Review of the clinical practice literature on patient characteristics associated with perioperative allogeneic red blood cell transfusion

Perioperative Transfusion Practices in Adults Having Noncardiac Surgery

Surgical patients are often transfused to manage bleeding and anemia. Best practices for red blood cell (RBC) transfusion administration in patient having noncardiac surgery remains controversial and a robust evaluation and description of perioperative transfusion practices is lacking. We characterized perioperative hemoglobin concentrations and transfusion practices from the prospective VISION cohort which included 39,222 patients aged ≥45 years who had inpatient noncardiac surgery. Variations in transfusion practices were analyzed using hierarchical mixed models, and associations with mortality and complications were evaluated using a nested frailty survival model. Within the cohort, 16.1% (n = 6296) were given perioperative RBC transfusions, with the fraction declining from 20% to 13% over the 6-year study period. The proportion of patients transfused varied by surgery type from 6.4% for low-risk operations (i.e., minor surgery) to 31.5% for orthopedic surgeries. Variations were largely associated with patient hemoglobin concentrations, but also with center (range: 3.7%-27.3%) and country (0.4%-25.3%). Even after adjusting for baseline hemoglobin, comorbidities and type of surgery, both center and country were significant sources of variation in transfusion practices. Among transfused participants, 60.4% (n = 3728/6170) had at least 1 hemoglobin concentration ≤80g/L and 86.0% (n = 5305/6170) had at least 1 hemoglobin concentration ≤90g/L, suggesting that relatively restrictive transfusion strategies were used in most. The proportion of patients receiving at least 1 RBC transfusion declined from 20% to 13% over 6 years. However, there was considerable unexplained variation in transfusion practices.

Iron deficiency anemia is associated with increased medical and implant-related complications and length of stay for patients undergoing total shoulder arthroplasty

BACKGROUND

Iron deficiency anemia (IDA) is associated with decreased bone mineral density and osteoporosis; however, studies investigating the effects of IDA in patients undergoing primary total shoulder arthroplasty (TSA) have not been well studied. The purpose of this study is to utilize a nationwide administrative claims database to investigate whether patients with diagnosed IDA undergoing primary TSA have higher rates of 1) in-hospital length of stay (LOS); 2) medical complications; and 3) implant-related complications.

METHODS

A retrospective review from 2005 to 2014 was conducted using the Medicare Standard Analytical Files. Patients with IDA undergoing primary TSA were identified and matched to controls without IDA, in a 1:5 ratio by age, sex, and medical comorbidities. Outcomes analyzed included in-hospital LOS and 90-day medical and implant-related complications. Mann-Whitney U tests compared in-hospital LOS, and multivariate logistic regression was used to calculate odds ratios (ORs) on the effects of IDA on postoperative complications after adjusting for age, sex, and Elixhauser Comorbidity Index.

RESULTS

A total of 17,689 patients with IDA and 88,445 without IDA participated in the matched-cohort analysis, with no differences in age, gender, and comorbidities (P = .99). IDA patients were found to have significantly longer in-hospital LOS (3-days vs. 2-days, P < .0001). IDA patients were also found to have significantly higher odds of 90-day implant-related complications (OR: 1.65, P < .0001), such as periprosthetic joint infections (OR: 1.80, P < .0001) and 90-day medical complications (OR: 2.87, P < .0001), including blood transfusions (OR: 10.37, P < .0001).

CONCLUSION

Patients with IDA undergoing primary TSA have significantly longer in-hospital LOS, and medical and implant-related complications. Patients were 10 times more likely to undergo a blood transfusion and 2 times more likely to have a periprosthetic fracture.

Intraoperative transfusion practices and perioperative outcome in the European elderly: A secondary analysis of the observational ETPOS study

The demographic development suggests a dramatic growth in the number of elderly patients undergoing surgery in Europe. Most red blood cell transfusions (RBCT) are administered to older people, but little is known about perioperative transfusion practices in this population. In this secondary analysis of the prospective observational multicentre European Transfusion Practice and Outcome Study (ETPOS), we specifically evaluated intraoperative transfusion practices and the related outcomes of 3149 patients aged 65 years and older. Enrolled patients underwent elective surgery in 123 European hospitals, received at least one RBCT intraoperatively and were followed up for 30 days maximum. The mean haemoglobin value at the beginning of surgery was 108 (21) g/l, 84 (15) g/l before transfusion and 101 (16) g/l at the end of surgery. A median of 2 [1-2] units of RBCT were administered. Mostly, more than one transfusion trigger was present, with physiological triggers being preeminent. We revealed a descriptive association between each intraoperatively administered RBCT and mortality and discharge respectively, within the first 10 postoperative days but not thereafter. In our unadjusted model the hazard ratio (HR) for mortality was 1.11 (95% CI: 1.08-1.15) and the HR for discharge was 0.78 (95% CI: 0.74-0.83). After adjustment for several variables, such as age, preoperative haemoglobin and blood loss, the HR for mortality was 1.10 (95% CI: 1.05-1.15) and HR for discharge was 0.82 (95% CI: 0.78-0.87). Pre-operative anaemia in European elderly surgical patients is undertreated. Various triggers seem to support the decision for RBCT. A closer monitoring of elderly patients receiving intraoperative RBCT for the first 10 postoperative days might be justifiable. Further research on the causal relationship between RBCT and outcomes and on optimal transfusion strategies in the elderly population is warranted. A thorough analysis of different time periods within the first 30 postoperative days is recommended.

Models to predict the probability for intraoperative RBC transfusion during lumbar spinal stenosis and femoral fracture surgeries in aged patients

OBJECTIVE

The goal of this study was to predict the probability of transfusion of red blood cells and the volume of blood consumption based on the clinical characteristics of patients before surgery.

METHODS

The medical records of 565 patients over 65 years old who underwent posterior lumbar surgery and 586 patients over 65 years old receiving femoral fracture surgery were reviewed. The clinical characteristics of the patients were subjected to multivariate regression analysis. The scores of these factors' influences on intraoperative red blood cells infusion were based on the odds ratio of each multivariate risk factor. Non-linear regression was performed to predict the probability of intraoperative blood transfusion and the volume of blood used for patients with different scores.

RESULTS

The factors that significantly influenced blood use during lumbar spinal stenosis and femoral fracture surgery in aged patients(P < 0.05) included age, body mass index, abnormal coagulation function, preoperative hemoglobin, administration of antithrombotic drugs, multisegmental lesions of the lumbar spine, femoral shaft fracture, secondary lumbar surgery and the time from fracture to surgery exceeding 48 h. According to our risk scoring system, patients of posterior lumbar surgery scored 0-10 and patients of femoral fracture had a score of 0-12. More than 50 % of patients receiving an intraoperative red blood cells transfusion during surgery scored>1.

CONCLUSION

The scoring system can be used as a predictive model for the probability of red blood cells transfusion and the blood volume in aged patients undergoing lumbar spinal stenosis and femoral fracture surgeries.

Preoperative risk factors for postoperative pneumonia following primary Total Hip and Knee Arthroplasty

BACKGROUND

The purpose of this study is to evaluate risk factors for pneumonia following THA and TKA.

METHODS

Patients were identified from the American College of Surgeons National Quality Improvement Database (NSQIP) who experienced postoperative pneumonia after undergoing primary THA and TKA.

RESULTS

Many characteristics including old age, anemia, diabetes, cardiac comorbidities, dialysis, and smoking were independent risk factors for postoperative pneumonia after THA or TKA.

CONCLUSION

This analysis offers new evidence on risk factors associated with the development of pneumonia after THA and TKA. These risk factors can help guide clinicians in preventing postoperative pneumonia after THA and TKA.

Mid-term outcomes of rapid deployment aortic prostheses in patients with small aortic annulus

OBJECTIVES

The Edwards Intuity valve is a rapid deployment aortic prosthesis that favours less invasive approaches. However, evidence about the clinical behaviour of their smaller sizes is scarce. Herein, we studied haemodynamic behaviours and clinical outcomes of small Intuity prostheses (19-21 mm) in comparison to larger Intuity prostheses (>21 mm).

METHODS

This is an observational study including patients implanted with an Edwards Intuity rapid deployment aortic prosthesis. Patients with prosthesis sizes 19-21 and >21 mm were included. Baseline and perioperative variables, as well as adverse events during the follow-up were recorded and compared between groups.

RESULTS

A total of 122 patients (37% female, mean age 75 ± 4.5 years) were included, of whom 54 (45%) were implanted with a small prosthesis and 68 (55%) with a prosthesis >21 mm. There were no significant differences between patients with small Intuity prostheses and patients with larger prostheses regarding in-hospital mortality (2% vs 4%, P = 0.43) or mortality during the follow-up (3.41 vs 2.45 per 100 patients-years; P = 0.58). Survival in the small Intuity valve group was 95% at 1 year and 83% at 6 years, whereas in the larger Intuity valve group was 96% at 1 year and 78% at 6 years. The presence of a small prosthesis did not influence mid-term survival (log-rank P-value = 0.62).

CONCLUSIONS

This study showed good clinical performance of Intuity aortic prostheses with appropriate mid-term survival in patients with the small aortic annulus. Thus, the Edwards Intuity rapid deployment aortic prosthesis may be considered as a potential option in patients with the small aortic annulus.

Machine learning models to predict red blood cell transfusion in patients undergoing mitral valve surgery

Background

Red blood cell (RBC) transfusion therapy has been widely used in surgery, and has yielded excellent treatment outcomes. However, in some instances, the demand for RBC transfusion is assessed by doctors based on their experience. In this study, we use machine learning models to predict the need for RBC transfusion during mitral valve surgery to guide the surgeon's assessment of the patient's need for intraoperative blood transfusion.

Methods

We retrospectively reviewed 698 cases of isolated mitral valve surgery with and without combined tricuspid valve operation. Seventy percent of the database was used as the training set and the remainder as the testing set for 13 machine learning algorithms to build a model to predict the need for intraoperative RBC transfusion. According to the characteristic value of model mining, we analyzed the risk-related factors to determine the main effects of variables influencing the outcome.

Results

A total of 166 patients of the cases considered had undergone intraoperative RBC transfusion (24.52%). Of the 13 machine learning algorithms, CatBoost delivered the best performance, with an AUC of 0.888 (95% CI: 0.845-0.909) in testing set. Further analysis using the CatBoost model revealed that hematocrit (<37.81%), age (>64 y), body weight (<59.92 kg), body mass index (BMI) (<22.56 kg/m²), hemoglobin (<122.6 g/L), type of surgery (median thoracotomy surgery), height (<160.61 cm), platelet (>194.12×10⁹/L), RBC (<4.08×10¹²/L), and gender (female) were the main risk-related factors for RBC transfusion. A total of 204 patients were tested, 177 of whom were predicted accurately (86.8%).

Conclusions

Machine learning models can be used to accurately predict the outcomes of RBC transfusion, and should be used to guide surgeons in clinical practice.

Unnecessary Blood Transfusion Prolongs Length of Hospital Stay of Patients Who Undergo Free Fibular Flap Reconstruction of Mandibulofacial Defects: A Propensity Score-Matched Study

PURPOSE

Blood transfusion is usually a common clinical practice in flap transfer surgery because of its invasive hemorrhagic nature. Although intraoperative restrictive transfusion policy was suggested in vascularized fibular flap reconstruction, its clinical evidence was still insufficient. Therefore, our study aimed to investigate the influence of intraoperative blood transfusion on length of stay (LOS) after vascularized fibular flap reconstruction.

PATIENTS AND METHODS

Patients who underwent vascularized fibular flap reconstruction of mandibulofacial defects between 2012 and 2018 were reviewed. Univariate and multivariate analyses were performed to identify factors that influenced LOS. The identified factors and other perioperative factors that may influence transfusion decision were included in propensity score matching to explore the independent impact of intraoperative blood transfusion on LOS.

RESULTS

About 375 patients were included, and the median LOS was 14.00 (12.00, 19.00) days in our study. Multivariate analysis suggested that duration of surgery, fluid infusion speed for more than 24 hours on operative day, intraoperative blood transfusion, and postoperative complication were associated with prolonged LOS (P < .05). Propensity score matching was performed, and the difference of LOS between the matched transfused and nontransfused group was statistically significant (15.00 [12.75, 20.00] vs 14.00 [11.75, 16.25]; P < .001). The comparison between the matched and unmatched transfused patients indicated that the former has less radiotherapy history, blood loss, and higher preoperative hemoglobin (P ≤ .001).

CONCLUSIONS

Intraoperative blood transfusion is independently associated with prolonged LOS in patients without preoperative anemia, radiotherapy history, or intraoperative massive hemorrhage who undergo vascularized fibular flap reconstruction. Efforts should be made to avoid unnecessary intraoperative blood transfusion, and our results support consideration of a restrictive transfusion policy in these patients.

Anaemia in patients undergoing major bowel surgery - Prevalence and current practice: A public and private institution experience

AIM

The study aimed to compare the frequency and alignment of preoperative anaemia screening and treatment with Australian guidelines in elective bowel surgery and determine the impact on clinical outcomes.

METHODS

We performed a retrospective observational study, with an audit of 559 adult patients who underwent major elective bowel surgery in an Australian metropolitan hospital, January 2016-December 2018. Outcome measures included rate of anaemia, guideline compliance, hospital length of stay, and transfusion rate.

RESULTS

Preoperative anaemia assessment occurred in 82.6% of patients. However, only 5.2% received recommended biochemical tests at least one week before surgery. Only 25.2% of anaemic patients received preoperative treatment; they experienced a longer hospital length of stay (9.93 days versus 7.88 days, p < 0.001) and an increased rate of transfusion (OR: 3.186, p < 0.05).

CONCLUSION

The gaps between current preoperative anaemia screening, management and national guidelines may place patients at higher risk of poor surgical outcome.

Restrictive allogeneic blood transfusion strategy in patients with extremity bone sarcomas

Allogeneic blood transfusions (ABTs) are common in patients with cancer. The present study investigated the safety of a restrictive ABT strategy in patients with extremity sarcomas.Patients who underwent operations for extremity bone sarcomas between May 2008 and November 2018 were retrospectively reviewed. Clinical outcomes based on hemoglobin concentrations, postoperative infections, and hospital stay were compared between 20 patients who received liberal ABT (control group) and 19 patients who received restrictive ABT (restrictive group). The rates of distant metastasis and death were compared between the groups.The mean number of ABTs was 3.6 ± 3.8 units in the control group and 0.33 ± 0.74 units in the restrictive group (P < .001). Only 3 of 19 patients received transfusions (2 red cell packs each). The hemoglobin levels tended to fall during the first 3 postoperative days but seemed to stabilize within the first postoperative week in both groups. Postoperative surgical site infections only occurred in the patients who received ABTs regardless of the group. The rates of distant metastasis and death were higher in the control group than in the restrictive group (25.0% vs 15.7% and 10.0% vs 0%, respectively), but the differences were not significant.A restrictive ABT strategy may be safely performed in patients with extremity bone sarcomas depending on the intraoperative status and specific characteristics of each patient.

Predictors and outcomes of perioperative blood transfusions in classic bladder exstrophy repair: A single institution study

BACKGROUND

Primary bladder closure of classic bladder exstrophy (CBE) is a major operation that occasionally requires intraoperative or postoperative (within 72 h) blood transfusions.

OBJECTIVE

This study reported perioperative transfusion rates, risk factors for transfusion, and outcomes from a high-volume exstrophy center in primary bladder closure of CBE patients.

STUDY DESIGN

A prospectively maintained, institutional exstrophy-epispadias complex database of 1305 patients was reviewed for primary CBE closures performed at the authors' institution (Johns Hopkins Hospital) between 1993 and 2017. Patient and surgical factors were analyzed to determine transfusion rates, risk factors for transfusions, and outcomes. Patients were subdivided into two groups based upon the time of closure: neonatal and delayed closure.

RESULTS

A total of 116 patients had a primary bladder closure during 1993-2017. Seventy-three patients were closed in the neonatal period, and 43 were delayed closures. In total, 64 (55%) patients received perioperative transfusions. No transfusion reactions were observed. Twenty-five transfusions were in the neonatal closure group, yielding a transfusion rate of 34%. In comparison, 39 patients were transfused in the delayed closure group, giving a transfusion rate of 91%. Pelvic osteotomy, delayed bladder closure, higher estimated blood loss (EBL), larger pubic diastasis, and longer operative time were all associated with blood transfusion. In multivariable logistic regression, pelvic osteotomy (OR 5.4; 95% CI 1.3-22.8; P < 0.001), higher EBL-to-weight ratio (OR 1.3; 95% CI 1.1-1.6; P = 0.029), and more recent years of primary closure (OR 1.1; 95% CI 1.0-1.2; P = 0.018) remained independent predictors of receiving a transfusion (Summary Table). No adverse transfusion reactions or complications were observed.

DISCUSSION

This was the first study from a single high-volume exstrophy center to explore factors that contribute to perioperative blood transfusions. Pelvic osteotomy as a risk factor was unsurprising, as the osteotomy may bleed both during and immediately after closure. However, it is important to use osteotomy for successful closure, despite the increased transfusion risk. The risks accompanying contemporary transfusions are minimal and osteotomies are imperative for successful bladder closure.

CONCLUSIONS

More than half of CBE patients undergoing primary closure at a single institution received perioperative blood transfusions. While there was an association between transfusions and osteotomy, delayed primary closure, larger diastasis, increased operative time, and increased length of stay, only the use of pelvic osteotomy, higher EBL-to-weight ratio, and recent year of closure independently increased the odds of receiving a transfusion on multivariate analysis.

Long-term audit of the use of fresh frozen plasma in a university hospital

OBJECTIVES

There is universal concern about the inappropriate use of fresh frozen plasma (FFP). This study aimed to determine the extent of the inappropriate use of FFP at a university hospital in KSA.

METHODS

Medical records on the annual use of FFP were analysed from 1986 to 2007. Then, the results of the coagulation screening tests were extracted from the medical records of 531 consecutive patients in various departments of the hospital.

RESULTS

As many as 68,480 FFP units were used during the 22 year study period. Consumption increased and then plateaued in 1995, but dropped dramatically by 30.9% and reached its lowest level in 2000. There was also a concomitant and overlapping drop in both FFP usage and the hospital mortality rate per patient admission. One-thousand-six-hundred-twenty FFP units were issued for 531 patients. Coagulation testing, before and after infusion, was adopted in almost all patients in the Department of Obstetrics and Gynaecology, in 90% of patients in the Department of Surgery and in approximately 70% of patients in other departments.

CONCLUSIONS

Significant inappropriate use of FFP at our institute has been made evident by examining the remarkable drop in use following the universal "HIV scare" of the early 1990s. The resulting drop in the hospital mortality rate, accompanying the simultaneous drop in FFP use, reflects the benefits of resorting to the use of less blood therapy. Coagulation testing was used to a satisfactory extent. Transfusion audits and educational programs could result a better use of FFP.

Hospital variation in allogeneic transfusion and extended length of stay in primary elective hip and knee arthroplasty: a cross-sectional study

OBJECTIVES

Outcomes in total hip and knee arthroplasty (THA and TKA), such as allogeneic transfusions or extended length of stay (LoS), can be used to compare the performance of hospitals. However, there is much variation in these outcomes. This study aims to rank hospitals and to assess hospital differences of two outcomes in THA and TKA: allogeneic transfusions and extended LoS, and to additionally identify factors associated with these differences.

DESIGN

Cross-sectional medical record review study.

SETTING

Data were gathered in 23 Dutch hospitals.

PARTICIPANTS

1163 THA and 986 TKA patient admissions.

OUTCOMES

Hospitals were ranked based on their observed/expected (O/E) ratios regarding allogeneic transfusion and extended LoS percentages (extended LoS was defined by postoperative stay >4 days). To assess the reliability of these rankings, we calculated which percentage of the existing variation was based on differences between hospitals as compared with random variation (after adjustment for variation in patient characteristics). Associations between hospital-specific factors and O/E ratios were used to explore potential sources of differences.

RESULTS

The variation in O/E ratios between hospitals ranged from 0 to 4.4 for allogeneic transfusion, and from 0.08 to 2.7 for extended LoS. Variation in transfusion could in 21% be explained by hospital differences in THA and 34% in TKA. For extended LoS this was 71% in THA and 78% in TKA. Better performance (low O/E ratios) in transfusion was associated with more frequent tranexamic acid (TXA) use in TKA (R=-0.43, p=0.04). Better performance in extended LoS was associated with more frequent TXA use in THA (R=-0.45, p=0.03) and TKA (R=-0.65, p<0.001) and local infiltration analgesia (LIA) in TKA (R=-0.60, p=0.002).

CONCLUSIONS

Ranking hospitals based on allogeneic transfusion is unreliable due to small percentages of variation explained by hospital differences. Ranking based on extended LoS is more reliable. Hospitals using TXA and LIA have relatively fewer patients with transfusions and extended LoS.

Are There Modifiable Risk Factors to Improve AKI?

Acute kidney injury (AKI) is a common critical syndrome, with high morbidity and mortality. Patients with AKI typically have an adverse prognosis, from incident chronic kidney disease (CKD), progression to end-stage renal disease (ESRD), subsequent cardiovascular disease, and ultimately death. However, there is currently no effective therapy for AKI. Early detection of risk factors for AKI may offer a good approach to prevention or early intervention. Traditional risk factors include extreme age, many common comorbid diseases, such as preexisting CKD, some specific exposures, such as sepsis, and exposure to some nephrotoxic agents. Recently, several novel risk factors for AKI, such as hyperuricemia, hypoalbuminemia, obesity, anemia, and hyperglycemia, have been identified. The underlying mechanisms between these nontraditional risk factors and AKI and whether their correction can reduce AKI occurrence remain to be clarified. This review describes the current epidemiology of AKI, summarizes its outcome, outlines the traditional risk profile, and finally highlights some recently identified novel risk factors.

Erythropoietin with iron supplementation for preoperative anaemia in non‐cardiac surgery

This is a protocol for a Cochrane Review (Intervention). The objectives are as follows:

We aim to evaluate the efficacy and safety of preoperative erythropoietin (rHuEPO) with supplemental iron (parenteral or oral) in reducing perioperative allogeneic red blood cell transfusions in preoperatively anaemic people undergoing non‐cardiac surgery.

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).

A 23 years audit of packed red blood cell consumption in a university hospital in a developing country

BACKGROUND

There is paucity of information on the blood transfusion practice in developing countries. The current audit aims to find out the long term trend in the consumption of packed red blood cells (PRBCs) in a large Saudi teaching hospital in Riyadh

MATERIALS AND METHODS

We analyzed the annual consumption of PRBCs from 1985 to 2007 in seven major hospital divisions (Medicine, General Surgery, Pediatrics, Obstetrics and Gynecology, Cardiac Surgery, Accident and Emergency and Renal Dialysis Unit) at the 850-bed King Khalid University Hospital (KKUH), Riyadh.

RESULTS

Grand total consumption of PRBCs was 345,642 units. The consumption increased gradually and peaked in the year 1994, dropped to 30.4% 6 years later and then increased gradually thereafter, due to the expansion in the number of patients cared for in the Departments of Medicine, Cardiac Surgery and Accident and Emergency, while in the Department of Pediatrics the drop in consumption continued unabated. In the Renal Dialysis Unit consumption was minimal with the use of erythropoietin therapy. The crossmatch:transfusion ratio uncovered gross over-ordering of PRBCs and wastage of blood bank resources in most hospital divisions most notably in the Department of Obstetrics and Gynecology.

CONCLUSION

The results obtained indicate clearly that there has been overuse of blood products that dropped markedly in years coinciding with the worldwide apprehension about the safety of transfusion therapy particularly HIV transmission. This factor in addition to the current implementation of strict guidelines is gradually improving transfusion practices in our institute.

Risks associated with preoperative anemia and perioperative blood transfusion in open surgery for intracranial aneurysms

OBJECT

Preoperative anemia may be treated with a blood transfusion. Both are associated with adverse outcomes in various surgical procedures, but this has not been clearly elucidated in surgery for cerebral aneurysms. In this study the authors assessed the association of preoperative anemia and perioperative blood transfusion, separately, on 30-day morbidity and mortality in patients undergoing open surgery for ruptured and unruptured intracranial aneurysms.

METHODS

The authors identified 668 cases (including 400 unruptured and 268 unruptured intracranial aneurysms) of open surgery for treatment of intracranial aneurysms in the 2006-2012 National Surgical Quality Improvement Program, a validated and reproducible prospective clinical database. Anemia was defined as a hematocrit level less than 39% in males and less than 36% in females. Perioperative transfusion was defined as at least 1 unit of packed or whole red blood cells given at any point between the start of surgery to 72 hours postoperatively. The authors separately compared surgical outcome between patients with (n = 198) versus without (n = 470) anemia, and those who underwent (n = 78) versus those who did not receive (n = 521) a transfusion, using a 1:1 match on propensity score.

RESULTS

In the matched cohorts, all observed covariates were comparable between anemic (n = 147) versus nonanemic (n = 147) and between transfused (n = 67) versus nontransfused patients (n = 67). Anemia was independently associated with prolonged hospital length of stay (LOS; odds ratio [OR] 2.5, 95% confidence interval [CI] 1.4-4.5), perioperative complications (OR 1.9, 95% CI 1.1-3.1), and return to the operating room (OR 2.1, 95% CI 1.1-4.5). Transfusion was also independently associated with perioperative complications (OR 2.4, 95% CI 1.1-5.3).

CONCLUSIONS

Preoperative anemia and transfusion are each independent risk factors for perioperative complications in patients undergoing surgery for cerebral aneurysms. Perioperative anemia is also associated with prolonged hospital LOS and 30-day return to the operating room.

Modern Patient Blood Management in Arthroplasty

One of the oldest and still commonest procedures in clinical practice, allogeneic blood transfusion (ABT), is not fully supported by available evidence. In the last few decades, increasing concerns about unfavorable outcomes associated with ABT, anticipation of future insufficient blood supply, and awareness of the cost (direct and indirect) of transfusion have led to the promotion of patient blood management (PBM) as a cost-effective strategy, beneficial for patients as well as for society (Shander et al. 2010). PBM programs utilize a series of measures with a proven ability to reduce ABT and to be cost-effective. Despite that the impact of PBM on patient clinical outcomes needs to be fully defined and future studies are needed, PBM should be adopted as a new standard of care.

Prevalence of preoperative anaemia in patients having first-time cardiac surgery and its impact on clinical outcome. A retrospective observational study

The prevalence of anaemia is increasing globally. It has a close association with perioperative blood transfusion which, in turn, results in an increased risk of postoperative complications. Undesirable effects are not only limited to short-term, but also have long-term implications. Despite this, many patients undergo cardiac surgery with undiagnosed and untreated anaemia. We designed a retrospective, observational study to estimate the prevalence of anaemia in patients having cardiac surgery in Auckland District Health Board, blood transfusion rates and associated clinical outcome. Two hundred of seven hundred and twelve (28.1%) patients were anaemic. Red blood cell (RBC) transfusion rates were significantly higher in the anaemic group compared to the non-anaemic group (160 (80%) vs. 192 (38%), p-value <0.0001, RR (CI 95%) 2.133 (1.870-2.433)). Transfusion rates for fresh frozen plasma (FFP), cryoprecipitate and platelets were also higher in the anaemic group. Anaemia was significantly associated with the development of new infection (14 (7%) vs. 15 (2.9%), p-value 0.0193, RR (CI 95%) 2.389 (1.175-4.859)), prolonged ventilation time (47.01 hours vs. 23.59 hours, p-value 0.0076) and prolonged intensive care unit (ICU) stay (80.23 hours vs. 50.27, p-value 0.0011). Preoperative anaemia is highly prevalent and showed a clear link with significantly higher transfusion rates and postoperative morbidity. It is vital that a preoperative management plan for the correction of anaemia should be sought to improve patient safety and outcome.

Impact of preoperative anemia on outcomes in patients undergoing elective cranial surgery

Object

The objective of this study was to assess whether preoperative anemia in patients undergoing elective cranial surgery influences outcomes in the immediate perioperative period (≤ 30 days).

Methods

The National Surgical Quality Improvement Program (NSQIP) was used to identify 6576 patients undergoing elective cranial surgery between 2006 and 2011. Propensity scores were used to match patients with moderate to severe anemia (moderate-severe) or mild anemia with patients without anemia. Logistic regression analysis was used to predict the outcomes of interest. Sensitivity analyses were used to limit the sample to patients without perioperative transfusion as well as those who underwent craniotomy for definitive resection of a malignant brain tumor.

Results

A total of 6576 patients underwent elective cranial surgery, of whom 175 had moderate-severe anemia and 1868 had mild anemia. Patients with moderate-severe (odds ratio 1.8, 95% CI 1.1–2.8) and mild (odds ratio 1.5, 95% CI 1.3–1.7) anemia were more likely to have prolonged length of stay (LOS) in the hospital compared to those with no anemia. Similarly, in patients who underwent craniotomy for a malignant tumor resection (n = 2537), anemia of any severity was associated with prolonged LOS, but not postoperative complications nor death.

Conclusions

Anemia is not associated with an overall increased risk for adverse outcomes in patients undergoing elective cranial surgery. However, patients with anemia are more likely to experience prolonged hospitalization postoperatively, resulting in increased resource utilization.

Variation in the numbers of red blood cell units transfused at different medical institution types from 2006 to 2010 in Korea

Background

This study aimed at assessing the number of red blood cell (RBC) units transfused at different types of medical institution and examining the characteristics of transfusion recipients.

Methods

We calculated and compared the number of transfusion recipients, total RBC units transfused, and RBC units transfused per recipient. Study data were extracted from insurance benefits reimbursement claims for RBC units at the Health Insurance Review & Assessment Service from 2006 to 2010.

Results

Between 2006 and 2010, the number of recipients of RBC units increased from 298,049 to 376,445, the number of RBC units transfused increased from 1,460,799 to 1,841,695, and the number of RBC units transfused per recipient changed from 4.90 to 4.89. The number of recipients aged ≥65 yr increased from 133,833 (44.9%) in 2006 to 196,127 (52.1%) in 2010. The highest number of RBC units was transfused to patients with neoplastic diseases (31.9%) and diseases of the musculoskeletal system and connective tissue (14.4%). More than 80% of the total number of RBC units were transfused at tertiary and general hospitals. However, this composition rate was slightly decreasing, with the composition rate for hospitals increasing from 12.6% to 16.3%.

Conclusions

This study revealed an increase in the number of RBC units transfused over a 5-yr period due to an increase in the number of transfused recipients, especially recipients aged ≥65 yr; moreover, the number of RBC units transfused differed based on medical institution type. These results provide fundamental data on RBC transfusions required for future research.

Preoperative anemia and perioperative outcomes in patients who undergo elective spine surgery

STUDY DESIGN

Analysis of the prospectively collected American College of Surgeons National Surgical Quality Improvement Program database.

OBJECTIVE

To assess whether preoperative anemia predicted adverse, early, perioperative outcomes in patients undergoing elective spine surgery.

SUMMARY OF BACKGROUND DATA

Prior studies have assessed the association of anemia with outcomes in various noncardiac surgical procedures. The association between preoperative anemia and 30-day outcomes for spine surgery is unknown.

METHODS

A total of 24,473 adults, classified as having severe (N = 88), moderate (N = 314), mild (N = 5477), and no anemia. Using propensity scores, patients with severe, mild, and moderate anemia were matched with patients with no anemia. Logistic regression was used to predict adverse postoperative outcomes. Sensitivity analyses were conducted limiting the study sample to patients who did not receive intra- or postoperative transfusion and to patients with and without preoperative cardiovascular comorbidities.

RESULTS

Patients with all levels of anemia had significantly higher risk of nearly all adverse outcomes than nonanemic patients in unadjusted and propensity-matched models. Patients with moderate and mild anemia were more likely to have prolonged length of hospitalization, experience 1 or more complications, and expire within 30 days of surgery compared with nonanemic patients. The association between anemia and adverse outcomes was found independently of intra- and postoperative transfusions, and was not more pronounced in patients with preoperative cardiovascular comorbidities.

CONCLUSION

All levels of anemia were significantly associated with prolonged length of hospitalization and poorer operative or 30-day outcomes in patients undergoing elective spine surgery. Our findings, using a large multi-institutional sample of prospectively collected data, suggests that anemia should be regarded as an independent risk factor for perioperative and postoperative complications that deserves attention prior to elective spine surgery.

The effects of non-leukoreduced red blood cell transfusions on microcirculation in mixed surgical patients

BACKGROUND

The impact of the storage process on oxygen-carrying properties of red blood cells and the efficacy of red blood cell (RBC) transfusions concerning tissue oxygenation remain an issue of debate in transfusion medicine. Storage time and leukocyte content probably interact since longer storage duration is thought to cause greater accumulation of leukocyte-derived cytokines and red blood cell injury.

OBJECTIVES

The aim of this study was to investigate the effects of storage and the efficacy of fresh (stored for less than 1 week) versus aged (stored for more than 3 weeks) non-leukoreduced RBC transfusions on sublingual microvascular density and flow in mixed surgical patients.

METHODS

Eighteen surgical patients were included in this study. Patients were randomly assigned into two groups receiving fresh (Group A) and aged (Group B) RBC transfusions. Sublingual microcirculatory functional capillary density (FCD) and microvascular flow index (MFI) were assessed using orthogonal polarization spectral (OPS) imaging. Measurements and collection of blood samples were performed after induction of general anesthesia, before RBC transfusion and 30 min after the RBC transfusion ended.

RESULTS

In both groups RBC transfusions caused an increase in hemoglobin concentration (p<0.001). RBC transfusions increased FCD in Group A (p<0.001), while FCD remained unaffected in Group B. Changes in MFI following RBC transfusion in both groups remained unaltered.

CONCLUSIONS

Fresh non-leukoreduced RBC transfusions but not RBCs stored for more than 3weeks, were effective in improving microciruculatory perfusion by elevating the number of perfused microvessels in mixed surgical patients.

Drivers of transfusion decision making and quality of the evidence in orthopedic surgery: a systematic review of the literature

Reasons for variation in transfusion practice in orthopedic surgery are not well understood. This systematic review identified and appraised the quality of the literature in this area to assess the impact of factors associated with the use of allogeneic red blood cell (RBC) transfusion in orthopedic procedures. MEDLINE and EMBASE databases were searched for relevant English language publications. Articles containing a range of MeSH and text terms regarding "blood transfusion," "predictors," and "multiple logistic regression" were retrieved. Articles that focused on patients undergoing orthopedic procedures and that met prespecified inclusion criteria were appraised in terms of potential bias and the appropriateness of statistical approach. A total of 3641 citations were retrieved, and 29 met the inclusion criteria for the review. Articles reported on a range of orthopedic procedures including total hip arthroplasty; total knee arthroplasty, total shoulder arthroplasty, and spinal surgery. Most studies were conducted in the United States (n = 12) or Canada (n = 5). Study quality was moderate; 50% or more of the quality criteria were assessed in 15 articles. Particular areas of concern were the lack of prospective studies, lack of clarity in defining the time interval between risk factor assessment and transfusion outcome, and lack of model validation. A narrative synthesis found that 2 factors consistently influenced the use of RBC transfusion-decreased hemoglobin (n = 25) and increased patient age (n = 18). Increased surgical complexity (n = 12), low body weight (n = 9), presence of additional comorbidities (n = 9), and female sex (n = 7) were also important factors. The general quality of the studies in the field is weak. However, low hemoglobin and increasing age were consistently identified as independent risk factors for RBC transfusion in orthopedic practice. Additional or alternative analytical approaches are required to obtain a more comprehensive, holistic understanding of the decision to transfuse RBCs to patients undergoing orthopedic surgery.

Transfusion in the critically ill: does it affect outcome?

Anemia and red blood cell (RBC) transfusions are common in critically ill and injured, trauma, and surgical patients. Tolerance of anemia is highly variable, depending on the presence of cardiovascular and other comorbid diseases that may diminish the hemodynamic response to a lower hemoglobin (Hb) level. The quest to define a minimum threshold Hb concentration at which patients achieve significant benefit to improve outcome has not yet been identified. Complications related to RBC transfusion are related to RBC storage and intrinsic properties of donor allogeneic RBCs, including bacterial contamination, transfusion-related acute lung injury, and transfusion-related immunomodulation. The best evidence related to transfusion-related outcome involves titrating transfusion requirements to parameters of severity of illness rather than arbitrarily defined Hb levels.

Detection, evaluation, and management of preoperative anaemia in the elective orthopaedic surgical patient: NATA guidelines

Previously undiagnosed anaemia is common in elective orthopaedic surgical patients and is associated with increased likelihood of blood transfusion and increased perioperative morbidity and mortality. A standardized approach for the detection, evaluation, and management of anaemia in this setting has been identified as an unmet medical need. A multidisciplinary panel of physicians was convened by the Network for Advancement of Transfusion Alternatives (NATA) with the aim of developing practice guidelines for the detection, evaluation, and management of preoperative anaemia in elective orthopaedic surgery. A systematic literature review and critical evaluation of the evidence was performed, and recommendations were formulated according to the method proposed by the Grades of Recommendation Assessment, Development and Evaluation (GRADE) Working Group. We recommend that elective orthopaedic surgical patients have a haemoglobin (Hb) level determination 28 days before the scheduled surgical procedure if possible (Grade 1C). We suggest that the patient's target Hb before elective surgery be within the normal range, according to the World Health Organization criteria (Grade 2C). We recommend further laboratory testing to evaluate anaemia for nutritional deficiencies, chronic renal insufficiency, and/or chronic inflammatory disease (Grade 1C). We recommend that nutritional deficiencies be treated (Grade 1C). We suggest that erythropoiesis-stimulating agents be used for anaemic patients in whom nutritional deficiencies have been ruled out, corrected, or both (Grade 2A). Anaemia should be viewed as a serious and treatable medical condition, rather than simply an abnormal laboratory value. Implementation of anaemia management in the elective orthopaedic surgery setting will improve patient outcomes.

Perioperative Coagulopathy, Bleeding, and Hemostasis During Cardiac Surgery

Cardiac surgery patients use 10%-25% of the blood products transfused annually in the United States. The transfusion of red blood cells or blood products has been the subject of intense scrutiny over the past 10 years. Bleeding after cardiac surgery can be surgical or nonsurgical and lead to hemodynamic compromise and surgical reexploration. Because hemorrhage and blood product transfusions are associated with multiple negative outcomes, including increased mortality, it is prudent to understand the mechanisms responsible for nonsurgical bleeding. This review focuses on the physiology of the normal coagulation and fibrinolysis, risk factors associated with patients presenting for cardiac surgery, impairments of normal hemostasis associated with cardiac surgery and cardiopulmonary bypass (CPB), and potential interventions to reduce perioperative blood loss and blood transfusion.

Patient blood management - a new paradigm for transfusion medicine?

The saving of many lives in history has been duly credited to blood transfusions. What is frequently overlooked is the fact that, in light of a wealth of evidence as well as other management options, a therapy deemed suitable yesterday may no longer be the first choice today. Use of blood has not been based upon scientific evaluation of benefits, but mostly on anecdotal experience and a variety of factors are challenging current practice. Blood is a precious resource with an ever limiting supply due to the aging population. Costs have also continually increased due to advances (and complexities) in collection, testing, processing and administration of transfusion, which could make up 5% of the total health service budget. Risks of transfusions remain a major concern, with advances in blood screening and processing shifting the profile from infectious to non‐infectious risks. Most worrying though, is the accumulating literature demonstrating a strong (often dose‐dependent) association between transfusion and adverse outcomes. These include increased length of stay, postoperative infection, morbidity and mortality. To this end, a recent international consensus conference on transfusion outcomes (ICCTO) concluded that there was little evidence to corroborate that blood would improve patients’ outcomes in the vast majority of clinical scenarios in which transfusions are currently routinely considered; more appropriate clinical management options should be adopted and transfusion avoided wherever possible. On the other hand, there are patients for whom the perceived benefits of transfusion are likely to outweigh the potential risks. Consensus guidelines for blood component therapy have been developed to assist clinicians in identifying these patients and most of these guidelines have long advocated more conservative ‘triggers’ for transfusion. However, significant variation in practice and inappropriate transfusions are still prevalent. The ‘blood must always be good philosophy’ continues to permeate clinical practice. An alternative approach, however, is being adopted in an increasing number of centres. Experience in managing Jehovah’s Witness patients has shown that complex care without transfusion is possible and results are comparable with, if not better than those of transfused patients. These experiences and rising awareness of downsides of transfusion helped create what has become known as ‘patient blood management’. Principles of this approach include optimizing erythropoiesis, reducing surgical blood loss and harnessing the patient’s physiological tolerance of anaemia. Treatment is tailored to the individual patient, using a multidisciplinary team approach and employing a combination of modalities. Results have demonstrated reduction of transfusion, improved patient outcomes and patient satisfaction. Significant healthcare cost savings have also followed. Despite the success of patient blood management programmes and calls for practice change, the potential and actual harm to patients caused through inappropriate transfusion is still not sufficiently tangible for the public and many clinicians. This has to change. The medical, ethical, legal and economic evidence cannot be ignored. Patient blood management needs to be implemented as the standard of care for all patients.

Risk associated with preoperative anemia in cardiac surgery: a multicenter cohort study

BACKGROUND

Preoperative anemia is an important risk factor for perioperative red blood cell transfusions, which are associated with postoperative morbidity and mortality. Whether preoperative anemia also is an independent risk factor for adverse outcomes after cardiac surgery, however, has not been fully elucidated.

METHODS AND RESULTS

In this multicenter cohort study, data were collected on 3500 consecutive patients who underwent cardiac surgery during 2004 at 7 academic hospitals. The prevalence of preoperative anemia, defined as hemoglobin <12.5 g/dL, and its unadjusted and adjusted relationships with the composite outcome of in-hospital death, stroke, or acute kidney injury were obtained. The overall prevalence of preoperative anemia was 26%, with values ranging from 22% to 30% at the participating hospitals. After the exclusion of patients who had severe preoperative anemia (hemoglobin <9.5 g/dL) or preoperative kidney failure and those who underwent emergency surgery, the composite outcome was observed in 7.5% of patients (247 of 3286). The unadjusted odds ratio for the composite outcome in anemic versus nonanemic patients was 3.6 (95% confidence interval, 2.7 to 4.7). The risk-adjusted odds ratios, obtained by multivariable logistic regression and propensity-score matching to control for important confounders (including comorbidities, institution, surgical factors, and blood transfusion), were 2.0 (95% confidence interval, 1.4 to 2.8) and 1.8 (95% confidence interval, 1.2 to 2.7), respectively.

CONCLUSIONS

Preoperative anemia is independently associated with adverse outcomes after cardiac surgery. Future studies should determine whether therapies aimed at treating preoperative anemia would improve the outcomes of patients undergoing cardiac surgery.

Perioperative blood transfusion and blood conservation in cardiac surgery: the Society of Thoracic Surgeons and The Society of Cardiovascular Anesthesiologists clinical practice guideline

BACKGROUND

A minority of patients having cardiac procedures (15% to 20%) consume more than 80% of the blood products transfused at operation. Blood must be viewed as a scarce resource that carries risks and benefits. A careful review of available evidence can provide guidelines to allocate this valuable resource and improve patient outcomes.

METHODS

We reviewed all available published evidence related to blood conservation during cardiac operations, including randomized controlled trials, published observational information, and case reports. Conventional methods identified the level of evidence available for each of the blood conservation interventions. After considering the level of evidence, recommendations were made regarding each intervention using the American Heart Association/American College of Cardiology classification scheme.

RESULTS

Review of published reports identified a high-risk profile associated with increased postoperative blood transfusion. Six variables stand out as important indicators of risk: (1) advanced age, (2) low preoperative red blood cell volume (preoperative anemia or small body size), (3) preoperative antiplatelet or antithrombotic drugs, (4) reoperative or complex procedures, (5) emergency operations, and (6) noncardiac patient comorbidities. Careful review revealed preoperative and perioperative interventions that are likely to reduce bleeding and postoperative blood transfusion. Preoperative interventions that are likely to reduce blood transfusion include identification of high-risk patients who should receive all available preoperative and perioperative blood conservation interventions and limitation of antithrombotic drugs. Perioperative blood conservation interventions include use of antifibrinolytic drugs, selective use of off-pump coronary artery bypass graft surgery, routine use of a cell-saving device, and implementation of appropriate transfusion indications. An important intervention is application of a multimodality blood conservation program that is institution based, accepted by all health care providers, and that involves well thought out transfusion algorithms to guide transfusion decisions.

CONCLUSIONS

Based on available evidence, institution-specific protocols should screen for high-risk patients, as blood conservation interventions are likely to be most productive for this high-risk subset. Available evidence-based blood conservation techniques include (1) drugs that increase preoperative blood volume (eg, erythropoietin) or decrease postoperative bleeding (eg, antifibrinolytics), (2) devices that conserve blood (eg, intraoperative blood salvage and blood sparing interventions), (3) interventions that protect the patient's own blood from the stress of operation (eg, autologous predonation and normovolemic hemodilution), (4) consensus, institution-specific blood transfusion algorithms supplemented with point-of-care testing, and most importantly, (5) a multimodality approach to blood conservation combining all of the above.

Blood conservation strategies in cardiac surgery

Despite the continuous efforts to increase the safety of blood components, red blood cell transfusions remain associated with some risks and side effects. Therefore, numerous techniques have been developed to decrease blood use, but they also carry risks and bear costs. Most of them are frequently used in cardiac surgery, which still consumes a large part of the available blood supply. Among western countries the use of alternative techniques, but also transfusion practice, has been shown to vary markedly. 'Blood conservation' is a global concept engulfing all possible strategies aimed at reducing patients' exposure to allogeneic blood components. The development of the 'best strategy' consists of the selection of those techniques that are most appropriate to the local specific situation. It implies the establishment of a reliable system, collecting data both at the surgical team and at the medical level.