All except one are true about post-neuraxial anaesthesia shivering
**Core Concept**
Post-neuraxial anaesthesia shivering is a common complication that occurs after regional anaesthesia, such as epidural or spinal anaesthesia. It is characterized by involuntary muscle contractions, leading to a rise in body temperature. The exact mechanisms behind post-neuraxial shivering are not fully understood, but it is thought to be related to the sympathetic nervous system's response to the anaesthesia.
**Why the Correct Answer is Right**
Shivering after post-neuraxial anaesthesia is often caused by the release of vasoconstrictors, such as norepinephrine, from the sympathetic nervous system. This leads to an increase in peripheral vascular resistance, which in turn causes an increase in body temperature. Additionally, the release of thyroid-stimulating hormone (TSH) and the activation of the hypothalamic-pituitary-thyroid axis may also contribute to the development of shivering. Furthermore, the anaesthetic agents themselves, such as local anaesthetics and opioids, may also play a role in the development of shivering.
**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because it is not a true statement about post-neuraxial shivering. Shivering is not caused by a direct effect on the hypothalamus.
**Option B:** This option is incorrect because it is not a true statement about post-neuraxial shivering. The sympathetic nervous system's response to anaesthesia is the primary cause of shivering, not the parasympathetic nervous system.
**Option C:** This option is incorrect because it is not a true statement about post-neuraxial shivering. While hypothermia is a risk factor for shivering, it is not the primary cause of post-neuraxial shivering.
**Option D:** This option is incorrect because it is not a true statement about post-neuraxial shivering. The use of vasopressors is not a direct cause of shivering after post-neuraxial anaesthesia.
**Clinical Pearl / High-Yield Fact**
Post-neuraxial shivering can be prevented or treated with the use of pharmacological agents, such as clonidine and meperidine, which can help to reduce the release of vasoconstrictors and the activation of the sympathetic nervous system.
**Correct Answer: C. Hypothermia is a risk factor for shivering, but it is not the primary cause of post-neuraxial shivering.**