Indications for Blood Transfusion in Cardiac Surgery

The Relationship Between Transfusion in Cardiac Surgery Patients and Adverse Outcomes

OBJECTIVES

To understand if red blood cell (RBC) transfusions are independently associated with a risk of mortality, prolonged intubation, or infectious, cardiac, or renal morbid outcomes.

DESIGN

A retrospective review.

SETTING

A single-institution university hospital.

PARTICIPANTS

A total of 2,458 patients undergoing coronary bypass artery graft and/or valvular surgery from July 2014 through January 2018.

INTERVENTIONS

No interventions were done.

MEASUREMENTS AND MAIN RESULTS

The primary outcome was the occurrence of an adverse event or prolonged intubation. Infectious, cardiac, and renal composite outcomes were also defined. These composites, along with mortality, were analyzed individually and then combined to form the "any adverse events" composite. Preoperative demographic and intraoperative parameters were analyzed as univariate risk factors for adverse outcomes. Logistic regression was used to screen variables, with a p value criterion of p < 0.05 for entry into the model selection procedure. A backward selection algorithm was used with variable entry and retention criteria of p < 0.05 to select the final multivariate model. Multivariate logistic regression models were used to determine whether there was an association between the volume of RBC transfusion and the defined adverse event after adjusting for covariates. A p value < 0.01 was considered statistically significant in the final model of each aim to adjust for multiple comparisons. The final logistic models for each of the following outcomes indicate an increased risk of that outcome per each additional unit of RBC transfused. For prolonged intubation, the odds ratio (OR) was 1.493 (p < 0.0001), OR = 1.358 (p < 0.0001) for infectious composite outcomes, OR = 1.247 (p < 0.0001) for adverse renal outcomes, and OR = 1.467 (p < 0.0001) for any adverse event.

CONCLUSIONS

The authors demonstrated a strong independent association between RBC transfusion volume and adverse outcomes after cardiac surgery. Efforts should be undertaken, such as preoperative anemia management and control of coagulopathy, in order to minimize the need for RBC transfusion.

Perioperative Transfusion and Mortality for Cardiovascular Surgery: A Cohort Study Based on Population in Republic of Korea

Objective:This study aimed to evaluate the rate of transfusion for cardiovascular surgeries between 2010 and 2019 in Republic of Korea and the association between blood transfusion and postoperative mortality. Methods: Data were extracted from the National Health Insurance Service database in Republic of Korea. This study includes adult patients who underwent cardiovascular surgery between 1 January 2010 and 31 December 2019. The endpoints were in-hospital mortality and the 1-year all-cause mortality. Results: The analysis included 62,794 cases, with transfusions used in 88.8% of cases. Multivariable logistic regression revealed that older age, comorbidities, hospital admission through the emergency room, aortic procedures (versus coronary artery bypass grafting), cardiopulmonary bypass, repeat procedures, and supportive therapies during the intensive care (extracorporeal membrane oxygenation and mechanical ventilation) were risk factors for blood transfusion. Female sex was associated with a lower risk of transfusion. Perioperative blood transfusion was associated with a 6.87-fold increased risk of in-hospital mortality (odds ratio [OR]: 6.87, 95% confidence interval [CI]: 3.95, 11.93; p < 0.001) and a 3.20-fold increased risk of 1-year all-cause mortality (OR: 3.35, 95% CI: 2.75, 3.93; p < 0.001). Conclusions: Blood transfusion is used at a high rate in cardiovascular surgeries, and it was associated with increases in the risk of in-hospital and 1-year all-cause mortality. However, these correlations should be viewed with caution as emergent phenomena rather than causative. Understanding factors associated with the need for blood transfusion can assist surgeons in predicting the outcomes of cardiovascular surgery and in tailoring procedures as needed to optimize outcomes.

Delirium and depression in cardiac surgery: A comprehensive review of risk factors, pathophysiology, and management

BACKGROUND

Mental health and wellbeing continue to gain more attention as they are inextricably associated with clinical outcomes, particularly quality of life. Many medical ailments and major surgeries affect patients' mental health, including depression and delirium.

AIMS

The objective of this manuscript was to comprehensively review and critically examine the literature pertaining to cardiac surgery, depression, and delirium.

METHODS

This is a narrative review article. We performed our search analysis by using the following key words: "Cardiac Surgery", "Depression", "Delirium", "Clinical outcomes", and "Mental Health". Search analysis was done on MedLine PubMed, accessing indexed peer-reviewed publications.

RESULTS

Cardiac Surgery is a life-altering intervention indicated to improve morbidity and mortality in patients with cardiovascular diseases. Psychiatric conditions before and after cardiac surgery worsen patient prognosis and increase mortality rate. Specifically, preoperative depression increases postoperative depression and is associated with impaired functional status, slow physical recovery, and an increased readmission rate.

DISCUSSION

Although the exact pathophysiology between depression and cardiovascular disease (CVD) is unknown, several pathways have been implicated. Unmanaged depression can also lead to other psychological conditions such as delirium. Like depression, the exact association between delirium and CVD is not well understood, but believed to be multifactorial.

CONCLUSION

Herein, we provide a comprehensive review of the links between depression, delirium, and cardiovascular surgery. We critically examine the current data that pertains to the pathophysiology of these debilitating mental health issues in the context of cardiac surgery. Finally, we summarize the various treatment options available for managing depression and delirium in the cardiac surgery patient population.

Dynamic changes in platelets caused by shear stress in aortic valve stenosis

BACKGROUND AND OBJECTIVE:

Turbulent blood flow in patients with aortic valve stenosis (AS) results in morphological and functional changes in platelets and coagulation factors. The aim of this study is to determine how shear stress affects platelets and coagulation factors.

METHODS:

We retrospectively evaluated data from 78 patients who underwent AVR to treat AS between March 2008 and July 2017 at Kagoshima University Hospital.

RESULTS:

Platelet (PLT) count obviously decreased at three days after AVR, and increased above preoperative levels at the time of discharge. In contrast, platelet distribution width (PDW), mean platelet volume (MPV), and platelet large cell ratio (P-LCR) increased three days after AVR, then decreased to below preoperative levels. No differences were evident between groups with higher (HPPG > 100 mmHg) and lower (LPPG < 100 mmHg) peak pressure gradients (PPG) before AVR, whereas PLT count, PDW, MPV and P-LCR improved more in the HPPG group. Plateletcrit (PCT), which represents the total volume of platelets, increased after AVR due to decreased shear stress. High increasing rate of PCT was associated with lower PLT count, higher PDW and lower fibrinogen.

CONCLUSION:

Shear stress affects PLT count, PDW, and fibrinogen in patients with AS.

Evaluation of platelet count and platelet function analyzer - 100 testing for prediction of platelet transfusion following coronary bypass surgery

Platelet transfusions are commonly administered to treat bleeding in cardiac surgery. The aim of this study was to compare platelet (PLT) count and values of collagen adenosine diphosphate closure time (cADP-CT) measured by Platelet Function Analyzer (PFA) for prediction of PLT transfusion therapy following coronary bypass surgery. For this prospective observational study, 66 patients scheduled for coronary artery bypass grafting (CABG) who received early PLT transfusions (within 60 min after the operation) were enrolled. To assess changes in platelets, count and function, two time points were selected: 15 min before and 30 - 60 min after the end of PLT transfusion. The patients were divided into transfused and non-transfused with further PLT in the 48 h postoperatively. We used the receiver operating characteristics (ROC) curve to investigate whether the PLT count and cADP-CT values were predictors of PLT transfusion. The positive predictive values (PPV) of PLT count and cADP-CT after PLT transfusion for further PLT transfusion were 33% and 86% respectively, with a PLT count threshold of ≤200 × 10⁹/L and cADP-CT threshold of ≥118 s. The comparison among the ROC curves showed a statistical difference (p = .0002). In multiple regression analysis, cADP-CT was the strongest predictor for the number of PLT transfusion doses in the 48 h postoperatively. In CABG patients, the results of cADP-CT after PLT transfusion have a better predictive capacity for further PLT transfusions than the PLT count.

Minimally invasive versus conventional extracorporeal circulation circuits in patients undergoing coronary artery bypass surgery: a propensity-matched analysis

OBJECTIVES

Minimally invasive extracorporeal circulation circuits provide several advantages compared to conventional extracorporeal circulation circuits. We compared the results of a minimally invasive extracorporeal circulation system with those of conventional extracorporeal circulation system, in patients undergoing isolated coronary artery bypass grafting.

METHODS

We identified 753 consecutive patients who underwent coronary artery bypass grafting at our centre between October 2014 and September 2016. These patients were divided into two groups: a minimally invasive extracorporeal circulation group (M, n = 229) and a conventional extracorporeal circulation group (C, n = 524). Baseline parameters, details of cardiac surgery as well as postoperative complications and outcomes were compared by means of a propensity-matched analysis of 180 matched pairs.

RESULTS

The median EuroSCORE II was 1.3%. Transfusion requirement of packed red blood cells (p = 0.002) was lower in Group M compared to conventional extracorporeal circulation systems. There were no differences in hospital mortality or in rates of adverse events between the matched groups. Total in-hospital mortality of the cohort was 1.7%.

CONCLUSION

The use of minimally invasive extracorporeal circulation is associated with a significantly lower use of blood products after isolated coronary revascularisation. There were no differences concerning duration of surgery, complication rates and mortality between the groups. Therefore, the application of minimally invasive extracorporeal circulation systems should be considered as preferred technique in isolated coronary artery bypass grafting procedures.

A Novel Macroscale Acoustic Device for Blood Filtration

Retransfusion of a patient's own shed blood during cardiac surgery is attractive since it reduces the need for allogeneic transfusion, minimizes cost, and decreases transfusion related morbidity. Evidence suggests that lipid micro-emboli associated with the retransfusion of the shed blood are the predominant causes of the neurocognitive disorders. We have developed a novel acoustophoretic filtration system that can remove lipids from blood at clinically relevant flow rates. Unlike other acoustophoretic separation systems, this ultrasound technology works at the macroscale, and is therefore able to process larger flow rates than typical micro-electromechanical system (MEMS) scale acoustophoretic separation devices. In this work, we have first demonstrated the systematic design of the acoustic device and its optimization, followed by examining the feasibility of the device to filter lipids from the system. Then, we demonstrate the effects of the acoustic waves on the shed blood; examining hemolysis using both haptoglobin formation and lactate dehydrogenase release, as well as the potential of platelet aggregation or inflammatory cascade activation. Finally, in a porcine surgical model, we determined the potential viability of acoustic trapping as a blood filtration technology, as the animal responded to redelivered blood by increasing both systemic and mean arterial blood pressure.

The Role of Platelet Function Analyzer Testing in Cardiac Surgery Transfusion Management

BACKGROUND

Identifying high-risk patients for transfusion after cardiac operations would alter postoperative management. The aim of this study was to investigate closure time (CT) measured by platelet function analyzer (PFA) for prediction of bleeding and transfusions.

METHODS

66 patients were scheduled for coronary artery bypass graft (CABG) surgery and 30 patients for valve repair and replacement (non-CABG). Measurements of PFA-100® CT for collagen and adenosine diphosphate (cADP) and collagen and epinephrine (cEPI) were performed 15 min after protamine administration. Blood loss was measured, and the amount of transfusion products was recorded postoperatively.

RESULTS

The study demonstrated significant differences between CABG patients with cADP-CT ≥ 118 s and those with cADP-CT < 118 s with regard to blood loss for 24 h (p = 0.001) and blood loss for 25-48 h (p = 0.003) as well as fresh frozen plasma (p = 0.015), platelet (p > 0.001) and red blood cell (p = 0.002) units given in 48 postoperative h. There were no differences cardiopulmonary bypass when was applied. In non-CABG patients, there were no differences in blood loss and transfusion requirements with respect to cADP-CT and cEPI-CT.

CONCLUSION

Postoperative platelet dysfunction measured by a prolonged cADP-CT was significant predictor of blood loss and transfusion in CABG patients.

Allogeneic Blood Product Usage in Coronary Artery Bypass Grafting (CABG) with minimalized Extracorporeal Circulation System (MECC) Versus Standard On-Pump Coronary Artery Bypass Grafting

Aim:

Intraoperative allogeneic blood product transfusion (ABPT) in cardiac surgery is associated with worse overall outcome, including mortality. The objective of this study was to evaluate the ABPTs in minimalized extracorporeal cardiopulmonary (MECC^TM) compared with standard open system on-pump coronary revascularization.

Methods:

Data of 156 patients undergoing myocardial revascularization between September 2008 and September 2010 were reviewed. 83 patients were operated by the MECC technique and 73 were treated by standard extracorporeal circulation (sECC). ABPT and overall early postoperative complications were analyzed.

Results:

Operative mortality and morbidity were similar in both groups. ABPT in the MECC group was significantly lower than in the sECC group both intraoperatively (7.2 vs. 60.3% of patients p<0.001) and during the first five postoperative days (19.3 vs. 57.5%; p<0.001). “Skin to skin”- (214 ± 45 vs. 232 ± 45 min; p=0.012), cardiopulmonary bypass (CPB) - (82 ± 25 vs. 95 ± 26 min; p=0.014), and X-clamp- times (50 ± 16 vs. 56 ± 17 min; p=0.024) were significantly lower in the MECC group than in the sECC group. Length of ICU (intensive care unit) - and hospital stay were also significantly lower in the MECC group vs. the sECC group (26.7 ± 20.2 vs. 54.5 ± 68.9 h; p<0.001, and 12.0 ± 4.1 vs. 14.5 ± 4.6 days; p<0.001).

Conclusion:

Application of MECC as on-pump coronary artery bypass graft (CABG) results in significantly lower ABPT as well as shorter ICU and in-hospital stay. In order to achieve these benefits of MECC autologous retrograde priming, Bispectral index (BIS) monitoring, intraoperative cell salvage, meticulous hemostasis and strict peri- and postoperative volume management are crucial.

Bedside Assessment of the Microvascular Venous Compartment in Cardiac Surgery Patients With Valvular Diseases Undergoing Cardiopulmonary Bypass

OBJECTIVE

Blood volume reserve for venous return and the effects of cardiopulmonary bypass (CPB) on microvascular bed partitioning and blood flow were examined in patients with valvular diseases.

DESIGN

Prospective, consecutive, case-control study.

SETTING

Single university hospital.

PARTICIPANTS

The study comprised 20 adult cardiac surgery patients and 20 healthy volunteers.

INTERVENTIONS

Cardiovascular and microvascular variables were collected soon after the induction of anesthesia, after commencement of CPB, 20 minutes after separation from CPB, and in the intensive care unit.

MEASUREMENTS AND MAIN RESULTS

The unstressed and stressed volumes (Vu, Vs) and pressures therein (Pit, Ps) were measured in the brachioradial muscle with near-infrared spectroscopy, applying incremental venous occlusions. At the first time point, Vs and Pit showed lower and higher values, respectively, than those of control patients, but Vs increased with Vu during the study, whereas Pit remained unchanged. Fluid balance correlated with Pit (r = 0.83, p<0.001) and hemoglobin (r = 0.78, p = 0.004). A nonlinear regression was found between fluid balance and ΔVu (r = 0.90, p<0.001) [y = 1.85+37.43^(-0.01×x)]. The Vu/Pit and Vs/Ps ratios were lower than those of the control patients. Blood flow correlated to Vs/Ps (r = 0.75, p<0.001). The time constant was lower than reference (p = 0.005) and increased 10 times after CPB.

CONCLUSIONS

Cardiac surgery patients have a limited blood volume reserve for venous return due to a reduced microvascular bed capacitance. This study demonstrated that during CPB a positive fluid balance induced an extravascular pressure increase and further reduced blood volume reserve.

Blood Conservation in Cardiac Surgery

Blood transfusion is the most common procedure in cardiac surgery. Increasing evidence exists that excess transfusions are harmful to patients. Transfusion reactions and complications, including infection, immune modulation, and lung injury, are known complications but underreported; hence, their significance is often disregarded. Furthermore, a number of randomized trials have shown that a restrictive transfusion strategy is equal to if not better than a liberal transfusion strategy. Despite the evidence for the use of restrictive transfusion triggers, its dissemination in the cardiac surgical community has met with resistance. In this review, we outline the risks of transfusion, compare restrictive and liberal transfusion strategies in cardiac surgery, and finally outline perioperative interventions to minimize transfusion in the cardiac surgical patient.

The role of perioperative transfusion on long-term survival of veterans undergoing surgery

OBJECTIVE

To examine the influence of perioperative blood transfusions on perioperative outcomes and late survival.

BACKGROUND

Perioperative blood transfusion has been reported to have a negative impact on perioperative morbidity but its long-term effect on survival is unknown. The purpose of this study was to evaluate the effects of perioperative transfusion on perioperative outcomes and survival.

METHODS

We studied 12,345 surgical procedures from Veteran Administration Surgical Quality Improvement Program database from July 1998 through 2010. Patients with transfusion were compared with a severity-matched control group. We performed the Fisher exact test for comparison of categorical values and Wilcoxon rank sum test for continuous values. Multivariate regression was used to eliminate other confounding factors. The predictive value of multivariate risk model was tested with receiver-operator curves. Patients were matched using an optimal 1:1 digit-matching algorithm. All analyses were performed with NCSS-2007 version 1-12. P < 0.05 was considered statistically significant.

RESULTS

The 848 patients who received perioperative transfusions had higher unadjusted rates of mortality and decreased long-term survival. The odds ratio (OR) for 10 years mortality in transfused group was 2.92 and after adjusting for preoperative risk factors decreased to 1.40 (P < 0.01). However, after data were filtered for any perioperative complications, such an association was seen before, OR = 2.05 (P = 0.006), and was lost after propensity matching, OR = 1.19 (P = 0.35).

CONCLUSIONS

After filtering out perioperative complications and adjusting for preoperative morbidity, our final analysis did not reveal an increased long-term mortality. We conclude that transfusion may reduce long-term survival through its effects on perioperative complications.

Utilisation of blood components in cardiac surgery: a single-centre retrospective analysis with regard to diagnosis-related procedures

BACKGROUND

More blood components are required in cardiac surgery than in most other medical disciplines. The overall blood demand may increase as a function of the total number of cardiothoracic and vascular surgical interventions and their level of complexity, and also when considering the demographic ageing. Awareness has grown with respect to adverse events, such as transfusion-related immunomodulation by allogeneic blood supply, which can contribute to morbidity and mortality. Therefore, programmes of patient blood management (PBM) have been implemented to avoid unnecessary blood transfusions and to standardise the indication of blood transfusions more strictly with aim to improve patients' overall outcomes.

METHODS

A comprehensive retrospective analysis of the utilisation of blood components in the Department of Cardiac Surgery at the University Hospital of Münster (UKM) was performed over a 4-year period. Based on a medical reporting system of all medical disciplines, which was established as part of a PBM initiative, all transfused patients in cardiac surgery and their blood components were identified in a diagnosis- and medical procedure-related system, which allows the precise allocation of blood consumption to interventional procedures in cardiac surgery, such as coronary or valve surgery.

RESULTS

This retrospective single centre study included all in-patients in cardiac surgery at the UKM from 2009 to 2012, corresponding to a total of 1,405-1,644 cases per year. A blood supply was provided for 55.6-61.9% of the cardiac surgery patients, whereas approximately 9% of all in-patients at the UKM required blood transfusions. Most of the blood units were applied during cardiac valve surgery and during coronary surgery. Further surgical activities with considerable use of blood components included thoracic surgery, aortic surgery, heart transplantations and the use of artificial hearts. Under the measures of PBM in 2012 a noticeable decrease in the number of transfused cases was observed compared to the period from 2009 to 2011 before implementation of the PBM initiative (red blood cells p < 0.002; fresh frozen plasma p < 0.0006; platelets p < 0.00006).

CONCLUSION

Until now, cardiac surgery comes along with a significant blood supply. By using a case-related data evaluation programme, the consumption of each blood component can be linked to clinical performance groups and, if necessary, to individual patients. Based on the results obtained from this retrospective analysis, prospective studies are underway to begin conducting target / actual performance comparisons to better understand the individual decision-making by the attending physicians with respect to transfusions.

Longer RBC storage duration is associated with increased postoperative infections in pediatric cardiac surgery

OBJECTIVES

Infants and children undergoing open heart surgery routinely require multiple RBC transfusions. Children receiving greater numbers of RBC transfusions have increased postoperative complications and mortality. Longer RBC storage age is also associated with increased morbidity and mortality in critically ill children. Whether the association of increased transfusions and worse outcomes can be ameliorated by use of fresh RBCs in pediatric cardiac surgery for congenital heart disease is unknown.

INTERVENTIONS

One hundred and twenty-eight consecutively transfused children undergoing repair or palliation of congenital heart disease with cardiopulmonary bypass who were participating in a randomized trial of washed versus standard RBC transfusions were evaluated for an association of RBC storage age and clinical outcomes. To avoid confounding with dose of transfusions and timing of infection versus timing of transfusion, a subgroup analysis of patients only transfused 1-2 units on the day of surgery was performed.

MEASUREMENTS AND MAIN RESULTS

Mortality was low (4.9%) with no association between RBC storage duration and survival. The postoperative infection rate was significantly higher in children receiving the oldest blood (25-38 d) compared with those receiving the freshest RBCs (7-15 d) (34% vs 7%; p = 0.004). Subgroup analysis of subjects receiving only 1-2 RBC transfusions on the day of surgery (n = 74) also demonstrates a greater prevalence of infections in subjects receiving the oldest RBC units (0/33 [0%] with 7- to 15-day storage; 1/21 [5%] with 16- to 24-day storage; and 4/20 [20%] with 25- to 38-day storage; p = 0.01). In multivariate analysis, RBC storage age and corticosteroid administration were the only predictors of postoperative infection. Washing the oldest RBCs (> 27 d) was associated with a higher infection rate and increased morbidity compared with unwashed RBCs.

DISCUSSION

Longer RBC storage duration was associated with increased postoperative nosocomial infections. This association may be secondary in part, to the large doses of stored RBCs transfused, from single-donor units. Washing the oldest RBCs was associated with increased morbidity, possibly from increased destruction of older, more fragile erythrocytes incurred by washing procedures. Additional studies examining the effect of RBC storage age on postoperative infection rate in pediatric cardiac surgery are warranted.

Therapeutic options to minimize allogeneic blood transfusions and their adverse effects in cardiac surgery: a systematic review

INTRODUCTION

Allogeneic blood is an exhaustible therapeutic resource. New evidence indicates that blood consumption is excessive and that donations have decreased, resulting in reduced blood supplies worldwide. Blood transfusions are associated with increased morbidity and mortality, as well as higher hospital costs. This makes it necessary to seek out new treatment options. Such options exist but are still virtually unknown and are rarely utilized.

OBJECTIVE

To gather and describe in a systematic, objective, and practical way all clinical and surgical strategies as effective therapeutic options to minimize or avoid allogeneic blood transfusions and their adverse effects in surgical cardiac patients.

METHODS

A bibliographic search was conducted using the MeSH term "Blood Transfusion" and the terms "Cardiac Surgery" and "Blood Management." Studies with titles not directly related to this research or that did not contain information related to it in their abstracts as well as older studies reporting on the same strategies were not included.

RESULTS

Treating anemia and thrombocytopenia, suspending anticoagulants and antiplatelet agents, reducing routine phlebotomies, utilizing less traumatic surgical techniques with moderate hypothermia and hypotension, meticulous hemostasis, use of topical and systemic hemostatic agents, acute normovolemic hemodilution, cell salvage, anemia tolerance (supplementary oxygen and normothermia), as well as various other therapeutic options have proved to be effective strategies for reducing allogeneic blood transfusions.

CONCLUSION

There are a number of clinical and surgical strategies that can be used to optimize erythrocyte mass and coagulation status, minimize blood loss, and improve anemia tolerance. In order to decrease the consumption of blood components, diminish morbidity and mortality, and reduce hospital costs, these treatment strategies should be incorporated into medical practice worldwide.

Prevalence of preoperative anaemia in patients having first-time cardiac surgery and its impact on clinical outcome. A retrospective observational study

The prevalence of anaemia is increasing globally. It has a close association with perioperative blood transfusion which, in turn, results in an increased risk of postoperative complications. Undesirable effects are not only limited to short-term, but also have long-term implications. Despite this, many patients undergo cardiac surgery with undiagnosed and untreated anaemia. We designed a retrospective, observational study to estimate the prevalence of anaemia in patients having cardiac surgery in Auckland District Health Board, blood transfusion rates and associated clinical outcome. Two hundred of seven hundred and twelve (28.1%) patients were anaemic. Red blood cell (RBC) transfusion rates were significantly higher in the anaemic group compared to the non-anaemic group (160 (80%) vs. 192 (38%), p-value <0.0001, RR (CI 95%) 2.133 (1.870-2.433)). Transfusion rates for fresh frozen plasma (FFP), cryoprecipitate and platelets were also higher in the anaemic group. Anaemia was significantly associated with the development of new infection (14 (7%) vs. 15 (2.9%), p-value 0.0193, RR (CI 95%) 2.389 (1.175-4.859)), prolonged ventilation time (47.01 hours vs. 23.59 hours, p-value 0.0076) and prolonged intensive care unit (ICU) stay (80.23 hours vs. 50.27, p-value 0.0011). Preoperative anaemia is highly prevalent and showed a clear link with significantly higher transfusion rates and postoperative morbidity. It is vital that a preoperative management plan for the correction of anaemia should be sought to improve patient safety and outcome.

Survey on stated transfusion practices in PICUs*

OBJECTIVES

To analyze the RBC transfusion practice patterns among pediatric intensivists in light of the new evidence advocating for a restrictive transfusion strategy.

DESIGN

Self-administered questionnaire.

SETTING

PICUs.

SUBJECTS

Intensivists and fellows in pediatric critical care medicine.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Scenario-based survey carried out among North American and European intensivists, working in tertiary-care PICUs. Respondents were asked to report their decisions with regard to RBC transfusion in stable critically ill children with bronchiolitis, septic shock, trauma, or tetralogy of Fallot repair scenarios. Answers were compared with those of a similar scenario-based survey administered to pediatric intensivists in 1997. Ninety-seven respondents were retained for the study, the majority from the United States, Canada, and France. In 2010, respondents reported that the mean (± SD) transfusion threshold was a hemoglobin level of 7.7 ± 1.0 g/dL for bronchiolitis, 8.1 ± 1.2 g/dL for trauma, 9.1 ± 1.2 g/dL for a tetralogy of Fallot repair, and 9.2 ± 1.0 g/dL for septic shock. For all clinical scenarios, there was a trend toward a more restrictive transfusion approach (a threshold ≤ 7 g/dL) in 2010 compared with 1997: a restrictive strategy was adopted by 55.7% of respondents in 2010 versus 37.0% in 1997 (p = 0.01) with the scenario of bronchiolitis, 8.3% versus 3.4% (p = 0.16) with septic shock, 38.1% versus 9.0% (p < 0.001) with trauma, and 16.0% versus 7.9% (p = 0.10) with tetralogy of Fallot repair.

CONCLUSIONS

Stated transfusion practice patterns of pediatric intensivists appear to be evolving toward a more restrictive approach two and a half years after the publication of the Transfusion Requirement in PICU trial. Incomplete implementation of new knowledge with regard to the safety of a restrictive transfusion approach in stable PICU patients is perplexing and requires further studies.

Implementation of a transfusion algorithm to reduce blood product utilization in pediatric cardiac surgery

AIM

The goal of this project is to measure the impact of standardization of transfusion practice on blood product utilization and postoperative bleeding in pediatric cardiac surgery patients.

BACKGROUND

Transfusion is common following cardiopulmonary bypass (CPB) in children and is associated with increased mortality, infection, and duration of mechanical ventilation. Transfusion in pediatric cardiac surgery is often based on clinical judgment rather than objective data. Although objective transfusion algorithms have demonstrated efficacy for reducing transfusion in adult cardiac surgery, such algorithms have not been applied in the pediatric setting.

METHODS

This quality improvement effort was designed to reduce blood product utilization in pediatric cardiac surgery using a blood product transfusion algorithm. We implemented an evidence-based transfusion protocol in January 2011 and monitored the impact of this algorithm on blood product utilization, chest tube output during the first 12 h of intensive care unit (ICU) admission, and predischarge mortality.

RESULTS

When compared with the 12 months preceding implementation, blood utilization per case in the operating room odds ratio (OR) for the 11 months following implementation decreased by 66% for red cells (P = 0.001) and 86% for cryoprecipitate (P < 0.001). Blood utilization during the first 12 h of ICU did not increase during this time and actually decreased 56% for plasma (P = 0.006) and 41% for red cells (P = 0.031), indicating that the decrease in OR transfusion did not shift the transfusion burden to the ICU. Postoperative bleeding, as measured by chest tube output in the first 12 ICU hours, did not increase following implementation of the algorithm. Monthly surgical volume did not change significantly following implementation of the algorithm (P = 0.477). In a logistic regression model for predischarge mortality among the nontransplant patients, after accounting for surgical severity and duration of CPB, use of the transfusion algorithm was associated with a 0.247 relative risk of mortality (P = 0.013).

CONCLUSIONS

These results indicate that introduction of an objective transfusion algorithm in pediatric cardiac surgery significantly reduces perioperative blood product utilization and mortality, without increasing postoperative chest tube losses.

Clinical and economic outcomes associated with blood transfusions among elderly Americans following coronary artery bypass graft surgery requiring cardiopulmonary bypass

BACKGROUND

Blood transfusion occurring during hospitalisation for heart surgery has been shown to be associated with increased morbidity and mortality and with increased time spent in hospital, use of healthcare services, and costs. The objective of this study was to assess how perioperative blood transfusion among adults 65 years and older who underwent coronary artery bypass graft surgery requiring cardiopulmonary bypass in the United States is associated with immediate and longer term clinical and economic outcomes.

MATERIALS AND METHODS

Using data from a 5% random sample of Medicare patients who underwent their first (within 2 years) coronary artery bypass graft requiring cardiopulmonary bypass procedure in 2005 or 2006, this study estimated associations (hazard ratios and regression coefficients) between transfusion status (received or not) and complications after surgery, serious adverse events, death, and costs using Cox proportional hazard and generalised linear models adjusting for patients' demographic and clinical characteristics.

RESULTS

Adjusted hazard ratios were statistically significant (P<0.05) for risks of complications (1.20), serious adverse events (1.58), and death (1.49). There was also a statistically significantly (P≤0.01) and strong relationship between receiving transfused blood and Medicare payments over the subsequent 45 months following discharge ($5,778 per calendar quarter for those receiving transfusion vs $5,197; all costs are measured in 2011 USD).

CONCLUSION

Blood transfusion during hospitalisation for coronary artery bypass graft requiring cardiopulmonary bypass was significantly associated with increased long-term post-operative morbidity, mortality, and overall healthcare costs. This study contributes to the evidence demonstrating an association between transfusion and adverse clinical and economic outcomes by using a nationally representative longitudinal cost and utilisation database.

[Blood transfusion during heart surgery. A retrospective nested case-control study]

OBJECTIVE

To assess the correlation between intraoperative packed red blood cells transfusion and adverse outcome in a Spanish cohort of cardiac surgery patients.

METHODS

Retrospective observational multicentre study. An analysis was performed on the data from 927 cardiac surgery patients treated in 24 Spanish hospitals in 2007. Patients who received intraoperative transfusions were compared with non-transfused patients. Multivariate analyses were performed (including, among others, several items from the Euroscore, surgery type, basal renal status and haemoglobin levels, and Thakar score).

RESULTS

Every transfusion of packed red cells was associated with increased postoperative risk of acute kidney damage at 72 hours after surgery, prolonged mechanical ventilation, and need for haemodynamic support. Moreover, transfused patients showed an increased in-hospital mortality rates (Adjusted OR: 1.30; 95% CI: 1.19-1.42), as well as longer hospital stays (almost 4 days).

CONCLUSIONS

In this cohort of patients, intraoperative transfusion might independently predict higher risk of early acute kidney damage, prolonged postoperative mechanical ventilation, and a need for haemodynamic support, and reduced short term survival (adjusted OR for mortality: 1.30; 95% CI: 1.19-1.42), and longer hospital stays (4 days longer).

Comparison of two red-cell transfusion strategies after pediatric cardiac surgery: a subgroup analysis

OBJECTIVE

To determine the impact of a restrictive vs. a liberal transfusion strategy on new or progressive multiple organ dysfunction syndrome in children post cardiac surgery. The optimal transfusion threshold after cardiac surgery in children is unknown.

DESIGN

Randomized, controlled trial.

SETTING

Tertiary pediatric intensive care units.

PATIENTS

Participants are a subgroup of pediatric patients post cardiac surgery from the TRIPICU (Transfusion Requirements in Pediatric Intensive Care Units) study. Exclusion criteria specific to the cardiac surgery subgroup included: age <28 days and patients remaining cyanotic.

INTERVENTION

Critically ill children with a hemoglobin < or = 95 g/L within 7 days of pediatric intensive care unit admission were randomized to receive prestorage leukocyte-reduced red-cell transfusion if their hemoglobin dropped either <70 g/L (restrictive) or 95 g/L (liberal).

MEASUREMENTS AND MAIN RESULTS

Postoperative cardiac patients (n = 125) from seven centers were enrolled. The restrictive (n = 63) and liberal (n = 62) groups were similar at baseline in age (mean +/- standard deviation = 31.4 +/- 38.1 mos vs. 26.4 +/- 39.1 mos), surgical procedure, severity of illness (Pediatric Risk of Mortality score = 3.4 +/- 3.2 vs. 3.2 +/- 3.2), multiple organ dysfunction syndrome (46% vs. 44%), mechanical ventilation (62% vs. 60%), and hemoglobin (83 vs. 80 g/L). Mean hemoglobin remained 21 g/L lower in the restrictive group after randomization. No significant difference was found in new or progressive multiple organ dysfunction syndrome (primary outcome) in the restrictive group vs. liberal group (12.7% vs. 6.5%; p = .36), pediatric intensive care unit length of stay (7.0 +/- 5.0 days vs. 7.4 +/- 6.4 days) or 28-day mortality (3.2% vs. 3.2%).

CONCLUSION

In this subgroup analysis of cardiac surgery patients, a restrictive red-cell transfusion strategy, as compared with a liberal one, was not associated with any significant difference in new or progressive multiple organ dysfunction syndrome, but this evidence is not definitive.

Increased mortality, morbidity, and cost associated with red blood cell transfusion after cardiac surgery

PURPOSE OF REVIEW

Literature since 2006 was reviewed to identify the harms and costs of red blood cell (RBC) transfusion.

RECENT FINDINGS

Several studies, in people having various cardiac surgery operations, found strong associations of RBC transfusion with mortality and postoperative morbidity. The effect on mortality was strongest close to the time of operation but extended to 5 years. Morbidity outcomes included serious wound and systemic infections, renal failure, prolonged ventilation, low cardiac index, myocardial infarction, and stroke. RBC transfusion was also strongly associated with increased cardiac intensive care unit and ward postoperative stay, and hence, increased cost of admission; available studies did not consider all resources used and the associated costs.

SUMMARY

The harms of RBC transfusion have potentially serious and long-term consequences for patients and are costly for health services. This evidence should shift clinicians' equipoise towards more restrictive transfusion practice. The immediate aim should be to avoid transfusing a small number of RBC units for general malaise attributed to anaemia, a practice that appears to occur in about 50% of transfused patients. Randomized trials comparing restrictive and liberal transfusion triggers are urgently needed to directly compare the benefits and harms from RBC transfusion.

Prevalence and Risk Factors for Postoperative Delirium in a Cardiovascular Intensive Care Unit

Background Delirium after cardiac surgery is a common complication in cardiovascular intensive care units. The prevalence of delirium and its likely risk factors have not previously been explored in a single sample of postoperative cardiac patients in an intensive care unit.

Objective To compare a variety of characteristics in patients with and without delirium and to identify risk factors associated with delirium in patients hospitalized in an intensive care unit after cardiac surgery.

Methods A retrospective chart review was used to collect data on 288 patients who had open heart surgery during the period 2004 to 2005 at Chang Gung Memorial Hospital in northern Taiwan. A researcher-designed checklist of 52 patient-related risk factors for delirium was used to collect preoperative, intra-operative, and postoperative data. All patients were assessed by psychiatrists, and delirium was diagnosed according to criteria of the Diagnostic and Statistical Manual of Mental Disorders, fourth edition. Data were analyzed via univariate analysis and multivariate logistic regression.

Results The prevalence of postoperative delirium was 41.7%. Patients with and without delirium differed significantly on 29 variables. Four postoperative factors, hematocrit less than 30%, cardiogenic shock, hypoalbuminemia, and acute infection, were significant, independent predictors of postoperative delirium.

Conclusions The results of this study can be used to develop a revised checklist of 29 preoperative, intraoperative, and postoperative risk factors for delirium, with special attention to the 4 predictive postoperative factors. Use of such a checklist may facilitate the ability to prevent or detect delirium early and provide suitable treatment.

Increased mortality, postoperative morbidity, and cost after red blood cell transfusion in patients having cardiac surgery

BACKGROUND

Red blood cell transfusion can both benefit and harm. To inform decisions about transfusion, we aimed to quantify associations of transfusion with clinical outcomes and cost in patients having cardiac surgery.

METHODS AND RESULTS

Clinical, hematology, and blood transfusion databases were linked with the UK population register. Additional hematocrit information was obtained from intensive care unit charts. Composite infection (respiratory or wound infection or septicemia) and ischemic outcomes (myocardial infarction, stroke, renal impairment, or failure) were prespecified as coprimary end points. Secondary outcomes were resource use, cost, and survival. Associations were estimated by regression modeling with adjustment for potential confounding. All adult patients having cardiac surgery between April 1, 1996, and December 31, 2003, with key exposure and outcome data were included (98%). Adjusted odds ratios for composite infection (737 of 8516) and ischemic outcomes (832 of 8518) for transfused versus nontransfused patients were 3.38 (95% confidence interval [CI], 2.60 to 4.40) and 3.35 (95% CI, 2.68 to 4.35), respectively. Transfusion was associated with increased relative cost of admission (any transfusion, 1.42 times [95% CI, 1.37 to 1.46], varying from 1.11 for 1 U to 3.35 for >9 U). At any time after their operations, transfused patients were less likely to have been discharged from hospital (hazard ratio [HR], 0.63; 95% CI, 0.60 to 0.67) and were more likely to have died (0 to 30 days: HR, 6.69; 95% CI, 3.66 to 15.1; 31 days to 1 year: HR, 2.59; 95% CI, 1.68 to 4.17; >1 year: HR, 1.32; 95% CI, 1.08 to 1.64).

CONCLUSIONS

Red blood cell transfusion in patients having cardiac surgery is strongly associated with both infection and ischemic postoperative morbidity, hospital stay, increased early and late mortality, and hospital costs.