Introduction
Shivering is a relatively common problem encountered during the perioperative period. It is reported in 40 to 70% of patients undergoing surgery under regional anesthesia[1].
Along with nausea and vomiting, postanesthesia shivering is one of the leading causes of discomfort for patients. Shivering not only adds psychological stress to the patient but also physiologically leads to an increase in O2 consumption by 200-500%, and increased carbon dioxide production which may lead to problems in patients with existing intrapulmonary shunts, fixed cardiac output, or limited respiratory reserve[1].
The primary cause of postanasthesia shivering is perioperative hypothermia. However, shivering associated with cutaneous vasodilatation (non-thermoregulatory shivering) also occurs [2]. As shivering has been reported in normothermic patients, other mechanisms such as inhibited spinal reflexes, apprehension, decreased sympathetic activity, pyrogen release, adrenal gland suppression, and respiratory alkalosis have been suggested [3].
Kranke et al.[4]extrapolated data from a meta-analysis regarding medications and dosing practices and concluded that prophylaxis against …show more content…
Dexmedetomidine and meperidine are both central α2-receptor agonists. Dexmedetomidine and meperidine additively reduced the shivering threshold in healthy adults by ≈2°C, with only minimal sedation or respiratory toxicity [11]. Dexmedetomidine comparably reduces the vasoconstriction and shivering thresholds, thus suggesting that it acts on the central thermoregulatory system rather than preventing shivering peripherally[12]. It also acts by blocking α2 receptors at the locus ceruleus of the brainstem and spinal cord thus causing sedation and analgesia