Analgesic effects of dyspnoea: 鈥淎ir hunger鈥?does not inhibit the spinal nociception reflex in humans

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• 作者：Capucine Mor茅lot-Panzini ; Julien Mayaux ; Fran莽ois Hug ; Jean-Claude Willer ; Thomas Similowski
• 关键词：Air hunger ; C-fibres ; Dyspnoea ; Pain ; Nociceptive flexor reflex
• 刊名：Respiratory Physiology & Neurobiology
• 出版年：1 January, 2014
• 年：2014
• 卷：190
• 期：Complete
• 页码：81-85
• 全文大小：800 K

文摘

Dyspnoea has distinct sensory modalities, including air hunger and the sensation of excessive breathing 鈥渨ork/effort鈥? Both have analgesic properties. In the case of work/effort, spinal mechanisms have been documented (inhibitory effect on the spinal nociceptive flexor reflex, RIII). This mechanism involves C-fibres. As C-fibres are unlikely to play a major role in air hunger, we hypothesised that inducing this type of dyspnoea would not result in RIII inhibition. Eight healthy volunteers were exposed to a hypercapnic hyperoxic gas mixture (5% CO₂ and 95% O₂) and asked to voluntarily fight the corresponding ventilatory reflex response by reducing tidal volume below its spontaneous level. Ventilatory variables and dyspnoea intensity (ordinal scale) were measured. Electromyography of the biceps femoris was used to record the amplitude of RIII in response to painful electrical sural nerve stimulation. Air hunger failed to inhibit the RIII reflex. We conclude that the mechanisms of air hunger induced analgesia do not include a spinal contribution and are therefore mostly central.