Transfusion and outcome in heart surgery

The Impact of Pre-Heart Transplantation Blood Transfusion Varies Based on Recipient MELD-XI Score

Prior studies reveal adverse effects of transfusion on cardiac surgery, but little is known of transfusion impact on heart transplantation. First-time, single-organ adult heart transplant recipients between January 1, 2010, and December 31, 2020, were included, stratified above or below a model for end-stage liver disease excluding international normalized ratio (MELD-XI) score of 9.4, and propensity score matched to their nearest neighbor. A 90 day landmark analysis within each cohort was also performed. Unadjusted analysis showed transfusion recipients, MELD-XI ≥9.4, were more likely to experience post-heart transplantation mortality (Hazard Ratio (HR), 1.352 [95% Confidence Interval (CI), 1.239-1.477], p < 0.001), persisting after adjustment for potential confounders (adjusted HR, 1.211 [95% CI, 1.100-1.335], p < 0.001) and after propensity-score matching (HR, 1.174 [95% CI, 1.045-1.319], p = 0.007). Post-transplant length of stay was longer (25.9 vs. 23.2 days, p < 0.001). Post-transplant dialysis was more common (18.7 vs. 15.9%, p = 0.009). There was no survival difference on 90 day landmarked analysis ( p = 0.108). With MELD-XI <9.4, there was slight survival detriment among transfusion recipients on univariable analysis (HR, 1.111 [95% CI, 1.001-1.234], p = 0.049) but not on multivariable analysis (adjusted HR, 1.061 [95% CI, 0.952-1.181], p = 0.285). There was similar survival after propensity-score matching (HR, 1.032 [95% CI, 0.903-1.180], p = 0.642) and on landmark analysis ( p = 0.581). Ultimately, transfusion was associated with worse post-heart transplantation outcomes among recipients with a MELD-XI ≥9.4.

Perioperative Mass Transfusion Affects In-Hospital but Not Follow-Up Survival in Patients with Acute Type A Aortic Dissection

Background and Objectives: The aim of this study was to analyze the influence of mass transfusion on the postoperative outcome and survival in patients presenting with acute Type A aortic dissection. Materials and Methods: Between 2002 and 2020, a total of 505 patients were surgically treated for an acute Type A aortic dissection. Mass transfusion was defined as the peri- and postoperative replacement by transfusion of 10 units. Patient characteristics and outcomes were analyzed and compared between patients with and without mass transfusion. Results: Mass transfusion occurred in 105 patients (20%). The incidences of symptomatic coronary malperfusion (p = 0.017) and tamponade (p = 0.043) were higher in patients with mass transfusion. There was no statistically significant difference in the distal extension of the aortic dissection between the two groups. A valved conduit was significantly more common in patients with mass transfusion (p = 0.007), while the distal aortic repair was similar between the two groups. Cardiopulmonary bypass time (p < 0.001), cross clamp time (p < 0.001) and in-hospital mortality were significantly higher in patients with mass transfusion (p < 0.001), but the survival after discharge (landmark-analysis) showed equal survival between patients with and without mass transfusion (log rank: p = 0.4). Mass transfusion was predictive of in-hospital mortality (OR: 3.308, p < 0.001) but not for survival after discharge (OR: 1.205, p = 0.661). Conclusions: Mass transfusion is necessary in many patients with acute Type A aortic dissection. These patients present sicker and require longer surgery. However, mass transfusion does not influence survival after discharge.

Review of Thromboelastography (TEG): Medical and Surgical Applications

Thromboelastography (TEG) is a laboratory assay utilized to evaluate hemostatic properties of blood, identify coagulopathy, and guide blood product administration. While the clinical use of TEG started in the care of surgical patients, the assay has now been incorporated more routinely in the care of the medical patient as well. In this review, we explore the evolution of TEG from the historical perspective of its inception to the current state of the art of the assay. The TEG procedure and its measurements are illustrated along with a table that summarizes recommendations from across the medical and surgical literature. After each section, we review salient learning points to provide the busy clinician with information that can be immediately integrated at the bedside. We conclude with a series of summary questions to check for comprehension and direct the reader to additional resources to improve their knowledge of TEG.

Perioperative Anemia and Transfusions and Late Mortality in Coronary Artery Bypass Patients

BACKGROUND

Perioperative anemia and transfusions are associated with adverse operative outcomes after coronary artery bypass graft surgery (CABG). Their individual association with long-term outcomes is unclear.

METHODS

Patients aged 65 years and older who had undergone CABG and were in The Society of Thoracic Surgeons (STS) Adult Cardiac Surgery Database (n = 504,596) from 2011 to 2018 were linked to Centers for Medicare and Medicaid Service data to assess long-term survival. The association of intraoperative anemia defined by intraoperative nadir hematocrit (nHct) and red blood cell (RBC) transfusions, and their interactions, on long-term mortality were assessed with Kaplan-Meier estimates and multivariable Cox regression. Restricted cubic splines were used to explore the association between nHct as a continuous variable and long-term mortality.

RESULTS

258,398 on-pump CABG STS Adult Cardiac Surgery Database patients surviving the perioperative period were linked to Centers for Medicare and Medicaid Service claims files. Per World Health Organization criteria, 41% had preoperative anemia. Mean intraoperative nHct was 24%; RBC transfusion rate was 43.7%. Univariable analysis associated both RBC transfusion and lower nHct with worse survival. Lower nHct was only marginally associated with risk-adjusted mortality: adjusted hazard ratio (AHR) 1.04 (95% CI, 1.01-1.06) and 1.07 (95% CI, 1.00-1.14) at nHct 20% and at nHct 14%, respectively. RBC transfusion was associated with significantly higher adjusted mortality irrespective of timing of transfusion: AHR intraoperative 1.21 (95% CI, 1.18-1.27); AHR postoperative 1.26 (95% CI, 1.22-1.30); AHR both 1.46 (95% CI, 1.40-1.52) and across all levels of nHct. RBC transfusion was not associated with improved survival at any level of nHct.

CONCLUSIONS

Among Medicare CABG patients, RBC transfusions were associated with increased risk-adjusted late mortality across all levels of nHct whereas intraoperative anemia was only marginally so. Tolerance of lower intraoperative nHct than currently accepted may be preferable to transfusions.

The use of blood and blood products in aortic surgery is associated with adverse outcomes

OBJECTIVE

To report long-term outcomes after deep hypothermic circulatory arrest (DHCA) with or without perioperative blood or blood products.

METHODS

All patients who underwent proximal aortic surgery with DHCA from 2011 to 2018 were propensity matched according to baseline characteristics. Primary outcomes included short- and long-term mortality. Stratified Cox regression analysis was performed for significant associations with survival.

RESULTS

A total of 824 patients underwent aortic replacement requiring circulatory arrest. After matching, there were 224 patients in each arm (transfusion and no transfusion). All baseline characteristics were well matched, with a standardized mean difference (SMD) <0.1. Preoperative hematocrit (41.0 vs 40.6; SMD = 0.05) and ejection fraction (57.5% vs 57.0%; SMD = 0.08) were similar between the no transfusion and blood product transfusion cohorts. Rate of aortic dissection (42.9% vs 45.1%; SMD = 0.05), hemiarch replacement (70.1% vs 70.1%; SMD = 0.00), and total arch replacement (21.9% vs 23.2%; SMD = 0.03) were not statistically different. Cardiopulmonary bypass and cross-clamp time were higher in the blood product transfusion cohort (P < .001). Operative mortality (9.4% vs 2.7%; P = .003), stroke (7.6% vs 1.3%; P = .001), reoperation rate, pneumonia, prolonged ventilation, and dialysis requirements were significantly higher in the transfusion cohort (P < .001). In stratified Cox regression, transfusion was an independent predictor of mortality (hazard ratio, 2.62 [confidence interval, 1.47-4.67]; P = .001). One- and 5-year survival were significantly reduced for the transfusion cohort (P < .001).

CONCLUSIONS

In patients who underwent aortic surgery with DHCA, perioperative transfusions were associated with poor outcomes despite matching for preoperative baseline characteristics.

Factor eight inhibiting bypass activity for refractory bleeding in acute type A aortic dissection repair: A propensity-matched analysis

BACKGROUND

Perioperative bleeding and transfusion have been associated with adverse outcomes after cardiac surgery. The use of factor eight inhibiting bypass activity (FEIBA) in managing bleeding after repair of acute Stanford type A aortic dissection (ATAAD) has not previously been evaluated. We report our experience in utilizing FEIBA in ATAAD repair.

STUDY DESIGN AND METHODS

A retrospective review was undertaken of all consecutive patients who underwent repair of ATAAD between July 2014 and December 2019. Patients were divided into two groups, dependent upon whether or not they received FEIBA intraoperatively: "FEIBA" (n = 112) versus "no FEIBA" (n = 119). From this, 53 propensity-matched pairs of patients were analyzed with respect to transfusion requirements and short-term clinical outcomes.

RESULTS

Thirty-day mortality for the entire cohort was 11.7% (27 deaths), not significantly different between patient groups. Those patients who received FEIBA demonstrated reduced transfusion requirements for all types of blood products in the first 48 h after surgery as compared with the "no FEIBA" cases, including red blood cells, platelets, plasma, and cryoprecipitate (p < .0001). There was no significant difference in major postoperative morbidity between the two groups. The FEIBA cohort did not demonstrate an increased incidence of thrombotic complications (stroke, deep venous thrombosis, pulmonary thromboembolism).

DISCUSSION

When used as rescue therapy for refractory bleeding following repair of ATAAD, FEIBA appears to be effective in decreasing postoperative transfusion requirements whilst not negatively impacting clinical outcomes. These findings should prompt further investigation and validation via larger, multi-center, randomized trials.

Impact of a Hemoglobin Trigger Communication Tool on Perioperative Transfusion in Cardiac Surgery

OBJECTIVES

Blood transfusion represents an important and potentially modifiable risk in the daily practice of cardiac surgery. The risk profile and increasing cost of transfusion led us to study the effect of different maneuvers, interventions, or surgical techniques to minimize transfusion while maintaining patient safety. This study compares postoperative outcomes before and after incorporating a verbal hemoglobin (Hb) trigger during the surgical timeout in which the surgeon and anesthesiologist preemptively agree on a threshold for packed red blood cell (PRBC) administration in the perioperative period.

METHODS

The authors performed a chart review of patients who underwent cardiac surgery from July 2013 through June 2014 at our institution. Patients who underwent surgery from July 2013 through December 2013 served as the pre-Hb trigger group, and patients who underwent surgery from January 2014 through June 2014 served as the post-Hb trigger group. Information collected included patient demographics, type of cardiac surgery, preoperative Hb, Hb trigger, and intraoperative and postoperative variables. The primary outcome was the incidence of PRBC transfusions. Secondary outcomes included the incidence of frozen plasma (FP) transfusion, mechanical ventilation beyond postoperative day 1, and 30-day mortality.

RESULTS

The study included 191 patients, with 84 in the pre-Hb trigger group and 107 in the post-Hb trigger group. Intraoperative PRBC transfusions did not decrease in the posttrigger group compared with the pretrigger group (pretrigger 51.4% vs posttrigger 52.4%, P = 1.0); however, intraoperative FP administration was lower in the posttrigger group (65.4% vs 50.0%, P = 0.038). Postoperative mechanical ventilation beyond postoperative day 1 also was significantly lower in the posttrigger group compared with the pretrigger group (27.1% vs 14.3%, P = 0.035).

CONCLUSIONS

Implementation of a verbal Hb trigger during the surgical timeout was associated with a reduction in FP administration and duration of mechanical ventilation, but not a decrease in PRBC transfusion and mortality.

Transfusion in Elective Proximal Aortic Reconstruction: Where Do We Currently Stand?

Aortic procedures are associated with higher risks of bleeding, yet data regarding perioperative transfusion in this patient population are lacking. We evaluated transfusion patterns in patients undergoing proximal aortic surgery to provide a benchmark against which future standards can be assessed. Between June 2014 and July 2017, 247 patients underwent elective aortic reconstruction for aneurysm. Patients with acute aortic syndrome, endocarditis, and/or prior cardiac surgery were excluded. Transfusion data were analyzed by type of operation: ascending aorta replacement ± aortic valve procedure (group 1, n  = 122, 49.4%); aortic root replacement with a composite valve-graft conduit ± ascending aorta replacement (group 2, n  = 93, 37.7%); valve-sparing aortic root replacement (VSARR) ± ascending aorta replacement (group 3, n  = 32, 13.0%). Thirty-day mortality for the entire cohort was 2.02% (5 deaths). Overall, 75 patients (30.4%) did not require any transfusion of blood or other products. Patients in groups 1 and 3 were significantly more likely to avoid transfusion than those in group 2. Mean transfusion volume for any individual patient was modest; those who underwent VSARR (group 3) required less intraoperative red blood cells (RBC) than others. Intraoperative transfusion of RBC was independently associated with an increased risk of death at 30 days. Elective proximal aortic reconstruction can be performed without the need for excessive utilization of blood products. Composite root replacement is associated with a greater need for transfusion than either VSARR or isolated replacement of the ascending aorta.

Retrograde autologous priming in cardiac surgery: a systematic review and meta-analysis

OBJECTIVES

Guidelines recommend retrograde autologous priming (RAP) of the cardiopulmonary bypass circuit. However, the efficacy and safety of RAP is not well-established. We performed a systematic review and meta-analysis to determine the effects of RAP on transfusion requirements, morbidity and mortality.

METHODS

We searched Cochrane Central Register of Controlled Trials, Medline, ScienceDirect, Cumulative Index to Nursing and Allied Health Literature and Embase for randomized controlled trials (RCTs) and observational studies comparing RAP to no-RAP. We performed title and abstract review, full-text screening, data extraction and risk of bias assessment independently and in duplicate. We pooled data using a random effects model.

RESULTS

Twelve RCTs (n = 1206) and 17 observational studies (n = 3565) were included. Fewer patients required blood transfusions with RAP [RCTs; risk ratio 0.58 [95% confidence interval (CI): 0.51, 0.65], P < 0.001, and observational studies; risk ratio 0.65 [95% CI: 0.53, 0.80], P < 0.001]. The number of units transfused per patient was also lower among patients who underwent RAP (RCTs; mean difference -0.38 unit [95% CI: -0.72, -0.04], P = 0.03, and observational studies; mean difference -1.03 unit [95% CI: -1.76, -0.29], P < 0.006).

CONCLUSIONS

This meta-analysis supports the use of RAP as a blood conservation strategy since its use during cardiopulmonary bypass appears to reduce transfusion requirements.

A prognostic model for the preoperative identification of patients at risk for receiving transfusion of packed red blood cells in cardiac surgery

BACKGROUND

Patients undergoing cardiothoracic surgery are at substantial risk for blood transfusion. Increased awareness and patient blood management have resulted in a significant reduction over the past years. The next step is preoperative treatment of patients at high risk for packed red blood cells (RBC) transfusion, with the ultimate goal to eventually prevent RBC transfusion. A prediction model was developed to select patients at high risk for RBC transfusion.

MATERIALS AND METHODS

Data of all patients that underwent cardiac surgery in our center between 2008 and 2013 (n = 2951) were used for model development, and between 2014 and 2016 for validation (n = 1136). Only preoperative characteristics were included in a multinomial regression model with three outcome categories (no, RBC, other transfusion). The accuracy of the estimated risks and discriminative ability of the model were assessed. Clinical usefulness was explored.

RESULTS

Risk factors included are sex, type of surgery, redo surgery, age, height, body mass index, preoperative hemoglobin level, and preoperative platelet count. The model has excellent discriminative ability for predicting RBC transfusion versus no transfusion (area under the curve [AUC] = 94%) and good discriminative ability for RBC transfusion versus other transfusion (AUC = 84%). With a cut-off value of RBC risk of 16.8% and higher, the model is well able to identify a high proportion of patients at risk for RBC transfusion (sensitivity = 87.1%, specificity = 82.3%).

CONCLUSION

In the current study, a prediction tool was developed to be used for risk stratification of patients undergoing elective cardiac surgery at risk for blood transfusions.

Long-term Impact of Perioperative Red Blood Cell Transfusion on Patients Undergoing Cardiac Surgery

BACKGROUND

There is a known association between need for transfusion and short-term outcomes in patients undergoing cardiac surgery. However long-term data are lacking in the contemporary literature.

METHODS

All patients who underwent open cardiac surgery from 2010 to 2018 were included, except those undergoing transplant, with a ventricular-assist device, and requiring circulatory arrest. Primary outcome included short- and long-term mortality. Secondary outcomes included postoperative complications and hospital readmissions.

RESULTS

The total patient population included 14,281 patients with a median follow-up of 4.03 years (range, 2.25-6.1). Outcomes were stratified into patients with (n = 6239) or without (n = 8042) packed red blood cell (PRBC) use. Patients with PRBC transfusions had significantly (P < .001) worse postoperative outcomes compared with those without PRBC use, including higher operative mortality (6.89% vs 0.98%), return to the operating room (17.8% vs 1.61%), pneumonia (7.84% vs 0.98%), stroke (3.22% vs 1.51%), sepsis (2.66% vs 0.20%), renal failure (8.42% vs 1.12%), and dialysis (5.74% vs 0.42%). On multivariate analysis PRBC transfusion was an independent predictor of mortality (hazard ratio [[HR], 2.39; 95% confidence interval [CI], 2.08-2.64; P < .001) and hospital readmission (HR, 1.15; 95% CI, 1.09-1.21; P < .001). Total units of PRBCs were directly associated with mortality (HR, 1.09; 95% CI, 1.08-1.09; P < .001) and hospital readmissions (HR, 1.02; 95% CI, 1.01-1.03; P < .005).

CONCLUSIONS

Patients with perioperative PRBC transfusions have increased operative and long-term mortality and hospital readmissions. Total units of PRBCs transfused were directly associated with mortality and readmissions.

Potential Consequences of the Red Blood Cell Storage Lesion on Cardiac Electrophysiology

Background The red blood cell (RBC) storage lesion is a series of morphological, functional, and metabolic changes that RBCs undergo following collection, processing, and refrigerated storage for clinical use. Since the biochemical attributes of the RBC unit shifts with time, transfusion of older blood products may contribute to cardiac complications, including hyperkalemia and cardiac arrest. We measured the direct effect of storage age on cardiac electrophysiology and compared it with hyperkalemia, a prominent biomarker of storage lesion severity. Methods and Results Donor RBCs were processed using standard blood-banking techniques. The supernatant was collected from RBC units, 7 to 50 days after donor collection, for evaluation using Langendorff-heart preparations (rat) or human induced pluripotent stem cell-derived cardiomyocytes. Cardiac parameters remained stable following exposure to "fresh" supernatant from red blood cell units (day 7: 5.8±0.2 mM K+), but older blood products (day 40: 9.3±0.3 mM K+) caused bradycardia (baseline: 279±5 versus day 40: 216±18 beats per minute), delayed sinus node recovery (baseline: 243±8 versus day 40: 354±23 ms), and increased the effective refractory period of the atrioventricular node (baseline: 77±2 versus day 40: 93±7 ms) and ventricle (baseline: 50±3 versus day 40: 98±10 ms) in perfused hearts. Beating rate was also slowed in human induced pluripotent stem cell-derived cardiomyocytes after exposure to older supernatant from red blood cell units (-75±9%, day 40 versus control). Similar effects on automaticity and electrical conduction were observed with hyperkalemia (10-12 mM K+). Conclusions This is the first study to demonstrate that "older" blood products directly impact cardiac electrophysiology, using experimental models. These effects are likely caused by biochemical alterations in the supernatant from red blood cell units that occur over time, including, but not limited to hyperkalemia. Patients receiving large volume and/or rapid transfusions may be sensitive to these effects.

Association Between Post-Operative Infection and Blood Transfusion in Cardiac Surgery

Background

Blood transfusion is a commonly used therapy in cardiac surgery, whether it is given during the surgery or in the intensive care unit. It is important to evaluate the risks and benefits of exposure to blood transfusion. The use of blood transfusions can influence patient outcome. Previous studies have implicated blood transfusion as a causative factor in post-operative infection.

Objectives

We aim to determine the effect of blood transfusion on post-operative infection in cardiac surgery patients at the King Faisal Cardiac Center, Jeddah, Saudia Arabia, from January 2017 to January 2019.

Methods

The regular six-week follow-up of cardiac surgery patients allowed us to maintain a six-week infection span. The main variables included patient characteristics, operative characteristics, pre-operative hemoglobin, six-week infection, blood transfusion, and clinical outcomes. A logistic regression model was developed to identify patient and procedure variables that were associated with blood transfusion and infection. The baseline variables were entered into the model. Variables with p-value less than 0.05 were considered significant.

Results

The incidence of transfusion out of 197 patients was 93.4% (n = 184). The occurrence of infection was 31.82% (n = 63). There was no difference in post-operative infection for patients who received blood transfusions compared with those who did not receive blood transfusions (p = 0.902). In comparing patients receiving 1-2 units of red blood cells (RBCs) (48%) and those receiving >2 units of RBCs (52%), there was no significance (p = 0.549).

Conclusions

There was no association between the incidence of infection and blood transfusion. While there are other reasons for withholding blood, it would not be recommended to do so based on the concern of infection.

Determinants of hospital variability in perioperative red blood cell transfusions during coronary artery bypass graft surgery

OBJECTIVE

To identify to what extent distinguishing patient and procedural characteristics can explain center-level transfusion variation during coronary artery bypass grafting surgery.

METHODS

Observational cohort study using the Perfusion Measures and Outcomes Registry from 43 adult cardiac surgical programs from July 1, 2011, to July 1, 2017. Iterative multilevel logistic regression models were constructed using patient demographic characteristics, preoperative risk factors, and intraoperative conservation strategies to progressively explain center-level transfusion variation.

RESULTS

Of the 22,272 adult patients undergoing isolated coronary artery bypass surgery using cardiopulmonary bypass, 7241 (32.5%) received at least 1 U allogeneic red blood cells (range, 10.9%-59.9%). When compared with patients who were not transfused, patients who received at least 1 U red blood cells were older (68 vs 64 years; P < .001), were women (41.5% vs 15.9%; P < .001), and had a lower body surface area (1.93 m² vs 2.07 m²; P < .001), respectively. Among the models explaining center-level transfusion variability, the intraclass correlation coefficients were 0.07 for model 1 (random intercepts), 0.12 for model 2 (patient factors), 0.14 for model 3 (intraoperative factors), and 0.11 for model 4 (combined). The coefficient of variation for center-level transfusion rates were 0.31, 0.29, 0.40, and 0.30 for models 1 through 4, respectively. The majority of center-level variation could not be explained through models containing both patient and intraoperative factors.

CONCLUSIONS

The results suggest that variation in center-level red blood cells transfusion cannot be explained by patient and procedural factors alone. Investigating organizational culture and programmatic infrastructure may be necessary to better understand variation in transfusion practices.

Blood transfusion and lung surgeries in pediatric age group: A single center retrospective study

Background:

Blood transfusion is not without harm, and recent studies suggest association between transfusion and poor outcome in critically ill patients. Although it is prescribed for many reasons based on the firm belief that blood transfusion improves oxygen carrying capacity, it carries notable adverse hazards. Importantly, lung surgeries are counted as moderate to high-risk operations and take a significant risk of blood loss.

Aim:

This study aims to reveal the association between blood transfusion and poor clinical outcomes and characterize the epidemiology of blood transfusion after pediatric chest surgery.

Settings and Design:

Retrospective cohort study, done throughout 3 years.

Materials and Methods:

A total of 248 patients who underwent open thoracotomy and lung surgery and aged ≤18 years were classified according to the need of intraoperative or postoperative blood transfusion into two groups: Group I (non-transfused = 130) and Group II (transfused = 118).

Statistical Analysis:

SPSS v25 was used for analysis.

Results:

Transfusion probability ranged between 42.8% and 50% according to type of surgery. As regard to postoperative variables, there was no significant difference between both groups regarding the duration of analgesia, allergic reactions, need of re-operation and in-hospital mortality. However, transfused group showed significant increase in duration of antibiotic, persistent postoperative fever, time to remove chest drains, ICU stays, hospital stay and pneumonia. Incidence of pneumonia had a relative risk 1.82 with transfused compared to non-transfused group.

Conclusion:

Transfusion group in pediatrics undergoing lung surgeries in our study was more prone to adverse outcomes such as pneumonia, delayed time to remove chest drains, prolonged ICU stay, and hospital stay.

Prospective Evaluation of a Blood Transfusion Protocol for Patients Undergoing Cardiac Operations

BACKGROUND

The Society of Thoracic Surgeons clinical practice guidelines recommend the creation of an interdisciplinary blood management team to implement protocols for improved blood transfusion practices. We report our center's prospective evaluation of a blood transfusion protocol.

METHODS

An interdisciplinary blood management team developed protocols for transfusion of packed red blood cells, fresh frozen plasma, platelets, and cryoprecipitate. The protocols were prospectively evaluated by tracking transfusions administered to consecutive patients undergoing cardiac operations, and the primary outcome of interest was the mean number of adjusted units of blood product transfused per patient. Protocol implementation phases were separated by washout phases to control for a potential Hawthorne effect associated with protocol implementation. Protocol compliance was also assessed.

RESULTS

A total of 1441 patients underwent cardiac operations during the 16-month study period. Although there was no statistically significant reduction in transfusions with an unadjusted analysis, there was a significant trend toward a reduction of the mean adjusted total units transfused per patient over the course of the study period (P < .001). The mean adjusted total units transfused per patient were significantly less during the second washout phase (2.8 units; 95% confidence interval [CI], 2.3-3.3) and second protocol phase (2.8 units; 95% CI, 2.32-3.27) compared with the initial baseline survey phase (3.6 units, 95% CI, 3.1-4.1; P < .05 for both comparisons). Only 55.2% of all units were transfused in compliance to the implemented protocols: platelets, 46.8%; cryoprecipitate, 32.1%; packed red blood cells, 60.7%; and fresh frozen plasma, 53.6%.

CONCLUSIONS

During a prospective evaluation of blood transfusion protocols, a risk-adjusted analysis demonstrated a reduction in transfusions despite poor protocol compliance.

Utilisation of blood and blood products during open heart surgery in a low-income country: our local experience in 3 years

BACKGROUND

In Nigeria, access to open heart surgery (OHS) is adversely affected by insufficient blood and blood products, including the challenges because of the lack of patient-focused blood management strategies owing to the absent requisite point-of-care tests in the operating theatre (OR)/ICU. In addition, the limited availability of altruistic blood donors including the detection of transfusion transmitted infections more commonly among non-altruistic blood donors is another burden affecting the management of excessive bleeding during and after open heart surgery in our country.

OBJECTIVE

The objective of this study was to review our local experience in the use of blood and blood products during open heart surgery and compare the same with the literature.Materials and methodsIn a period of 3 years (March, 2013-February, 2016), we performed a retrospective review of those who had open heart surgery in our institution. The data were obtained from our hospital health information technology department. The data comprised demography, types of operative procedures and units of blood and blood products transfused per procedure, including the details regarding the usage of the cell saver, as well as those who had severe bleeding requiring excessive blood transfusion.

RESULTS

During the study period, 102 patients had open heart surgery, an average of 34 cases in a year. Among them, there were 75 (73.53%) males and 37 (36.27%) females, giving a ratio of 2:1. The ages of the patients were from 0.6 (7/12) to 74 years. Mitral valve procedure was the most common (n=22, 21.6%) surgery type. Transfusion requirements averaged 1.9 units of fresh frozen plasma, 0.36 units of platelet concentrate, and 1.68 units of packed cells per procedure. The least common surgical procedure was common atrium repair (n=1, 0.01%).

CONCLUSION

Open heart procedure is a very complex procedure requiring cardiopulmonary bypass with associated severe perioperative bleeding. The attendant blood loss and haemostatic challenges are combated by intricate and selective transfusions of allogeneic blood and or blood products.

Early Versus Late Tracheostomy in Cardiac Surgical Patients: A 12-Year Single Center Experience

OBJECTIVES

To evaluate whether early tracheostomy is associated with better outcomes in mechanical ventilation-dependent patients after cardiac surgery compared with a late tracheostomy.

DESIGN

Retrospective, observational study.

SETTING

Cardiac surgical intensive care unit (ICU) of a tertiary care center.

PARTICIPANTS

All patients who underwent tracheostomy after cardiac surgery between 2004 and 2015 were subdivided into the following 2 groups according to the timing of tracheostomy: "early" if the tracheostomy was performed before the 14th postoperative day and "late" from the 14th postoperative day onward.

INTERVENTIONS

Early versus late tracheostomy.

MEASUREMENTS AND MAIN RESULTS

During the study period, 112 of 5,148 patients (2.2%) underwent tracheostomy after cardiac surgery. Early tracheostomy was performed in 62 patients, and 50 patients underwent late tracheostomy. Both groups of patients were similar in terms of preoperative and intraoperative characteristics, perioperative risk, and postoperative complications. Patients in the early group had a significantly shorter ventilation time (31.3 ± 23.6 v 39.4 ± 22.4 d; p = 0.034), shorter ICU stay (37.7 ± 21.7 v 46.4 ± 25 d; p = 0.025), and a shorter hospital stay (53.4 ± 29.3 v 66.8 ± 38.5 d; p = 0.020). There were no intergroup differences in weaning rates and in-hospital, 3-month, and 1- and 2-year mortality.

CONCLUSIONS

In this study, early tracheostomy after cardiac surgery in patients requiring prolonged mechanical ventilation was associated with a shorter ventilation time and ICU and hospital stay, but did not result in a lower in-hospital and long-term mortality rate.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Predictors and impact of massive bleeding in acute type A aortic dissection

Objectives

Bleeding complications associated with acute type A aortic dissection (aTAAD) are a well-known clinical problem. Here, we evaluated predictors of massive bleeding related to aTAAD and associated surgery and assessed the impact of massive bleeding on complications and survival.

Methods

This retrospective study of 256 patients used Blood Conservation Using Antifibrinolytics in a Randomized Trial (BART) criteria to define massive bleeding, which was met by 66 individuals (Group I) who were compared to the remaining patients (Group II). Multivariable logistic regression was used to identify independent predictors of massive bleeding and in-hospital mortality, Kaplan-Meier estimates for analysis of late survival, and Cox regression analysis to evaluate independent predictors of late mortality.

Results

Independent predictors of massive bleeding included symptom duration (odds ratio [OR], 0.974 per hour increment; 95% confidence interval [CI], 0.950-0.999; P  =   0.041) and DeBakey type 1 dissection (OR, 2.652; 95% CI, 1.004-7.008; P  =   0.049). In-hospital mortality was higher in Group I (30.3% vs 8.0%, P  <0.001). Kaplan-Meier estimates of survival indicated poorer survival for Group I at 1, 3 and 5 years (68.8 ± 5.9% vs 92.8 ± 1.9%; 65.2 ± 6.2% vs 85.3 ± 2.7%; 53.9 ± 6.9% vs 82.1 ± 3.3 %, respectively; log rank P  <   0.001). Re-exploration for bleeding was an independent predictor of in-hospital (OR, 3.109; 95% CI, 1.044-9.256; P  =   0.042) and late mortalities (hazard ratio, 3.039; 95% CI, 1.605-5.757; P  =   0.001).

Conclusions

Massive bleeding in patients with aTAAD is prompted by shorter symptom duration and longer extent of dissection and has deleterious effects on outcomes of postoperative complications as well as in-hospital and late mortalities.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Prediction of Transfusions After Isolated Coronary Artery Bypass Grafting Surgical Procedures

BACKGROUND

Although blood transfusions are common and have been associated with adverse sequelae after cardiac surgical procedures, few contemporaneous models exist to support clinical decision making. This study developed a preoperative clinical decision support tool to predict perioperative red blood cell transfusions in the setting of isolated coronary artery bypass grafting.

METHODS

We performed a multicenter, observational study of 20,377 patients undergoing isolated coronary artery bypass grafting among patients at 39 hospitals participating in the Michigan Society of Thoracic and Cardiovascular Surgeons Quality Collaborative's PERFusion measures and outcomes (PERForm) registry between 2011 and 2015. Candidates' preoperative risk factors were identified based on previous work and clinical input. The study population was randomly divided into a 70% development sample and a 30% validation sample. A generalized linear mixed-effect model was developed to predict perioperative red blood cell transfusion. The model's performance was assessed for calibration and discrimination. Sensitivity analysis was performed to assess the robustness of the model in different clinical subgroups.

RESULTS

Transfusions occurred in 36.8% of patients. The final regression model included 16 preoperative variables. The correlation between the observed and expected transfusions was 1.0. The risk prediction model discriminated well (receiver operator characteristic [ROC]_development, 0.81; ROC_validation, 0.82) and had satisfactory calibration (correlation between observed and expected rates was r = 1.00). The model performance was confirmed across medical centers and clinical subgroups.

CONCLUSIONS

Our risk prediction model uses 16 readily obtainable preoperative variables. This model, which provides a patient-specific estimate of the need for transfusion, offers clinicians a guide for decision making and evaluating the effectiveness of blood management strategies.

Developing a Blood Conservation Program in Cardiac Surgery

The beneficial effects of blood transfusions have been described and widely accepted. Multiple factors, including shortages, costs, infectious risks, immunologic risks, and the risk/benefit ratio to the patient, have made the medical community reassess the guidelines for transfusion. Cardiac surgery presents a unique subset of patients, because intervention at multiple stages in the care of these patients is possible to decrease the need for transfusion. An algorithm for a cardiac surgery program was developed and a reassessment performed. Once it was seen that no detrimental effect on patient care occurred, the program was expanded, was enhanced, and subsequently has been offered to the rest of the health care system. This program has resulted in a decrease in cost while maintaining patient outcomes. The success of the program is believed to be a result of the multidisciplinary approach taken, with a commitment from all members of the blood reduction team being the key component of this success.

Preoperative hemoglobin level: the best predictor of transfusion of packed red cells

Blood transfusions could have serious consequences for patients. A reduction in the transfusion rate could be accomplished by an optimized blood management. Clear guidelines and awareness among all employees at a single institution have resulted in a reduction in transfusion rates in recent years. Identification of the group of patients who still received a blood transfusion in recent years could result in a further reduction. This study enrolled 4022 patients undergoing cardiothoracic surgery between 2008 and 2013. Patients were divided into three groups: “no blood transfusion”, “transfusion of packed red cells only” and “any other combinations of blood transfusion”. In total, 16 variables were tested for their association with the administration of homologous blood. The variables associated with blood transfusion were included in a stepwise multinomial logistic regression analysis to find the variables with the strongest association.

For the transfusion of packed red cells only and any other combinations of blood transfusion, the following predictors are found: gender, age, weight, type of surgery, reoperation, unstable angina pectoris, endocarditis, recent myocardial infarction, preoperative creatinine level, preoperative hemoglobin level and preoperative platelet count. The best predictor for the transfusion of packed red cells is preoperative hemoglobin level (4.1 to 7.8 mmol/l). For other blood products, the strongest association was found with type of surgery (aortic surgery, ventricular septal rupture and intracardiac tumour).

Does incorporation of thromboelastography improve bleeding prediction following adult cardiac surgery?

Cardiopulmonary bypass (CPB) coagulopathy increases utilization of allogenic blood/blood products, which can negatively affect patient outcomes. Thromboelastography (TEG) is a point-of-care measurement of clot formation and fibrinolysis. We investigated whether the addition of TEG parameters to a clinically based bleeding model would improve the predictability of postoperative bleeding. A total of 439 patients’ charts were retrospectively investigated for 8-h chest tube output (CTO) postoperatively. For model 1, the variables recorded were patient age, gender, body surface area, clopidogrel use, CPB time, first post-CPB fibrinogen serum level, first post-CPB platelet count, first post-CPB international normalized ratio, the total amount of intraoperative cell saver blood transfused, and postoperative first ICU hematocrit level. Model 2 had the model 1 variables, TEG angle, and maximum amplitude. The outcome was defined as 0–8-h CTO. The predictor variables were placed into a forward stepwise regression model for continuous outcomes. Analysis of variance with adjusted R² was used to assess the goodness-of-fit of both predictive models. The predictive accuracy of the model was examined using CTO as a dichotomous variable (75th percentile, 480 ml) and receiver operating characteristic curves for both models. Advanced age, male gender, preoperative clopidogrel use for 5 days or less, greater cell saver blood utilization, and lower postoperative hematocrit levels were associated with increased 8-h CTO (P < 0.05). Adding TEG angle and maximum amplitude to model 1 did not improve CTO predictability. When TEG angle and maximum amplitude were added as predictor factors, the predictability of the bleeding model did not improve.

Relationship between Nadir Hematocrit during Cardiopulmonary Bypass and Postoperative Hyperglycemia in Nondiabetic Patients

<p><b>Background:</b> Hyperglycemia is common after cardiac surgery in both diabetic and nondiabetic patients and is associated with increased morbidity and mortality. Association between nadir hematocrit levels on cardiopulmonary bypass (CPB) and postoperative hyperglycemia is not clear. This study was carried out to determine the relationship between nadir hematocrit during CPB and postoperative hyperglycemia in nondiabetic patients.</p><p><b>Methods:</b> Records of 200 nondiabetic patients undergoing coronary artery bypass grafting operation were retrospectively reviewed. In the first analysis, patients were divided into two subgroups according to the presence or absence of hyperglycemia. Further analysis was made after dividing the patients into 3 subgroups according to nadir hematocrit levels on CPB (less than 20%; 20% to 25%; greater than or equal to 25%).</p><p><b>Results:</b> Compared to patients without hyperglycemia, patients with postoperative hyperglycemia had significantly lower preoperative hematocrit levels (p = 0.004) and were associated with lower nadir hematocrit levels during CPB (p= 0.002). Peak intensive care unit blood glucose levels and number of blood transfusions were significantly higher in patients with nadir hematocrit levels less than 20. (p<0.001 and p<0.001 respectively). Logistic regression analysis demonstrated that nadir hematocrit levels less than 20% (OR 2.9, p=0.009) and allogenic blood transfusion (OR 1.5, p=0.003) were independently associated with postoperative hyperglycemia.</p><p><b>Conclusions:</b> Nadir hematocrit levels on CPB less than 20% and allogenic blood transfusions were independently associated with postoperative hyperglycemia in nondiabetic patients. Patients with a nadir hematocrit levels less than 20 % during CPB should be closely monitored for hyperglycemia in the perioperative period.</p>

Blood transfusions in cardiac surgery: indications, risks, and conservation strategies

Although red blood cell (RBC) transfusions are frequently used in cardiac operations, an increasing amount of data has demonstrated deleterious consequences. Consequently, the appropriate use of this limited resource is unclear. In this review, we discuss the relationship between anemia and the outcomes of cardiac surgical procedures, the risks associated with RBC transfusion, and the impact of blood transfusions on mortality and morbidity after cardiac operations. The review concludes with a discussion of randomized trials comparing restrictive versus liberal transfusion strategies and a consideration of blood conservation techniques.

Blood transfusion and infection after cardiac surgery

Cardiac surgery is the largest consumer of blood products in medicine; although believed life saving, transfusion carries substantial adverse risks. This study characterizes the relationship between transfusion and risk of major infection after cardiac surgery. In all, 5,158 adults were prospectively enrolled to assess infections after cardiac surgery. The most common procedures were isolated coronary artery bypass graft surgery (31%) and isolated valve surgery (30%); 19% were reoperations. Infections were adjudicated by independent infectious disease experts. Multivariable Cox modeling was used to assess the independent effect of blood and platelet transfusions on major infections within 60 ± 5 days of surgery. Red blood cells (RBC) and platelets were transfused in 48% and 31% of patients, respectively. Each RBC unit transfused was associated with a 29% increase in crude risk of major infection (p < 0.001). Among RBC recipients, the most common infections were pneumonia (3.6%) and bloodstream infections (2%). Risk factors for infection included postoperative RBC units transfused, longer duration of surgery, and transplant or ventricular assist device implantation, in addition to chronic obstructive pulmonary disease, heart failure, and elevated preoperative creatinine. Platelet transfusion decreased the risk of infection (p = 0.02). Greater attention to management practices that limit RBC use, including cell salvage, small priming volumes, vacuum-assisted venous return with rapid autologous priming, and ultrafiltration, and preoperative and intraoperative measures to elevate hematocrit could potentially reduce occurrence of major postoperative infections.

Outcomes in cardiac surgery in 500 consecutive Jehovah's Witness patients: 21 year experience

BACKGROUND

Refusal of heterogenic blood products can be for religious reasons as in Jehovah's Witnesses or otherwise or as requested by an increasing number of patients. Furthermore blood reserves are under continuous demand with increasing costs. Therefore, transfusion avoidance strategies are desirable. We describe a historic comparison and current results of blood saving protocols in Jehovah's Witnesses patients.

METHODS

Data on 250 Jehovah's Witness patients operated upon between 1991 and 2003 (group A) were reviewed and compared with a second population of 250 patients treated from 2003 to 2012 (group B).

RESULTS

In group A, mean age was 51 years of age compared to 68 years in group B. An iterative procedure was performed in 13% of patients in group B. Thirty days mortality was 3% in group A and 1% in group B despite greater operative risk factors, with more redo, and lower ejection fraction in group B. Several factors contributed to the low morbidity-mortality in group B, namely: preoperative erythropoietin to attain a minimal hemoglobin value of 14 g/dl, warm blood cardioplegia, the implementation of the Cornell University protocol and fast track extubation.

CONCLUSIONS

Cardiac surgery without transfusion in high-risk patients such as Jehovah Witnesses can be carried out with results equivalent to those of low risk patients. Recent advances in surgical techniques and blood conservation protocols are main contributing factors.

Drug, Devices, Technologies, and Techniques for Blood Management in Minimally Invasive and Conventional Cardiothoracic Surgery a Consensus Statement from the International Society for Minimally Invasive Cardiothoracic Surgery (ISMICS) 2011

Objective

The objectives of this consensus conference were to evaluate the evidence for the efficacy and safety of perioperative drugs, technologies, and techniques in reducing allogeneic blood transfusion for adults undergoing cardiac surgery and to develop evidence-based recommendations for comprehensive perioperative blood management in cardiac surgery, with emphasis on minimally invasive cardiac surgery.

Methods

The consensus panel short-listed the potential topics for review from a comprehensive list of potential drugs, devices, technologies, and techniques. The process of short-listing was based on the need to prioritize and focus on the areas of highest importance to surgeons, anesthesiologists, perfusionists, hematologists, and allied health care involved in the management of patients who undergo cardiac surgery whether through the conventional or minimally invasive approach. MEDLINE, Cochrane Library, and Embase databases were searched from their date of inception to May 2011, and supplemental hand searches were also performed. Detailed methodology and search strategies are outlined in each of the subsequently published systematic reviews. In general, all relevant synonyms for drugs (antifibrinolytic, aprotinin, ∊-aminocaproic acid, tranexamic acid [TA], desmopressin, anticoagulants, heparin, antiplatelets, anti-Xa agents, adenosine diphosphate inhibitors, acetylsalicylic acid [ASA], factor VIIa [FVIIa]), technologies (cell salvage, miniaturized cardiopulmonary bypass (CPB) circuits, biocompatible circuits, ultrafiltration), and techniques (transfusion thresholds, minimally invasive cardiac or aortic surgery) were searched and combined with terms for blood, red blood cells, fresh-frozen plasma, platelets, transfusion, and allogeneic exposure. The American Heart Association/American College of Cardiology system was used to label the level of evidence and class of each recommendation.

Results and Recommendations

Database search identified more than 6900 articles, with 4423 full-text randomized controlled trials assessed for eligibility, and the final 125 systematic reviews and meta-analyses were used in the consensus conference. The results of the consensus conference, including the evidence-based statements and the recommendations, are outlined in the text, with references given for the relevant evidence that formed the basis for the statements and recommendations.

Focus on Thrombin: Alternative Anticoagulants

Unfractionated heparin and protamine have been integral to cardiopulmonary bypass since cardiac surgery was first undertaken. These drugs are inexpensive and well understood but are contraindicated in some individuals, and resistance to heparin can be problematic in others. The interplay between the endothelium, anticoagulants, the coagulation cascade, and the inflammatory response that characterizes cardiac surgery may contribute to some of the complications associated with cardiopulmonary bypass. Various alternative drugs and strategies have been used to manage patients unsuitable for heparin or protamine, but each has its own disadvantages. At present, direct thrombin inhibitors may offer the best available alternative to heparin in cardiac surgery, particularly the short-acting bivalirudin, but this class of anticoagulants is relatively expensive and has no reversal agent. Balanced anticoagulation using combinations of drugs that act at different stages in the coagulation system may improve the management of coagulation in cardiac surgery, but careful investigation of this concept is needed.

Meta-analysis comparing the effectiveness and adverse outcomes of antifibrinolytic agents in cardiac surgery

BACKGROUND

Since the 1980s, antifibrinolytic therapies have assisted surgical teams in reducing the amount of blood loss. To date, however, serious questions remain regarding the safety and effectiveness of these agents.

METHODS AND RESULTS

We conducted a meta-analysis to compare aprotinin, epsilon-aminocaproic acid, and tranexamic acid with placebo and head to head on 8 clinical outcomes from 138 trials. Published randomized controlled trial data were collected from OVID/PubMed. Outcomes included total blood loss, transfusion of packed red blood cells, reexploration, mortality, stroke, myocardial infarction, dialysis-dependent renal failure, and renal dysfunction (0.5-mg/dL increase in creatinine from baseline). All agents were effective in significantly reducing blood loss by 226 to 348 mL and the proportion of patients transfused with packed red blood cells over placebo. Only high-dose aprotinin reduced the rate of reexploration (relative risk, 0.49; 95% CI, 0.33 to 0.73). There were no significant risks or benefits for any agent for mortality, stroke, myocardial infarction, or renal failure. However, high-dose aprotinin significantly increased the risk of renal dysfunction (relative risk, 1.47; 95% CI, 1.12 to 1.94), 12.9% versus 8.4%. Compared head to head, high-dose aprotinin demonstrated significant reduction in total blood loss over epsilon-aminocaproic acid (-184 mL; 95% CI, -256 to -112) and tranexamic acid (-195 mL; 95% CI, -286 to -105). There were no significant differences among any agent when compared head to head on other outcomes.

CONCLUSIONS

All antifibrinolytic agents were effective in reducing blood loss and transfusion. There were no significant risks or benefits for mortality, stroke, myocardial infarction, or renal failure. However, high-dose aprotinin was associated with a statistically significant increased risk of renal dysfunction.

The effects of a treatment protocol for cardiac surgical patients with excessive blood loss on clinical outcomes

BACKGROUND AND OBJECTIVES

Excessive blood loss (EBL) is a common complication of cardiac surgery that is associated with adverse events. The objective of this before/after study was to determine whether the implementation of a protocol for management of cardiac surgical patients with EBL was associated with improved clinical outcomes.

MATERIALS AND METHODS

In November 2002, a protocol for prompt identification and aggressive management of cardiac surgical patients with EBL was implemented at our institution. The independent relationship between protocol implementation and adverse outcomes was measured by comparing the outcomes of patients who received > or = 4 RBC (red blood cell) units within 1 day of surgery and were operated on before protocol implementation (2000-02) with those operated on after protocol implementation (2003-05), using multivariable logistic regression analysis to control for the effects of confounders. The primary outcome was a composite of adverse events that included death, renal failure, stroke, and sepsis. Bootstrapping was used to confirm the validity of the results.

RESULTS

Of the 11,314 patients who underwent surgery during the study period, 1875 (16.6%) received > or = 4 RBC units within 1 day of surgery, with 958 and 917 in the pre- and postprotocol periods, respectively. The composite adverse outcome occurred in 164 (17.1%) patients in the preprotocol period and 115 (12.5%) patients in the postprotocol period (P = 0.005). Protocol implementation was independently associated with reduced odds of the composite adverse outcome (odds ratio 0.67; 95% confidence interval 0.50, 0.91; P = 0.01). This estimate was stable in bootstrap sampling.

CONCLUSION

Implementation of a protocol to manage EBL in cardiac surgery was independently associated with improved outcomes.