A reduction in Type and Screen: preoperative prediction of RBC transfusions in surgery procedures with intermediate transfusion risks †

Abstract

In many patients, a 'type and screen' procedure is routinely performed before surgery. However, most patients are not transfused after all. Can we predict, which surgical patients will and will not be transfused, to reduce the number of these investigations? We studied 1482 consecutive surgical patients with intermediate risk for transfusion. Multivariate logistic regression modelling and the area under the Receiver Operating Characteristic curve (ROC area) were used to quantify how well age, gender, surgical procedure, emergency or elective surgery and anaesthetic technique predicted transfusion, and whether the preoperative haemoglobin concentration had added predictive value. Gender, age > or =70 yr, and type of surgery were independent predictors of transfusion, with a ROC area of 0.75 (95% CI: 0.72-0.79). Validating this model with an easily used prediction rule in a second patient population yielded a ROC area of 0.70 (95% CI: 0.63-0.77). With this rule type and screen could correctly be withheld in 35% of these patients. In the remaining 65% of the patients, a further reduction in type and screen investigations of 15% could be achieved using the preoperative haemoglobin concentration. Using a simple prediction rule, preoperative type and screen investigations in patients who have to undergo surgery procedures with intermediate transfusion risk can be avoided in about 50%. This may reduce patient burden and hospital costs (on average: 3 million US$ per 100 000 procedures).

Bleeding impacting mortality after noncardiac surgery: a protocol to establish diagnostic criteria, estimate prognostic importance, and develop and validate a prediction guide in an international prospective cohort study

“…24 These data suggest that a perioperative bleeding event should not increase the risk of death unless the hemoglobin level goes below 80 g/L or perhaps 70 g/L. Finally, numerous investiga- tors have attempted to predict bleeding requiring perioperative blood transfusion in noncardiac surgery, [25][26][27][28][29][30][31] but those studies were small compared to our study, with samples ranging from 94 to 1875 patients, and were often limited to a single centre and type of surgery.…”

Systematic Criteria for Type and Screen Based on Procedure's Probability of Erythrocyte Transfusion

“…This example shows that a threshold of 10.0% would not match clinician decision-making, whereas a threshold of 5.0% would match decisions. The choice of 5.0% matches the criterion from van Klei et al 8,9 A criterion based on an incidence of transfusion (e.g., 5.0% or more) differs from one based on the mean units transfused for each procedure (i.e., the "transfusion index"). 4 -6,23,24 One of our objectives was to interpret use of the mean units transfused.…”

“…van Klei et al previously suggested that type and screen be performed for procedures with 5% or more incidence of transfusion with one or more units. 8,9 They showed that the criterion was suitable for multiple facilities, but studied only a few procedures, all with large numbers of cases. 8,9 Consider the decision whether to type and screen for "unilateral total hip replacement."…”

“…8,9 They showed that the criterion was suitable for multiple facilities, but studied only a few procedures, all with large numbers of cases. 8,9 Consider the decision whether to type and screen for "unilateral total hip replacement." The procedure had a transfusion rate of 7.8% (n ϭ 393/5,064).…”

“…[7][8][9] van Klei et al showed that not using type and screen preoperatively for procedures with the rate of transfusion less than 5% was suitable for cholecystectomy at multiple facilities. 8,9 We therefore examined the relationship between this standard of "5% probability of transfusion" and the median EBL of procedures. We hypothesized that for most procedures with relatively small sample sizes (e.g., fewer than 163 cases)**, 10 -16 the historical estimated median EBL could be used to forecast whether the risk of transfusion is less than the 5% criterion.…”