Influence of sleep states on laryngeal and abdominal muscle response to upper airway occlusion in lambs

• Published in: Pediatric research Vol. 41; no. 6; pp. 862 - 871
• Main Authors: KIANICKA, I, PRAUD, J.-P
• Format: Journal Article
• Language: English
• Published: Hagerstown, MD Lippincott Williams & Wilkins 01-06-1997
• Subjects: Abdominal Muscles - physiology; Abdominal Muscles - physiopathology; Anesthesia. Intensive care medicine. Transfusions. Cell therapy and gene therapy; Animals; Animals, Newborn; Arousal; Biological and medical sciences; Diaphragm - physiology; Electroencephalography; Electromyography; Emergency and intensive care: neonates and children. Prematurity. Sudden death; Inhalation - physiology; Intensive care medicine; Laryngeal Muscles - physiology; Laryngeal Muscles - physiopathology; Medical sciences; Sheep; Sleep Apnea Syndromes - physiopathology; Sleep Stages - physiology; Sleep, REM - physiology; Trachea - physiology; Wakefulness - physiology; Human; Occlusion; Sleep stage; Upper respiratory tract; Pathogenesis; Sudden death; Laryngeal muscle; Infant; Striated muscle; Abdomen; Vertebrata; Mammalia; Newborn animal; Sheep; Artiodactyla; Biological effect; Ungulata
• ISSN: 0031-3998; 1530-0447
• DOI: 10.1203/00006450-199706000-00011

This study was aimed at describing abdominal and laryngeal muscle responses to upper airway occlusion (UAO) in early life and the effect of sleep states on these responses. Twelve nonsedated, 9-26-d-old lambs were studied. We simultaneously recorded 1) airflow (pneumotachograph + face mask); 2) sleep states (electrocorticogram and electrooculogram); 3) abdominal muscle (external obliquus) electromyogram (EMG); and 4) glottic constrictor (thyroarytenoid) and dilator (posterior cricoarytenoid and cricothyroid) muscle EMGs. The pneumotachograph was repeatedly occluded for 15-30 s in wakefulness and natural sleep. We analyzed 90 occlusions during wakefulness (11 lambs), 28 during non-rapid eye movement (nREM) sleep (six lambs), and 23 during rapid eye movement (REM) sleep (five lambs). A phasic expiratory external obliquus EMG was present during baseline and progressively increased throughout UAO in wakefulness and nREM sleep, but not in REM sleep. Phasic thyroarytenoid EMG progressively increased during inspiratory efforts throughout UAO in wakefulness and nREM sleep, paralleling the increase in glottic dilator (posterior cricoarytenoid and cricothyroid) EMG. In contrast, glottic muscle response to UAO in REM sleep was severely blunted or disorganized by frequent swallowing movements. We conclude that UAO triggers complex and coordinated laryngeal and abdominal muscle responses during wakefulness and nREM sleep in lambs; these responses are largely absent, however, in REM sleep. These unique results, together with the defective arousal response in REM sleep, suggest that vulnerability to airway occlusion could be increased during REM sleep in early life. Possible implications for understanding severe postnatal apneas are discussed.