lung volume changes and breathing pattern parameters differ among 3 devices for delivery of nasal continuous positive airway pressure (CPAP) in premature infants. METHODS: Thirty-two premature infants receiving nasal CPAP for apnea or mild respiratory distress were enrolled. Birth weight was (mean +/- standard deviation) 1081 +/- 316 g, gestational age 29 +/- 2 weeks, age at study 13 +/- 12 days, and fraction of inspired oxygen (FIO(2)) at study.29 +/-.1. Three devices, applied in random order, were studied in each infant: continuous flow nasal CPAP via CPAP prongs, continuous flow nasal CPAP via modified nasal cannula, and variable flow nasal CPAP. After lung recruitment to standardize volume history, changes in lung volume (DeltaV(L)) were assessed at nasal CPAP of 8, 6, 4, and 0 cm H(2)O using calibrated direct current-coupled respiratory inductance plethysmography. RESULTS: DeltaV(L) was significantly greater overall with the variable flow device compared with both the nasal cannula and CPAP prongs. However, DeltaV(L) was not different between the cannula and the prongs. Respiratory rate, tidal volume, thoraco-abdominal asynchrony, and FIO(2) were greater with the modified cannula than for either of the other 2 devices. CONCLUSION: Compared with 2 continuous flow devices, the variable flow nasal CPAP device leads to greater lung recruitment. Although a nasal cannula is able to recruit lung volume, it does so at the cost of increased respiratory effort and FIO(2).
Asunto(s)
Recien Nacido Prematuro/fisiología , Respiración con Presión Positiva/instrumentación , Respiración , Apnea/terapia , Humanos , Recién Nacido , Enfermedades del Prematuro/fisiopatología , Enfermedades del Prematuro/terapia , Rendimiento Pulmonar , Nariz , Respiración con Presión Positiva/métodos , Insuficiencia Respiratoria/terapia , Capacidad Pulmonar TotalRESUMEN
Positive airway pressure (Paw) during high-frequency oscillatory ventilation (HFOV) increases lung volume and can lead to lung overdistention with potentially serious adverse effects. To date, no method is available to monitor changes in lung volume (DeltaVL) in HFOV-treated infants to avoid overdistention. In five newborn piglets (6-15 days old, 2.2-4.2 kg), we investigated the use of direct current-coupled respiratory inductive plethysmography (RIP) for this purpose by evaluating it against whole body plethysmography. Animals were instrumented, fitted with RIP bands, paralyzed, sedated, and placed in the plethysmograph. RIP and plethysmography were simultaneously calibrated, and HFOV was instituted at varying Paw settings before (6-14 cmH(2)O) and after (10-24 cmH(2)O) repeated warm saline lung lavage to induce experimental surfactant deficiency. Estimates of Delta VL from both methods were in good agreement, both transiently and in the steady state. Maximal changes in lung volume (Delta VL(max)) from all piglets were highly correlated with Delta VL measured by RIP (in ml) = 1.01 x changes measured by whole body plethysmography - 0.35; r(2) = 0.95. Accuracy of RIP was unchanged after lavage. Effective respiratory system compliance (Ceff) decreased after lavage, yet it exhibited similar sigmoidal dependence on Delta VL(max) pre- and postlavage. A decrease in Ceff (relative to the previous Paw setting) as Delta VL(max) was methodically increased from low to high Paw provided a quantitative method for detecting lung overdistention. We conclude that RIP offers a noninvasive and clinically applicable method for accurately estimating lung recruitment during HFOV. Consequently, RIP allows the detection of lung overdistention and selection of optimal HFOV from derived Ceff data.
Asunto(s)
Ventilación de Alta Frecuencia/efectos adversos , Pulmón/fisiopatología , Síndrome de Dificultad Respiratoria del Recién Nacido/terapia , Animales , Animales Recién Nacidos , Humanos , Recién Nacido , Pulmón/irrigación sanguínea , Mediciones del Volumen Pulmonar , Pletismografía , Surfactantes Pulmonares/fisiología , Mecánica Respiratoria/fisiología , PorcinosRESUMEN
Reported values of lung resistance (RL) and elastance (EL) in spontaneously breathing preterm neonates vary widely. We hypothesized that this variability in lung properties can be largely explained by both inter- and intrasubject variability in breathing pattern and demographics. Thirty-three neonates receiving nasal continuous positive airway pressure [weight 606-1,792 g, gestational age (GA) of 25-33 wk, 2-49 days old] were studied. Transpulmonary pressure was measured by esophageal manometry and airway flow by face mask pneumotachography. Breath-to-breath changes in RL and EL in each infant were estimated by Fourier analysis of impedance (Z) and by multiple linear regression (MLR). RL(MLR) (RL(MLR) = 0.85 x RL(Z) -0.43; r(2) = 0.95) and EL(MLR) (EL(MLR) = 0.97 x EL(Z) + 8.4; r(2) = 0.98) were highly correlated to RL(Z) and EL(Z), respectively. Both RL (mean +/- SD; RL(Z) = 70 +/- 38, RL(MLR) = 59 +/- 36 cm H(2)O x s x l(-1)) and EL (EL(Z) = 434 +/- 212, EL(MLR) = 436 +/- 210 cm H(2)O/l) exhibited wide intra- and intersubject variability. Regardless of computation method, RL was found to decrease as a function of weight, age, respiratory rate (RR), and tidal volume (VT) whereas it increased as a function of RR. VT and inspiratory-to-expiratory time ratio (TI/TE). EL decreased with increasing weight, age, VT and female gender and increased as RR and TI/TE increased. We conclude that accounting for the effects of breathing pattern variability and demographic parameters on estimates of RL and EL is essential if they are to be of clinical value. Multivariate statistical models of RL and EL may facilitate the interpretation of lung mechanics measurements in spontaneously breathing infants.
Asunto(s)
Resistencia de las Vías Respiratorias/fisiología , Recien Nacido Prematuro/fisiología , Rendimiento Pulmonar/fisiología , Mecánica Respiratoria/fisiología , Elasticidad , Femenino , Humanos , Recién Nacido , Masculino , Modelos Biológicos , Análisis MultivarianteRESUMEN
AIM: To determine if pulmonary haemorrhage after surfactant treatment increases short and long term morbidity and mortality in neonates weighing <1500 g at birth. METHODS: Neonates weighing <1500 g at birth who developed pulmonary haemorrhage after surfactant treatment were identified from a database. Based on the change in FIO2, pulmonary haemorrhage was classified as mild, moderate, or severe. Controls were matched for birthweight, gestational age, Apgar scores and hospital. Chronic lung disease (CLD) was defined as the need for supplemental oxygen at 36 weeks of corrected gestational age. RESULTS: From January 1990 to May 1994, 94 of 787 (11.9%) neonates treated with surfactant developed pulmonary haemorrhage. Ten were excluded because of incomplete data or lack of controls. Eighty four were included for further analysis; two acceptable matches were found in 75, while only one match was possible in nine. For the pulmonary haemorrhage group, the mean (SD) birthweight was 917 (238) g, gestational age 27 (1.9) weeks. Pulmonary haemorrhage was severe in 39 (46%), moderate in 22 (26%), and mild in 23 (27%). Moderate and severe pulmonary haemorrhage were associated with chronic lung disease or death, OR 4.4 (confidence interval 1.3-15.7) and OR 7.8 (CI 2.6-28), respectively, while mild pulmonary haemorrhage was not, OR 1.8 (CI 0.55-5.8). pulmonary haemorrhage was associated with major intraventricular haemorrhage (IVH), OR 3.1 (CI 1.5-6.4), but not with minor IVH, OR 1.3 (CI 0.6-2. 6). In the survivors who could be assessed at >/=2 years, the differences in neurodevelopmental outcome among the two groups were not significant. CONCLUSIONS: In neonates treated with surfactant moderate and severe pulmonary haemorrhage is associated with an increased risk of death and short term morbidity. Pulmonary haemorrhage does not seem to be associated with increased long term morbidity.
Asunto(s)
Hemorragia/etiología , Recién Nacido de muy Bajo Peso , Enfermedades Pulmonares/etiología , Síndrome de Dificultad Respiratoria del Recién Nacido/tratamiento farmacológico , Tensoactivos/efectos adversos , Estudios de Casos y Controles , Edad Gestacional , Humanos , Recién Nacido , Recien Nacido PrematuroRESUMEN
The objectives of this study were: 1) to perform documented event-monitoring (DEM) for apnea (A, > or = 20 s) and bradycardia (B, < 80 beats per min for > or = 5 s) in premature infants prior to discharge, and 2) to examine the accuracy of nursing documentation (ND) of A and B. Forty-four stable preterm infants, with mean weights and gestational ages at birth (+/- SD) of 1,543 (+/- 365) g, and 30 (+/- 2) weeks, respectively, were studied using DEM for 9 (+/- 2) days prior to discharge. Differences in DEM and ND were analyzed by the z-test for proportions. There were 561 true events recorded by DEM: 56 were As and 505 were Bs. ND revealed 296 events, 190 As and 106 Bs. Of the 56 true As on DEM, only 21 (38%) were correctly reported by ND (P < 0.001, 95% confidence interval (CI) 0.44-0.81). Of the 505 true Bs on DEM, 153 (30%) were correctly reported by ND (P < 0.001, CI 0.63-0.76). When ND was compared with DEM, 174 (59%) of NDs were true events. Of the 106 As on ND, only 21 (20%) were true As on DEM (P < 0.001, CI 0.58-1). Of the 190 Bs on ND, 153 (80%) were true Bs on DEM (P < 0.001, CI 0.13-0.26). ND did not detect 6 of the 33 infants who had significant events on DEM, while 4 of the 11 who had events reported on ND did not have any on DEM. Thus, 10 infants were misclassified by ND (P < 0.01, CI 0.1-0.36). These results indicate that, compared to DEM, ND not only identified significantly fewer true As and Bs, but also misclassified a significant number of infants. We conclude that DEM performed prior to discharge for preterm infants at risk for apnea and bradycardia provides more objective and accurate information than ND.
Asunto(s)
Apnea/diagnóstico , Bradicardia/diagnóstico , Recien Nacido Prematuro , Monitoreo Fisiológico , Femenino , Humanos , Recién Nacido , Masculino , Alta del PacienteRESUMEN
OBJECTIVE: To determine the incidence of complications in low birth weight neonates with surgically inserted central venous catheters (CVCs). STUDY DESIGN: Retrospective chart review of all neonates < or = 1500-gm birth weight from three tertiary care neonatal intensive care units who required CVC insertion. RESULTS: A total of 112 CVCs was inserted in 104 neonates with birth weight of 798 (490 to 1380) gm, age 16 (3 to 179) days, for a duration of 21 (1 to 130) days. The birth weights of 85 neonates were < or = 1000 gm. One or more complications associated with the CVC occurred in 59 patients (57%). Sepsis was the commonest complication, with 43 episodes in 38 patients, at a rate of 14.5 episodes/1000 catheter days. Using regression analysis, sepsis was associated with birth weight, male sex, and the duration for which the CVC remained in place. Five of the nine who developed superior vena cava syndrome and/or pleural effusions died. CONCLUSION: CVCs can provide venous access that is durable. However, in the LBW neonate, and especially in those of < or = 1000 gm, there is a high incidence of associated complications.
Asunto(s)
Cateterismo Venoso Central/efectos adversos , Recién Nacido de Bajo Peso , Sepsis/etiología , Peso al Nacer , Femenino , Humanos , Recién Nacido , Masculino , Análisis de Regresión , Estudios Retrospectivos , Factores de Riesgo , Factores de TiempoRESUMEN
OBJECTIVE: To study the effect of a single dose of exogenous bovine surfactant on oxygen and ventilatory requirements of neonates with early chronic lung disease. STUDY DESIGN: Prospective pilot study. SETTING: Three regional neonatal intensive care units. METHODS: Infants 7 to 30 days old with birth weights less than 1500 g were eligible if they required a fraction of inspired oxygen (FIO2) of more than 0.4, had stable ventilatory requirements for 24 hours before study entry, and showed diffuse haziness on chest radiographs. Those with patent ductus arteriosus or active infection or those receiving steroid therapy were excluded. After treatment with the surfactant, differences in FIO2 and the ventilator efficiency index were analyzed using the Wilcoxon signed rank test. RESULTS: Ten patients were recruited. Median values (range): birth weight, 693 g (530 to 1100 g); gestation, 25 weeks (24 to 27 weeks); and postnatal age at study entry, 13 days (9 to 30 days). The FIO2 decreased significantly between 0 and 1 hour after surfactant administration, from a median (range) of 0.67 (0.47 to 0.88) to 0.39 (0.28 to 0.63). This effect was sustained for 24 hours (median FIO2, 0.36). Although the FIO2 subsequently increased to 0.49 (range, 0.35 to 0.88) at 72 hours, it was significantly lower than that entry before the study. There was a trend toward an increase in the ventilator efficiency index at 24 and 48 hours. CONCLUSIONS: A single dose of surfactant is effective in reducing oxygen requirements in neonates with early chronic lung disease. Surfactant replacement may be useful adjunctive therapy in these neonates.
Asunto(s)
Recién Nacido de Bajo Peso , Enfermedades del Prematuro/terapia , Enfermedades Pulmonares/terapia , Terapia por Inhalación de Oxígeno , Surfactantes Pulmonares/uso terapéutico , Enfermedad Crónica , Humanos , Recién Nacido , Proyectos Piloto , Estudios Prospectivos , Respiración Artificial , Síndrome de Dificultad Respiratoria del Recién Nacido/terapiaRESUMEN
OBJECTIVE: To study the effect of exogenous bovine surfactant on oxygen and ventilatory requirements in neonates with respiratory deterioration due to pulmonary hemorrhage. DESIGN: Retrospective case series. SETTING: Three regional neonatal intensive care units. METHODS: Infants who received surfactant following a clinically significant pulmonary hemorrhage during the time period July 1991 to December 1993 were identified from a database. Infants were excluded if any other cause was found to explain their deterioration. The primary outcome was change in respiratory status following surfactant therapy, as reflected by oxygenation index (OI) and arterial/Alveolar oxygen ratio. Data points were taken as averages of 3 through 6 hours and 0 through 3 hours for the 6 hours before and after surfactant. Differences were analyzed using analysis of variance for repeated measures, with treatment and time as co-variates. RESULTS: Fifteen patients fulfilled inclusion criteria. Median values (range): birth weight, 960 g (595 to 4045); age at pulmonary hemorrhage, 24.4 hours (0.3 to 62); and interval between pulmonary hemorrhage and surfactant therapy, 10 hours (3.7 to 46.5). Mean OI improved from 24.6, at 0 to 3 hours presurfactant, to 8.6 at 3 to 6 hours postsurfactant (P < .001). No patient deteriorated following surfactant therapy. The primary respiratory diagnosis was respiratory distress syndrome (RDS) in 8, meconium aspiration syndrome in 3, and isolated pulmonary hemorrhage in 4. All those with RDS had also received surfactant before their pulmonary hemorrhage. CONCLUSIONS: Exogenous surfactant appears to be useful adjunctive therapy in neonates with a clinically significant pulmonary hemorrhage. Its use for this indication should be further investigated by a randomized controlled trial.
Asunto(s)
Hemorragia/tratamiento farmacológico , Enfermedades Pulmonares/tratamiento farmacológico , Surfactantes Pulmonares/uso terapéutico , Análisis de Varianza , Femenino , Hemorragia/etiología , Hemorragia/fisiopatología , Humanos , Recién Nacido de Bajo Peso , Recién Nacido , Recien Nacido Prematuro , Enfermedades del Prematuro/tratamiento farmacológico , Enfermedades Pulmonares/etiología , Enfermedades Pulmonares/fisiopatología , Masculino , Síndrome de Aspiración de Meconio/complicaciones , Oxígeno/sangre , Respiración con Presión Positiva , Surfactantes Pulmonares/farmacología , Síndrome de Dificultad Respiratoria del Recién Nacido/complicaciones , Estudios Retrospectivos , Resultado del TratamientoRESUMEN
We report on a boy born with complete penoscrotal transposition, normal scrotum, twisted penile shaft with hypoplastic penile urethra, meatal stenosis, normal bladder, and bilateral cystic dysplastic kidneys. The patient died of renal failure at 2.5 months. This is the 13th reported case of complete penoscrotal transposition with normal scrotum. The possible pathogenesis is discussed and the literature is reviewed.
Asunto(s)
Anomalías Múltiples/patología , Pene/anomalías , Escroto/anomalías , Animales , Evolución Biológica , Cardiomiopatía Hipertrófica/congénito , Resultado Fatal , Humanos , Hidronefrosis/congénito , Recién Nacido , Enfermedades Renales Quísticas/congénito , Masculino , Marsupiales/anatomía & histología , Morfogénesis , Pene/embriología , Escroto/embriologíaRESUMEN
Although amantadine hydrochloride has been extensively used for the prevention of influenza A2, few data exist regarding its safety in pregnancy. We report the outcome of a pregnancy during which the mother was treated with amantadine in the first trimester. The infant, born at 29 weeks gestation, has tetralogy of Fallot and tibial hemimelia. Follow-up of the four prospective cases known to date to the Motherisk Program in Toronto did not identify any abnormalities.
Asunto(s)
Anomalías Inducidas por Medicamentos , Amantadina/efectos adversos , Ectromelia/inducido químicamente , Tetralogía de Fallot/inducido químicamente , Tibia/anomalías , Adulto , Femenino , Humanos , Recién Nacido , Embarazo , Primer Trimestre del EmbarazoRESUMEN
We studied 53 newborn babies with congenital syphilis. The common clinical features seen were low birth weight, hepatosplenomegaly, anaemia, jaundice, and symmetrical superficial desquamation of the skin affecting palms and soles. The presence of these clinical signs is highly suggestive of early congenital syphilis. Hydrops fetalis without rhesus or ABO isoimmunisation should always arouse the suspicion of congenital syphilis.