Objective To evaluate the outcome of adenotonsillectomy (AT) in a cohort of children with Down syndrome (DS) and obstructive sleep apnoea (OSA).

Design Retrospective, cross-sectional study.

Setting Tertiary care centre.

Patients Children with DS and OSA, without previous upper airway (UA) surgery.

Interventions AT and full overnight polysomnography.

Main outcome results A significant improvement of the obstructive apnoea-hypopnoea index (oAHI) after AT was obtained. No differences in sleep efficiency or sleep fragmentation were found postoperatively. Almost half of the children had persistent OSA (oAHI ≥5/hour).

Results Data are presented as median (lower–upper quartile). Thirty-four children were included, median age 4.0 years (2.7–5.8), body mass index (BMI) z-score 0.81 (−0.46–1.76), and oAHI 11.4/hour (6.5–22.7). The majority presented with severe OSA (58.9%). AT was performed in 22 children, tonsillectomy in 10 and adenoidectomy in two. Postoperatively, a significant improvement of the oAHI was measured from 11.4/hour (6.5–22.7) to 3.6/hour (2.1–9.5) (p=0.001), with a parallel increase of the minimum oxygen saturation (p=0.008). Children with initially more severe OSA had significantly more improvement after UA surgery (p=0.001). Persistent OSA was found in 47.1% of the children.

Conclusions AT results in a significant improvement of OSA in children with DS without a change in sleep efficiency or sleep stage distribution. Severe OSA was associated with a larger reduction of OSA severity. Almost half of the children had persistent OSA, which was not correlated to age, gender or BMI z-score.