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Biomedical subjects

C Hammerman

Publications and source records attributed to C Hammerman.

89 records · Page 5Linked to original sources
PubMed1987

Failure of prophylactic indomethacin to improve the outcome of the very low birth weight infant.

Prophylactic closure of the patent ductus arteriosus (PDA) has been recommended as a means of decreasing early respiratory distress, and thereby chronic respiratory sequelae in the very low birth weight (VLBW) neonate. This study was undertaken to evaluate some possible mechanisms for the observed failure of early indomethacin therapy to achieve such improvement. 24 VLBW infants with echocardiographic evidence of PDA were randomized to receive either indomethacin or placebo at 48 h of life; and then they were studied for clinical, metabolic and laboratory signs of ductal constriction and/or reopening. Early indomethacin conferred no improvement in respiratory sequelae. However, this was not secondary to a short-term therapeutic failure. Prophylactic indomethacin, even in the VLBW infant, was successful in decreasing dilator prostaglandin production, and probably in closing the PDA and in decreasing the number of recurrences. The implications are that even with effective ductal constriction, overall morbidity is not affected.

Double-Blind Method↗
PubMed1986

Prostaglandin levels: predictors of indomethacin responsiveness.

Pretreatment plasma dilator prostaglandin levels were measured in 16 premature infants with patent ductus arteriosus in an attempt to correlate abnormally elevated levels with clinical responsiveness to indomethacin therapy. Nine of the 16 infants responded well to indomethacin, with complete disappearance of their murmurs by 48 h. Eight of these nine infants had elevated baseline 6 keto PGF1 alpha levels (greater than 500 pg/ml). In contrast, seven of the 16 infants did not respond to indomethacin, and six of these had 6 keto PGF1 alpha within the normal range (less than 500 pg/ml). PGE2 levels varied in the same general direction, but lacked the specificity and sensitivity of the 6 keto PGF1 alpha levels. Thus, 6 keto PGF1 alpha levels seem to correlate with, and may eventually be helpful in predicting, clinical indomethacin responsiveness in the premature neonate with patency of the ductus arteriosus.

6-Ketoprostaglandin F1 alpha↗
PubMed1986

The silent ductus: its precursors and its aftermath.

Prophylactic closure of the patent ductus arteriosus has been recommended as a means of decreasing the morbidity of the very low birth weight neonate. This study was undertaken in order to determine potential risk factors involved in the development of the silent ductus, its impact upon both the early cardiorespiratory symptomatology and the subsequent morbidity of the premature neonate, and finally the potential benefit to be derived from prophylactic closure in this presymptomatic stage. Infants with birth weights of 1000 g or less were studied on days 2-3 of life echocardiographically, clinically, and with determination of plasma dilator prostaglandin levels. On entry to the study, those infants with early evidence of silent left-to-right patent ductus arteriosus (PDA) shunting were randomized to receive either prophylactic indomethacin or placebo therapy. Those infants with no evidence of ductal shunting were not treated at all. Infants with silent PDAs had elevated levels of the dilator prostaglandin metabolite 6-keto PGF1 alpha on admission, although they had no echocardiographic abnormalities. No other risk factors for PDA development could be identified. Silent PDA infants had an increased incidence of subsequent symptomatic PDAs, and overall morbidity and mortality when compared with those with no evidence of PDA (silent or symptomatic). Prophylactic ductal closure decreased the incidence of subsequent PDA development, but had no effect on overall morbidity and/or mortality.

6-Ketoprostaglandin F1 alpha↗
PubMed1986

Prostaglandins and echocardiography in the assessment of patent ductus arteriosus.

Prostaglandin (PG) levels and M-mode echocardiography were used to evaluate the severity of patent ductus arteriosus (PDA) in 19 premature infants. Mean 6-keto-PGF1 alpha levels in infants with more severe left-to-right shunting were significantly higher than those in infants with a moderate level of shunting (1335 +/- 763 vs. 504 +/- 348 pg/ml, respectively). Furthermore, there was a significant correlation between this elevation and a decrease in the left ventricular systolic time interval, suggesting that both reflect the severity of ductal shunting. Although other echocardiographic measurements of cardiovascular function generally showed some tendency to vary with 6-keto-PGF1 alpha levels, none was as closely correlated with the extent of PG elevation. Levels of PGE2 also seemed to vary with PDA severity; however, this correlation was not as significant.

6-Ketoprostaglandin F1 alpha↗
PubMed1985

Severe hyponatremia with indomethacin--a more serious toxicity than previously realized?

Five low-birth-weight neonates, ranging from 580 to 1,430 g, developed clinically significant hyponatremia (less than 130 mg/dl) within 48 h after being given indomethacin for patent ductus arteriosus closure. The extent of this hyponatremia is much more severe than previously reported. This group of infants is compared to another group of 5 patients who received indomethacin but did not develop severe hyponatremia. Several possible explanations for the observed differences are explored.

Ductus Arteriosus, Patent↗
PubMed1984

Indomethacin and the cardiopulmonary adaptations of transition.

The present investigation examines the biochemical and physiologic changes produced in fetal rabbit lungs by adding a prostaglandin synthetase inhibitor, sodium indomethacin trihydrate, to the pulmonary perfusate. A control group was similarly perfused without adding indomethacin. The ductus arteriosus was ligated and perfusion was then continued for 2 h while pulmonary artery pressures were monitored. At the end of this period, with perfusion continuing, the lungs were inflated with air at 5 cm H2O increments. Volume changes were recorded. After deflation, the lungs were lavaged with normal saline. Phospholipids were extracted from lung homogenates and lavage. Total lipid phosphorus was determined. Pulmonary vascular resistances in both groups manifested a sharp increase in pressure with ligation of the ductus. After 2 h of perfusion, pulmonary pressures in the control groups had returned very nearly to preligation levels, while in the indomethacin-treated group, pulmonary pressures remained significantly elevated. The first full inflation produced a slight fall in pulmonary vascular resistance in all control animals and a slight rise in all the treated rabbits. Perfused but untreated lungs had higher volumes during inflation as compared to both indomethacin-perfused lungs and unperfused untreated lungs. In this model, prostaglandins appear to have a significant role at two key points in transition: 1) the gradual accommodation to mechanically or hemodynamically mediated increases in pulmonary vascular resistance and 2) the drop in pulmonary vascular resistance which occurs with the first inflation of the lungs. No direct effect of prostaglandin inhibition on surfactant production was documented.

Animals↗
PubMed1981

Comparative measurements of phototherapy: a practical guide.

Increasing the dose of administered phototherapy has been shown to increase the rate of bilirubin decrement up to a saturation point beyond which no further increases in bilirubin degradation are observed. This study provides irradiance measurements which can be used to interpret phototherapy dose-response and saturation data clinically and to determine an optimal phototherapy lamp combination for maximal bilirubin degradation.

Bilirubin↗
PubMedDate not supplied

Accelerated weight gain by infants with pulmonic stenosis.

Retrospectively we compared the weight gain of infants who had significant valvular pulmonic stenosis with the growth of infants who had mild pulmonic stenosis and small ventricular septal defects. Our results indicate that the infants with significant pulmonic stenosis gained weight exceptionally well in comparison with others.

Heart Septal Defects, Ventricular↗
PubMedDate not supplied

Femoral hypoplasia--unusual facies syndrome: prenatal ultrasonographic observations.

FH-UFS is a rare syndrome characterized by bilateral femoral hypoplasia, together with facial dysmorphism. To the best of our knowledge, this is the first report describing prenatal ultrasonographic findings and in utero growth pattern of an infant with FH-UFS. Via analysis of our data it appears that the growth of the femur in our case was normal until the 24th week of pregnancy, at which time some in-utero insult occurred, resulting in temporarily arrested femoral growth. From the 34th week of pregnancy onward femoral growth rates returned to normal. We assume, therefore, that the etiology of FH-UFS is multifactorial. Only a combination of some hereditary proclivity, together with an intrauterine insult (possibly viral) could explain the appearance in the same fetus of cleft palate, developing at the 7th week of gestation, and a time-specific (25-32 weeks) disturbance of femoral growth.

Abnormalities, Multiple↗
PubMedDate not supplied

Patent ductus arteriousus in the premature neonate: current concepts in pharmacological management.

In utero, the ductus arteriosus shunts deoxygenated blood away from the pulmonary artery and towards the placental circulation where foetal gas exchange occurs. As a result of an intricately intertwined network of both physiological and biochemical changes, this vessel constricts rapidly after birth. Deoxygenated blood is diverted away from the placenta and through the lungs now vital for gas exchange. Premature closure of the ductus in utero can cause pulmonary hypertension and even death. Conversely, failure to close after birth can exacerbate respiratory distress, precipitate congestive heart failure and increase the risk of subsequent intestinal ischaemia leading to necrotising enterocolitis, bronchopulmonary dysplasia, renal hypoperfusion and/or cerebral ischaemia. In this review we summarise current knowledge of the delicately orchestrated control of the ductus arteriosus, focusing on the role of cyclo-oxygenase isoforms on prostaglandin production, on the interaction between prostaglandins and oxygen, and on the effects of these on ductal patency. We also seek to describe some of the standard and nonstandard therapeutic approaches available to the clinician when natural closure fails, reviewing alternative protocols for indomethacin administration and comparing indomethacin treatment with newer approaches such as ibuprofen. In summary, we will follow the course of this unique blood vessel as it is transformed over several hours from an organ absolutely vital to survival into programmed obsolescence.

Anti-Inflammatory Agents, Non-Steroidal↗
PubMedDate not supplied

Pediatric coverage of the delivery room: an analysis of manpower utilization.

OBJECTIVES: To determine the frequency and pattern of pediatric calls to the delivery room and the actual type of medical care administered to the newborn in the delivery room. STUDY DESIGN: This was a prospective observational study of 2554 births in a university-affiliated tertiary care hospital. Existing protocols required the attendance of a pediatric resident or neonatal fellow at all deliveries other than uncomplicated vaginal term births. The pediatrician's activity in the delivery room was characterized as either "medical care" or "minimal care." Results were analyzed by diagnostic category. RESULTS: Pediatricians attended 646 of the deliveries (25%). Medical care was administered in 204 of the deliveries, representing 31% of the time they were at a delivery and 8% of all deliveries. The three major indications for pediatric delivery room attendance were cesarean sections (n = 253; 39%), presence of meconium in amniotic fluid (n = 117; 18%), and vacuum deliveries (n = 117; 18%). Medical care was required only in 1 of 56 cases of elective repeat cesarean sections, in 1 of 20 cases of a cesarean section for nonprogress of labor, and in 1 of 38 cases when thin meconium was present. In contrast, medical care was needed in 52 of 81 (64%) cases of cesarean sections for fetal distress, in 11 of 11 (100%) of the cesarean sections for multiple births, and in 67 of 89 (85%) cases of thick meconium (p < 0.05). There was a need for medical attendance after the birth in less than 1% of 1908 cases for which the pediatrician was not initially called to delivery room. CONCLUSION: Because their medical skills were needed only one of three times that pediatricians were called to the delivery room, and then mostly in specific risk situations, more selective use of pediatric manpower for delivery room coverage may lead to a more efficient use of medical resources without any apparent increase in patient morbidity.

Cost-Benefit Analysis↗
PubMedDate not supplied

Favism by proxy in nursing glucose-6-phosphate dehydrogenase-deficient neonates.

Two nursing neonates deficient in glucose-6-phosphate dehydrogenase developed severe hyperbilirubinemia despite phototherapy. Mothers of both the infants had recently eaten fava beans. The hemolytic triggers found in fava beans may have been absorbed by the mothers and excreted in their breast milk. Carboxyhemoglobin determination performed on one of the infants reflected ongoing hemolysis.

Breast Feeding↗