How to interpret a negative high-resolution pulse oximetry in hospitalized patients screened for obstructive sleep apnea: an exploratory analysis.

INTRODUCTION: 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. MATERIALS AND METHODS: 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. RESULTS: 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. CONCLUSION: 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.

Three cases of black pleural effusion.

Black pleural effusions (BPE) are rare, exudative pleural effusions that produce a black fluid on thoracentesis. While the name and definition of this pathology is undeniably simple, the etiologies, outcomes, and treatments for BPE are incredibly complex. Currently, BPE is not well-demonstrated in the literature. This case series reports three patients with different etiologies, past medical histories, presenting symptoms, treatments, and outcomes. BPE caused by pancreatic-pleural fistula and opportunistic infections are demonstrated in this case series. This report shows that early identification and treatment of the underlying cause of BPE is critical to the recovery of the patients.