How cost effective are routine preoperative investigations?

Eight hundred and sixty patients were preassessed for elective varicose vein and inguinal hernia surgery at Wellington Hospital ion 1975 and 1976. Eight were refused operation on the grounds that they were unfit for general anaesthesia. Forty-nine went forward to operation with no investigations. The remaining 803 underwent a total of 1792 routine radiological and laboratory tests (chest x-ray, Coulter screen and ESR, plasma urea, creatinine and electrolytes). Abnormal test results were noted in 172 patients, 63 of these being unpredicted. Apart from one death (test results normal) there was no respiratory, renal or significant wound pathology. In no case did an unexpected abnormal result alter patient management. It is suggested that there is no justification for the routine preoperative laboratory investigation of asymptomatic and clinically normal patients who are undergoing elective minor surgery.