Obstructive sleep apnea (OSA) is a highly prevalent disorder that often is unrecognized. Recently, a novel protocol for screening hospitalized patients for OSA resulted in early initiation of positive airway pressure (PAP) therapy and early post-discharge follow-up. The protocol utilizes a combination of high-resolution pulse oximetry (HRPO) and home sleep apnea tests (HSATs); the former has been well-validated in previous studies against HSAT and polysomnography. While a definitive treatment plan can be generated for patients with a positive HRPO for OSA, it is less clear how best to manage patients with a negative HRPO.

A retrospective analysis of a registry of patients screened for OSA was conducted. Consecutive patients with HRPO-derived ODI (oxygen desaturation index) < 5/h who underwent same-night HRPO and HSAT were identified. The demographic and clinical characteristics of patients with ODI < 5/h and AHI (apnea hypopnea index) < 5/h were compared with patients with ODI < 5/h and AHI ≥ 5/h.

The analysis revealed 190 patients with ODI < 5/h. Only 23 (12%) of these patients had AHI ≥ 5/h. When compared with patients who had ODI < 5/h and AHI < 5/h, there was no difference in most testing and patient characteristics. However, antiplatelet use and total time in minutes with saturation < 88% greater than 100 min were associated with a higher likelihood of discordant ODI and AHI.

HRPO-derived ODI has a low rate of false negativity. Clinicians should be aware of the possibility of a false negative ODI for patients with antiplatelet use and time with saturation < 88% greater than 100 min and antiplatelet therapy.