Usefulness of preoperative laboratory assessment of patients undergoing elective herniorrhaphy.

Preoperative laboratory utilization was evaluated in a retrospective review of 169 adults undergoing elective inguinal herniorrhaphy at a county/university hospital and at a private/community hospital. Tests monitored included a complete blood cell count, urinalysis, serum electrolytes, chest roentgenography, and electrocardiography. Abnormal results and results that altered the patients' treatment were sought. Two groups of patients were evaluated. Group 1 (n = 105) had no disease except for the inguinal hernia; group 2 (n = 64) had evidence of another disease process. Preoperative evaluation of patients in group 1 was similar at the county/university hospital and at the private/community hospital except for increased electrolyte screening at the county/university hospital among patients younger than age 40 years. No differences between hospitals were present among patients in group 2. Abnormal results not predicted by medical history or physical examination were found in 1% of patients in group 1 and 1.4% of patients in group 2. Only four patients (2%) had their treatment altered by these findings. Preoperative laboratory evaluation of these patients revealed that an abnormal test result not predicted by history and physical examination is rare. Routine preoperative laboratory testing is of little value in this patient population.