Cut-off values for positive bronchodilator response in healthy Thai preschool children using forced oscillation technique.

BACKGROUND: Forced oscillation technique (FOT) requires minimal patient cooperation and is particularly useful in young children. Bronchodilator test is a valuable tool for wheezy and asthmatic patients. The cut-off value for bronchodilator response by FOT in healthy Thai children has not been reported. OBJECTIVE: To determine the cut-off values for positive bronchodilator response in healthy Thai preschool children using pseudorandom FOT. METHODS: FOT was used to measure respiratory function at baseline and after 400 mcg MDI salbutamol in healthy Thai children aged 3-6 years. Respiratory resistance (Rrs) and reactance (Xrs) at 6, 8, and 10 Hz were collected. Pre- and post-bronchodilator tests were compared using paired t-test. Absolute and percent changes after bronchodilator were calculated and their cut-off values were defined as mean ± 1.96 SD. Correlation between each of those and baseline data was analyzed using Pearson's correlation coefficient. RESULTS: Of the 150 enrolled children, FOT measurement at baseline and after bronchodilator was successfully completed in 111 children (51 boys). The mean ± standard deviation age, height, and arm span was 5.2 ± 1.1 years, 109.3 ± 8.7 cm, and 107.2 ± 9.1 cm, respectively. No correlation was observed between any absolute or percent changes in bronchodilator response and gender, age, height, or arm span. The cut-off values established for bronchodilator response by percent change were, as follows: Rrs6: -23%, Rrs8: -20%, Rrs10: -20%, Xrs6: 36%, Xrs8: 60%, and Xrs10: 43%. CONCLUSIONS: The cut-off values identified in this study will be useful for evaluating bronchodilator response by FOT in wheezy and asthmatic young children.

Long-term outcome in pediatric renal tumor survivors: experience of a single center.

Medical records of 30 children with renal tumor diagnosed at Siriraj Hospital during 1996 to 2007 were reviewed. Mean age at diagnosis was 36 months; male to female ratio was 1.7:1. Clinical manifestations included abdominal mass (96.7%), hypertension (40.0%), abdominal pain (36.7%), hematuria (26.7%), postrenal obstruction (16.7%), and proteinuria (13.3%). Eight patients had Denys-Drash malformations, WAGR, Dandy-Walker malformation, or genitourinary anomalies. Twenty-seven patients (90%) had Wilms tumor. Sixteen patients were stage 3 or more at diagnosis. Rhabdoid tumor was found in 3 patients. All patients received chemotherapy, 13 patients also received radiation therapy. Acute complications included febrile neutropenia (44.4%), hypokalemia (37.0%), hyponatremia (29.6%), Fanconi syndrome (11.1%), urinary tract Infection (10.0%), and acute renal failure (7.4%). Mean follow-up time was 57.2 months. Ten patients died from progressive disease. Five-year patient survival was 69.7%. Two patients had chronic kidney disease. One of these had Denys-Drash malformations. Both patients received ifosfamide-carboplatin-etoposide protocol and abdominal radiation. Antihypertensive medications were needed in 9 patients for a mean duration of 164 days. None had persistent proteinuria or hematuria. No difference was found among mean estimated glomerular filtration rate at diagnosis, 1 year after treatment, and at last follow-up. Long-term follow-up, especially renal function, is recommended.