Conference Coverage

Subset of patients benefits from in-hospital sleep apnea screening



– In the clinical opinion of Richard J. Schwab, MD, any hospitalized patient with a body mass index of 35 kg/m2 or greater should undergo overnight pulse oximetry testing.

A man uses a CPAP device Courtesy Dr. Krishna Sundar

“Many diseases are adversely affected by sleep apnea, including myocardial infarction, hypertension, a cerebrovascular accident, pulmonary hypertension, atrial fibrillation, diabetes, and congestive heart failure,” Dr. Schwab, interim chief of the University of Pennsylvania Perelman School of Medicine’s Division of Sleep Medicine, said at the annual meeting of the Associated Professional Sleep Societies.

“Continuous positive airway pressure [CPAP] may help heart failure patients and reduce 30-day readmission rates, which has important financial implications in the University of Pennsylvania Health system. CPAP may also decrease the rapid responses and cardiac arrests at night,” he said.

A few years ago, Dr. Schwab and his associates set out to determine whether PAP adherence in cardiac patients with sleep-disordered breathing reduced readmission rates 30 days after discharge (J Clin Sleep Med. 2014;10:1051-59). They evaluated 104 consecutive cardiovascular hospitalized patients reporting symptoms of sleep-disordered breathing (SDB) between January of 2012 and March of 2013, and collected demographic data, SDB type, PAP adherence, and data regarding 30-day hospital readmission/ED visits. Apnea was scored when there was a 90% or greater cessation of airflow detected through the nasal pressure sensor. Hypopnea was scored when there was at least a 50% reduction in airflow with an associated 3% or greater oxyhemoglobin desaturation. Central apnea (CSA) was scored when there was a 90% or greater cessation of airflow detected through the nasal pressure sensor and no effort in the thorax and abdomen. If more than 50% of the apneas were central, the SDB was classified as CSA. If more than 50% of apneas were obstructive in nature, it was considered obstructive sleep apnea (OSA).

The mean age of the patients was 59 years, 63% were male, their mean body mass index was 34 kg/m2, 87% had heart failure, and 82% had hypertension. Of the 104 patients, 81 had SDB and 23 did not. The 30-day readmission rate was 29% in patients who did not use PAP, 30% in partial users, and 0% in full users (P = .0246).

The researchers found that 81 patients (78%) had sleep disordered breathing. Of these, 65 (80%) had OSA while 16 (20%) had CSA. The study demonstrated that performing inpatient sleep studies was feasible. “Our study indicated that SDB is common in hospitalized cardiac patients, with the majority of patients manifesting OSA,” said Dr. Schwab, medical director of the Penn Sleep Centers. “The data suggest that hospital readmission and ED visits 30 days after discharge were significantly lower in patients with cardiac disease and SDB who adhere to PAP treatment than those who are not adherent.”

Dr. Schwab is part of a research team conducting a longer study with ResMed to examine 30-, 60-, and 90-day readmission rates in cardiac inpatients newly diagnosed with OSA and started on auto-PAP (APAP). They plan to evaluate the ejection fraction during hospitalization and in follow-up, as well as the effect of an in-laboratory sleep study at 1 month. The long-term follow-up is planned for 3 years.

Launching an inpatient sleep apnea consult service in the hospital makes sense, Dr. Schwab continued, because home sleep studies are approved for the diagnosis of sleep apnea, APAP can determine optimal CPAP settings, insurance will cover CPAP with a home or inpatient sleep study, and patients can get CPAP/APAP at or before discharge. “Sleep techs or respiratory therapists can perform these sleep studies,” he said. At Penn, a nurse practitioner (NP) runs this service using the Alice NightOne home sleep testing device and the WatchPAT portable sleep apnea diagnostic device.

The notion of performing in-hospital sleep studies should be an easy sell to cardiologists and hospital administrators, Dr. Schwab said, because the program will decrease hospital readmissions, “which is going to save the hospital a lot of money. In addition, these patients can come back for in-laboratory sleep studies. There is also increased revenue from the consults and progress notes, and the professional fee for sleep study interpretation. The most challenging part of the inpatient sleep consult service is trying to get these patients to follow up in the sleep center with the NP.”

Dr. Schwab is an investigator for the recently launched Penn Medicine Nudge Unit Project, which is funded by the National Institutes of Health. The project includes a multidisciplinary team of providers from the Hospital of the University of Pennsylvania, Penn Presbyterian Medical Center, and Penn Medicine Risk Management. If an inpatient has a BMI of 35 kg/m2 or greater, the clinician will be “nudged” via an enterprise messaging system (EMS) prompt to order an inpatient sleep oximetry. “They have to respond to that nudge,” Dr. Schwab said. “If the oximetry is consistent for sleep apnea, there will be another nudge to consult with the sleep medicine team. If the oximetry is negative, they will be nudged to get an outpatient consult with the sleep medicine team.” For patients undergoing preadmission testing for any type of surgery who score 4 or more on the STOP-Bang questionnaire (Chest 2016;149:631-38), the clinician is “nudged” to order an outpatient sleep consultation.

Benefits to such an approach, he said, include a decrease in resource allocation, shorter hospital stays, patient perceived improvement in quality of sleep, improved patient survey scores, and the fact that apnea treatment may decrease the need for rapid response. “It also reduces medical-legal concerns, improves patient outcomes, decreases readmissions, and generates revenue from inpatient and outpatient sleep studies,” Dr. Schwab said. Barriers to such an approach include the fact that there is no defined pathway at many institutions for recognizing and referring suspected OSA patients. “There is often a lack of care coordination between primary providers and sleep medicine, and sleep is viewed as ambulatory care, not as a part of inpatient care,” he said.

Last year, Dr. Schwab and his colleagues at UPenn conducted a pilot study to develop and test a pathway for identifying OSA in high-risk inpatient and preadmission patient populations. Of 389 patients admitted between Aug. 20 and Sept. 20 of 2018, 43 had a BMI of 35 kg/m2 or greater. Of these, 10 were screened with oximetry and 8 were positive for severe apnea. Of these eight cases, five inpatient consults were ordered, one outpatient consult was ordered, one patient had no consult ordered, and one patient was discharged before the consult was ordered.

Dr. Schwab also performed a pilot study in patients undergoing preoperative testing with the STOP-Bang questionnaire. “When we piloted this, there were over 200 patients who could have been sent to the outpatient sleep consult service, and we referred none,” Dr. Schwab said. “We are just starting to implement a program to screen them. We can treat these people for their sleep apnea and prevent chronic adverse sequelae associated with this disease.”

Both the inpatient and outpatient screening programs for sleep apnea are built within their electronic medical record. “Building this within your EMR requires effort, but it’s doable,” he said.

Dr. Schwab disclosed that he has received grants from the National Institutes of Health, ResMed, and Inspire Medical Systems.

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