A simple clinical model for planning transfusion quantities in heart surgery

<p>Abstract</p> <p>Background</p> <p>Patients undergoing heart surgery continue to be the largest demand on blood transfusions. The need for transfusion is based on the risk of complications due to poor cell oxygenation, however large transfusions are associated with increased morbidity and risk of mortality in heart surgery patients. The aim of this study was to identify preoperative and intraoperative risk factors for transfusion and create a reliable model for planning transfusion quantities in heart surgery procedures.</p> <p>Methods</p> <p>We performed an observational study on 3315 consecutive patients who underwent cardiac surgery between January 2000 and December 2007. To estimate the number of packs of red blood cells (PRBC) transfused during heart surgery, we developed a multivariate regression model with discrete coefficients by selecting dummy variables as regressors in a stepwise manner. Model performance was assessed statistically by splitting cases into training and testing sets of the same size, and clinically by investigating the clinical course details of about one quarter of the patients in whom the difference between model estimates and actual number of PRBC transfused was higher than the root mean squared error.</p> <p>Results</p> <p>Ten preoperative and intraoperative dichotomous variables were entered in the model. Approximating the regression coefficients to the nearest half unit, each dummy regressor equal to one gave a number of half PRBC. The model assigned 4 units for kidney failure requiring preoperative dialysis, 2.5 units for cardiogenic shock, 2 units for minimum hematocrit at cardiopulmonary bypass less than or equal to 20%, 1.5 units for emergency operation, 1 unit for preoperative hematocrit less than or equal to 40%, cardiopulmonary bypass time greater than 130 minutes and type of surgery different from isolated artery bypass grafting, and 0.5 units for urgent operation, age over 70 years and systemic arterial hypertension.</p> <p>Conclusions</p> <p>The regression model proved reliable for quantitative planning of number of PRBC in patients undergoing heart surgery. Besides enabling more rational resource allocation of costly blood-conservation strategies and blood bank resources, the results indicated a strong association between some essential postoperative variables and differences between the model estimate and the actual number of packs transfused.</p

Evaluation of the use of blood in surgeries as a tool to change patterns for requesting blood product reserves

OBJECTIVES: Thirty to sixty percent of prepared blood products are not transfused. Blood reserves for surgeries lead to many unused blood products, which increases hospital costs. The aim of this study is to identify the request and use profiles of blood products for elective surgeries in different surgical specialties, the influence of surgery time and demographic, clinical, and laboratory variables on the number of red blood cells (RBCs) used and to calculate the rate of transfused patients (RTP) and cross-matched and transfused (C/T) RBCs. METHODS: Observational and prospective studies. Sociodemographic, clinical and quantitative data on the request and use of blood products were collected. The influence of the data on the use of RBCs was examined by binary logistic regression. Chi-square, one-way ANOVA and Kruskal-Wallis tests were utilized to compare the data among the specialties. RESULTS: In total, 822 procedures were included. Most of the requested blood products were not used, even 24 hours postoperatively. Of the 2,483 RBC units, 314 were transfused, leaving 87.6% unused; however, cardiac, digestive tract, vascular, gynecologic, urologic and thoracic surgery procedures transfused 50%, 25%, 16.5%, 11%, 9.5% and 8.1% of requested RBCs, respectively. The factors that influenced the transfusions were age, time of surgery and cardiac surgeries. The RTP was 410% in 22 surgical types and o1% in 24 surgical types, and 88% of samples presented a C/T ratio 42.5. CONCLUSION: The RTP and C/T ratios can guide RBC requests in the preoperative period. Knowing the standard of use of blood products and developing protocols enables the optimization of reserves, reduction of costs and improvement of care

Aplicação do índice de pacientes transfundidos e do índice de utilização de concentrado de hemácias no serviço de hemoterapia do Hospital Universitário Cassiano Antônio de Moraes, como ferramenta para melhoria das práticas hemoterápicas transfusionais.

Introdução: Estudos demonstram que cerca de 30-60% das unidades de sangue preparadas para transfusão não são transfundidas. Os hemocomponentes (HC) preparados e não transfundidos propiciam maior consumo de reagentes e recursos humanos. Reduzir o preparo de HC para reserva cirúrgica é uma área de oportunidade para minimizar custos e otimizar o uso racional de HC. Objetivos: a)identificar o perfil de solicitação e utilização de HC para cirurgias eletivas e a influência de variáveis demográficas, clínicas, laboratoriais e o tempo de cirurgia no número de transfusões; b) construir a Escala de Requisição Máxima de Sangue para Cirurgias (ERMSC) eletivas do Hospital Universitário Cassiano Antônio de Moraes (HUCAM); c) demonstrar o custo de reagentes para reserva pré-operatória e a possibilidade de economia. Métodos: Estudo observacional, prospectivo, realizado no período de 01/02/2015 a 31/01/2016, no HUCAM. Foram levantados dados sociodemográficos e clínicos (sexo, idade, diagnóstico, tipo de cirurgia) e dados quantitativos de solicitação e utilização de concentrado de hemácias (CH) das cirurgias eletivas neste período. Foi elaborado a ERMSC com os dados de utilização do sangue do HUCAM e calculado o custo do padrão de solicitação de CH e possível economia com o uso das ERMSC. Resultados: Foram avaliadas 822 cirurgias com necessidade de reserva de HC. A média de idade foi de 55,1 anos (95% IC 54,1; 56,2). A mediana de CH solicitado foi 3 unidades (0-8). A mediana de solicitação de reserva de plaquetas foi 0, exceto para as cirurgias cardíacas (8 unidades (0-10)). A mediana de solicitação de plasma fresco congelado foi 3 unidades (0-10). Foram transfundidos 135 pacientes (16,4%). As cirurgias cardíacas transfundiram 50%, seguidas do aparelho digestivo (25%), vasculares (16,5%), ginecologia (11%), urologia (9,5%) e torácica (8,1%). Os fatores que influenciaram a transfusão foram: idade (OR 1.025, 95% IC 1.006, 1.045), tempo de cirurgia (OR 1.004, 95% IC 1.001, 1.006) e as cirurgias cardíacas (OR 7,83 95% IC 1.58, 38.74). Dos 51 tipos de cirurgias avaliadas 22 apresentaram Índice de pacientes transfundidos (IPT) >10% e 29 IPT<10%, sendo elaborada a ERMSC. A cirurgia cardíaca apresenta o maior custo de solicitação de CH (mediana: R$49,73; min 35,5 máx 77,89), a ginecologia o menor custo (mediana R$ 35,65; min 28,61 máx 49,73) p<0,01. Ao adotar qualquer metodologia de ERMSC proporcionaria uma economia financeira de 17% a 37%. Conclusão: A mediana de solicitação de CH,foi menor para a ginecologia e maior para a cirurgia cardíaca. A maioria das cirurgias não utilizaram os HC solicitados. Idade, tempo de cirurgia e cirurgia cardíaca aumentaram a chance de utilização de CH. Todas as especialidades poderiam economizar com os custos de solicitação de CH e as cirurgias cardíacas apresentariam maior possibilidade de economia