T F Yeh

Metabolic rate and energy balance in infants with bronchopulmonary dysplasia

To determine energy use and growth of infants with bronchopulmonary dysplasia (BPD), we studied metabolic rate and energy balance in five infants with stage III-IV BPD (birth weight 1309 +/- 530 gm, gestational age 32 +/- 3 weeks, postnatal age 59.8 +/- 14.2 days) and in five control infants (birth weight 1540 +/- 213 gm, gestational age 33 +/- 2 weeks, postnatal age 42.0 +/- 4.2 days). Infants with BPD had significantly lower energy intake but higher energy expenditure than did control infants. Weight gain and energy cost of growth were significantly less in BPD infants than in control infants, as were urine output and output/intake ratio. We conclude that infants with BPD (1) absorbed caloric intake as well as did normal control infants, (2) had low energy intake and high energy expenditure, resulting in poor weight gain, and (3) had low energy cost of growth, suggesting an alteration in composition of tissue gain, with relatively high water content.

Early furosemide therapy in premature infants (≤2000 gm) with respiratory distress syndrome: A randomized controlled trial

Pulmonary edema has been demonstrated in the early stages of respiratory distress syndrome in premature infants. To evaluate whether early furosemide therapy (0 to 8 hours after birth) would affect the electrolyte balance, pulmonary status, and outcome, 57 infants (≤2000 gm) with respiratory distress syndrome who required mechanical ventilation shortly after birth were randomized into two groups: 29 given furosemide (1 mg/kg/day intravenously for three doses) and 27 control. The clinical, biochemical, and laboratory characteristics of the groups were comparable before entry into the study. Administration of furosemide significantly enhanced the urinary excretion of Na and Cl at 0 to 24, 24 to 48 and 48 to 72 hours and of Ca at 24 to 48 and 48 to 72 hours after drug administration. There was no significant difference between the groups in urinary excretion of K and in serum Na, Cl, K, and Ca values. A spontaneous increase in urine output occurred in the control groupat 48 to 72 hours after the initiation of the study (mean -SD 7.0±3.5 hours postnatal age), along with a decrease in mean airway pressure for mechanical ventilation. The use of furosemide (7.3±3.5 hours postnatal age) enhanced urine output at 24 to 48 and 48 to 72 hours after medication, resulting in further decrease in mean airway pressure and facilitating extubation. There was, however, no significant difference between the groups with respect to incidence of patent ductus arteriosus, morbidity from bronchopulmonary dysplasia, and mortality.

Lung volume, dynamic lung compliance, and blood gases during the first 3 days of postnatal life in infants with meconium aspiration syndrome.

Serial measurements of pulmonary function and arterial blood gases during the first 3 postnatal days of life were obtained in 12 infants with meconium aspiration syndrome (MAS). Nine normal neonates with similar weight and gestational age were studied as controls. Infants with MAS had significantly lower pH on day 1, and had greater P(A-a)O2 throughout the study period than that of normal controls. The Pco2 was comparable between the groups. Both dynamic lung compliance (Cdyn) and specific lung compliance (C/VL) were lower in infants with MAS as compared with those of normal infants. The functional residual capacity (FRC) for normal infants on days 1, 2, and 3 were 2.0 ± 0.3, 2.1 ± 0.3, and 2.2 ± 0.3 ml/cm, respectively, and for infants with MAS were 1.8 ± 0.4, 2.3 ± 1.1, and 2.2 ± 0.6 ml/cm, respectively. Radiographic hyperinflation of the lungs was seen in 6 infants with MAS on day 1; 3 were associated with high FRC (>2 SD) of normal) and 2 with low FRC, indicating air trapping. The early use of PEEP should be cautious if hyperinflation or air trapping is present.

Clinical evaluation of premature infants with patent ductus arteriosus: A scoring system with echocardiogram, acid-base, and blood gas correlations

To provide a clinical assessment of cardiovascular dysfunction (CVD) in premature infants with patent ductus arteriosus (PDA), a scoring system (CVD score) was devised and correlated with blood gases, acid-base balance, and echocardiogram. The score consisted of evaluation of heart rate, quality of peripheral arterial pulsation, degree of precordial pulsation, duration of murmur and cardiothoracic ratio on chest roentgenogram.There were 116 observations made on 55 premature infants who had PDA and required medical or surgical treatment. Significant positive correlations were seen for CVD score with left atrial (LA)/aortic (Ao) ratio (p < 0.001), left ventricular end diastolic dimension (DD) (p < 0.001), blood pH (p < 0.01), and blood Pco2 (p < 0.01). The scoring system may be used as a clinical guide when echocardiogram or angiogram is not available.

Mercury Poisoning from Mercurochrome Therapy of an Infected Omphalocele

A neonate with an infected omphalocele was treated locally with merbromin (mercurochrome) for five days. Extensive skin peeling with bullous lesions, edema, and fever developed three days after mercurochrome therapy. The infant died on the ninth day. Autopsy revealed evidence of heavy metal poisoning of the kidney, excessive mercury levels in the blood, and in tissues of the brain, kidney, and liver.

Simple daily technique to calculate total and interim changes of daily O2 consumption and CO2 production in premature infants.

A simple method to calculate oxygen consumption (VO2) and CO2 production (VCO2) over a 24-h period is described. VO2 and VCO2 were measured using flow-through technique and the total VO2 and VCO2 over a given period of time were determined from the area under the O2 and CO2 concentration-time curve of the mixed expired gas. The system was tested in vitro by burning 100% ethyl alcohol. The average error between measured and theoretical values for VO2 was 4.9% and for VCO2 was 4.7%. With a flow rate greater than 5340 ml/min through the system, the correlation coefficient between theoretical VO2 or VCO2 and measured VO2 or VCO2 was 0.99. The method was tested in vivo in 5 premature infants who were nursed under neutral thermal environment and received routine medical care. The results indicate that this simple method can be used to study the total and interim changes of daily VO2 and VCO2 in infants during their ongoing nursery care.

MERCURY POISONING FROM MERCUROCHROME THERAPY OF INFECTED OMPHALOCELE

A neonate with an infected omphalocele was treated locally with merbromin (mercurochrome) for five days. Extensive skin peeling with bullous lesions, edema, and fever developed three days after mercurochrome therapy. The infant died on the ninth day. Autopsy revealed evidence of heavy metal poisoning of the kidney, excessive mercury levels in the blood, and in tissues of the brain, kidney, and liver.

Renal response to frusemide in preterm infants with respiratory distress syndrome during the first three postnatal days

The renal effects of frusemide treatment in infants with respiratory distress syndrome shortly after birth and during the first three postnatal days were evaluated. Eighty five infants were randomly assigned to two groups. Forty two received three doses of intravenous frusemide (1 mg/kg) starting at age, mean (SD) 7.5 (4.1) hours and given at approximately 24 hour intervals. Forty three control infants were treated similarly but were not given frusemide. The groups were comparable in birthweight, gestational age, and Apgar score and in pulmonary status, blood gases, serum electrolytes, and postnatal age. Infants who received frusemide had significantly higher fractional excretion of sodium and chloride at 12 to 24, 24 to 48, and 48 to 72 hours, and higher calcium excretion at 24 to 48 and 48 to 72 hours after entry into the study than control infants. The study group had a significantly higher urine output and greater weight loss than the control group at 48 to 72 hours after entry into the study. There was no significant difference between groups in serum sodium, potassium, and calcium and in fractional excretion of potassium and the glomerular filtration rate. Infants with an Apgar score of more than 3 had higher urine output and had a better diuretic response to frusemide than those with a lower score. The results suggest that perinatal hypoxia may play an important role in renal function and in diuretic response to frusemide shortly after birth and early in the postnatal life of infants with respiratory distress syndrome.

1493 THE EFFICACY OF CHEST PHYSIOTHERAPY (CPT) ON THE FIRST POSTNATAL DAY IN INFANTS WITH RDS

To study the efficacy of CPT (vibration, percussion and suction) on the first postnatal day, 20 infants (mean±S.D. B.W. 1.2±0.4 kg, G.A. 30±2 wks, Postn. A. 4.9±3.5 hr) with RDS and on asst. vent. shortly after birth were randomly assigned to two grs. Gr. I (10) with CPT, Gr. II (10) ET suction only. CPT or suction were performed every 2 hrs. Vibration and percussion were performed for 15 seconds in 4 different postures, followed by ET suction. The parameters evaluated included: blood gases, pH, mean airway pressure (MAP), ET secretion, incidence of air leaks, IVH, PDA.Infants in Gr I had sign. (p<0.05) lower MAP than Gr II at 16 hrs. The blood gases and pH were comparable. There was no sign. difference between the groups in ET secretions per suction at 0-8, 8-16 and 16-24 hrs (Gr I 0.1±0.1, 0.1±0.1, 0.1±0.1 gm vs Gr II 0.1±0.2, 0.1±0.1, 0.1+±0.1 gm respectively) and in incidence of air leaks (2/10 vs 3/10), IVH (7/10 vs 3/10), PDA (4/10 vs 5/10) and duration of O2 and IMV therapy. However, Gr I infants had sign. (p<0.05) higher incidence (5/10) of severe IVH (≥Grade II) than Gr II (0/10). We conclude that vibration and percussion are not beneficial and may be detrimental during the first postnatal day.

1563 INDOMETHACIN (I) THERAPY IN PREMATURE INFANTS WITH PDA — DETERMINATION OF THERAPEUTIC PLASMA LEVELS

To determine the therapeutic plasma levels of I, 38 infants (mean±S.D., B.W. 1.2±0.4 kg, G.A. 32±2 wks, Postn. A. 10.2±2.2 days) with sign. PDA were given 0.1 mg/kg or 0.3 mg/kg I as 1st dose followed by 0.2 and 0.3 mg/kg or 0.3 mg/kg at 24 hrs interval for 3 doses unless PDA closed. Plasma samples for I assay and Echo LA/AO ratios were obtained at 0, ½, 1, 2, 4, 6, 12, 24, 36, 48, 60 and 72 hrs after 1st dose. Closure of ductus was assessed at 24 hrs after dosing. Side effects evaluated included 1) U/0 2) hyponatremia (≤130 mEq/L) 3) hyperkalemia (≥6.5 mEq/L) 4) NEC.The mean t½ was 21.6 hrs, AVD 0.3 L/kg, clearance 9.2 ml/kg/hr. Sign. correlation (P<0.05) was seen between t½, clearance and postn. age, but not with G.A. or B.W. Ductus response and renal side effects correlated (P<0.05) with plasma I at 12, 24 hrs, and 6, 12 hrs post-dosing respectively but none correlated with peak I levels. Ductus response to I was dose-dependent and correlated with AUC of plasma I, but not renal side effects. The 12 hrs post-dosing plasma levels have the best correlation with ductus response and side effects; to achieve 50% success or more, a level of 0.5 μg/ml is needed. (Fig.)