Скачать или смотреть WHY DOES REMIFENTANIL WITHDRAWAL CAUSE SHIVERING?

When a person undergoes surgery involving remifentanil, a short-acting opioid, they may experience shivering (post-anesthetic shivering or PAS) upon its discontinuation.
Here's why:
Rapid Opioid Withdrawal and Acute Tolerance: Remifentanil is eliminated quickly from the body. Prolonged use, especially at higher doses, can lead to the development of acute opioid tolerance. This means the body becomes accustomed to the presence of the drug. When the drug is suddenly withdrawn, the body undergoes a rapid withdrawal process, which can trigger shivering as a symptom.
NMDA Receptor Activation: Research suggests that acute opioid tolerance and the associated shivering may be linked to the activation of N-methyl-D-aspartate (NMDA) receptors in the brain. These receptors play a crucial role in the development of hyperalgesia (increased sensitivity to pain), a phenomenon that can also occur after high-dose remifentanil administration.
Not Primarily Due to Hypothermia or Pain: Studies have shown that remifentanil-induced shivering doesn't appear to be primarily caused by intraoperative hypothermia (low body temperature during surgery) or postoperative pain. Although low body temperature can contribute to shivering in general, research indicates that the incidence of shivering with remifentanil doesn't correlate directly with body temperature changes. Similarly, even with adequate pain control, patients may still experience shivering after remifentanil discontinuation, suggesting pain isn't the primary driver.
In essence, the body's rapid adjustment to the sudden absence of remifentanil and the subsequent neurochemical changes, particularly involving NMDA receptors, are thought to be the key reasons behind the shivering experienced during remifentanil withdrawal.