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Biomedical subjects

S Shankaran

Publications and source records attributed to S Shankaran.

At least 73 records · Page 4Linked to original sources
PubMed1986

Pharmacokinetic basis for antenatal dosing of phenobarbital for the prevention of neonatal intracerebral hemorrhage.

The transplacental and elimination pharmacokinetics of phenobarbital administered antenatally was analyzed in both mothers and infants as part of a study evaluating the efficacy of antenatally administered phenobarbital in the prevention of neonatal intracerebral hemorrhage. Twenty-five pregnant women in labor less than 35 weeks' gestation received 500 mg phenobarbital administered intravenously. The maternal serum phenobarbital level at delivery was 8.76 +/- 1.99 micrograms/ml and cord serum phenobarbital level was 9.0 +/- 1.75 micrograms/ml (all values are mean +/- SD). There was no correlation between the time from phenobarbital administration to delivery (5.6 +/- 4.6 h) and the cord:maternal serum phenobarbital ratio (1.05 +/- 0.21) (r = -0.03; p greater than 0.05). The mean apparent half-life of phenobarbital estimated in 11 infants was 175.5 +/- 45.6 h. The present study documents the ability to predict serum levels in the fetus and neonate from the serum concentrations achieved in the mother.

Cerebral Hemorrhage↗
PubMed1985

Normal values for ventricular size as determined by real time sonographic techniques.

Seventy-three real time sonographic scans were performed through the anterior fontanelle of 67 infants between 28 and 48 weeks post-conception who had no evidence of intracranial disease. Several anatomical measurements were plotted against independent variables such as post-conception age, weight and head circumference at the time of the examination. All of the measurements increased as age, weight and head circumference increased. Ratios formed by dividing transventricular diameters by transcalvarial diameters at the two levels in the coronal plane and by dividing occipital mantle thickness by frontal mantle thickness in the parasagittal planes remained stable as all of the independent variables increased. In 88% of cases the occipital mantle could not be measured since the occipital horns of the lateral ventricles could not be identified. Since dilation of the ventricular system starts in the occipital horns of the lateral ventricles, non-visualization of this area is an important negative finding.

Body Weight↗
PubMed1985

The effect of multiple exchange transfusions on bilirubin binding.

Three bilirubin binding tests (hydroxybenzene-azobenzoic acid dye binding method, the estimation of unbound bilirubin by horseradish peroxidase assay and the saturation of albumin by the salicylate saturation index) were performed on pre-exchange samples of blood and repeated 24 hours after the procedure. No significant improvement in bilirubin binding was found even in infants receiving as many as four exchange transfusions. Based on these bilirubin binding tests, we find no evidence that the criteria for subsequent exchange transfusions should be different from the first exchange transfusion.

Azo Compounds↗
PubMed1984

Ultrasound in the evaluation of hypoxic-ischemic injury and intracranial hemorrhage in neonates: the state of the art.

The ultrasonic diagnosis of hypoxic-ischemic injury and intracranial hemorrhage in neonates is reviewed. The technical and pertinent anatomical data are presented. The need to diagnose parenchymal lesions is emphasized. A sonographic classification as well as current recommendations for evaluation of intracranial contents in neonates suspected of hypoxic-ischemic injury and/or hemorrhage are presented.

Brain↗
PubMed1984

Use of chloramphenicol palmitate in neonates.

The absorption and disposition of orally administered chloramphenicol palmitate (chloramphenicol-P) was studied in seven neonates (four preterm, three term). The highest measured chloramphenicol serum concentrations occurred greater than or equal to 4 hours after the dose, and ranged from 5.5 to 23 micrograms/ml after doses of chloramphenicol-P 50 mg/kg/day orally. The dosage had to be increased in all preterm neonates from 25 mg/kg/day to 50 mg/kg/day to obtain adequate serum levels during therapy. In four neonates the apparent half-life could not be estimated, because there was no decline in serum concentrations. The apparent half-life was 3 and 6 hours, respectively, in two neonates in whom the serum concentration declined during the dosing interval. Urinary excretion of chloramphenicol and the glucoronide ester in three neonates varied from 24% to 55% of the total dose administered. These preliminary data suggest considerable variability in serum chloramphenicol levels when chloramphenicol-P is administered orally in neonates. The delay in achieving the maximum serum concentration, nondeclining serum curve, and low renal recovery is indicative of incomplete, prolonged, and erratic absorption, possibly related to delayed gastric emptying or decreased intraluminal hydrolysis of the palmitate ester.

Administration, Oral↗
PubMed1984

Intracranial hemorrhage in the hypoxic-ischemic infant: ultrasound demonstration of unusual complications.

Seven neonates (four preterm and three term) with severe hypoxic-ischemic parenchymal brain changes are presented to illustrate the kinds of parenchymal lesions demonstrable on ultrasound, to show the similarity of parenchymal lesions in preterm and term infants, and to correlate the severe neurologic deficits with the parenchymal changes. The lesions demonstrated are periventricular leukomalacia, large-vessel infarction, isolated parenchymal hemorrhage, multiple cystic encephalomalacia, and parenchymal atrophy. Parenchymal changes should be sought in such infants during any stage of their disease.

Brain↗
PubMed1984

Severe bronchopulmonary dysplasia. Predictors of survival and outcome.

Predictors of survival and outcome were evaluated following severe bronchopulmonary dysplasia in 35 neonates, 15 of whom died during the initial hospitalization and four following discharge. There was no difference in the clinical characteristics between those infants who survived or died. The survival rate was 47 percent when the length of stay in the hospital was three months and was 17 percent when the length of stay was five months. The survival rate was 27 percent when the time receiving oxygen was three months. There were no survivors when the time receiving oxygen was longer than five months. Follow-up of 13 survivors revealed that four had neurologic sequelae, and two had severe retrolental fibroplasia. When comparing infants with a mean mental developmental index of less than 84 (n = 8) to those with more than 85 (n = 5) on the Bayley Scales of Infant Development, mean length of hospitalization was 125 days vs 72 days (p less than 0.05), and the time receiving oxygen was 84 days vs 46 days (p less than 0.05). When comparing infants with growth parameters below the 5th percentile (n = 4) to those above the 5th percentile (n = 9), the mean time receiving oxygen was 94 days compared to 58 days (p less than 0.05). Severe bronchopulmonary dysplasia is associated with a high mortality and morbidity, both in and beyond the neonatal period.

Birth Weight↗
PubMed1984

Effect of prophylactic phenobarbital on intraventricular hemorrhage in high-risk infants.

Forty-two premature infants less than 24 hours of age, with normal admission echoencephalograms, were randomly assigned to control or phenobarbital treatment groups. Infants in the treated group received two loading doses of 10 mg/kg of phenobarbital 12 hours apart, followed by a maintenance dose of 2.5 mg/kg every 12 hours for 6 days. Serial echoencephalograms were obtained in both groups. The groups were comparable with regard to birth weight, gestational age, and potential risk factors for subependymal-intraventricular hemorrhage. Ten infants (48%) in each group developed hemorrhage. The hemorrhages in the phenobarbital-treated group were significantly less severe than those in the control group. The phenobarbital-treated infants who bled, however, were also significantly larger and more mature than control infants who bled. The results of this study indicate no effect of phenobarbital on the incidence of subependymal-intraventricular hemorrhage, but a possible beneficial effect on the severity of hemorrhage.

Cerebral Hemorrhage↗
PubMed1982

beta-hemolytic streptococcal infection appearing as persistent fetal circulation.

Sixty neonates who were transferred to a neonatal intensive care unit during a four-year period had diagnoses of persistent fetal circulation (PFC). Six of these 60 neonates had beta-hemolytic streptococcal infection. The clinical appearance of these six neonates included respiratory distress, cyanosis, and/or apnea. The chest roentgenograms showed mild to moderate lung disease. All six neonates had progressive acidosis with hypoxemia. The diagnosis of PFC was made by cardiac catheterization or contrast echoangiography. The neonates were treated with mechanical ventilation, antibodies, and supportive therapy, including tolazoline hydrochloride. Mortality was high; only one of the six neonates survived. Streptococcal infection should be added to the growing list of conditions associated with PFC.

Apnea↗
PubMed1982

Sonographic classification of intracranial hemorrhage. A prognostic indicator of mortality, morbidity, and short-term neurologic outcome.

Sixty-two neonates diagnosed to have periventricular-intraventricular hemorrhage were classified by sonographic findings as follows: mild, confined to the subependymal region or accompanied by a small amount of blood in the normal-sized lateral ventricle (10); moderate, intermediate amount of blood in the enlarged lateral ventricle (26); and severe, hemorrhage filling the entire ventricle forming a cast (12) or intraventricular hemorrhage with an intracerebral extension (14). Twenty-six of 35 surviving neonates had posthemorrhagic hydrocephalus, and 11 infants required shunt insertion. The survival rate of neonates with periventricular-intraventricular hemorrhage and the incidence of posthemorrhagic hydrocephalus correlated with the severity of the hemorrhage (P less than 0.05). The highest mortality rate was seen in the group with ventricular casts. All surviving neonates with casts developed hydrocephalus. All surviving neonates with intracerebral hemorrhage developed porencephaly. The severity of the hemorrhage correlated with short-term neurologic outcome (P less than 0.05), the group most severely affected being the one with intracerebral extension of hemorrhage. The severity of the hemorrhage also correlated with abnormal ventricular size by sonography on follow-up (P less than 0.05). However, posthemorrhagic hydrocephalus and abnormal ventricular size on follow-up did not correlate with neurologic outcome in the moderate and severe hemorrhage groups.

Cerebral Hemorrhage↗
PubMed1982

Indomethacin and bilirubin-albumin binding.

We studied the effects of indomethacin on the bilirubin binding of albumin using the hydroxybenzene azobenzoic acid (HBABA) dye binding method, the estimation of unbound bilirubin concentration (UBC) by the horseradish peroxidase assay and the whole blood fractionation (WBF) technique. The addition of up to 2 micrograms/ml of indomethacin, which is the level obtained with an 0.2 mg/kg dose, did not decrease the mean HBABA dye binding capacity of 29 icteric sera or increase the mean UBC of 11 icteric sera. There was also no additional displacement of bilirubin in 5 icteric sera measured by the WBF technique. However, the addition of 10-40 micrograms/ml of drug, which is the level that would be achieved if a 2 mg/kg dose of indomethacin were administered, resulted in a significant reduction of HBABA in 15 icteric sera (81.74-57.3%, p less than 0.005) and a significant increase of UBC in 11 icteric sera (6.17-37.2 nM/l, p less than 0.001). Therefore, no displacement of bilirubin from albumin occurred in the presence of usual therapeutic level of indomethacin; higher levels displaced bilirubin.

Bilirubin↗
PubMed1980

Patent ductus arteriosus in hyaline membrane disease: chest radiography.

Sequential chest radiographs of 45 consecutive neonates with respiratory distress were reviewed prospectively. Nineteen had hyaline membrane disease, 16 had infiltrates of other etiology, three had transient tachypnea of the newborn, and seven had no pulmonary pathology on chest radiography. Ten of the 19 infants with hyaline membrane disease and one of the 16 with pulmonary infiltrates had clinical and radiologic evidence of a patient arteriosus; there was echocardiographic confirmation in seven. Radiologic evidence of the patent ductus arteriosus was detected in all cases with no false positives. The radiographic criterion of the patent ductus was the appearance in sequential frontal chest films of pulmonary plethora, that is, pulmonary vascular engorgement and perihilar edema "haze." The radiographic appearance of the patent ductus arteriosus was detected prior to the clinical signs in seven of 11 cases and simultaneously with the clinical picture in three cases. In one the radiographic abnormally occurred later. Chest radiography is a valuable adjunct in the early diagnosis of a patent ductus arteriosus in infants with hyaline membrane disease.

Ductus Arteriosus, Patent↗
PubMed1977

The displacement of bilirubin from albumin by furosemide.

Since furosemide, a sulfonamide diuretic, has been recommended for use in the newborn infant, a study was made of its effect on the bilirubin-binding capacity of albumin. Furosemide was compared to sulfisoxazole, a known displacer of bilirubin, by means of three methods. First, aliquots of whole blood from 20 icteric infants were diluted in phosphate buffer along with expected clinical concentrations of furosemide and sulfisoxazole. The red cells and globulins were then isolated and bilirubin concentrations were measured in these two fractions. The addition of Furosemide resulted in the displacement of bilirubin from albumin to red cells and globulins. Mole for mole, furosemide displaced bilirubin about as well as sulfisoxazole. Second, the hydroxybenzeneazobenzoic acid dye binding test of Porter and twaters was performed using the sera of eight jaundiced newborn infants. The mean dye binding capacity of the sera was significantly reduced with the addition of furosemide to a final concentration of 2 mug/ml. Third, the administration of furosemide (5 mg/kg) or sulfisoxazole (50 mg/kg) to adult Gunn rats resulted in a significant fall in mean serum bilirubin concentration compared to saline controls. Furosemide, like sulfisoxazole, is a potent displacer of bilirubin and should be used with caution in jaundiced infants.

Animals↗
PubMedDate not supplied

Feasibility of invasive monitoring of intracranial pressure in term neonates.

Seven term neonates with encephalopathy resulting from asphyxia and/or intracranial hemorrhage underwent invasive monitoring of intracranial pressure through the epidural or intracerebral space. The average age (in hours) at insertion of the monitor was 27 h in the 3 neonates with asphyxia and 70 h in the 4 neonates with hemorrhage. Intracranial hypertension was noted in 6 neonates. The management of the hypertension included hyperventilation followed by mannitol for pressures that were sustained above 20 mmHg and pentobarbital for pressures above 30 mmHg. The duration of the hypertension varied in 5 neonates from 4 to 72 h, while in the remaining neonates, the pressure remained elevated until death at 70 h. All 4 survivors with intracranial hemorrhage have minimal neuromotor deficits on follow up and 2 survivors with asphyxia have cognitive deficits and are microcephalic. From this small series, it appears that in the management of term neonates with intracranial hemorrhage, monitoring of intracranial pressure should be considered.

Asphyxia↗