Red blood cell transfusion: a clinical practice guideline from the AABB*

Acute coronary syndromes: Blood transfusion in patients with acute MI and anaemia

In a meta-analysis of predominantly observational data, blood transfusion was independently associated with adverse outcomes in patients with myocardial infarction. These findings are consistent with previously published research, but clinical application of these data is hindered by the lack of prospective, randomized trials and the inherent bias in observational studies.

Impact of postoperative nadir hemoglobin and blood transfusion on outcomes after operations for atherosclerotic vascular disease

OBJECTIVE

Controversy surrounds the topic of transfusion policy after noncardiac operations. This study assessed the combined impact of postoperative nadir hemoglobin (nHb) levels and blood transfusion on adverse events after open surgical intervention in patients who undergo operative intervention for atherosclerotic vascular disease.

METHODS

Consecutive patients who underwent peripheral arterial disease (PAD)-related operations were balanced on baseline characteristics by inverse weighting on propensity score calculated as their probability to have nHb greater than 10 gm/dL on the basis of operation type, demographics, and comorbidities, including the revised cardiac risk index. A multivariate generalized estimating equation analysis was performed to investigate associations between nHb, transfusion, and a composite outcome of perioperative death and myocardial infarction. Logistic and Cox proportional hazards regressions were used to assess the impact of nHb and transfusion on respiratory and wound complications; and a composite end point (CE) of death, myocardial infarction during a 2-year follow-up. Level of statistical significance was set at alpha of 0.0125 to adjust for the increased probability of type I error attributable to multiple comparisons.

RESULTS

The analysis cohort included 880 patients (1074 operations). After adjusting for nHb level, the number of units transfused was not associated with the perioperative occurrence of the CE (odds ratio [OR], 1.13; P = .025). Adjusted for the number of units transfused, nHb had no impact on the perioperative CE (OR, 0.62; P = .22). An interaction term between transfusion and nHb level remained nonsignificant (P = .312), indicating that the impact of blood transfusion was the same regardless of the nHb level. Perioperative respiratory complications were more likely in patients receiving transfusions (OR, 1.22; P = .009), and perioperative wound infections were less common in patients with nHb >10 gm/dL (OR, 0.65; P = .01). During an average follow-up of 24 months, transfused patients were more likely to develop the CE (hazard ratio [HR], 1.15, P = .009), whereas nHb level did not impact the long-term adverse event rate (HR, 0.78; P = .373). The above associations persisted even after adjusting the Cox regression model for the occurrence of perioperative cardiac events.

CONCLUSIONS

Although nHb less than 10 gm/dL is not associated with death or ACS after PAD-related operations, maintaining nHb greater than 10 gm/dL appears to decrease the risk of wound infection. Blood transfusion is associated with increased risk of perioperative respiratory complications. Until a randomized trial settles this issue definitively, a restrictive transfusion strategy is justified in patients undergoing operations for atherosclerotic vascular disease.

Repeat-dose intravenous tranexamic acid further decreases blood loss in total knee arthroplasty

PURPOSE

Tranexamic acid (TXA) reduces blood loss in patients undergoing total knee arthroplasty (TKA). However, few studies have reported the optimum timing and dosage for administration of TXA. The purpose of this study was to evaluate the effect of repeat-dose TXA on blood loss during TKA and the necessity of autologous blood donation or postoperative autotransfusion.

METHODS

We enrolled 78 patients with primary osteoarthritis undergoing cemented TKAs. Consecutive patients were divided into three groups, as follows: control group (n = 31), single-TXA group (n = 21) in whom TXA (1,000 mg) was intravenously administered 10 min before deflation of the tourniquet, and twice-TXA group (n = 26) in whom TXA (1,000 mg) was intravenously administered 10 min before deflation of the tourniquet and 3 h after the operation. We measured the volume of drained blood after the operation. Haemoglobin (Hb) levels were measured at days 1, 4 and 7 postoperation. Venous thromboembolic events (VTE) were screened using compression ultrasonography at enrollment and 1 and 7 days after operation.

RESULTS

The mean volume of drained blood after the operation was lower in the twice-TXA group than in the single-TXA (p < 0.001) and control (p < 0.0001) groups. No significant differences were observed in the incidence of VTE between these groups.

CONCLUSION

Administration of TXA twice reduced postoperative blood loss after TKA, and TXA was not associated with the risk of deep-vein thrombosis (DVT) or pulmonary embolism (PE). Further, administration of TXA twice may eliminate the need for blood transfusion during TKA.

Update in critical care for the nephrologist: transfusion in nonhemorrhaging critically ill patients

A growing number of guidelines and recommendations advocate a restrictive transfusion strategy. Strong evidence exists that a hemoglobin threshold of less than 7 g/dL conserves resources and may improve outcomes in critically ill patients and that platelet counts greater than 10,000/μL are well tolerated. Patients with coronary artery disease can be safely managed with a restrictive transfusion strategy, utilizing a hemoglobin threshold of less than 7 or 8 g/dL; a threshold of less than 8 g/dL can be applied to patients with acute coronary syndromes. In the absence of coagulopathy with bleeding or high risk for bleeding, plasma transfusion should be withheld. Complications from transfusion are significant and previously under-recognized immunologic complications pose a more serious threat than infections. Erythropoietin and iron administration do not reduce transfusion needs in the critically ill. Interventions to reduce blood loss and educate clinicians are successful in reducing transfusion requirements.

Erythropoietin or darbepoetin for patients with cancer

BACKGROUND

Anaemia associated with cancer and cancer therapy is an important clinical factor in the treatment of malignant diseases. Therapeutic alternatives are recombinant human erythropoiesis stimulating agents (ESAs) and red blood cell transfusions.

OBJECTIVES

To assess the effects of ESAs to either prevent or treat anaemia in cancer patients.

SEARCH METHODS

This is an update of a Cochrane review first published in 2004. We searched the Central Register of Controlled Trials (CENTRAL), MEDLINE and EMBASE and other databases. Searches were done for the periods 01/1985 to 12/2001 for the first review, 1/2002 to 04/2005 for the first update and to November 2011 for the current update. We also contacted experts in the field and pharmaceutical companies.

SELECTION CRITERIA

Randomised controlled trials on managing anaemia in cancer patients receiving or not receiving anti-cancer therapy that compared the use of ESAs (plus transfusion if needed).

DATA COLLECTION AND ANALYSIS

Several review authors assessed trial quality and extracted data. One review author assessed quality assessment and extracted data, a second review author checked for correctness.

MAIN RESULTS

This update of the systematic review includes a total of 91 trials with 20,102 participants. Use of ESAs significantly reduced the relative risk of red blood cell transfusions (risk ratio (RR) 0.65; 95% confidence interval (CI) 0.62 to 0.68, 70 trials, N = 16,093). On average, participants in the ESAs group received one unit of blood less than the control group (mean difference (MD) -0.98; 95% CI -1.17 to -0.78, 19 trials, N = 4,715). Haematological response was observed more often in participants receiving ESAs (RR 3.93; 95% CI 3.10 to 3.71, 31 trials, N = 6,413). There was suggestive evidence that ESAs may improve Quality of Life (QoL). There was strong evidence that ESAs increase mortality during active study period (hazard ratio (HR) 1.17; 95% CI 1.06 to 1.29, 70 trials, N = 15,935) and some evidence that ESAs decrease overall survival (HR 1.05; 95% CI 1.00 to 1.11, 78 trials, N = 19,003). The risk ratio for thromboembolic complications was increased in patients receiving ESAs compared to controls (RR 1.52, 95% CI 1.34 to 1.74; 57 trials, N = 15,498). ESAs may also increase the risk for hypertension (fixed-effect model: RR 1.30; 95% CI 1.08 to 1.56; random-effects model: RR 1.12; 95% CI 0.94 to 1.33, 31 trials, N = 7,228) and thrombocytopenia/haemorrhage (RR 1.21; 95% CI 1.04 to 1.42; 21 trials, N = 4,507). There was insufficient evidence to support an effect of ESA on tumour response (fixed-effect RR 1.02; 95% CI 0.98 to 1.06, 15 trials, N = 5,012).

AUTHORS' CONCLUSIONS

ESAs reduce the need for red blood cell transfusions but increase the risk for thromboembolic events and deaths. There is suggestive evidence that ESAs may improve QoL. Whether and how ESAs affects tumour control remains uncertain. The increased risk of death and thromboembolic events should be balanced against the potential benefits of ESA treatment taking into account each patient's clinical circumstances and preferences. More data are needed for the effect of these drugs on quality of life and tumour progression. Further research is needed to clarify cellular and molecular mechanisms and pathways of the effects of ESAs on thrombogenesis and their potential effects on tumour growth.

Hemoglobin level at initiation of darbepoetin alfa: impact on need for transfusion and associated costs in chemotherapy-induced anemia treatment in Europe

PURPOSE

Erythropoiesis-stimulating agents can reduce red blood cell transfusion rates in patients developing anemia while receiving chemotherapy. We investigated potential cost savings from reduced transfusion rates in patients starting darbepoetin alfa (DA) at higher versus lower hemoglobin (Hb) levels.

METHODS

Two systematic literature reviews were performed: transfusion outcomes in patients receiving DA stratified by baseline Hb level and costs of transfusion in Europe. Potential cost savings were calculated by multiplying the difference in transfusion rates between Hb levels by the midpoint of transfusion costs.

RESULTS

Despite differences in baseline characteristics, treatment duration and analysis technique, the clinical studies (n = 8) showed that fewer transfusions were required when DA was initiated at higher versus lower Hb levels. The economic studies (n = 9) showed that 1 unit of transfusion ranged from <euro>130 to <euro>537 (2010-adjusted values). Cost savings from initiating DA at higher versus lower Hb levels were <euro>503-2,226 (2 units transfused) and <euro>880-3,895 (3.5 units) per ten patients.

CONCLUSIONS

Transfusion incidence increases with DA initiation at lower Hb levels. Potential cost savings depend on the number of units transfused and cost items included. DA initiation according to guidelines can reduce transfusions and potentially reduce transfusion-associated costs.