Background: The purpose of this study was to determine the most efficient preoperative laboratory screening for elective surgery.
Methods: Five hundred twenty patients undergoing elective operations on the general, vascular, thoracic, and head and neck surgical services were eligible for the study. The patient characteristics evaluated were age, gender, race, American Society of Anesthesiologists physical status classification, ponderal index, presence of concomitant respiratory disease, coronary artery disease, other heart disease, kidney disease, endocrine disease, malignancy, peripheral vascular disease, hypertension, diabetes mellitus, and neuropsychiatric disease. Preoperative laboratory screening included electrolytes, blood urea nitrogen, creatinine, and glucose levels, hemogram, nutritional studies (total protein and albumin levels and total lymphocyte count), coagulation studies (prothrombin time, partial thromboplastin time, and platelet count), urinalysis, electrocardiogram, and chest radiograph. Univariate analysis was done by Pearson's Chi square with Yate's correction. Significant p values were adjusted with Bonferroni's correction. Multivariate analysis was done with stepwise logistic regression.
Results: Univariate analysis showed age, gender, and the specific concomitant illness were associated with specific abnormal preoperative laboratory test results. Similarly, multivariate analysis showed specific predictors based on these risk factors.
Conclusions: Routine preoperative laboratory testing is neither useful nor cost-effective. Appropriate preoperative laboratory testing can be based on age, gender, concomitant medical diseases, and type of operation to be performed.