Prophylaxis in elective colorectal surgery: the cost of ignoring the evidence

Introduction: Three strategies are used to prevent complications in colorectal surgery: heparin and antibiotics given perioperatively and abdominal drains placed intraoperatively. To investigate the appropriate and inappropriate use of these prophylactic techniques and to assess the costs associated with their inappropriate use, we studied patients who underwent elective colorectal procedures. Methods: We reviewed the charts of 103 patients operated on between April and December 1999 at a 519-bed tertiary care, reaching hospital in Edmonton, Alta. The procedures carried out were elective sigmoid resection, low anterior resection, left hemicolectomy, right hemicolectomy and total or subtotal colectomy for benign or malignant conditions. The data collected included patient age and sex, diagnosis, the operating surgeon, and the housestaff or surgeon writing the pre- and postoperative orders. Patients who required emergency colorectal surgery were excluded from the study. Antibiotic, heparin and drain prophylaxis was assessed and considered appropriate if prescribed according to the evidence or inappropriate if prescribed when not recommended. Results: Thirty-six of 98 patients had inappropriate heparin prophylaxis (5 of the 103 were excluded because they were already receiving heparin). Only 5 of 96 patients were treated appropriately with antibiotics preoperatively without postoperative doses (7 of the 103 were excluded due to intraoperative spillage with fecal contamination or an intra-abdominal abscess found intraoperatively); 95% of patients were inappropriately treated with antibiotics postoperatively. Half of all the patients had a drain inserted inappropriately for prophylaxis. On average, drains inserted inappropriately cost $30.40 per patient, inappropriate antibiotic use cost $62.42 per patient and inappropriate heparin use cost $89.30 per patient. Preoperative orders were usually written by the staff surgeon, whereas postoperative orders were usually written by the resident or intern. Conclusions: We observed considerable inappropriate use of heparin, antibiotic and drain prophylaxis. Considering the number of elective colorectal procedures performed annually, these inappropriately used strategies represent a substantial cost to the health care system. Improved education of surgeons and residents is needed to change to evidence-based practice habits.