Introduction Undiagnosed obstructive sleep apnoea (OSA) is increasingly recognized as a serious post-operative risk with bariatric surgery, hence increasing demand for pre-operative screening and a need for simpler ways for screening than the clinical standard, respiratory polygraphy, to mitigate strain on sleep services. WatchPAT 300 (WP) is a finger-mounted sensor that uses peripheral arterial tonometry to estimate the apnoea hyponoea index (AHI). While its use is increasing it has not yet been validated in patients with a BMI >35, the target population in bariatric surgery.
Aims To validate WP against polygraphy in pre-bariatric surgery patients with clinically suspected OSA and a BMI>35 and to assess patient acceptability of WP.
Methods AHI was measured simultaneously with WP and Embletta. Outcome measures were 1) autoscored AHI from WP and 2) manually re-scored AHI from Embletta. Agreement between AHI from Embletta and WP was assessed using intra-class correlation coefficient (ICC), bland Altman and ROC plots.
Results 28 patients (22 female/6 male, mean ± SD age 44.1 ± 11.6, BMI 45.7 ± 7.5) participated. One study failed due to the patient removing the WP probe prematurely. AHI was higher in WP than Embletta (28.1± 17.9 versus 15.0 ±13.4; p<0.05). There was a strong positive correlation between WP and Embletta AHI measurements (ICC 0.876 (95% CI 0.75-0.94; figure 1)). Bland Altman plots revealed a systematic bias; differences diverging at higher AHI values. A ROC plot revealed high sensitivity and specificity for an AHI >15 (Area under the curve 0.917; p<0.05). 97% of respondents reported that WP would be acceptable to them if introduced into the bariatric surgery pathway.
Discussion WP accurately estimates the AHI in pre bariatric surgery patients, has a low failure rate and is clinically acceptable in this group. Further larger scale studies are needed to confirm these findings before incorporating into clinical guidelines.
This is an open access article distributed in accordance with the Creative Commons Attribution Non Commercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited, appropriate credit is given, any changes made indicated, and the use is non-commercial. See: http://creativecommons.org/licenses/by-nc/4.0/.
Statistics from Altmetric.com
If you wish to reuse any or all of this article please use the link below which will take you to the Copyright Clearance Center’s RightsLink service. You will be able to get a quick price and instant permission to reuse the content in many different ways.