Material and Method: Non-snoring severe thalassemia children aged 6 to 15 years who had been followed up at King Chulalongkorn Memorial Hospital between June 2009 and March 2010 were studied. Overnight pulse oximetry and end-tidal carbon dioxide tension (PETCO2) monitoring as well as pulmonary function tests were evaluated.

Results: Fifty-eight non-snoring severe thalassemia children (aged 10.5 + 2.6 years, 43% male) were studied. 67.2% showed abnormal gas exchange during sleep. All of them had nocturnal desaturation (nadir SpO2 87 + 6.9%; range 65 to 94%). 33.3% of those who had nocturnal desaturation had associated lung function abnormality. Abnormal lung function was found in 32.8% of the present study patients. Of these, 68.4% had associated nocturnal desaturation. Age, gender, nutritional status, size of liver and spleen, history of splenectomy, hemoglobin and serum ferritin level, and lung function were not associated with abnormal gas exchange during sleep.

Conclusion: Nocturnal desaturation was demonstrated in more than a half of non-snoring severe thalassemia children. Normal lung function did not guarantee normal gas exchange during sleep. However, more than a half of those who had lung function abnormality had associated nocturnal desaturation. Evaluation of gas exchange during sleep would be merited in this group of patients.

Keywords: Thalassemia, Abnormal blood gases, Lung function