Observational Study of Pulse Transit Time in Children With Sleep Disordered Breathing

Retrospective review of treatment outcomes and costs in children with sleep disordered breathing assessed with multi-channel studies

Current UK guidance on OSA management recommends only selective use of sleep studies - when there is diagnostic uncertainty, in children with comorbidities or to evaluate perioperative risk in those with suspected severe OSA. Routine use of sleep studies to confirm a diagnosis of obstructive sleep apnoea (OSA) in children before adenotonsillectomy is not currently recommended. We report the findings of a novel paediatric sleep service based on routine use of multi-channel sleep studies (MCSS) before adenotonsillectomy and present the results of a service evaluation assessing the impact of our practise on treatment outcomes and cost. We conducted a retrospective study of 264 children with sleep disordered breathing seen in our centre between July 2018-June 2019, using medical records and a sleep study database to determine treatment outcomes and costs. Using responses from a questionnaire completed by otolaryngologists for a separate prospective study, we compare our costs with estimates of those associated with a standard UK model of care i.e. with selective use of sleep studies. We estimate that our routine use of MCSS reduced the number of adenotonsillectomies by 44 % but at higher monetary costs than those estimated for the standard model of care. We note however, that reconfiguring our service to arrange a sleep study before the initial appointment, rather than after, would result in the service being cost neutral compared with the standard model. We also estimate that use of home multi-channel studies in our service would bring a significant cost saving (∼£50,000 - £80,000 per annum) compared to standard care.

Prospective evaluation of the impact of multi-channel studies on treatment outcomes in children with sleep disordered breathing

There are significant variations in practice regarding the use of sleep studies in children with symptoms of sleep disordered breathing (SDB) prior to adenotonsillectomy. Current UK guidance recommends the selective use of sleep studies to confirm a diagnosis of obstructive sleep apnoea (OSA) when there is diagnostic uncertainty, in children with comorbidities, or to assess perioperative risk when severe OSA is suspected. We have developed a novel paediatric sleep service over the past decade based on the routine use of multi-channel sleep studies (MCSS) before adenotonsillectomy. We present the results of a prospective evaluation assessing the impact of our service on treatment outcomes. We conducted a prospective service evaluation of 49 children with SDB seen between July 2021 and August 2022. We used medical records and a sleep study database to determine treatment outcomes. Otolaryngologists completed a questionnaire before each multi-channel sleep study to help evaluate the impact of sleep study findings on surgical decision making. Questionnaire responses before MCSS showed that clinicians thought 66 % of children were 'likely', 'very likely' or 'definitely' would require surgery but only 54 % of children underwent surgery following their sleep study. We estimate that the use of MCSS was associated with a 21 % reduction in children undergoing surgery in this small sample. We conclude that our use of MCSS facilitates conservative management, allowing a significant reduction in the number of children with SDB undergoing surgery, but further validation of MCSS against polysomnography is required.

Severe obstructive sleep apnea in children with syndromic craniosynostosis: analysis of pulse transit time

STUDY OBJECTIVES

We examined the association between pulse transit time (PTT) and obstructive sleep apnea (OSA) in children with syndromic craniosynostosis (SCS), where OSA is a common problem and may cause cardiorespiratory disturbance.

METHODS

A retrospective study of children (age < 18 years) with SCS and moderate-to-severe OSA (ie, obstructive apnea-hypopnea index ≥ 5) or no OSA (obstructive apnea-hypopnea index < 1) who underwent overnight polysomnography. Children without SCS and normal polysomnography were included as controls. Reference intervals for PTT were computed by nonparametric bootstrap analysis. Based on reference intervals of controls, the sensitivity and specificity of PTT to detect OSA were determined. In a linear mixed model, the explanatory variables assessed were sex, age, sleep stage, and time after obstructive events.

RESULTS

In all 68 included children (19 with SCS with OSA, 30 with SCS without OSA, 19 controls), obstructive events occurred throughout all sleep stages, most prominently during rapid eye movement (REM) sleep and non-REM sleep stages N1 and N2, with evident PTT changes. The greatest reductions were observed 4-8 seconds after an event (P < .05). In SCS with OSA, PTT reference intervals were lower during all sleep stages compared with SCS without OSA. The highest sensitivity was observed during N1 (55.5%), and the highest specificity during REM sleep (76.5%). The lowest PTT values were identified during N1.

CONCLUSIONS

Obstructive events occur throughout all sleep stages with transient reductions in PTT. However, PTT as a variable for OSA detection is limited by its sensitivity and specificity.

CITATION

Yang S, van Twist E, van Heesch GGM, et al. Severe obstructive sleep apnea in children with syndromic craniosynostosis: analysis of pulse transit time. J Clin Sleep Med. 2024;20(8):1233-1240.

Pulse transit time as a diagnostic test for OSA in children with Down syndrome

STUDY OBJECTIVES

Children with Down syndrome (DS) are at risk of obstructive sleep apnea (OSA), but the access to sleep lab polysomnography (PSG) is limited. Simplified techniques are needed, such as polygraphy coupled with pulse transit time (PTT-PG) that detects respiratory events and the total autonomic arousals index (PTTAI). Our objective was to assess the ability of PTT-PG compared with PSG to diagnose OSA in children with DS.

METHODS

In this prospective multicenter study, patients with DS underwent a full-night PSG coupled with PTT. Sleep questionnaires (Sleep Disturbance Scale for Children and Pediatric Sleep Questionnaire) were filled by parents. PSG and PTT-PG results were compared to test their sensibility and specificity to diagnose OSA.

RESULTS

A total of 53 patients with DS were included; their median age was 9.3 years. An obstructive apnea-hypopnea index (OAHI) by PSG > 1 event/h was found in 36 (68%) patients, OAHI was > 1 and < 5 events/h in 18 patients (34%), ≥ 5 and < 10 events/h in 11 patients (21%), and ≥ 10 events/h in 7 patients (13%). OAHI was larger on PSG than on PTT-PG (P = .0005). For OSA diagnosis, the sensitivity was excellent for OAHI by PTT-PG if the added total PTTAI was > 1 event/h (1.0) and the specificity was high for the Pediatric Sleep Questionnaire (0.88) and OAHI > 1 event/h on PTT-PG (1.0).

CONCLUSIONS

More than two-thirds of children with DS referred for screening by a genetics specialist had OSA diagnosed by PSG. With its excellent sensitivity and specificity, PTT-PG could be a good and simplified alternative to PSG to diagnose OSA in children with DS.

CITATION

Ioan I, Weick D, Sevin F, et al. Pulse transit time as a diagnostic test for OSA in children with Down syndrome. J Clin Sleep Med. 2022;18(1):119-128.