Acute normovolaemic haemodilution in colorectal surgery

Aims: Blood transfusions are often given to surgical patients. This study was designed to assess whether acute normovolaemic haemodilution (ANH) reduces exposure to allogeneic blood, affects clinical outcome and hospital stay, and is feasible in colorectal surgery. Methods: All ASA 1 and 11 patients undergoing colectomies performed between 1997 and 1999 were identified retrospectively from our colorectal cancer database to ascertain our current peri and postoperative transfusion practice. Twenty-six selected patients subsequently underwent ANH during colectomy surgery. The number of patients and units transfused were identified. Results: One hundred and twenty-three of 317 (39%) patients identified from our colorectal cancer database were transfused a total of 328 units (median 2, range 1–7). Of the 26 patients undergoing ANH, 4 (15%) were transfused a total of 13 units (median 3, range 2–5). The reduction in number of patients transfused was statistically significant (P=0.017). ANH increased anaesthetic time by a median of 19 min. There were no complications associated with ANH and the median hospital stay was 9 days (range 6–13). Conclusions: In this pilot study of selected patients, ANH is a feasible and effective method of reducing allogeneic blood exposure in major colorectal surgery. A prospective randomised controlled trial is now urgently required.