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Biomedical subjects

R A Stoddard

Publications and source records attributed to R A Stoddard.

10 recordsLinked to original sources
PubMed2006

Low blood neutrophil concentrations among extremely low birth weight neonates: data from a multihospital health-care system.

OBJECTIVE: A blood neutrophil concentration < 1000/microl has been reported to occur in about 8% of neonatal intensive care unit (NICU) patients, at some time during their hospital stay. However, the incidence of this finding among extremely low birth weight (ELBW) neonates (< 1000 g birth weight) is not known. Using data from four NICU's in one health-care system, we sought to estimate the incidence, timing, causes, severity and duration of neutrophil counts < 1000/microl among ELBW neonates. We also tabulated the treatments used for this condition and associations with mortality. METHODS: We performed an historic cohort analysis of all ELBW neonates born during the 36-month period, 1 July 2002 to 30 June 2005, cared for in the four Intermountain Healthcare level III NICU's. RESULTS: Three hundred and thirty-eight ELBW neonates were the subjects of the analysis. Complete blood cell counts (CBCs) were obtained in all (range, 1 to 123 CBCs/patient). Thirty-eight percent (128/338) had one or more neutrophil counts < 1000/microl. In 57% the low neutrophil count persisted for < 24 h; in 43% it persisted for 1 to 7.5 days. Most of the cases (74%) were detected during the first 3 days of life. Twenty-two percent of cases were not detected until after the first week. Low neutrophil counts were more common among the smallest patients, with a 63% incidence in those < or = 500 g, 44% in those 501 to 600 g and 34% in those 801 to 999 g. When low neutrophil counts were recognized during the first 3 days of life, the patients were typically either small for gestational age (SGA; weight < 10th percentile for gestational age) or born after pregnancy-induced hypertension (PIH) (68%), or had early-onset bacterial infection (6%). When recognized after the first 3 days, the patients typically had necrotizing enterocolitis (31%) or a nosocomial bacterial infection (19%). Alloimmune mechanisms were not tested for in any of the cases. No cause for the low counts was identified among 35% of the neutropenic patients. Intravenous immunoglobulins was administered to 28% of cases, and 100% of these were given according to our written guidelines. Recombinant granulocyte-colony stimulating factor was administered to 13% of cases, and 69% of these were given according to guidelines. Neither the presence of low neutrophil counts nor the severity (lowest recorded count) correlated with mortality rate, except in proven early-onset sepsis. CONCLUSIONS: We observed low neutrophil counts among ELBW neonates at a rate five times that reported in the general NICU population. Most cases were present in the first days of life and occurred in SGA neonates or those with PIH. In over 1/3, no cause was discovered. We maintain that more consistency is needed in evaluating and treating neutropenia among ELBW neonates.

Cohort Studies↗
PubMed2006

Thrombocytopenia among extremely low birth weight neonates: data from a multihospital healthcare system.

OBJECTIVES: Thrombocytopenia is common in neonatal intensive care units (NICU), with 18 to 35% of patients developing this problem before hospital discharge. It might be even more common among extremely low birth weight neonates (ELBW, < or = 1000 g birth weight). However, little is known about thrombocytopenia in the ELBW population. We sought to determine the incidence, timing, causes, platelet transfusions given, and outcomes of thrombocytopenia among ELBW neonates. STUDY DESIGN: We performed a cohort analysis of all 284 ELBW neonates born during 2003 and 2004 cared for in any of the Intermountain Healthcare level III NICUs. RESULTS: Multiple platelet counts were obtained in all 284 (range, 4 to 441 platelet counts/patient). Of the 284, 208 (73%) had one or more platelet counts < or =150 000/microl. Most were detected during the first days of life; 80% were detected during the first week and only 20% were detected thereafter. Thrombcytopenia was more common among the smallest patients; 85% incidence among those < or =800 g, 60% among those 801 to 900 g, and 53% among those 901 to 1000 g. Platelet transfusions were given to 129 of the 208 thrombocytopenic neonates. More than 90% were given prophylactically (the patient was not bleeding). The mortality rate among those that received platelet transfusions was twice that of those that received no platelet transfusions (P < 0.01). In 48% of cases, the cause of the thrombocytopenia went undiagnosed. The most common explanations were being small for gestational age or delivered to a hypertensive mother, DIC, bacterial infection, fungal infection, and necrotizing enterocolitis, respectively. CONCLUSIONS: We observed thrombocytopenia among ELBW neonates at a rate more than twice that reported among the general NICU population. Much remains to be discovered about the etiology and best treatments of thrombocytopenia among ELBW neonates.

Cohort Studies↗
PubMed2001

Childhood outcome after early high-frequency oscillatory ventilation for neonatal respiratory distress syndrome.

OBJECTIVE: In a previous multicenter controlled clinical trial, we randomly assigned surfactant-treated premature newborns with moderate to severe respiratory distress syndrome to early treatment with high-frequency oscillatory ventilation (HFOV) or to conventional ventilation (CV). Compared with control infants who were treated with CV, neonates who were treated with HFOV using a strategy designed to recruit and maintain lung volume and minimize oxygen exposure had clinical evidence of improved pulmonary outcome and less lung injury. We report a follow-up study designed to determine whether clinical differences persisted between these study groups. METHODS: Patients were recruited from 81 survivors at 1 center (Provo, Utah) and evaluated for sociodemographic and health history, growth, mental development, motor proficiency, and pulmonary function. RESULTS: Eighty-seven percent of the cohort who originally were assigned to treatment with HFOV (n = 36) or CV (n = 33) were seen in follow-up at a mean age of 77 months (6.4 years). There were no differences in the frequency of hospitalization, pulmonary illness, asthma, or disabilities. Growth, verbal IQ, and motor development were appropriate for age and not different between groups. Patients who initially were randomized to treatment with CV showed pulmonary function evidence of decreased peak expiratory flow, increased residual lung volume, and maldistribution of ventilation. CONCLUSION: Neurodevelopmental childhood outcome after early intervention HFOV was normal and not different compared with patients who were treated with CV. Surfactant replacement combined with early HFOV using a lung recruitment strategy ameliorates the acute lung injury in respiratory distress syndrome that predisposes some preterm infants to develop chronic lung disease.

Child↗
PubMed1998

Ontogeny of humoral immunity in northern elephant seal (Mirounga angustirostris) neonates.

Northern elephant seal (NES) serum concentrations of total immunoglobulin (Ig) G, an IgG sub-class, and an IgM-like protein were determined by capture immunoassay using three monoclonal antibodies with specificities for Ig of members of the Phocidae pinniped family. These assays were calibrated for use with NES sera using affinity column purified Ig. Concentrations of these Ig populations were estimated in adult female sera sampled at two time points during the lactation period, as well as sera from their pups collected during the first 5 weeks after birth. In pups, concentrations of the IgM-like protein was found to increase rapidly post-partum. In some individuals, values reached mean concentrations within 10-14 days. In addition, rapid increases in pup total IgG and IgG sub-class concentrations were also observed. Collectively, these findings suggest that the majority of post-partum increases in serum Ig can be accounted for by de-novo synthesis.

Age Factors↗
PubMed1996

The Provo multicenter early high-frequency oscillatory ventilation trial: improved pulmonary and clinical outcome in respiratory distress syndrome.

OBJECTIVE: To compare the hospital course and clinical outcome of preterm infants with respiratory distress syndrome treated with surfactant and managed with high-frequency oscillatory ventilation (HFOV) or conventional mechanical ventilation (CV) as their primary mode of ventilator support. DESIGN: A prospective randomized clinical trial. SETTING: Three community-based level III neonatal intensive care units. SUBJECTS: A total of 125 neonates who were 35 weeks or less estimated gestation requiring intubation and assisted ventilation for respiratory distress syndrome with arterial to alveolar oxygen ratio less than .50. INTERVENTIONS: Patients were randomized to continue CV (61 patients) or be changed to HFOV (64 patients) after exogenous surfactant administration (100 mg/kg). HFOV was used in a strategy to promote lung recruitment and maintain lung volume. Protocol respiratory care guidelines were followed; otherwise routine care was provided by each neonatal intensive care unit. MEASUREMENTS AND MAIN RESULTS: No differences were noted in demographic features between the two study groups. The study population birth weight was 1.51 +/- .47 kg (mean +/- SD), gestational age was 30.9 +/- 2.5 weeks, and study entry age was 2 to 3 hours. Patients randomized to HFOV demonstrated the following significant findings compared with CV-treated patients: vasopressor support was less intensive; surfactant redosing was not as frequent; oxygenation improved more rapidly and remained higher during the first 7 days; fewer infants required prolonged supplemental oxygen or ventilator support; treatment failure was reduced; more patients survived without chronic lung disease at 30 days; need for continuous supplemental oxygen at discharge was less; frequency of necrotizing enterocolitis illness was lower; there were fewer abnormal hearing tests; and hospital costs were decreased. No differences were seen between the two study groups in the frequency or severity of patent ductus arteriosus, air leak, retinopathy of prematurity, or intraventricular hemorrhage. Length of hospital stay and survival to discharge were similar for HFOV- and CV-treated infants. CONCLUSIONS: When used early with a lung recruitment strategy, HFOV after surfactant replacement resulted in clinical outcomes consistent with a reduction in both acute and chronic lung injury. Benefit was evident for preterm infants both less than or equal to 1 kg and more than 1 kg. In addition, early HFOV treatment may have had a more global effect on patient health throughout the hospitalization, resulting in reduced morbidity and decreased health care cost.

Equipment Failure↗
PubMed1988

In utero ischemic injury: sonographic diagnosis and medicolegal implications.

The antenatal diagnosis of fetal neurologic injury has profound medical and legal implications. We report a case of antenatally diagnosed intracranial lesions including parenchymal hemorrhage in an otherwise physically normal infant. Computerized tomography in the newborn period demonstrated diffused ischemic damage with secondary cystic changes in addition to intracranial hemorrhage.

Cerebral Hemorrhage↗