Role of Routine Preoperative Biochemistry in Anaesthesia

Objectives: To assess the value of routine preoperative biochemical tests and their effects on anaesthetic management.Design: A cross sectional study.Place and Duration of Study: Shalamar Hospital, Lahore. From August 1st 2009 to November 30th 2009.Methodology: We studied consecutive 500 ASA I and ASA II patients, 40 years of age and above, scheduled for elective surgery. Patients with any disease or factor that can lead to metabolic disturbance were ex-cluded from the study.Results: Patients were divided into 4 age groups, (Group A (40 - 49 years), Group B (50 - 59 years), Group C (60 - 69 years) and Group D (more than 70 years). Total abnormalities detected were 8 (1.6%). Abnormal blood sugar was found in 5 cases, 1.1% of all the tested patients, which belonged to age group A (1.7% of the group population). Abnormal blood urea was found in 2 cases which is 0.4% of the tested population and all of these belonged to age group D (2.8% of the age group population). Abnormal creatinine was found in one of the two cases of abnormal blood urea in the age group D, which is 0.2% of the tested population (1.4% of the group population). Serum electrolyte abnormalities were not found in any patient. The anaesthetic management was changed in 5 cases with abnormal blood sugar and was not influenced in patients with abnormal blood urea and serum creatinine.Conclusion and Recommendation: Routine preoperative serum electrolytes in patients, aged 40 - 70 years with no history of cardiac disease, renal disease and diabetes are not recommended. We recommend routine preoperative estimation of blood sugar in the all patients above the age of 40 years and renal function tests in patients above the age of 70 years