ESA Best Abstract Prize Competition (BAPC)
Background and Goal of Study: Postoperative shivering (PAS) is uncomfortable for patients and potentially risky (1). The aim of this observational trial was to identify independent risk factors for PAS after general anaesthesia (2).
Materials and Methods: The study was approved by the local ethics committee. Potential risk factors for PAS were recorded in 1,340 consecutive patients. Signs of shivering, peripheral and core temperature, and thermal comfort were recorded in the postanaesthetic care unit. The data were split into an evaluation dataset (n = 1000) and a validation (n = 340) dataset. The first was used to identify independent risk factors for PAS and to formulate a risk score using backward-elimination logistic regression analysis. The proposed model was subsequently tested for its discrimination and calibration properties using ROC-curve analysis and linear correlation between the predicted and the actual incidences of PAS in the validation group.
Results and Discussions: The incidence of PAS was 11.6%. There were three major risk factors: young age, endoprothetic surgery, and core hypothermia - with age being the most important. The risk score derived from this analysis had a reasonable discriminating power, with an area under the ROC-curve of 0.69 (95%-CI: 0.60-0.78; P < 0.0001). Furthermore the equation of the calibration curve (y = 0.69x + 6; R2 = 0.82; P < 0.05) indicated a good and statistically significant agreement between predicted and actual PAS incidence.
Conclusion: Postoperative shivering can be predicted with acceptable accuracy using the four risk factors identified in the present study. The presented model may serve as a clinical tool to help clinicians to rationally administer prophylactic anti-shivering drugs.
1 Buggy DJ, Crossley AW. Thermoregulation, mild perioperative hypothermia and postanaesthetic shivering. Br J Anaesth 2000;84:615-28.
2 Crossley AW. Six months of shivering in a district general hospital. Anaesthesia 1992;47:845-8.