Lawrence D. Lilien

Plasma glucose values in normal neonates: A new look

Current standards for glucose concentration in neonates have been determined in whole blood and translated into plasma values on the basis that plasma glucose values are 12% to 15% higher than those in whole blood. 1 In addition, the standards 2 are based on birth weight because the concept of gestational age was not fully appreciated until the mid-1960s. Moreover, changes in maternal and fetal monitoring techniques, administration of glucose-containing solutions during labor and delivery, and early feeding of neonates may significantly alter blood glucose concentrations during the first week of postnatal life. This study was undertaken with the hypotheses that glucose values in normal neonates may be different from those previously defined and that neonatal hypoglycemia may need to be redefined. METHODS

Penicillin in Infants Weighing Two Kilograms or Less with Early-Onset Group B Streptococcal Disease

We studied the effect of penicillin on early-onset Group B streptococcal disease over a 52-month period in neonates who were at high risk of infection. Shortly after birth, 1187 neonates weighing 2000 g or less had blood samples taken for cultures and were randomized into an early-treatment group (given intramuscular penicillin G within 60 minutes of birth) or a control group. The incidence of early-onset disease was 20 per 1000 live births (24 of 1187); the number of infants in the early-treatment group who had disease (10 of 589) was similar to that in the control group (14 of 598). The fatality rates were similar in both groups (6 of 10 vs. 8 of 14). Cultures from blood obtained with one hour of birth were positive in 21 of the 24 infants with disease; 22 of the 24 were symptomatic within four hours of birth. Thus, infection was well established before the first hour of postnatal life. At autopsy, gram-positive cocci were seen in lung sections of four infants in whom cultures of blood obtained after treatment had been sterile; this indicates that giving routine antibiotic therapy before culture samples are obtained can obscure bacteriologic diagnosis. We conclude that penicillin given at birth to neonates weighing 2000 g or less does not prevent early-onset streptococcal disease or reduce excess mortality associated with disease.

Furosemide prevents the renal side effects of indomethacin therapy in premature infants with patent ductus arteriosus

To determine if furosemide would prevent the renal side effects of indomethacin therapy in premature infants with patent ductus arteriosus, 19 premature infants were randomized into two groups: nine received indomethacin alone, and ten received indomethacin followed immediately by furosemide. There was no significant difference between the groups in birth weight, gestational age, postnatal age, and in cardiopulmonary or renal status at the time of study. Infants who received indomethacin and furosemide had significantly higher urine output (P less than 0.05), higher FENa and FECl (P less than 0.01), and higher glomerular filtration rate (P less than 0.05) than those of infants who received indomethacin alone. Seven infants in each group responded to indomethacin therapy with disappearance of PDA murmur and improvement of cardiovascular status. The results of this study suggest that furosemide may prevent the renal side effects of indomethacin therapy and yet not affect the efficacy of indomethacin in the closure of a PDA.

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.

Oxygen consumption and insensible water loss in premature infants in single- versus double-walled incubators

Fifteen studies were performed in ten premature infants whose birth weight (mean +/- SD) was 1,444 +/- 250 gm, gestational age 32.7 +/- 1.0 weeks, and postnatal age 10.7 +/- 3.3 days. Each study consisted of three hours simultaneous measurement of insensible water loss and oxygen consumption under two conditions for the same infant: (1) inside a single-walled incubator and (2) inside a double-walled incubator. The double-walled incubator provided significantly (P < 0.001) higher operative temperature and incubator wall temperature than did the single-walled incubator. Infants inside the double-walled incubator had significantly lower (P < 0.01) IWL (30% reduction) and lower (P < 0.05) VO2 (17% reduction) than inside the single-walled incubator--a net caloric saving of 11.8 kcal/kg/day. This saving of energy expenditure may be important in affecting the growth and outcome of the low-birth-weight infants.

Increased O2 Consumption and Energy Loss in Premature Infants following Medical Care Procedures

Oxygen consumption (VO2) and CO2 production (VCO2) were measured continuously for 24 h in 10 premature infants during their ongoing nursing care. Using a flow-through technique, 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. Following chest physiotherapy, heel stick and i.v. needle insertion, there was a significant (p less than 0.01) increase in VO2 and VCO2. When measured for 24 h, the total daily increase of VO2 attributed to these procedures ranged from 2.1 to 11.7% of total daily VO2, equivalent to an estimated energy loss of 0.6-4.1 kcal/kg/day.

Treatment of neonatal hypoglycemia with continuous intravenous glucose infusion

The treatment of neonatal hypoglycemia by constant infusion of glucose at the rate of 8 mg/kg/minute was studied in 22 hypoglycemic neonates. In 18 neonates glucose levels rose above the hypoglycemic range within ten minutes of infusion and in three, within 30 to 50 minutes of infusion. The remaining neonate had hyperinsulinemia and responded only to diazoxide. Constant glucose infusion was found to be useful therapeutically for neonatal hypoglycemia.

Plasma amino acid patterns in very low birth weight infants during parenteral nutrition.

Plasma amino acids were measured in eight very low birth weight infants (≤ 1000 gm) before and after infusion of parenteral alimentations with Freamine III. Significant elevation in serum threonine, valine, isoleucine, methionine, serine, proline, glycine and omithine was noted after twenty four hours of infusion. On the other hand, significant decreases in taurine and tyrosine levels were noted. Our study suggests that current solution is not optimal for premature neonates and the amount of protein administered during the first week in infants weighing ≤ 1000 gm should be decreased from the recommended 2.5–3.0 gm/kg/day.

Maternal Mental Health and Parenting Stress After the Birth of a Very Low Birthweight Infant |[dagger]| 1337

There is little information detailing how families adapt to the experience of VLBW birth and subsequent caregiving demands. Mothers of high risk (HR) VLBW infants with BPD (n = 122), low risk (LR) VLBW infants without BPD (n = 84), and term (T) infants were folowed longitudinally from birth at 8, 12, 24, and 36 months (corrected ages). At each visit standardized normative measures of child development (Bayley Scales), maternal psychological distress (Brief Symptom Inventory), parenting stress (Parenting Stress Index), and (at 2 and 3 years) family impact (Impact on Family Scale) were given to assess the relationship of high/low risk VLBW birth on maternal and family stress. Groups did not differ in sex, race, socioeconomic status, or age. Group differences over time were assessed using repeated measures MANOVAS, with significant group and time (all Fs 3.5, ps <.05) effects found on all outcomes. Maternal psychological symptoms were elevated for both HR and LR groups neonatally but by 2 and 3 years, LR mothers had the lowest levels of symptoms, while HR mothers reported greater distress. Parenting stress did not differ until 3 years when HR mothers reported greater stress related to child characteristics. After the neonatal period, LR mothers did not differ from T mothers on any measure except for financial stress at 2 years, while HR mothers reported higher stress in family impact domains. Severity of maternal mental health symptoms was inversely related to child developmental outcome at all ages for HR mothers. These findings indicate that the psychosocial impact of VLBW birth varies with the medical risk, developmental outcome, and age of the infant.