Biomedical subjects

U Broberger

Publications and source records attributed to U Broberger.

35 records · Page 2Linked to original sources

PubMed1987

Pharmacokinetics of free and total flucloxacillin in newborn infants.

Flucloxacillin 50 mg/kg b.w. was administered intravenously (in combination with ampicillin/gentamicin) and orally (with amoxicillin) to 9 newborn infants (gestational age 33-41 weeks) to treat bacterial infections. The concentrations of flucloxacillin in plasma and urine after i.v. injection were analysed according to an open two-compartment model, and the plasma protein binding of flucloxacillin and its distribution to blood cells and plasma water in whole blood were determined. Considerable differences were found from values reported in adults. The terminal half-life averaged 4 h 38 min and was significantly correlated with gestational age. Plasma clearance was low (0.744 ml X min-1 X kg-1), due to the small renal clearance (0.182 ml X min-1 X kg-1), whilst non-renal clearance (0.563 ml X min-1 X kg-1) was approximately the same as in adults. The mean apparent volume of distribution of total drug (Vz) was 0.280 l/kg. The corresponding volume of distribution of unbound drug (Vu1 + Vu2) was 1.74 l/kg, which indicates considerable extravascular drug binding. The plasma protein binding of flucloxacillin (mean 86.3%) was significantly correlated with gestational age and the bilirubin/albumin concentration ratio. Bioavailability after oral administration, when corrected for changes in terminal half-life, was 47.7%, which is only slightly lower than that reported in adults. Since the plasma concentrations after both i.v. and oral administration were well above the MIC-values generally reported for Staphylococcus aureus, and since few side-effects were observed, intravenous injection or, in selected cases, orl administration of flucloxacillin appears to be a reliable therapy for the treatment of infections due to sensitive strains of S. aureus in premature newborn infants.

Administration, Oral↗

PubMed1987

Arterial blood pressure in the very low birthweight neonate. Evaluation of an automatic oscillometric technique.

The noninvasive oscillometric technique of arterial blood pressure determination was evaluated in fifteen very low birth weight neonates (less than 1,400 g). Measurement of invasive umbilical artery catheter pressure was used as a reference standard. By using a cuff width to arm circumference ratio of 0.33-0.42, mean blood pressure was overestimated by 6.2 (7.2) mmHg (mean and 1 SD), p less than 0.001. More accurate mean blood pressure measurements were recorded with a cuff width to arm circumference ratio of 0.44-0.55. Measurements of systolic and diastolic blood pressure showed similar results.

Blood Pressure↗

PubMed1986

Ketotifen in pollen-induced asthma: a double blind placebo-controlled study.

Twenty-nine children with an average age of 10.5 years were studied with respect to the protective effect of ketotifen on pollen-induced bronchial asthma. All of them were sensitive to deciduous tree pollen, the diagnosis being verified by bronchial challenge. The children were stratified in matched pairs and randomly allocated to two treatment groups, placebo or ketotifen 1 mg twice daily. The study was double-blind and was performed during the whole of the deciduous tree pollen season. Daily pollen counts were made, allergic symptoms were noted, additional medication was given and the expiratory pulmonary flow was recorded. During the birch pollen peak the ketotifen group showed significantly fewer, and less severe asthma and rhinoconjunctivitis than the placebo group. The anti-asthmatic medication was also used significantly less than in the placebo group. Ketotifen appeared to have good protective properties in the treatment of pollen-induced asthma and rhinoconjunctivitis.

Adolescent↗

PubMed1986

Clinical and immunological effects of oral immunotherapy with a standardized birch pollen extract.

Oral immunotherapy (IT) was evaluated in a pilot study in two centres in children aged 8-15 years with allergic rhinoconjunctivitis. High doses (up to 20 X 10(6) BU monthly) of a defined freeze-dried birch pollen extract administered in enteric-coated gelatine capsules were given either daily for seven consecutive days every month or once weekly. Symptom scores, as assessed by sneezing, dripping and blockage of the nose, and redness, itching and swelling of the eyes, were significantly lower in treated patients compared to untreated, or placebo treated controls after 3 to 5 months of therapy. In all the 16 treated, but only in three of eight untreated patients, the scores were lower during the pollen season 1982 than during the pollen season preceding the treatment period, despite comparable pollen counts during the two seasons. One year after beginning treatment the reactivity in conjunctival provocation tests was decreased about 10-fold (P less than 0.001) in the patients receiving more than 2 X 10(5) BU monthly compared to about two-fold in patients receiving lower doses, or placebo. Increased levels of IgE antibodies directed against birch pollen were recorded in the serum and saliva of most patients after 3-4 months of active IT. In contrast, IgG antibody responses were poor in most of the patients. Side effects, particularly from the gastrointestinal tract, appeared in all treated children. In one of them a systemic reaction occurred during IT. The study indicates that properly performed oral IT with a potent birch allergen extract in enteric-coated capsules may be effective.

Administration, Oral↗

PubMed1986

A simplified model for adjustment of gentamicin dosage in newborn infants.

In a retrospective study of 72 neonates during treatment with gentamicin, poor correlation was found between dosage based on body weight and gentamicin serum concentrations. Calculation of adequate gentamicin dosage regimen during steady-state based on individual pharmacokinetic parameters according to Gibaldi & Perrier was then studied in 35 newborn infants during therapy. Predictions were based on gentamicin serum concentrations taken prior to and 1, 3, and 5 hours after the first (n = 8) or second (n = 12) dose (group A), or only prior to and one hour after dose (group B, n = 15). Half-life (t1/2), apparent volume of distribution (Vd), body clearance (Clbody) and elimination rate constant (beta) were not significantly different when calculated after the first or second dose or during steady-state. The correlation between predicted and observed gentamicin concentration was high in both groups (p less than 0.005) and the slopes congruent with unity. After dose or interval correction, 73% of the observed predose concentrations (mean 2.0 micrograms/ml) were within 1 microgram/ml of predicted values. One hour after dose the predicted (mean 5.7 micrograms/ml) and observed (mean 6.2 micrograms/ml) values were not significantly different. Higher precision was noted when the predictions were based on 4 samples (group A) compared to 2 (group B). Since the calculations may be performed by a simple desk calculator rapid advice may be given to the clinical staff on adequate gentamicin dosage even in small severely ill preterm infants.

Bacterial Infections↗

PubMed1985

Rotavirus infections in newborns: an epidemiological and clinical study.

An outbreak of rotavirus infections among newborns at Karolinska Hospital, Stockholm, which has been going on for greater than 2 years has been followed with clinical and epidemiological investigations. About one third of the babies born in the hospital were infected at the age of 3 days. The clinical symptoms were mild, 8.8% of the rotavirus positive babies had loose stools compared to 1.9% of those who did not excrete the virus. An epidemiological survey in the neonatal intensive care unit suggested that rotavirus was introduced into the unit by babies admitted from the obstetric wards. The main reservoir of rotavirus was the babies and rotavirus was not found among staff or mothers. In the beginning hygienic measures seemed to be effective but after some weeks the colonization rate again increased. Electropherotyping of samples collected during different periods showed that one single rotavirus electropherotype belonging to the subgroup 1 of human rotavirus was found throughout the outbreak.

Diarrhea↗

PubMed1984

Sympatho-adrenal activity and metabolic adjustment during the first 12 hours after birth in infants of diabetic mothers.

Plasma adrenaline and noradrenaline concentrations at birth were the same in infants of diabetic mothers and controls after both vaginal and abdominal delivery. The infants delivered vaginally had significantly higher noradrenaline concentrations than those delivered by caesarean section. During the first 12 postnatal hours, the concentration of noradrenaline decreased to levels similar to those found in newborn infants with minor respiratory problems. No hypoglycemic values were recorded in infants of diabetic mothers at birth nor during the first twelve hours after birth. The C-peptide concentrations at birth were significantly lower in infants of diabetic mothers delivered vaginally as compared to those delivered by caesarean section. The FFA concentrations increased after birth possibly as a result of the lipolytic action of catecholamines released during labour and delivery. We have not been able to confirm the increased sympatho-adrenal activity previously reported in infants of diabetic mothers. We suggest that the difference is due to better metabolic control in the diabetic mothers during pregnancy and delivery in this study.

Adaptation, Physiological↗

PubMed1983

Glomerular tubular balance in preterm and fullterm infants.

The development of glomerular and tubular function was studied in preterm and fullterm infants of varying gestational and postnatal age. The results indicate that glomerular functional development precedes tubular functional development until the 34th postmenstrual week. After the 34th week the tubular transport capacity seems to be more vulnerable than the glomerular filtration rate in states of disease. The release of a postulated renal vasoconstriction could account for the rapid changes in renal function after birth. The purpose of such a vasoconstriction could be to protect the tubules from an overload.

Absorption↗

PubMed1980

Ventilatory studies in two older infants with prolonged apnea.

Two infants, both born before term, were found apneic, cyanotic and limp at home when they were 9 weeks and 2 weeks old, respectively. Their respiration was monitored in the hospital and found to be remarkably periodic during sleep, and was in one case accompanied by pronounced bradycardia. The periodic breathing and apnea seemed to be caused by a decreased oxygen tension which can induce an instability of the central respiratory control mechanisms.

Apnea↗

PubMed1979

Renal function in infants with hyperbilirubinemia.

A total of 45 infants were studied on the fourth or fifth day of life: 13 term and 10 pre-term infants with serum bilirubin levels ranging between 257 and 390 mumol/l were compared with 12 term and 10 pre-term infants with serum bilirubin levels below 195 mumol/l. The groups did not differ with regard to mean gestational age or mean post-natal age. GFR and CPAH were determined with the single injection clearance method and ability to excrete Na+ was determined following an oral loading of sodium chloride. GFR was lower in infants with hyperbilirubinemia and correlated negatively to the highest recorded serum bilirubin value. CPAH was similar in hyperbilirubinemic infants and controls. The urinary sodium excretion was significantly higher in infants with hyperbilirubinemia.

Age Factors↗

PubMed1979

Beta-2-microglobulin, an indicator of renal tubular maturation and dysfunction in the newborn.

The urinary excretion and proximal tubular reabsorption of beta-2-microglobulin was studied in 17 healthy newborn infants in relation to gestational and post-natal age. The effect of IRDS and non-conjugated hyperbilirubinemia on the tubular reabsorption of the protein was evaluated in 10 IRDS infants and 14 infants with non-conjugated hyperbilirubinemia. The urinary excretion of beta-2-microglobulin was determined under standardized conditions. When GFR was determined, the single injection clearance method was used. The filtered load of beta-2-microglobulin was found to increase with increasing gestational age. This was due to a rise in plasma beta-2-microglobulin concentration as well as to a rise in the GFR. Although the smallest filtered load was recorded in infants with a mean GA of 32.4 weeks, these infants had a lower fractional reabsorption of the protein (88%) than infants with a mean GA of 35.0 weeks or more (98%). In infants with a GA of 35 weeks or more a glomerulo-tubular balance for beta-2-microglobulin apparently was established. In these infants the filtered load of beta-2-microglobulin increased rapidly during the first days of life. This was paralleled by an increase in the reabsorptive capacity for the protein. In infants with IRDS and in infants with non-conjugated hyperbilirubinemia the fractional reabsorption of beta-2-microglobulin was lower than in control infants of a corresponding gestational and postnatal age. This indicates, that in the neonatal period, the proximal tubular transporting capacity is more vulnerable than the glomerular filtration rate in states of hypoxia and hyperbilirubinemia.

Age Factors↗

PubMed1978

Renal function in idiopathic respiratory distress syndrome.

Renal function was studied in 11 pre-term infants with idiopathic respiratory distress syndrome (IRDS) grade 1 according to Prod'hom's criteria. As a reference 16 healthy pre-term infants were studied. The groups did not differ with regard to mean gestational age (GA) and mean postnatal age (PNA). The studies were prefomred twice, first at a PNA of 33--37 hours and then at 132--148 hours. GFR and CPAH were determined with the single injection technique and the ability to excrete Na+ was determined following an oral Na+ load. GFR was higher in IRDS infants at the first investigation and slightly lower in IRDS infants at the second investigation. The GFR correlated to the lowest recorded PaO2 (r=0.45) in IRDS infants. CPAH was similar in IRDS and controls at the first, and lower in IRDS infants at the second investigation. The urinary Na+ excretion was significantly higher in IRDS infants. Treatment with digitalis was in part responsible for the high urinary Na+ excretion. The IRDS infants had a higher Na+ and glucose intake than the control infants. It is suggested that this higher intake is in part responsible for the relatively high GFR and urinary Na+ excretion in IRDS infants.

Blood Pressure↗

PubMed1975

Acid-base and electrolyte balance in infants of diabetic mothers. Vaginal delivery versus caesarean section.

The acid-base and electrolyte balance of 30 women studied at delivery and in their infants during the first 48 h. 18 women were diabetics, 10 of these were delivered vaginally (DMvag) and 8 by elective caesarean section (DMcs). 12 healthy women were vaginally delivered (HMvag). The infants of diabetic mothers (IDM) received active infusion therapy. At birth the DMvag and their infants (IDMvag) had a more pronounced metabolic acidosis than the DMcs and their babies (IDMcs). The largest metabolic acidosis occurred, however, in the group of HMvag and their infants (IHMvag). After birth no significant differences were obtained in the acid-base and electrolyte balance between IDMvag and IDMcs. The plasma potassium level remained lower in IDM than in IHM. The study stress the importance of adequate management of diabetes in pregnancy in combination with active intravenous therapy during delivery and to the infant in the immediate neonatal period. The slightly larger metabolic acidosis seen in combination with vaginal delivery suggests that this mode of delivery should not be attempted uncritically in diabetic women.

Acid-Base Equilibrium↗

PubMed1973