Aim
This is the first study to evaluate compliance with the 2003 Swedish national guidelines for prophylactic treatment of respiratory syncytial virus (RSV) in children with congenital heart disease ...(CHD). We estimated the relative risk (RR) of children with CHD being hospitalised with a RSV infection, studied the extent to which RSV prophylactic treatment with palivizumab corresponded to the guidelines and determined the morbidity of children with CHD who developed RSV infection despite prophylaxis.
Methods
This national observational study comprised prospectively registered data on 219 children with CHD treated with palivizumab, medical records on RSV cases and information on hospitalisation rates of children with CHD and RSV infection.
Results
The calculated RR of children with CHD being hospitalised with RSV infection was 2.06 (95% CI 1.6–2.6; p < 0.0001) compared with children without CHD. Approximately half of the patients (49%) born before the RSV season and 25% born during the RSV season did not start treatment as recommended by the guidelines.
Conclusion
Having CHD increased the rate and estimated RR of children being hospitalised with RSV infection. The guidelines were not followed for about half of the children born before a RSV season and a quarter of the children born during a RSV season and need updating.
Purpose
Numerous studies have investigated causes of warfarin dose variability in adults, whereas studies in children are limited both in numbers and size. Mechanism-based population modelling ...provides an opportunity to condense and propagate prior knowledge from one population to another. The main objectives with this study were to evaluate the predictive performance of a theoretically bridged adult warfarin model in children, and to compare accuracy in dose prediction relative to published warfarin algorithms for children.
Method
An adult population pharmacokinetic/pharmacodynamic (PK/PD) model for warfarin, with
CYP2C9
and
VKORC1
genotype, age and target international normalized ratio (INR) as dose predictors, was bridged to children using allometric scaling methods. Its predictive properties were evaluated in an external data set of children 0–18 years old, including comparison of dose prediction accuracy with three pharmacogenetics-based algorithms for children.
Results
Overall, the bridged model predicted INR response well in 64 warfarin-treated Swedish children (median age 4.3 years), but with a tendency to overpredict INR in children ≤2 years old. The bridged model predicted 20 of 49 children (41 %) within ± 20 % of actual maintenance dose (median age 7.2 years). In comparison, the published dosing algorithms predicted 33–41 % of the children within ±20 % of actual dose. Dose optimization with the bridged model based on up to three individual INR observations increased the proportion within ±20 % of actual dose to 70 %.
Conclusion
A mechanism-based population model developed on adult data provides a promising first step towards more individualized warfarin therapy in children.
Aim: To study the effects of postnatal exposure to nicotine on the regulation of heart rate and blood pressure in infants.
Subjects and Methods: Thirty‐eight mother–infant pairs were studied. Twenty ...nonsmoking and 18 smoking (2–20 cigarettes per day) mothers were included. All infants were healthy, exclusively breastfed and their postnatal age was 6 weeks. During a home visit infant's urine and mothers' milk were sampled and concentrations of nicotine and cotinine were analyzed. Infants' electrocardiogram (ECG) were recorded, sleep state documented and blood pressure during sleep was measured. Heart rate variability (HRV) was calculated with spectral analysis of R–R intervals.
Results: The smoking mothers exposed their infants to nicotine in milk with a median nicotine concentration of 47 (8–192) μg/L. Analysis of infants' urine showed that the nonsmoking group had 0.8 (0–5.2) and the smoke group 60 (17–139) μg cotinine/L (p < 0.01). The frequency domain low‐to‐high frequency (LF/HF) ratio, was correlated to milk nicotine concentrations in the milk sample, from smoking mothers. HRV decreased, with increasing milk nicotine, ingested by the boys (r =−0.74, p = 0.02) but not the girls (r =−0.13, p = 0.76). The differences of mean arterial pressure between sleep states in the infants, were significantly lower in the smoke group 5.8(6.8) compared to the nonsmoke group 11.5(7.2) mmHg (p = 0.03).
Conclusions: Postnatal exposure to nicotine influences autonomic cardiovascular control in infants.
Left ventricular output, left ventricular stroke volume, and systemic vascular resistance were measured noninvasively in 16 healthy term infants at 6 predefined time intervals from less than 15 ...minutes to 72 hours after birth. The blood flow velocity in the ascending aorta was measured by range-gated Doppler technique and multiplied by the cross-sectional area, measured by 2-dimensional and M-mode echocardiography to yield left ventricular output. Stroke volume was calculated by dividing left ventricular output by heart rate. Mean arterial blood pressure was measured by oscillometric technique and used for calculation of systemic vascular resistance. A poor association between heart rate and left ventricular output was found, whereas there was a very close relationship between stroke volume and left ventricular output. There was also a reciprocal relationship between systemic vascular resistance and stroke volume. This suggests that stroke volume and not heart rate is the main determinant of neonatal left ventricular output and that the low postnatal afterload might strengthen this relationship.
Patients with atrial correction of transposition of the great arteries (TGA) may develop right ventricular (RV) failure with time. A reliable non-invasive method for assessment of ventricular ...function is therefore needed. To evaluate the accuracy of echocardiography in assessment of ventricular volumes and function in these patients we compared echocardiography with magnetic resonance imaging (MRI) in 10 patients late after the Mustard and Senning procedures.
Prospective echocardiography and MRI examinations were performed on the same day. Two different echocardiography technicians examined all patients. All echocardiography and MRI examinations were performed at the university hospital outpatient clinic and MRI department respectively. Ten patients, age 14.0+/-2.9 years, who had been operated on with atrial correction of TGA at 8 (2-60) months of age (median and range) were examined. Echocardiography RV and left ventricular (LV) end-systolic volumes (ESVs), end-diastolic volumes (EDVs), stroke volumes (SVs) and ejection fractions (EFs) were calculated, using the modified Simpson method, and compared with the same measurements obtained from MRI.
For RV function there was good agreement between echocardiography- and MRI-derived measurements. Both echocardiography and MRI revealed reduced RV function with EFs of 42.6+/-9.1% and 46.4+/-7.2% respectively. For RV volumes there were no significant differences between echocardiography and MRI. LV function was significantly overestimated by echocardiography (EF with echocardiography = 72.7+/-4.4% vs. MRI = 50.5+/-7.6%) while all LV volumes were greatly underestimated. Echocardiography measurements of volumes in repeated examinations by different technicians showed large variations, 13-50%, for different variables in individual patients.
Echocardiography can provide clinically important information concerning RV function in follow-up of patients late after atrial correction of TGA. It has limited value in assessment of LV function in these patients. Volume measurements by echocardiography are, however, highly user-dependent and interobserver variation is high. MRI may accordingly serve as an important reference method in individual patients.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, UILJ, UKNU, UL, UM, UPUK
A range-gated Doppler technique was used to assess intracranial arterial blood flow velocity changes in 20 healthy term infants during the first 3 days after birth. Systolic, diastolic, and mean flow ...velocity decreased during the first 30 min after birth whereas arterial pressure and heart rate did not change. Mean flow velocity did not change from 30 min to 72 h of life, although systolic and diastolic flow velocity changed in opposite directions. Systolic flow velocity increased to 2 h of age and thereafter decreased. Diastolic flow velocity decreased to a minimum value at 2 h and thereafter increased to 24 h of age. These flow velocity changes suggest an initial decrease in cerebral perfusion, followed by a constant cerebral blood flow during normal circulatory transition after birth.
The survival for patients with atrioventricular septal defect has improved markedly over the last decades and, during the same period, the survival of children with Down's syndrome has also ...increased. The aim of our study was to investigate long-term survival in patients having atrioventricular septal defect with common valvar orifice, but without associated significant congenital heart defects, in the setting of Down's syndrome, comparing the findings to those in chromosomally normal children with the same malformation.
In a population-based retrospective study, we scrutinised the medical records from 801 liveborn children with atrioventricular septal defect born in Sweden during the period 1973 through 1997. Data on gender, presence or absence of Down's syndrome, associated congenital heart defects, date of birth, operation and death were recorded and followed up until 2001. An isolated atrioventricular septal defect with common atrioventricular valvar orifice was present in 502 children, of whom 86% had Down's syndrome. We found a significant reduc tion over time in age at operation, and in postoperative mortality at 30 days, from 28 to 1%. Using a multiple logistic regression model, we found no significant differences in mortality between genders, nor between those with or without Down's syndrome. Early corrective surgery could not be identified as a significant independent factor for survival. The 5-year postoperative survival in patients with Down's syndrome increased from 65% over the period from 1973 through 1977, to about 90% in the period 1993 through 1997, and the same trend was observed in chromosomally normal patients.
Survival in uncomplicated atrioventricular septal defect with common atrioventricular valvar orifice has greatly increased, and surgical correction is now equally successful in patients with Down's syndrome and chromosomally normal patients, and for both genders. Death in connection with surgery is no longer the major threat, and focus must now be on long-term follow-up.
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