Goding G S
Department of Otolaryngology, University of Minnesota and Hennepin County Medical Center, Minneapolis 55415-1623, USA.
Laryngoscope. 1998 Jun;108(6):863-72. doi: 10.1097/00005537-199806000-00015.
To examine the relationship between the severity of the laryngeal chemoreflex (LCR) and the pattern of laryngeal muscle activity during an LCR-induced apnea.
The laryngeal mucosa of 20 piglets aged 17 to 20 days was stimulated under both hypoxic and normoxic conditions. Respiration, blood pressure, and activity of the thyroarytenoid (TA) and posterior cricoarytenoid (PCA) muscles were monitored during the LCR-induced apnea.
Hypoxemia resulted in a shorter average apnea duration but a greater degree of hypotension. All piglets recovered spontaneously following normoxic LCR stimulation. Hypoxic stimulation resulted in two divergent apneic responses: transient with a spontaneous recovery (17 piglets) or profound requiring resuscitation (three piglets). An increase in TA muscle activity and a decrease in PCA muscle activity was the most common response to LCR stimulation. The response of the TA and PCA muscles was maintained in piglets destined for spontaneous recovery. Decreasing TA activity and increasing PCA activity correlated with the development of a profound response.
The piglet demonstrates two distinct responses to hypoxic laryngeal chemostimulation that correlate with the activity of the intrinsic laryngeal muscles. Failure to maintain the activity of the TA and PCA muscles during a profound response is associated with the development of severe cardiovascular instability. This study suggests that the critical event involving the LCR is the development of complications secondary to hypoxia.
研究喉化学反射（LCR）的严重程度与LCR诱发呼吸暂停期间喉肌活动模式之间的关系。
在低氧和常氧条件下刺激20只17至20日龄仔猪的喉黏膜。在LCR诱发呼吸暂停期间监测呼吸、血压以及甲杓肌（TA）和环杓后肌（PCA）的活动。
低氧血症导致平均呼吸暂停持续时间缩短，但低血压程度加重。所有仔猪在常氧LCR刺激后均自发恢复。低氧刺激导致两种不同的呼吸暂停反应：短暂性且自发恢复（17只仔猪）或严重到需要复苏（3只仔猪）。TA肌活动增加和PCA肌活动减少是对LCR刺激最常见的反应。TA和PCA肌的反应在注定自发恢复的仔猪中持续存在。TA活动减少和PCA活动增加与严重反应的发展相关。
仔猪对低氧性喉化学刺激表现出两种不同的反应，这与喉内肌的活动相关。在严重反应期间未能维持TA和PCA肌的活动与严重心血管不稳定的发展有关。本研究表明，涉及LCR的关键事件是低氧继发并发症的发生。
