Overnight oximetry as a screening tool for moderate to severe obstructive sleep apnoea in South African children.

BACKGROUND: Obstructive sleep apnoea (OSA) is common in children yet often overlooked, as symptom-based screening is unreliable. Polysomnography is regarded as the gold standard for the diagnosis of OSA, but is not widely available in South Africa (SA). Overnight oximetry is a validated screening tool for OSA.

OBJECTIVES: To describe the impact and utility of overnight oximetry at a tertiary children's hospital in SA.

METHODS: A retrospective descriptive study was conducted of patients screened for OSA by overnight oximetry at a paediatric referral hospital from December 2012 to December 2014. Clinical data were retrieved from the oximetry database and medical records. Recordings of ≥6 hours were considered adequate and included in the study. OSA severity was determined using the McGill score. Details on management and outcome were documented.

RESULTS: Oximetry studies in 137 of 153 patients were suitable for analysis (88 males (64.2%), median age 31.4 months (interquartile range (IQR) 15.8 - 65.8). Adenotonsillar hypertrophy was common (n=97, 70.8%), and 65 children (47.4%) had two or more underlying OSA risk factors. McGill's score classified patients as follows: no/mild OSA n=55 (40.1%), moderate OSA n=23 (16.8%), severe OSA n=23 (16.8%) and very severe OSA n=36 (26.3%). Male gender, adenotonsillar hypertrophy and a lower weight-for-age z-score (-1.3 v. -0.7; p=0.038) were associated with severe to very severe OSA. Seventy-eight children (56.9%) were referred for surgery, 33 (24.1%) receiving urgent surgery within a median of 6 days (IQR 4 - 12). In contrast, 59 children (43.1%) with suspected OSA did not require surgical intervention.

CONCLUSIONS: Overnight oximetry is a simple low-cost tool to assess severity of OSA and prioritise appropriate OSA management in resource-constrained settings such as SA.