Hi:
I've heard that extreme pain causes neurogenic shock by overexciting the parasympathetic nervous system. This causes the heart rate to slow too much leading to a dangerous drop in blood pressure and, hence, shock -- maybe even death.
Does severe pain cause this type of shock?
Thanks,
Green Xenon
Pain stimulates the autonomic nervous system, both sympathetic and parasympathetic. Normally in adults, sympathetic stimulation dominates, hence, we commonly encounter tachycardia and hypertension in response to pain
In paediatric age group or in adults with autonomic dysfunction, catecholamine depleted state or vagal hyperactivity, the same stimulus may produce a response that is dominated by parasympathetic stimulation and hence may lead to symptoms of parasympathetic stimulation like bradycardia, asystole, bronchospasm and laryngospasm.
Typical examples of this parasympathetic activation includes some common reflexes encountered during anaesthesia like the Brewer-Luckardt reflex, Bezold-Jarisch reflex and the ventricular mass reflexes that produce cardiac arrest in oterwise healthy young adults during spinal anaesthesia
Regs