Prediction of massive blood transfusion in cardiac surgery

Abstract

Purpose:In cardiac surgery with cardiopulmonary bypass (CPB), excessive blood loss requiring the transfusion of multiple red blood cell (RBC) units is a common complication that is associated with significant morbidity and mortality. The objective of this study was to develop a prediction rule for massive blood transfusion (MBT) that could be used to optimize the management of, and research on, at-risk patients.Methods: Data were collected prospectively over the period from 2000 to 2005, on patients who underwent surgery with CPB at one hospital. Patients who received ≥ five units of RBC within one day of surgery were classified as MBT. Logistic regression was used to appropriately select and weigh perioperative variables in the prediction rule, which was developed on the initial 60% of the sample and validated on the remaining 40%.Results: Of the 10,667 patients included, 925 (8.7%) had MBT. The clinical prediction rule included 12 variables (listed in order of predictive value: CPB duration, preoperative hemoglobin concentration, body surface area, nadir CPB hematocrit, previous sternotomy, preoperative shock, preoperative platelet count, urgency of surgery, age, surgeon, deep hypothermic circulatory arrest, and type of procedure) and was highly discriminative (c-index = 0.88). In the validation set, those classified as low-, moderate-, and high-risk by a simple risk score derived from the prediction rule had a 5%, 27%, and 58% chance of MBT, respectively. Conclusion:A clinical prediction rule was developed that accurately identified patients at low-risk or high-risk for MBT. Studies are needed to determine the external generalizability and clinical utility of the prediction rule. Objectif : En cardiochirurgie avec circulation extracorporelle (CEC), une perte de sang excessive exigeant la transfusion de multiples unités de culots globulaires (CG) est une complication

Diagnostic and therapeutic medical devices for safer blood management in cardiac surgery: systematic reviews, observational studies and randomised controlled trials

“…These identify age, female sex, low body mass index (BMI), preoperative anaemia, chronic kidney disease, poor left ventricular function and recent myocardial ischaemia as predictive of excessive bleeding or MBT. 63,64 The mechanism by which these factors contribute to bleeding is poorly understood. Existing scores are not widely used because of the limited generalisability of risk models developed in single centres or subpopulations of patients.…”

“…In addition to standard care, current blood management guidelines recommend (class 1, level of evidence C 24 ) that patients undergo a formal assessment and documentation of bleeding risk. Risk scores that may accurately predict the risk of bleeding and red cell transfusion exist; 63,64,88,89 however, these are not widely used. The predictive accuracy of any new diagnostic test should therefore complement appropriate clinical assessment and the benefits of additional testing should be assessed beyond those attributable to clinical assessment combined with standard testing.…”

“…63 The score was designed to identify patients at risk of MBT, defined as transfusion of > 4 units of red cells within 48 hours of surgery, which is considered an index of severe bleeding. This was based on a previous study that had demonstrated significant increases in mortality with transfusions of greater volumes of red cells than this volume, 10 with the rationale that identifying and reducing transfusion in these patients was more likely to improve clinical outcomes.…”

“…64 We were unable to replicate the RBC research group score 63 in our data as it required surgeon-specific data and information on preoperative platelet count, which were not recorded in the four data sets. All analyses were carried out using Stata version 11.…”

Patient-oriented blood-saving concept in operations with cardiopulmonary bypass

“…Сниженный уровень Hb приводит к потребности замещения донорскими средами, что уве-личивает риск трансфузионных осложнений (в том числе TRALI) и смертности в 5-летний период наблюдения [2,3]. Напротив, снижение уровня гемодилюции значимо со-кращает потребность в трансфузионной терапии [4]. Ми-нимизация самого контура ИК путем уменьшения объема первичного заполнения или ретроградное заполнение ИК, снижающие уровень гемодилюции, приводили к по-вышению постперфузионного уровня Hb и снижению вы-раженности системного воспаления в постперфузионном периоде [5,6].…”