Postoperative blood salvage: outside the controlled world of the blood bank

Shed Pleural Blood from Traumatic Hemothorax Contains Elevated Levels of Pro-Inflammatory Cytokines

PURPOSE

The autotransfusion of unwashed (or unprocessed) shed hemothorax blood (USHB) in trauma patients is widely assumed to be beneficial; however, the inflammatory potential of shed pleural blood has not been thoroughly studied. Since previous studies have documented marked changes in coagulation function of shed pleural blood, we hypothesized that its level of inflammatory cytokines would be elevated.

METHODS

A prospective observational study of trauma patients in whom cytokine levels from USHB were compared to venous samples from healthy volunteers was conducted. Differences between the cytokine content of patient-derived samples were compared to those from healthy subjects.

RESULTS

There was a statistically significant increase in pro-inflammatory cytokines (IL-6, IL-8, TNFα, GM-CSF), a pro-inflammatory Th-1 cytokine (IFNγ), and anti-inflammatory Th-2 cytokines (IL-4 and IL-10) in shed pleural blood over four hours when compared with samples from healthy controls (P <0.05). Cytokine levels in USHB are approximately 10- to 100-fold higher compared with healthy control venous samples.

CONCLUSIONS

USHB, even collected within the accepted four-hour window, contains significantly elevated cytokine levels, suggesting the potential for deleterious effects from autotransfusion. Randomized trials are needed to determine the safety and efficacy of autotransfusion in trauma patients.

Postoperative autotransfusion drain after total hip arthroplasty: a meta-analysis of randomized controlled trials

The use of a postoperative autotransfusion drain (PATD) to reduce allogenic blood transfusions in total hip arthroplasty (THA) remains controversial. Therefore, we conducted a meta-analysis to evaluate the efficacy and safety of this technique. Randomized controlled trials (RCTs) were identified from PubMed, Embase, and the Cochrane Central Register of Controlled Trials (CENTRAL). Thirteen RCTs (1,424 participants) were included in our meta-analysis. The results showed that PATD reduced the rate of allogenic transfusions (RR = 0.56; 95% CI [0.40, 0.77]) and total blood loss (MD = -196.04; 95% CI [-311.01, -81.07]). Haemoglobin (Hb) levels were higher in the PATD group on postoperative day 1 (MD = 0.28; 95% CI [0.06, 0.49]), but no significant differences on postoperative days 2 or 3 (MD = 0.29; 95% CI [-0.02, 0.60]; MD = 0.26; 95% CI [-0.04, 0.56]; respectively). There were no differences in length of hospital stay (MD = -0.18; 95% CI [-0.61, 0.25]), febrile reaction (RR = 1.26; 95% CI [0.95, 1.67]), infection (RR = 0.95; 95% CI [0.54, 1.65]), wound problems (RR = 1.07; 95% CI [0.87, 1.33]), or serious adverse events (RR = 0.59; 95% CI [0.10, 3.58]). Our findings suggest that PATD is effective in reducing the rate of allogenic transfusion. However, the included studies are inadequately powered to conclusively determine the safety of this technique.

Indications and organisational methods for autologous blood transfusion procedures in Italy: results of a national survey

INTRODUCTION

Pre-operative donation of autologous blood is a practice that is now being abandoned. Alternative methods of transfusing autologous blood, other than predeposited blood, do however play a role in limiting the need for transfusion of allogeneic blood. This survey of autologous blood transfusion practices, promoted by the Italian Society of Transfusion Medicine and Immunohaematology more than 2 years after the publication of national recommendations on the subject, was intended to acquire information on the indications for predeposit in Italy and on some organisational aspects of the alternative techniques of autotransfusion.

MATERIALS AND METHODS

A structured questionnaire consisting of 22 questions on the indications and organisational methods of autologous blood transfusion was made available on a web platform from 15 January to 15 March, 2013. The 232 Transfusion Services in Italy were invited by e-mail to complete the online survey.

RESULTS

Of the 232 transfusion structures contacted, 160 (69%) responded to the survey, with the response rate decreasing from the North towards the South and the Islands. The use of predeposit has decreased considerably in Italy and about 50% of the units collected are discarded because of lack of use. Alternative techniques (acute isovolaemic haemodilution and peri-operative blood salvage) are used at different frequencies across the country.

DISCUSSION

The data collected in this survey can be considered representative of national practice; they show that the already very limited indications for predeposit autologous blood transfusion must be adhered to even more scrupulously, also to avoid the notable waste of resources due to unused units.Users of alternative autotransfusion techniques must be involved in order to gain a full picture of the degree of use of such techniques; multidisciplinary agreement on the indications for their use is essential in order for these indications to have an effective role in "patient blood management" programmes.

Does single use of an autologous transfusion system in TKA reduce the need for allogenic blood?: a prospective randomized trial

BACKGROUND

Mechanical autotransfusion systems for washed shed blood (WSB) were introduced to reduce the need for postoperative allogenic blood transfusions (ABTs). Although some authors have postulated decreased requirements for ABT by using autologous retransfusion devices, other trials, mostly evaluating retransfusion devices for unwashed shed blood (USB), verified a small or no benefit in reducing the need for postoperative ABT. Because of these contradictory findings it is still unclear whether autologous retransfusion systems for WSB can reduce transfusion requirements.

QUESTIONS/PURPOSES

We therefore asked whether one such autologous transfusion system for WSB can reduce the requirements for postoperative ABT.

METHODS

In a prospective, randomized, controlled study, we enrolled 151 patients undergoing TKA. In Group A (n=76 patients), the autotransfusion system was used for a total of 6 hours (intraoperatively and postoperatively) and the WSB was retransfused after processing. In Control Group B (n=75 patients), a regular drain without suction was used. We used signs of anemia and/or a hemoglobin value less than 8 g/dL as indications for transfusion. If necessary, we administered one or two units of allogenic blood.

RESULTS

Twenty-three patients (33%) in Group A, who received an average of 283 mL (range, 160-406 mL) of salvaged blood, needed a mean of 2.1 units of allogenic blood, compared with 23 patients (33%) in Control Group B who needed a mean of 2.1 units of allogenic blood.

CONCLUSIONS

We found the use of an autotransfusion system did not reduce the rate of postoperative ABTs.

LEVEL OF EVIDENCE

Level II, therapeutic study. See the Guidelines for Authors for a complete description of levels of evidence.

The cost of post-operative shed blood salvage after total knee arthroplasty: an analysis of 1,093 consecutive procedures

BACKGROUND

Requirements for allogeneic red cell transfusion after total knee arthroplasty are still high (20-50%), and salvage and reinfusion of unwashed, filtered post-operative shed blood is an established method for reducing transfusion requirements following this operation. We performed a cost analysis to ascertain whether this alternative is likely to be cost-effective.

MATERIALS AND METHODS

Data from 1,093 consecutive primary total knee arthroplasties, managed with (reinfusion group, n=763) or without reinfusion of unwashed salvaged blood (control group, n=330), were retrospectively reviewed. The costs of low-vacuum drains, shed blood collection canisters (Bellovac ABT, Wellspect HealthCare and ConstaVac CBC II, Stryker), shed blood reinfusion, acquisition and transfusion of allogeneic red cell concentrate, haemoglobin measurements, and prolonged length of hospital stay were used for the blood management cost analysis.

RESULTS

Patients in the reinfusion group received 152±64 mL of red blood cells from postoperatively salvaged blood, without clinically relevant incidents, and showed a lower allogeneic transfusion rate (24.5% vs. 8.5%, for the control and reinfusion groups, respectively; p =0.001). There were no differences in post-operative infection rates. Patients receiving allogeneic transfusions stayed in hospital longer (+1.9 days [95% CI: 1.2 to 2.6]). As reinfusion of unwashed salvaged blood reduced the allogeneic transfusion rate, both reinfusion systems may provide net savings in different cost scenarios (€ 4.6 to € 106/patient for Bellovac ABT, and € -51.9 to € 49.9/patient for ConstaVac CBCII).

DISCUSSION

Return of unwashed salvaged blood after total knee arthroplasty seems to save costs in patients with pre-operative haemoglobin between 12 and 15 g/dL. It is not cost-saving in patients with a pre-operative haemoglobin >15 g/dL, whereas in those with a pre-operative haemoglobin <12 g/dL, although cost-saving, its efficacy could be increased by associating some other blood-saving method.

Blood transfusion and cytokines' changes in total knee replacement

INTRODUCTION

The aim of this prospective comparative study was to evaluate the serum levels of different cytokines and the frequency of adverse reactions and wound infections in patients who underwent total knee replacement (TKR) and were not transfused or received either allogeneic blood transfusion or postoperative auto-transfusion (PAT) with unwashed shed blood.

MATERIALS AND METHODS

A total of 248 patients were categorized into three groups; in Group 0 (n 85) patients received no blood transfusion, in Group 1 (n 92) patients received PAT and in Group 2 (n 71) patients received allogeneic blood transfusion. Patient's demographic and clinical data including age, gender, body mass index, preoperative haemoglobin value, adverse reactions and complications were documented. The serum levels of IL-1b, IL-6, IL-8, IL-10 and TNF were measured preoperatively, and on the first, third and fifth postoperative day. A statistical analysis of the results was performed.

RESULTS

A significant elevation of cytokine values were observed during the first five postoperative days in patients who received blood transfusion after TKR. Adverse reactions (chills and pyrexia) were also more common in patients who received blood transfusion, whereas superficial infections were more common in patients who received allogeneic blood transfusion.

CONCLUSION

The immunological status-as expressed by the measured cytokine levels-is altered in patients receiving blood transfusion compared to patients receiving no blood transfusion during the first five postoperative days. PAT is preferable to allogeneic blood transfusion in terms of the rate of adverse reactions and superficial wound infections.

Proinflammatory cytokines and complement activation in salvaged blood from abdominal aortic aneurism surgery and total hip replacement surgery

BACKGROUND

Levels of proinflammatory mediators in unwashed salvaged blood from abdominal aortic aneurism (AAA) surgery are unknown. We hypothesized that there are higher levels of these mediators in unwashed blood salvaged in AAA surgery compared to hip replacement surgery.

STUDY DESIGN AND METHODS

Ten patients scheduled for AAA surgery (Group A) and 10 patients for total hip replacement surgery (Group H) were included. Blood samples from the autotransfusion set were obtained during surgery and arterial samples before, during, and 6 hours after surgery. Determination of interleukin (IL)-1β, IL-6, IL-8, tumor necrosis factor-α, activated complement 3 (C3a), and high-sensitivity C-reactive protein (CRP) were performed. Salvaged blood was not retransfused.

RESULTS

Levels (median [range]) of IL-8 in blood in the salvage system were higher in Group A versus Group H (215.3 [22.5-697.2] vs. 35.3 [16.7-66.6] pg/mL; p = 0.002). Higher levels of IL-6 were also seen in Group A versus Group H (60.0 [52.6-62.2] vs. 42.34 [19.4-62.2] pg/mL; p = 0.049). Levels of IL-6 in blood sampled during surgery were approximately fivefold higher in Group A versus Group H (p = 0.023), whereas approximately 70% higher levels of C3a were observed in Group H versus Group A (p = 0.021). Postoperative concentrations of IL-1β (p = 0.002), IL-6 (p = 0.001), and IL-8 (0.005) were higher in Group A versus Group H.

CONCLUSION

Salvaged blood in AAA surgery contains substantially higher levels of proinflammatory mediators compared to blood in total hip replacement surgery.

Hemolysis and red blood cell mechanical fragility in shed blood after total knee arthroplasty

BACKGROUND

There are several options for the salvage of postoperative shed red blood cells (RBCs). This study compared the characteristics of the returned RBCs collected using two different devices: one that washes and one that does not wash the collected RBCs.

STUDY DESIGN AND METHODS

Forty patients undergoing first-time total knee arthroplasty consented to participate. Twenty patients were operated on by a surgeon who routinely uses a device that does not wash the shed RBCs (unwashed group), the other 20 patients were operated on by surgeons who routinely use a device that washes and concentrates the collected RBCs (washed group). A small quantity of postprocessing RBCs were collected immediately before reinfusion and the amount of plasma-free hemoglobin (PFHb), and the mechanical fragility index (MFI) of the returned RBCs were determined.

RESULTS

The patients in both groups were well matched for age, sex, and length of stay. The mean percent hemolysis of the returned RBCs was not different between the unwashed and washed groups (1.22±0.30 vs. 1.24±0.42, p=0.895), while the mean total amount of returned PFHb was not different (0.51±0.12 g vs. 0.55±0.35 g, p<0.615). The ratio of total PFHb:total returned Hb was significantly lower for the washed group (0.0087±0.0023 vs. 0.0035±0.0011, p<0.0001). The MFI was higher in the washed group (1.71±0.55 vs. 0.53±0.42, p<0.001).

CONCLUSIONS

The washing device returned more Hb to the patients relative to the amount of free Hb.

Sedimentation method for preparation of postoperatively salvaged unwashed shed blood in orthopaedic surgery

BACKGROUND

Salvage and return of unwashed shed blood (USB) after total knee replacement (TKR) is an established blood-saving technique, but some authors question its efficacy and safety and suggest that the shed blood be washed before returning. We evaluated a colloid-based sedimentation method for improving and standardizing the quality of USB collected after TKR without the need for washing.

METHODS

Experiments were performed to find the optimal colloid dose and sedimentation time using diluted donated venous blood. USB samples (n=52) were drawn from the reinfusion bag and mixed with hydroxyethyl starch or gelatine solutions (15-30%, colloid solution volume/total volume × 100). USB red blood cells (RBCs) were allowed to settle by gravity for 30 min, supernatant was evacuated from the syringe, and RBC concentrate was analysed. RBC recovery and other blood cell and chemical removal were calculated according to changes in USB volume and haematocrit. Twenty-five samples from leucodepleted packed RBCs were analysed as a comparator group.

RESULTS

Mean haemoglobin (Hb) of USB was 10.9 g dl(-1). After colloid treatment, 90% of RBCs were recovered, and USB Hb was similar to that of leucodepleted packed RBCs (n=25) (18.9 vs 19.6 g dl(-1), respectively; P=NS). In addition, the procedure reduced USB content of leucocytes (60%), platelets (48%), total protein (76%), cytokines (70-77%), and plasma-free haemoglobin (53%), without major differences between colloids.

CONCLUSIONS

Sedimentation of USB with colloid solutions provides a low-cost alternative for improving and standardizing the quality of salvaged USB after TKR.

The future of blood management

An evolving understanding of the consequences of allogeneic blood transfusion and escalating costs of providing allogeneic blood have resulted in an interest in blood management. Understanding the consequences of allogeneic transfusion includes a recognition of the immunosuppressive effects of allogeneic transfusion, a growing awareness of transfusion-related acute lung injury, and a rediscovery of transfusion-associated circulatory overload. More recently, interest has focused on the effect of stored blood on patient outcome. Although this discussion is not all-inclusive, it is intended to show that many techniques can be applied to decrease the exposure to allogeneic blood.