Tetraplegia is associated with increased hypoxic ventilatory response during nonrapid eye movement sleep
Abstract
People with cervical spinal cord injury (SCI) are likely to experience chronic intermittent hypoxia while sleeping. The physiological effects of intermittent hypoxia on the respiratory system during spontaneous sleep in individuals with chronic cervical SCI are unknown. We hypothesized that individuals with cervical SCI would demonstrate higher short‐ and long‐term ventilatory responses to acute intermittent hypoxia (AIH) exposure than individuals with thoracic SCI during sleep. Twenty participants (10 with cervical SCI [9 male] and 10 with thoracic SCI [6 male]) underwent an AIH and sham protocol during sleep. During the AIH protocol, each participant experienced 15 episodes of isocapnic hypoxia using mixed gases of 100% nitrogen (N2) and 40% carbon dioxide (CO2) to achieve an oxygen saturation of less than 90%. This was followed by two breaths of 100% oxygen (O2). Measurements were collected before, during, and 40 min after the AIH protocol to obtain ventilatory data. During the sham protocol, participants breathed room air for the same amount of time that elapsed during the AIH protocol and at approximately the same time of night. Hypoxic ventilatory response (HVR) during the AIH protocol was significantly higher in participants with cervical SCI than those with thoracic SCI. There was no significant difference in minute ventilation (V.E.), tidal volume (V.T.), or respiratory frequency (f) during the recovery period after AIH in cervical SCI compared to thoracic SCI groups. Individuals with cervical SCI demonstrated a significant short‐term increase in HVR compared to thoracic SCI. However, there was no evidence of ventilatory long‐term facilitation following AIH in either group.
Document Details
- Document Type
- Pub Defense Publication
- Publication Date
- Sep 01, 2022
- Source ID
- 10.14814/phy2.15455
Entities
People
- Abdulghani Sankari
- Anan Salloum
- Harold Obiakor
- Hossein Yarandi
- M. Safwan Badr
- Mehdi Eshraghi
- Sarah Vaughan
- Sean Carroll
- Susmita Chowdhuri
Organizations
- National Heart, Lung, and Blood Institute
- United States Department of Defense
- United States Department of Veterans Affairs
- Veterans Health Administration
- Wayne State University