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Biomedical subjects

E Bancalari

Publications and source records attributed to E Bancalari.

At least 109 records · Page 6Linked to original sources
PubMed1987

Effect of cyclooxygenase and lipoxygenase products on pulmonary function in group B streptococcal sepsis.

The effects of the cyclooxygenase inhibitor, indomethacin, and the leukotriene receptor antagonist, FPL 57231, on changes in dynamic lung compliance and pulmonary resistance associated with a 1-h infusion of live group B streptococci were evaluated in mechanically ventilated piglets. To define mediators of early changes in lung function, animals were given an infusion of either FPL 57231 or indomethacin beginning 15 min after the infusion of group B streptococci was begun. These groups were compared to an untreated group who received only group B streptococci. Within 15 min of starting the bacterial infusion, all groups showed significant increases in pulmonary artery pressure, pulmonary artery wedge pressure, total pulmonary resistance, transpulmonary pressure, and thromboxane B2, and decreases in tidal volume, dynamic lung compliance, and PaO2. After treatment with indomethacin there were significant decreases in pulmonary artery pressure (mean +/- SEM; 48 +/- 1 to 22 +/- 3 mm Hg, p less than 0.001), pulmonary artery wedge pressure (7.5 +/- 1.3 to 2.2 +/- 0.4 mm Hg, p less than 0.001) and thromboxane B2 (6.51 +/- 1.56 to 1.01 +/- 0.27 ng/ml, p less than 0.01) and an increase in dynamic lung compliance (1.10 +/- 0.10 to 1.28 +/- 0.14 ml/cm H2O/kg, p less than 0.01) over the study period. Total pulmonary resistance decreased significantly (18.7 +/- 1.8 to 15.7 +/- 1.5 cm H2O/liter/s, p less than 0.02) only at 60 min.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1987

High-frequency ventilation in the neonate.

HFV is a mode of therapy that allows gas exchange with pressure fluctuations much lower than that required for conventional ventilation, and may consequently decrease the incidence of barotrauma and chronic lung disease. At present the National Institute of Health is sponsoring the first large controlled trial to test the efficacy of HFV using an oscillator in premature infants with respiratory failure. Results of this trial will help to clarify some of the indications for HFV and its usefulness in a large number of infants with respiratory failure secondary to RDS.

Animals↗
PubMed1987

Influence of transcutaneous oxygen monitoring on the incidence of retinopathy of prematurity.

This study was performed to determine whether the use of continuous transcutaneous oxygen tension (tcPO2) monitoring could reduce the incidence of retinopathy of prematurity in preterm infants receiving oxygen therapy. A total of 296 infants with birth weights less than or equal to 1,300 g were randomly assigned to a continuous monitoring or a standard care group. Infants in the continuous monitoring group had tcPO2 monitored continuously as long as they required supplemental oxygen, and infants in the standard care group had tcPO2 monitored only during the more acute state of their illness. Management of both groups was otherwise identical. Of 148 infants in the continuous monitoring group, 101 survived; of the 148 patients in the standard care group, 113 survived. Mean birth weights and gestational ages were similar for both groups. Duration of mechanical ventilation and oxygen therapy was also similar. The overall incidence of retinopathy of prematurity was 51% in the continuous monitoring group and 59% in the standard care group. As birth weight for infants greater than or equal to 1,000 g increased, a higher risk of retinopathy of prematurity developing was noted in the standard care group. Cicatricial retinopathy of prematurity developed in four infants in the continuous monitoring group and five in the standard care group. These results suggest that continuous tcPO2 monitoring may reduce the incidence of retinopathy of prematurity in infants with birth weights greater than 1,000 g but not in the smaller infants in whom this complication occurs more frequently and is more severe.

Birth Weight↗
PubMed1987

Blood transfusion effect on the respiratory pattern of preterm infants.

Anemia may increase the risk of tissue hypoxia in preterm infants. This could lead to respiratory center depression and an increased risk for apnea. Heart rate and breathing pattern were recorded in 30 preterm infants (gestational age 30.0 +/- 2.3 weeks, postnatal age 46.6 +/- 20.8 days, and weight 1,438 +/- 266 g) before and after a transfusion of 10 mL/kg of packed RBCs. All infants were stable clinically, breathing room air, and free of prolonged apneic episodes. After transfusion, hematocrit levels increased from 27.0% +/- 2.5% to 35.8% +/- 4.7%. Heart rate decreased from 157.2 +/- 13.6 beats per minute to 148.4 +/- 13.9 beats per minute. There was no change in respiratory rate or BP. The duration of periodic breathing decreased significantly, as did the duration of the longest periodic breathing episode (P less than .01). The number of respiratory pauses lasting 5 to 10 seconds and the number of pauses lasting 11 to 20 seconds also decreased significantly (P less than .05). The total duration of respiratory pauses, excluding pauses during periodic breathing, were significantly lower after transfusion (P less than .05), as was the number of episodes of bradycardia. These results indicate that preterm infants have a more irregular breathing pattern while anemic than after correction of the anemia. The irregular breathing pattern is probably caused by mild hypoxic respiratory center depression.

Anemia↗
PubMed1987

Retinopathy of prematurity. Diagnosis, severity, and natural history.

This article presents data gathered in a prospective clinical trial of constant monitoring of oxygen therapy on the diagnosis, severity (as coded by a severity index [SI]) and natural history of retinopathy of prematurity (ROP) in 214 surviving infants with birthweights less than or equal to 1300 g. ROP developed in 119 (55.6%) infants and, of these, cicatricial ROP developed in nine (7.6%). The disease was diagnosed at 8-9 weeks on the average in infants with birthweights less than 900 g and 4-5 weeks in infants 900 to 1300 g. Those infants in whom the disease regressed, ROP lasted approximately 15 weeks. The severity of the disease, as defined by the SI, was strongly correlated with the birthweight of the infant and weakly correlated with the total duration of oxygen therapy.

Cicatrix↗
PubMed1986

Use of barbiturate therapy in severe perinatal asphyxia: a randomized controlled trial.

The possible cerebral sparing effect of thiopental was evaluated in 32 severely asphyxiated neonates randomly assigned to either a thiopental treatment or control group. All infants had neurologic manifestations of asphyxia and required assisted ventilation. Thiopental was begun at a mean age of 2.3 hours and was given as a constant infusion that delivered 30 mg/kg over 2 hours. Treatment was continued at a lower dose for 24 hours. Seizure activity occurred in 76% of infants given thiopental and 73% of control infants at a mean age of 1.5 and 2.5 hours, respectively. Although initial arterial blood pressure was similar in both groups, hypotension occurred in 88% of treated and 60% of control infants. The amount of blood pressure support required was significantly greater (P less than 0.005) in the thiopental treatment group. Three infants died in the control group, and five in the treatment group. Developmental assessment was performed at a minimum of 12 months of age in 22 infants. There were no significant differences in neurologic, cognitive, or motor outcome between groups. Deteriorating performance over time was a consistent trend in both groups. These findings indicate that treatment of severe perinatal asphyxia with thiopental does not appear to have a cerebral sparing effect and may be associated with significant arterial hypotension.

Apgar Score↗
PubMed1986

Bronchopulmonary dysplasia.

Bronchopulmonary dysplasia has become the most common pulmonary sequelae in neonates receiving mechanical ventilation. The pathogenesis of BPD is multifactorial, but prematurity, positive pressure ventilation, oxygen toxicity and pulmonary edema are some of the most important factors in its development. By minimizing these factors, it is possible to reduce the incidence and severity of BPD.

Airway Resistance↗
PubMed1986

Renal bicarbonate handling in low birth weight infants during metabolic acidosis.

We studied the fractional excretion of bicarbonate (FE HCO-3) in 10 low birth weight infants aged 1-6 days during metabolic acidosis (base excess greater than or equal to -5 mEq/l) and during subsequent sodium HCO-3 infusion. The mean birth weight was 1,095 g; the mean gestational age was 29 weeks. The ability to decrease urine pH to less than 5.5 and FE HCO-3 to less than 1% during metabolic acidosis was not limited by low gestational age or birth weight. After HCO-3 therapy, all infants corrected their negative base excess, and plasma HCO-3 increased significantly. All infants with blood pH less than or equal to 7.22 or PaCO2 greater than or equal to 50 mm Hg had minimal or absent FE HCO-3. Infants with elevated PaCO2 and mild or absent acidosis also had complete HCO-3 tubular reabsorption. These results suggest that the HCO-3 tubular reabsorption is adequate during metabolic and/or respiratory acidosis in low birth weight infants.

Acidosis↗
PubMed1986

Functional residual capacity in normal neonates and children up to 5 years of age determined by a N2 washout method.

Functional residual capacity (FRC) was determined in 50 infants by a simplified N2 washout method. Fourteen infants were preterm, four full-term newborns and the rest were 1 month to 5 yr of age. Weight ranged from 1.19 to 25.8 kg. The method gave well reproducible values with a mean coefficient of variation of 3.9%. The FRC values are equally well correlated to weight and length (r = 0.98). The correlation with weight is linear, intercepting the x axis (FRC = 0) at a weight of 480 g, the one with length is best described by a power curve. The course of the regression lines reflects the observation that FRC per kg weight or per cm length is lower in neonates than in larger infants. The FRC measurements are in the same range as values obtained by other investigators using the N2 washout or He-dilution techniques. The values are significantly smaller than thoracic gas volume measurements obtained by plethysmography. This difference may be due to air trapping or to possible methodological problems with the plethysmographic technique. The data demonstrate that FRC can be measured easily and accurately in preterm and older infants using a N2 washout technique.

Child, Preschool↗
PubMed1986

Effects of a leukotriene antagonist on the early hemodynamic manifestations of group B streptococcal sepsis in piglets.

In order to evaluate the influence of leukotrienes on group B streptococcal (GBS) sepsis we studied the effect of a leukotriene antagonist, FPL 57231, on the early hemodynamic changes occurring secondary to an infusion of live GBS. Paralyzed, mechanically ventilated piglets received a continuous intravenous infusion of bacteria (5 X 10(8) org/kg/min) while systemic arterial pressure and pulmonary artery pressure were measured continuously. Cardiac output was measured by thermodilution; and plasma samples for determination of thromboxane B2 and 6-keto-PGF1 alpha were taken at preset intervals. In addition to GBS, treatment animals received a continuous infusion of FPL 57231 starting 15 min after the bacterial infusion was begun. Study animals as a whole responded to bacteria within 15 min with a marked elevation in pulmonary artery pressure from 13.6 +/- 4 to 44.6 +/- 6 mm Hg (p less than 0.001), and a decline in PaO2 (79 +/- 9 to 44 +/- 5 mm Hg) (p less than 0.001) and a cardiac output (0.27 +/- 0.07 to 0.15 +/- 0.06 liter/min/kg) (p less than 0.0001). In animals treated with FPL 57231 these changes were reversed or significantly attenuated by 60 min. In the control group pH deteriorated significantly to 7.17 +/- 0.1 compared to baseline values (p less than 0.01) by 60 min, while treatment group animals maintained a pH of 7.3 +/- 0.23. Thromboxane B2 and 6-keto PGF1 alpha were similar in both groups and did not change during the study period. In addition, survival was significantly longer in treatment (191 +/- 44 min) compared to control animals (100 +/- 32 min) (p less than 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)

6-Ketoprostaglandin F1 alpha↗
PubMed1985

Conventional vs high-frequency jet ventilation in a piglet model of meconium aspiration: comparison of pulmonary and hemodynamic effects.

The pulmonary and cardiovascular effects of high-frequency jet (HFJV) and conventional (CV) ventilation were evaluated in a piglet model of meconium aspiration. A mixture of 20% human meconium and 0.9% saline solution was instilled deep into the trachea of 10 piglets, after which either HFJV or CV was administered for 4 hours. Arterial blood gases, cardiac output, mean pulmonary and systemic arterial pressures, pulmonary and systemic vascular resistances, and pulmonary mechanics were compared between groups. During the 4 hours of ventilation, PaO2 and PaCO2 were not statistically different between groups. The peak inspiratory pressure necessary to maintain PaCO2 in the preset range was approximately half as much in the HFJV group as in the CV group (P less than 0.002). Mean airway pressure was lower in the HFJV group only during the second hour (P less than 0.03). Cardiac output, mean aortic and pulmonary artery pressures, systemic and pulmonary vascular resistance, dynamic lung compliance, and pulmonary resistance were not statistically different between groups. Our results suggest that HFJV may be more effective than CV in the early stages of meconium aspiration syndrome because HFJV allows more efficient ventilation and adequate oxygenation at lower peak inspiratory pressures.

Animals↗
PubMed1985

A simple method for measuring functional residual capacity by N2 washout in small animals and newborn infants.

An open circuit N2 washout technique is described for the determination of functional residual capacity in infants. Either 100% O2 or any oxygen/helium mixture can be used as the washing gas. The subject breathes the washing gas through a T-tube and the washed out nitrogen is mixed with this gas in a mixing chamber, placed into the exhalation part of the circuit. The N2 concentration of the mixed gas is analyzed continuously, and the concentration signal is electronically integrated over time. Calibration of the system is accomplished by injecting known amounts of nitrogen or room air into the circuit. The gas flow through the system must remain constant and is adjusted to approximate peak inspiratory flow of the infant. In vitro testing of the system showed that the technique gives reproducible values (coefficient of variance less than 1.0%) and that the integrated signal output has a close linear correlation with the amount of N2 washed out (r = 0.99). In vivo measurements in 10 cats confirmed the accuracy and reproducibility of the method when compared with N2 collection. The technical advantages of the system are simplicity of components, absence of valves, easy calibration, low dead space, and no need to collect or measure expired gases. For the infant this means no added resistance during washout and no risk of hypoxia, hyperoxia, or hypercapnea. In the presence of pulmonary disease and poor gas mixing the washout period can be prolonged as needed. There is no lower limit of weight or size for functional residual capacity measurements in small infants or animals.

Animals↗
PubMed1985

Influence of an antagonist of slow-reacting substance of anaphylaxis on the cardiovascular manifestations of hypoxia in piglets.

Leukotrienes have been implicated in the pathogenesis of hypoxic pulmonary hypertension in adult animals and in persistent pulmonary hypertension with accompanying hypoxemia in the neonate. In order to elucidate the role of leukotrienes in hypoxic pulmonary hypertension in a young animal model, the effects of a leukotriene antagonist, FPL 57231, were evaluated in anesthetized piglets. Cardiac output and vascular pressures were measured and pulmonary and systemic vascular resistances calculated prior to and during hypoxia. These measurements were compared during continued hypoxia between a control and treatment group which received FPL 57231. FPL 57231 infusion resulted in significant decreases in mean pulmonary artery pressure (p less than 0.04), pulmonary vascular resistance (p less than 0.01) and the ratio of pulmonary/systemic vascular resistance (p less than 0.01). Systemic vascular resistance fell approximately 25% from hypoxic baseline (p less than 0.01) while PVR decreased 54%. There were no differences between groups in mean systemic arterial pressure, cardiac output, pH, or PaCO2. In addition, pretreatment with FPL 57231 attenuated the hemodynamic response to hypoxia. These data suggest that leukotrienes may, in part, mediate hypoxic pulmonary vasoconstriction in piglets.

Animals↗
PubMed1985

Nutritional balance studies: evaluation of a premature infant formula.

A 24 kcal/oz (81 kcal/100 ml) premature infant formula (Enfamil Premature Formula) with moderately high mineral content (117 mg Ca/100 ml and 58 mg P/100 ml) and a protein content of 3 g/100 kcal was evaluated in sixteen 3-day balance studies at 10 and 21 days of age in nine premature infants with birth weights from 1,200 to 1,400 g. Growth rates were similar to in utero rates, and the formula was well accepted and tolerated. Calcium retention (62.5%) was similar to in utero accretion, and phosphorus retention was only slightly lower. Nitrogen retention was high without the development of metabolic acidosis or abnormal serum urea nitrogen levels.

Calcium↗
PubMed1984

Acute cardiopulmonary effects of pancuronium bromide in mechanically ventilated newborn infants.

The short-term effects of muscle relaxation with pancuronium bromide on arterial blood gas values, heart rate, and arterial blood pressure were studied in 49 neonates receiving mechanical ventilation. After pancuronium administration, mean PaO2 increased from 61.9 +/- 30.0 to 80.9 +/- 52.8 mm Hg (P = 0.006), mean PaCO2 decreased from 40.1 +/- 13.0 to 37.5 +/- 13.3 mm Hg (P = 0.03), and mean heart rate rose from 146.2 +/- 24.9 to 161.0 +/- 20.5 beats/min (P less than 0.001). Arterial blood pressure did not change significantly. When results were analyzed by diagnosis (meconium aspiration syndrome, hyaline membrane disease, pneumonia), only infants with meconium aspiration syndrome had a significant improvement in oxygenation (P = 0.008). Six of 18 patients with hyaline membrane disease responded to muscle relaxation, with a decrease in PaO2 of 10 mm Hg or more. No significant correlation was found between change in PaO2 and birth weight, gestational age, postnatal age, or change in heart rate. A weak correlation (r = -0.37, P less than 0.006) was observed between change in PaO2 and change in PaCO2. Although the reasons for the divergence in response in different groups of patients are not entirely clear, the risk of deterioration with pancuronium therapy should be kept in mind, particularly if treatment in an infant with hyaline membrane disease is being considered.

Blood Gas Analysis↗
PubMed1984

Gastric motility in premature infants fed two different formulas.

The effect of two different formulas on gastric contractions was investigated in 10 preterm infants, of mean birth weight 1,149 g and mean gestational age 30.5 weeks, who were being advanced from a 20 calorie per ounce formula (Enfamil) to a 24 calorie per ounce formula (Similac Special Care 24). The neonates were fed by gravity with a feeding tube on a 2-h schedule. The orogastric tube was connected between feedings to a pressure transducer and recorder system upon which pressure waves reflecting gastric contractions were recorded. In the 1st h after feeding there were significantly fewer gastric contractions with 24 calorie than 20 calorie formula. The mean intensity of the gastric contractions per minute of contraction time was significantly less in the 1st h after feeding with the 24 calorie compared with the 20 calorie formula. In the 2nd h after feeding these values were similar. Gastric contractions are decreased with 24 calorie formula compared with 20 calorie formula during the 1st h after feeding. This difference in contractions may influence tolerance to different formulas.

Energy Intake↗