Research on sleep disordered breathing in children

Abstract

Obstructive sleep apnea (OSA) is the most common sleep disordered breathing in children. Research publications on childhood OSA in Thailand have been started since 1997. At Ramathibodi Hospital we found that of 39 children undergoing polysomnography during 1994-1997, 14 (36%) were found to have severe OSA (OA > 10/hour of total sleep time and SpO2 < 75%). In the south part of Thailand, Anuntaseree et al. have conducted epidemiological studies and showed that in children aged 6-13 years, the incidence of habitual snoring and OSA were 8.5% and 0.7% respectively. In 2001, Eiamudomkal et al. reported 11 out of 24 children with OSA having pulmonary hypertension and nadir SpO2 < 65% was shown to be the most important predictive factor. Khositseth et al. later showed that QT dispersion presented on ECG was significantly increased in childhood OSA, particularly in obese children. Thai children more likely have late diagnosis and thus more complications related with OSA. The main reasons are due to shortage of pediatric sleep laboratory and sleep specialists. Therefore alternative tests should be sought out. In 2000, we conducted a parent questionnaire research and found that it is not useful because of low specificity and sensitivity. In 2003, we used video symptoms questionnaire in which the parents compared their own child’s nighttime symptoms with our video. The results showed that the specificity was closed to 100% but the sensitivity was too low. Even if we modified the report of symptoms to visual analog scale, the results still was inconclusive. In 2004, overnight pulse oximetry was used to record SpO2 every 2 seconds and then create a dot graph in which Y axis was SpO2 values and X axis was time when the patient was sleeping. We showed that if there were more than 3 clusters of desaturation, the positive predictive value and specificity were closed to 100% which confirmed the findings of Canadian investigators. Therefore pulse oximetry has been preferably used as a screening test where PSG is not available. Nongnaphat Chirawutthinan, our fellow, recently conducted a nice study showing that video clips recorded by smart phones at home were a promising method to screen childhood OSA. If paradoxical chest movement, continuous snoring and subcostal retractions were detected on a 5- minute clip, that patient most likely had moderate to severe OSA and needed early interventions. It is hoped that in the future when OSA attracts more public attention, the patients will be diagnosed and managed earlier and more appropriately.