Incidence, severity and factors lead to abnormal pre-operative blood chemistry, CBC, Chest X-ray and EKG in routine preoperative investigation

Abstract

Backgrounds: Nowaday, the routine preoperative testing which were established as the standard guideline in Siriraj Hospital may be less needed because of very low positive results and costly.

Objectives: To evaluate the incidence, severity and factors contribute to abnormal preoperative complete blood count (CBC), blood chemistry, chest x-ray (CXR), and electrocardiogram (EKG) undergoing non-cardiac or non- neurological surgery. Methods: This cross-sectional study was conducted in Siriraj Hospital. The electronic data was retrieved from December 2013 to June 2015. Incidence and severities of abnormal test were analyzed. Studied risk factors (gender, age, ASA classification, underlying disease, emergency operation, size of operation) were analyzed for correlation to each test. Factors contributed to abnormal results in significant of p<0.001 were further analyzed in logistic regression. Results: 6280 patients were enrolled in this study. Nearly 100% of patients was ordered for hematocrit preoperatively. Others tests were perform in 70-80% of all patients. The incidence of abnormal results were EKG (19.5%), CXR (15.7%), UA (3.8%), Hb (38.5%), Hct (45%), BS (51.7%), BUN (21.8%), Cr (41%), Na (12%), K (11.2%), Cl (18%), HCO3 (19%).  The older age and ASA > 1 were significantly related to incidence and severity of abnormal preoperative testing (p<0.001). In a logistic regression analysis, age ≥ 45years old, ASA ≥ 2, HT, DM, IHD were associated with abnormal preoperative EKG. Age ≥45 years old, ASA ≥ 2 and underlying disease. Conclusions: ASA 1 and age less than 45 years old patients undergoing non-cardiac or non- neurological surgery were not necessary to have any preoperative testing.  EKG was recommend in patient aged >60 years old or with indication. Urinalysis and blood chemistry should be order only by individual indication.