Introduction and Aim In the intraoperative or postoperative period of hip replacement surgeries, approximately 46% of patients receive erythrocyte transfusion. 'Patient blood management' protocols have been established in order to reduce the frequency of perioperative surgical bleeding and transfusion. The aim of this study is to evaluate the patients who underwent hip replacement by the same experienced surgeon; to evaluate retrospectively in terms of patient characteristics, surgical and anesthesia management, blood transfusion frequency.

Methods The characteristics of patients who underwent hip replacement (total hip replacement, revision hip replacement, partial hip replacement) operation by the same experienced surgeon between 2010-2022 at Baskent University after the approval of Baskent University Medical and Health Sciences Research Board, results will be analyzed retrospectively through perioperative follow-up forms and review of patient files.

Expectations and scientific contributions Preparing patients for surgery, determining the causes of blood loss during and after surgery and creating preventive strategies are important for all operations, especially hip replacement surgeries. While determining the strategies, the main aim should be to see the pre-, intra- and post-operative period as a whole, to determine the transfusion risks according to the comorbidities and anemia of the patients, and to determine the anesthesia and analgesia managements that reduce blood loss in the intraoperative and postoperative periods.

Introduction and Aim Hip replacement surgeries are among the operations whose frequency is increasing in our country and in the world. In these operations, procedures such as soft tissue dissection, exposing the hypervascular metaphysis and bone resection cause acute blood loss and continue in the form of leakage in the postoperative period. It has been reported that the rate of blood transfusion in hip operations in the United States is between 18-68%. There are studies reporting that erythrocyte transfusion rate approximately 46% of these cases in the intraoperative or postoperative period. Various complications may develop in patients during or after blood transfusion. These complications include local or systemic infections, venous thromboembolic events, allergic reactions, circulatory overload, transfusion-induced acute lung injury, morbidity, mortality, and increased hospital stay. In addition, a significant increase in cost can be seen. It is thought that the amount of bleeding varies according to the duration of the operation, the experience of the surgeon, and the type of surgery. Therefore, it is important for patient safety to reduce surgical bleeding and avoid transfusion applications as much as possible.

"Patient blood management" has been defined as, to reduce the frequency of perioperative surgical bleeding and transfusion. Perioperative patient blood management practices, correction of preoperative anemia, autologous blood donation, discontinuation of blood thinners, acute normovolemic hemodilution, use of tranexamic acid, regional anesthesia, controlled hypotension, avoidance of hypothermia, appropriate fluid management, meticulous surgery, appropriate hemostasis, patient position, postoperative drain strategy. 'Patient blood management' measures are actively applied in hip replacement surgeries, which are one of the major orthopedic surgeries.

The aim of this study is to evaluate the patients who underwent hip replacement by the same experienced surgeon in this center; to evaluate retrospectively in terms of patient characteristics, surgical and anesthesia management, blood transfusion frequency.

Methods The characteristics of patients who underwent hip replacement (total hip replacement, revision hip replacement, partial hip replacement) operation by the same experienced surgeon between 2010-2022 at Baskent University after the approval of Baskent University Medical and Health Sciences Research Board, It will be analyzed retrospectively through perioperative follow-up forms and review of patient files.

From preoperative records; Demographic data (Age, sex, height, body weight), diagnoses (Hip arthrosis, hip revision, hip fracture, congenital hip dislocation, infected hip replacement revision), American Society of Anesthesiologists Physical Condition Classification (ASA), co-morbidities (Hypertension, diabetes, chronic kidney failure, hepatopathy, inflammatory disease), smoking, alcohol, antiplatelet/anticoagulant, nonsteroidal anti-inflammatory use (NSAII), opioid, herbal medicine use, antiplatelet cut-off time compliance, hemoglobin (Hb), hematocrit (Htc), leukocytes, thrombocyte, activated partial thromboplastin time (APTT), prothrombin time (PTZ), international normalized ratio (INR), preoperative erythrocyte (ES) transfusion/amount.

From intraoperative records; Year of operation, mallampati score, type of operation, duration of operation, whether emergency or elective, duration of anesthesia, type of anesthesia, intraoperative blood pressure (systolic and diastolic), heart rate, peripheral oxygen saturation, amount/type of fluid administered, ES transfusion/ amount, Hb when transfused, drugs used for anesthesia and analgesia and their amount, amount of blood in the aspirator, administration of tranexamic acid, amount of intraoperative urine.

From the postoperative records; Hb/Htc values, ES transfusion/amount/day of administration, use of drain, amount of blood in the drain, amount of postoperative urine, intensive care unit admission, initiation of anticoagulants, early and late complications (Atrial fibrillation, pneumonia , renal failure, prosthesis infection, allergic reactions, nausea-vomiting), postoperative analgesia (Epidural/intravenous patient-controlled analgesia, opioid and NSAID use), Hb, urea, creatinine values at postoperative 6th and 12th hours and at discharge, iron preparation use, The number of hospitalization days and the mortality within 7 days will be recorded and the data will be compared.

Statistical analysis Statistical analysis will be performed using SPSS (SPSS Inc. Chicago, Illinois, USA) version 20.0 of the statistical program. Descriptive statistical methods (frequency, percentage, mean, standard deviation) will be used while evaluating the study data. The Kolmogorov-Smirnov test will be used to evaluate the conformity of the data of the patients with and without ES transfusion to normal distribution. T-test will be used in the analysis of data suitable for normal distribution, Kruskal-Wallis test or Mann Whitney U test will be used in the analysis of data not suitable for normal distribution. X² will be used in the analysis of qualitative or counted data. p<0.05 will be considered significant.

Expectations and scientific contributions Preparing patients for surgery, determining the causes of blood loss during and after surgery and creating preventive strategies are important for all operations, especially hip replacement surgeries. While determining the strategies, the main aim should be to see the pre-, intra- and post-operative period as a whole, to determine the transfusion risks according to the comorbidities and anemia of the patients, and to determine the anesthesia and analgesia managements that reduce blood loss in the intraoperative and postoperative periods. With this study, it is aimed to both update the practice and contribute to the literature by examining the operations performed by the same experienced surgeon and testing the effectiveness and safety of the strategies applied.

Inclusion Criteria:

• Patients who have undergone hip replacement by the same experienced surgeon in the last 12 years

Exclusion Criteria:

• Patients with insufficient data will be excluded from the study.

Patients who have undergone hip replacement by the same experienced surgeon in the last 12 years will be retrospectively screened from patient files and the system in terms of anesthesia and blood transfusion applications.