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Biomedical subjects

R L Ariagno

Publications and source records attributed to R L Ariagno.

At least 37 records · Page 2Linked to original sources
PubMed1991

A controlled trial of aerosolized ribavirin in infants receiving mechanical ventilation for severe respiratory syncytial virus infection.

BACKGROUND: Although the antiviral agent ribavirin improves the course of lower respiratory tract disease in spontaneously breathing infants with respiratory syncytial virus infection, it is not known whether ribavirin can benefit infants with severe respiratory syncytial virus disease who require mechanical ventilation. METHODS: We conducted a randomized, double-blind, placebo-controlled evaluation of ribavirin (20 mg per milliliter) administered continuously in aerosolized form to infants receiving mechanical ventilation for respiratory failure that was caused by documented respiratory syncytial virus infection. RESULTS: Of the 28 infants (mean [+/- SD] age, 1.4 +/- 1.7 months) enrolled, 7 had underlying diseases predisposing them to severe infection (mean age, 3.0 +/- 2.6 months), and 21 were previously normal (mean age, 0.8 +/- 0.9 month). Among the 14 infants who received ribavirin, the mean duration of mechanical ventilation was 4.9 days (as compared with 9.9 days among the 14 who received placebo; P = 0.01), and the mean length of supplemental oxygen use was 8.7 days (as compared with 13.5 days; P = 0.01). The mean length of the hospital stay was 13.3 days after treatment with ribavirin and 15.0 with placebo (P = 0.04). When only the 21 previously normal infants were considered, the mean length of the hospital stay was 9.0 days for the ribavirin recipients and 15.3 days for those who received placebo (P = 0.005). CONCLUSIONS: In infants who require mechanical ventilation because of severe respiratory syncytial virus infection, treatment with aerosolized ribavirin decreases the duration of mechanical ventilation, oxygen treatment, and the hospital stay.

Aerosols↗
PubMed1991

Plasma dopamine, norepinephrine, epinephrine and DOPAC levels in preterm infants prior to and immediately after a sleep ventilation hypercarbia test.

The postnatal maturation and the adaptational ability of the sympathoadrenal system has been investigated in preterm neonates (n = 8), and in sick preterm neonates with respiratory disorders (n = 10). Plasma levels of dopamine (DA), norepinephrine (NE), epinephrine (E) and 3-4 dihydroxyphenylacetic acid (DOPAC) were evaluated at rest during the first month of life, and following an inhalation of a 5% carbon dioxide-21% oxygen mixture for 10 min. During the first month of life the sick preterm neonates exhibited similar NE, E, and DOPAC plasma levels but higher DA amounts than healthy infants. Plasma DA levels were inversely correlated with the transcutaneous oxygen tension (r = -0.636) indicating that hypoxemia was able to enhance the release of DA. Immediately following the hypercarbia test, there were no significant changes of plasma catecholamine levels in the sick preterms, but there was a significant increase of E plasma levels (+140%, p less than 0.05) and a moderate elevation of NE and DA amounts in the healthy preterms. It is concluded that preterm neonates who have had respiratory disorders did not exhibit an immaturity of the sympathoadrenal system at rest, but had a defect in the release of E following hypercarbia exposure, which may be secondary to an alteration in chemoreceptor function and/or reduced catecholamine stores.

3,4-Dihydroxyphenylacetic Acid↗
PubMed1991

Incidence of bronchopulmonary dysplasia, growth failure, and pulmonary dysfunction assessed by clinical scoring.

A clinical scoring system was used to determine retrospectively whether the severity of bronchopulmonary dysplasia (BPD) in 67 preterm infants at 21 to 27 days of age would predict the need for home supplemental oxygen or growth retardation (weight less than 5th percentile at 12 months of age). The scoring system was composed of five variables, including fractional inspiratory oxygen, partial pressure of CO2, respiratory rate, chest retractions, and growth rate. The score did not predict the need for home supplemental oxygen or growth retardation (P = .87 and .79, respectively); in contrast, the number of hours of oxygen greater than 80% was significantly correlated with home O2 use (P = .0001) and growth retardation at 1 year of age (P = .013). Since there is no simple predictive score that can be used to determine the functional severity of BPD, each at-risk infant must be clinically evaluated for the degree of pulmonary dysfunction, the need for O2 supplementation, and other supportive pulmonary care prior to discharge.

Birth Weight↗
PubMed1990

Fatal postoperative Legionella pneumonia in a newborn.

This is a case of postoperative Legionella pneumonia in a full-term infant with hypoplastic left heart syndrome. The infant had an uncomplicated prenatal history, normal vaginal delivery, Apgars of 8 at 1 and 5 minutes, but was cyanotic at birth. At 3 days of age she had a stage 1 Norwood surgical procedure to palliate her congenital heart disease. A synthetic patch was placed over the thoracic midline because of difficulty in reapposing the sternum. Peritoneal dialysis was used to manage renal failure. At 20 days of age she had disseminated intravascular coagulopathy and pneumonia associated with sepsis. Four days later she died. Legionella pneumophila serogroup 1 was isolated from a lung culture taken at autopsy.

Adult↗
PubMed1989

Periodic breathing parameter values depend on specific pneumogram scoring criteria.

Periodic breathing (PB) has been related to both normal and pathologic respiratory system control in infants. However, comparison of the results of separate studies has been limited by the variability in procedures used by different investigators to quantify PB. In this study we scored 15 24-hr impedance pneumograms using the criteria of Parmelee et al. (Neuropediatrie 3:294-304, 1972), Christova-Gueorguieva (Biology of the Neonate 44:325-332, 1983), and Curzi-Dascalova, Kelly and Shannon (Pediatrics 63:355-360, 1979) and analyzed the resulting differences in several commonly used PB parameters. Scoring criteria consistently and significantly influenced three PB parameters: the %PB, number of episodes of PB/100 min recording time, and mean duration of PB episode length showed average changes of 74%, 179%, and 36%, respectively, when the methods with the most extreme differences were compared. In contrast, the duration of the longest episode of PB showed no significant change as a function of scoring criteria. Awareness of the particular method of PB scoring is therefore essential in interpreting PB parameter values.

Cardiography, Impedance↗
PubMed1989

Periodic breathing in preterm infants: influence of bronchopulmonary dysplasia and theophylline.

Periodic breathing (PB) has been studied extensively in both normal term infants and term infants presumed to be at high risk for sudden infant death syndrome (SIDS); however, little is known about the incidence and significance of PB in preterm infants. Twenty-four hour impedance pneumograms were obtained from 108 preterm infants prior to their discharge from the nursery and four PB parameters (%PB, No. of episodes of PB/100 min, mean duration of PB episode length, and duration of the longest episode of PB) were quantified in each recording. Control infants who were asymptomatic for apnea had the highest PB parameter values (%PB, 12.0; No. episodes/100 min, 8.6; mean duration, 1.2 min; and longest episode, 7.3 min); infants with bronchopulmonary dysplasia (BPD) showed dramatic decreases in all PB parameters, with a median %PB of 1/16 of the control population. Theophylline use was associated with a significant decrease in PB parameter values only in infants without BPD. Central apneas greater than 15 s did not vary significantly as a function of BPD, theophylline, or postconceptional age. We conclude that the clinical status of preterm infants significantly influences PB parameter values and must be taken into account in the interpretation of pneumograms, for decision-making about home cardiorespiratory monitoring, and in assigning risk for SIDS.

Acoustic Impedance Tests↗
PubMed1989

Periodic breathing cycle duration in preterm infants.

Periodic breathing cycle duration (PCD), the time interval from the beginning of one respiratory pause to the beginning of the next pause within an episode of periodic breathing (PB), was measured by examination of 24-h impedance pneumograms in 51 preterm infants. Calculations of the SD of PCD within a given PB episode (approximately 3 s) and comparison of PCD values between two PB episodes in each infant (r = 0.68) revealed considerable variability in PCD. This variability was not related to the number of cycles in the PB episode or to the amount of PB in the recording. Contrary to the decrease in PCD from 15.0 s at 1 wk to 12.4 s at 12 wk in term infants reported previously, PCD did not vary as a function of postconceptional, gestational, or postnatal age in our preterm population. PCD has limited value as an indicator of chemoreceptor maturation in the preterm infant, and most likely reflects transient adjustments in respiratory system control.

Aging↗
PubMed1989

The effect of dexamethasone on chronic pulmonary oxygen toxicity in infant mice.

The effect of dexamethasone (0.1, 1, and 5 mg/kg/d given subcutaneously from d 14-18) was tested in infant mice continuously exposed from birth to either humidified air or 80% oxygen. Dexamethasone significantly decreased lung wet wt (p less than 0.01), lung water (p less than 0.021), lung dry wt, protein, and DNA (p less than 0.001) in both air- and oxygen-exposed animals. Dexamethasone, however, had no effect on lung compliance measured after animals were killed on d 18. It also had no effect on the increase in the blood-air barrier thickness or decrease in the blood-air exchange surface area seen in the 80% oxygen-exposed mice. Dexamethasone decreased thymus gland wt (p less than 0.001), body wt gain (p less than 0.001), brain wt (p less than 0.001), and lung lymphocytes (p less than 0.05) in both air- and oxygen-exposed animals. The effect of 1 mg/kg and 5 mg/kg of the drug could not be differentiated. During the 4 d of drug administration, one air- and one oxygen-exposed animal died; both received 5 mg/kg/d of dexamethasone; microscopic and culture evidence of infection was not found. If dexamethasone causes similar effects in human infants with bronchopulmonary dysplasia, it should be used with great caution even for short-term clinical management.

Animals↗
PubMed1989

Periodic breathing in preterm infants: incidence and characteristics.

The prevalence and characteristics of periodic breathing in preterm infants were measured by 24-hour impedance pneumograms in 66 preterm infants before discharge from the nursery. Four periodic breathing parameters (percentage of periodic breathing per quiet time, number of episodes of periodic breathing per 100 minutes of quiet time, mean duration of periodic breathing, and longest episode of periodic breathing) were compared to data available from healthy term infants and from term infants who subsequently died of sudden infant death syndrome (SIDS). Periodic breathing was found in all preterm infants studied and mean periodic breathing parameter values (12.0%, 8.6 episodes, 1.2 minutes, and 7.3 minutes, respectively) in our preterm population were substantially higher than values from healthy term infants and SIDS victims. Most periodic breathing parameters decreased significantly in infants studied at 39 to 41 weeks' postconceptional age compared with earlier postconceptional age groups. No relationship was found between central apneas of greater than or equal to 15 seconds' duration and postconceptional age or any periodic breathing parameter. Periodic breathing is a common respiratory pattern in preterm infants that is usually not of pathologic significance. Associations between elevated levels of periodic breathing and respiratory dysfunction or SIDS should be made with caution.

Apnea↗
PubMed1988

A randomized, placebo-controlled trial of effects of dexamethasone on hypothalamic-pituitary-adrenal axis in preterm infants.

As part of a blinded, randomized, placebo-controlled study of dexamethasone therapy in 27 preterm infants with bronchopulmonary dysplasia, we investigated the effect of 7 days of high-dose glucocorticoid therapy on the hypothalamic-pituitary-adrenal axis. Before therapy the median basal cortisol concentration in all infants was 8.2 micrograms/dl (226 nmol/L). After stimulation with 1-24 ACTH, the serum cortisol concentration rose in all infants to a median concentration of 23.5 micrograms/dl (649 nmol/L), resulting in a median rise of 13.4 micrograms/dl (37 nmol/L). Immediately after 7 days of glucocorticoid therapy basal and peak cortisol concentrations were significantly decreased in the dexamethasone group. The rise in serum cortisol following 1-24 ACTH, however, remained equivalent in both groups. Ten days after the end of therapy basal and peak cortisol concentrations in the dexamethasone group had returned to levels equivalent to those seen in the placebo group. Weight gain was markedly diminished while the infants were receiving dexamethasone. Weight gains were, however, equivalent 10 days after the end of treatment. These data indicate that 7 days of dexamethasone therapy has significant but short-term effects on cortisol secretion and possibly on weight gain.

Bronchopulmonary Dysplasia↗
PubMed1988

Dissociation of mean airway pressure and lung volume during high-frequency oscillatory ventilation.

Eight kittens were studied during high-frequency oscillatory ventilation (HFOV) using an airway vibrator. HFOV was performed at 1000 and 1800 cycle/min at three present oscillatory amplitude settings and with lungs normal and injured by saline lavage. Change in lung volume (LV) during HFOV was compared to change in LV obtained during static inflation at matched mean airway pressure (Paw) of 5, 10, 15 and 20 cm H2O. LV during HFOV was significantly higher than during static inflation, and increased as oscillatory amplitude increased. LV was significantly lower after lung injury for matched HFOV settings, and was not affected by rate. Dissociation of Paw and LV during HFOV is observed implying that mean alveolar pressure (Palv) exceeds Paw during HFOV in this experimental model. The safe clinical application of HFOV may involve measurement of Palv or LV.

Airway Resistance↗
PubMed1988

Interference of fetal hemoglobin with the spectrophotometric measurement of carboxyhemoglobin.

We measured the concentration of carboxyhemoglobin (HbCO) in blood samples from 32 neonates by spectrophotometry (IL282 CO-Oximeter) and gas chromatography, finding a strong positive correlation (r = 0.89) between the concentration of fetal hemoglobin (Hb F) and HbCO as measured by spectrophotometry, but not by gas chromatography. Thus, Hb F interferes with the determination of HbCO by spectrophotometric techniques by falsely increasing apparent HbCO in direct proportion to Hb F. We conclude that, when Hb F is known or suspected to be present, blood HbCO cannot be reliably determined by methods based on spectrophotometry.

Carboxyhemoglobin↗
PubMed1987

Placental pathology is not predictive for sudden infant death syndrome (SIDS).

A previous report has suggested an increased incidence of chorioamnionitis in the placentae of sudden infant death syndrome (SIDS) victims. To further evaluate placental pathology in SIDS, 27 cases were identified from coroner's records and matched to two control groups. Both control groups were matched for birthweight, gestational age, and season, with the second also matched for maternal race, infant sex, blood type B, and maternal parity. No significant increase in chorioamnionitis or other placental abnormalities were found in SIDS victims when controlling for prematurity, which is a factor related to chorioamnionitis. An increased incidence of vaginal bleeding (P less than 0.04) and possibly substance abuse or anemia at delivery was found in SIDS mothers. There were more premature and black infants found in the SIDS group compared with the general birth population, and also lower five-minute Apgar scores (P less than 0.02) compared to matched controls. Analysis of the second control group match, including infant Apgar scores, maternal hematocrit, maternal age, and complications of pregnancy and delivery, did not influence any of our conclusions. The data suggests that matching for prematurity may be important in identifying the strength of additional risk factors for SIDS, since the risk factors for SIDS and premature delivery are similar.

Adult↗
PubMed1985

Use of sodium nitroprusside in neonates: efficacy and safety.

Sodium nitroprusside was administered to 58 neonates, including 11 with severe respiratory distress syndrome, 15 with persistent pulmonary hypertension of the newborn, 28 with clinical shock, three with systemic hypertension, and two with pulmonary hypoplasia, all refractory to conventional intensive therapy. Nitroprusside was infused at 0.2 to 6.0 micrograms/kg/min for periods of 10 minutes to 126 hours. Infants with severe respiratory distress syndrome had increased PaO2 and decreased PaCO2 or peak inspiratory pressure, and nearly all (82%) survived. Infants with persistent pulmonary hypertension of the newborn had variable responses; improvement did not correlate with survival, but survival (47%) was identical to that in an earlier series of infants given tolazoline. Infants in shock had improved perfusion, urine output, and serum bicarbonate levels, and these responses were significantly related to survival. Hypertension was controlled in all three hypertensive infants. Adverse effects were very uncommon. Toxic effects were not observed. Sodium nitroprusside is effective and can be used safely in circulatory disorders in the neonate.

Bicarbonates↗