Increased load on the respiratory muscles in obstructive sleep apnea
Joerg Steier1, Caroline J Jolley, John Seymour
1King's College London School of Medicine, London, UK. joerg.steier@kcl.ac.uk
Respiratory Physiology & Neurobiology
|February 2, 2010
Summary
Patients with obstructive sleep apnea (OSA) exhibit higher neural respiratory drive during sleep. Increased respiratory muscle activity is necessary to maintain ventilation and airway patency in individuals with OSA.
Area of Science:
- Respiratory Physiology
- Sleep Medicine
- Neuromuscular Control
Background:
- Obstructive sleep apnea (OSA) is characterized by recurrent upper airway collapse during sleep.
- The role of respiratory muscle activity in maintaining upper airway patency in OSA is not fully understood.
Purpose of the Study:
- To quantify respiratory muscle activity in relation to upper airway occlusion and patency in patients with OSA.
- To test the hypothesis that specific levels of neuromuscular activation are associated with upper airway patency.
Main Methods:
- Recruited 21 patients with diagnosed OSA and 21 healthy controls.
- Utilized polysomnography and respiratory muscle testing, including diaphragm electromyogram (EMG(di)).
- Measured neural respiratory drive during wakefulness, sleep, and preceding/during airway occlusion.
Main Results:
- Obese OSA patients showed elevated EMG(di) while awake and supine compared to controls (13.1%max vs. 8.1%max).
- During unobstructed sleep breathing (N2), EMG(di) was significantly higher in OSA patients (22.8%max) than controls (7.7%max).
- EMG(di) and submandibular EMG decreased before occlusion and increased significantly at airflow onset post-occlusion.
Conclusions:
- Patients with OSA demonstrate increased neural respiratory drive during sleep.
- Elevated respiratory muscle activation is required to sustain ventilation and counteract upper airway collapse in OSA.
- Specific levels of neuromuscular drive are crucial for maintaining airway patency in OSA patients.
Related Concept Videos
01:21Sleep Apnea
Sleep apnea is a condition where breathing stops intermittently during sleep, often leading to significant health issues. Each episode can last from 10 to 20 seconds or more and is frequently accompanied by a brief arousal from sleep. This disturbance, largely unnoticed by the individual, can lead to severe daytime fatigue. Commonly, individuals seek help after being informed by their partners about loud snoring and noticeable breathing pauses during sleep.
The condition is more prevalent among...
The condition is more prevalent among...
01:25Hyperpnea and Hyperventilation
Hyperventilation refers to a higher-than-normal rate and depth of breathing, often associated with anxiety attacks. This excessive breathing surpasses the body's need to expel CO2, leading to a condition known as hypocapnia - an unusually low level of carbon dioxide in the blood. Hypocapnia can constrict cerebral blood vessels, reducing blood flow to the brain, which may result in dizziness or fainting. Early signs include tingling and muscle spasms in the hands and face, caused by falling...
01:24Factors Affecting Respiration
Respiration is a crucial physiological function involving exchanging oxygen (O2) and carbon dioxide (CO2) between an organism and its environment. Various factors can impact this essential process:
01:26Respiratory Volumes and Capacities I
Assessing the respiratory rate and rhythm for a complete minute is crucial for evaluating the breathing pattern. Even a minor increase in the patient's average respiratory rate, by as little as three to five breaths per minute, is an early and vital indicator of respiratory distress. Patients with a respiratory rate exceeding twenty-four breaths per minute require close monitoring to determine the physiological alterations. This careful observation is essential for prompt recognition and...
01:27Physical Assessment of the Respiratory Tract II: Inspection
Physical assessment of the respiratory tract through inspection is a crucial step in understanding the patient's respiratory health. It provides insights into the functioning of the respiratory system, the musculoskeletal structure, and even the patient's nutritional status. This comprehensive approach involves observing several vital aspects: chest configuration, breathing patterns, respiratory rates, skin color, and use of accessory muscles.
Chest Configuration
The chest configuration can...
Chest Configuration
The chest configuration can...
01:21Mechanism of Breathing III: The Accessory Muscles
The Role of Accessory Muscles in the Respiratory System
The respiratory system is a complex network that relies on primary respiratory muscles like the diaphragm, but also involves accessory muscles to enhance lung expansion and airflow during both inhalation and exhalation.
Enhancing Inhalation with Accessory Muscles:
Accessory muscles such as the sternocleidomastoid, scalene, intercostal, and abdominal muscles are crucial when additional respiratory effort is required, such as during deep...
The respiratory system is a complex network that relies on primary respiratory muscles like the diaphragm, but also involves accessory muscles to enhance lung expansion and airflow during both inhalation and exhalation.
Enhancing Inhalation with Accessory Muscles:
Accessory muscles such as the sternocleidomastoid, scalene, intercostal, and abdominal muscles are crucial when additional respiratory effort is required, such as during deep...