RESUMEN
OBJECTIVE: Changes in cerebrovascular hemodynamics associated with head position may be important in the pathogenesis of periventricular-intraventricular hemorrhage (PIVH) in premature infants. This study evaluated the effect of elevated midline head positioning on cardiopulmonary function and the incidence of PIVH. STUDY DESIGN: ELBW infants were randomized to FLAT (flat, supine) or ELEV (supine, bed elevated 30 degrees) for 96 h. Cardiopulmonary function, complications of prematurity, and the occurrence of PIVH were documented. RESULTS: Infants were randomized into FLAT (n = 90) and ELEV groups (n = 90). No significant differences were seen in the incidence of BPD or other respiratory complications. The ELEV group developed significantly fewer grade 4 hemorrhages (p = 0.036) and survival to discharge was significantly higher in the ELEV group (p = 0.037). CONCLUSIONS: Managing ELBW infants in an elevated midline head position for the first 4 days of life appears safe and may decrease the likelihood of severe PIVH and improve survival.
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Hemorragia Cerebral , Ventrículos Cerebrales , Circulación Cerebrovascular/fisiología , Enfermedades del Prematuro , Movimiento y Levantamiento de Pacientes , Posicionamiento del Paciente , Hemorragia Cerebral/diagnóstico , Hemorragia Cerebral/epidemiología , Hemorragia Cerebral/etiología , Hemorragia Cerebral/terapia , Ventrículos Cerebrales/irrigación sanguínea , Ventrículos Cerebrales/diagnóstico por imagen , Femenino , Edad Gestacional , Cabeza , Humanos , Incidencia , Recien Nacido con Peso al Nacer Extremadamente Bajo , Recién Nacido , Enfermedades del Prematuro/diagnóstico , Enfermedades del Prematuro/epidemiología , Enfermedades del Prematuro/etiología , Enfermedades del Prematuro/terapia , Cuidado Intensivo Neonatal/métodos , Masculino , Movimiento y Levantamiento de Pacientes/efectos adversos , Movimiento y Levantamiento de Pacientes/métodos , Posicionamiento del Paciente/efectos adversos , Posicionamiento del Paciente/métodos , Resultado del Tratamiento , Ultrasonografía/métodosRESUMEN
BACKGROUND: Therapeutic hypothermia (HT) is the only intervention that improves outcomes in neonatal hypoxic-ischemic encephalopathy (HIE). However, the multifactorial mechanisms by which HT impacts HIE are incompletely understood. The complement system plays a major role in the pathogenesis of ischemia-reperfusion injuries such as HIE. We have previously demonstrated that HT modulates complement activity in vitro. METHODS: Term equivalent rat pups were subjected to unilateral carotid ligation followed by hypoxia (8% O2) for 45 min to simulate HIE. A subset of animals was subjected to HT (31-32°C for 6 h). Plasma and brain levels of C3a and C5a were measured. Receptors for C3a (C3aR) and C5a (C5aR) along with C1q, C3, and C9 were characterized in neurons, astrocytes, and microglia. RESULTS: We found that HT increased systemic expression of C3a and decreased expression of C5a after HIE. In the brain, C3aR and C5aR are predominantly expressed on microglia after HIE. HT increased local expression of C3aR and decreased expression on C5aR after HIE. Furthermore, HT decreased local expression of C1q, C3-products, and C9 in the brain. CONCLUSION: HT is associated with significant alteration of complement effectors and their cognate receptors. Complement modulation may improve outcomes in neonatal HIE.
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Encefalopatías/sangre , Complemento C3a/análisis , Complemento C5a/análisis , Hipotermia Inducida , Hipoxia-Isquemia Encefálica/sangre , Animales , Animales Recién Nacidos , Astrocitos/metabolismo , Encéfalo/patología , Encefalopatías/terapia , Hipoxia , Hipoxia-Isquemia Encefálica/terapia , Microglía/metabolismo , Neuronas/metabolismo , Ratas , Ratas Wistar , Daño por Reperfusión , Temperatura , Factores de TiempoRESUMEN
A three group prospective randomized experimental design was conducted to identify differences in frequency and severity of nasal injuries when comparing various interfaces used during continuous positive airway pressure (CPAP) and identified risk factors associated with injury. Seventy-eight neonates <1500 g were randomized into three groups: continuous nasal prongs; continuous nasal mask; or alternating mask/prongs. Repeated measures ANOVA with Bonferroni correction demonstrated that significantly less skin injury was detected in the rotation interface group when compared to both mask and prong groups. In the final stepwise regression model (F = 11.51; R(2) = 0.221; p = 0.006) significant predictors of skin injury included number of days on nasal CPAP (p < 0.001) and current mean post menstrual age (p = 0. 006). Reduced nasal injury was demonstrated using rotating mask/prong nasal interfaces. Future best practices must include precise selection of device size, developmental and CPAP device positioning with focused skin assessment including rapid intervention for skin injury.
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Presión de las Vías Aéreas Positiva Contínua/efectos adversos , Recién Nacido de muy Bajo Peso , Nariz/lesiones , Piel/lesiones , Presión de las Vías Aéreas Positiva Contínua/instrumentación , Humanos , Recién Nacido , Estudios Prospectivos , Factores de RiesgoRESUMEN
BACKGROUND: Therapeutic hypothermia (HT) has been shown to decrease death and severe disability in infants with hypoxic-ischemic encephalopathy (HIE). Rectal temperature (RT) is used to determine the temperature set-points for treatment with HT, however experimental studies have shown significant differences between RT and brain temperature during HT. Knowledge of actual brain temperature during HT might allow better determination of optimal degree of cooling and improve outcomes. OBJECTIVES: To compare measurements of brain temperature obtained by non-invasive radiometric thermometry (RadT) to direct tissue measurements in an experimental model of HT, and to use RadT in newborn infants with HIE undergoing HT. STUDY DESIGN: RadT measurements of brain temperature were compared to fiber optic (Luxtron) thermometry measurements placed at a depth of 1.5 centimeters into the brain of cooled miniswine. Following validation studies, brain RadT and RT measurements were continuously recorded in thirty infants with HIE during HT and rewarming. RESULTS: RadT and Luxtron probe temperatures were comparable in miniswine throughout a temperature range similar to therapeutic HT. RadT measurements of brain temperature were higher than RT in 60% of infants with HIE undergoing HT. Higher RadT measurements compared to RT were associated with cerebral white matter abnormalities (p = 0.01). CONCLUSIONS: RadT provides a safe, passive and non-invasive way to measure brain temperature that can be used in the clinical setting. RadT may be helpful in determining the optimal degree of cooling and identifying infants at highest risk of brain injury.
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Asfixia Neonatal/fisiopatología , Temperatura Corporal/fisiología , Hipoxia-Isquemia Encefálica/fisiopatología , Animales , Modelos Animales de Enfermedad , Humanos , Hipotermia Inducida/métodos , Hipoxia-Isquemia Encefálica/terapia , Recién Nacido , Imagen por Resonancia Magnética/métodos , Porcinos , Termometría/métodosRESUMEN
Capnocytophaga is an opportunistic gram-negative anaerobic bacillus found in the oropharyngeal cavity of mammals and is associated with periodontal disease in humans. Sepsis, osteomyelitis, lung abscess, endocarditis, and meningitis have been reported in humans following animal bites. Perinatal infection with Capnocytophaga is infrequent and is generally considered to have a low risk of morbidity to the mother and fetus. We report a case of neonatal Capnocytophaga sepsis associated with the development of severe cystic periventricular leukomalacia.
RESUMEN
OBJECTIVE: To identify factors associated with skin injury during nasal continuous positive airway pressure (NCPAP) and describe differences in frequency, severity, and type of skin injuries when comparing nasal interfaces used during NCPAP in the preterm infant. DATA SOURCES: Scientific databases were searched using provided key terms and yielded 113 articles. STUDY SELECTION: Forty-six articles were included in this integrative review: six case studies, 22 with identified aim of examining skin and nasal injury during NCPAP; 18 included skin care considerations during NCPAP. DATA EXTRACTION: Studies were categorized into four themes: types of nasal injuries; associated risk factors that increase incidence of injury; differences between NCPAP devices and/or nasal interface and corresponding rate and severity of nasal injury; and recommended prevention strategies to reduce iatrogenic cutaneous injury. DATA SYNTHESIS: Skin injury was a common theme during neonatal NCPAP with skin breakdown rates of 20% to 60%. Increased skin injury risk was associated with smaller infant size, gestational age, and duration of therapy. Nursing care strategies to improve skin integrity during NCPAP had little supportive evidence. Nursing practice is varied with reportedly little standardized care during NCPAP therapy. Recommendations for specific care strategies to reduce skin injury during NCPAP were supported by limited experimental studies. CONCLUSIONS: Risk factors during NCPAP include nasal injury and trauma secondary to tight-fitting nasal interfaces necessary to provide continuous distending pressure for respiratory stability. Identifying strategies to reduce skin breakdown will support noninvasive treatment success, reduce reintubation rates, reduce sepsis, reduce patient discomfort, and improve developmental outcomes during NCPAP use.
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Presión de las Vías Aéreas Positiva Contínua/efectos adversos , Recien Nacido Prematuro , Síndrome de Dificultad Respiratoria del Recién Nacido/terapia , Enfermedades de la Piel/fisiopatología , Piel/lesiones , Presión de las Vías Aéreas Positiva Contínua/métodos , Femenino , Humanos , Recién Nacido , Masculino , Monitoreo Fisiológico/métodos , Mucosa Nasal/lesiones , Síndrome de Dificultad Respiratoria del Recién Nacido/diagnóstico , Medición de Riesgo , Enfermedades de la Piel/etiología , Resultado del TratamientoRESUMEN
OBJECTIVES: To determine systemic hypothermia's effect on circulating immune cells and their corresponding chemokines after hypoxic ischemic encephalopathy in neonates. DESIGN: In our randomized, controlled, multicenter trial of systemic hypothermia in neonatal hypoxic ischemic encephalopathy, we measured total and leukocyte subset and serum chemokine levels over time in both hypothermia and normothermia groups, as primary outcomes for safety. SETTING: Neonatal ICUs participating in a Neurological Disorders and Stroke sponsored clinical trial of therapeutic hypothermia. PATIENTS: Sixty-five neonates with moderate to severe hypoxic ischemic encephalopathy within 6 hours after birth. INTERVENTIONS: Patients were randomized to normothermia of 37°C or systemic hypothermia of 33°C for 48 hours. MEASUREMENTS AND MAIN RESULTS: Complete and differential leukocyte counts and serum chemokines were measured every 12 hours for 72 hours. The hypothermia group had significantly lower median circulating total WBC and leukocyte subclasses than the normothermia group before rewarming, with a nadir at 36 hours. Only the absolute neutrophil count rebounded after rewarming in the hypothermia group. Chemokines, monocyte chemotactic protein-1 and interleukin-8, which mediate leukocyte chemotaxis as well as bone marrow suppression, were negatively correlated with their target leukocytes in the hypothermia group, suggesting active chemokine and leukocyte modulation by hypothermia. Relative leukopenia at 60-72 hours correlated with an adverse outcome in the hypothermia group. CONCLUSIONS: Our data are consistent with chemokine-associated systemic immunosuppression with hypothermia treatment. In hypothermic neonates, persistence of lower leukocyte counts after rewarming is observed in infants with more severe CNS injury.
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Quimiocinas/sangre , Hipotermia Inducida , Hipoxia-Isquemia Encefálica/sangre , Hipoxia-Isquemia Encefálica/terapia , Leucocitos/fisiología , Femenino , Humanos , Lactante , Recién Nacido , Unidades de Cuidado Intensivo Neonatal , Recuento de Leucocitos , Masculino , Factores de Tiempo , Resultado del TratamientoRESUMEN
Inflammatory cytokines may mediate hypoxic-ischemic (HI) injury and offer insights into the severity of injury and the timing of recovery. In our randomized, multicenter trial of hypothermia, we analyzed the temporal relationship of serum cytokine levels in neonates with hypoxic-ischemic encephalopathy (HIE) with neurodevelopmental outcome at 12 months. Serum cytokines were measured every 12 hours for 4 days in 28 hypothermic (H) and 22 normothermic (N) neonates with HIE. Monocyte chemotactic protein-1 (MCP-1) and interleukins (IL)-6, IL-8, and IL-10 were significantly higher in the H group. Elevated IL-6 and MCP-1 within 9 hours after birth and low macrophage inflammatory protein 1a (MIP-1a) at 60 to 70 hours of age were associated with death or severely abnormal neurodevelopment at 12 months of age. However, IL-6, IL-8, and MCP-1 showed a biphasic pattern in the H group, with early and delayed peaks. In H neonates with better outcomes, uniform down modulation of IL-6, IL-8, and IL-10 from their peak levels at 24 hours to their nadir at 36 hours was observed. Modulation of serum cytokines after HI injury may be another mechanism of improved outcomes in neonates treated with induced hypothermia.
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Citocinas/sangre , Hipotermia Inducida , Hipoxia-Isquemia Encefálica/sangre , Hipoxia-Isquemia Encefálica/terapia , Encéfalo/irrigación sanguínea , Quimiocina CCL2/sangre , Quimiocina CCL3/sangre , Femenino , Humanos , Hipoxia-Isquemia Encefálica/diagnóstico , Lactante , Recién Nacido , Interleucina-12/sangre , Interleucina-6/sangre , Masculino , Pronóstico , Factores Sexuales , Factores de Tiempo , Resultado del TratamientoRESUMEN
Cutaneous manifestations of congenital herpes simplex virus (HSV) have been classically described as grouped vesicles on an erythematous base. We report two cases of HSV infection wherein both infants presented at birth with widespread erosions and an absence of vesicles or vesicopustules. The presence of skin lesions at birth, neurologic changes seen on radiographic imaging, and a cesarean section delivery in one case suggests intrauterine transmission in both neonates.
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Herpes Simple/patología , Herpes Simple/transmisión , Transmisión Vertical de Enfermedad Infecciosa , Piel/patología , Biopsia , Diagnóstico Diferencial , Femenino , Herpes Simple/congénito , Humanos , Recién Nacido , Masculino , NecrosisRESUMEN
Proinflammatory cytokines have been variably linked to development of cerebral white matter injury (WMI) in preterm infants. Because soluble receptors tightly control cytokine bioactivity, we modeled cytokine-receptor interaction as a predictor of WMI. Plasma from 100 preterm infants was assayed for cytokines (tumor necrosis factor alpha, interleukin (IL-1beta, IL-6) and their soluble receptors (sTNF-RI), sTNF-RII, sIL-1RA, and sIL-6R). Cranial ultrasound (US) results were correlated with cytokine and receptor concentrations individually and with cytokine-receptor interaction models (PROC LOGISTIC; SAS Software). Receiver operating characteristic curves were constructed to determine the predictability of WMI. Fifty-two infants with normal US exams were compared with 21 infants with evidence of WMI. There was no association between individual cytokine or receptor concentrations and the development of WMI. However, modeling cytokines with their soluble receptors significantly improved the predictability of WMI. We concluded that consideration of cytokine-receptor interaction may be more important than individual cytokine concentrations alone in determining the role of inflammation in the pathogenesis of WMI in preterm infants.
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Citocinas/sangre , Enfermedades del Prematuro/sangre , Recién Nacido de muy Bajo Peso , Leucomalacia Periventricular/sangre , Receptores de Interleucina/sangre , Receptores del Factor de Necrosis Tumoral/sangre , Biomarcadores/sangre , Encéfalo , Ecoencefalografía , Femenino , Humanos , Recién Nacido , Recien Nacido Prematuro , Enfermedades del Prematuro/diagnóstico , Enfermedades del Prematuro/diagnóstico por imagen , Interleucina-1beta/sangre , Interleucina-6/sangre , Leucomalacia Periventricular/diagnóstico , Leucomalacia Periventricular/diagnóstico por imagen , Masculino , Factor de Necrosis Tumoral alfa/sangreRESUMEN
Therapeutic hypothermia holds promise as a rescue neuroprotective strategy for hypoxic-ischemic injury, but the incidence of severe neurologic sequelae with hypothermia is unknown in encephalopathic neonates who present shortly after birth. This study reports a multicenter, randomized, controlled, pilot trial of moderate systemic hypothermia (33 degrees C) vs normothermia (37 degrees C) for 48 hours in neonates initiated within 6 hours of birth or hypoxic-ischemic event. The trial tested the ability to initiate systemic hypothermia in outlying hospitals and participating tertiary care centers, and determined the incidence of adverse neurologic outcomes of death and developmental scores at 12 months by Bayley II or Vineland tests between normothermic and hypothermic groups. Thirty-two hypothermic and 33 normothermic neonates were enrolled. The entry criteria selected a severely affected group of neonates, with 77% Sarnat stage III. Ten hypothermia (10/32, 31%) and 14 normothermia (14/33, 42%) patients expired. Controlling for treatment group, outborn infants were significantly more likely to die than hypoxic-ischemic infants born in participating tertiary care centers (odds ratio 10.7, 95% confidence interval 1.3-90). Severely abnormal motor scores (Psychomotor Development Index < 70) were recorded in 64% of normothermia patients and in 24% of hypothermia patients. The combined outcome of death or severe motor scores yielded fewer bad outcomes in the hypothermia group (52%) than the normothermia group (84%) (P = 0.019). Although these results need to be validated in a large clinical trial, this pilot trial provides important data for clinical trial design of hypothermia treatment in neonatal hypoxic-ischemic injury.
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Hipotermia Inducida , Hipoxia-Isquemia Encefálica/mortalidad , Hipoxia-Isquemia Encefálica/terapia , Desarrollo Infantil , Cognición , Evaluación de la Discapacidad , Femenino , Estudios de Seguimiento , Humanos , Incidencia , Lactante , Recién Nacido , Masculino , Actividad Motora , Proyectos Piloto , Resultado del TratamientoRESUMEN
Hypoxic-ischemic injury may cause multisystem organ damage with significant aberrations in clotting, renal, and cardiac functions. Systemic hypothermia may aggravate these medical conditions, such as bradycardia and increased clotting times, and very little safety data in neonatal hypoxic-ischemic injury is available. This study reports a multicenter, randomized, controlled pilot trial of moderate systemic hypothermia (33 degrees C) vs normothermia (37 degrees C) for 48 hours in infants with neonatal encephalopathy instituted within 6 hours of birth or hypoxic-ischemic event. The best outcome measures of safety were determined, comparing rates of adverse events between normothermia and hypothermia groups. A total of 32 hypothermia and 33 normothermia neonates were enrolled in seven centers. Adverse events and serious adverse effects were collected by the study team during the hospital admission, monitored by an independent study monitor, and reported to Institutional Review Boards and the Data and Safety Monitoring Committee. The following adverse events were observed significantly more commonly in the hypothermia group: more frequent bradycardia and lower heart rates during the period of hypothermia, longer dependence on pressors, higher prothrombin times, and lower platelet counts with more patients requiring plasma and platelet transfusions. Seizures as an adverse event were more common in the hypothermia group. These observed side effects of 48 hours of moderate systemic hypothermia were of mild to moderate severity and manageable with minor interventions.
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Hipotermia Inducida/efectos adversos , Hipoxia-Isquemia Encefálica/terapia , Acidosis/epidemiología , Acidosis/etiología , Trastornos de la Coagulación Sanguínea/epidemiología , Trastornos de la Coagulación Sanguínea/etiología , Bradicardia/epidemiología , Bradicardia/etiología , Femenino , Hematuria/epidemiología , Hematuria/etiología , Humanos , Hipertensión Pulmonar/epidemiología , Hipertensión Pulmonar/etiología , Hipoxia-Isquemia Encefálica/epidemiología , Lactante , Recién Nacido , Masculino , Proyectos Piloto , Factores de Riesgo , Seguridad , Trombocitopenia/epidemiología , Trombocitopenia/etiología , Resultado del TratamientoRESUMEN
Recent reports suggest that learning is enhanced by emotion, spontaneity, and play. The mechanisms of this enhancement are unclear and might involve increased cortical stimulation by the limbic system. Since neuronal activity is tightly coupled to changes in cerebral blood flow and volume, the demonstration of increased cortical blood volume during playful versus routine motor and somatosensory activity would imply enhanced neuronal activity and provide insight into the complex interaction between play and learning. Near-infrared spectroscopy was used to detect changes in cortical blood volume during performance of (1) rudimentary visual, motor, and speech tasks; (2) integration of the tasks in a familiar routine manner; and (3) integration of the tasks in a novel, spontaneous, playful manner. No significant differences in cortical blood volume were found during the performance of the individual rudimentary tasks and their routine integration. However, the novel integration activity was associated with a significantly greater increase in frontal lobe oxyhemoglobin, deoxyhemoglobin, and total hemoglobin, as well as parietal lobe total hemoglobin. This small pilot study provides a limited measure of physiologic support for a relationship between play and learning.
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Mapeo Encefálico , Corteza Cerebral/irrigación sanguínea , Juego e Implementos de Juego , Adulto , Niño , Humanos , Aprendizaje , Masculino , Persona de Mediana Edad , Actividad Motora , Flujo Sanguíneo Regional , Espectroscopía Infrarroja Corta , Habla , Análisis y Desempeño de Tareas , Percepción VisualAsunto(s)
Trastornos del Espectro Alcohólico Fetal , Discapacidades del Desarrollo/etiología , Diagnóstico Diferencial , Femenino , Trastornos del Espectro Alcohólico Fetal/diagnóstico , Trastornos del Espectro Alcohólico Fetal/epidemiología , Trastornos del Espectro Alcohólico Fetal/etiología , Trastornos del Espectro Alcohólico Fetal/prevención & control , Trastornos del Crecimiento/etiología , Educación en Salud , Humanos , Incidencia , Recién Nacido , Madres/educación , Madres/psicología , Evaluación de Necesidades , Embarazo , Apoyo Social , Estados Unidos/epidemiologíaRESUMEN
Premature very-low-birth-weight infants with posthemorrhagic hydrocephalus are often managed with intermittent cerebrospinal fluid drainage from a ventricular reservoir. There are little data regarding intracranial pressure changes during intermittent drainage to determine the amount and frequency of cerebrospinal fluid removal or to determine the correct resistance of future programmable shunts. The objective of this study was to determine the feasibility of using a commercially available intracranial pressure transducer to measure changes in pressure associated with this procedure. Continuous intracranial pressure was measured in three infants with a transducer placed at the time of ventricular reservoir insertion. Daily reservoir taps began 48 hours after placement and intracranial pressure was monitored for 7 days. Intracranial pressure before the initial tap was comparable to levels previously reported as normal. The daily removal of 10 cc/kg of cerebrospinal fluid was sufficient to lower intracranial pressure below baseline, however it was associated with wide swings in pressure and, in one patient, sustained negative pressure. The use of direct intracranial pressure monitoring may be useful in determining the optimal amount and frequency of cerebrospinal drainage from infants with posthemorrhagic hydrocephalus managed with a ventricular reservoir, as well as determining resistance settings of subsequent programmable shunts.
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Derivaciones del Líquido Cefalorraquídeo/métodos , Hidrocefalia/líquido cefalorraquídeo , Presión Intracraneal/fisiología , Derivaciones del Líquido Cefalorraquídeo/instrumentación , Drenaje/instrumentación , Drenaje/métodos , Femenino , Humanos , Hidrocefalia/terapia , Recién Nacido , Recién Nacido de muy Bajo Peso/líquido cefalorraquídeo , Masculino , Trabajo de Parto Prematuro/líquido cefalorraquídeo , Trabajo de Parto Prematuro/terapia , Proyectos Piloto , Embarazo , Transductores de PresiónAsunto(s)
Lesiones Encefálicas/complicaciones , Infarto Cerebral/etiología , Parálisis Cerebral/etiología , Enfermedades del Prematuro/etiología , Leucomalacia Periventricular/etiología , Gemelos , Lesiones Encefálicas/terapia , Infarto Cerebral/terapia , Parálisis Cerebral/terapia , Preescolar , Discapacidades del Desarrollo/etiología , Discapacidades del Desarrollo/terapia , Humanos , Lactante , Recién Nacido , Enfermedades del Prematuro/terapia , Leucomalacia Periventricular/terapia , MasculinoRESUMEN
OBJECTIVE: To examine potential differences in clinical risk factors, including indices of hemodynamic and respiratory functions, of premature infants developing periventricular hemorrhagic infarction (PHI) or periventricular leukomalacia (PVL). STUDY DESIGN: Indices of hemodynamic stability and respiratory function were measured prospectively during the first week of life in a cohort of 100 premature infants with respiratory distress. Maternal history was retrospectively reviewed. These data were correlated with cranial ultrasonography using one-way ANOVA, Bonferroni multiple comparisons, and Wilcoxon rank sum tests. Longitudinal analysis was performed using Generalized Estimating Equations. RESULTS: Fifty-two infants with normal cranial ultrasound studies were compared to 12 with PHI and 9 with PVL. Infants developing PHI had significantly lower birth weights, lower Apgar scores, were more often male and multiple gestations, and required more vasopressor support than infants with normal ultrasound studies. Infants with PHI had significantly worse indices of respiratory function than either normal infants or those with PVL. PVL was significantly associated with maternal chorioamnionitis, whereas PHI was not. CONCLUSION: These data suggest that there are important differences in the pathogenesis of PHI and PVL. A clear understanding of these differences is required before future preventive strategies can be formulated.