A Good Night's Sleep
New research finds obstructive sleep apnea may increase the risk of sudden cardiac death
Last updated on:
October 14, 2013
October 7, 2013
Often used as a broad term to describe many forms of sleep disordered breathing caused by an overcrowded upper airway, sleep apnea is a serious medical problem in the U.S. More than 12 million Americans are affected by the disorder and upwards of 85% of those affected are undiagnosed.1,2
Recent research conducted by the Mayo Clinic Sleep Disorders Centers found that people with sleep apnea have a greater risk of sudden cardiac death. In the largest study of its kind, 10,701 adults were followed for an average of 5.3 years for incidents of resuscitated or fatal sudden cardiac death.3
Michael Enos, RRT, RPSGT, lead polysomnographic technologist and respiratory therapist at Cambridge Health Alliance, a community health system based in Cambridge, Mass., has observed many patients' hearts working harder as a result of untreated sleep apnea.
"Respiratory therapists are often on the frontlines when it comes to evaluating, treating and managing patients with sleep apnea," he remarked.
'Why Am I Here?'
Sleep apnea is a condition that requires education and management, as well as ongoing support, to improve patients' quality of sleep along with the associated symptoms that brought them to the sleep lab.
Enos is directly involved with patients in the sleep lab and sleep clinic at Cambridge Health as both a respiratory therapist and a polysomnographic technologist. As a respiratory therapist, he sees patients every day who benefit from education regarding the management of cardiopulmonary diseases, including sleep apnea. As a polysomnographic technologist, Enos may be the first person the patient has contact with talking to the doctor.
He noted that patients often enter the sleep lab with many questions, namely "Why am I here?"
"The first thing I do is explain the condition, then provide a brief overview of the equipment we will use for diagnostic PSG and PAP titration studies," said Enos.
To obtain more detail regarding sleep difficulty, each patient is given a questionnaire to fill out prior to being set up on the testing equipment. The questionnaire is often an eye-opener for the patient and a good opportunity for every member of the healthcare team to evaluate and discuss the patient's sleep, Enos observed.
"Patients often have questions after filling out the questionnaire because this may be this first time they have really thought about their sleep. They also may be intimidated by the testing equipment in the sleep lab, and I will talk with them about the electrodes that we use to monitor brain activity (EEG), eye activity (EOG), muscle activity (EMG) and cardiac activity (EKG), as well as the belts that monitor respiratory effort and body movements," he explained.
Body movements associated with sleep apnea often occur as a result of arousals from sleep due to decreased levels of oxygen in the blood. These decreased levels of oxygen often result in an increase in cardiac output and higher blood pressure.
OSA & SCD
According to the National Heart, Lung, and Blood Institute, sleep apnea is a widespread disorder that causes people to have one or more pauses in breathing or shallow breaths while sleeping. These pauses can last anywhere from several seconds to minutes and can happen 30 or more times per hour.4
Timothy K. McNelly, RCP, CRT, CPFT, manager of cardiopulmonary services at Northwest Hospital Sleep Center in Randallstown, Md., noted that the number of breathing pauses determines the severity of the disorder.
"After a person has an apnea event, it is typically followed by a normal breathing pattern that may start with a loud snort or choking sound," he explained.
This past June, a study was released and published by the Journal of the American College of Cardiology investigating the risk between obstructive sleep apnea (OSA) and sudden cardiac death in a large sampling of patients previously diagnosed with OSA. The study concluded that the magnitude of risk was predicted by the severity of the OSA, AHI and nocturnal oxygen desaturation.
Since the early 2000s, McNelly has been talking about the link between sleep apnea and sudden cardiac death.
"I'm sure that we have all witnessed patients who are suffering from an apnea event in which the patient demonstrates a severe drop in oxygen saturation and has a cardiac arrhythmia or event," he remarked.
When this is a witnessed event in the hospital setting, respiratory and nursing staff work to arouse the patient and increase the oxygen saturation, thereby relieving desaturation and arrhythmia.
"However, in the home setting or during a non-witnessed event without the proper intervention, the results could be fatal," said McNelly.
When the airway becomes blocked, the heart has to work harder because the body needs oxygen to survive, explained Enos.
"The heart pumps the blood faster and harder to supply the necessary oxygen. The increased workload on the heart may cause the heart to fatigue and ultimately fail to supply blood to the body and result in sudden cardiac death," he said.
The Respiratory Therapist's Role
Respiratory therapists are trained in the proper use of continuous positive airway pressure therapy (CPAP) and Bi-Level positive pressure therapy (Bi-PAP) for the treatment of obstructive sleep apnea and central sleep apnea. Patients are then educated by respiratory therapists in the proper use and cleaning of these devices.
"Currently, CPAP is the gold standard for treating obstructive sleep apnea. It is not uncommon to walk the halls of any hospital and see patients using either their home CPAP device or a hospital CPAP device at night," said McNelly.
When a patient is admitted to the hospital, the respiratory staff at the Northwest Hospital Sleep Center monitor and document the effective use of these devices. They also constantly reeducate and reinforce to patients the need to use their therapy at home.
"Compliance with therapy can be the difference between life and death," McNelly remarked.
Respiratory therapists who work outside the hospital in home care provide ongoing education and support in the use and cleaning of home PAP equipment, as well as fitting patients with the proper mask.
"A poor night's sleep does not come with getting older," Enos concluded. "Good sleep hygiene is essential to a good night's sleep and allows us to wake up feeling rested each day."
Beth Puliti is a frequent writer.
1. American Lung Association. (2013). Sleep Apnea. Retrieved from http://www.lung.org/lung-disease/sleep-apnea/.
2. Motamedi K, McClary A, and Amedee R. Obstructive Sleep Apnea: A Growing Problem. The Ochsner Journal. Fall 2009; 9(3): 149-153.
3. Gami A, Olson E, Shen W, et al. Obstructive Sleep Apnea and the Risk of Sudden Cardiac Death. Journal of the American College of Cardiology. August 2013; 62(7): 610-616.
4. National Heart, Lung, and Blood Institute. (2012). What Is Sleep Apnea? Retrieved from http://www.nhlbi.nih.gov/health/health-topics/topics/sleepapnea/.