Anales de la RANM

74 A N A L E S R A N M R E V I S T A F U N D A D A E N 1 8 7 9 POSTOPERATIVE BLOOD SALVAGE AFTER KNEE ARTHROPLASTY Valbuena I, et al. An RANM. 2022;139(01): 67 - 77 In this retrospective observational study, we observed that BS strategies are an effective tool to achieve a significant reduction in ABT, and this is consistent with most published studies (table 4). Muñoz et al. a lso found a reduction in the number of blood units transfused (11). We couldn’t confirm this reduction in our study because the sample size was not calculated for this variable. However, other authors like So-Osman el al. (12) did not either find any difference in transfusion rate, but their patients presented preoperative hemoglobin levels superior to 13 g/dl. No difference was found either by Martin y von Strempel, Abuzakuk et al. (13) , Tomasen et al. (14) and Cip et al. (15) whose patients presented any rank of Hb. Nevertheless, Tomasen’s study was performed in patients who were optimized preoperatively with a restrictive transfusion program. They received pre- and postoperative EPO treatment. This explains the very low transfusion rate (7.1%) hiding the positive effect of BS on ABT (15). Patients with BS had higher Hemoglobin and Hemato- crit values than those without BS during their whole hospital stay. They presented a decrease of Hb and Hematocrit at 48 hours and recovered on the fifth day. This trend is similar to the one described by Zhou et al. (16) and Mayer-Rollnik (17). Kourtzis et al. (12) , Sinclair et al. (13) , Kirkos et al. (18) y Biarnés et al. (19) also demonstrated the efficacy of BS in maintai- ning higher postoperative Hb and Htc values. Moonen et al . (10) and Tomasen et al. (15) described higher albeit non significative differences in the postope- rative Hb values in the BS group. Our population’s clinical and demographic characteristics were similar to other studies about TKA and total knee replace- ment (10,12,13,19,20,21). The transfusion rate in our study was lower than that of other series. Gombotz et al. showed (22) is a wide variability between 20 and 50% (23.9% presented preoperative anaemia, Hb < 13 g/dl) was similar to those of Saleh E. et al. (4) (19.96%), Hare et al. (23) (20%) and those estimated by WHO for the world (25%) and Europe (28.7%) (24,25). However, patients in the study of Saleh E. et al. (26) presented more severe anaemia than those in our study. This high prevalence of preoperative anaemia might be due to a higher incidence of rheumatoid arthritis in their cohort of patients. This inflammatory disease is often accompanied by anaemia and the risk of ABT is increased three-fold (27,28). The progressively aging population increases the need for arthroplasty. Associated comorbidity, mainly cardiovascular pathology, increases the need for anti-platelet and anticoagulant therapy. Very few studies address the issue of the influence of APT and anticoagulant therapy on orthopaedic surgery bleeding. We identified APT and LMWHT as the most important risk factors for bleeding and ABT as in Burger et al. (29) studied this outcome in a meta-analysis, as well as did the authors of the POISE-2 clinical trial (Perioperative Ischemia Figure 4. Transfusion rate depending on ASA Classification. ABT: Allogenic blood transfusion; ASA: American Society of Anesthesiologists Classification. Chi-square Test, p=0,032 DISCUSSION