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SummaryThe relationship between axillary temperature and postoperative shivering was examined in 302 patients who entered one recovery room in the Derbyshire Royal Infirmary over a one-month period. No relationship was found between temperature and the occurrence of shivering, or between conscious level and the occurrence of shivering. Key wordsTemperature; body, regulation. Complications; shivering.Postoperative shivering is distressing for the patient and may impair the quality of recovery from anaesthesia by increasing oxygen consumption and thereby causing hypoxaemia and lactic acidosis [1-4]. It has been noted repeatedly that shivering after general anaesthesia correlates poorly with body temperature although Vaughan and colleagues [8] reported that patients who entered the recovery room with an axillary temperature less than 36°C shivered for longer than those who were warmer. In a previous study [lo], we were unable to confirm these reports because of the study design.In most studies, there has been little attempt to standardise the classification of postoperative shivering, and this omission has led to difficulty in the interpretation of otherwise comparable investigations. We have devised a simple clinical grading scale for postoperative shivering which we have applied to patients recovering from general anaesthesia. The results reported here are derived from a larger study of recovery parameters which will be reported separately. MethodsData relating to various parameters relevant to recovery from general anaesthesia were collected from 302 patients over a one-month period. The data were collected by the recovery room nurses on entry of the patient into the recovery room, after 15 min, and again 30 min after entry, and included grade of shivering (Table 1) and axillary temperature measured using a mercury-in-glass clinical thermometer. Conscious level (Table 2), pain score, nausea and vomiting and various ventilatory and cardiovascular parameters were also recorded.The data were combined with information about anaesthetic technique collected using the Derby Anaesthetic Audit System [ll]. Statistical analysis was by paired Student's t-test, analysis of variance, Mann-Whitney U test and the Chi-squared test where appropriate, and was performed using the SPSS-PC+ statistical package. A probability of p < 0.05 was taken as indicating statistical significance.

SummaryThis study was designed to find the minimum effective doses of doxapram and pethidine to stop post-anaesthetic shivering. Two hundred and twenty healthy patients who shivered following routine surgery were allocated randomly to receive one of 10 doses of doxapram (0.18, 0.23, 0.29, 0.35, 0.41, 0.47, 0.7, 0.93

We have compared the effects of pethidine, alfentanil and placebo in the treatment of post-anaesthetic shivering. Ninety patients who shivered after routine surgery were allocated randomly to receive normal saline (n = 30), alfentanil 250 micrograms (n = 30) or pethidine 25 mg (n = 30). After 10 min, 26 patients had stopped shivering in the pethidine group which was significantly more than the incidence in the two other groups (placebo = 7; alfentanil = 12) (P < 0.0002). Alfentanil was not significantly different from normal saline in affecting shivering. We conclude that alfentanil 250 micrograms was not effective in the treatment of post-anaesthetic shivering.

SummaryOf 2595 patients admitted to a recovery room in Derbyshire Royal Infirmary over a 6-month period, 164 (6.3%) shivered postoperatively. Data regarding the anaesthetic techniques to which these patients had been subjected were gathered from the Derby Anaesthetic Audit System. Subsequent analysis demonstrated the importance of a number of factors that led to shivering, including male gender, anaesthetic techniques involving spontaneous ventilation. and anticholinergic premedication. The administration of pethidine. alfentanil or morphine intra-operatively reduced the incidence of shivering postoperatively.