Hospital variation in transfusion and infection after cardiac surgery: a cohort study

A precise blood transfusion evaluation model for aortic surgery: a single-center retrospective study

Cardiac aortic surgery is an extremely complicated procedure that often requires large volume blood transfusions during the operation. Currently, it is not possible to accurately estimate the intraoperative blood transfusion volume before surgery. Therefore, in this study, to determine the clinically precise usage of blood for intraoperative blood transfusions during aortic surgery, we established a predictive model based on machine learning algorithms. We performed a retrospective analysis on 4,285 patients who received aortic surgery in Beijing Anzhen Hospital between January 2018 and September 2022. Ultimately, 3,654 patients were included in the study, including 2,557 in the training set and 1,097 in the testing set. By utilizing 13 current mainstream models and a large-scale cardiac aortic surgery dataset, we built a novel machine learning model for accurately predicting intraoperative red blood cell transfusion volume. Based on the transfusion-related risk factors that the model identified, we also established the relevant variables that affected the results. The results revealed that decision tree models were the most suitable for predicting the blood transfusion volume during aortic surgery. In particular, the mean absolute error for the best-performing extremely randomized forest model was 1.17 U, while the R2 value was 0.50. Further exploration into intraoperative blood transfusion during aortic surgery identified erythrocytes, estimated operation duration, body weight, sex, red blood cell count, and D-dimer as the six most significant risk factors. These factors were subsequently analyzed for their influence on intraoperative blood transfusion volume in relevant patients, as well as the protective threshold for prediction. The novel intraoperative blood transfusion prediction model for cardiac aorta surgery in this study effectively assists clinicians in accurately calculating blood transfusion volumes and achieving effective utilization of blood resources. Furthermore, we utilize interpretability technology to reveal the influence of critical risk factors on intraoperative blood transfusion volume, which provides an important reference for physicians to provide timely and effective interventions. It also enables personalized and precise intraoperative blood usage.

Impact of Blood Products Transfusion on Patients in the Immediate Post-Lung Transplant Period: A Cohort Study

BACKGROUND Anemia is common in post-transplant patients. Blood product transfusion is associated with mortality and rejection in solid organ transplants. In lung transplant recipients, transfusion predisposes to primary graft dysfunction (PGD). The adverse effects and associated mortality of perioperative transfusions in lung transplant recipients have not been evaluated. This study examined the effects of perioperative blood transfusions in lung transplant recipients. MATERIAL AND METHODS We conducted a retrospective study of the effects of blood product transfusions in patients who received single- or double-lung transplantation at Houston Methodist Hospital between August 2017 and September 2019. Univariable and multiple logistic regression modeling were used to determine the characteristics associated with single events as well as a composite outcome within 30 days (including mortality, acute myocardial infarction, acute stroke, lower respiratory tract infection, urinary tract infection, surgical site infections, or PGD). RESULTS A total of 232 patients received lung transplants between December 2015 and September 2019 at our center. Univariable analysis revealed an increased risk of PGD (P<0.001), more mechanical ventilation days (P<0.001), more ICU days post-transplant (P<0.001), and greater need for ECMO support (P=0.001) in patients who received blood product transfusions. In univariate analysis, the composite outcome was also more common (P=0.01) in patients who received any transfusion perioperatively. A total of 7 patients died within 30 days from transplant, and they were all in the transfused group. CONCLUSIONS Among lung transplant recipients, PGD, ICU days, need for mechanical ventilation and ECMO support, and total composite events were significantly greater in patients who received blood transfusion perioperatively.

Development and validation of a machine learning prediction model for perioperative red blood cell transfusions in cardiac surgery

OBJECTIVE

Several machine learning (ML) models have been used in perioperative red blood cell (RBC) transfusion risk for cardiac surgery with limited generalizability and no external validation. Hence, we sought to develop and comprehensively externally validate a ML model in a large dataset to estimate RBC transfusion in cardiac surgery with cardiopulmonary bypass (CPB).

DESIGN

A retrospective analysis of a multicenter clinical trial (NCT03782350).

PATIENTS

The study patients who underwent cardiac surgery with CPB came from four cardiac centers in China and Medical Information Mart for Intensive Cared (MIMIC-IV) dataset.

MEASUREMENTS

Data from Fuwai Hospital were used to develop an individualized prediction model for RBC transfusion. The model was externally validated in the data from three other centers and MIMIC-IV dataset. Twelve models were constructed.

MAIN RESULTS

A total of 11,201 eligible patients were included in the model development (2420 in Fuwai Hospital) and external validation (563 in the other three centers and 8218 in the MIMIC-IV dataset). A significant difference was observed between the Logistic Regression and CatboostClassifier (0.72 Vs. 0.74, P = 0.031) or RandomForestClassifier (0.72 Vs. 0.75 p = 0.012) in the external validation and MIMIV-IV datasets (age ≤ 70:0.63 Vs. 0.71, p < 0.001; age > 70:0.63 Vs. 0.70, 0.63 Vs. 0.71, p < 0.001). The CatboostClassifier and RandomForestClassifier model was comparable in development (0.83 Vs. 0.82, p = 0.419), external (0.74 Vs. 0.75, p = 0.268), and MIMIC-IV datasets (age ≤ 70: 0.71 Vs. 0.71, p = 0.574; age > 70: 0.70 Vs. 0.71, p = 0.981). Of note, they outperformed other ML models with excellent discrimination and calibration. The CatboostClassifier and RandomForestClassifier models achieved higher area under precision-recall curve and lower brier loss score in validation and MIMIC-IV datasets. Additionally, we confirmed that low preoperative hemoglobin, low body mass index, old age, and female sex increased the risk of RBC transfusion.

CONCLUSIONS

In our study, enrolling a broad range of cardiovascular surgeries with CPB and utilizing a restrictive RBC transfusion strategy, robustly validates the generalizability of ML algorithms for predicting RBC transfusion risk. Notably, the CatboostClassifier and RandomForestClassifier exhibit strong external clinical applicability, underscoring their potential for widespread adoption. This study provides compelling evidence supporting the efficacy and practical value of ML-based approaches in enhancing transfusion risk prediction in clinical practice.

The importance of liver function assessment before cardiac surgery: A narrative review

The demand for cardiac surgery procedures is increasing globally. Thanks to an improvement in survival driven by medical advances, patients with liver disease undergo cardiac surgery more often. Liver disease is associated with the development of heart failure, especially in patients with advanced cirrhosis. Cardiovascular risk factors can also contribute to the development of both cardiomyopathy and liver disease and heart failure itself can worsen liver function. Despite the risk that liver disease and cirrhosis represent for the perioperative management of patients who undergo cardiac surgery, liver function is often not included in common risk scores for preoperative evaluation. These patients have worse short and long-term survival when compared with other cardiac surgery populations. Preoperative evaluation of liver function, postoperative management and close postoperative follow-up are crucial for avoiding complications and improving results. In the present narrative review, we discuss the pathophysiological components related with postoperative complications and mortality in patients with liver disease who undergo cardiac surgery and provide recommendations for the perioperative management.

Factors affecting mortality after coronary bypass surgery: a scoping review

Objectives

Previous research reports numerous factors of post-operative mortality in patients undergoing isolated coronary artery bypass graft surgery. However, this evidence has not been mapped to the conceptual framework of care improvement. Without such mapping, interventions designed to improve care quality remain unfounded.

Methods

We identified reported factors of in-hospital mortality post isolated coronary artery bypass graft surgery in adults over the age of 19, published in English between January 1, 2000 and December 31, 2019, indexed in PubMed, CINAHL, and EMBASE. We grouped factors and their underlying mechanism for association with in-hospital mortality according to the augmented Donabedian framework for quality of care.

Results

We selected 52 factors reported in 83 articles and mapped them by case-mix, structure, process, and intermediary outcomes. The most reported factors were related to case-mix (characteristics of patients, their disease, and their preoperative health status) (37 articles, 27 factors). Factors related to care processes (27 articles, 12 factors) and structures (11 articles, 6 factors) were reported less frequently; most proposed mechanisms for their mortality effects.

Conclusions

Few papers reported on factors of in-hospital mortality related to structures and processes of care, where intervention for care quality improvement is possible. Therefore, there is limited evidence to support quality improvement efforts that will reduce variation in mortality after coronary artery bypass graft surgery.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13019-022-01784-z.

Preoperative patient factors associated with blood product use in cardiac surgery, a retrospective cohort study

BACKGROUND

Cardiac surgery is associated with a high rate of blood use. The aim of this study is to identify preoperative patient factors associated with allogeneic Red Blood Cell (RBC) or non-Red Blood Cell (NRBC) use in cardiac surgery.

METHODS

All adult cardiac surgical procedures conducted at a single Western Australian institution were retrospectively analysed. Data was collected from the Australia and New Zealand Cardiac Surgery Database from 2015 to 2018. A number of preoperative factors were identified, relating to past medical history or preoperative cardiac status. Outcome 1 was defined as the use of one or more RBC products intra or post-operatively. Outcome 2 was defined as the use of one or more NRBC products intra or post-operatively. Multivariate logistical regression analysis was done to assess for the association between preoperative factors and allogeneic blood product use.

RESULTS

A total of 1595 patients were included in this study, of which 1488 underwent a Coronary Artery Bypass Graft, Valve or a combined procedure. Patients on dialysis preoperatively and those who had preoperative cardiogenic shock demonstrated the greatest risk of requiring RBC transfusion with an odds ratio of 5.643 (95% CI 1.305-24.40) and 3.257 (95% 1.801-5.882) respectively. Patients who had preoperative cardiogenic shock demonstrated the greatest risk of requiring NRBC transfusion with an odds ratio of 3.473 (95% CI 1.970-6.135). Patients who have had a previous cardiothoracic intervention are at increased risk of both RBC and NRBC transfusion, with adjusted odds ratios of 1.774 (95% CI 1.353-2.325) and 2.370 (95% CI 1.748-3.215) respectively.

CONCLUSION

A number of factors relating to past medical history or preoperative cardiac status are implicated with increased allogeneic blood product use in cardiac surgery. Identifying high-risk patients in a preoperative setting can enable us enrol them in a blood conservation program, therefore minimizing the risk of exposure to blood transfusion.

Growth of Physicians and Nurse Practitioners Practicing Full Time in Nursing Homes

OBJECTIVES

The objective was to describe the growth of physicians, nurse practitioners (NPs), and physician assistants (PAs) who practice full time in nursing homes, to assess resident and nursing home characteristics associated with receiving care from full-time providers, and describe variation among nursing homes in use of full-time providers.

DESIGN

Retrospective cohort study.

SETTING AND PARTICIPANTS

A 20% national sample Medicare data on long-term care residents in 2008 to 2018 and the physicians, NPs, and PAs who submitted charges to Medicare for their care.

METHODS

We measured the percentage of provider charges for services rendered in nursing homes, in addition to resident and facility characteristics.

RESULTS

Full-time nursing home providers increased from 26.0% of all nursing home providers in 2008 to 44.6% in 2017. The largest increase was in NPs: from 1986 in 2008 to 4479 in 2017. Resident age, sex, Medicaid eligibility, and race/ethnicity had minimal association with the odds of having a full-time provider, whereas residents with an NP primary care provider were 23.0 times more likely (95% confidence interval = 21.6, 24.6) to have a full-time provider. Residents who received care from both a physician and an NP or PA increased from 33.6% in 2008 to 62.5% in 2018. There was large variation among facilities in the percentage of residents with full-time providers, from 5.72% of residents with full-time providers in the bottom quintile of facilities to 91.44% in the top quintile. Individual nursing homes accounted for 59% of the variation in whether a resident had a full-time provider.

CONCLUSIONS AND IMPLICATIONS

The percentage of nursing home residents with full-time providers continues to grow, with very large variation among nursing homes.

Optimising bloodless cardiovascular surgery for Jehovah's Witnesses and beyond

Emerging evidence suggests surgical outcomes of patients undergoing cardiovascular surgery that refuse autologous transfusion is comparable to those who accept whole blood product transfusions. There are several methods that can be used to minimize blood loss during cardiovascular surgery. These methods can be categorised into pharmacological measures, including the use of erythropoietin, iron and tranexamic acid, surgical techniques, like the use of polysaccharide haemostat, and devices such as those used in acute normovolaemic haemodilution. More prospective studies with stricter protocols are required to assess surgical outcomes in bloodless cardiac surgery as well as further research into the long-term outcomes of bloodless cardiovascular surgery patients. This review summarizes current evidence on the use of pre-, intra-, and post-operative strategies aimed at the subset of patients who refuse blood transfusion, for example Jehovah's Witnesses.

Machine learning models to predict red blood cell transfusion in patients undergoing mitral valve surgery

Background

Red blood cell (RBC) transfusion therapy has been widely used in surgery, and has yielded excellent treatment outcomes. However, in some instances, the demand for RBC transfusion is assessed by doctors based on their experience. In this study, we use machine learning models to predict the need for RBC transfusion during mitral valve surgery to guide the surgeon's assessment of the patient's need for intraoperative blood transfusion.

Methods

We retrospectively reviewed 698 cases of isolated mitral valve surgery with and without combined tricuspid valve operation. Seventy percent of the database was used as the training set and the remainder as the testing set for 13 machine learning algorithms to build a model to predict the need for intraoperative RBC transfusion. According to the characteristic value of model mining, we analyzed the risk-related factors to determine the main effects of variables influencing the outcome.

Results

A total of 166 patients of the cases considered had undergone intraoperative RBC transfusion (24.52%). Of the 13 machine learning algorithms, CatBoost delivered the best performance, with an AUC of 0.888 (95% CI: 0.845-0.909) in testing set. Further analysis using the CatBoost model revealed that hematocrit (<37.81%), age (>64 y), body weight (<59.92 kg), body mass index (BMI) (<22.56 kg/m²), hemoglobin (<122.6 g/L), type of surgery (median thoracotomy surgery), height (<160.61 cm), platelet (>194.12×10⁹/L), RBC (<4.08×10¹²/L), and gender (female) were the main risk-related factors for RBC transfusion. A total of 204 patients were tested, 177 of whom were predicted accurately (86.8%).

Conclusions

Machine learning models can be used to accurately predict the outcomes of RBC transfusion, and should be used to guide surgeons in clinical practice.

Periodontitis increases risk of viable bacteria in freshly drawn blood donations

BACKGROUND

The aim of the study was to determine if periodontitis, which often causes transient bacteraemia, associates with viable bacteria in standard blood donations.

MATERIALS AND METHODS

This was a cross-sectional study of 60 self-reported medically healthy blood donors aged over 50 years. According to standard procedures, whole blood was separated by fractionation into plasma, buffy-coat, and red blood cell (RBC)-fractions. The buffy-coat was screened for bacterial contamination using BacT/ALERT. Samples from plasma and RBC-fractions were incubated anaerobically and aerobically at 37°C for 7 days on trypticase soy blood agar (TSA). For identification, colony polymerase chain reaction was performed using primers targeting 16S rDNA.

RESULTS

From 62% of the donors with periodontitis, bacterial growth was observed on at least 1 out of 4 plates inoculated with plasma or RBCs, whereas only 13% of plates inoculated with plasma or RBCs from periodontally healthy controls yielded bacterial growth (relative risk 6.4, 95% CI: 2.1; 19.5; p=0.0011). None of the donors tested positive for bacterial contamination using BacT/ALERT. Cutibacterium acnes was found in 31% of the donations from donors with periodontitis and in 10% of the donations from periodontally healthy donors. In addition, Staphylococcus species, Bacillus mycoides, Aggregatibacter aphrophilus, and Corynebacterium kroppenstedtii were detected.

DISCUSSION

Periodontitis increased the risk of bacterial contamination of blood products. Contaminating bacteria are often associated with the RBC-fraction. As the BacT/ALERT test is generally performed on platelet products, routine screening fails to detect many occurrences of viable bacteria in the RBC-fraction.

Retrospective Analysis of Thromboelastography-Directed Transfusion in Isolated CABG: Impact on Blood Product Use, Cost, and Outcomes

Cardiac surgeries account for approximately 20% of blood use in the United States. Allogeneic transfusion has been associated with increased risk of morbidity and mortality, further justifying the need to reduce blood use. This study aimed at determining whether a point-of-care coagulation test, thromboelastography (TEG), impacted blood product administration and outcomes. Patients undergoing isolated coronary artery bypass grafting (CABG) were retrospectively reviewed before the use of TEG (2008-2009) (n = 640) and after implementation (2011-2012) (n = 458). Blood product use was compared between time frames. Logistic regression and generalized linear models were created to estimate the impact on outcomes including the reoperation rate, mortality, and cost. The mean use of each blood product was significantly reduced in the perioperative period. Overall blood product use was decreased by over 40%. Mediastinal re-exploration of bleeding was significantly reduced with TEG (4.8 vs. 1.5%). Six-month mortality was not impacted in this cohort nor was the readmission rate or hospital length of stay. However, blood cost and patient charges were significantly lower after TEG was introduced. The use of TEG to guide the administration of blood products during isolated CABG significantly affected the amounts and types of products given intra- and perioperatively. This resulted in less chest tube drainage, fewer returns to the operating room, and more accurate diagnosis of coagulopathic status. Cost savings to the patient and institution were appreciated as a consequence of these improved clinical outcomes.

Evolution of perioperative blood transfusion practice after coronary artery bypass grafting in the past two decades

BACKGROUND AND AIM OF THE STUDY

Transfusion of blood products after coronary artery bypass grafting (CABG) is associated with increased morbidity and mortality. We evaluated the perioperative use of blood products in patients undergoing CABG in our institution over the past two decades.

METHODS

The study included 18 992 patients who underwent isolated CABG at our hospital between 1998 and 2017. Baseline characteristics of patients and the number of perioperative transfusions during their hospital stay (including red blood cells [RBCs], platelets, and fresh frozen plasma [FFP]) were assessed. Logistic regression models were used to identify risk factors for perioperative transfusion.

RESULTS

The rates of perioperative RBC transfusion decreased for all patients undergoing isolated CABG (52.1% in 1998 vs 18.6% in 2017) in our institution. The mean number of transfused RBC units was significantly higher in women than in men (1.57 ± 2.2 vs 0.68 ± 1.84; P < .005); this difference remained significant over the years. After adjusting the results for other risk factors, female sex was a significant independent risk factor for perioperative RBC transfusion. The platelet transfusion rate increased over the past two decades (1.4% in 1998 vs 9.7% in 2017). The number of FFP transfusions remained unchanged.

CONCLUSIONS

Over the past two decades, we observed a decrease in the incidence of perioperative RBC transfusions in patients undergoing isolated CABG, whereas platelet transfusions increased. Female sex was an independent predictor of perioperative RBC transfusion.

Assessment of the knowledge level of the professional as regards Patient Blood Management in their organisation. Results of the MAPBM project survey

INTRODUCTION

The Maturity Assessment Model in Patient Blood Management project involves the use of a matrix that evaluates the maturity of the centre as regards blood transfusion practice. This tool includes a questionnaire to be completed by physicians to determine their level of knowledge of patient blood management strategies in their centre.

MATERIAL AND METHODS

Forty one hospitals took part in the Maturity Assessment Model in Patient Blood Management project in 2016. The questionnaire included 10 questions, 3 about the centre, specialty, and years of experience, and 7 about patient blood management protocols in the respondent's centre. The minimum responses required per centre was calculated according to the number of beds. Responses from at least 3 different specialties were required in order to be evaluated.

RESULTS

A total of 1403 questionnaires were completed. The specialty with the highest completion rate was anaesthesiology (40.9%). The distribution as regards professional experience was homogeneous: <10 years, 33.4%, 10-20 years, 33%, and> 20 years 33.6%. Nearly three-quarters (74.2%) knew the patient blood management protocol used in their centre, and 60.7% knew the protocol for the treatment of pre-operative anaemia. Slightly fewer (72%) reported knowing the blood transfusion protocol (transfusion threshold) used in their centre, and 90% considered other factors besides haemoglobin in the decision to transfuse. Only 30.7% of professionals reported receiving periodic information on transfusion practices.

CONCLUSIONS

There is a significant lack of knowledge about preoperative anaemia and perioperative transfusion protocols used in the centres polled. Few centres provide their physicians with information on transfusion practices.

Clinical Features and Outcomes of Peripheral Vascular Disease Patients Receiving Red Blood Cell Transfusions

Background Peripheral vascular disease (PVD) patients are commonly transfused with red blood cells (RBC) due to their inability to compensate for anemia and blood loss. Anemias, as well as allogeneic transfusions, have been demonstrated as independent risk factors for increased mortality and morbidity following cardiovascular procedures. The relationships between anemia, transfusion, and adverse outcomes in PVD patients remain unascertained and understudied. Methods A retrospective cohort study was conducted to determine mortality at 30-day, one-year, and three-year markers among 330 randomly selected PVD patients. The clinical features of patients receiving transfusions were examined, and the mortality rates were compared between patients who received an RBC transfusion and those who did not. Cox regression analysis was employed to identify independent variables predicting mortality. Results Transfusions were found to have increased mortality rates over non-transfused patients at 30 days (6.1% vs. 1.8%, p = 0.05), one year (21.8% vs 12.1%, p = 0.02), and three years (41.2% vs. 23.0%, p = 0.001). Using a multivariate regression model, it was determined that the transfusion itself was not a significant cause of this decrease in survival, while the propensity to transfuse was a predictor for both short (30 days, 36.73 [1.85-728.06], p = 0.04) and long-term mortality (one year (8.83 [2.62-29.77], p < 0.001; three years (7.07 [1.46-8.07], p <0.01). Anti-coagulation therapy using intravenous (IV) heparin and the chronic comorbidities of coronary artery disease and diabetes mellitus were also robust independent predictors of decreased survival. Conclusion This study was able to find an association between RBC transfusion and reduction in short-term (three months) and long-term (three years) survival. Those requiring IV heparin during the hospital stay were at an increased risk of requiring blood transfusion, and patients receiving IV heparin were also found to have a significant increase in mortality rates.

Association of Primary Hemodilution and Retrograde Autologous Priming with Transfusion in Cardiac Surgery: Analysis of the Perfusion Case Database of the Japanese Society of Extra-Corporeal Technology in Medicine

It is important to avoid unnecessary blood cell transfusion. However, the associations of hemodilution and retrograde autologous priming with red blood cell transfusion during and after cardiopulmonary bypass (CPB) in cardiac surgery in Japan are currently unclear. We analyzed these associations using data for 3,090 adults from the Perfusion Case Database of the Japanese Society of Extra-Corporeal Technology in Medicine. Percent hemodilution was calculated by total priming volume and weight. Logistic regression models were used to adjust for covariates including type of surgery, gender, age, hemoglobin concentration before CPB, CPB time, urine volume during CPB, and institution. The percentages of red blood cell transfusions during CPB for patients with <15, 15 to <20, 20 to <25, 25 to <30, and ≥30% hemodilution were 43.0, 51.5, 68.9, 77.3, and 87.7%, respectively. This increase in line with increasing dilution was significant after adjusting for covariates. The percentage of red blood cell transfusion after CPB also increased slightly between 39.0 and 49.4% with percent hemodilution, but the trend after adjusting for covariates was not significant. Use of retrograde autologous priming was significantly associated with blood cell transfusion during CPB after adjusting for covariates, but was not significantly related to blood cell transfusion after CPB. These results suggest that optimizing the percent hemodilution and use of retrograde autologous priming might reduce the use of red blood cell transfusion during CPB in clinical practice in Japan.

Hospital variability of postoperative sepsis and sepsis-related mortality after elective coronary artery bypass grafting surgery

PURPOSE

Hospital variability of postoperative sepsis and sepsis-related mortality after elective CABG surgery was not known in Australia.

MATERIAL AND METHODS

Population-based analysis of all elective patients who underwent CABG surgery in public and private hospitals between 2007 and 2014 using linked data from the state-wide Admitted Patient Data Collection and the NSW Registry of Births, Deaths, and Marriages.

RESULTS

We identified 18,928 (9464 pairs) matched patients who had elective CABG surgery in public hospitals (n = 9) and private hospitals (n = 13) during the study period. When compared to public hospital patients, private hospital patients had a significantly lower rate of post-CABG sepsis (13.3 vs 20.4 per 1000 admissions, P < 0.001; treatment effects: -7.1, 95%CI: -11.1 to -3.3), a lower in-hospital mortality rate (6.1 vs 9.9 per 1000 admissions, P = 0.006; treatment effects: -3.8, 95%CI: -6.5 to -1.1), and a lower rate of 30-day readmission (11.9% vs 13.9%, P < 0.001; treatment effects: -2.0%, 95%CI: -3.1% to -1.0%). In addition, for both public and private hospital groups, there were significant differences for all outcomes when comparing the worst and best performance quintile hospitals.

CONCLUSIONS

Hospital variability of postoperative sepsis, in-hospital mortality and readmission after elective CABG existed between and within public and private hospitals.

Preoperative Mechanical Bowel Evacuation Reduces Intraoperative Bleeding and Operation Time in Spinal Surgery

Study Design

Randomized clinical trial.

Purpose

In this study, we evaluated the effect of mechanical evacuation of the bowels prior to operation on intraoperative bleeding.

Overview of Literature

Bleeding is the most significant complication in patients undergoing spinal surgery.

Methods

We randomly divided 108 individuals planned to undergo spinal surgery into two age-, sex-, and co-morbidity (especially preoperative hemoglobin [Hb])-matched groups of 54. The treatment group was administered polyethylene glycol (PEG) before the operation, whereas the control group was not. The exact amount (mL) of bleeding during operation, operative time, and approximate amount of blood transfused were recorded. The volume of bleeding and Hb level were also recorded 24 and 48 hours postoperatively.

Results

T-tests revealed that intraoperative bleeding, the volume of transfusion, and operative time were significantly lower in the treatment group than in the control group. Statistically significant correlations of intraoperative bleeding with age, body mass index (BMI), preoperative Hb levels, operative time, the volume of transfusion, hospitalization time, and 24- and 48-hour postoperative bleeding were observed (p =0.001, all). Repeated measures analysis of covariance after adjusting the covariate variables revealed that the volume of bleeding showed a near-significant trend in the treatment group compared with that in the control group (p =0.056). Diabetic females had the highest bleeding amount between the groups (p =0.03). Bleeding was higher in patients with higher BMI (p =0.02) and was related to operative time (p =0.001) in both the groups.

Conclusions

Preoperative gastrointestinal tract evacuation by PEG administration can decrease intraoperative bleeding in spinal surgeries; however, more research is imperative regarding PEG administration in surgical procedures for this purpose.

Preoperative anemia versus blood transfusion: Which is the culprit for worse outcomes in cardiac surgery?

BACKGROUND

Reducing blood product utilization after cardiac surgery has become a focus of perioperative care as studies have suggested improved outcomes. The relative impact of preoperative anemia versus packed red blood cells (PRBC) transfusion on outcomes remains poorly understood, however. In this study, we investigated the relative association between preoperative hematocrit (Hct) level and PRBC transfusion on postoperative outcomes after coronary artery bypass grafting (CABG) surgery.

METHODS

Patient records for primary, isolated CABG operations performed between January 2007 and December 2017 at 19 cardiac surgery centers were evaluated. Hierarchical logistic regression modeling was used to estimate the relationship between baseline preoperative Hct level as well as PRBC transfusion and the likelihoods of postoperative mortality and morbidity, adjusted for baseline patient risk. Variable and model performance characteristics were compared to determine the relative strength of association between Hct level and PRBC transfusion and primary outcomes.

RESULTS

A total of 33,411 patients (median patient age, 65 years; interquartile range [IQR], 57-72 years; 26% females) were evaluated. The median preoperative Hct value was 39% (IQR, 36%-42%), and the mean Society of Thoracic Surgeons (STS) predicted risk of mortality was 1.8 ± 3.1%. Complications included PRBC transfusion in 31% of patients, renal failure in 2.8%, stroke in 1.3%, and operative mortality in 2.0%. A strong association was observed between preoperative Hct value and the likelihood of PRBC transfusion (P < .001). After risk adjustment, PRBC transfusion, but not Hct value, demonstrated stronger associations with postoperative mortality (odds ratio [OR], 4.3; P < .0001), renal failure (OR 6.3; P < .0001), and stroke (OR, 2.4; P < .0001). A 1-point increase in preoperative Hct was associated with decreased probabilities of mortality (OR, 0.97; P = .0001) and renal failure (OR, 0.94; P < .0001). The models with PRBC had superior predictive power, with a larger area under the curve, compared with Hct for all outcomes (all P < .01). Preoperative anemia was associated with up to a 4-fold increase in the probability of PRBC transfusion, a 3-fold increase in renal failure, and almost double the mortality.

CONCLUSIONS

PRBC transfusion appears to be more closely associated with risk-adjusted morbidity and mortality compared with preoperative Hct level alone, supporting efforts to reduce unnecessary PRBC transfusions. Preoperative anemia independently increases the risk of postoperative morbidity and mortality. These data suggest that preoperative Hct should be included in the STS risk calculators. Finally, efforts to optimize preoperative hematocrit should be investigated as a potentially modifiable risk factor for mortality and morbidity.

Organizational Contributors to the Variation in Red Blood Cell Transfusion Practices in Cardiac Surgery: Survey Results From the State of Michigan

BACKGROUND

While large volumes of red blood cell transfusions are given to preserve life for cardiac surgical patients, indications for lower volume transfusions (1-2 units) are less well understood. We evaluated the relationship between center-level organizational blood management practices and center-level variability in low volume transfusion rates.

METHODS

All 33 nonfederal, Michigan cardiac surgical programs were surveyed about their blood management practices for isolated, nonemergent coronary bypass procedures, including: (1) presence and structure of a patient blood management program, (2) policies and procedures, and (3) audit and feedback practices. Practices were compared across low (N = 14, rate: 0.8%-10.1%) and high (N = 18, rate: 11.0%-26.3%) transfusion rate centers.

RESULTS

Thirty-two (97.0%) of 33 institutions participated in this study. No statistical differences in organizational practices were identified between low- and high-rate groups, including: (1) the membership composition of patient blood management programs among those reporting having a blood management committee (P= .27-1.0), (2) the presence of available red blood cell units within the operating room (4 of 14 low-rate versus 2 of 18 high-rate centers report that they store no units per surgical case, P= .36), and (3) the frequency of internal benchmarking reporting about blood management audit and feedback practices (low rate: 8 of 14 versus high rate: 9 of 18; P= .43).

CONCLUSIONS

We did not identify meaningful differences in organizational practices between low- and high-rate intraoperative transfusion centers. While a larger sample size may have been able to identify differences in organizational practices, efforts to reduce variation in 1- to 2-unit, intraoperative transfusions may benefit from evaluating other determinants, including organizational culture and provider transfusion practices.

Mild volume acute normovolemic hemodilution is associated with lower intraoperative transfusion and postoperative pulmonary infection in patients undergoing cardiac surgery -- a retrospective, propensity matching study

Background

Perioperative allogenic transfusion is required in almost 50% of patients undergoing cardiac surgery and is associated with higher risk of mortality and morbidity (Xue et al., Lancet 387:1905, 2016; Ferraris et al., Ann Thorac Surg 91:944–82, 2011). Acute normovolemic hemodilution (ANH) is recommended as a potential strategy during cardiac surgery, but the blood conservation effect and the degree of ANH was still controversial. There is also an increasing concern about the improved outcomes associated with ANH. Therefore, a better understanding of the effect of mild volume ANH during cardiac surgery is urgently needed.

Methods

This retrospective study included 2058 patients who underwent cardiac surgery between 2010 and 2015. The study population was split into two groups (with and without mild volume ANH). Propensity score adjustment analysis was applied. We reported the association between the use of mild volume ANH and perioperative outcomes.

Results

A total of 1289 patients were identified. ANH was performed in 358 patients, and the remaining 931 patients did not receive any ANH. Five hundred of the total patients (38.8%) received perioperative RBC transfusions, 10% (129/1289) of patients received platelet, and 56.4% (727/1289) of patients received fresh frozen plasma transfusions. Mild volume ANH administration was significantly associated with decreased intraoperative RBC transfuse rate (8.5% vs. 14.4%; p = 0.013), number of RBC units (p = 0.019), and decreased postoperative pulmonary infection (6.8 vs. 11.3%; p = 0.036) during cardiac surgery. However, there was no significant difference regarding intraoperative fresh frozen plasma (FFP) and platelet concentrate transfusions, as well as postoperative and total perioperative allogeneic transfusions. Furthermore, there was no significant difference regarding postoperative outcomes including mortality, prolonged wound healing, stroke, atrial fibrillation, reoperation for postoperative bleeding and acute kidney injury. There was also no difference in postoperative ventilation time, length of ICU and hospital stay.

Conclusion

Based on the 5-year experience of mild volume ANH in cardiac surgeries with CPB in our large retrospective cohort, mild volume ANH was associated with decreased intraoperative RBC transfusion and postoperative pulmonary infection in Chinese patients undergoing cardiac surgery. However, there was no significant difference regarding postoperative and total perioperative allogeneic transfusions.

Electronic supplementary material

The online version of this article (doi:10.1186/s12871-017-0305-7) contains supplementary material, which is available to authorized users.

Rethinking Thirty-Day Hospital Readmissions: Shorter Intervals Might Be Better Indicators Of Quality Of Care

Public reporting and payment programs in the United States have embraced thirty-day readmissions as an indicator of between-hospital variation in the quality of care, despite limited evidence supporting this interval. We examined risk-standardized thirty-day risk of unplanned inpatient readmission at the hospital level for Medicare patients ages sixty-five and older in four states and for three conditions: acute myocardial infarction, heart failure, and pneumonia. The hospital-level quality signal captured in readmission risk was highest on the first day after discharge and declined rapidly until it reached a nadir at seven days, as indicated by a decreasing intracluster correlation coefficient. Similar patterns were seen across states and diagnoses. The rapid decay in the quality signal suggests that most readmissions after the seventh day postdischarge were explained by community- and household-level factors beyond hospitals' control. Shorter intervals of seven or fewer days might improve the accuracy and equity of readmissions as a measure of hospital quality for public accountability.

Point-of-care platelet function testing to predict blood loss after coronary artery bypass grafting surgery: a prospective observational pilot study

Aim:

With an increase in the number of patients who are on antiplatelet medications until the day of surgery, we undertook a prospective observational study to assess the ability of thromboelastography, thromboelastography platelet mapping and aggregometry via multiplate to detect platelet dysfunction and predict blood loss following coronary artery bypass grafting (CABG) surgery.

Methods:

Platelet function was evaluated pre- and post-cardiopulmonary bypass via thromboelastography, thromboelastography platelet mapping and aggregometry via multiplate in 52 patients undergoing coronary artery bypass grafting surgery. The median chest tube drainage of all patients in the study was ascertained to stratify patients into two groups: patients with and those without evidence of excessive blood loss after cardiac surgery.

Results:

Although all modalities could detect a decrease in platelet function following cardiopulmonary bypass, univariate and multivariate regression analysis identified preoperative arachidonic acid and adenosine diphosphate testing via multiplate as independent predictors of bleeding after cardiac surgery. Receiver operating curves on these multiplate parameters showed an area under the curve of 0.68 (p=0.03) and 0.66 (p=0.01) for arachidonic acid and adenosine diphosphate assays, respectively.

Conclusion:

This pilot study shows that preoperative multiplate testing may be a better predictor of platelet dysfunction and the resultant blood loss following cardiac surgery.

Anemia in Intensive Cardiac Care Unit patients - An underestimated problem

The heterogeneous group of patients admitted to Intensive Cardiac Care Unit (ICCU) as well as nonspecific complaints associated with anemia might be the reason for underdiagnosing or minimization of this problem. Because of this heterogeneity, there are no clear guidelines to follow. It is known that anemia is impairing the outcome. Thus, it is crucial to keep alert in the diagnosis and treatment of anemia, especially in critically ill cardiac patients. The greatest groups of patients admitted to ICCU are those with acute coronary syndromes (ACS), acute decompensated heart failure (ADHF), severe arrhythmias as well as individuals after cardiac operations. However, patients suffering other critical cardiac illnesses quite often become anemic during hospitalization in ICCU. It is because anemia is typed in the clinical features of heavy diseases or may be the consequence of treatment. The current review focuses on the incidence, complex etiology and predictive role of anemia in a diverse group of ICCU patients. It discusses clinical aspects of anemia treatment in particular groups of critically ill cardiac patients because proper treatment increases chances for recovery and improves the outcome in this severe group of patients.

Sources of Variation in Hospital-Level Infection Rates After Coronary Artery Bypass Grafting: An Analysis of The Society of Thoracic Surgeons Adult Heart Surgery Database

BACKGROUND

Patients undergoing coronary artery bypass grafting (CABG) are at risk for a variety of infections. Investigators have focused on predictors of these adverse sequelae, but less attention has been focused on characterizing hospital-level variability in these outcomes.

METHODS

Between July 2011 and December 2013, The Society of Thoracic Surgeons Adult Cardiac Surgery Database shows 365,686 patients underwent isolated CABG in 1,084 hospitals. Hospital-acquired infections (HAIs) were defined as pneumonia, sepsis/septicemia, deep sternal wound infection/mediastinitis, vein harvest/cannulation site infection, or thoracotomy infection. Hospitals were ranked by their HAI rate as low (≤ 10th percentile), medium (10th to 90th percentile), and high (>90th percentile). Differences in perioperative factors and composite morbidity and mortality end points across these groups were determined using the Wilcoxon rank sum and χ(2) tests.

RESULTS

HAIs occurred among 3.97% of patients overall, but rates varied across hospital groups (low: <0.84%, medium: 0.84% to 8.41%, high: >8.41%). Pneumonia (2.98%) was the most common HAI, followed by sepsis/septicemia (0.84%). Patients at high-rate hospitals more often smoked, had diabetes, chronic lung disease, New York Heart Association Functional Classification III to IV, and received blood products (p < 0.001); however, they less often were prescribed the appropriate antibiotics (p < 0.001). Major morbidity and mortality occurred among 12.3% of patients, although this varied by hospital group (low: 8.6%, medium: 12.3%, high: 17.9%; p < 0.001).

CONCLUSIONS

Substantial hospital-level variation exists in postoperative HAIs among patients undergoing CABG, driven predominantly by pneumonia. Given the relatively small absolute differences in comorbidities across hospital groups, our findings suggest factors other than case mix may explain the observed variation in HAI rates.

Postoperative Critical Care of the Adult Cardiac Surgical Patient. Part I: Routine Postoperative Care

OBJECTIVES

Cardiac surgery, including coronary artery bypass, cardiac valve, and aortic procedures, is among the most common surgical procedures performed in the United States. Successful outcomes after cardiac surgery depend on optimum postoperative critical care. The cardiac intensivist must have a comprehensive understanding of cardiopulmonary physiology and the sequelae of cardiopulmonary bypass. In this concise review, targeted at intensivists and surgeons, we discuss the routine management of the postoperative cardiac surgical patient.

DATA SOURCE AND SYNTHESIS

Narrative review of relevant English-language peer-reviewed medical literature.

CONCLUSIONS

Critical care of the cardiac surgical patient is a complex and dynamic endeavor. Adequate fluid resuscitation, appropriate inotropic support, attention to rewarming, and ventilator management are key components. Patient safety is enhanced by experienced personnel, a structured handover between the operating room and ICU teams, and appropriate transfusion strategies.

Surgeon and Facility Variation in the Use of Minimally Invasive Breast Biopsy in Texas

OBJECTIVE AND BACKGROUND

Minimally invasive breast biopsy (MIBB) rates remain well below guideline recommendations of more than 90% and vary across geographic areas. Our aim was to determine the variation in use attributable to the surgeon and facility and determine the patient, surgeon, and facility characteristics associated with the use of MIBB.

METHODS

We used 100% Texas Medicare claims data (2000-2008) to identify women older than 66 years with a breast biopsy (open or minimally invasive) and subsequent breast cancer diagnosis/operation within 1 year. The percentage of patients undergoing MIBB as the first diagnostic modality was estimated for each surgeon and facility. Three-level hierarchical generalized linear models (patients clustered within surgeons within facilities) were used to evaluate variation in MIBB use.

RESULTS

A total of 22,711 patients underwent a breast cancer operation by 1226 surgeons at 525 facilities. MIBB was the initial diagnostic modality in 62.4% of cases. Only 7.0% of facilities and 12.9% of surgeons used MIBB for more than 90% of patients. In 3-level models adjusted for patient characteristics, the percentage of patients who received MIBB ranged from 7.5% to 96.0% across facilities (mean = 50.1%, median = 49.2%) and from 8.0% to 87.0% across surgeons (mean = 50.3%, median = 50.9%). The variance in MIBB use was attributable to facility (8.8%) and surgeon (15.4%) characteristics. Lower surgeon and facility volume, longer surgeon years in practice, and smaller facility bed size were associated with lower rates of MIBB use.

CONCLUSIONS

Identification of surgeon and facility characteristics associated with low use of MIBB provides potential targets for interventions to improve MIBB rates and decrease variation in use.

TYPE OF STUDY

Retrospective cohort.

Red Blood Cell Transfusions Impact Pneumonia Rates After Coronary Artery Bypass Grafting

BACKGROUND

Pneumonia, a known complication of coronary artery bypass grafting (CABG), significantly increases a patient's risk of morbidity and mortality. Although not well characterized, red blood cell (RBC) transfusions may increase a patient's risk of pneumonia. We describe the relationship between RBC transfusion and postoperative pneumonia after CABG.

METHODS

A total of 16,182 consecutive patients underwent isolated CABG between 2011 and 2013 at 1 of 33 hospitals in the state of Michigan. We used multivariable logistic regression to estimate the relative odds of pneumonia associated with the use or number of RBC units (0, 1, 2, 3, 4, 5, and ≥ 6). We adjusted for predicted risk of mortality, preoperative hematocrit values, history of pneumonia, cardiopulmonary bypass duration, and medical center. We confirmed the strength and direction of these relationships among selected clinical subgroups in a secondary analysis.

RESULTS

Five hundred seventy-six (3.6%) patients had pneumonia and 6,451 (39.9%) received RBC transfusions. There was a significant association between any RBC transfusion and pneumonia (adjusted odds ratio [ORadj], 3.4; p < 0.001). There was a dose response between number of units and odds of pneumonia, with a ptrend less than 0.001. Patients receiving only 2 units of RBCs had a 2-fold (ORadj, 2.1; p < 0.001) increased odds of developing pneumonia. These findings were consistent across clinical subgroups.

CONCLUSIONS

We found a significant volume-dependent association between an increasing number of RBCs and the odds of pneumonia, which persisted after risk adjustment. Clinical teams should explore opportunities for preventing a patient's risk of RBC transfusions, including reducing hemodilution or adopting a lower transfusion threshold in a stable patient.

Risk Factors for Urinary Tract Infections in Cardiac Surgical Patients

BACKGROUND

Risk factors for catheter-associated urinary tract infections (CAUTIs) in patients undergoing non-cardiac surgical procedures have been well documented. However, the variables associated with CAUTIs in the cardiac surgical population have not been clearly defined. Therefore, the purpose of this study was to investigate risk factors associated with CAUTIs in patients undergoing cardiac procedures.

METHODS

All patients undergoing cardiac surgery at a single institution from 2006 through 2012 (4,883 patients) were reviewed. Patients with U.S. Centers for Disease Control (CDC) criteria for CAUTI were identified from the hospital's Quality Assessment database. Pre-operative, operative, and post-operative patient factors were evaluated. Univariate and multivariable analyses were used to identify significant correlations between perioperative characteristics and CAUTIs.

RESULTS

There were 55 (1.1%) documented CAUTIs in the study population. On univariate analysis, older age, female gender, diabetes mellitus, cardiogenic shock, urgent or emergent operation, packed red blood cell (PRBC) units transfused, and intensive care unit length of stay (ICU LOS) were all significantly associated with CAUTI [p<0.05]. On multivariable logistic regression, older age, female gender, diabetes mellitus, and ICU LOS remained significantly associated with CAUTI. Additionally, there was a significant association between CAUTI and 30-d mortality on univariate analysis. However, when controlling for common predictors of operative mortality on multivariable analysis, CAUTI was no longer associated with mortality.

CONCLUSIONS

There are several identifiable risk factors for CAUTI in patients undergoing cardiac procedures. CAUTI is not independently associated with increased mortality, but it does serve as a marker of sicker patients more likely to die from other comorbidities or complications. Therefore, awareness of the high-risk nature of these patients should lead to increased diligence and may help to improve peri-operative outcomes. Recognizing patients at high risk for CAUTI may lead to improved measures to decrease CAUTI rates within this population.

Viable bacteria associated with red blood cells and plasma in freshly drawn blood donations

Objectives

Infection remains a leading cause of post-transfusion mortality and morbidity. Bacterial contamination is, however, detected in less than 0.1% of blood units tested. The aim of the study was to identify viable bacteria in standard blood-pack units, with particular focus on bacteria from the oral cavity, and to determine the distribution of bacteria revealed in plasma and in the red blood cell (RBC)-fraction.

Design

Cross-sectional study. Blood were separated into plasma and RBC-suspensions, which were incubated anaerobically or aerobically for 7 days on trypticase soy blood agar (TSA) or blue lactose plates. For identification colony PCR was performed using primers targeting 16S rDNA.

Setting

Blood donors attending Capital Region Blood Bank, Copenhagen University Hospital, Rigshospitalet, Hvidovre, Denmark, October 29^th to December 10^th 2013.

Participants

60 donors (≥50 years old), self-reported medically healthy.

Results

Bacterial growth was observed on plates inoculated with plasma or RBCs from 62% of the blood donations. Growth was evident in 21 (35%) of 60 RBC-fractions and in 32 (53%) of 60 plasma-fractions versus 8 of 60 negative controls (p = 0.005 and p = 2.6x10^-6, respectively). Propionibacterium acnes was found in 23% of the donations, and Staphylococcus epidermidis in 38%. The majority of bacteria identified in the present study were either facultative anaerobic (59.5%) or anaerobic (27.8%) species, which are not likely to be detected during current routine screening.

Conclusions

Viable bacteria are present in blood from donors self-reported as medically healthy, indicating that conventional test systems employed by blood banks insufficiently detect bacteria in plasma. Further investigation is needed to determine whether routine testing for anaerobic bacteria and testing of RBC-fractions for adherent bacteria should be recommended.

Risk factors related to transfusion requirements in patients undergoing implantation of ventricular assist devices

OBJECTIVE

The identification of transfusion risk factors in patients receiving left ventricular assist devices to allow for targeted use of blood conservation strategies and improved blood utilization.

DESIGN

This is a retrospective analysis of prospectively collected data between April 2009 and June 2012. Linear regression was used to determine factors associated with increased transfusion. Logistic regression was used to determine factors that were associated with more than the median number of units transfused.

SETTING

Single center, university hospital.

PARTICIPANTS

Patients (n=144) who underwent left ventricular assist device implantation.

INTERVENTION

Transfused blood product data for the day of surgery and for 3 days after were obtained from the blood bank.

MEASUREMENTS AND MAIN RESULTS

Beta-blockers were associated with 1.7±0.65 fewer red blood cell (RBC) units and 2.2±0.7 fewer fresh frozen plasma units transfused. Each year of older age was associated with 0.113±0.023 units of RBC, 0.543±0.101 platelet, and 0.098±0.017 plasma units transfused. International normalized ratio was associated with more platelet transfusion (20.813±5.757 units per 1.0 increase), but not with plasma or RBC transfusion. Lower platelet counts were associated with both platelet (-0.045±0.019 units per 10,000 μL(-1)) and plasma transfusions (-0.011±0.004). Myocardial infarction was associated with increased RBC and plasma transfusion, and cardiogenic shock was associated with increased platelet transfusions, but nitrate use was associated with reduced platelet transfusion.

CONCLUSION

Beta-blockers may be a modifiable factor to decrease transfusions. The association between international normalized ratio and platelet transfusions suggests that better determination of the type of coagulopathy may promote more appropriate transfusions.

Hemoglobin Level to Facilitate Off-Pump Coronary Artery Bypass without Transfusion

BACKGROUND

Conservation of blood during cardiac surgery is important because of the shortage of donor blood, risks associated with transfusion, and the costs of allogeneic blood products. This retrospective study explored the feasibility of off-pump coronary artery bypass (OPCAB) without transfusion.

METHODS

One hundred and two consecutive patients underwent OPCAB from January 2007 to June 2012 at Hallym University Sacred Heart Hospital. Excluding 10 chronic renal failures patients, 102 patients were enrolled. Their characteristics, clinical data, and laboratory data were analyzed. We investigated the success rate of OPCAB without transfusion according to pre-operative hemoglobin (Hb), and the cutoff point of the Hb level and the risk factors for transfusion. We implemented multidisciplinary blood-saving protocols.

RESULTS

The overall operative mortality and the success rate of OPCAB without transfusion were 2.9% (3/102) and 73.5% (75/102). The success rates in patients with Hb<11, 11 <Hb<14, and 14<Hb were 35.0%, 79.2%, and 89.7% (p=0.01), respectively. The risk factors for transfusion are age>70 years, diagnosis of acute myocardial infarction, preoperative Hb and creatinine levels, and operation time. The events precipitating the need for transfusion were low Hb level in 9 patients and hypotension or excessive bleeding in 18 patients.

CONCLUSION

The preoperative Hb level of >11 facilitates OPCAB without transfusion. These results suggest that transfusion-free OPCAB can be performed by modifying the risk factors and correctable causes of transfusion and improving various blood salvage methods.

Possible transfusion-related acute lung injury (TRALI) in cardiac surgery patients

Aim

To determine the incidence of possible transfusion-related acute lung injury (TRALI) and related risk factors in cardiac surgery patients.

Methods

A single-center prospective cohort study was conducted from January 2009 to March 2010 at the Zagreb University Hospital Center, Croatia. Patient-, transfusion-, and surgery-related data were collected. The study included 262 patients who were observed for respiratory worsening including measurements of arterial oxygen saturation (SaO₂), fraction of inspired oxygen (FiO₂), and partial pressure of arterial oxygen (PaO₂). Possible TRALI was defined according to the Toronto Consensus Conference definition broadened for 24-hour post-transfusion. This cohort was divided in two groups. TRALI group included 32 participants with diagnosis of TRALI and the control group included 220 patients with or without respiratory worsening, but with no signs of ALI.

Results

Possible TRALI was observed in 32 (12.2%) patients. Compared with the control group, possible TRALI patients had higher American Association of Anesthesiology scores, higher rate of respiratory comorbidity (43.8% vs 15.5%), and required more red blood cells (median 4, range [2.5-6] vs 2 [1-3]), plasma (5 [0-6] vs 0 [0-2]), and platelet units (0 [0-8] vs 0 [0-0]) (P < 0.001 all). Risk factors for possible TRALI were total number of transfused blood units (odds ratio [OR] 1.23; 95% confidence interval [CI] 1.10-1.37) and duration of cardiopulmonary bypass (OR 1.08; 95% CI 1.05-1.11). Post-transfusion PaO₂/FiO₂ ratio was significantly decreased in possible TRALI patients and significantly increased in transfused controls without acute lung injury.

Conclusion

We observed a higher rate of possible TRALI cases than in other studies on cardiac surgery patients. Serial monitoring of PaO₂/FiO₂ ratio and detection of its post-transfusion worsening aids in identification of possible TRALI cases.

Health care-associated infection after red blood cell transfusion: a systematic review and meta-analysis

IMPORTANCE

The association between red blood cell (RBC) transfusion strategies and health care-associated infection is not fully understood.

OBJECTIVE

To evaluate whether RBC transfusion thresholds are associated with the risk of infection and whether risk is independent of leukocyte reduction.

DATA SOURCES

MEDLINE, EMBASE, Web of Science Core Collection, Cochrane Central Register of Controlled Trials, Cochrane Database of Sytematic Reviews, ClinicalTrials.gov, International Clinical Trials Registry, and the International Standard Randomized Controlled Trial Number register were searched through January 22, 2014.

STUDY SELECTION

Randomized clinical trials with restrictive vs liberal RBC transfusion strategies.

DATA EXTRACTION AND SYNTHESIS

Twenty-one randomized trials with 8735 patients met eligibility criteria, of which 18 trials (n = 7593 patients) contained sufficient information for meta-analyses. DerSimonian and Laird random-effects models were used to report pooled risk ratios. Absolute risks of infection were calculated using the profile likelihood random-effects method.

MAIN OUTCOMES AND MEASURES

Incidence of health care-associated infection such as pneumonia, mediastinitis, wound infection, and sepsis.

RESULTS

The pooled risk of all serious infections was 11.8% (95% CI, 7.0%-16.7%) in the restrictive group and 16.9% (95% CI, 8.9%-25.4%) in the liberal group. The risk ratio (RR) for the association between transfusion strategies and serious infection was 0.82 (95% CI, 0.72-0.95) with little heterogeneity (I2 = 0%; τ2 <.0001). The number needed to treat (NNT) with restrictive strategies to prevent serious infection was 38 (95% CI, 24-122). The risk of infection remained reduced with a restrictive strategy, even with leukocyte reduction (RR, 0.80 [95% CI, 0.67-0.95]). For trials with a restrictive hemoglobin threshold of <7.0 g/dL, the RR was 0.82 (95% CI, 0.70-0.97) with NNT of 20 (95% CI, 12-133). With stratification by patient type, the RR was 0.70 (95% CI, 0.54-0.91) in patients undergoing orthopedic surgery and 0.51 (95% CI, 0.28-0.95) in patients presenting with sepsis. There were no significant differences in the incidence of infection by RBC threshold for patients with cardiac disease, the critically ill, those with acute upper gastrointestinal bleeding, or for infants with low birth weight.

CONCLUSIONS AND RELEVANCE

Among hospitalized patients, a restrictive RBC transfusion strategy was associated with a reduced risk of health care-associated infection compared with a liberal transfusion strategy. Implementing restrictive strategies may have the potential to lower the incidence of health care-associated infection.

Storage duration of red blood cell transfusion and Clostridium difficile infection: a within person comparison

OBJECTIVE

Randomized controlled trials demonstrated that red blood cell (RBC) transfusion elevates the risk of infection, and trials are underway to evaluate whether RBC storage affects outcomes. We previously reported that transfusion predicts Clostridium difficile infection (CDI) and, therefore, planned an investigation to examine this further using a more robust design.

DESIGN

Within-person case-crossover study. Hospitalizations in which CDI developed (n = 406) were compared to hospitalizations for the same individuals in which CDI did not occur (n = 949). Transfusion volume and storage duration were assessed prior to the onset of CDI.

SETTING

University of Michigan Health System.

PATIENTS

Participants were individuals with a diagnosis of CDI from July 2009 through June 2012.

MEASUREMENTS AND MAIN RESULTS

During the hospitalizations when CDI occurred, 34.7% of the patients received allogeneic RBC transfusions (mean volume, 688 ml) compared to 19.0% of patients in hospitalizations without CDI (mean volume, 180 ml). The odds of healthcare-associated CDI increased by 76% (95% CI 1.39-2.23) for every liter of RBCs transfused and was elevated in both nonsurgical (OR = 1.90) and surgical (OR = 1.86) hospitalizations. In patients who received RBC transfusions, the odds of developing CDI increased by 6% for every additional day of RBC stored and by 53% for every week of additional storage (P = 0.002).

CONCLUSIONS

Hospitalizations in which a patient received a greater volume of RBC transfusions were more likely to be associated with the development of CDI. RBC units stored for a longer duration were associated with the development of healthcare-associated CDI after adjustment for RBC volume.