Postanesthetic shivering explained

Postanesthetic shivering
Field:	Anesthesia

Postanesthetic shivering (PAS) is shivering after anesthesia.^[1]

Description and treatment

Postanesthetic shivering is one of the leading causes of discomfort in patients recovering from general anesthesia. It usually results due to the anesthetic inhibiting the body's thermoregulatory capability, although cutaneous vasodilation (triggered by post-operative pain) may also be a causative factor. First-line treatment consists of warming the patient; more persistent/severe cases may be treated with medications such as tramadol, pethidine, clonidine, and nefopam, which work by reducing the shivering threshold temperature and reducing the patient's level of discomfort. As these medications may react and/or synergize with the anesthetic agents employed during the surgery, their use is generally avoided when possible.^[2] The anesthetic ketamine can also be used to manage postanesthetic shivering.^[3]

Intensity

The intensity of PAS may be graded using the scale described by Crossley and Mahajan:

0 = no shivering;

1 = no visible muscle activity but piloerection, peripheral vasoconstriction, or both are present (other causes excluded);

2 = muscular activity in only one muscle group;

3 = moderate muscular activity in more than one muscle group but no generalized shaking;

4 = violent muscular activity that involves the whole body.

Further reading

• Crossley AW, Mahajan RP . The intensity of postoperative shivering is unrelated to axillary temperature . Anaesthesia . 49 . 3 . 205–7 . March 1994 . 8147511 . 10.1111/j.1365-2044.1994.tb03422.x. 205247789 .
• Buggy DJ, Crossley AW . Thermoregulation, mild perioperative hypothermia and postanaesthetic shivering . Br J Anaesth . 84 . 5 . 615–28 . May 2000 . 10844839 . 10.1093/bja/84.5.615. free .
• Alfonsi P . Postanaesthetic shivering. Epidemiology, pathophysiology and approaches to prevention and management . Minerva Anestesiol . 69 . 5 . 438–42 . May 2003 . 12768180 .
• Kranke P, Eberhart LH, Roewer N, Tramèr MR . Peter Kranke . Pharmacological treatment of postoperative shivering: a quantitative systematic review of randomized controlled trials . Anesth. Analg. . 94 . 2 . 453–60 . February 2002 . 11812718 . 10.1213/00000539-200202000-00043. 12094935 . free .
• Kranke P, Eberhart LH, Roewer N, Tramèr MR . Peter Kranke . Single-dose parenteral pharmacological interventions for the prevention of postoperative shivering: a quantitative systematic review of randomized controlled trials . Anesth. Analg. . 99 . 3 . 718–27 . September 2004 . 15333401 . 10.1213/01.ANE.0000130589.00098.CD . 35191305 . free .
• Eberhart LH, Döderlein F, Eisenhardt G, etal . Independent risk factors for postoperative shivering . Anesth. Analg. . 101 . 6 . 1849–57 . December 2005 . 16301273 . 10.1213/01.ANE.0000184128.41795.FE . 5752644 . free .

Notes and References

1. English W. Post-operative shivering, causes, prevention and treatment (letter). Update in Anaesthesia. 1. 3. 2002. 8 September 2010. dead. https://web.archive.org/web/20110529013054/http://www.nda.ox.ac.uk/wfsa/html/u15/u1503_01.htm. 29 May 2011.
2. Postanaesthetic shivering: epidemiology, pathophysiology, and approaches to prevention and management.. Alfonsi, P. 11772130 . 61. 15. 2001. Drugs. 2193–205. 10.2165/00003495-200161150-00004. 46962855 .
3. Zhou . Y . Mannan . A . Han . Y . Liu . H . Guan . HL . Gao . X . Dai . MS . Cao . JL . Efficacy and safety of prophylactic use of ketamine for prevention of postanesthetic shivering: a systematic review and meta analysis. . BMC Anesthesiology . 30 December 2019 . 19 . 1 . 245 . 10.1186/s12871-019-0910-8 . 31888509 . 6937868 . free .