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Biomedical subjects

I Seri

Publications and source records attributed to I Seri.

At least 55 records · Page 3Linked to original sources

Acute oliguria in preterm infants with hyaline membrane disease: interaction of dopamine and furosemide.

Ten premature infants with hyaline membrane disease and with acute oliguria were treated with furosemide or furosemide and dopamine. Furosemide alone did not increase diuresis. Furosemide when combined with dopamine, however, caused significant increases in urine output, sodium excretion, fractional sodium excretion and creatinine clearance. These data suggest that the increase in the sodium excretion was due not only to a reduction in the tubular sodium reabsorption but also to an increase in the glomerular filtration rate. Since in premature neonates the creatinine clearance is not a very precise index of the glomerular filtration rate, the extent of contribution of the increase in the glomerular filtration rate to the enhanced sodium excretion cannot be determined. Despite the increase in the sodium excretion, the serum sodium concentration did not fall significantly. We conclude that the combined treatment with dopamine and furosemide is useful for treating furosemide-resistant, severe functional renal failure in preterm infants with hyaline membrane disease.

Anuria↗

The effect of dopamine administration on the activity of the renin-angiotensin-aldosterone system in sick preterm infants.

Nine premature infants with birth weight of 1150 to 2500 g and gestational age of 28 to 35 weeks were given dopamine in a dose of 2-4 micrograms/kg/min to treat cardiopulmonary distress. In addition to monitoring of blood gases, blood pressure, acid-base balance, urine flow and urinary sodium excretion, plasma renin activity (PRA) and plasma aldosterone concentration (PA) was also determined prior to and during dopamine therapy. The dopamine-induced increase in urine flow and urinary sodium excretion was associated with a significant increase of PRA from 18.2 +/- 5.1 ng/ml/h to 33.0 +/- 5.6 ng/ml/h (P less than 0.025), while PA and blood pressure remained unaltered by dopamine administration. It is suggested that the angiotensin II-stimulated aldosterone production is overridden by the inhibitory effect of dopamine.

Aldosterone↗

Effect of low-dose dopamine infusion on prolactin and thyrotropin secretion in preterm infants with hyaline membrane disease.

The effect of low-dose (2-4 micrograms/kg/min) and long-term (greater than or equal to 46 h) dopamine infusion on serum prolactin and thyrotropin concentrations was investigated in 8 preterm infants with hyaline membrane disease. Dopamine was administered for systemic hypotension and/or for impending renal failure. Serum prolactin decreased from 1,314.5 +/- 422.7 microU/ml to 489.9 +/- 464.1 microU/ml (p less than 0.005), while serum thyrotropin fell from 3.77 +/- 2.27 microU/ml to 1.01 +/- 0.25 microU/ml (p less than 0.025) during dopamine infusion. Our data indicate that exogenous dopamine exerts an inhibitory effect on the secretion of prolactin and thyrotropin even in the sick preterm neonate. The role of prolactin in fetal lung maturation and in regulation of the neonatal tissue water stores is discussed. The results of the present study are also useful in explaining the renal effects of long-term low-dose dopamine infusion in the sick preterm infant.

Dopamine↗

High-frequency oscillatory ventilation (HFOV) in the treatment of neonatal respiratory disturbances: case reports of two infants.

The technique of high-frequency oscillatory ventilation (HFOV) was successfully used in a preterm infant with severe hyaline membrane disease and in a term neonate presenting with intrauterine pneumonia and associated severe pneumomediastinum. None of the infants could adequately be ventilated by conventional ventilation; both of them deteriorated owing to severe hypoxaemia and hypercapnia. In the preterm infant with HMD a rapid and progressive improvement of oxygenation had been observed immediately after the beginning of HFOV, and he was successfully weaned off the ventilator after 71 hours on HFOV. His recovery was uncomplicated and definitive. In the term neonate presenting with IUP and associated severe PM, an improvement in oxygenation was detected, whereas the retention of paCO2 remained unaltered. On leaving the MAP unchanged but doubling the flow rate, paCO2 and arterial pH also normalised. No sign of PM was seen on the X-ray picture 17.5 hours after the start of HFOV. This patient was weaned off the ventilator after 29 hours on HFOV and his recovery was also uncomplicated. It is believed that recovery of the PM was secondary to the low MAP and to the higher arterial pO2 levels, and that HFOV may also have a direct role in the treatment of preexisting air leaks and perhaps also in their prevention. In our patients HFOV resulted in a definitive recovery, while no improvement had occurred on using conventional ventilation. To determine the exact mechanism of action, the clear cut fields of indications and the possible side effects of HFOV, further investigations are needed.

Carbon Dioxide↗

Cardiovascular response to dopamine in hypotensive preterm neonates with severe hyaline membrane disease.

The effect of low dose (2, 4, and 8 micrograms/kg per min) dopamine infusion on blood pressure, heart rate and renal function was studied in 18 hypotensive, preterm infants with severe hyaline membrane disease (HMD). Significant dose-related effects found during dopamine infusion were systolic and diastolic blood pressure elevation and diuretic effect, while heart rate increase occurred only with 8 micrograms/kg per min of the drug. This indicates, that in the preterm neonate, dopamine at low doses has a pronounced effect on the alpha- and dopamine-receptors, while its beta-receptor stimulating activity is minimal. We demonstrated a significantly decreased metabolic clearance rate of dopamine in preterm infants. Thus, beside the differences in the vascular receptors' maturation, the decreased metabolic clearance rate should also be taken into account when explaining the cardiovascular and renal effects of low dose dopamine infusion in these babies. Dopamine was found to be useful in normalizing low arterial blood pressure, in improving impaired peripheral circulation, and in producing a marked diuresis in hypotensive preterm neonates with severe hyaline membrane disease.

Blood Pressure↗

The use of dopamine for the prevention of the renal side effects of indomethacin in premature infants with patent ductus arteriosus.

To determine if dopamine would prevent the renal side effects of indomethacin, fifteen preterm infants were randomized into two groups: seven received indomethacin alone, and eight received indomethacin together with low dose dopamine infusion. Infants who received indomethacin together with dopamine had significantly higher UV (p less than 0.005), CNa (p less than 0.005), Cosm (p less than 0.005) and FENA (p less than 0.005) than those of infants who received indomethacin alone. There was, however, no significant difference in Ccr and FNa between the groups. These data indicate that dopamine overcomes indomethacins renal side effects of tubular origin, but it cannot prevent the renal vasoconstrictive action of vasoconstrictor hormones following the inhibition of prostaglandin synthesis by indomethacin. Considering that RBF and GFR turn to normal approximately 12 hours after the last dose of indomethacin, and that with the use of dopamine systemic blood pressure and peripheral circulation can also be normalized and to some extent myocardiac contractility improved, low doses of dopamine can be used instead of furosemide in the sick preterm infant with PDA when indomethacin therapy is indicated.

Clinical Trials as Topic↗

The clinical importance of urinary tract infections during pregnancy. III. Neonatal morbidity and mortality.

The third part of the series shows that the various forms of maternal urinary tract infections have a negative effect on the newborn. Already at birth, there are several depressed babies in need of resuscitation. The frequency of prolonged jaundice requiring treatment has been increasing. The babies are more predisposed to infections. Congenital pneumonia more often occurs. As a result, the exposure of babies to drugs and x-rays is greater and perinatal mortality is higher. The newborn are much frailer than they should be on the basis of the frequency of their prematurity. The epidemiological analysis raises the possibility of the harmful effect of intrauterine infections in bacteriuric and pyelonephritic pregnancies.

Bacterial Infections↗

[Tolazoline and dopamine in the treatment of the persistent fetal circulation syndrome].

The combined application of Tolazoline and Dopamine for the treatment of the persistent fetal circulation syndrome showed that Dopamine prevented the most common side effects of Tolazoline i.e. systemic hypotension and oliguria. The authors emphasize the importance of continuous monitoring of the systemic blood pressure in infants during this treatment.

Dopamine↗

Effects of dopamine on renal functions in premature neonates with respiratory distress syndrome.

The renal effects of dopamine have been studied in preterm infants with RDS. Dopamine has been given in doses of 0.5-2.0 microgram/kg/min as a continuous intravenous infusion in cases of peripheral circulatory disturbances. As a result, the circulation became stable and some renal parameters improved. There was a + 106% increase of urine output as well as a + 73%, + 140%, + 21% increase in Na-excretion, FeNa, creatinine clearance respectively. In accordance with the marked increase in phosphorus excretion the titratable acidity was also increased. There was a significant decrease in the renal urea excretion and free water clearance. These alterations were probably caused by an intrarenal hemodynamic redistribution. The possible mechanism of the renal changes are also discussed. The observations demonstrate the functional maturity of renal dopaminergic receptors in the preterm infants.

Dopamine↗

Developmental changes in lymphocyte surface markers.

The aim of the study was to establish normal values for TG and TM cells in neonates and small babies who are more susceptible to infections than children and adults. For the same reason, the T- and B-lymphocyte ratios were also determined. The percentage of B- and T-cells in neonates was significantly lower, while their absolute number higher, than the adult value. The percentage of TG cells was significantly higher in neonates than in the other age groups. There was a significant decrease in the ratio of TM cells as compared to adult values. Spontaneous thymidine uptake showed an inverse correlation with age, but the difference was not significant. There was a nearly identical response to PHA in the observed age groups, at least to the single dose of PHA applied.

Adolescent↗