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

Preoperative Anemia and Postoperative Outcomes in Cardiac Surgery: A Mediation Analysis Evaluating Intraoperative Transfusion Exposures

BACKGROUND

Preoperative anemia is associated with adverse outcomes in cardiac surgery, yet it remains unclear what proportion of this association is mediated through red blood cell (RBC) transfusions.

METHODS

This is a historical observational cohort study of adults undergoing coronary artery bypass grafting or valve surgery on cardiopulmonary bypass at an academic medical center between May 1, 2008, and May 1, 2018. A mediation analysis framework was used to evaluate the associations between preoperative anemia and postoperative outcomes, including a primary outcome of acute kidney injury (AKI). Intraoperative RBC transfusions were evaluated as mediators of preoperative anemia and outcome relationships. The estimated total effect, average direct effect of preoperative anemia, and percent of the total effect mediated through transfusions are presented with 95% confidence intervals and P -values.

RESULTS

A total of 4117 patients were included, including 1234 (30%) with preoperative anemia. Overall, 437 of 4117 (11%) patients went on to develop AKI, with a greater proportion of patients having preoperative anemia (219 of 1234 [18%] vs 218 of 2883 [8%]). In multivariable analyses, the presence of preoperative anemia was associated with increased postoperative AKI (6.4% [4.2%-8.7%] absolute difference in percent with AKI, P < .001), with incremental decreases in preoperative hemoglobin concentrations displaying greater AKI risk (eg, 11.9% [6.9%-17.5%] absolute increase in probability of AKI for preoperative hemoglobin of 9 g/dL compared to a reference of 14 g/dL, P < .001). The association between preoperative anemia and postoperative AKI was primarily due to direct effects of preoperative anemia (5.9% [3.6%-8.3%] absolute difference, P < .001) rather than mediated through intraoperative RBC transfusions (7.5% [-4.3% to 21.1%] of the total effect mediated by transfusions, P = .220). Preoperative anemia was also associated with longer hospital durations (1.07 [1.05-1.10] ratio of geometric mean length of stay, P < .001). Of this total effect, 38% (22%, 62%; P < .001) was estimated to be mediated through subsequent intraoperative RBC transfusion. Preoperative anemia was not associated with reoperation or vascular complications.

CONCLUSIONS

Preoperative anemia was associated with higher odds of AKI and longer hospitalizations in cardiac surgery. The attributable effects of anemia and transfusion on postoperative complications are likely to differ across outcomes. Future studies are necessary to further evaluate mechanisms of anemia-associated postoperative organ injury and treatment strategies.

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.

Chronic Kidney Disease After Partial Nephrectomy in Patients With Preoperative Inconspicuous Renal Function - Curiosity or Relevant Issue?

BACKGROUND

Chronic kidney disease (CKD) is a severe long-term complication after partial nephrectomy (PN). Clinical and scientific focus lies on patients with impaired renal function at the time of surgery. Little data is available on patients with normal preoperative renal function (NPRF).

PATIENTS AND METHODS

Patients who underwent PN with a preoperative estimated glomular filtration rate > 60 mL/min/1.73m² were retrospectively examined at 8 European urologic centers. The occurrence of new onset CKD ≥ stage III after surgery (sCKD) was defined as the primary endpoint. Group comparisons and risk correlations were determined. Based on this data, a risk stratification model for sCKD was developed.

RESULTS

Of the 1315 patients with NPRF included, 249 (18.9%) developed sCKD after a median follow-up of 44 months (range, 6-255 months). Pair analysis and univariable regression revealed age, arterial hypertension, American Society of Anesthesiologists score, tumor stage, surgical approach, intraoperative blood loss, perioperative blood transfusions and preoperative CKD stage as predictors for sCKD development. Multivariate analysis confirmed perioperative blood transfusion (hazard ratio [HR], 2.96; P ≤ .0001), age (≥ 55 years; HR, 2.60; P = .0002), tumor stage (> pT1; HR, 2.15; P = .025), and preoperative CKD stage (stage II vs. I; HR, 3.85; P ≤ .0001) as independent risk factors. A model that stratified patient risk for new onset CKD was highly significant (P < .0001).

CONCLUSION

Every fifth patient with NPRF developed sCKD following PN. Elderly patients with higher tumor stage and who require blood transfusion appear to be at increased risk. Based on our risk stratification, patients with ≥ 2 risk factors are candidates for an early, nephrologic follow-up.

Clinical effectiveness of 3 days preoperative treatment with recombinant human erythropoietin in total knee arthroplasty surgery: a clinical trial

AIMS

The purpose of study is to evaluate the effect and complication of preoperative short-term daily recombinant human erythropoietin (rhEPO) treatment for blood-saving in patients undergoing unilateral primary total knee arthroplasty (TKA).

METHODS

This three-arm randomized clinical trial compared three different rhEPO-based treatment protocols for unilateral primary TKA. Group A: application of daily doses of rhEPO combined with iron supplement starting 3 days before surgery; Group B: application of daily doses of rhEPO combined with iron supplement starting the day of surgery; Group C: iron supplement alone. Perioperative hemoglobin (Hb) level gaps, total perioperative blood loss, reticulocyte levels and treatment-related complications were studied.

RESULTS

A total of 102 patients were included (35, 35 and 32 patients in Groups A, B and C, respectively). Total blood loss (TBL) in Groups A, B and C was 490.84, 806.76 and 924.21 ml, respectively. Patients in Group A had a significant lower TBL than Groups B and C (A vs. B: P = 0.010; A vs. C: P < 0.001). There was no difference as for TBL between Groups B and C (P = 0.377). Group A patients had significant smaller Hb decline than Group C on the third and fifth postoperative day (P = 0.049, P = 0.037), as well as than Group B on the fifth postoperative day (P = 0.048). There was no difference as for Hb decline between Groups B and C. No difference was shown in levels of inflammatory biomarkers or blood-saving protocol-related complications among three groups.

CONCLUSIONS

Daily dose of rhEPO combined with iron supplement administered 3 days before TKA procedures could significantly decrease perioperative blood loss and improve postoperative Hb levels, without significantly elevating risks of complication, when compared with admission of rhEPO on the day of surgery and iron supplement alone. Preoperative daily rhEPO treatment could be a more effective blood-saving protocol in TKA procedures.

Minimizing Blood Loss in Spine Surgery

STUDY DESIGN

Broad narrative review.

OBJECTIVE

To review and summarize the current literature on guidelines, outcomes, techniques and indications surrounding multiple modalities of minimizing blood loss in spine surgery.

METHODS

A thorough review of peer-reviewed literature was performed on the guidelines, outcomes, techniques, and indications for multiple modalities of minimizing blood loss in spine surgery.

RESULTS

There is a large body of literature that provides a consensus on guidelines regarding the appropriate timing of discontinuation of anticoagulation, aspirin, nonsteroidal anti-inflammatory drugs (NSAIDs), and herbal supplements prior to surgery. Additionally, there is a more heterogenous discussion the utility of preoperative autologous blood donation facilitated by erythropoietin and iron supplementation for healthy patients slated for procedures with high anticipated blood loss and for whom allogeneic transfusion is likely. Intraoperative maneuvers available to minimize blood loss include positioning and maintaining normothermia. Tranexamic acid (TXA), bipolar sealer electrocautery, and topical hemostatic agents, and hypotensive anesthesia (mean arterial pressure (MAP) <65 mm Hg) should be strongly considered in cases with larger exposures and higher anticipated blood loss. There is strong level 1 evidence for the use of TXA in spine surgery as it reduces the overall blood loss and transfusion requirements.

CONCLUSION

As the volume and complexity of spinal procedures rise, intraoperative blood loss management has become a pivotal topic of research within the field. There are many tools for minimizing blood loss in patients undergoing spine surgery. The current literature supports combining techniques to use a cost- effective multimodal approach to minimize blood loss in the perioperative period.

Effect of postoperative haemoglobin variation on major cardiopulmonary complications in high cardiac risk patients undergoing anatomical lung resections

OBJECTIVES

Recent evidence shows that permissive anaemia strategies are safe in different surgical settings. However, effects of variations in haemoglobin (Hb) levels could have a negative impact in high-risk patients. We investigated the combined effect of postoperative Hb concentration and cardiac risk status on major cardiopulmonary complications after anatomical lung resections.

METHODS

We retrospectively analysed the records, collected in a prospective clinical database, of 154 consecutive patients undergoing anatomical lung resections at our institution (February 2017-February 2019). Hb levels were displayed as preoperative concentration, nadir Hb level before onset of complications and delta Hb (ΔHb). Cardiac risk was stratified according to the Thoracic Revised Cardiac Risk Index (ThRCRI). Univariable and multivariable logistic regression analyses were used to test the associations between patients, surgical variables and cardiopulmonary complications according to the European Society of Thoracic Surgeons definitions.

RESULTS

Cardiopulmonary complications occurred in 63 patients (17%). In the fully adjusted multivariable model, higher values of ΔHb were associated with increased risk of complications [odds ratio (OR) 1.07; P < 0.001], along with higher ThRCRI classes (classes A-B versus C-D: OR 0.09; P < 0.001). Interaction terms with transfusion were not statistically significant, indicating that the harmful effect of ΔHb was independent. According to receiver operating characteristic curve analysis, a ΔHb of 29 g/l was found to be the best cut-off value for predicting complications.

CONCLUSIONS

In our series, ΔHb, rather than nadir Hb, was associated with an increased risk of complications, particularly in patients with higher cardiac risk. Restrictive transfusion strategies should be carefully applied in patients undergoing lung resections and balanced according to individual clinical status.

Adverse Outcomes of Perioperative Red Blood Cell Transfusions in Coronary Artery Bypass Grafting in Hospital Universiti Sains Malaysia

BACKGROUND

Perioperative red blood cell (RBC) transfusion in coronary artery bypass grafting (CABG) has both benefits and harms. Our aim was to study the association between perioperative RBC transfusion and its adverse outcomes.

METHODS

This was a retrospective study of patients who underwent isolated CABG in Hospital Universiti Sains Malaysia, Kelantan, Malaysia, from 1 January 2013 until 31 December 2017. Data were collected from medical records, and comparisons were made between patients who received perioperative RBC transfusions and those who did not have adverse outcomes after CABG.

RESULTS

A total of 108 patients who underwent isolated CABG were included in our study, and 78 patients received perioperative RBC transfusions. Patients who received perioperative RBC transfusions compared to those who did not were significantly more likely to develop prolonged ventilatory support (21.8% versus 0%, P = 0.003), cardiac morbidity (14.1% versus 0%, P = 0.032), renal morbidity (28.2% versus 3.3%, P = 0.005) and serious infection (20.5% versus 3.3%, P = 0.037). With each unit of packed RBC transfusions, there was a significantly increased risk of prolonged ventilatory support (adjusted odds ratio [AOR] = 1.45; 95% confidence interval [CI] = 1.20-1.77; P < 0.001), cardiac morbidity (AOR =1.40; 95%CI = 1.01-1.79; P = 0.007), renal morbidity (AOR = 1.23; 95%CI = 1.03-1.45; P = 0.019) and serious infection (AOR = 1.31; 95%CI = 1.07-1.60; P = 0.009).

CONCLUSION

Perioperative RBC transfusion in isolated CABG patients is associated with increased risks of developing adverse events such as prolonged ventilatory support, cardiac morbidity, renal morbidity and serious infection.

Therapeutic targets for the anemia of predialysis chronic kidney disease: a meta-analysis of randomized, controlled trials

Anemia is one of the major complications in predialysis patients with chronic kidney disease (CKD). A clearer cognition of the prognostic impact of hemoglobin (Hb) or hematocrit (Hct) target on the outcomes of predialysis patients with CKD is significant. This article aims to establish the suitable hemoglobin target to provide clinical guidance. MEDLINE, EmBase, the Cochrane Library and other databases were searched with both MeSH terms and keywords to gather researches that assessed all-cause mortality, stroke, treatment of renal replacement, and transfusion. The meta-analysis was accomplished via Revman 5.3 version. Totally, 13 eligible studies involving 7606 patients were included. There was a significantly lower risk of transfusion (risk ratio (RR) 0.59, 95% CI 0.52 to 0.67; p<0.00001) in the higher hemoglobin group than in the lower one. However, no significant difference was found in all-cause mortality (RR 1.10, 95% CI 0.98 to 1.23; p=0.11), stroke (RR 1.32, 95% CI 0.82 to 2.10; p=0.25) and treatment of renal replacement including hemodialysis, peritoneal dialysis and renal transplant (RR 1.08, 95% CI 0.95 to 1.22; p= 0.23) between the higher hemoglobin group and the lower one. The results favor the higher hemoglobin target. To target the higher hemoglobin when treating predialysis patients with CKD may decrease the risk of transfusion without increasing the risk of death, stoke, and treatment of renal replacement.

Clinical Short-Term Outcome and Hemodynamic Comparison of Six Contemporary Bovine Aortic Valve Prostheses

BACKGROUND

Conventional stented valves (CV) remain gold standard for aortic valve disease. Bovine prostheses have been improved and rapid deployment valves (RDV) have arrived in the recent decade. We compare clinical and hemodynamic short-term outcome of six bovine valves.

METHODS

We retrospectively evaluated 829 consecutive patients (all-comers) receiving bovine aortic valve replacement (AVR). Four CV from different manufacturers (Mitroflow, Crown, Perimount, Trifecta) and two RDV (Perceval, Intuity) were compared in terms of pre-, intra-, and postprocedural data. A risk model for mortality was created.

RESULTS

All valves reduced gradients. From 23 mm, all CV showed acceptable gradients. Twenty-one millimeter Mitroflow/Perceval and 19 mm Crown showed above-average gradients. As baseline data differed, we performed propensity matching between aggregated isolated CV and RDV groups. Cardiopulmonary bypass (CPB), clamp, and surgery times were shorter with RDV (87.4 ± 34.0 min vs 111.0 ± 34.2, 54.3 ± 21.1 vs 74.9 ± 20.4, 155.2 ± 42.9 vs 178.0 ± 46.8, p < 0.001). New pacemaker rate (10.1 vs 1.3%, p = 0.016) and the tendency toward neurologic events (8.9 vs 2.5%, p = 0.086) were higher using RDV, induced mainly by the Perceval. Early mortality was equal (2.5 vs 1.3%, p = 0.560). Revision for bleeding, dialysis, blood products, length-of-stay, gradients, and regurgitation was also equal. Risk analysis showed that low valve size, low ejection fraction, endocarditis, administration of red cells, and prolonged CPB time were predictors of elevated mortality.

CONCLUSION

Isolated bovine AVR has low mortality. Valves ≥ 23 mm show comparable gradients while the valve model matters < 23 mm. RDV should be used with care. Procedure-related times are shorter than those of CV but pacemaker implantation and neurologic events are more frequent (Perceval). Early mortality is low and valve performance comparable to CV.

The effect of tranexamic acid to reduce blood loss and transfusion on off-pump coronary artery bypass surgery: A systematic review and cumulative meta-analysis

STUDY OBJECTIVE

To assess the safety and efficacy of tranexamic acid (TA) on off-pump coronary artery bypass (OPCAB) surgery.

DESIGN

Meta-analysis.

SETTING

Operating room, OPCAB surgery, all surgeries were elective measurements. Searching the following data sources respectively: PubMed/MEDLINE, the Cochrane Library, EMBASE and reference lists of identified articles, we performed a meta-analysis of postoperative 24h blood loss, postoperative allogeneic transfusion, re-operation for massive bleeding, postoperative mortality, and postoperative thrombotic complications.

MAIN RESULTS

Using electronic databases, we selected 15 randomized control trials (RCTs), carried out between 2003 and 2016, with a total of 1250 patients for our review. TA significantly reduced the postoperative 24h blood loss (mean difference -213.32ml, 95% confidence intervals, -247.20ml to -179.43ml; P<0.0001). And, TA also significantly reduced the risk of packed red blood cell (PRBCs) transfusion (risk ratio 0.62; 95% confidence intervals 0.51 to 0.76; P<0.0001) and fresh frozen plasma (FFP) transfusion (0.65; 0.52 to 0.81; P<0.001). There were no statistical significance on platelet transfusion (risk difference -0.00, 95% confidence interval -0.02 to 0.02; P=0.73) and re-operation (0.00, -0.02 to 0.02; P=1.00). No association was found between TA and morbility (risk difference -0.00, 95% confidence interval -0.02 to 0.02; P=0.99) and thrombotic complications (-0.01, -0.01 to 0.02; P=0.70).

CONCLUSIONS

TA reduced the probability of receiving a PRBCs and FFP transfusion during OPCAB surgery. And no association with postoperative death and thrombotic events was found. However, further trials with an appropriate sample size are required to confirm TA safety in OPCAB surgery.

Hemoglobin targets for the anemia in patients with dialysis-dependent chronic kidney disease: a meta-analysis of randomized, controlled trials

BACKGROUND

Anemia is extremely common among dialysis patients and underlies some of the symptoms associated with reduced kidney function, including fatigue, depression, reduced exercise tolerance, and dyspnea.

OBJECTIVES

A clearer cognition of the prognosistic impact of hemoglobin (Hb) or hematocrit (Hct) target for the outcomes of dialysis patients is urgent. This article aims to establish the suitable hemoglobin in order to provide clinical guidance.

METHODS

MEDLINE, EmBase, the Cochrane Library and other databases were searched with both MeSH terms and keywords to gather randomized controlled trials that assessed all-cause mortality, cardiovascular events, fistula thrombosis, infectious diseases and transfusion among dialysis-dependent patients using erythropoiesis-stimulating agents. The meta-analysis was accomplished via Revman 5.3 version.

FINDINGS

Totally, nine eligible studies were included, with study subjects involving 3228 patients. There was a significantly higher risk of fistula thrombosis without heterogeneity (RR 1.34, 95% CI 1.15-1.55; p < 0.05) in the higher Hb target group than in the lower Hb target group in the fixed effects model. However, no significant difference was found in all-cause mortality in the fixed effects model (RR 1.09, 95% CI 0.93-1.27; p = 0.30), cardiovascular events (RR 0.77, 95% CI 0.31-1.92; p = 0.58), infectious diseases (RR 0.69, 95% CI 0.24-1.96; p = 0.49) and transfusion (RR 0.92, 95% CI 0.42-1.99; p = 0.82) in the random effects model between the higher Hb target group and the lower Hb target group.

DISCUSSION

The results favor lower Hb target. To target lower Hb target when treating dialysis patients with anemia may decrease the risk of fistula thrombosis without increasing the risk of death, cardiovascular events, infectious diseases and transfusion.

A multicentre randomised controlled trial of Transfusion Indication Threshold Reduction on transfusion rates, morbidity and health-care resource use following cardiac surgery (TITRe2)

BACKGROUND

Uncertainty about optimal red blood cell transfusion thresholds in cardiac surgery is reflected in widely varying transfusion rates between surgeons and cardiac centres.

OBJECTIVE

To test the hypothesis that a restrictive compared with a liberal threshold for red blood cell transfusion after cardiac surgery reduces post-operative morbidity and health-care costs.

DESIGN

Multicentre, parallel randomised controlled trial and within-trial cost-utility analysis from a UK NHS and Personal Social Services perspective. We could not blind health-care staff but tried to blind participants. Random allocations were generated by computer and minimised by centre and operation.

SETTING

Seventeen specialist cardiac surgery centres in UK NHS hospitals.

PARTICIPANTS

Patients aged > 16 years undergoing non-emergency cardiac surgery with post-operative haemoglobin < 9 g/dl. Exclusion criteria were: unwilling to have transfusion owing to beliefs; platelet, red blood cell or clotting disorder; ongoing or recurrent sepsis; and critical limb ischaemia.

INTERVENTIONS

Participants in the liberal group were eligible for transfusion immediately after randomisation (post-operative haemoglobin < 9 g/dl); participants in the restrictive group were eligible for transfusion if their post-operative haemoglobin fell to < 7.5 g/dl during the index hospital stay.

MAIN OUTCOME MEASURES

The primary outcome was a composite outcome of any serious infectious (sepsis or wound infection) or ischaemic event (permanent stroke, myocardial infarction, gut infarction or acute kidney injury) during the 3 months after randomisation. Events were verified or adjudicated by blinded personnel. Secondary outcomes included blood products transfused; infectious events; ischaemic events; quality of life (European Quality of Life-5 Dimensions); duration of intensive care or high-dependency unit stay; duration of hospital stay; significant pulmonary morbidity; all-cause mortality; resource use, costs and cost-effectiveness.

RESULTS

We randomised 2007 participants between 15 July 2009 and 18 February 2013; four withdrew, leaving 1000 and 1003 in the restrictive and liberal groups, respectively. Transfusion rates after randomisation were 53.4% (534/1000) and 92.2% (925/1003). The primary outcome occurred in 35.1% (331/944) and 33.0% (317/962) of participants in the restrictive and liberal groups [odds ratio (OR) 1.11, 95% confidence interval (CI) 0.91 to 1.34; p = 0.30], respectively. There were no subgroup effects for the primary outcome, although some sensitivity analyses substantially altered the estimated OR. There were no differences for secondary clinical outcomes except for mortality, with more deaths in the restrictive group (4.2%, 42/1000 vs. 2.6%, 26/1003; hazard ratio 1.64, 95% CI 1.00 to 2.67; p = 0.045). Serious post-operative complications excluding primary outcome events occurred in 35.7% (354/991) and 34.2% (339/991) of participants in the restrictive and liberal groups, respectively. The total cost per participant from surgery to 3 months postoperatively differed little by group, just £182 less (standard error £488) in the restrictive group, largely owing to the difference in red blood cells cost. In the base-case cost-effectiveness results, the point estimate suggested that the restrictive threshold was cost-effective; however, this result was very uncertain partly owing to the negligible difference in quality-adjusted life-years gained.

CONCLUSIONS

A restrictive transfusion threshold is not superior to a liberal threshold after cardiac surgery. This finding supports restrictive transfusion due to reduced consumption and costs of red blood cells. However, secondary findings create uncertainty about recommending restrictive transfusion and prompt a new hypothesis that liberal transfusion may be superior after cardiac surgery. Reanalyses of existing trial datasets, excluding all participants who did not breach the liberal threshold, followed by a meta-analysis of the reanalysed results are the most obvious research steps to address the new hypothesis about the possible harm of red blood cell transfusion.

TRIAL REGISTRATION

Current Controlled Trials ISRCTN70923932.

FUNDING

This project was funded by the National Institute for Health Research (NIHR) Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 20, No. 60. See the NIHR Journals Library website for further project information.

Risk of Acute Kidney Injury in Patients Randomized to a Restrictive Versus Liberal Approach to Red Blood Cell Transfusion in Cardiac Surgery: A Substudy Protocol of the Transfusion Requirements in Cardiac Surgery III Noninferiority Trial

Background:

When safe to do so, avoiding blood transfusions in cardiac surgery can avoid the risk of transfusion-related infections and other complications while protecting a scarce resource and reducing costs. This protocol describes a kidney substudy of the Transfusion Requirements in Cardiac Surgery III (TRICS-III) trial, a multinational noninferiority randomized controlled trial to determine whether the risk of major clinical outcomes in patients undergoing planned cardiac surgery with cardiopulmonary bypass is no greater with a restrictive versus liberal approach to red blood cell transfusion.

Objective:

The objective of this substudy is to determine whether the risk of acute kidney injury is no greater with a restrictive versus liberal approach to red blood cell transfusion, and whether this holds true in patients with and without preexisting chronic kidney disease.

Design and Setting:

Multinational noninferiority randomized controlled trial conducted in 73 centers in 19 countries (2014-2017).

Patients:

Patients (~4800) undergoing planned cardiac surgery with cardiopulmonary bypass.

Measurements:

The primary outcome of this substudy is perioperative acute kidney injury, defined as an acute rise in serum creatinine from the preoperative value (obtained in the 30-day period before surgery), where an acute rise is defined as ≥26.5 μmol/L in the first 48 hours after surgery or ≥50% in the first 7 days after surgery.

Methods:

We will report the absolute risk difference in acute kidney injury and the 95% confidence interval. We will repeat the primary analysis using alternative definitions of acute kidney injury, including staging definitions, and will examine effect modification by preexisting chronic kidney disease (defined as a preoperative estimated glomerular filtration rate [eGFR] <60 mL/min/1.73 m²).

Limitations:

It is not possible to blind patients or providers to the intervention; however, objective measures will be used to assess outcomes, and outcome assessors will be blinded to the intervention assignment.

Results:

Substudy results will be reported by the year 2018.

Conclusions:

This substudy will provide generalizable estimates of the risk of acute kidney injury of a restrictive versus liberal approach to red blood cell transfusion in the presence of anemia during cardiac surgery done with cardiopulmonary bypass.

Trial Registration:

www.clinicaltrials.gov; clinical trial registration number NCT 02042898.

Precatheterization Use of P2Y12 Inhibitors in Non-ST-Elevation Myocardial Infarction Patients Undergoing Early Cardiac Catheterization and In-Hospital Coronary Artery Bypass Grafting: Insights From the National Cardiovascular Data Registry®

Background

Current guidelines recommend early P2Y₁₂ inhibitor administration in non‐ST‐elevation myocardial infarction, but it is unclear if precatheterization use is associated with longer delays to coronary artery bypass grafting (CABG) or higher risk of post‐CABG bleeding and transfusion. This study examines the patterns and outcomes of precatheterization P2Y₁₂ inhibitor use in non‐ST‐elevation myocardial infarction patients who undergo CABG.

Methods and Results

Retrospective analysis was done of 20 304 non‐ST‐elevation myocardial infarction patients in the ACTION (Acute Coronary Treatment and Intervention Outcomes Network) Registry (2009–2014) who underwent catheterization within 24 hours of admission and CABG during the index hospitalization. Using inverse probability‐weighted propensity adjustment, we compared time from catheterization to CABG, post‐CABG bleeding, and transfusion rates between patients who did and did not receive precatheterization P2Y₁₂ inhibitors. Among study patients, 32.9% received a precatheterization P2Y₁₂ inhibitor (of these, 2.2% were given ticagrelor and 3.7% prasugrel). Time from catheterization to CABG was longer among patients who received precatheterization P2Y₁₂ inhibitor (median 69.9 hours [25th, 75th percentiles 28.2, 115.8] versus 43.5 hours [21.0, 71.8], P<0.0001), longer for patients treated with prasugrel (median 114.4 hours [66.5, 155.5]) or ticagrelor (90.4 hours [48.7, 124.5]) compared with clopidogrel (69.3 [27.5, 114.6], P<0.0001). Precatheterization P2Y₁₂ inhibitor use was associated with a higher risk of post‐CABG major bleeding (75.7% versus 73.4%, adjusted odds ratio 1.33, 95% confidence interval 1.22‐1.45, P<0.0001) and transfusion (47.6% versus 35.7%, adjusted odds ratio 1.51, 95% confidence interval 1.41‐1.62, P<0001); these relationships did not differ among patients treated with clopidogrel, prasugrel, or ticagrelor.

Conclusions

Precatheterization P2Y₁₂ inhibitor use occurs commonly among non‐ST‐elevation myocardial infarction patients who undergo early catheterization and in‐hospital CABG. Despite longer delays to surgery, the majority of pretreated patients proceed to CABG <3 days postcatheterization. Precatheterization P2Y₁₂ inhibitor use is associated with higher risks of postoperative bleeding and transfusion.

Point-of-care washing of allogeneic red blood cells for the prevention of transfusion-related respiratory complications (WAR-PRC): a protocol for a multicenter randomised clinical trial in patients undergoing cardiac surgery

INTRODUCTION

The transfusion-related respiratory complications, transfusion-related acute lung injury (TRALI) and transfusion-associated circulatory overload (TACO), are leading causes of transfusion-related morbidity and mortality. At present, there are no effective preventive strategies with red blood cell (RBC) transfusion. Although mechanisms remain incompletely defined, soluble biological response modifiers (BRMs) within the RBC storage solution may play an important role. Point-of-care (POC) washing of allogeneic RBCs may remove these BRMs, thereby mitigating their impact on post-transfusion respiratory complications.

METHODS AND ANALYSIS

This is a multicenter randomised clinical trial of standard allogeneic versus washed allogeneic RBC transfusion for adult patients undergoing cardiac surgery testing the hypothesis that POC RBC washing is feasible, safe, and efficacious and will reduce recipient immune and physiologic responses associated with transfusion-related respiratory complications. Relevant clinical outcomes will also be assessed. This investigation will enrol 170 patients at two hospitals in the USA. Simon's two-stage design will be used to assess the feasibility of POC RBC washing. The primary safety outcomes will be assessed using Wilcoxon Rank-Sum tests for continuous variables and Pearson chi-square test for categorical variables. Standard mixed modelling practices will be employed to test for changes in biomarkers of lung injury following transfusion. Linear regression will assess relationships between randomised group and post-transfusion physiologic measures.

ETHICS AND DISSEMINATION

Safety oversight will be conducted under the direction of an independent Data and Safety Monitoring Board (DSMB). Approval of the protocol was obtained by the DSMB as well as the institutional review boards at each institution prior to enrolling the first study participant. This study aims to provide important information regarding the feasibility of POC washing of allogeneic RBCs and its potential impact on ameliorating post-transfusion respiratory complications. Additionally, it will inform the feasibility and scientific merit of pursuing a more definitive phase II/III clinical trial.

REGISTRATION

ClinicalTrials.gov registration number is NCT02094118 (Pre-results).

Measurement of total hemoglobin reduces red cell transfusion in hospitalized patients undergoing cardiac surgery: a retrospective database analysis

Introduction:

Historically, perioperative hemoglobin monitoring has relied on calculated saturation, using blood gas devices that measure plasma hematocrit (Hct). Co-oximetry, which measures total hemoglobin (tHb), yields a more comprehensive assessment of hemodilution. The purpose of this study was to examine the association of tHb measurement by co-oximetry and Hct, using conductivity with red blood cell (RBC) transfusion, length of stay (LOS) and inpatient costs in patients having major cardiac surgery.

Methods:

A retrospective study was conducted on patients who underwent coronary artery bypass graft (CABG) and/or valve replacement (VR) procedures from January 2014 to June 2016, using MedAssets discharge data. The patient population was sub-divided by the measurement modality (tHb and Hct), using detailed billing records and Current Procedural Terminology coding. Cost was calculated using hospital-specific cost-to-charge ratios. Multivariable logistic regression was performed to identify significant drivers of RBC transfusion and resource utilization.

Results:

The study population included 18,169 cardiovascular surgery patients. Hct-monitored patients accounted for 66% of the population and were more likely to have dual CABG and VR procedures (10.4% vs 8.9%, p=0.0069). After controlling for patient and hospital characteristics, as well as patient comorbidities, Hct-monitored patients had significantly higher RBC transfusion risk (OR=1.26, CI 1.15-1.38, p<0.0001), longer LOS (IRR=1.08, p<0.0001) and higher costs (IRR=1.15, p<0.0001) than tHb-monitored patients. RBC transfusions were a significant driver of LOS (IRR=1.25, p<0.0001) and cost (IRR=1.22, p<0.0001).

Conclusions:

tHb monitoring during cardiovascular surgery could offer a significant reduction in RBC transfusion, length of stay and hospital cost compared to Hct monitoring.

Association between CK-MB Area Under the Curve and Tranexamic Acid Utilization in Patients Undergoing Coronary Artery Bypass Surgery

Myonecrosis after coronary artery bypass graft (CABG) surgery is associated with excess mortality. Tranexamic acid (TA), an anti-fibrinolytic agent, has been shown to reduce peri-operative blood loss without increasing the risk of myocardial infarction (MI); however, no large study has examined the association between TA treatment and post-CABG myonecrosis. In the MC-1 to Eliminate Necrosis and Damage in Coronary Artery Bypass Graft Surgery II trial, inverse probability weighting of the propensity to receive TA was used to test for differences among the 656 patients receiving and 770 patients not receiving TA. The primary outcome was creatine kinase MB (CK-MB) area under the curve (AUC) through 24 h. The secondary outcome was 30-day cardiovascular death or MI. Patients who received TA were more frequently female, had a previous MI, heart failure, low molecular weight heparin therapy, on-pump CABG, valvular surgery, and saphenous vein or radial grafts. The median 24-h CK-MB AUC was higher in TA-treated patients [301.9 (IQR 196.7-495.6) vs 253.5 (153.4-432.5) ng h/mL, p < 0.001]. No differences in the 30-day incidence of cardiovascular death or MI were observed (8.7 vs 8.3%, adjusted OR 0.99; 95% CI 0.67-1.45, p = 0.948). In patients undergoing CABG, TA use was associated with a higher risk of myonecrosis; however, no differences were observed in death or MI. Future larger studies should be directed at examining the pathophysiology of TA myonecrosis, and its association with subsequent clinical outcomes.

Clinical Decision Support for Pediatric Blood Product Prescriptions

Since the beginning of the 20th century, blood products have been used to effectively treat life-threatening conditions. Over time, we have come to appreciate the many benefits along with significant risks inherent to blood product transfusions. As such, recommendations for the safe and effective use of blood products have evolved over time. Current evidence supports the use of restrictive transfusion strategies that can avoid the risks of unnecessary transfusions. In spite of good evidence, there is a considerable amount of variability in transfusion practices across providers. Clinical decision support (CDS) is an effective tool capable of increasing adherence to evidence-based practices. CDS has been used successfully to improve adherence to transfusion guidelines. Pediatric literature demonstrates strong evidence for the use of CDS to improve appropriateness of red blood cell and plasma transfusion utilization. Further studies in more diverse settings with more standardized reporting are needed to provide more clarity around the effectiveness of CDS in blood product prescriptions.

Purified and Recombinant Hemopexin: Protease Activity and Effect on Neutrophil Chemotaxis

Infusion of the heme-binding protein hemopexin has been proposed as a novel approach to decrease heme-induced inflammation in settings of red blood cell breakdown, but questions have been raised as to possible side effects related to protease activity and inhibition of chemotaxis. We evaluated protease activity and effects on chemotaxis of purified plasma hemopexin obtained from multiple sources as well as a novel recombinant fusion protein Fc-hemopexin. Amidolytic assay was performed to measure the protease activity of several plasma-derived hemopexin and recombinant Fc-hemopexin. Hemopexin was added to the human monocyte culture in the presence of lipopolysaccharides (LPS), and also injected into mice intravenously (i.v.) 30 min before inducing neutrophil migration via intraperitoneal (i.p.) injection of thioglycolate. Control groups received the same amount of albumin. Protease activity varied widely between hemopexins. Recombinant Fc-hemopexin bound heme, inhibited the synergy of heme with LPS on tumor necrosis factor (TNF) production from monocytes, and had minor but detectable protease activity. There was no effect of any hemopexin preparation on chemotaxis, and purified hemopexin did not alter the migration of neutrophils into the peritoneal cavity of mice. Heme and LPS synergistically induced the release of LTB4 from human monocytes, and hemopexin blocked this release, as well as chemotaxis of neutrophils in response to activated monocyte supernatants. These results suggest that hemopexin does not directly affect chemotaxis through protease activity, but may decrease heme-driven chemotaxis and secondary inflammation by attenuating the induction of chemoattractants from monocytes. This property could be beneficial in some settings to control potentially damaging inflammation induced by heme.

Risk factors and outcomes of blood transfusions in adrenalectomy

BACKGROUND

Blood transfusion has been shown to be associated with adverse long-term and short-term outcomes. We sought to evaluate the preoperative risk factors associated with blood transfusion and its effects on postoperative outcomes after adrenalectomy.

METHODS

We performed a retrospective analysis of 4735 adrenalectomies (3664 laparoscopic and 1071 open) from 2005-2012 using the National Surgical Quality Improvement Program database. Data on preoperative risk factors and postoperative morbidity and mortality were evaluated.

RESULTS

Median age and body mass index were 54 y and 29.3 kg/m(2), respectively. Most patients were female (60.0%). Of the total, 60.6% patients had American Society of Anesthesiologists score ≥3. On multivariate analysis, increasing age (odds ratio [OR] = 1.02, P < 0.001), open adrenalectomy (OR = 14.0, P < 0.001), preoperative hematocrit <38% (OR = 2.96, P < 0.001), and operative time >150 min (OR: 3.69, P < 0.001) were associated with an increased need for intraoperative blood transfusions. The need for intraoperative blood transfusions was an independent predictor of postoperative complications including mortality (OR = 12.7, P < 0.001), overall morbidity (OR = 3.2, P < 0.001), serious morbidity (OR = 3.8, P < 0.001), wound complication (OR = 2.1, P = 0.006), cardiopulmonary complication (OR = 3.6, P < 0.001), septic complication (OR = 2.5, P = 0.007), reoperation (OR = 3.6, P < 0.001), and prolonged length of stay (OR = 4.3, P < 0.001). There was an independent and incremental increase (10%-20%) in the risk of morbidity and mortality with each unit of blood transfused (P < 0.01).

CONCLUSIONS

Age, open surgery, preoperative anemia, American Society of Anesthesiologists score, and prolonged operative time are associated with an increased need for blood transfusions in laparoscopic and open adrenalectomy. Intraoperative transfusion was independently and incrementally associated with significant morbidity and mortality after laparoscopic and open adrenalectomy.

Liberal or restrictive transfusion after cardiac surgery

BACKGROUND

Whether a restrictive threshold for hemoglobin level in red-cell transfusions, as compared with a liberal threshold, reduces postoperative morbidity and health care costs after cardiac surgery is uncertain.

METHODS

We conducted a multicenter, parallel-group trial in which patients older than 16 years of age who were undergoing nonemergency cardiac surgery were recruited from 17 centers in the United Kingdom. Patients with a postoperative hemoglobin level of less than 9 g per deciliter were randomly assigned to a restrictive transfusion threshold (hemoglobin level <7.5 g per deciliter) or a liberal transfusion threshold (hemoglobin level <9 g per deciliter). The primary outcome was a serious infection (sepsis or wound infection) or an ischemic event (permanent stroke [confirmation on brain imaging and deficit in motor, sensory, or coordination functions], myocardial infarction, infarction of the gut, or acute kidney injury) within 3 months after randomization. Health care costs, excluding the index surgery, were estimated from the day of surgery to 3 months after surgery.

RESULTS

A total of 2007 patients underwent randomization; 4 participants withdrew, leaving 1000 in the restrictive-threshold group and 1003 in the liberal-threshold group. Transfusion rates after randomization were 53.4% and 92.2% in the two groups, respectively. The primary outcome occurred in 35.1% of the patients in the restrictive-threshold group and 33.0% of the patients in the liberal-threshold group (odds ratio, 1.11; 95% confidence interval [CI], 0.91 to 1.34; P=0.30); there was no indication of heterogeneity according to subgroup. There were more deaths in the restrictive-threshold group than in the liberal-threshold group (4.2% vs. 2.6%; hazard ratio, 1.64; 95% CI, 1.00 to 2.67; P=0.045). Serious postoperative complications, excluding primary-outcome events, occurred in 35.7% of participants in the restrictive-threshold group and 34.2% of participants in the liberal-threshold group. Total costs did not differ significantly between the groups.

CONCLUSIONS

A restrictive transfusion threshold after cardiac surgery was not superior to a liberal threshold with respect to morbidity or health care costs. (Funded by the National Institute for Health Research Health Technology Assessment program; Current Controlled Trials number, ISRCTN70923932.).

Efficacy of education followed by computerized provider order entry with clinician decision support to reduce red blood cell utilization

BACKGROUND

Two necessary components of a patient blood management program are education regarding evidence-based transfusion guidelines and computerized provider order entry (CPOE) with clinician decision support (CDS). This study examines changes in red blood cell (RBC) utilization associated with each of these two interventions.

STUDY DESIGN AND METHODS

We reviewed 5 years of blood utilization data (2009-2013) for 70,118 surgical patients from 10 different specialty services at a tertiary care academic medical center. Three distinct periods were compared: 1) before blood management, 2) education alone, and 3) education plus CPOE. Changes in RBC unit utilization were assessed over the three periods stratified by surgical service. Cost savings were estimated based on RBC acquisition costs.

RESULTS

For all surgical services combined, RBC utilization decreased by 16.4% with education alone (p = 0.001) and then changed very little (2.5% increase) after subsequent addition of CPOE (p = 0.64). When we compared the period of education plus CPOE to the pre-blood management period, the overall decrease was 14.3% (p = 0.008; 2102 fewer RBC units/year, or a cost avoidance of $462,440/year). Services with the highest massive transfusion rates (≥10 RBC units) exhibited the least reduction in RBC utilization.

CONCLUSIONS

Adding CPOE with CDS after a successful education effort to promote evidence-based transfusion practice did not further reduce RBC utilization. These findings suggest that education is an important and effective component of a patient blood management program and that CPOE algorithms may serve to maintain compliance with evidence-based transfusion guidelines.

Benefit from using recycling red blood cells in cardiovascular surgery

Objective

To show if blood salvage is indicated in all patients submitted to cardiovascular surgery with cardiopulmonary bypass.

Methods

We studied 77 consecutive patients submitted to cardiac surgery with use of blood salvage and cardiopulmonary bypass from November 2010 to June 2012. The sample was divided in three groups, depending on the time of cardiopulmonary bypass. In group A, the time of cardiopulmonary bypass was smaller than 45, in group B from 45 to 90 and in group C greater than 90 minutes. We analyzed the volume of red cells recovered and infused, the pre, intra and post-operative hemoglobin, the number of packed red cells units which were transfused and hematocrit and hemoglobin blood infused.

Results

The average group age was 60.44±12.09 years old, of whom 71.43% were males. The group A was formed by 5.19% of the patients, B by 81.82% and C by 12.99%. The volume of erythrocytes recovered and infused was respectively 1,360.50±511.37 ml and 339.75±87.71 ml in group A, 1,436.63±516.06 ml and 518.83±183.0 ml in B and 2,137.00±925.04 ml and 526.20±227.15 ml in C. About packed red cells transfusions, in group A 1,00±2,00 packed red cells were transfused, in B 1.27±1.85 packed red cells and in C 2.56±2.01 packed red cells. The infused blood had a hematocrit of 50.97±12.06% and hemoglobin of 19.57±8.35 g/dl.

Conclusion

That blood salvage can be used in patients submitted to cardiovascular surgery with cardiopulmonary bypass. However, it is only cost-effective in surgeries in which the time of cardiopulmonary bypass is greater than 45 minutes.

Radiofrequency bipolar hemostatic sealer reduces blood loss, transfusion requirements, and cost for patients undergoing multilevel spinal fusion surgery: a case control study

Background

A relatively new method of electrocautery, the radiofrequency bipolar hemostatic sealer (RBHS), uses saline-cooled delivery of energy, which seals blood vessels rather than burning them. We assessed the benefits of RBHS as a blood conservation strategy in adult patients undergoing multilevel spinal fusion surgery.

Methods

In a retrospective cohort study, we compared blood utilization in 36 patients undergoing multilevel spinal fusion surgery with RBHS (Aquamantys®, Medtronic, Minneapolis, MN, USA) to that of a historical control group (n = 38) matched for variables related to blood loss. Transfusion-related costs were calculated by two methods.

Results

Patient characteristics in the two groups were similar. Intraoperatively, blood loss was 55% less in the RBHS group than in the control group (810 ± 530 vs. 1,800 ± 1,600 mL; p = 0.002), and over the entire hospital stay, red cell utilization was 51% less (2.4 ± 3.4 vs. 4.9 ± 4.5 units/patient; p = 0.01) and plasma use was 56% less (1.1 ± 2.4 vs. 2.5 ± 3.4 units/patient; p = 0.03) in the RBHS group. Platelet use was 0.1 ± 0.5 and 0.3 ± 0.6 units/patient in the RBHS and control groups, respectively (p = 0.07). The perioperative decrease in hemoglobin was less in the RBHS group than in the control group (−2.0 ± 2.2 vs. –3.2 ± 2.1 g/dL; p = 0.04), and hemoglobin at discharge was higher in the RBHS group (10.5 ± 1.4 vs. 9.7 ± 0.9 g/dL; p = 0.01). The estimated transfusion-related cost savings were $745/case by acquisition cost and approximately 3- to 5-fold this amount by activity-based cost.

Conclusions

The use of RBHS in patients undergoing multilevel spine fusion surgery can conserve blood, promote higher hemoglobin levels, and reduce transfusion-related costs.

Marked changes in platelet count and function following pediatric congenital heart surgery

BACKGROUND

Reduced hemostatic capacity is common following congenital heart surgery using cardiopulmonary bypass (CPB). The etiology is multifactorial with dilutional coagulopathy, as well as platelet adhesion and activation in the CPB circuit and oxygenator. The purpose of the present study was to evaluate platelet count and function in children following CPB.

METHODS

In a prospective, observational study comprising 40 children, platelet count and function (Multiplate Analyzer(®)) were measured before surgery, immediately after bypass, and on the first postoperative day. Furthermore, conventional coagulation analysis and thromboelastometry (ROTEM(®)) were carried out.

RESULTS

A significant decrease in platelet count was observed immediately after coming of bypass (P < 0.001) and persisted to the first postoperative day (P = 0.002). Platelet function was reduced immediately after bypass after induction with ADP (P < 0.001) or TRAP (P = 0.03). The duration of CPB correlated significantly with the decrease in platelet count (r = -0.62, P = 0.0001) and reduction in platelet function (r = -0.42-0.63; P < 0.01). Moderate to deep hypothermia during CPB was associated with a decreased platelet function (P = 0.01-0.12), whereas cyanosis or previous heart surgery caused no further changes in platelet function following CPB.

CONCLUSION

Both platelet count and platelet function were significantly reduced after CPB in children undertaken correctional heart surgery. Duration of CPB and hypothermia was associated with significant changes in platelet function.

Safe application of a restrictive transfusion protocol in moderate-risk patients undergoing cardiac operations

BACKGROUND

Perioperative red blood cell transfusion is associated with adverse outcomes after cardiac operations. Although restrictive transfusion protocols have been developed, their safety and efficacy are not well demonstrated, and considerable variation in transfusion practice persists. We report our experience with a restrictive transfusion protocol.

METHODS

We analyzed the outcomes in 409 patients undergoing cardiac operations enrolled in a trial conducted at 30 centers worldwide. Blood products were administered on the basis of a transfusion algorithm applied across all centers, with a restrictive transfusion trigger of hemoglobin less than or equal to 6 g/dL. Transfusion was acceptable but not mandatory for hemoglobin 6 to 8 g/dL. For hemoglobin 8 to 10 g/dL, transfusion was acceptable only with evidence for end-organ ischemia.

RESULTS

The patient population was moderately complex, with 20.5% having combined procedures and 29.6% having nonelective operations. The mean EuroSCORE for the population was 4.3, which predicted a substantial incidence of morbidity and mortality. Actual outcomes were excellent, with observed mortality of 0.49% and rates of cerebrovascular accident, myocardial infarction, and acute renal failure 1.2%, 6.1%, and 0.98%, respectively. The frequency of red blood cell transfusion was 33.7%, which varied significantly by center. Most transfusions (71.9%) were administered for hemoglobin 6 to 8 g/dL; 21.4% were administered for hemoglobin 8 to 10 g/dL with evidence for end-organ ischemia; 65.0% of patients avoided allogeneic transfusion altogether.

CONCLUSIONS

A restrictive transfusion protocol can be safely applied in the care of moderate-risk patients undergoing cardiac operations. This strategy has significant potential to reduce transfusion and resource utilization in these patients, standardize transfusion practices across institutions, and increase the safety of cardiac operations.

A study on knowledge, attitude and practice regarding voluntary blood donation among medical students in Puducherry, India

Knowledge, attitude and practice studies have been used to understand the various factors that influence blood donation which is the basis for donor mobilization and retention strategies. Role of youngsters in voluntary blood donation is crucial to meet the demand of safe blood. The present study was aimed to assess the level of knowledge, attitude and practice regarding voluntary blood donation among the health care students. A validated and pre-tested questionnaire on knowledge, attitude and practice on blood donation were assessed among 371 medical students from Sri Lakshmi Narayana Institute of Medical Sciences and Research Institute, Puducherry, India. Result showed that knowledge on blood donation among respondents was 44.8% (1st year 36.7%, 2nd year 42.8% and 3rd year 54.9%). About 62.6% of non-donors (1st year 51%, 2nd year 61% and 3rd year 77%) showed positive attitude by expressing their willingness to donate blood while 22.8%.of the non-donors had negative attitude (1st year 33%, 2nd year 23% and 3rd year 13%). In practice 13.2% of students had donated blood (1st year 10%, 2nd year 13% and 3rd year 24%), in which 2.7% of male students alone donating blood on regular basis. Over all 3rd year student showed significantly higher knowledge compared with 1st years, in attitude and practice section 3rd year student's showed significantly higher positive attitude and practice than that of 1st and 2nd years. The present study reveals that there is a positive association among knowledge, attitude and practice on blood donation, which suggest that positive attitude and practice can be improved by inculcating knowledge on blood donation among college students to recruit and donate blood regularly, which will help to achieve 100% of blood donation on voluntary basis.

Development of a risk-adjusted blood utilization metric

BACKGROUND

Blood utilization has become an important outcome measure for surgical patients because of the recognized risks and costs associated with transfusion. However, comparisons of blood utilization between providers or institutions are difficult, because there is no standard method for risk adjustment when assessing surgical blood requirements. We examined whether accepted diagnosis-related group (DRG) case mix indexes can be used for this purpose.

STUDY DESIGN AND METHODS

We retrospectively analyzed electronic medical record data from 37,403 surgical inpatients to assess the relationship between intraoperative blood component transfusion requirements and the case mix indexes: weighted Medicare severity DRG and weighted all-patient refined DRG. Thirty-one surgeons from the general surgery service were compared to determine correlations between blood component utilization and case mix index in both a risk unadjusted and an adjusted fashion.

RESULTS

Case mix indexes and transfusion requirements were directly correlated for red blood cells (RBCs), plasma, and platelet (PLT) transfusions (p < 0.0001 for all three blood components, for both indexes). Surgeons with greater case mix index values had greater transfusion requirements, and adjustment for case mix index resulted in less variation among surgeons (p < 0.0001, p = 0.0003, and p < 0.0001 for unadjusted vs. adjusted utilization of RBCs, plasma, and PLTs, respectively).

CONCLUSIONS

The standard DRG-based case mix indexes used to determine hospital reimbursement were strongly correlated with intraoperative transfusion requirements. We propose that these methods can be used as a risk-adjusted blood utilization metric for surgical patients.

Impact of more restrictive blood transfusion strategies on clinical outcomes: a meta-analysis and systematic review

BACKGROUND

There is accumulating evidence that restricting blood transfusions improves outcomes, with newer trials showing greater benefit from more restrictive strategies. We systematically evaluated the impact of various transfusion triggers on clinical outcomes.

METHODS

The MEDLINE database was searched from 1966 to April 2013 to find randomized trials evaluating a restrictive hemoglobin transfusion trigger of <7 g/dL, compared with a more liberal trigger. Two investigators independently extracted data from the trials. Outcomes evaluated included mortality, acute coronary syndrome, pulmonary edema, infections, rebleeding, number of patients transfused, and units of blood transfused per patient. Extracted data also included information on study setting, design, participant characteristics, and risk for bias of the included trials. A secondary analysis evaluated trials using less restrictive transfusion triggers, and a systematic review of observational studies evaluated more restrictive triggers.

RESULTS

In the primary analysis, pooled results from 3 trials with 2364 participants showed that a restrictive hemoglobin transfusion trigger of <7 g/dL resulted in reduced in-hospital mortality (risk ratio [RR], 0.74; confidence interval [CI], 0.60-0.92), total mortality (RR, 0.80; CI, 0.65-0.98), rebleeding (RR, 0.64; CI, 0.45-0.90), acute coronary syndrome (RR, 0.44; CI, 0.22-0.89), pulmonary edema (RR, 0.48; CI, 0.33-0.72), and bacterial infections (RR, 0.86; CI, 0.73-1.00), compared with a more liberal strategy. The number needed to treat with a restrictive strategy to prevent 1 death was 33. Pooled data from randomized trials with less restrictive transfusion strategies showed no significant effect on outcomes.

CONCLUSIONS

In patients with critical illness or bleed, restricting blood transfusions by using a hemoglobin trigger of <7 g/dL significantly reduces cardiac events, rebleeding, bacterial infections, and total mortality. A less restrictive transfusion strategy was not effective.

Implementation of an institutional protocol for rational use of blood products and its impact on postoperative of coronary artery bypass graft surgery

Objective:

Cardiac surgeries are sometimes followed by significant blood loss, and blood transfusions may be necessary. However, indiscriminant use of blood components can result in detrimental effects for the patient. We evaluated the short-term effects of implementation of a protocol for the rational use of blood products in the perioperative period of cardiac surgery.

Methods:

Between April and June 2011, an institutional protocol was implemented in a private hospital specializing in cardiology to encourage rational use of blood products, with the consent and collaboration of seven cardiac surgery teams. We collected clinical and demographic data on the patients. The use of blood products and clinical outcomes were analyzed during hospital stay before and after protocol implementation. The protocol consisted of an institutional campaign with an educational intervention to surgical and anesthesiology teams; the goal was to tailor blood transfusion practice according to clinical goals (anemia with hemodynamic changes and significant ventricular dysfunction) and to make routine the prescription of Ɛ-aminocaproic acid intraoperatively, which is recommended by international guidelines based on scientific evidence.

Results:

After three months of protocol implementation, the use of Ɛ-aminocaproic acid increased from 31% to 100%. A total of 67% of surgeries before protocol implementation required any blood transfusion, compared with 40% that required any blood transfusion after protocol implementation in subsequent months of the same year (p<0.001). There was no significant difference in clinical outcomes assessed before and after implementation of the protocol.

Conclusion:

The rational use of blood products associated with infusion of Ɛ-aminocaproic acid has the potential to reduce the number of blood transfusions in perioperative of cardiac surgeries, but it can affect the risk of complications.

Comparison of two tranexamic acid dose regimens in patients undergoing cardiac valve surgery

OBJECTIVE

Tranexamic acid (TA), a synthetic antifibrinolytic drug, has been shown to reduce postoperative bleeding and the need for allogeneic blood transfusion in cardiac surgery. However, the optimal dose regimen of TA is still under debate. The aim of this study was to evaluate whether a lower-dose TA regimen produced equivalent efficacy to its higher-dose counterpart in reducing postoperative bleeding and transfusion needs.

DESIGN

A prospective, randomized, double-blind trial.

SETTING

National Center for Cardiovascular Diseases & University Hospital, Beijing, People's Republic of China.

PARTICIPANTS

One hundred seventy-five patients undergoing cardiac valve surgery were enrolled in the study.

INTERVENTIONS

All patients were divided randomly into 2 groups. The lower-dose TA group received a loading dose of 10 mg/kg, maintenance dose of 2 mg/kg/h, and a cardiopulmonary bypass pump prime dose of 40 mg; the higher-dose TA group received a loading dose of 30 mg/kg, maintenance dose of 16 mg/kg/h, and a pump prime dose of 2 mg/kg.

MEASUREMENTS AND MAIN RESULTS

The amount of postoperative bleeding, the amount and frequency of allogeneic transfusion, mortality, and morbidities were recorded. There was no significant difference in the volume of 24-hour postoperative bleeding between the lower-dose group and the higher-dose group. Other measurements also showed no statistical difference between the 2 groups, including the amount and frequency of allogeneic transfusion, mortality, and morbidities.

CONCLUSION

Lower-dose TA regimen was as effective as the higher-dose regimen in reducing postoperative bleeding and transfusion needs in patients undergoing cardiac valve surgery.

Does discharge hemoglobin affect medium-term survival after coronary bypass?

BACKGROUND

the effect of discharge hemoglobin on survival of patients undergoing isolated coronary artery bypass grafting is unknown. Blood transfusion frequently confounds the issue.

METHODS

4682 consecutive patients undergoing isolated coronary artery bypass were studied. Univariate and multivariate analyses were performed to identify whether discharge hemoglobin was an independent risk factor determining survival after isolated coronary artery bypass. The analysis was complemented with a neuronal network.

RESULTS

univariate analysis identified discharge hemoglobin (p = 0.01) and blood transfusion (p < 0.0001) as significant factors affecting survival. Multivariate analysis identified age (p < 0.0001) ejection fraction (p < 0.0001), dialysis (p < 0.0001), peripheral vascular disease (p = 0.001), preoperative hemoglobin (p = 0.01), and blood transfusion (p = 0.0002) as significant factors determining survival. Neuronal network analysis confirmed the lack of importance of hemoglobin on discharge as a factor determining survival.

CONCLUSIONS

the discharge hemoglobin level does not affect medium-term survival.

Haemoglobin management in acute brain injury

PURPOSE OF REVIEW

Anaemia is common among patients in the neurocritical care unit (NCCU) and is thought to exacerbate brain injury. However, the optimal haemoglobin (Hgb) level still remains to be elucidated for traumatic brain injury (TBI), subarachnoid haemorrhage (SAH) and acute ischaemic stroke (AIS). This review outlines recent studies about anaemia and the effects of red blood cell transfusion (RBCT) on outcome in TBI, SAH and AIS patients admitted to the NCCU.

RECENT FINDINGS

Patients with severe SAH, AIS and TBI often develop anaemia and require RBCT. In general critical care, a restrictive RBCT strategy (Hgb ~7 g/dl) is preferable in patients without serious cardiac disease. In severe TBI, AIS and SAH, both anaemia and RBCT may negatively influence clinical outcome. However, the appropriate RBCT trigger remains unclear and there is great variance in how these patients are transfused. There is evidence from PET and microdialysis studies in humans that RBCT can favourably influence brain metabolism and oxygenation. This correction of hypoxia or altered metabolism rather than anaemia may be of greater importance.

SUMMARY

Results from general critical care should not be extrapolated to all patients with acute brain injury. Transfusion is not risk free, but RBCT use needs to be considered also in terms of potential benefit.