Red blood cell transfusion is a determinant of neurological complications after cardiac surgery

Post-transfusion severe headache in a patient with thalassemia with superficial siderosis of the central nervous system: a case report and literature review

BACKGROUND

Patients with severe thalassemia may experience adverse effects from transfusion such as fever, rash, and iron overload after long-term transfusion therapy. Severe headaches as a side effect of blood transfusion in patients with thalassemia are not commonly observed, especially when combined with superficial siderosis of the central nervous system, which is easily misdiagnosed and requires excessive examination and treatment.

CASE PRESENTATION

A 31-year-old woman was admitted with severe headache and vomiting over 3 days following blood transfusion. She was diagnosed with intermediate α-thalassemia at 2 years of age and had a history of irregular blood transfusions. Physical examination revealed horizontal nystagmus with no other abnormal neurological signs. Magnetic resonance (MR) imaging, MR venography, MR arteriography, and cerebrospinal fluid analysis were normal. However, susceptibility-weighted imaging showed abnormal signals in the bilateral and fourth ventricles. Initial antibiotics, antivirals, decompression of intracranial pressure, iron chelation, and symptomatic treatments were administered; subsequently, small intermittent blood transfusions were cautiously administered for severe anemia. The patient's headache was gradually relieved, and she was discharged on day 9. At the 5-month follow-up, the patient's headache recurred following another transfusion.

CONCLUSIONS

Severe post-transfusion headache in patients with thalassemia has not been fully recognized and is easily misdiagnosed, leading to excessive examination and treatment. Understanding the clinical features of transfusion-related headaches can help identify this complication, but the exact pathophysiological mechanism requires further research.

A comprehensive review of cerebral oximetry in cardiac surgery

BACKGROUND

Patients who undergo cardiac surgery are at increased risk of stroke, postoperative cognitive decline, and delirium. These neurocognitive complications have led to increased costs, intensive care unit stays, morbidity, and mortality. As a result, there is a significant push to mitigate any neurological complications in cardiac surgery patients. Near-infrared spectroscopy to measure regional cerebral oxygen saturations has gained consideration due to its noninvasive and user-friendly nature. Cerebral oximetry desaturations during cardiac surgery have been linked to an array of adverse clinical outcomes. However, the most effective intraoperative interventions to protect this vulnerable patient population have yet to be ascertained.

AIM OF STUDY

To provide a comprehensive summary of the intraoperative management for cerebral oximetry desaturations during cardiac surgery. The review highlights clinical outcomes from cerebral oximetry use to quantify the importance of identifying cerebral desaturations during cardiac surgery. The review then interrogates possible interventions for cerebral oximetry desaturations in an effort to determine which interventions are most efficacious and to enlighten possible areas for further research.

METHODS

A narrative review of randomized controlled trials, observational studies, and systematic reviews with metanalyses was performed through August 2021.

RESULTS

There is significant heterogeneity among patient populations for which cerebral oximetry monitoring has been studied in cardiac surgery. Further, the definition of a clinically significant cerebral desaturation and the assessment of neurocognitive outcomes varied substantially across studies. As a result, metanalysis is challenging and few conclusions can be drawn. Cerebral oximetry use during cardiac surgery has not been associated with improvements in neurocognitive outcomes, morbidity, or mortality to date. The evidence to support a particular intervention for an acute desaturation is equivocal.

CONCLUSIONS

Future research is needed to quantify a clinically significant cerebral desaturation and to determine which interventions for an acute desaturation effectively improve clinical outcomes.

Cerebral infarction after cardiac surgery

Cerebral infarction, a common central nervous system complication after adult cardiac surgery, is one of the main factors leading to the poor prognosis of cardiac surgery patients besides cardiac insufficiency. However, there is currently no effective treatment for cerebral infarction. Therefore, early prevention and diagnosis of postoperative cerebral infarction are particularly important. There are many factors and mechanisms during and after cardiac surgery that play an important role in the occurrence of postoperative cerebral infarction, such as intraoperative embolism, systemic inflammatory response syndrome, atrial fibrillation, temperature regulation, blood pressure control, use of postoperative blood products, and so forth. The mechanism by which most risk factors act on the human body, leading to postoperative cerebral infarction, is not well understood, and further research is needed. Therefore, this paper aims to summarize and explain the relevant risk factors, mechanisms, clinical signs, imaging characteristics, and early diagnosis methods of cerebral infarction complications after cardiac surgery, and provides useful data for the establishment of related diagnosis and treatment standards.

Impact of restrictive red blood cell transfusion strategy on thrombosis-related events: A meta-analysis and systematic review

BACKGROUND AND OBJECTIVES

There is an ongoing controversy regarding the risks of restrictive and liberal red blood cell (RBC) transfusion strategies. This meta-analysis assessed whether transfusion at a lower threshold was superior to transfusion at a higher threshold, with regard to thrombosis-related events, that is, whether these outcomes can benefit from a restrictive transfusion strategy is debated.

MATERIALS AND METHODS

We searched PubMed, Cochrane Central Register of Controlled Trials and Scopus from inception up to 31 July 2021. We included randomized controlled trials (RCTs) in any clinical setting that evaluated the effects of restrictive versus liberal RBC transfusion in adults. We used random-effects models to calculate the risk ratios (RRs) and 95% confidence intervals (CIs) based on pooled data.

RESULTS

Thirty RCTs involving 17,334 participants were included. The pooled RR for thromboembolic events was 0.65 (95% CI 0.44-0.94; p = 0.020; I²  = 0.0%, very low-quality evidence), favouring the restrictive strategy. There were no significant differences in cerebrovascular accidents (RR = 0.83; 95% CI 0.64-1.09; p = 0.180; I²  = 0.0%, very low-quality evidence) or myocardial infarction (RR = 1.05; 95% CI 0.87-1.26; p = 0.620; I²  = 0.0%, low-quality evidence). Subgroup analyses showed that a restrictive (relative to liberal) strategy reduced (1) thromboembolic events in RCTs conducted in North America and (2) myocardial infarctions in the subgroup of RCTs where the restrictive transfusion threshold was 7 g/dl but not in the 8 g/dl subgroup (with a liberal transfusion threshold of 10 g/dl in both subgroups).

CONCLUSIONS

A restrictive (relative to liberal) transfusion strategy may be effective in reducing venous thrombosis but not arterial thrombosis.

Total arterial coronary artery bypass grafting in patients with preoperative anemia

OBJECTIVES

Blood transfusions after coronary artery bypass grafting (CABG) has been associated to adverse outcomes, especially in anemic patients. However, little is known about the influence of the modality of revascularization. Total arterial revascularization (TAR) was shown to reduce postoperative transfusion when compared to saphenous vein-based (SV)-CABG (LIMA plus one/more SV grafts). We, therefore, aimed to investigate the impact of TAR-CABG versus SV-CABG on blood products use and perioperative outcomes in patients with preoperative anemia, normally at higher risk for postoperative transfusions.

METHODS

From a cohort of 936 patients with mild preoperative anemia undergoing primary elective on-pump CABG, 166 matched pairs of patients undergoing either TAR- or SV-CABG were obtained. Anemia was defined as hemoglobin level <13 g/dl for men and <12 g/dl for women. The primary endpoint was the evaluation of red packed cells (RPC) use over the entire hospital stay.

RESULTS

TAR patients showed significantly reduced RPC usage compared with SV (mean difference 0.45 units). TAR patients had a reduced intubation time (mean difference 7.6 h) and were discharged 1.24 days earlier than SV patients. Pneumonia and acute kidney injury were doubled among SV patients. Adjusted regression showed that TAR technique is a predictor of reduced RPC unit use regardless of age and EuroSCORE II (odds ratio: 0.63, p < .01).

CONCLUSION

Patients with preoperative anemia might benefit from TAR regardless of age or calculated operative risk. TAR-CABG was associated to reduced postoperative use of blood products and postoperative length of stay in comparison with SV-CABG in this subset of patients.

A Blinded Randomized Trial Comparing Standard Activated Clotting Time Heparin Management to High Target Active Clotting Time and Individualized Hepcon HMS Heparin Management in Cardiopulmonary Bypass Cardiac Surgical Patients

Purpose: High-dose heparin has been suggested to reduce consumption coagulopathy.

Materials and Methods: In a randomized, blinded, prospective trial of patients undergoing elective, complex cardiac surgery with cardiopulmonary bypass, patients were randomized to one of three groups: 1) high-dose heparin (HH) receiving an initial heparin dose of 450 u/kg, 2) heparin concentration monitoring (HC) with Hepcon Hemostasis Management System (HMS; Medtronic, Minneapolis, MN, USA) monitoring, or 3) a control group (C) receiving a standard heparin dose of 300 u/kg. Primary outcome measures were blood loss and transfusion requirements.

Results: There were 269 patients block randomized based on primary versus redo sternotomy to one of the three groups from August 2001 to August 2003. There was no difference in operative bleeding between the groups. Chest tube drainage did not differ between treatment groups at 8 hours (median [25th percentile, 75th percentile] for control group was 321 [211, 490] compared to 340 [210, 443] and 327 [250, 545], p = 0.998 and p = 0.540, for HH and HC treatment groups, respectively). The percentage of patients receiving transfusion was not different among the groups.

Conclusion: Higher heparin dosing accomplished by either activated clot time or HC monitoring did not reduce 24-hour intensive care unit blood loss or transfusion requirements.

Red blood cell transfusion induces abnormal HIF-1α response to cytokine storm after adult cardiac surgery

Patients undergoing cardiac surgery develop a marked postoperative systemic inflammatory response. Blood transfusion may contribute to disruption of homeostasis in these patients. We sought to evaluate the impact of blood transfusion on serum interleukin-6 (IL-6), hypoxia induced factor-1 alpha (HIF-1α) levels as well as adverse outcomes in patients undergoing adult cardiac surgery. We prospectively enrolled 282 patients undergoing adult cardiac surgery. Serum IL-6 and HIF-1α levels were measured preoperatively and on the first postoperative day. Packed red blood cells were transfused in 26.3% of patients (mean 2.93 ± 3.05 units) by the time of postoperative sampling. Postoperative IL-6 levels increased over 30-fold and were similar in both groups (p = 0.115), whilst HIF-1α levels (0.377 pg/mL vs. 0.784 pg/mL, p = 0.002) decreased significantly in patients who received red blood cell transfusion. Moreover, greater decrease in HIF-1α levels predicted worse in-hospital and 3mo adverse outcome. Red blood cell transfusion was associated with higher risk of major adverse outcomes (stroke, pneumonia, all-cause mortality) during the index hospitalization. Red blood cell transfusion induces blunting of postoperative HIF-1 α response and is associated with higher risk of adverse thrombotic and pulmonary adverse events after cardiac surgery.

Clinical Trial Registration ClinicalTrials.gov Identifier: NCT03444259.

Effect of Blood Product Transfusion on Perioperative Outcomes After Heart Transplantation

OBJECTIVE(S)

The objective of this study was to identify transfusion-related in-hospital outcomes in orthotopic heart transplantation (OHT) recipients.

DESIGN

Retrospective chart review.

SETTING

Tertiary care hospital.

PARTICIPANTS

Adult OHT recipients undergoing transplantation between January 2010 and December 2016.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

The primary composite outcome was occurrence of any of the following events during admission for OHT: (1) graft dysfunction requiring mechanical circulatory support (MCS); (2) respiratory failure requiring tracheostomy; (3) renal failure requiring hemodialysis; (4) 30-day mortality; (5) complication requiring readmission to intensive care unit; (6) sepsis; and (7) stroke. The authors evaluated these outcomes in relation to all blood component transfusions received intraoperatively and in the first 24 hours postoperatively. The study included 197 patients and the primary composite outcome was present in 72 (36.6%). After adjusting for propensity score, red blood cell (RBC) transfusion was associated with composite outcomes (odds ratio [OR] 1.17, 95% confidence interval [CI] 1.05-1.31, p = 0.004), postoperative MCS use (OR 1.36, 95% CI 1.18-1.58, p < 0.001), acute renal failure requiring hemodialysis (OR 1.21, 5% CI 1.06-1.38, p = 0.004), and 30-day mortality (OR 1.29, 95% CI 1.05-1.59, p = 0.02). Fresh frozen plasma was associated with composite outcome (OR 1.07, 95% CI [1.003-1.15], p = 0.042) and renal failure (OR 1.08, 95% CI 1.08 [1.002-1.17], p = 0.04).

CONCLUSIONS

Intra- and postoperative transfusions (first 24 hours) of RBC and FFP were associated with adverse postoperative composite outcomes in patients undergoing OHT.

Major Bleeding after Surgical Revascularization with Dual Antiplatelet Therapy

OBJECTIVE

Patients with acute coronary syndrome are treated with dual antiplatelet therapy containing acetylsalicylic acid (ASA) and P2Y12 antagonists. In case of urgent coronary artery bypass grafting this might be associated with increasing risks of bleeding complications.

METHODS

Data from 1200 consecutive urgent operations between 2010 and 2018 were obtained from our institutional patient database. For this study off-pump surgery was excluded. The primary composite end point major bleeding consisted of at least one end point: transfusion ≥ 5 packed red blood cells within 24 hours, rethoracotomy due to bleeding, chest tube output >2000 mL within 24 hours. Demographic data, peri-, and postoperative variables and outcomes were compared between patients treated with mono antiplatelet therapy, ASA + clopidogrel (ASA-C) +ticagrelor (ASA-T) or +prasugrel (ASA-P) < 72 hours before surgery. Furthermore, we compared patients with dual antiplatelet therapy with ASA monotherapy.

RESULTS

From 1,086 patients, 475 (44%) received dual antiplatelet therapy. Three-hundred seventy-two received ASA-C (77.7%), 72 ASA-T (15%), and 31 ASA-P (6.5%). Major bleeding (44 vs. 23%, p < 0.0001) was more frequently in patients receiving dual therapy with higher rates of massive drainage loss within 24 hours (23 vs. 11%, p < 0.0001) of mass transfusion (34 vs. 16%, p < 0.0001) and rethoracotomy (10 vs. 5%, p = 0.002) when compared with ASA. In this analysis, ASA-T and ASA-P were not associated with higher bleeding complications compared with ASA-C.

CONCLUSION

Dual antiplatelet therapy is associated with higher rates of major bleeding. Further studies should examine the difference in the prevalence of major bleeding complications in the different dual antiplatelet therapy regimes in patients requiring urgent surgery.

Neurological complications after cardiac surgery: anesthetic considerations based on outcome evidence

Neurological complications after cardiac surgery remain prevalent. This review aims to discuss the modifiable and outcome-relevant risk factors based on an up-to-date literature review, with a focus on interventions that may improve outcomes.

The effect of red blood cell transfusion on platelet function in critically ill patients

INTRODUCTION

Red blood cell (RBC) transfusion is associated with an increased risk of pro-thrombotic events, but the underlying mechanism is poorly understood. We hypothesized that RBC transfusion modulates platelet activity in critically ill patients with and without sepsis.

METHODS

In a prospective cohort study, 37 critically ill patients receiving a single RBC unit to correct for anemia were sampled prior to and 1 h after transfusion. Platelet exposure of P-selectin, CD63 and binding of PAC-1 as well as formation of platelet-leukocyte complexes were measured by flow cytometry. The ability of plasma from critically ill patients to induce ex vivo platelet aggregation was assessed by flow cytometry after incubation with platelets from a healthy donor.

RESULTS

RBC transfusion neither triggered the expression of platelet activation markers nor the formation of platelet-leukocyte complexes. Plasma from critically ill patients induced more spontaneous platelet aggregation prior to RBC transfusion compared to healthy controls, which was further augmented following RBC transfusion. Also collagen-induced platelet aggregation was already increased prior to RBC transfusion compared to healthy controls, and this response was unaffected by RBC transfusion. In contrast, ristocetin-induced platelet agglutination was decreased when compared to controls, suggesting impaired vWF-dependent platelet agglutination, even in the presence of high vWF levels. Following RBC transfusion, ristocetin-induced platelet agglutination further decreased. There were no differences between septic and non-septic recipients in all assays.

CONCLUSION

Ex vivo platelet aggregation is disturbed in the critically ill. Transfusion of a RBC unit may further increase the spontaneous platelet aggregatory response.

Effects of Autologous Platelet Rich Plasma on Intraoperative Transfusion and Short-Term Outcomes in Total Arch Replacement (Sun's Procedure): A Prospective, Randomized Trial

OBJECTIVE

To observe the effect of collecting and retransfusing autologous platelet rich plasma (aPRP) on the amount of allogeneic blood usage in total arch replacement (Sun's surgery) and the outcomes 30 days after surgery.

DESIGN

A prospective, randomized trial.

SETTING

A tertiary university hospital specialized in cardiovascular diseases.

PARTICIPANTS

The study comprised 120 patients undergoing Sun's surgery for Stanford type A acute aortic dissection.

INTERVENTIONS

aPRP was harvested before incision and was re-transfused after heparin neutralization for patients in the treatment group.

MEASUREMENTS AND MAIN RESULTS

There was no significant difference in preoperative demographic data between the 2 study groups. Intraoperative transfusions of erythrocyte (p = 0.009), plasma (p = 0.017), cryoprecipitate (p = 0.002), and platelets (p < 0.001) in the treatment group were reduced significantly. In addition, less blood loss was observed in the treatment group (p = 0.002). The durations of postoperative mechanical ventilation (p = 0.029) and hospitalization (p = 0.002) of the treatment group were significantly shorter. There were no statistically significant differences in the length of intensive care unit stay, the incidence of complications, and mortality 30 days after surgery.

CONCLUSION

In total arch replacement (Sun's surgery), collecting and retransfusing aPRP reduced intraoperative transfusions of erythrocyte, plasma, and cryoprecipitate and decreased the duration of postoperative mechanical ventilation and hospitalization. This technique had no significant effect on the incidence of complications and mortality 30 days postoperatively.

Prothrombin Complex Concentrate in Cardiac Surgery: A Systematic Review and Meta-Analysis

BACKGROUND

Prothrombin complex concentrate (PCC) has recently emerged as an effective alternative to fresh frozen plasma (FFP) in treating excessive perioperative bleeding. This systematic review and meta-analysis evaluated the safety and efficacy of PCC administration as first-line treatment for coagulopathy after adult cardiac surgery.

METHODS

PubMed/MEDLINE, EMBASE, and the Cochrane Library were searched from inception to the end of March 2018 to identify eligible articles. Adult patients undergoing cardiac surgery and receiving perioperative PCC were compared with patients receiving FFP.

RESULTS

A total of 861 adult patients from four studies were retrieved. No randomized studies were identified. Pooled odds ratios (ORs) showed that the PCC cohort was associated with a significant reduction in the risk of RBC transfusion (OR, 2.22; 95% confidence interval [CI], 1.45 to 3.40) and units of RBC received (OR, 1.34; 95% CI, 0.78 to 1.90). No differences were observed between the groups for reexploration for bleeding (OR, 1.09; 95% CI, 0.66 to 1.82), chest drain output at 24 hours (OR, 66.36; 95% CI, -82.40 to 216.11), hospital mortality (OR, 0.94; 95% CI, 0.59 to 1.49), stroke (OR, 0.80; 95% CI, 0.41 to 1.56), and occurrence of acute kidney injury (OR, 0.80; 95% CI, 0.58 to 1.12). A trend toward increased risk of renal replacement therapy was observed in the PCC group (OR, 0.41; 95% CI, 0.16 to 1.02).

CONCLUSIONS

In patients with significant bleeding after cardiac surgery, PCC administration seems to be more effective than FFP in reducing perioperative blood transfusions. No additional risks of thromboembolic events or other adverse reactions were observed. Randomized controlled trials are needed to establish the safety of PCC in cardiac surgery definitively.

Transfusion of autologous extracellular vesicles from stored red blood cells does not affect coagulation in a model of human endotoxemia

BACKGROUND

Red blood cell (RBC) transfusion has been related to thromboembolic events. Microvesicles in the RBC product may support coagulation because they have procoagulant effects in vitro. We investigated whether transfusion of RBCs containing extracellular vesicles promotes coagulation in human recipients. As transfusion is mostly administered to ill patients, we used a model of endotoxemia.

STUDY DESIGN AND METHODS

Eighteen healthy volunteers were randomized to receive either saline or fresh (2 days stored) or stored autologous (35 days stored) RBC transfusion (Dutch Trial Register: NTR4455). Two hours after infusion of lipopolysaccharide (LPS, from Escherichia coli, 2 ng/kg body weight), subjects received either saline or fresh or stored RBCs. Blood was sampled every 2 hours up to 8 hours after LPS infusion. Vesicles were measured with a flow cytometer (A50-Micro, Apogee Flow Systems).

RESULTS

LPS resulted in increased thrombin generation compared to baseline. During storage, the total number of extracellular vesicles increased from 1.4 × 10⁸ /mL (interquartile range [IQR], 8.3 × 10⁷ -1.9 × 10⁸ /mL) in the fresh product to 1.7 × 10¹⁰ /mL (IQR, 7.9 × 10⁹ -2.3 × 10¹⁰ /mL; p < 0.01) in the stored product (p < 0.001). Vesicles appeared to be mostly RBC derived.

CONCLUSION

After transfusion, extracellular vesicles from stored RBC products, but not from fresh products, could be detected in the circulation of healthy volunteers. However, infusion of stored RBC extracellular vesicles did not augment thrombin generation compared to endotoxemic controls. Also, levels of d-dimer and thrombin-antithrombin complex were unaffected. In conclusion, transfusion of autologous RBCs containing high levels of extracellular vesicles does not enhance coagulation in human volunteers with endotoxemia.

A model-based cost-effectiveness analysis of Patient Blood Management

BACKGROUND

Patient blood management (PBM) is a multidisciplinary concept focused on the management of anaemia, minimisation of iatrogenic blood loss and rational use of allogeneic blood products. The aims of this study were: (i) to analyse post-operative outcome in patients with liberal vs restrictive exposure to allogeneic blood products and (ii) to evaluate the cost-effectiveness of PBM in patients undergoing surgery.

MATERIALS AND METHODS

A systematic literature review and meta-analysis were performed to compare post-operative complications in predominantly non-transfused patients (restrictive transfusion group) and patients who received one to three units of red blood cells (liberal transfusion group). Outcome measures included sepsis with/without pneumonia, acute renal failure, acute myocardial infarction and acute stroke. In a second step, a health economic model was developed to calculate cost-effectiveness of PBM (PBM-arm vs control-arm) for simulated cohorts of 10,000 cardiac and non-cardiac surgical patients based on the results of the meta-analysis and costs.

RESULTS

Out of 478 search results, 22 studies were analysed in the meta-analysis. The pooled relative risk of any complication in the restrictive transfusion group was 0.43 for non-cardiac and 0.34 for cardiac surgical patients. In the simulation model, PBM was related to reduced complications (1,768 vs 1,245) and complication-related deaths (411 vs 304) compared to standard care. PBM-related costs of therapy exceeded costs of the control arm by € 150 per patient. However, total costs, including hospitalisation, were higher in the control-arm for both non-cardiac (€ 2,885.11) and cardiac surgery patients (€ 1,760.69). The incremental cost-effectiveness ratio including hospitalisation showed savings of € 30,458 (non-cardiac and cardiac surgery patients) for preventing one complication and € 128,023 (non-cardiac and cardiac surgery patients) for prevention of one complication-related death in the PBM-arm.

DISCUSSION

Our results indicate that PBM may be associated with fewer adverse clinical outcomes compared to control management and may, thereby, be cost-effective.

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.

The impact of minor blood transfusion on the outcome after coronary artery bypass grafting

PURPOSE

To investigate the impact of minor perioperative bleeding requiring transfusion of 1-2 red blood cell (RBC) units on the outcome after coronary artery bypass grafting (CABG).

METHODS

Sixteen cardiac surgical centers contributed to the prospective European CABG registry (E-CABG). 1014 patients receiving 1-2 RBC units during or after isolated CABG were compared to 2264 patients not receiving RBCs.

RESULTS

In 827 propensity score matched pairs, transfusion of 1-2 RBC units did not affect the risk of in-hospital/30-day death (p=0.523) or stroke (p=0.804). However, RBC transfusion was associated with an increased risk of acute kidney injury (p=0.008), sternal wound infection (p=0.001), postoperative use of antibiotics (p=0.001), prolonged use of inotropes (p<0.0001), use of intra-aortic balloon pump (p=0.012), length of intensive care unit stay (p<0.0001) and length of in-hospital stay (p<0.0001). Matched paired analysis excluding pre- and postoperative critical hemodynamic conditions showed that RBC transfusion was associated with an increased risk of major complications except in-hospital/30-day death.

CONCLUSION

Minor perioperative bleeding and subsequent transfusion of 1-2 RBC units did not affect the risk of early death, but increased the risk of other major adverse events. Minimizing perioperative bleeding and prevention of even low-volume RBC transfusion may improve the outcome after CABG.

Routine Application of Bloodless Priming in Neonatal Cardiopulmonary Bypass: A 3-Year Experience

A restrictive transfusion strategy led us to routinely try to conduct donor-blood free open-heart surgery even in neonates. The cardio-pulmonary bypass (CPB) circuit was minimized by priming volumina at 73 ml for the smallest patients with body weight up to 2.5 kg and 85-95 ml for those with body weight of more than 2.5 kg, and by positioning the console as close as possible to operation table. Measures were applied to save blood during the procedure. Transfusion threshold of 8 g/dl hemoglobin was retained. Effort was made to avoid transfusion while on CPB or to postpone transfusion towards CPB end. From 2013 to 2015, 149 consecutive neonates underwent 150 open-heart procedures without blood in priming volume. Weight was lower than 2.5 kg in five instances. The most frequent operations were arterial switch operation (n = 54) and Norwood procedure (n = 17). Transfusion-free operation was achieved in 44 procedures. The great majority (42/44 = 95%) involved biventricular repair and included 50% (27/54) of arterial switch operations. 106 patients were transfused: 63 mostly towards CPB end, and 43 after coming off bypass. Transfusion-free procedures were associated with postoperative lower lactate concentration (p = 0.0013) and shorter duration of mechanical ventilation (p = 0.0009). Seven patients were discharged from hospital without getting any transfusion of blood or blood products. In conclusion, routine application of bloodless priming in neonatal cardiopulmonary bypass is safe and beneficial. It results into a good number (29%= 44/150) of transfusion-free operations. Postponing transfusion towards CPB end favors an overall restrictive transfusion strategy for all patients.

Safety and efficacy of prothrombin complex concentrate as first-line treatment in bleeding after cardiac surgery

BACKGROUND

Bleeding after cardiac surgery requiring surgical reexploration and blood component transfusion is associated with increased morbidity and mortality. Although prothrombin complex concentrate (PCC) has been used satisfactorily in bleeding disorders, studies on its efficacy and safety after cardiopulmonary bypass are limited.

METHODS

Between January 2005 and December 2013, 3454 consecutive cardiac surgery patients were included in an observational study aimed at investigating the efficacy and safety of PCC as first-line coagulopathy treatment as a replacement for fresh frozen plasma (FFP). Starting in January 2012, PCC was introduced as solely first-line treatment for bleeding following cardiac surgery.

RESULTS

After one-to-one propensity score-matched analysis, 225 pairs of patients receiving PCC (median dose 1500 IU) and FFP (median dose 2 U) were included. The use of PCC was associated with significantly decreased 24-h post-operative blood loss (836 ± 1226 vs. 935 ± 583 ml, p < 0.0001). Propensity score-adjusted multivariate analysis showed that PCC was associated with significantly lower risk of red blood cell (RBC) transfusions (odds ratio [OR] 0.50; 95% confidence interval [CI] 0.31-0.80), decreased amount of RBC units (β unstandardised coefficient -1.42, 95% CI -2.06 to -0.77) and decreased risk of transfusion of more than 2 RBC units (OR 0.53, 95% CI 0.38-0.73). Patients receiving PCC had an increased risk of post-operative acute kidney injury (AKI) (OR 1.44, 95% CI 1.02-2.05) and renal replacement therapy (OR 3.35, 95% CI 1.13-9.90). Hospital mortality was unaffected by PCC (OR 1.51, 95% CI 0.84-2.72).

CONCLUSIONS

In the cardiac surgery setting, the use of PCC compared with FFP was associated with decreased post-operative blood loss and RBC transfusion requirements. However, PCC administration may be associated with a higher risk of post-operative AKI.

Assessing the Rates, Predictors, and Complications of Blood Transfusion Volume in Posterior Arthrodesis for Adolescent Idiopathic Scoliosis

STUDY DESIGN

Retrospective cohort study.

OBJECTIVE

To determine predictors of and 30-day complications associated with blood transfusion volume after posterior spinal fusion for adolescent idiopathic scoliosis (AIS).

SUMMARY OF BACKGROUND DATA

Posterior arthrodesis is a common procedure performed for AIS, and patients frequently require perioperative blood transfusions. Few studies, however, have examined the rates and potential complications associated with blood transfusion volume.

METHODS

Patients undergoing posterior arthrodesis for AIS were selected from the National Surgical Quality Improvement Program pediatric database from 2012 to 2013. Patients were stratified on the basis of blood transfusion volume and patient demographics and comorbidities, operative characteristics, and 30-day complications were recorded. Multivariate analyses were performed to determine predictors of transfusion as well as the effect of transfusion volume on 30-day complication rates.

RESULTS

A total of 1691 patients were included. Male sex (P = 0.010), esophageal or gastrointestinal disease (P = 0.016), cardiac risk factors (P = 0.037), preoperative inotrope requirement (P = 0.031), total operative time of 300 minutes or more (P < 0.001), and posterior arthrodesis of 13 or more vertebral segments (P < 0.001) were independent risk factors for requiring blood transfusion. Total transfusion volume of 20 mL/kg or more was the minimum volume independently associated with increased rates of total complications (P = 0.018), with a complication rate of 5.9%.

CONCLUSION

We present the first large, comprehensive analysis of complications related to blood transfusion events and transfusion volume on short-term postoperative complications after posterior arthrodesis for AIS. Although transfusion in general is not associated with 30-day adverse events, a volume of 20 mL/kg was associated with higher complication rates.

LEVEL OF EVIDENCE

4.

Use of Blood Products and Diseased Ascending Aorta Are Determinants of Stroke After Off-Pump Coronary Artery Bypass Grafting

OBJECTIVE

To examine the effect of blood products on the occurrence of stroke after coronary artery surgery.

DESIGN

Institutional retrospective analysis.

SETTING

University hospital.

PARTICIPANTS

One thousand three hundred fourteen patients undergoing coronary artery surgery.

INTERVENTIONS

Off-pump coronary artery bypass grafting (OPCAB). Epiaortic ultrasound was performed in all patients.

MEASUREMENTS AND MAIN RESULTS

Complete pre-, intra- and postoperative data including the number of transfused blood products as well as the timing, type, and course of stroke were available in all patients. Postoperative stroke occurred in 23 patients (1.8%). Logistic regression identified transfusion of platelets (3.6% v 1.1%, p = 0.003, OR 3.34, 95%CI 1.46-7.67) and diseased ascending aorta (3.0% v 1.2%, p = 0.022, OR 2.64, 95% CI 1.15-6.06) as independent predictors of stroke. When these variables were adjusted for CHA2DS2VASc (p = 0.005, OR 1.44, 95% CI 1.12-1.86), only transfusion of platelets (p = 0.012, OR 2.91, 95% CI 1.26-6.70) was associated with stroke. Neither nadir hematocrit on the day of surgery nor nadir hematocrit during the perioperative period was an independent predictor of stroke. Chi-squared automatic interaction detection analysis identified solvent/detergent-treated plasma (Octaplas; Octapharma AG, Lachen, Switzerland) units >2 and platelet units >4 along with diseased ascending aorta as independent predictors of stroke. The stroke rate was 8.9% in patients receiving >2 units of Octaplas and having a diseased ascending aorta. In patients receiving ≤2 units of Octaplas, the stroke rate was as high as 3.8% in patients receiving >4 units of platelets.

CONCLUSIONS

The results of this study indicated that atherosclerosis of the ascending aorta as well as transfusion of platelets and/or Octaplas were independent predictors of stroke after OPCAB.