[Show abstract][Hide abstract] ABSTRACT: Specific airway resistance (sRaw) measured by whole-body plethysmography in young children is increasingly used in research and clinical practice. The method is precise and feasible. However, there is no available method for calibration of the resistance measure, which raises concern of accuracy. Our aim was to determine the agreement of sRaw measurements in six centers and expand normative sRaw values for nonasthmatic children including these centers.
Identical hardware with different software versions was used at the six centers. Measurements followed a standard operating procedure: (1) seven healthy young children were brought to each of the six centers for sRaw measurements; and (2) 105 healthy preschool children (52 boys; mean age, 5.1 years; interquartile range, 4.3 to 6.0) were recruited locally for sRaw measurements.
(1) The sRaw of the seven-children study group was significantly lower at two centers compared with the other four centers, and one center had significantly higher sRaw than all the other centers (p < 0.05). Error in the factory settings of the software was subsequently discovered in one of the deviating centers. (2) Normative data (105 preschool children) were generated and were without significant difference between centers and independent of height, weight, age, and gender. We subsequently pooled these normative data (105 children) with our previous data from 121 healthy young children (overall mean sRaw, 1.27; SD, 0.25).
Control using biological standards revealed errors in the factory setting and highlights the need for developing methods for verification of resistance measures to assure accuracy. Normative data were subsequently generated. Importantly, other centers using such normative data should first consider proper calibration before applying reference values.
[Show abstract][Hide abstract] ABSTRACT: The efficiency of nitrofurantoin and trimethoprim prophylaxis in preventing recurrent urinary tract infections (UTI) was compared by means of actuarial percentage recurrence-free curves in a randomized, double blind study in 130 children (126 girls, 4 boys) aged 1 to 14 years (mean 7.5). The children received the antibiotics for 6 months. Nitrofurantoin proved to be the most efficient prophylactic drug in patients with abnormal urography and/or reflux (n=60) as evaluated by actuarial percentage recurrence-free analysis (p= 0.0025). However, no differences was found in patients without urinary tract abnormalities. Nitrofurantoin prophylaxis altered neither the pattern of resistance nor the bacteriological constellation, while patients receiving trimethoprim prophylaxis had 76% trimethoprim resistant bacteria during prophylaxis, compared with 8% before (p<0.0001) and 17% after (p<0.0001) prophylaxis. The percentage of recurrences due to E. coli (70-80%) was unaffected by trimethoprim prophylaxis, but the proportion due to trimethoprim resistant E. coli was significantly higher during prophylaxis (65%) than before (6%, p<0.0001) and after (11%, p<0.001). The percentage of Staphylococcus epidermidis UTI was significantly higher during trimethoprim prophylaxis (27%) than before (2%, p<0.0003). Following prophylaxis there was no difference in the actuarial percentage recurrence-free curves of the two regimens. Side effects occurred more frequently in the nitrofurantoin group (37%)than in the trimethoprim group (21%) (p=0.05). The majority of side effects in the nitrofurantoin group derived from gastrointestinal symptoms. In conclusion, nitrofurantoin is recommended as the first choice prophylactic treatment of children with recurrent UTI and urinary tract abnormalities.