Mortality, Morbidity and Related Outcomes Following Perioperative Blood Transfusion in Patients with Major Orthopaedic Surgery: A Systematic Review

Background

Benefits and risks of liberal and restrictive transfusion regimens are under on-going controversial discussion. This systematic review aimed at assessing both regimens in terms of pre-defined outcomes with special focus on patients undergoing major orthopaedic surgery.

Methods

We performed a literature search for mortality, morbidity and related outcomes following peri-operative blood transfusion in patients with major orthopaedic surgery in electronic databases. Combined outcome measure estimates were calculated within the scope of meta-analyses including randomised clinical trials comparing restrictive versus liberal blood transfusion regimens (e.g. MH risk ratio, Peto odds ratio).

Results

A total of 880 publications were identified 15 of which were finally included (8 randomised clinical trials (RCTs) with 3,693 patients and 6 observational studies with 4,244,112 patients). Regarding RCTs, no significant differences were detected between the transfusion regimes for all primary outcomes (30-day mortality, thromboembolic events, stroke/transitory ischaemic attack, myocardial infarction, wound infection and pneumonia) and a secondary outcome (length of hospital stay), whereas there was a significantly reduced risk of receiving at least one red blood concentrate under a restrictive regimen.

Conclusion

The results of this systematic review do not suggest an increased risk associated with either a restrictive or a liberal transfusion regimen in patients undergoing major orthopaedic surgery.

The effects of storage of red blood cells on the development of postoperative infections after noncardiac surgery

BACKGROUND

Prolonged storage of red blood cells (RBCs) is a potential risk factor for postoperative infections. The objective of this study was to examine the effect of age of RBCs transfused on development of postoperative infection.

STUDY DESIGN AND METHODS

In this prospective, double-blind randomized trial, 199 patients undergoing elective noncardiac surgery and requiring RBC transfusion were assigned to receive nonleukoreduced RBCs stored for not more than 14 days ("fresh blood" group, n = 101) or for more than 14 days ("old blood" group, n = 98). The primary outcome was occurrence of infection within 28 days after surgery; secondary outcomes were postoperative acute kidney injury (AKI), in-hospital and 90-day mortality, admission to intensive care unit, and hospital length of stay (LOS). As older blood was not always available, an "as-treated" (AT) analysis was also performed according to actual age of the RBCs transfused.

RESULTS

The median [interquartile range] storage time of RBCs was 6 [5-10] and 15 [11-20] days in fresh blood and in old blood groups, respectively. The occurrence of postoperative infection did not differ between groups (fresh blood 22% vs. old blood 25%; relative risk [RR], 1.17; confidence interval [CI], 0.71-1.93), although wound infections occurred more frequently in old blood (15% vs. 5%; RR, 3.09; CI, 1.17- 8.18). Patients receiving older units had a higher rate of AKI (24% vs. 6%; p < 0.001) and, according to AT analysis, longer LOS (mean difference, 3.6 days; CI, 0.6-7.5).

CONCLUSION

Prolonged RBC storage time did not increase the risk of postoperative infection. However, old blood transfusion increased wound infections rate and incidence of AKI.

Allogeneic Blood Transfusion Is a Significant Risk Factor for Surgical-Site Infection Following Total Hip and Knee Arthroplasty: A Meta-Analysis

BACKGROUND

Blood loss occurs significantly more frequently during total hip and knee arthroplasty than among any other type of orthopedic operation, which can sometimes lead to requiring a blood transfusion. Although allogeneic blood transfusion has been identified as a risk factor for postoperative surgical-site infection following arthroplasty, results are inconclusive. The purpose of this study was to conduct a systematic meta-analysis to investigate whether having an allogeneic blood transfusion significantly increases the risk for surgical-site infection, particularly after total hip and knee arthroplasty.

METHODS

We performed a systematic review and meta-analysis using random-effect models. Using an electronic database search, we selected 6 studies that included data on 21,770 patients and among these studies compared the postoperative infection rate between an allogeneic blood-transfusion exposure group and a nonexposure group. We calculated the pooled odds ratios and 95% confidence intervals for the groups.

RESULTS

The prevalences of surgical-site infections in our pooled analyses were 2.88% and 1.74% for the transfusion and nontransfusion groups, respectively. The allogeneic blood transfusion group had a significantly higher frequency of surgical-site infections based on pooled analysis using a random-effect model (pooled odds ratio = 1.71, 95% confidence interval: 1.23-2.40, P = .002).

CONCLUSION

Allogeneic blood transfusion is a significant risk factor for increasing the surgical-site infection rate after total hip and knee arthroplasty.

Cost-effectiveness of post-operative cell salvage in total knee arthroplasty. Should we continue to recommend its use today?

OBJECTIVES

Total knee arthroplasty (TKA) has a high transfusion rate. In our protocol, the use of postoperative cell salvage is indicated in patients with contraindications to tranexamic acid (TA). An analysis was performed on the effect of post-operative cell salvage (POCS) regarding transfusion rate and costs in patients undergoing TKA.

MATERIAL AND METHODS

A prospective analysis was conducted on 518 patients, of whom 434 received TA, and 84 were contraindicated. The red cell mass, blood volume, and the percentage of lost blood volume were calculated. Incidents associated with the use of post-operative re-perfusion of drained blood and the rate of transfusion were recorded. An analysis was performed on the costs associated with allogeneic transfusion prevention methods.

RESULTS

A POCS drain was not inserted in 10 out of the 84 patients not candidates for TA. In the 74 in which it was placed, 158±72ml of red cell mass was reinfused. The allogeneic transfusion rate was 36%, and was 52% in those with no drain inserted. Relative risk of transfusion using POCS was 0.69 (0.41 to 1.16) with an absolute risk reduction of 16% (-8 to 40%). The number needed to treat to avoid allogeneic transfusion was 7. The direct costs to avoid allogeneic transfusion were €1,610. No complications associated with blood re-infusion were observed.

CONCLUSIONS

The use of POCS would be required in 7 patients after TKA to avoid one allogeneic transfusion with a cost over 10 times that of a transfusion of red cell concentrates.

Clinical effects of red blood cell storage

BACKGROUND

Well-characterized biochemical, structural, and physiological changes occur when red blood cells (RBCs) are stored for a period of time and are collectively called the storage lesion.

METHODS

Key study results are summarized and contrasted and new data from recently completed randomized controlled trials will be discussed.

RESULTS

It is unclear whether in vitro changes to RBCs that occur during storage are clinically relevant. The clinical effects of RBC storage have been the focus of observational studies in recent years. However, these studies lack any consensus, possibly because of methodological limitations.

CONCLUSIONS

The clinical significance of storing RBCs is controversial, although new data from randomized controlled trials of neonates and patients undergoing cardiac surgery suggest that the duration of RBC storage is not associated with adverse clinical outcomes in these patient populations.

Length of storage of transfused red blood cells and risk of prosthetic joint infection after primary knee arthroplasty

The aim of our study was to determine the potential influence of blood transfusion and the length of storage of packed red blood cells (RBC) on prosthetic joint infection after primary knee arthroplasty. From November 2007 to November 2009, all variables potentially associated with deep infection were registered in 1331 consecutive patients who underwent total knee arthroplasty. Infection was diagnosed in 32 (2.4%) patients. After adjusting for important variables, blood transfusion with RBCs stored >14days was the strongest predictive factor for prosthetic joint infection within 90days after primary knee arthroplasty (OR: 5.9, 95% CI: 2.6-13.2, P < 0.001). Blood saving techniques are desirable to reduce perioperative blood transfusion.

Allogeneic blood transfusions and postoperative infections after total hip or knee arthroplasty

BACKGROUND

Up to 70% of patients who undergo total hip or total knee arthroplasty receive blood transfusions. Using data from more than 12,000 patients assessed in the Phase-III RECORD (Regulation of Coagulation in Orthopedic Surgery to Prevent Deep Venous Thrombosis and Pulmonary Embolism) studies, we investigated whether allogeneic blood transfusion increases the risk of postoperative infection compared with autologous blood transfusion or no transfusion.

METHODS

A post hoc analysis of the pooled RECORD data stratified patients into three groups according to the type of blood transfusion that they received: no transfusion (n = 6313), autologous blood transfusion (n = 1902), and allogeneic blood transfusion with or without autologous blood transfusion (n = 3962). The types of postoperative infection were recorded and included lower or upper respiratory tract and lung infection, bone and joint infection, wound inflammation or infection, urinary tract infection, and other infections.

RESULTS

The rates of infection in patients receiving no transfusion or autologous blood transfusion were similar; therefore, data from these two groups were combined. The rate of any infection was 9.9% (392 of 3962) in patients receiving allogeneic blood transfusion and 7.9% (646 of 8215) in patients not receiving allogeneic blood transfusion with or without autologous blood transfusion (p = 0.003). The rates of lower or upper respiratory tract and lung infection (2.1% [eighty-five of 3962] versus 1.3% [109 of 8215]; p = 0.002) and of wound inflammation or infection (2.4% [ninety-four of 3962] versus 1.7% [138 of 8215]; p = 0.046) were significantly higher in patients receiving allogeneic blood transfusion compared with patients not receiving allogeneic blood transfusion. When comparing patients who had received allogeneic blood transfusion with those who had not received allogeneic blood transfusion, the rates of bone and joint infection (0.4% [fourteen of 3962] versus 0.2% [eighteen of 8215]; p = 0.056), of urinary tract infection (3.1% [123 of 3962] versus 2.5% [209 of 8215]; p = 0.551), and of other infections (3.0% [120 of 3962] versus 2.7% [225 of 8215]; p = 0.308) were not significantly different.

CONCLUSIONS

The rates of any infection, lower or upper respiratory tract and lung infection, and wound inflammation or infection were significantly increased after elective total hip or total knee arthroplasty in patients receiving allogeneic blood transfusion compared with those receiving autologous blood transfusion or no blood transfusion.

Relationship between red cell storage duration and outcomes in adults receiving red cell transfusions: a systematic review

INTRODUCTION

The duration of red blood cell (RBC) storage before transfusion may alter RBC function and supernatant and, therefore, influence the incidence of complications or even mortality.

METHODS

A MEDLINE search from 1983 to December 2012 was performed to identify studies reporting age of transfused RBCs and mortality or morbidity in adult patients.

RESULTS

Fifty-five studies were identified; most were single-center (93%) and retrospective (64%), with only a few, small randomized studies (eight studies, 14.5%). The numbers of subjects included ranged from eight to 364,037. Morbidity outcomes included hospital and intensive care unit (ICU) length of stay (LOS), infections, multiple organ failure, microcirculatory alterations, cancer recurrence, thrombosis, bleeding, vasospasm after subarachnoid hemorrhage, and cognitive dysfunction. Overall, half of the studies showed no deleterious effects of aged compared to fresh blood on any endpoint. Eleven of twenty-two (50%) studies reported no increased mortality, three of nine (33%) showed no increased LOS with older RBCs and eight of twelve (66%) studies showed no increased risks of organ failure. Ten of eighteen (55%) studies showed increased infections with transfusion of older RBCs. The considerable heterogeneity among studies and numerous methodological flaws precluded a formal meta-analysis.

CONCLUSIONS

In this systematic review, we could find no definitive argument to support the superiority of fresh over older RBCs for transfusion.

Estimating the transfusion risk following total knee arthroplasty

Patients undergoing total knee arthroplasty (TKA) are likely to receive a blood transfusion, which may increase the risk of complications and prolong hospital stay. Considerable variation exists in transfusion practice among orthopedic surgeons following elective TKA. Previous studies have investigated the relationship between preoperative risk factors and the requirement for blood transfusions in patients undergoing a total hip or knee arthroplasty, but few have focused on transfusion risk in those specifically undergoing TKA.The authors performed a retrospective review of a prospectively collected database of 2281 patients undergoing unilateral TKA in a district general hospital over a 10-year period. Multiple regression analysis models were used to identify risk factors associated with postoperative blood transfusion. A predictive model was created based on the regression coefficients and factor levels. The risk of transfusion was independently predicted by the patients' age at surgery (P<.001), preoperative hemoglobin (P<.001), weight (P=.009) and lateral retinacular release (P<.001). The preoperative variables of age, hemoglobin, and weight were incorporated into a model to provide an estimation of the transfusion risk. The area under the receiver operating characteristic curve was 74% (95% confidence interval, 70%-77.5%). This study identifies risk factors independently associated with the risk of requiring a blood transfusion following TKA. The predictive model stratifies the risk according to the individual patient in the preoperative setting, allowing preventative measures to take place preoperatively. It also helps in the counseling of patients at high risk of requiring a postoperative blood transfusion.