Association between Chronic Cough and OSA
An overview of respiratory diseases related to sleep apnea syndrome
APEX is honored to invite Dr. Wen-te, Liu, attending physician at the TMU’s Division of Thoracic Medicine in Shuang Ho, to give us an overview of respiratory diseases related to OSA. Below are excerpts from Dr. Liu’s speech.
Mouth Breathing and Chronic Coughing
Those with chronic allergies and stuffy noses may breathe through their mouths, causing dry mouth, mucosal injuries, and highly sensitive cough reflexes in which you cough whenever you speak or if post-nasal drips occur.
Clinical Signs of Allergic Rhinitis
- Approximately 1/4 of patients with allergic rhinitis show symptoms only when asleep
- Sleep is often disrupted leaving patients feeling sleepless
- Dry mouths when sleeping or upon waking
- Phlegm in the throat upon waking
- Asthma attacks while sleeping or upon waking. Slight breathlessness and sometimes coughing blood upon waking
Acid Reflux and Allergic Rhinitis Are Causes to Each Other
In clinical practices we often use cough induction as tests: using osmotic pressure, stimulants, or citric acid to stimulate the throat and check if the esophageal nerves are overly sensitive. The cause for this sensitivity may be nasal mucosal contractions caused by acid reflux stimulating the esophagus. In addition, acid reflux and allergic rhinitis are common comorbidities because acid reflux stimulates the esophagus causing nasal mucosal contractions. Make sure to test multiple facets to ensure proper treatment is provided.
Upper Airway Resistance Syndrome
There is some correlation between upper airway resistance syndrome and respiratory effort related arousal (RERA). People with retracted or small jaws cannot effectively support their respiratory tract while sleeping because their muscle tone is relaxed. When they are awake, the muscle tone can support the respiratory tract, ensuring unobstructed breathing. When sleeping their respiratory tract will be obstructed, increasing respiratory efforts. Even though RERA doesn't cause blood oxygen content to dip while sleeping, it disrupts sleep by waking up brain waves and in turn causes a lowered quality of sleep.
Association between Chronic Coughing and OSA
A longitudinal study of CPAP therapy for patients with chronic cough and obstructive sleep apnea in Cough showed that there is now proof of association between chronic coughing and untreated OSA. Treating sleep apnea in patients can markedly improve their chronic cough and health.