Guidelines for Perioperative Blood Transfusion and Conservation in Cardiac Surgery

Association of perioperative transfusion of fresh frozen plasma and outcomes after cardiac surgery

BACKGROUND

Fresh frozen plasma (FFP) transfusion is used to manage coagulopathy and bleeding in cardiac surgery patients despite uncertainty about its safety and effectiveness.

METHODS

We performed a propensity score matched analysis of the Australian and New Zealand Society of Cardiac and Thoracic Surgeons National Cardiac Surgery Database including patients from 39 centres from 2005 to 2018. We investigated the association of perioperative FFP transfusion with mortality and other clinical outcomes.

RESULTS

Of 119,138 eligible patients, we successfully matched 13,131 FFP recipients with 13,131 controls. FFP transfusion was associated with 30-day mortality (odds ratio (OR), 1.41; 99% CI, 1.17-1.71; p < .0001), but not with long-term mortality (hazard ratio (HR), 0.92; 99% CI, 0.85-1.00; p = .007, Holm-Bonferroni α = 0.0004). FFP was also associated with return to theatre for bleeding (OR, 1.97; 99% CI, 1.66-2.34; p < .0001), prolonged intubation (OR, 1.15; 99% CI, 1.05-1.26; p < .0001) and increased chest tube drainage (Mean difference (MD) in mL, 131; 99% CI, 120-141; p < .0001). It was also associated with reduced postoperative creatinine levels (MD in g/L, -6.33; 99% CI, -10.28 to -2.38; p < .0001).

CONCLUSION

In a multicentre, propensity score matched analysis, perioperative FFP transfusion was associated with increased 30-day mortality and had variable associations with secondary clinical outcomes.

Fresh frozen plasma transfusion after cardiac surgery

INTRODUCTION

Fresh frozen plasma (FFP) transfusion in the intensive care unit (ICU) is commonly used to treat coagulopathy and bleeding in cardiac surgery, despite suggestion that it may increase the risk of morbidity and mortality through mechanisms such as fluid overload and infection.

METHODS

We retrospectively studied consecutive adults undergoing cardiac surgery from the Medical Information Mart for Intensive Care III and IV databases. We applied propensity score matching to investigate the independent association of within-ICU FFP transfusion with mortality and other key clinical outcomes.

RESULTS

Of our 12,043 adults who met inclusion criteria, 1585 (13.2%) received perioperative FFP with a median of 2.48 units per recipient (interquartile range [IQR]: 2.04, 4.33) at a median time of 1.83 h (IQR: 0.75, 3.75) after ICU admission. After propensity matching of 952 FFP recipients to 952 controls, we found no significant association between FFP use and hospital mortality (odds ratio (OR): 1.58; 99% confidence interval (CI): 0.57, 3.71), suspected infection (OR: 0.72; 99% CI: 0.49, 1.08), or acute kidney injury (OR: 1.23; 99% CI: 0.91, 1.67). However, FFP was associated with increased days in hospital (adjusted mean difference (AMD): 1.28; 99% CI: 0.27, 2.41; p = .0050), days in intensive care (AMD: 1.28; 99% CI: 0.27, 2.28; p = .0011), and chest tube output in millilitres up to 8 h after transfusion (AMD: 92.98; 99% CI: 52.22, 133.74; p < .0001).

CONCLUSIONS

After propensity matching, FFP transfusion was not associated with increased hospital mortality, but was associated with increased length of stay and no decrease in bleeding in the early post-transfusion period.

Does training make a difference? Proficiency training in transfusion guidelines and its effect on red blood cell administration

Background

Packed red blood cell (RBC) transfusion is a very common and frequently lifesaving therapeutic intervention, but a liberal transfusion policy may be associated with inferior patient outcomes. Various guidelines have been proposed to reduce the rate of unnecessary RBC transfusions. However, physicians' proficiency in such guidelines and the effect of training on RBC administration remain unknown.

Methods

We performed a questionnaire‐based assessment of physicians' knowledge of the guidelines in a tertiary hospital in Israel, followed by an analysis of RBC administration six months before and six months after training was delivered.

Results

The level of proficiency was higher among Israeli university graduates (Odds Ratio [OR] 2.59, p‐value = 0.02), internists (OR 2.8, p‐value = 0.02), and physicians beyond the step‐one residency exam (OR 3.08, p‐value = 0.02). There was no significant effect of training on the rates of RBC administration (incidence rate ratio [IRR] = 0.96 [CI 95% 0.81–1.14], p‐value = 0.655).

Conclusion

Educational intervention alone is an ineffective means of reducing the rates of RBC administration. A more complex approach is required to prevent unnecessary RBC transfusions.

Quality Management of a Comprehensive Blood Conservation Program During Cardiopulmonary Bypass

BACKGROUND

Red blood cell transfusion is common and associated with adverse outcomes for cardiac surgery, while present blood conservation guidelines have not been fully implemented until now. This study aims to evaluate our comprehensive blood conservation program after quality management, exploring its impact on blood transfusion and outcomes in patients undergoing cardiopulmonary bypass (CPB).

METHODS

We retrospectively compared blood transfusions and outcomes of patients from two different time periods, before and after the quality management of the comprehensive blood conservation program. The comprehensive program included restrictive transfusion protocols, conventional ultrafiltration, cell salvage, residual pump blood ultrafiltration and a modified mini-extracorporeal circulation system. A 1:1 propensity score matching and subgroup analysis were conducted.

RESULTS

3977 pairs were created, a significant decrease of red cell transfusion was observed during CPB (28.4% vs 18.6%, p＜.001), in the operation (40.7% vs 34.3%, p＜.001 ) and after the operation (6.2% vs 4.3%, p＜.001). 30-day mortality and some major complications also reduced. Subgroup analysis showed that the comprehensive blood conservation program was more beneficial for the following patients: above 60, male and the medium-risk European System for Cardiac Operative Risk Evaluation (EuroSCORE) of score 3-5.

CONCLUSIONS

The comprehensive blood conservation program during CPB is safe and effective in adult cardiac surgery, reducing blood utilization with no adverse outcomes. For the patients who are older, male and EuroSCORE 3-5, blood transfusion should be more cautious.

A Systematic Review and Meta-Analysis of the Clinical Appropriateness of Blood Transfusion in China

The issue of the clinical appropriateness of blood transfusion has become a focus of transfusion medicine worldwide. In China, irrational uses of blood have often been reported in recent years. However, to date there lacks a systematic review of the rational uses of blood. This study aimed to determine the clinical appropriateness of blood transfusion in China. We searched PubMed, Web of Science, the Cochrane Library, China National Knowledge Infrastructure (CNKI), China Science and Technology Journal Database, WanFang Database, and Chinese BioMedical Literature Database, and the retrieval cut-off date was June 31, 2015. SPSS 17.0 and MetaAnalyst 3.13 were employed as the statistics tools in this review. A pooled rate of clinical inappropriateness of transfusion was analyzed by DerSimonian-Laird method. In this study, a total of 39 observational studies were included, which related to 75,132 cases of blood transfusion. According to the meta-analysis results, the overall incidence of clinical inappropriateness of transfusion in China was estimated to be 37.3% (95% confidence interval [CI] [32.1, 42.8]). The subgroup analyses revealed that the pooled rates of clinical inappropriateness of transfusion of plasma, red blood cells (RBCs), cryoprecipitate, and platelets were 56.3% (95% CI [45.8, 66.2]), 30.9% (95% CI [27.1, 35.0]), 25.2% (95% CI [13.2, 42.7]), and 14.1% (95% CI [8.8, 21.9]), respectively. However, the pooled incidence of inappropriateness of transfusion in operative departments was 47.5% (95% CI [36.8, 58.3]), which was significantly higher than that in nonoperative departments, 25.8% (95% CI [18.7, 34.4], P < 0.05). The overall rates of inappropriate use were 36.7% (95% CI [30.2, 43.6]) in major cities and 37.5% (95% CI [31.2, 44.3]) in other cities, respectively; there was no statistically significant difference (P > 0.05). In conclusion, China has suffered from a disadvantage in the clinical appropriateness of blood transfusion, especially in plasma and RBC use. In future, comprehensive measures should be implemented in order to improve the clinical appropriateness of blood transfusion.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSION

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

Compliance with guidelines for the perioperative management of vitamin K antagonists

INTRODUCTION

Perioperative vitamin K antagonist management is an issue of concern in many countries. The availability of best practice guidelines meets health professionals' needs, but compliance is uncertain and should be assessed.

MATERIALS AND METHODS

Our aim was to assess practitioner compliance with the guidelines on perioperative VKA management issued by the French National Authority for Health through a national register set up in partnership with the French College of Anaesthetists and Intensivists. Seven sections of data entry were focused on perioperative management of VKAs for elective or emergency procedures. High-risk patients were identified. Compliance with guidelines was calculated per item

RESULTS

932 charts were completed between October 2009 and December 2010. VKA therapy was interrupted in 74% (622/837) of elective procedures and bridged in 69% cases (428/622) mainly with LMWH. According to guidelines, bridging was strongly recommended in 39% high-risk patients (175/394) but 13% of these (23/175) received no bridging. Bridging was overused in 60% of low risk patients (242/406). Other compliance rates were as follows: (i) administration of therapeutic enoxaparin doses (=200IU/kg/day): only 18% of high-risk patients (18/98), (ii) INR measurement on evening prior to the procedure 65% (525/803), (iii) concomitant prothrombin complex concentrate and vitamin K administration in emergency surgery 24% (21/87), (iv) postoperative therapeutic enoxaparin doses: only 20% despite widespread prescription. The incidence rate of bleeding and thrombotic events was 7.1% and 0.96% respectively.

CONCLUSIONS

These poor compliance rates with guidelines suggest that the knowledge-to-action transfer plan was inadequate and that further interventions are required.

Improved blood utilization using real-time clinical decision support

BACKGROUND

We analyzed blood utilization at Stanford Hospital and Clinics after implementing real-time clinical decision support (CDS) and best practice alerts (BPAs) into physician order entry (POE) for blood transfusions.

STUDY DESIGN AND METHODS

A clinical effectiveness (CE) team developed consensus with a suggested transfusion threshold of a hemoglobin (Hb) level of 7 g/dL, or 8 g/dL for patients with acute coronary syndromes. The CDS was implemented in July 2010 and consisted of an interruptive BPA at POE, a link to relevant literature, and an "acknowledgment reason" for the blood order.

RESULTS

The percentage of blood ordered for patients whose most recent Hb level exceeded 8 g/dL ranged at baseline from 57% to 66%; from the education intervention by the CE team August 2009 to July 2010, the percentage decreased to a range of 52% to 56% (p = 0.01); and after implementation of CDS and BPA, by end of December 2010 the percentage of patients transfused outside the guidelines decreased to 35% (p = 0.02) and has subsequently remained below 30%. For the most recent interval, only 27% (767 of 2890) of transfusions occurred in patients outside guidelines. Comparing 2009 to 2012, despite an increase in annual case mix index from 1.952 to 2.026, total red blood cell (RBC) transfusions decreased by 7186 units, or 24%. The estimated net savings for RBC units (at $225/unit) in purchase costs for 2012 compared to 2009 was $1,616,750.

CONCLUSION

Real-time CDS has significantly improved blood utilization. This system of concurrent review can be used by health care institutions, quality departments, and transfusion services to reduce blood transfusions.

Concepts of blood transfusion in adults

Recent progress has been made in the identification and implementation of best transfusion practices on the basis of evidence-based clinical trials, published clinical practice guidelines, and process improvements for blood use and clinical patient outcomes. However, substantial variability persists in transfusion outcomes for patients in some clinical settings--eg, patients undergoing cardiothoracic surgery. This variability could be the result of insufficient understanding of published guidelines; different recommendations of medical societies, including the specification of a haemoglobin concentration threshold to use as a transfusion trigger; the value of haemoglobin as a surrogate indicator for transfusion benefit, even though only changes in concentration and not absolute red cell mass of haemoglobin can be identified; and disagreement about the validity of the level 1 evidence for clinical practice guidelines. Nevertheless, institutional experience and national databases suggest that a restrictive blood transfusion approach is being increasingly implemented as best practice.

Does rotational thromboelastometry (ROTEM) improve prediction of bleeding after cardiac surgery?

BACKGROUND

Coagulopathy and massive bleeding are severe complications of cardiac surgery, particularly in procedures requiring prolonged cardiopulmonary bypass (CPB). There is huge variability in transfusion practices across hospitals and providers in cross-sectional studies. This variability may indicate unguided decision-making, perhaps attributable to lack of reliable, predictive laboratory testing of coagulopathy to guide transfusion practice. Rotational thromboelastometry (ROTEM) measures multiple coagulation parameters and may provide value from its ease of use, rapid results, and measurement of several steps in the coagulation pathway. Yet, the predictive value and utility of ROTEM remains unclear. In this study, we investigated ROTEM's predictive value for chest tube drainage after cardiac surgery.

METHODS

Three hundred twenty-one patients undergoing cardiac surgery involving CPB were enrolled. Patient data were obtained from medical records, including chest tube output (CTO) from post-CPB through the first 8 postoperative hours. Perioperative and postoperative blood samples were collected for ROTEM analysis. Three measures of CTO were used as the primary end points for assessing coagulopathy: (i) continuous CTO; (ii) CTO dichotomized at 600 mL (75th percentile); and (iii) CTO dichotomized at 910 mL (90th percentile). Clinical and hematological variables, excluding ROTEM data, that were significantly correlated (P < 0.05) with continuous CTO were included in a stepwise regression model (model 1). An additional model that contained ROTEM variables in addition to the variables from model 1 was created (model 2). Significance in subsequent analyses was declared at P < 0.0167 to account for the 3 CTO end points. Net reclassification index was used to assess overall value of ROTEM data.

RESULTS

For continuous CTO, ROTEM variables improved the model's predictive ability (P < 0.0001). For CTO dichotomized at 600 mL (75th percentile), ROTEM did not improve the area under the receiver operating characteristic curve (AUC) (P = 0.03). Similarly, for CTO dichotomized at 910 mL (90th percentile), ROTEM did not improve the AUC (P = 0.23). Net reclassification index similarly indicated that ROTEM results did not improve overall classification of patients (P = 0.12 for CTO ≥600 mL; P = 0.08 for CTO ≥910 mL).

CONCLUSIONS

These results suggest that ROTEM data do not substantially improve a model's ability to predict chest tube drainage, beyond frequently used clinical and laboratory parameters. Although several ROTEM parameters were individually associated with CTO, they did not significantly improve goodness of fit when added to statistical models comprising only clinical and routine laboratory parameters. ROTEM does not seem to improve prediction of chest tube drainage after cardiac surgery involving CPB, although its use in guiding transfusion during cardiac surgery remains to be determined.