The Link Between Pulmonary And Sleep Disorders
The cause of death may not read “apnea” or “hypoxia.”
Head trauma from swerving into an oncoming lane while nodding off on the way to work, or stroke or heart disease may be the official story. The true cause, however, may have started in the middle of the night.
Sleep disorders have become so common that hospitals are adding sleep labs to handle the demand for diagnostic sleep studies. In addition to Princeton Baptist, Shelby Baptist, Citizens Baptist in Talladega, UAB and other facilities in the region, Trinity Medical Center is opening a new Sleep Disorders Center to diagnose and manage sleep and related pulmonary disorders.
“Patients with Sleep Disordered Breathing (SDB) often complain of daytime sleepiness, morning headaches, poor concentration and fatigue,” said Alan Thomas, MD, of Pulmonary Associates of the Southeast, who will be working with patients suffering from pulmonary-related sleep disorders at the new Trinity Clinic.
“SDB includes simple snoring, upper airways resistance syndrome, obstructive sleep apnea (OSA) and central sleep apnea,” Thomas said. “These disorders are characterized by reduction or cessation of airflow to the lungs, caused most frequently by partial or complete collapse of the soft palate during deep sleep, and in some cases, by the absence of the signals to breathe from the brainstem.”
Stuart Padove, MD, pulmonologist at Princeton Baptist Medical Center’s SleepAware program, added, “There are estimates that as many as 30 million Americans have sleep apnea. Only a fraction of these have been diagnosed and treated. Untreated apnea affects the vascular system and can lead to hypertension, heart disease, coronary artery disease, stroke, kidney disease, arrhythmias, diabetes and diabetic complications. Untreated patients have an increased risk of premature death from disease, as well as accidents.”
Obesity and aging are thought to be predisposing factors to the development of apnea, two trends that could lead to an increasing number of cases in the future. However, even normal weight people who have predisposing anatomic abnormalities can be at risk.
“Statistically, patients who are overweight have an increased risk of having apnea,” Padove said. “Though we used to think of sleep apnea as a disease of the obese, more patients who are thin are also being diagnosed. Other factors include anatomical narrowing of the posterior pharynx and larynx. Apnea causes an increased tendency for weight gain in the thin patient.”
Thomas noted that sleep can also be a difficult and possibly dangerous time for patients with other pulmonary disorders.
“COPD and obstructive sleep apnea presenting together are known as the overlap syndrome,” he said. “This is fairly common and frequently causes more severe sleep derangements and hypoxia than either disease alone. Hypoxia caused by common respiratory diseases such as COPD and pulmonary fibrosis is known to worsen during sleep. This is secondary to the normal physiologic reduction in ventilation that occurs nocturnally. In addition, the symptoms of asthma frequently worsen during sleep due to circadian variation in pathophysiology of this disease.”
What are some of the clues that patients may need an evaluation?
Padove said, “Any complaint of snoring, unrefreshing sleep, frequent arousals from sleep, frequent body movements during sleep, witnessed apnea, and excessive daytime sleepiness are key signs and need to be evaluated. Patients with COPD can also have unrecognized apnea and should be considered as at risk.”
When breathing problems during sleep are diagnosed, the next step is to choose the best corrective measures for that particular patient.
“Generally, CPAP is effective in correcting apnea in 70-90% of patients.
It applies positive air pressure, which overcomes the airway’s tendency to collapse during inspiration,” Padove said. “Alternative treatments can sometimes be used, including oral appliances which reposition the jaw and create a slight increase in the size of the posterior of the mouth and throat. Also, cranial facial surgery can be tried in selected cases.”
Thomas added, “Simple nocturnal oxygen is frequently prescribed for chronic respiratory diseases and improvements in sleep quality can occur. Patients with neuromuscular disease who suffer respiratory muscle fatigue during sleep and associated hypoxia and hypercapnia can be treated with more advanced non-invasive ventilation devices that utilize BIPAP with a set respiratory backup rate.”
In addition to helping with sleep-related breathing problems, local sleep labs also assist physicians and patients in diagnosing and managing other sleep-related disorders, ranging from narcolepsy and night terrors to insomnia, sleep walking and restless legs syndrome.
Identifying the problem is the first step in helping patients breathe easier, sleep safely, and wake refreshed and ready to start their day.