# Management of Obstructive Sleep Apnea in Hospitalized Patients
## 6 Considerations in Specific Inpatient Populations  
### OSA and CHF  
SDB, including central sleep apnea (CSA), is common in hospitalized patients with CHF exacerbation, and in one study, 76% had an AHI of more than 15 [82]. In another study of hospitalized CHF patients who underwent a Type III sleep study, 75% had SBD, of which 57% had OSA. A PSG at 8 weeks validated the predictive value of in-hospital testing [23]. Treating OSA has benefits and limitations in CHF patients. In a randomized control trial of patients--with acute CHF exacerbation who underwent in-hospital sleep studies and were randomized to receive either goal-directed medical therapy (GDMT) with PAP or just GDMT--left ventricular ejection fraction (LVEF) increased by 4.5% in the treatment group versus 0.3% in the nontreatment group at 3 days post randomization [57]. Early intervention with PAP therapy for 48 h and GDMT resulted in a significantly higher reduction in pulmonary artery pressures and improvement in acute CHF symptoms compared to GDMT alone in one study of CHF patients with OSA [60]. It also resulted in improvements in the right and left ventricular functions. In another study, patients admitted to the hospital for treatment of CHF exacerbation underwent a hospital Type III sleep study and were prescribed and discharged on auto-PAP [83]. Patients with PAP adherence had a lower readmission rate at 30 days as compared to those who were noncompliant [83]. In another study, early intervention with PAP therapy by screening patients within four weeks of discharge from the hospital also reduced the six-month readmission risk in patients who were compliant with treatment [84]. In a single-center study, patients admitted to the hospital were screened; high-risk patients underwent HRPO testing, and patients with high ODI were referred for PSG and PAP therapy [25]. Patients who were compliant with treatment in the first 3 months had improved survival over a mean follow-up of almost 2 years [25]. In this study, the HRPO ODI showed an AUC of 0.83 when compared to the AHI from PSG, suggesting that HPRO is a valid tool that can be easily implemented in the hospital. CPAP effectively treats acute cardiogenic pulmonary edema and lowers the risk of mechanical ventilation [85; 86]. Possible benefits of CPAP included a reduction in sympathetic activity as recurrent arousals are stopped and hypoxemia improved.  
Although treatment of OSA with PAP improves outcomes, the treatment of CSA has been linked to an increased risk of death in patients with an ejection fraction (EF) of 45% or less [87]. In this study, patients with an EF of 45% or less and an AHI \(\geq\) 15, with most of the patients having CSA, were treated with adaptive servo ventilation (ASV). The treatment group had a higher incidence of all-cause and cardiovascular mortality. While the mechanism underlying this increased mortality is unknown, there are indications that Cheyne-Stokes breathing may be protective in CHF patients, with attenuation resulting in a poor outcome [87]. A recent computer model studying the effects of ASV on CHF patients with OSA shows a complex mechanism of adverse outcomes in patients with extremely low EF, such as increased sympathetic tone, dampened vagal tone, and reduced coronary flow, possibly leading to arrhythmias. As the increased mortality in the original study was unrelated to recurrent admissions or remodeling, sudden cardiac death remains the most plausible cause [88]. Overall, current practice guidelines do not recommend using ASV to treat SDB in patients with EF < 45%. PAP therapy can still be used to treat OSA. CPAP at a fixed pressure is safe and should still be considered for treating CSA in this population [89].