A Retrospective Analysis of Patients with Pulmonary Hypertension to Assess the Role of Overnight Oximetry in the Diagnosis of Sleep Disordered Breathing

Neal M Patel

doi:10.23937/2378-3516/1410004

Abstract

Background: In patients with Pulmonary Hypertension (PH), the role of overnight oximetry as means to screen for Sleep Disordered Breathing (SDB) has not been well established. The aim of this study was to assess whether overnight oximetry was additive to a standard sleep questionnaire in the diagnosis of SDB. Methods: This retrospective study included 94 PH patients seen at Mayo Clinic Florida PH Center from 1992 to 2006. Analysis was performed on the following information: age, gender, body mass index, presence of hypertension, right ventricular systolic pressure (RVSP), presence of SDB symptoms (i.e. snoring, excessive daytime sleepiness, witnessed sleep apneas), overnight oximetry results, and polysomnography results when available. The primary outcome measurement was the correlation between SBD symptoms (snoring, excessive daytime sleepiness, and witnessed sleep apnea) and results of overnight oximetry. Results: There is strong evidence showing a higher prevalence of abnormal overnight oximetry results as the number of SDB symptoms increases (P<0.001). Of patients who had no symptoms of SDB (17), all oximetry results were found to be normal. The clinical symptoms of SDB were 100% sensitive for an abnormal screening overnight oximetry. Other analysis revealed evidence of a higher prevalence of snoring in men (P=0.005) and in patients with a higher BMI (P=0.038). Conclusions: In PH patients who have a few or no symptoms of SDB, an overnight oximetry is not additive in screening for SDB. In those patients with SDB symptoms, an overnight oximetry will be predictably abnormal.

Highlights

Sleep Disordered Breathing (SDB) is a known risk factor in the development of Pulmonary Hypertension (PH) [1]
The following number of patients were excluded from analysis: 183 patients because an overnight oximetry was not obtained at time of initial evaluation; 27 patients who were on oxygen at time of overnight oximetry; 4 patients who were being treated with non-invasive positive pressure therapy at the time of evaluation; 2 patients who had less than 4 hours of recording of overnight oximetry; and 2 patients who were found to have a normal Right Ventricular Systolic Pressure (RVSP) as measured by echocardiogram
Of the 94 patients, 17 (18%) had abnormal overnight oximetry suggesting the presence of SDB

Summary

Introduction

Sleep Disordered Breathing (SDB) is a known risk factor in the development of Pulmonary Hypertension (PH) [1]. In patients with PH, the role of overnight oximetry as a means to screen for SDB has not been well established [2]. There exists evidence that overnight oximetry is a sensitive means of screening individuals for the presence of SDB [6,7]. To date this data has not been extrapolated to patients with PH. We sought to evaluate whether overnight oximetry was additive to a standard sleep questionnaire in the diagnosis of SDB in patients with PH. In patients with Pulmonary Hypertension (PH), the role of overnight oximetry as means to screen for Sleep Disordered Breathing (SDB) has not been well established.

Objectives

Methods

Results

Conclusion