Biomedical subjects

T F Yeh

Publications and source records attributed to T F Yeh.

At least 37 records · Page 2Linked to original sources

PubMed1996

Measurement of pulmonary status and surfactant protein levels during dexamethasone treatment of neonatal respiratory distress syndrome.

BACKGROUND: Early postnatal use of dexamethasone in infants with respiratory distress syndrome (RDS) has been shown effectively to improve pulmonary status and to allow early weaning off mechanical ventilation. However, the mechanisms to explain the beneficial effects of dexamethasone in ventilatory dependent preterm infants remain unclear. METHODS: A double blind, placebo controlled study was performed to determine the change in pulmonary ventilation of premature infants with RDS as a result of dexamethasone treatment, and to evaluate the effect of dexamethasone on the levels of surfactant-associated proteins A (SP-A) and D (SP-D) in the tracheal fluid from 34 premature infants with RDS and 29 control subjects. RESULTS: Dexamethasone treatment decreased fractional inspired oxygen concentration (FIO2), arterial carbon dioxide tension (PCO2), mean airway pressure (MAP), and facilitated successful weaning from mechanical ventilation. SP-A concentrations in the tracheal aspirates were increased at days 7 and 14, and SP-D concentrations were increased during the period from days 3 to 14 in the dexamethasone treated group compared with the control group. However, albumin levels in the tracheal aspirate samples were decreased after dexamethasone treatment over the period from days 3 to 14. There was an inverse correlation between PCO2 values and SP-A concentrations. CONCLUSIONS: These results suggest that early use of dexamethasone can improve pulmonary status and also increase SP-A and SP-D levels in the tracheal fluid in premature infants with RDS.

Albumins↗

PubMed1994

Effect of aminophylline on brain stem auditory evoked potentials in preterm infants.

To determine the neurophysiological effects of aminophylline on apnoea of prematurity, the brain stem auditory evoked potentials (BAEPs) of 30 apnoeic infants and 34 age matched controls were evaluated and compared. After six days of treatment with aminophylline, the brain stem conduction time (interpeak latency of I-V) in apnoeic infants decreased compared with controls of a similar postconceptional age. The mean latencies of the peaks and interpeaks of all waves except wave I were significantly lower in the apnoeic infants after than before receiving aminophylline. No significant differences were found in the latencies of BAEPs between the apnoeic infants who responded and those who did not respond to aminophylline treatment, however. These results suggest that aminophylline may enhance conduction along central auditory pathways and stimulate the regulatory effect on the respiratory centre of the brain stem.

Aminophylline↗

PubMed1993

Alterations in theophylline metabolism during the first year of life.

Maturational changes in theophylline disposition were evaluated in 52 infants (gestational age, 24 to 40 weeks; postnatal age, 2 to 69 weeks) receiving maintenance theophylline therapy. Theophylline and metabolites were measured in serum and urine at steady state, and the influence of clinical parameters on the maturational changes was analyzed by multiple stepwise linear regression. Theophylline clearance and urine metabolite pattern reached adult values at 55 weeks' postconceptional age. Serum caffeine concentrations greater than 1 microgram/ml occurred in infants up to 50 weeks' postconceptional age. Disappearance of serum caffeine concentrations and maturation of theophylline clearance were primarily related (p < 0.001) to development of the demethylation pathway to 3-methylxanthine. Postconceptional age was the major factor (p < 0.001) explaining the interpatient variability in theophylline clearance (r2 = 0.57), serum caffeine to theophylline ratio (r2 = 0.46), and urinary excretion of theophylline (r2 = 0.51), caffeine (r2 = 0.49), 1,3-methyluric acid (r2 = 0.32), 1-methyluric acid (r2 = 0.53), and 3-methylxanthine (r2 = 0.58). Our findings indicate that postconceptional age rather than postnatal age should be used as a maturational marker during theophylline therapy in infancy.

Aging↗

PubMed1993

Congenital syphilis: clinical manifestations in premature infants.

During the 4-year period February 1989 to January 1993, 13 premature babies aged 1-21 days and with congenital syphilis were admitted to the National Cheng Kung University Hospital. Of the 13 premature infants, 8 (62%) had unusual desquamation over palms and soles. Bone changes with periosteal reaction and/or metaphyseal dystrophy were observed in 11 cases (85%). Three mothers were diagnosed as being infected during pregnancy; 2 were treated with penicillin. The clinical features of congenital syphilis in premature neonates are somewhat different from those previously reported. Bone changes, hepatosplenomegaly, respiratory distress, skin lesions, especially over the soles and palms, cerebrospinal fluid abnormalities, and jaundice were the major manifestations in our series. In premature infants with these symptoms and signs, congenital syphilis should be considered as one of the differential diagnoses. Once the diagnosis of congenital syphilis is made, adequate penicillin therapy should be given.

Female↗

PubMed1991

Assessment of gestational age in newborns by neurosonography.

Current methods for estimating gestational age using clinical parameters can be inaccurate in prematurity. A simplified ultrasonographic system, based on cerebral sulcal development, for clinically determining fetal maturation in newborns was developed and studied in 148 newborns (92 appropriate-for-gestational-age, 54 small-for-gestational-age and 2 large-for-gestational age). This ultrasonographic sulcal method correlates better with the gestational age by dates than by the Dubowitz scoring system in the neonates less than 30 weeks' gestation. There are significant correlations between gestational age assessed by dates and by sonographic sulcal age in both appropriate-for-gestational-age (R = 0.91, P less than 0.001) and small-for-gestational-age newborns (R = 0.92, P less than 0.001). Maternal hypertension during pregnancy is a significant risk factor associated with accelerated fetal cerebral maturation in 12 neonates. Although overestimate of gestational age may occur in neonates born to mothers with hypertension, cranial ultrasonography is an accurate and convenient method of estimating gestational age in neonates.

Birth Weight↗

PubMed1991

The effect of low-dose dopamine infusion on cardiopulmonary and renal status in premature newborns with respiratory distress syndrome.

To study the effects of infusion of low doses of dopamine hydrochloride on cardiopulmonary and renal status in premature newborns with respiratory distress syndrome, 49 newborns were randomly assigned to three groups: group 1 (18 patients) received no dopamine and was the control group; group 2 (16 patients) was infused with a dose of dopamine measuring 1.0 micrograms/kg of body weight per minute for 72 hours; and group 3 (15 patients) was infused with a dose of dopamine measuring 2.5 micrograms/kg of body weight per minute for 72 hours. Birth weights, gestational ages, post-natal ages, and cardiopulmonary status of all groups at the start of the study were comparable. Continuous infusion of these low doses of dopamine for 3 days after birth did not significantly improve levels of blood gases, acid-base balance, or clinical outcome. In newborns with systemic hypotension, dopamine improved cardiovascular status and caused early return of blood pressure to the normal range. Infusion of low doses of dopamine produced mild to moderate natriuresis and insignificant increases in glomerular filtration rate and urine volume.

Acid-Base Equilibrium↗

PubMed1990

Early postnatal dexamethasone therapy in premature infants with severe respiratory distress syndrome: a double-blind, controlled study.

To determine whether early (less than or equal to 12 hours) postnatal dexamethasone therapy would facilitate removal of the endotracheal tube and improve outcome in premature infants with severe respiratory distress syndrome, we conducted a double-blind, controlled study of 57 infants whose birth weights were less than 2000 gm. The placebo (n = 29) and treated (n = 28) groups were comparable in birth weight (mean +/- SD: 1273 +/- 323 vs 1318 +/- 359 gm), gestational age (30.1 +/- 2.1 vs 30.8 +/- 2.7 weeks), postnatal age (8.7 +/- 3.1 vs 8.5 +/- 3.1 hours), and pulmonary function at the start of the study. The dose of dexamethasone was 1.0 mg/kg/day for 3 days and then was progressively decreased for 12 days. Infants in the dexamethasone group had significantly higher pulmonary compliance, tidal volume, and minute ventilation, and required lower mean airway pressure for ventilation than infants in the placebo group. The endotracheal tube was successfully removed from more infants in the dexamethasone group (16/28 vs 8/29; p less than 0.025). Nineteen infants (65%) in the placebo group and 11 (39%) in the dexamethasone group (p less than 0.05) had lung injuries. Dexamethasone therapy was associated with a temporary increase in blood pressure and plasma glucose concentration and a delay in somatic growth. We conclude that early postnatal dexamethasone therapy improves pulmonary status, facilitates removal of the endotracheal tube, and minimizes lung injuries in premature infants with severe respiratory distress syndrome.

Clinical Trials as Topic↗

PubMed1989

Metabolic rate and energy balance in infants with bronchopulmonary dysplasia.

To determine energy use and growth of infants with bronchopulmonary dysplasia (BPD), we studied metabolic rate and energy balance in five infants with stage III-IV BPD (birth weight 1309 +/- 530 gm, gestational age 32 +/- 3 weeks, postnatal age 59.8 +/- 14.2 days) and in five control infants (birth weight 1540 +/- 213 gm, gestational age 33 +/- 2 weeks, postnatal age 42.0 +/- 4.2 days). Infants with BPD had significantly lower energy intake but higher energy expenditure than did control infants. Weight gain and energy cost of growth were significantly less in BPD infants than in control infants, as were urine output and output/intake ratio. We conclude that infants with BPD (1) absorbed caloric intake as well as did normal control infants, (2) had low energy intake and high energy expenditure, resulting in poor weight gain, and (3) had low energy cost of growth, suggesting an alteration in composition of tissue gain, with relatively high water content.

Body Weight↗

PubMed1989

Indomethacin therapy in premature infants with patent ductus arteriosus--determination of therapeutic plasma levels.

To determine the therapeutic range of plasma indomethacin levels for ductus closure, we evaluated the ductus response and renal side effects on two therapeutic regimens using different dosage; regimen I received 0.3 mg/kg q 24 h for a maximum of 3 doses, and regimen II received 0.1, 0.2 and 0.3 mg/kg at 24-hour intervals, for a maximum of 3 doses if needed. Infants in regimen I had significantly higher plasma indomethacin and higher ductus response rate than infants in regimen II. Urine output (U/O) was comparable between the regimens, but serum sodium was lower in regimen I than in regimen II. In both regimens, U/O and serum sodium return to normal by 72 h. The plasma indomethacin levels at 12 h after 1 dose correlated significantly with ductus response and hyponatremia. There appeared to be a minimal level of plasma indomethacin above which U/O decreased; with a plasma level greater than 170 ng/ml the majority (greater than 97%) of infants showed a decrease in U/O. While there was a 50% or greater chance that ductus would close when the plasma levels reached 600 ng/ml or more, a great proportion of infants would also develop renal side effects. Thus, a safe therapeutic range of plasma indomethacin appeared to be very narrow. However, when the dose of indomethacin is increased to optimize constrictive response, there is no significant increase in incidence and severity of renal adverse effects. In view of the transient nature of renal side effects, they should not hinder indomethacin therapy if ductus closure is indicated.

Ductus Arteriosus, Patent↗

PubMed1989

Does indomethacin affect the control of breathing in premature infants?

The effect of indomethacin on the control of breathing was simultaneously evaluated in 10 premature infants who had significant patent ductus arteriosus and received indomethacin therapy. In an attempt to maintain high plasma level in these infants of advanced postnatal age (greater than or equal to 6 weeks), indomethacin was administered intravenously at a dosage of 0.3 mg/kg, at 8-hour intervals, for a total of three doses. Following indomethacin therapy, there was a significant increase in tidal volume, minute ventilation, tidal volume/inspiratory time and in airway pressure (P0.1, Pmax) generated during airway occlusion. Seven infants required lower ventilatory rates after study. In spite of desirable plasma indomethacin level, there was no significant improvement in echo left atrium/aortic root dimension ratio, cardiovascular dysfunction score and in blood pH, PO2 and PCO2. None of the infants showed clinical evidence of ductus closure. The results of the study suggested that indomethacin may stimulate respiration and that endogenous prostaglandin may play a role in the regulation of breathing.

Ductus Arteriosus, Patent↗

PubMed1987

Indomethacin therapy in premature infants of advanced postnatal age.

Indomethacin (0.3 mg/kg every eight hours IV for three doses) was administered to eight infants whose postnatal ages were eight weeks or greater and who developed patent ductus arteriosus either in the late postnatal life or in the early neonatal period but persisted. In spite of maintenance of appropriate plasma indomethacin levels, none of the infants responded with ductus closure. The present study suggests that a distinct group of infants may exist whose ductus arteriosus is prostaglandin independent and the patency of the ductus may persist.

Age Factors↗

PubMed1987

Chest physiotherapy in preterm infants with RDS in the first 24 hours of life.

To evaluate if chest physiotherapy is beneficial to premature infants with respiratory distress syndrome (RDS) during the first 24 hours of life, 20 infants were randomly assigned to two groups; 10 infants in Group I received routine chest physiotherapy and suction, and 10 infants in Group II received suction only. The birth weight, gestational age, postnatal age, Apgar scores, blood gases, acid-base status, and ventilatory requirements prior to study were comparable between the two groups. There were no significant differences between the groups in the amount of endotracheal secretions removed, the PO2/FIO2 ratio, blood gases, and pH during the study. The incidence of patent ductus arteriosus (PDA), bronchopulmonary dysplasia (BPD), Grade I and II intraventricular hemorrhage (IVH), and mortality was comparable. However, five of 10 Group I and zero of 10 Group II infants developed Grade III or IV IVH (P less than 0.05).

Blood Gas Monitoring, Transcutaneous↗

PubMed1986

Green vomiting in the first 72 hours in normal infants.

From June 1980 to September 1984, forty-five newborns (weight greater than or equal to 2000 g), initially presumed normal, were seen with bilious vomiting in the first 72 hours and were prospectively followed up. Nine (20%) required surgical intervention, five (11%) had nonsurgical obstruction such as meconium plug or left microcolon, and the remaining 31 (69%) had idiopathic bilious vomiting. Infants with idiopathic bilious vomiting had a benign transient course and resumed feedings by 1 week of age; 30 of the 31 had normal or nonspecific findings on initial plain abdominal roentgenogram. Specific findings on the initial plain abdominal roentgenogram were noted in five infants, and four (80%) of these had a lesion requiring surgical intervention; 56% (5/9) of neonates with surgical lesions had normal or nonspecific findings on the plain abdominal roentgenograms. None developed bowel ischemia or midgut infarction secondary to a volvulus as they were identified by contrast studies shortly after the initial episode of bilious vomiting. Although the majority of "normal" neonates with bilious vomiting do not have a surgical lesion, this study indicates that 56% of surgical cases will be missed if contrast studies are not done.

Age Factors↗

PubMed1986

Indomethacin therapy in premature infants with patent ductus arteriosus and oliguria.

Simultaneous administration of one dose of indomethacin (0.3 mg/kg, i.v.) and furosemide (1 mg/kg, i.v.) was given to 8 consecutive premature infants who had patent ductus arteriosus (PDA), and oliguria because of prerenal failure. Four infants responded with ductus closure and 2 infants showed improvement in echocardiogram and clinical distress. There was a significant increase in U/O, GFR, FENa and FECl following drug administration. This study suggests that simultaneous administration of indomethacin and furosemide can be safely used in infants with PDA and oliguria.

Anuria↗

PubMed1986

Indomethacin therapy in infants with advanced postnatal age and patent ductus arteriosus.

A trial of intravenous indomethacin therapy was performed on 11 premature infants whose postnatal age was 8 weeks or more (mean 65.3 days). In an attempt to maintain the desired plasma level, indomethacin was given at a dosage of 0.3 mg/kg, at 8-hour intervals (total dose 0.9 mg/kg) for a total of 3 doses. In spite of desirable plasma indomethacin levels (which ranged from 280-870 ng/ml) and area under the curve (24.1 micrograms/hr/ml), calculated from time 0 to 24 hrs after the initial dose, none of the infants responded to indomethacin with ductus closure. There were a transient significant decrease in urine output, creatinine clearance, and fractional excretion of sodium. The present study confirms the clinical impression that Indomethacin is ineffective for the closure of ductus arteriosus in infants with advanced postnatal age.

Cardiovascular System↗

PubMed1985

Pulmonary and renal responses to furosemide in infants with stage III-IV bronchopulmonary dysplasia.

Pulmonary and renal responses to furosemide were evaluated in ten infants with stage III-IV bronchopulmonary dysplasia. Furosemide was given intravenously for two doses, 1 and 2 mg/kg, at approximately 24-hour intervals. The following indices were evaluated in series before and after entry into study: clinical respiratory distress syndrome score; blood pH; partial pressure of arterial carbon dioxide; alveolar-arterial oxygen gradient; urine output; glomerular filtration rate; fractional excretion of filtered sodium, chloride, potassium, and calcium; osmolar clearance; water clearance; and concentrations of serum electrolytes and calcium. A significant decrease in the respiratory distress syndrome score and in the partial pressure of arterial carbon dioxide was seen only transiently at two hours following each dose. There was no significant improvement in the alveolar-arterial oxygen gradient during the study. Furosemide induced diuresis and urinary excretion of sodium, chloride, potassium, and calcium. A significant decrease in serum chloride and potassium concentrations was seen at 48 hours after entry into study; serum sodium and calcium concentrations remained unchanged. This study has demonstrated that furosemide administration has only a short-term effect in the lung but has a potential for long-term complication on electrolytes and calcium balance in infants with well-established stage III-IV bronchopulmonary dysplasia.

Bronchopulmonary Dysplasia↗

PubMed1985

Prevention of gastric inflation during mask ventilation in newborn infants.

Ten premature infants who had recovered from the respiratory distress syndrome were subjected to cricoid compression during mask ventilation. Each infant was ventilated with an AMBU face mask for 3 min with the nasogastric (NG) tube, without the NG tube, and without the NG tube but applying cricoid pressure during ventilation. The results of the study indicated that, similar to insertion of an NG tube, cricoid compression can prevent gastric inflation during mask ventilation.

Cricoid Cartilage↗

PubMed1985

Renal response to frusemide in preterm infants with respiratory distress syndrome during the first three postnatal days.

The renal effects of frusemide treatment in infants with respiratory distress syndrome shortly after birth and during the first three postnatal days were evaluated. Eighty five infants were randomly assigned to two groups. Forty two received three doses of intravenous frusemide (1 mg/kg) starting at age, mean (SD) 7.5 (4.1) hours and given at approximately 24 hour intervals. Forty three control infants were treated similarly but were not given frusemide. The groups were comparable in birthweight, gestational age, and Apgar score and in pulmonary status, blood gases, serum electrolytes, and postnatal age. Infants who received frusemide had significantly higher fractional excretion of sodium and chloride at 12 to 24, 24 to 48, and 48 to 72 hours, and higher calcium excretion at 24 to 48 and 48 to 72 hours after entry into the study than control infants. The study group had a significantly higher urine output and greater weight loss than the control group at 48 to 72 hours after entry into the study. There was no significant difference between groups in serum sodium, potassium, and calcium and in fractional excretion of potassium and the glomerular filtration rate. Infants with an Apgar score of more than 3 had higher urine output and had a better diuretic response to frusemide than those with a lower score. The results suggest that perinatal hypoxia may play an important role in renal function and in diuretic response to frusemide shortly after birth and early in the postnatal life of infants with respiratory distress syndrome.

Apgar Score↗