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Biomedical subjects

C L Bose

Publications and source records attributed to C L Bose.

At least 19 recordsLinked to original sources
PubMed2000

Reduced serum amino acid concentrations in infants with necrotizing enterocolitis.

OBJECTIVE: To determine whether premature infants who have necrotizing enterocolitis (NEC) have deficiencies in glutamine (GLN) and arginine (ARG), which are essential to intestinal integrity. STUDY DESIGN: A 4-month prospective cohort study of serum amino acid and urea levels in premature infants was done. Serum amino acid and urea levels were measured by high-pressure liquid chromatography and enzymatic methods, respectively, on samples obtained on days of life 3, 7, 14, and 21. RESULTS: Infants in the control (n = 32) and NEC groups (n = 13) were comparable for birth weight, gestational age, and Apgar scores. NEC began on mean day of life 14.5 (95% CI, day of life 11 to 18). Median values of GLN were 37% to 57% lower in the NEC group on days 7, 14, and 21 compared with those in the control group (P <.05). On days 7 and 14, median values of ARG, GLN, alanine, lysine, ornithine, and threonine were decreased 36% to 67% (P <.05) in the NEC group. Total nonessential amino and total essential amino acids were 35% to 50% lower in the NEC group on days 7 and 14 (P <.05). Infants in the NEC group had significant reductions in GLN and ARG 7 days before the onset of NEC. CONCLUSIONS: Infants who have NEC have selective amino acid deficiencies including reduced levels of GLN and ARG that may predispose to the illness.

Age Factors↗
PubMed1999

Inhaled nitric oxide in premature neonates with severe hypoxaemic respiratory failure: a randomised controlled trial.

BACKGROUND: Inhaled nitric oxide improves oxygenation and lessens the need for extracorporeal-membrane oxygenation in full-term neonates with hypoxaemic respiratory failure and persistent pulmonary hypertension, but potential adverse effects are intracranial haemorrhage and chronic lung disease. We investigated whether low-dose inhaled nitric oxide would improve survival in premature neonates with unresponsive severe hypoxaemic respiratory failure, and would not increase the frequency or severity of intracranial haemorrhage or chronic lung disease. METHODS: We did a double-blind, randomised controlled trial in 12 perinatal centres that provide tertiary care. 80 premature neonates (gestational age < or = 34 weeks) with severe hypoxaemic respiratory failure were randomly assigned inhaled nitric oxide (n=48) or no nitric oxide (n=32, controls). Our primary outcome was survival to discharge. Analysis was by intention to treat. We studied also the rate and severity of intracranial haemorrhage, pulmonary haemorrhage, duration of ventilation, and chronic lung disease at 36 weeks' postconceptional age. FINDINGS: The two groups did not differ for baseline characteristics or severity of disease. Inhaled nitric oxide improved oxygenation after 60 min (p=0.03). Survival at discharge was 52% in the inhaled-nitric-oxide group and 47% in controls (p=0.65). Causes of death were mainly related to extreme prematurity and were similar in the two groups. The two groups did not differ for adverse events or outcomes (intracranial haemorrhage grade 2-4, 28% inhaled nitric oxide and 33% control; pulmonary haemorrhage 13% and 9%; chronic lung disease 60% and 80%). INTERPRETATION: Low-dose inhaled nitric oxide improved oxygenation but did not improve survival in severely hypoxaemic premature neonates. Low-dose nitric oxide in the most critically ill premature neonates does not increase the risk of intracranial haemorrhage, and may decrease risk of chronic lung injury.

Administration, Inhalation↗
PubMed1999

Effect of initial nitric oxide concentration on outcome in infants with persistent pulmonary hypertension of the newborn.

A randomized nonblinded comparison of two treatment groups was performed to determine whether treatment of infants with persistent pulmonary hypertension of the newborn using a continuous 6-ppm dose of inhaled nitric oxide (iNO) changes the likelihood of death or utilization of extracorporeal membrane oxygenation (ECMO) when compared to infants treated with 20 ppm iNO for 4 h followed by 6 ppm. Twenty-nine infants with a gestational age >/=34 weeks and a diagnosis of persistent pulmonary hypertension of the newborn were enrolled during the 3- year study period. The relative risk (20/6 vs. 6 ppm) for treatment with ECMO was 3.11 (p = 0.02), for death it was 2.80 (p = 0.32), and for either death or ECMO it was 3.42 (p = 0. 006). There was no apparent advantage of treatment with a higher dosage of iNO at the initiation of therapy in the reduction of death or utilization of ECMO. These data suggest that a continuous lower dose of iNO results in a comparable improvement in oxygenation as a short exposure of higher dose iNO at the initiation of therapy.

Administration, Inhalation↗
PubMed1999

Population-based study of chronic lung disease in very low birth weight infants in North Carolina in 1994 with comparisons with 1984. The North Carolina Neonatologists Association.

OBJECTIVE: To assess the pulmonary outcomes of very low birth weight (VLBW) infants in North Carolina in 1994 and to compare rates of survival and chronic lung disease (CLD) between 1994 and 1984 (see reference 2). METHODS: Data were collected prospectively by collaborators from all 13 neonatal intensive care units in North Carolina to determine survival and pulmonary outcomes of infants with birth weights of 500 to 1500 g. State vital statistics data were used to confirm completeness of the sample. CLD was defined as oxygen or ventilator therapy at 36 weeks' postmenstrual age (PMA). For comparisons with the 1984 cohort, survival and pulmonary outcomes of infants defined to be at risk for CLD (ventilated >48 hours and survived 30 days) were recorded at 30 days, 3 months, and 6 months of postnatal age. RESULTS: Outcome data were available for 1413 (92%) of the in-state VLBW live births. Of VLBW infants, 224 (15%) died before 48 hours of age. The overall rate of CLD in 1994 at 36 weeks' PMA was 25%. Rates by birth weight group were 57% for 500 to 750 g birth weight (BW), 41% for 751 to 1000 g BW, 19% for 1001 to 1250 g BW, and 8% for 1251 to 1500 g BW. Infants who received ventilator therapy for >48 hours accounted for 89% of the CLD cases. The CLD rate at 36 weeks' PMA in infants weighing 751 to 1500 g was 37% for those ventilated >48 hours versus 5% for those ventilated <48 hours (OR: 7.1; 95% CI: 4.4-11.3). Overall survival in 1994 was significantly higher for infants than in 1984 (78% vs 74%), most notably in infants 500 to 750 g BW (37% vs 24%), and 751 to 1000 g BW (82% vs 65%). When compared with 1984, the CLD rates in those infants defined to be at risk were significantly higher in 1994 at 30 days (68% vs 54%) and at 3 months (24% vs 15%) of postnatal age. For at-risk infants in 1994, there were fewer infants on the ventilator, but more infants on oxygen alone at all measured time points compared with 1984. CONCLUSION: Survival of VLBW infants has improved since 1984. Ventilator therapy for >48 hours remains a significant risk factor for CLD. The incidence of CLD has increased from 1984 to 1994 but has shifted from ventilator to oxygen therapy. bronchopulmonary dysplasia, epidemiology, infant, low birth weight, intensive care units, neonatal statistics, infant mortality, prospective studies.

Chronic Disease↗
PubMed1999

Risk factors for chronic lung disease in the surfactant era: a North Carolina population-based study of very low birth weight infants. North Carolina Neonatologists Association.

OBJECTIVE: To identify risk factors for chronic lung disease (CLD) in a population-based cohort of very low birth weight infants, born in an era of surfactant usage. We specifically investigated the effects of antenatal steroids, nosocomial infection, patent ductus arteriosus (PDA), fluid management, and ventilator support strategies. METHODS: Data were prospectively collected on 1244 infants born in North Carolina in 1994 with birth weights 500 to 1500 g, and treated at 1 of the 13 intensive care nurseries across the state. The outcome of interest was CLD, defined as dependency on supplemental oxygen at 36 weeks' postmenstrual age. Multivariate odds ratios (OR) and 95% confidence intervals (CI) were estimated with logistic regression models. RESULTS: Among 865 survivors to 36 weeks' postmenstrual age, 224 (26%) had CLD. Nosocomial infection (OR: 2.0; 95% CI: 1.4-3.3), fluid intake on day 2 (OR: 1.06 per 10 mL increase; 95% CI: 1.01-1.11), and the need for ventilation at 48 hours of life (OR: 2.2; 95% CI: 1.3-3.7) were associated with an increased risk of CLD. Among infants ventilated at 48 hours, nosocomial infection (OR: 1.64; 95% CI: 1.02-2.62) and PDA (OR: 1.9; 95% CI: 1.2-3.1) were associated with an increased risk. No association was found with antenatal steroid receipt or increased levels of ventilator support. CONCLUSION: This analysis suggests that with widespread use of surfactant, nosocomial infection, PDA, and water balance persist as risk factors for CLD.

Chronic Disease↗
PubMed1998

Effect of telemedicine on health outcomes in 87 infants requiring neonatal intensive care.

OBJECTIVE: This is an evaluation of a telemedicine system for the rapid interpretation of neonatal echocardiograms from a regional, level III neonatal intensive care unit (NICU). The use of telemedicine to support the cardiology needs of NICUs is increasing. However, there is very little published objective information regarding health outcomes or costs resulting from such telemedicine systems. The primary hypothesis tested was that the utilization of a telemedicine system for the interpretation of neonatal echocardiograms reduces the intensive care length of stay of low birthweight (LBW) infants. STUDY DESIGN: All infants who were admitted to neonatal intensive care at New Hanover Regional Medical Center during the first six months of the system were studied by the use of echocardiograms. They were compared with infants who were born in the same period of the previous year. The outcome measures were the intensive care length of stay, rate of transfer to academic medical centers, and mortality rate. RESULTS: A statistically non-significant reduction of 5.4 days in the intensive care length of stay (LOS) of low birthweight infants was observed (p = 0.37). The cost per echocardiogram transmitted was calculated at $33 compared to previous method of sending videotapes via overnight courier. CONCLUSIONS: While the sample size was inadequate to demonstrate improvements in health outcomes, the magnitude of the change and the low costs of the system suggest that this intervention is practical for obtaining rapid diagnostic and treatment support. Larger studies are warranted to confirm these findings and determine whether faster diagnosis and earlier initiation of treatment improve health outcomes of newborn infants.

Academic Medical Centers↗
PubMed1998

The effect of a neonatal telecardiology system on respiratory therapy in very low birthweight infants.

Factors in the U.S. healthcare system have shifted the site of care of many newborns to hospitals where subspecialty services are unavailable. This study examines whether a more rapid turn-around of echocardiogram interpretations and availability of interactive video during neonatal consultations reduces the morbidity of very low birthweight (VLBW) infants. The two groups (n = 21 and n = 28) were similar on the basis of known risk factors. A composite index of respiratory therapy intensivity and duration was used to measure the utilization of respiratory therapies. The index was similar in both groups, 89.6 +/- 12.6 before versus 89.5 +/- 13.0 with telemedicine. These results show little evidence of a reduction in RT utilization.

Cardiology↗
PubMed1995

Double-blind evaluation of developmental and health status to age 2 years of infants weighing 700 to 1350 grams treated prophylactically at birth with a single dose of synthetic surfactant or air placebo.

In a previously published article, we reported results of a two-center study of outcome to 28 days of 385 infants with birth weights from 700 to 1350 gm who were assigned randomly to receive a single 5 ml/kg intratracheal dose of either synthetic surfactant or air placebo. Infants treated with surfactant had a higher rate of survival to 28 days without bronchopulmonary dysplasia than did control subjects given an air placebo. The present study assessed survivors in early childhood to determine neurodevelopmental outcome and late morbidity. Two hundred fifty-eight surviving infants from both centers were evaluated at 1-year adjusted age; medical histories were obtained, standard physical and neurologic examinations were performed, and Bayley Scales of Infant Development were administered. Ophthalmologic examinations were performed at various times between 28 days and 1-year adjusted age. At 2-years adjusted age, 118 infants from one center were reevaluated with the same procedures and also had hearing and speech evaluations. Neither the 1-year assessment of the entire population nor the 2-year assessment of the one center's cohort revealed physical or neurodevelopmental differences between treatment groups. We conclude that administration of a single prophylactic dose of synthetic surfactant to premature infants with birth weights from 700 to 1350 grams results in improved survival rates to 28 days without bronchopulmonary dysplasia and is not associated with adverse health or neurodevelopmental effects at 1-year or 2-years adjusted age.

Air↗
PubMed1995

Administration of granulocyte colony-stimulating factor to neutropenic low birth weight infants of mothers with preeclampsia.

Nine low birth weight infants with neutropenia born to mothers with preeclampsia were treated with granulocyte-colony stimulating factor, 10 micrograms/kg intravenously, within 24 hours of birth and at 24-hour intervals for a maximum of three doses if neutropenia persisted. The absolute neutrophil count increased significantly in eight of the nine infants within 6 hours, and neutrophilia was sustained for at least 72 hours after administration of a single dose of granulocyte-colony stimulating factor.

Female↗
PubMed1995

Effect of L-arginine infusion on infants with persistent pulmonary hypertension of the newborn.

Nitric oxide (NO) is thought to be a primary mediator of the reduction in pulmonary vascular resistance which occurs in the newborn period. L-arginine is the precursor for the formation of nitric oxide in the pulmonary endothelium. Low serum arginine levels have been reported in infants with persistent pulmonary hypertension of the newborn (PPHN). We infused a single L-arginine dose of 500 mg/kg over 30 min to 5 consecutive infants with PPHN. Ninety minutes after infusion we observed an associated rise in PaO2 of 37 to 84 mm Hg and, in 4 of 5 infants, a reduction in oxygenation index (OI) of 33-50% over the 5-hour period following infusion. Infusion was not associated with adverse effects. These observations suggest that L-arginine administration may be an effective therapeutic alternative in infants with PPHN.

Arginine↗
PubMed1989

Risk factors for chronic lung disease in infants with birth weights of 751 to 1000 grams.

We performed a multicenter, historical-cohort analysis to identify factors associated with chronic lung disease (CLD) in extremely low birth weight infants. The 235 infants who were born in 1984 with birth weights of 751 to 1000 gm and admitted to any of 10 participating neonatal intensive care units comprised the study population. We analyzed demographic characteristics, status at birth, severity of acute atelectasis, and early respiratory treatment in relation to CLD, which we defined as having received oxygen at age 30 days. By univariate analysis, CLD was associated with lower gestational age (p less than 0.001), male sex (p = 0.004), more severe acute atelectasis as indicated by a higher roentgenographic score (p less than 0.001), a higher ventilation rate at 96 hours (p = 0.012), and lower PaCO2 at 48 hours (p = 0.04). Infants receiving mechanical ventilation whose highest PaCO2 levels at 48 or 96 hour were less than 40 mm Hg were 1.45 times as likely to develop CLD as those whose highest PaCO2 levels were greater than 50 mm Hg (95% confidence interval 1.04 to 2.01). CLD rates by center were inversely related to mean PaCO2 levels in infants receiving mechanical ventilation at 48 and 96 hours (Spearman rank correlations 0.60 and 0.55; p less than 0.001). A logistic risk model that included sex, PaCO2 at 48 hours, roentgenographic score, gestational age, and race showed only male sex (p = 0.009) and lower PaCO2 at 48 hours (p = 0.04) to be independent predictors of CLD. We conclude that mechanical ventilation that results in PaCO2 levels above the physiologic range may decrease the risk of CLD in extremely low birth weight infants.

Carbon Dioxide↗
PubMed1988

Neonatal back transport: clinical outcomes.

The convalescent course of 55 infants transported from a Level III hospital back to the community hospitals from which they were originally transported was compared with the course of 58 infants who convalesced in the tertiary center nurseries. The events in their prenatal course and acute neonatal course were similar, thus making comparisons of their convalescent course possible. Weight gain was greater among the transported infants for infants with birth weights greater than or equal to 2,000 g and comparable if birth weight was less than 2,000 g. Transported infants received fewer transfusions than their nontransported counterparts. Tolerance of feedings, the occurrence of apnea and bradycardia, and use and discontinuance of supplemental oxygen were similar in both groups. Major new health problems occurred in 27% of all subjects, 20% of transported infants and 32% of nontransported infants. Readmission to the tertiary center or a change in status to more intensive care in the tertiary center occurred in 10% of all infants, 7% of transported and 14% of nontransported infants. It was concluded that convalescing infants often presented new clinical problems, in similar numbers and severity whether convalescing in the tertiary center or after back transport to community hospitals. Community hospital care givers were considered alert to these new problems and to have provided appropriate care, including retransfer to the tertiary center when necessary.

Body Weight↗
PubMed1987

Chronic lung disease in infants with very low birth weight. A population-based study.

We surveyed outcome in 1095 (95.5%) of 1147 very-low-birth-weight infants born in North Carolina in 1984 to determine the incidence of chronic lung disease (CLD) and to learn whether there are differences in incidence among newborn intensive care units (NICUs). At 30 days of age, 39% of surviving infants who had received mechanical ventilation for more than 48 hours were still respirator dependent; 15% were only oxygen dependent. By 3 months, the rates had fallen to 8% and 7%, respectively. By 6 months of age, only 1.6% were respirator dependent but 3% were oxygen dependent and 9% had died. The NICUs differed widely in incidence of CLD, without relation to number of very-low-birth-weight infants treated or to whether treatment was by pediatric residents. Rates of CLD among survivors at 30 days were not inversely related to prior mortality rates. Incidence varied inversely by birth weight, but differences among NICUs were only partly due to differing weight distributions.

Chronic Disease↗
PubMed1986

Rapid mechanical ventilation effects on tracheal airway pressure, lung volume, and blood gases of rabbits.

The purpose of this study was to demonstrate that ventilation of rabbit lungs (whose mechanics are similar to those of human infants) at rapid rates will lead to large alterations in tracheal airway pressures, tidal volume, and functional residual capacity (FRC) with only minor changes in arterial blood gases. Thirteen rabbits were ventilated at rates of 30, 60, 90, and 120 breaths per minutes (BPM) with pressures of 17/2 cm H2O. Tracheal peak inspiratory pressure (PIP) was always lower than ventilator PIP and decreased to 11 +/- 1 cm H2O at 120 BPM. Positive end-expiratory pressure (PEEP) in the trachea was always greater than 2 cm H2O and increased with rate (3.5 cm H2O at 120 BPM). Tidal volume decreased as rates were increased such that rates above 60 BPM resulted in insignificant changes in minute ventilation and arterial blood gases. However, the FRC increased from 16 (30 BPM) to 25 ml/kg (120 BPM), a 56% increase, suggesting large increases in end-expiratory alveolar pressure. We conclude that rapid-rate ventilation (greater than 60 BPM) of healthy rabbits results in significant increases in both tracheal PEEP and FRC without significantly affecting arterial blood gases. The increased tracheal PEEP and FRC are manifestations of inadvertent PEEP. The increased FRC without concomitant increase in PaO2 implicates alveolar overdistention. We speculate that rapid-rate ventilation of human infants having lung mechanics similar to rabbits, will also result in inadvertent PEEP and alveolar overdistention.

Animals↗
PubMed1986

The functional residual capacity of infants with respiratory distress syndrome.

Positive end-expiratory pressure (PEEP) is used in the treatment of infants with respiratory distress syndrome (RDS) to prevent atelectasis, recruit alveolar space and return the functional residual capacity (FRC) toward normal volumes. This study determined the FRC range of 15 prematurely born infants with RDS receiving PEEP. Ventilator settings were controlled clinically using predominantly results of arterial blood-gas analyses. Measurements of arterial blood-gases and FRC (N2 washout) were made during the infants' second day of life. The FRC of the infants on a PEEP of 4.5 +/- 1.3 cmH2O ranged widely from 3 to 33 ml/kg with a mean of 14.5 ml/kg; 17 +/- 2 ml/kg was considered normal. The FRC was within one SD of the mean in only three of the 15 infants (20%) and outside of two SD of normal in seven (47%). A linear regression of calculated alveolar-arterial oxygen gradient (AaDo2) with FRC yielded a correlation coefficient r = 0.825. The AaDo2 values could be used to identify six of the seven infants having FRC outside of 2SD from normal. We conclude that convential methods of PEEP selection for infants with RDS seldom result in a normalization of FRC. Calculated AaDo2 values may be used to identify most RDS infants with FRC widely divergent from normal values.

Functional Residual Capacity↗
PubMed1986

Measurement of cardiopulmonary function in ventilated neonates with respiratory distress syndrome using rebreathing methodology.

The feasibility of using a multiple gas rebreathing technique to evaluate cardiopulmonary function in the ventilated neonate was assessed by measuring functional residual capacity, diffusing capacity of lung for carbon monoxide, and effective pulmonary capillary blood flow in 10 neonates with respiratory distress syndrome. Measurements were first made on the level of positive end expiratory pressure (PEEP) selected by the clinicians caring for the infants ("clinical" PEEP, mean of 4.4 +/- 0.3 cm H2O). To evaluate the effect of PEEP on cardiopulmonary function, PEEP was then changed above (mean of 6.7 +/- 0.4 cm H2O) and below (mean of 1.9 +/- 0.3 cm H2O) this level and measurements were repeated. Mean functional residual capacity on clinical PEEP (10.8 +/- 1.6 ml/kg) was far below the predicted normal and varied directly with changes in PEEP (mean change of 1.2 ml/kg/cm H2O). Diffusing capacity of the lung for carbon monoxide on clinical PEEP was 0.04 +/- 0.01 ml/min/mm Hg/kg and did not change significantly with changes in PEEP. Mean effective pulmonary capillary blood flow was highest (70 ml/min/kg) at the lowest level of PEEP. However, the effect of increasing PEEP on effective pulmonary capillary blood flow in individual infants varied. Increasing PEEP increased arterial oxygen tension but did not cause changes in systemic arterial pressure or heart rate. We conclude that infants with respiratory distress syndrome have severe lung injury with decreased functional residual capacity and diffusing capacity of the lung for carbon monoxide, and that lung volume improves with the use of PEEP.(ABSTRACT TRUNCATED AT 250 WORDS)

Carbon Monoxide↗
PubMed1985

Neonatal back-transport. Cost-effectiveness.

This study examines the cost-effectiveness of returning previously ill neonates to community hospitals after treatment in a tertiary center, a concept known as "back-transport." The authors compared the charges for medical care during convalescence of a group of back-transported infants (BT infants; n = 20) with a similar group of infants who remained in a tertiary center for convalescence (NT infants; n = 20). The total charges for convalescent care (inpatient plus transport charges) for 20 representative BT infants was $61,840, compared with $68,240 for 20 matched NT infants, an average savings of $320 per BT infant. The average daily bed charge and charges for laboratory tests and medications were significantly less for BT infants compared with NT infants, and these reductions offset the transport charges for BT infants. The authors conclude that back transport decreases the charges for medical care for most infants. Therefore, the decision to back-transport an individual infant usually can be based on factors other than cost.

Convalescence↗