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Biomedical subjects

I M Hiatt

Publications and source records attributed to I M Hiatt.

At least 37 records · Page 2Linked to original sources
PubMed1985

Serial lumbar punctures in prevention of post-hemorrhagic hydrocephalus in preterm infants.

We studied 47 infants with either grade 3 or grade 4 intraventricular hemorrhage, to assess the efficacy of intermittent lumbar punctures in the prevention of post-hemorrhagic hydrocephalus in a prospective controlled trial. The control group received supportive care only, whereas the treatment group additionally underwent intermittent spinal taps. The spinal taps were started at postnatal age 11 +/- 5 days and continued for 20 +/- 16 days, with the removal of 67 +/- 101 ml cerebrospinal fluid using 16 +/- 12 taps. The two groups were comparable with regard to birth weight, gestational age, race, sex, Apgar score, and severity of hemorrhage. Three infants in the control group died, compared with two infants in the study group. Nine infants in the control group and 10 infants in the study group developed hydrocephalus requiring a ventriculoperitoneal shunt or a ventricular catheter reservoir. These differences in the outcome in the two groups are not statistically significant. We conclude that serial lumbar punctures were unsuccessful in prevention of hydrocephalus in this group of preterm infants with intraventricular hemorrhage.

Cerebral Hemorrhage↗
PubMed1985

Pharmacokinetic evaluation of cimetidine in newborn infants.

The pharmacokinetics of cimetidine were studied in three newborn infants with reflux esophagitis or stress ulcer. One infant was given 5 mg/kg intravenously (IV), one was given 10 mg/kg IV, and one was given 10 mg orally. Serum concentrations 30 minutes after administration were 1.2 micrograms/ml, 5 micrograms/ml, and 4.2 micrograms/ml, respectively. Concentrations greater than 0.5 micrograms/ml were measured 1, 6, and 9 hours, respectively, after administration. The half-life of the drug ranged from 1.10 to 2.18 hours. These preliminary data suggest that a dose of 5 to 7 mg/kg would effectively suppress gastric acid secretion in neonates.

Cimetidine↗
PubMed1984

Investigation of a temporal cluster of left sided congenital heart disease.

During October and November 1977, eight newborns with critical congenital heart disease, six of these with left sided lesions, were admitted to a New Jersey newborn unit serving two predominantly rural counties with 9700 annual live births. The six left heart lesions (three cases of hypoplastic left heart, two of interrupted aortic arch, and one of aortic coarctation) represented 30% of all neonatal left sided lesions seen at the unit in the three year period 1976-8. The scan statistic for temporal clustering was significant (p less than 0.05). A case-control study was performed in which an average of four controls were matched to each case. A questionnaire was administered to the mothers of cases and controls concerning occupation, periconceptional and prenatal nutrition, radiation and chemical exposure, use of alcohol and tobacco, medications, immunisations, infections, and other exposures. No statistically significant differences between cases and controls were found on any of these items. Although no aetiology for this cluster of congenital heart anomalies could be found, it is of interest that three temporal clusters of fetuses or newborns with chromosomal trisomies have been reported in the medical literature whose conceptions were roughly contemporaneous with those of the infants in our series. These occurred in Rhode Island/Massachusetts, Maryland, and New York City. A speculative possibility is that these four point epidemics represented exposure to a common teratogenic agent, perhaps influenza B, in the winter of 1976/77 in the northeastern United States.

Aorta, Thoracic↗
PubMed1983

Transcutaneous bilirubinometry II. Dermal bilirubin kinetics during phototherapy.

We examined the effect of phototherapy on cutaneous bilirubin using the transcutaneous bilirubinometer (TcB) in 14 white infants at a mean postnatal age of 30 h. Six infants were treated with blue light, eight with white light. An opaque patch, 2.5 cm in diameter, covered the skin and served as a source for TcB control values. Simultaneous TcB measurements were obtained from exposed and patched areas every 15 min during 4 h of phototherapy. After the start of phototherapy, TcB index obtained from patched skin did not change during the course of treatment. Data from exposed skin showed that the initial rate of TcB index fall during the first hour was significantly faster than the successive values during the next 3 h in both groups studied. During the first 2 h of therapy the TcB index decreased faster among infants treated with blue light. Correlation studies indicate that TcB measurements from exposed skin areas may not be clinically useful in predicting serum bilirubin response to phototherapy but data obtained from unexposed sites may fill this role.

Bilirubin↗
PubMed1981

The effects of shielding the hepatic area on the clinical response to phototherapy.

The changes in serum bilirubin concentration in response to phototherapy were studied in 26 infants with and without an opaque patch on the liver area. Fifteen infants in the patched group were treated at a mean age of 50.7 h, and 11 control infants at 49.1 h. No significant differences were demonstrated between the two groups in duration of phototherapy, peak bilirubin concentration and rates of bilirubin decrement. Shielding the hepatic area during illumination does not alter the clinical response to phototherapy which suggests that the main site of action of phototherapy is in the skin.

Bilirubin↗
PubMed1981

Continuous monitoring of PO2 during apnea of prematurity.

We studied the changes in PO2 during 72 isolated episodes of apnea of prematurity in 20 low-birth-weight infants. A stable PO2 prior to the onset of apnea was observed in 65% of the episodes. A falling PO2 was noted in only 18% of the cases. The mean initial PO2 was 75 mm Hg and no infant was hypoxic (PO2less than 40 mm Hg) immediately prior to apnea. The mean PO2 fell to 60 mm Hg at the end of apnea and continued to fall to a mean low PO2 of 46 mm Hg. The mean PO2 at recovery was 79 mm Hg. We concluded that in this group of premature infants, hypoxia is not the initiating even in the apnea of prematurity. Furthermore, we noted that arterial oxygen tension continues to fall despite the reestablishment of respiratory efforts, that the rate of recovery from apnea is slower than the rate of fall, and that bradycardia associated with apnea is not initiated by hypoxemia.

Apnea↗
PubMed1981

Transcutaneous bilirubinometry. I. Correlations in term infants.

The transcutaneous bilirubinometer was evaluated in 43 white infants, eight black infants, and in nine white infants treated with phototherapy. The reproducibility of the instruments was determined after trials consisting of both five and 100 repetitions. Among the infants not being treated with phototherapy, TcB index and serum bilirubin concentration correlated at 0.90 level in both white and black infants. Phototherapy reduced the accuracy of the TcB and, at the present time, the use of this index in infants under light therapy cannot be recommended. Otherwise the TcB is a valuable tool in screening healthy term infants for hyperbilirubinemia.

Bilirubin↗
PubMed1981

The effect of continuous positive airway pressure on the course of respiratory distress syndrome: the benefits on early initiation.

The course of idiopathic respiratory distress syndrome (IRDS) treated with continuous positive airway pressure (CPAP) was studied in 38 infants with a respiratory index (RI) based on AaDO2 and PO2 measurements. Thirteen infants were treated with early CPAP (FIO2 = 0.3, PO2 greater than 50 torr (6.7k Pa) at a mean age of 7.1 h and 25 infants received late CPAP (FIO2 = 0.5, PO2 greater than 50 torr) at a mean age of 15.1 h. Significant differences were demonstrated between the two groups in duration of CPAP (42 versus 72 hours) peak RI (3.7 vs. 6.7), time to peak RI from start of therapy (10.0 versus 19.4 h), number of infants ventilated (0 versus 5) and number of air leaks (0 versus 3). The rate of disease worsening as measured by changes in RI/h before CPAP and after CPAP initiation was comparable in the respective treatment groups.

Carbon Dioxide↗
PubMed1981

Transcutaneous bilirubinometry. The cephalocaudal progression of dermal icterus.

The transcutaneous bilirubinometer (TcB) was used to document the cephalocaudal progression of dermal icterus in neonates. The TcB index of a specific area was compared with that of the forehead (TcB ratio). Four surface regions were identified, placed in the following sequence with respect to decreasing TcB ratio values: (1) forehead and sternum; (2) elbow, upper part of the back, and upper part of the abdomen; (3) lower part of the back and knee; and (4) palm and sole. To examine the relationship of the skin region of different serum bilirubin levels, a model was created that allowed the correlation of the TcB index with the specific region's distance from the forehead. Area differences in TcB values at lower bilirubin concentrations were less marked than at high levels. While the mechanism of this phenomenon has not been elucidated, the role of biophysical properties of the skin remains to be explored.

Abdomen↗
PubMed1980

Tolazoline and dopamine therapy in neonatal hypoxia and pulmonary vasospasm.

Severe hypoxia unresponsive to maximum ventilatory support occurs both in idiopathic respiratory distress syndrome and meconium aspiration. We recently encountered a 980 g female infant with respiratory distress syndrome and 3 300 g female infant with meconium aspiration and persistant fetal circulation whose clinical course necessitated the use of tolazoline and dopamine to reduce pulmonary and to stabilize systemic pressures. The infant with respiratory distress syndrome responded with a PaO2 increase of 2.7 kPa while the infant with persistant fetal circulation and meconium aspiration showed a 51.6 kPa rise. Combined pharmacologic therapy may have a role in improving oxygenation status in severely hypoxemic infants receiving maximum support.

Dopamine↗
PubMed1979

Discontinuation of continuous positive airways pressure in infants with respiratory distress syndrome.

Unexpected stability of arterial oxygen and carbon dioxide tensions occurred in infants recovering from respiratory distress syndrome (RDS) on the abrupt withdrawal of CPAP at 6 cmH2O pressure. 30 preterm infants (birthweights 880--3200 g gestational ages 29--38 weeks) were treated at a mean age of 10 hours and for a mean duration of 62 hours. CPAP was stopped when F1O2 requirement fell below 0.3, and stable PO2 was maintained for 4 hours. Discontinuation of CPAP at 6 cmH2O resulted in a mean change in PO2 from 66 to 64 mmHg (8.8 to 8.5 kPa) and a mean change in PCO2 from 41 to 40 mmHg (5.4 to 5.3 kPa). We conclude that this population of infants suffering from moderate RDS tolerated the abrupt withdrawal of CPAP, and that gradual reduction of pressure was unnecessary.

Carbon Dioxide↗
PubMed1978

Intermediate phototherapy in the treatment of jaundice in the premature infant.

A controlled trial of the use of intermittent phototherapy for the treatment of hyperbilirubinemia in newborn infants is reported. Periods of illumination of (1) 15 minutes light on, 15 minutes light off, (2) 15 minutes on, 30 minutes off, and (3) 15 minutes on, 60 minutes off are as effective as is continuous illumunation. A comparison with previous trials of intermittent phototherapy is made and differences in results are explained using as a model the action of light on bilirubin.

Humans↗