Introduction: The American Society of Anesthesiologists (ASA) grade is supposed to accurately predict morbidity and mortality. We wanted to better inform our patients of their risk of mortality in elective operations.

Method: Analysis of data from Galen (Theatre management software) routinely gathered as part of the preoperative assessment of patients. We linked this to the Date of Death field in the Hospital Master Patient index to identify those patients who had died within 90 days of surgery, including deaths after discharge from hospital.

Results: Two thousand and thirty one patients over two years. These were elective Orthopaedic operations including knee (1074) and hip (957) replacements, both primary and revision. There were thirty one mortalities over a two year period. Sixteen mortalities for knee (1.5% of knee operations) and 15 for hip surgery (1.6% of hip operations). Respective mortality for ASA grades 1–4 are presented in table below

Discussion: Our review of the 2031 patients shows that the relative risk of mortality between ASA grades 1–4 increased from 1–8.8. We examined the notes because grade 4’s mortality was 10% and realized that 75% of ASA grades recorded by Orthopaedic surgeons and anaesthetists differed. The anaesthetists seem to down grade the ASA 4’s.

Conclusion: The relative risk of mortality is lower than that as previously described. Orthopaedic surgeons seem to assess patient better when it comes to ASA grading. The paper further discusses the implications of these conclusions.