RT Journal Article SR Electronic T1 First night effect for polysomnographic data in children and adolescents with suspected sleep disordered breathing JF Archives of Disease in Childhood JO Arch Dis Child FD BMJ Publishing Group Ltd and Royal College of Paediatrics and Child Health SP 233 OP 237 DO 10.1136/adc.2005.085365 VO 91 IS 3 A1 S L Verhulst A1 N Schrauwen A1 W A De Backer A1 K N Desager YR 2006 UL http://adc.bmj.com/content/91/3/233.abstract AB Aims: To assess the presence of a first night effect (FNE) in children and adolescents and to examine if a single night polysomnography (PSG) is sufficient for diagnosing obstructive sleep apnoea syndrome (OSAS). Methods: Prospective case study of 70 patients (group 1: 2–6 years, n = 22; group 2: 7–12 years, n = 32; group 3: 13–17 years, n = 16) referred for OSAS. Diagnostic criteria for OSAS: one or more of the following: (1) obstructive apnoea index (OAI) ⩾1; (2) obstructive apnoea hypopnoea index (oAHI) ⩾2; (3) SaO2 ⩽89% in association with obstruction. Results: In all age groups, but mainly in the oldest children, REMS increased during the second night, mainly at the expense of stage 2 sleep. The first night PSG correctly identified OSAS in 86%, 91%, and 100% of the children for groups 1, 2, and 3 respectively. This represents 9% false negatives for OSAS when only the first night PSG was used. All cases missed had mild OSAS, except for one with oAHI >5 on night 2. There were also seven patients with OSAS on night 1 but with a normal PSG on night 2: all had oAHI <5. Conclusion: There is a FNE in children and adolescents. A single night PSG is sufficient for diagnosing OSAS, but in cases with a suggestive history and examination and with a negative first night, a second night study might be advisable.