Assessment of routine pre-operative group and save testing in patients undergoing cholecystectomy: a retrospective cohort study

Abstract

Background Routine group and save (G&S) testing is frequently performed prior to cholecystectomy, despite growing evidence that a targeted approach is safe and avoids unnecessary investigations. This retrospective cohort study explored frequency of testing in our unit, and rates of and independent pre-operative risk factors for peri-operative blood transfusion. Methods Health records of 453 consecutive adults who underwent cholecystectomy in a UK NHS trust were reviewed for blood transfusion up to 30 days post-operatively. We compared the need for transfusion against patient demographics, indication and urgency of surgery, and the number of prior emergency hospital attendances with gallstone complications. Logistic regression determined whether prior attendances with complications of gallstones independently predicted the need for transfusion. Results Peri-operative blood transfusions within 30 days of operation occurred in 1.1% of cases, with no requirement for uncrossmatched blood. Patients who received a blood transfusion tended to have higher American Society of Anesthesiologists (ASA) grades (p<0.001), were more likely to have an underlying primary haematological malignancy (20.0% vs. 0.2%; p<0.001) and prior emergency hospital attendances with gallstone complications (median 4 vs. 1; p<0.001). Logistic regression showed each prior emergency attendance was associated with 4.6-fold odds of transfusion (p=0.019). Receiver operating characteristic curve analysis showed an area under the curve of 0.92. Three or more attendances predicted need for transfusion with 60.0% sensitivity and 98.0% specificity. Seventy-four percent had at least one G&S sample taken pre-operatively, costing the trust approximately £3,800 per year in materials. Conclusions Pre-operative G&S testing prior to cholecystectomy may not be routinely required. Increased frequency of prior emergency hospital attendances with gallstone complications and co-morbidities associated with coagulopathies were pre-operative risk factors for post-operative blood transfusion. More selective testing could provide large financial savings for health institutions without compromising patient safety.