Aims Oximetry is widely used to screen for obstructive sleep apnoea (OSA) in children with good specificity but reduced sensitivity compared to polysomnography (PSG).¹ Treatment decisions are usually made using oximetry criteria alone.² Our aim is to investigate whether screening sleep studies incorporating extra modalities improve the accuracy of detecting OSA compared to oximetry alone.

Methods A retrospective review of 197 inpatient sleep studies performed at a district general hospital in 2013 was carried out using data from patient notes and a database. The sleep studies were performed with VISILAB equipment incorporating ECG, audio, video, pulse transit time (PTT) and oximetry. Study findings were categorised as ‘normal’; ‘primary snoring’; ‘upper airway resistance syndrome’ (UARS); ‘obstructive sleep apnoea’ or ‘other abnormality’. The findings are compared with oximetry risk categories using standard criteria for OSA screening.

Results The main findings are shown in Figures 1 and 2.

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Abstract G398(P) Figure 1

Categories of risk based on oximetry data

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Abstract G398(P) Figure 2

Diagnosis based on sleep study findings

A total of 19 children with abnormal oximetry findings were considered to have a normal study with the use of video, sound and PTT. Technical reasons were frequently identified for the abnormal oximetry findings. An identical number of children with normal or borderline oximetry were categorised as having UARS or OSA and were managed with a combination of watchful waiting, surgery or medical treatment.

Conclusion Screening sleep studies incorporating video, sound and arousal detection provide increased diagnostic accuracy over oximetry only studies. These studies may be of particular benefit in a DGH setting with no access to polysomnography.

References

1. Brouillette RT, Morielli A, Leimanis A, et al. Nocturnal pulse oximetry as an abbreviated testing modality for pediatric obstructive sleep apnea. Pediatrics 2000;105:405–412

2. RCPCH Working Party on Respiratory Physiology and Sleep Control Disorders in Children Sept 2009