[Value of cardiorespiratory analysis in the diagnosis of breathing sleep disorders in patients with chronic renal failure].

BACKGROUND AND OBJECTIVE

Prevalence of sleep apnea-hypopnea syndrome (SAHS) in end-stage renal disease (ESRD) is high and the polygraphy has not been validated as diagnostic technique in this group of patients. The objective of this study was to evaluate if only the cardiorespiratory analysis is valid for the diagnosis of SAHS.

PATIENTS AND METHOD

48 patients with ESRD were studied consecutively with all-night polysomnography. We compared the desaturation index of SaO2 > or = 4% (DI4), sleep time spent with SaO2 < 90% (T90) and the apnea-hypopnea index (AHI) per hour of sleep with the results of the cardiorespiratory analysis.

RESULTS

We included 35 men and 13 women, age: 54 (16) years and IMC: 27.1. Eighteen patients were diagnosed of SAHS (37.5%). The cardiorespiratory analysis obtained a sensibility of 77.7%, specifity of 100%, positive predictive value was 100% and negative predictive was 88%. The polysomnography showed an AHI: 16 (17.2), while the cardiorespiratory analysis was 11 (13.2). There were a good correlation (r = 0.970) and concordance scores (CCI = 0.967; p < 0.001). The cardiorespiratory analysis, respect the polysomnography, also obtained a good correlation and concordance for ID4 (10 [11.8] vs 15 [15.5]) and for T90 (1 [2.9] vs 2 [4.7]; p < 0.001). In the COR curve, the best cut-off point of the cardiorespiratory analysis was an AIH = 7.2.

CONCLUSIONS

In patients with ESRD, the cardiorespiratory analysis, is valid for the diagnosis and correctly detect the SaO2 at night, both being key parameters for the diagnostic and treatment of SAHS. The polygraphy could be an alternative diagnostic test in the SAHS, although it has to be definitively validated.