Treatment decisions for newborns at the threshold of viability: an ethical dilemma.

The major ethical issues involved in decision-making in the care of extremely low birth weight newborns are analyzed here. We propose a schema for assessment and management of these infants that is consistent with ethical principles broadly accepted by the pediatric community, and which takes into account mortality risk at any given institution rather than arbitrary weight limits, with a major decision-making role for the infant's parents. When possible, the decision of whether or not to resuscitate should be made before delivery; when not possible, delivery room resuscitation is recommended, and the decision to continue or withdraw care should be made subsequently based on likelihood of survival and the wishes of the parents.

Evaluation of neonates born with intrauterine growth retardation: review and practice guidelines.

Intrauterine growth retardation affects approximately 10% of live-born infants. Causes of intrauterine growth retardation are heterogeneous, and frequently the care of these infants poses a diagnostic and therapeutic challenge. Diagnosis of impaired fetal growth is an area in which close collaboration among the obstetrician, pediatrician, and dysmorphologist is essential for proper care of these newborns. It is axiomatic that the best way to care for these infants is to establish an accurate diagnosis prenatally or soon after birth and to manage on that basis. An algorithm for evaluation and management of intrauterine growth retardation that is based on available empiric data is presented. These guidelines are intended to guide medical practice and not to replace clinical judgment.

Effects of theophylline on renal function in premature infants.

Xanthines are frequently being used in the management of premature babies. Studies in adult subjects have demonstrated a diuretic effect of aminophylline due to the inhibition of solute reabsorption in various segments of the nephron. We evaluated the effects of aminophylline on the developing kidney. Nineteen premature infants, with a mean +/- SD gestational age of 31.1 +/- 2.8 weeks and mean birth weight of 1481 +/- 454 g were studied at mean age of 4.5 +/- 4.0 days before and after a 20-minute loading infusion of 6 mg/kg aminophylline, followed by maintenance therapy at a dose of 2 mg/kg every 12 hours. A marked diuresis occurred immediately after the loading dose, the ratio of urinary output to water intake increased from 0.58 +/- 0.36 to 1.19 +/- 0.65. Concomitantly, the fractional excretion of sodium increased from 2.7 +/- 2.6% to 5.7 +/- 4.4% and that of potassium rose from 21 +/- 19% to 31 +/- 21%. Urinary calcium and uric acid excretion were also enhanced: calcium to creatinine ratio rose from 0.31 +/- 0.29 to 0.60 +/- 0.54 and uric acid to creatinine ratio increased from 2.5 +/- 1.5 to 3.8 +/- 2.0. Tubular reabsorption of phosphorus (TRP) was not affected. Most of the effects were no longer evident after 24 hours, despite continuing aminophylline maintenance therapy. In premature infants the aminophylline loading dose, but not maintenance therapy, affected renal functions. Because heart rate, blood pressure, and creatinine clearance did not change, it appears that aminophylline acts directly on tubular reabsorptive functions.

Management of neonates born to mothers with group B streptococcus colonization.

Approximately 20% of pregnant women harbor group B streptococcus (GBS) in the lower genital tract at the time of delivery. Intrapartum chemoprophylaxis of mothers with GBS colonization who have risk factors for neonatal GBS at delivery improves the outcome of the neonates. The recommendations for treating newborn infants of mothers who receive intrapartum chemoprophylaxis for GBS colonization and the recommendations for those who do not remain empiric, because clinical studies to support such recommendations are not available. An algorithm for treatment of neonates born to mothers with GBS colonization that is based on available data and empiric recommendations is presented. These guidelines are intended to guide medical practice and not to replace clinical judgment.

Evaluation of hypothalamic-pituitary-adrenal axis in premature infants treated with dexamethasone.

Results of a national survey of the current use of steroids in newborns in 1993 showed that 95% of the neonatologists in the United States have used dexamethasone for neonates at risk for chronic lung disease. Dexamethasone therapy for a period of a week or longer is associated with suppression of the hypothalamic-pituitary-adrenal axis (HPAA) in a substantial number of premature infants. A review of our current understanding of the biochemical tests evaluating HPAA function in premature infants and suggested guidelines for HPAA evaluation and management following dexamethasone therapy are presented.

Management of premature infants with extensive bowel resection with high volume enteral infusates.

To avoid long-term parenteral nutrition (PN), three premature infants with extensive bowel resections were fed high volume enteral infusates (HVEI). Following surgery an elemental hypo-osmolar gastric infusate was initiated. The infants were weaned of PN and were subsequently maintained on HVEI feeding. Rather than using the volume of the ileostomy outputs or the presence of reducing substances as guides for adjustment of enteral intake, we tolerated large ileostomy output and focused instead on the patients' hydration, serum electrolytes and acid base status. During HVEI feeding, the patients had sustained weight gain, while the mean +/- SD enteral intakes were 373 +/- 67, 689 +/- 132, and 415 +/- 108 ml/kg per day; osmolarity of enteral infusates were 250 +/- 25, 225 +/- 40 and 228 +/- 27 mosmol/l; caloric intakes were 163 +/- 29, 258 +/- 54, and 153 +/- 44 Kcal/kg per day; and ileostomy outputs were 113 +/- 47, 228 +/- 59, and 175 +/- 69 ml/kg per day, respectively. Gut adaptation lasted 122, 141, and 205 days, respectively. Re-anastomoses of the intestines were performed at the ages of 8, 78, and 36 months. At 18, 108, and 58 months, infants' weights were in the 50th, 20th, and 5th percentiles, respectively. No infant developed cirrhosis. High volume enteral infusate feeding in infants with extensive bowel resection may help achieve gut adaptation and may serve as an alternative nutrition modality to prolonged PN.

Comparison of arterial and capillary bilirubin values in neonates with arterial lines.

To determine whether arterial and capillary values for bilirubin agree in neonates, we analyzed 35 simultaneously sampled capillary and arterial specimens from 13 infants. We found a high correlation between arterial and capillary bilirubin values (r = 0.993). We conclude that arterial bilirubin samples may be substituted for capillary samples in newborn infants.

Central venous line thrombosis in premature infants: a case management and literature review.

Increased risk of central venous line thrombosis in tiny premature infants occurs because the size of the catheter relative to the cross-sectional area of the vessel is large, decreased plasma levels of plasminogen and antithrombin III, and relative low flow of the infusate through the catheter, in comparison with larger infants. A potentially fatal complication of central venous catheters is an intracardiac thrombus. The yield of detecting right atrial thrombi by routine echocardiographic monitoring is very low. Persistent positive blood cultures in infants with central venous lines, in spite of appropriate antibiotic therapy, or signs of catheter occlusion, may increase the yield of echocardiographic detection of intracardiac thrombi. Surgical removal of intracardiac thrombi in infants weighing less than 1500 gm carries a high mortality rate because of the need to use cardiopulmonary bypass with total circulatory arrest and profound hypothermia during surgery. It is in these infants that thrombolysis with urokinase should be considered. A successful therapy with urokinase of a complete occlusion of the right pulmonary artery by an embolus originating from the right atrium is described in a premature infant. For thrombolysis, a loading dose of urokinase of 4400 U/kg followed by 4400 to 8800 U/kg/hr for a few days was used. The thrombolytic effect was manifested by decreased thrombus echogenicity followed by its disappearance, by increased fibrinogen split products, and by decreased plasma fibrinogen. Urokinase therapy may cause massive bleeding, dislodge an intracardiac thrombus causing obstruction of cardiac valves or main vessels or causing embolization to the pulmonary or systemic circulation.(ABSTRACT TRUNCATED AT 250 WORDS)

The clinical utility of serum creatinine measurement vs calculated glomerular filtration rate in the assessment of renal function in the premature infant.

The ability to assess the glomerular filtration rate (GFR) without the necessity of collecting urine in premature infants would be of significant clinical benefit. In 1986, the modified Schwartz formula (MSF = 0.33 x length (cm)/plasma creatinine (mg/dL)) was developed. In the MSF, GFR was estimated in premature infants during the first post-natal year. The goal of the present study was to test the applicability of the MSF in premature infants during the neonatal period and to evaluate the clinical use of serum creatinine (Cr) as a predictor of GFR. In 42 premature infants of mean (+/-SD) birthweight 1506.6 (+/-388.8) g, gestational age 31.3 (+/-1.7) wks and post-natal age 14.7 (+/-8.3) d, the correlation between GFR, estimated by endogenous creatinine clearance (ECrC), was compared with the serum Cr and with GFR estimated by the MSF. The correlation coefficient between ECrC and serum Cr was 0.6789 and between estimated GFR derived from ECrC and MSF, 0.4657. In premature infants during the neonatal period, serum Cr has a better correlation with GFR than with MSF. When serum Cr is less than 0.9 mg/dL, the 95% confidence interval suggests that at least 89% of the infants can be expected to have an ECrC within the normal range.

Noninvasive medical management of fungus ball uropathy in a premature infant.

Unilateral renal obstruction secondary to fungus balls is described in a premature infant. Noninvasive medical management, which included amphotericin B and 5-flucytosine therapy and forced diuresis, resulted in disappearance of fungus balls and resolution of the obstruction.

Hypothalamic-pituitary-adrenal axis function in very low birth weight infants treated with dexamethasone.

The effect of dexamethasone therapy on hypothalamic-pituitary-adrenal axis function was prospectively investigated in very low birth weight infants with bronchopulmonary dysplasia. Ten infants (mean +/- SD birth weight 825 +/- 265 g, gestation 25.8 +/- 1.9 weeks, postnatal age 33.1 +/- 17.7 days) initially received intravenous dexamethasone, 0.5 mg/kg per day for 3 days, and then were weaned over a period of 45 +/- 19.0 days to a replacement dose, followed by a metyrapone test. Morning plasma cortisol and 11-deoxycortisol levels were measured before and after an oral metyrapone dose given at midnight. Five infants (group A: birth weight 876 +/- 313 g, gestation 26.2 +/- 1.3 weeks, age of entry 31.8 +/- 22.8 days) had normal metyrapone test results, and five infants (group B: 778 +/- 234 g, 25.4 +/- 2.5 weeks, 34.4 +/- 13.4 days) had suppressed test results. Group A infants, in comparison with group B infants, had higher basal cortisol plasma levels (14.52 +/- 12.53 and 3.00 +/- 1.38 micrograms/dL, P = .047), higher postmetyrapone 11-deoxycortisol plasma levels (3.11 +/- 3.93 and 0.55 +/- 0.51 micrograms/dL, P = .028), larger differences between basal and postmetyrapone cortisol levels (7.10 +/- 4.67 and 2.12 +/- 1.31 micrograms/dL, P = .047), and larger differences between basal and postmetyrapone 11-deoxycortisol levels (2.99 +/- 3.93 and 0.29 +/- 0.25 micrograms/dL, P = .009). The hypothalamic-pituitary-adrenal axis function in group B infants eventually returned to normal when they continued to receive low-dose dexamethasone therapy after a period of 36.8 +/- 16.6 days.(ABSTRACT TRUNCATED AT 250 WORDS)

Prevention of hypogammaglobulinemia of prematurity with intravenous immune globulin.

We evaluated the effect of 1 g/kg intravenous immune globulin (IGIV) on immunoglobulin levels and half-life, the dose and frequency of IGIV administration necessary to maintain IgG levels at greater than 400 mg/dL, and IGIV effect on immunoglobulin levels after discharge in infants less than or equal to 32 weeks' gestation and less than or equal to 1500 g. Fifteen infants received 31 infusions at IgG levels less than or equal to 400 mg/dL. Immunoglobulin levels were obtained 24 hours postinfusion, weekly during hospitalization, and monthly after discharge. Mean IgG postinfusion was 980 mg/dL. Mean IgG half-life was 18 days (range 7 to 41). Smaller infants with greater than or equal to 5% of blood volume removed per week experienced shorter immunoglobulin half-lives. IGIV caused increased IgG levels after discharge and did not delay endogenous production of IgG. We conclude that 1 g/kg IGIV given to infants less than or equal to 32 weeks' gestation and less than or equal to 1500 g every 1 to 6 weeks during hospitalization, depending on weight and blood volume removed, prevents hypogammaglobulinemia of prematurity.

Anencephalic infants: life expectancy and organ donation.

Between 1978 and 1982, 205 anencephalic infants weighing more than 2,500 g were born alive in California. Although typically none were offered significant support, almost 9% lived more than one week. It seems reasonable to assume that modern intensive care would have increased survival times dramatically. In fact, preliminary data from centers specializing in neonatal organ transplantation demonstrate that seven to 14 days of ventilatory support can be accomplished for anencephalic infants without occurrence of brainstem death. Given these data and medical information that clearly establishes anencephalic infants as a "special case" of children who have not suffered brain death but could reasonably be used as organ donors, we believe that parents who wish to do so should be allowed to continue ventilatory support for their anencephalic children for whatever period of time is necessary to find organ recipients and arrange for organ donation. Arbitrary cutoff points for intensive care and artificial criteria for brain death should not be necessary to allow the use of anencephalic infants as organ donors. We believe that current laws should be changed to permit this scenario.

Critical tricuspid insufficiency due to papillary muscle rupture. A result of prenatal hypoxic insult.

Fatal tricuspid insufficiency secondary to papillary muscle rupture due to prenatal hypoxic insult occurred in a full-term newborn. The diagnosis of flail tricuspid valve should be considered when fetal distress is encountered in a newborn with persistent hypoxemia. Prenatal diagnosis of this condition combined with prompt delivery, prostaglandin E1 therapy, and possible surgical repair of the tricuspid valve may improve chances of survival.

Changing attitudes of neonatologists toward ventilator support.

Two identical questionnaires were completed by neonatologists in Southern California, one in 1979 and the other in 1985. All questions addressed only the issue of ventilator support. Respondents were asked to assume both parents wished ventilator support withheld or discontinued. In 1985, despite parents' wishes, neonatologists were more willing to start and continue ventilator support in smaller and less mature infants than in 1979. In 1985, but not 1979, respondents frequently would use ventilator support significantly more than they thought they should. Additionally, in both 1979 and 1985 it was more difficult for respondents to withhold ventilator support in infants with acquired versus congenital problems.

Spontaneous regression of cardiac rhabdomyoma in tuberous sclerosis.

Life-threatening cardiac rhabdomyoma in a newborn infant regressed spontaneously within a 5 month period. Since cardiac surgery for rhabdomyoma is dangerous in infancy, medical management should be considered if symptomatology is not severe. When a fetal arrhythmia is diagnosed, antenatal ultrasound examination for presence of cardiac tumors is warranted.