Limited ambulatory night sleep testing in patients with a suspicion of sleep apnoea syndrome: Is its indication tenable?

Summary

Introduction:

Ambulatory sleep testing is nowadays an available diagnostic method, measuring air flow and blood oxygen saturation in patients with a suspicion of obstructive sleep apnoea syndrome (OSAS). It can be performed by either a general practitioner or an ambulatory specialist in various fields. Using this simple screening method it is possible to exclude subjects without OSAS, who therefore do not require further sleep testing at a sleep laboratory. There is no published data regarding the use of ambulatory sleep testing by sleep laboratories in the Czech Republic.

The aim of this study was to evaluate the proportion of patients examined by ambulatory sleep testing and to determine the factors influencing its indication.

Material and methods:

The study involved 497 patients (363 males) with an average age of 55.5 ± 12.3 years. These patients were tested by the sleep laboratory at University Hospital Olomouc with a suspicion of OSAS. The clinical complaints of the patients were evaluated (e.g. excessive daytime sleepiness, microsleeps, etc.) along with a basic examination, including anthropometric parameter measurements, on admission to the ward. Whilst admitted, night sleep testing using respiratory polygraphy or videopolysomnography was performed in all patients. Furthermore, the number of patients that underwent ambulatory sleep testing prior to admission to the sleep laboratory and the number of patients with an indication for positive airway pressure therapy (PAP) (apnoea-hypopnea index > 15) was assessed. The results were processed using the software IBM SPSS Statistics v22.

Results:

Ambulatory sleep testing was performed in only 96 patients (19.3 %). Among these patients, 76 (79.0 %) were diagnosed with OSAS with an indication for PAP. In the 401 patients who did not undergo ambulatory sleep tests, 227 (53.9 %) were diagnosed with OSAS with an indication for PAP. Patients who underwent ambulatory sleep tests and those who did not differed only in age (p = 0.03). There were no significant differences in other parameters (sex, height, weight, BMI, circumference of neck, waist and hips, ESS), including sleepiness (p = 0.605) and microsleeps (p = 0.74).

Conclusion:

Ambulatory sleep testing is performed in only a small proportion of patients. Its use can reduce healthcare costs as well as waiting times for sleep laboratory tests.

Keywords:

ambulatory night sleep testing – sleep apnoea