Preoperative Optimisation in Vascular Patients to Reduce Peri- and Postoperative Blood Transfusions and Postoperative Complications – A Proof of Concept Study

Abstract

Introduction: Preoperative anaemia is associated with an increased risk of peri- and postoperative morbidity and mortality. Additionally, preoperative anaemia increases Red Blood Cell (RBC) transfusions associated with postoperative complications and an increase in the risk of perioperative myocardial damage. Perioperative myocardial damage is associated with increased morbidity and mortality. Preoperative screening of vascular patients for anaemia and structural heart disease facilitates optimisation of haemoglobin prior to surgery and enables, patient-tailored anaesthesia. This may increase perioperative oxygen delivery and reduce RBC transfusions. We aimed to investigate the effects of preoperative treatment of iron-deficiency anaemia on red blood cell (RBC) transfusions and postoperative myocardial damage, as well as the effect of preoperative screening for unknown heart disease with a focused cardiac ultrasound (FOCUS) in a vascular surgery patient cohort. Methods: This study was performed as an observational intervention study with a three-months observation period followed by a three-months intervention period. In the intervention period iron-deficient, anaemic patients received intravenous iron at the outpatient clinic, and all patients underwent a FOCUS scan in the outpatient clinic before surgery. Outcome measures included the incidence of preoperative anaemia, troponin rise after surgery, perioperative ECG changes consistent with ischaemia and the requirement for RBC transfusions. Results: In the observation period 24% of all patients were anaemic. The highest prevalence was observed in patients admitted for peripheral surgery (27%) compared to central open surgery (18%). Iron-deficiency anaemia was observed in 18% of peripheral surgery patients and in less than 10% in the remainder of the study cohort. All types of vascular surgeries caused an increase in troponin >20% indicating myocardial damage. This affected 70% of patients undergoing central open surgery and 40% of patients undergoing peripheral surgery and 55% of patients undergoing endovascular aortic repair. RBC transfusions were given in 70% of central open surgery, 16% of peripheral surgery patients and in 30% of endovascular aortic repairs. Total number of transfusions were higher in anaemic patients. The study is ongoing and will be completed in April 2019. Results for incidence of structural heart disease and the effects of intravenous iron treatment are pending. Conclusion: Vascular surgery patients have a high prevalence of anaemia. Myocardial injury and RBC transfusions are frequent during and after surgery. Data for the effects of intravenous iron treatment and FOCUS screening are awaited. Disclosure: Nothing to disclose