Are leukocytes in salvaged washed autologous blood harmful for the recipient? The results of a pilot study

Effects of the Sangvia blood collection system on patients undergoing elective hip surgery

We have conducted a randomized controlled study where 164 patients were randomized to receive autologous salvaged blood collected by Sangvia™ Blood Salvage System or allogeneic red cell concentrates if transfusion was indicated by clinical judgement. The study was powered to detect if transfusion of autologous blood reduced the occurrence of postoperative infections. We found no statistical significant difference in postoperative infection rate between the groups, but this may be due to the fact that postoperative infections were diagnosed in only five patients. Increased C-reactive protein concentrations slightly above level of significance indicate that autologous blood transfusions stimulate the patient's immune system. However, there was no indication of increased transfusion reaction rate, including febrile reactions, in the autologous group. Transfusion of autologous blood did not reduce the use of allogeneic red cell concentrates. The mean use of allogeneic red cell concentrates was 0.93 units (both groups combined), indicating that the transfusion policy may have been too liberal. There was a highly significant inverse correlation between pre-operative haemoglobin concentration and transfusion of allogeneic blood. In a patient population with a low frequency of postoperative infection, a larger study is needed to clarify if autologous salvaged blood protects against postoperative infections.

Processing of autologous bone marrow cells by apheresis technology for cell-based cardiovascular regeneration

BACKGROUND AIMS

Bone marrow (BM)-derived mononuclear cell (MNC) preparations are increasingly used in experimental studies exploring the potential effect of progenitor cell-derived therapies in cardiocirculatory diseases. We analyzed the cellular BM composition, side-effects and other process-related variables of BM harvest and BM-MNC preparation in 80 patients with cardiovascular disease.

METHODS

BM (median 828 mL, range 223-1038 mL) was collected from the iliac crest. After BM harvest the MNC fraction was enriched by semi-automatic apheresis to reduce the total volume of the transplant. Autologous red blood cells (RBC) were salvaged from the initial BM harvest and autotransfused to the patients.

RESULTS

There were no serious side-effects related to BM collection, particularly no serious bleeding complications. Twenty- five of 80 (31%) patients developed mild pain. BM harvest resulted in the collection of a median of 2.8 × 10(9) MNC, containing a median of 66.5 × 10(6) CD34/45 cells, 39.5 × 10(6) CD133/45 cells and 50.3 × 10(6) CD34/CD133 cells. Apheresis technology-based MNC enrichment of harvested BM resulted in a progenitor cell recovery of 69-75.3% of total cells. Additional salvage of RBC from the initial BM harvest resulted in the recovery of a median of 175.0 mL autologous RBC mass. Transfusion of salvaged RBC was well tolerated and resulted in a significant increase in hemoglobin levels.

CONCLUSIONS

Collection of BM of up to 1 L in combination with in vitro processing using a semi-automated apheresis device is a safe and feasible approach to increasing the number of progenitor cells necessary for cellular therapies, particularly when combined with RBC salvage.

The coagulopathy of cardiopulmonary bypass

There have been numerous publications on the coagulopathy of cardiopulmonary bypass (CPB). This review provides an introduction to the history and main components of current CPB circuits and summarizes the current knowledge of pathogenesis, prevention, and treatment of the CPB coagulopathy. It encompasses an overview of intra- and postoperative monitoring of coagulation with special emphasis on the near-patient testing, its main complications, and the transfusion support, while taking into account the major changes in the technology used and supportive care provided since its inception.

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.

Intraoperatively salvaged red blood cells contain nearly no functionally active platelets, but exhibit formation of microparticles: results of a pilot study in orthopedic patients

BACKGROUND

Previous data show improved clot formation after retransfusion of salvaged red blood cells (RBCs). This study was conducted to explore whether such RBCs contain clinically relevant numbers of active residual platelets (PLTs) or exhibit formation of microparticles (MPs).

STUDY DESIGN AND METHODS

Thirteen patients undergoing major orthopedic surgery were included in the study, and arterial blood samples from patients and samples from the retransfusion bag were analyzed with various PLT function tests and flow cytometry.

RESULTS

With commercial blood cell counters, the numbers of PLTs in the RBC unit were reduced to approximately 25% compared to patients' blood. In contrast, results from flow cytometry showed an 11- to 945-fold reduction in median counts referring to total PLTs and free PLTs. Interestingly, smaller quantities of PLT-derived MPs were found in samples from the retransfusion bag than in patients' arterial blood. Conversely, RBC- and white blood cell-derived MP counts were increased in the retransfusion bag compared to the patient. Rotational thrombelastometry and the Impact-R system (DiaMed) showed a pronounced impairment of PLT ability with regard to adhesion, aggregation, and clot formation. With the use of confocal microscopy, only a few free thrombocytes were detectable among the huge numbers of RBCs.

CONCLUSION

Only few free and thus active PLTs are detectable in processed RBCs. It seems very unlikely that these few PLTs can improve clot strength. Nevertheless, the impact of the detected MPs on thrombin generation needs to be clarified in further studies.

Substituting Citrate for Lactate in Peritoneal Dialysis Fluid Improves Ultrafiltration in Rats

Background

Exposure to peritoneal dialysis (PD) fluid induces an inflammatory response in the peritoneal cavity. Blockers of complement and coagulation have improved ultrafiltration in animal models of PD. Citrate is a clinically established anticoagulant that also blocks complement activation.

Objective

The aim of the present study was to evaluate the effects on ultrafiltration of a gradual substitution of citrate for lactate in an experimental model of PD.

Methods

Fractions (0, 5, 10, and 15 mmol/L) of the 40 mmol/L lactate buffer of filter-sterilized 2.5% glucose PD fluid were replaced by citrate. The modified fluids were compared in a rat model of single PD fluid exposure through an indwelling catheter. The initial kinetics of citrate and ionized calcium were evaluated in separate, single, short time dwell experiments.

Results

Replacing 10 and 15 mmol/L of the lactate buffer by sodium citrate significantly increased osmotic ultrafiltration (by 24.7% ± 7.7% at 10 mmol/L), net ultrafiltration, and glucose retention at 4 hours of dwell time in the rat model. Osmotic ultrafiltration was significantly correlated to citrate concentration and glucose concentration. Citrate was rapidly eliminated from the peritoneal cavity, concentrations falling to less than half in 1 hour and concentrations of calcium ions concomitantly normalized.

Conclusions

Substituting citrate for lactate induced a dose-dependent increase in ultrafiltration. Mechanisms probably involve the relation between diffusion and ultrafiltration, leading to increased glucose retention. The increase in ultrafiltration was quantitatively important at a citrate concentration (10 mmol/L) that is compatible with clinical applications of citrate.

The utility of the perioperative autologous transfusion system OrthoPAT in total hip replacement surgery: a prospective study

BACKGROUND

Total hip replacement (THR) is associated with a significant perioperative blood loss, and 30-50% of these patients receive allogeneic blood transfusion (ABT). We evaluated the clinical utility of washed shed blood (WSB) return to reduce ABT in THR patients.

STUDY DESIGN AND METHODS

Data from 108 consecutive THR patients were prospectively collected. WSB salvage and reinfusion (OrthoPAT) was intended for 60 (Reinfusion group), whereas the remaining 48 patients served as control group. Patients received ABT if haemoglobin <8 g/dl or clinical signs and symptoms of acute anemia.

RESULTS

WSB return was possible in 49 patients (205 +/- 151 ml of erythrocyte/patient), without any clinically relevant incident. Return of WSB decreased both the ABT rate (48 vs. 15%, for control and reinfusion groups, respectively; P = 0.001) and the ABT index (371 +/- 154 ml RBC vs. 53 +/- 117 ml RBC, respectively; P = 0.001), without differences between cemented and uncemented THR. In addition, patients from reinfusion group showed a trend to lower postoperative infection rate (10 vs. 2%, respectively; P = 0.086).

CONCLUSIONS

Perioperative salvage and return of WSB in THR seems to effectively reduce the requirements for ABT. However, for patients with preoperative Hb < 13 g/dl, some additional blood saving method should be associated to WSB return.

Complement split products and proinflammatory cytokines in intraoperatively salvaged unwashed blood during hip replacement: comparison between heparin-coated and non-heparin-coated autotransfusion systems

BACKGROUND AND OBJECTIVES

The aim of the present study was to investigate the quality of shed blood collected in a new intraoperative autotransfusion system (Sangvia, AstraTech, Sweden) and to study whether heparin-coated surfaces in the device reduce the production of inflammatory mediators.

MATERIAL AND METHODS

The study was randomized and prospective. Twelve total hip arthroplasty patients whose blood was collected with a device having a heparin-coated surface and 12 patients whose blood was collected with a device having a non-heparin-coated surface were included. Venous blood was drawn from the patients preoperatively. Intraoperatively 200 ml salvaged blood was collected and samples were also withdrawn; samples were obtained from the blood bag.

RESULTS

Compared to venous blood, elevated concentrations of interleukin 6 (IL-6), IL-8, C3a and polymorphonuclear elastase were found in collected blood. No significant differences in inflammatory mediators were found between the heparin-coated and the non-heparin-coated groups. The median haemoglobin concentration in the salvaged blood was 74 g/l in both groups. Plasma haemoglobin and potassium concentrations were also elevated. There were no significant differences between the groups.

CONCLUSION

The present study indicates that the blood salvaged intraoperatively contains elevated levels of complement split product and proinflammatory cytokines and that heparin-coated surfaces of the salvage device do not significantly influence the formation of inflammatory mediators.

Cell salvage in obstetrics

The safety of cell salvage in obstetrics has been questioned because of the presumed risk of precipitating amniotic fluid embolism and, to a lesser extent, maternal alloimmunisation. For these reasons, experience in this field is limited and has lagged far behind that in other surgical specialties. There has, however, been renewed interest in its use over recent years, mainly as a result of problems associated with allogeneic blood transfusion. Our aim was to review the medical literature to ascertain the principles of cell salvage, the ability of the process to remove contaminants, and its safety profile in the obstetric setting. The search engines PubMed and Google Scholar were used and relevant articles and websites hand searched for further references. Existing cell salvage systems differ in their ability to clear contaminants and all require the addition of a leucocyte depletion filter. Although large prospective trials of cell salvage with autotransfusion in obstetrics are lacking, to date, no single serious complication leading to poor maternal outcome has been directly attributed to its use. Cell salvage in obstetrics has been endorsed by several bodies based on current evidence. Current evidence supports the use of cell salvage in obstetrics, which is likely to become increasingly commonplace, but more data are required concerning its clinical use.

Perioperative management of pediatric patients with craniosynostosis

Craniosynostosis, premature closures of the skull sutures, results in dysmorphic features if left untreated. Brain growth and cognitive development may also be impacted. Craniosynostosis repair is usually performed in young infants and has its perioperative challenges. This article provides background information about the different forms of craniosynostosis, with an overview of associated anomalies, genetic influences, and their connection with cognitive function. It also discusses the anesthetic considerations for perioperative management, including blood-loss management and strategies to reduce homologous blood transfusions.

Impact of postoperative shed blood transfusion, with or without leucocyte reduction, on acute-phase response to surgery for total knee replacement

BACKGROUND

In patients undergoing total knee replacement (TKR) most blood loss occurs postoperatively and return of unwashed filtered shed blood (USB) from postoperative drainage may represent an alternative to allogeneic blood transfusion (ABT). We evaluated the impact of USB return, with or without leucocytes, on the acute-phase response (APR) after TKR.

PATIENTS AND METHODS

Forty-eight TKR patients, intended to receive postoperative USB, entered the study. Blood samples were obtained before and 6, 24, 72 h and 7 days after surgery, and from the USB before and after it passed through a 40-microm filter (Group F40) or a leucocyte-reduction filter (Group LRF). Haematimetric parameters, APR proteins (albumin, prealbumin, ceruloplasmin, haptoglobin, C-reactive protein), complement C3 and C4, and cytokines (IL-1beta, IL-6, IL-8, IL-10, and TNF-alpha) were measured in all samples.

RESULTS

Twenty-eight patients (Group F40=14, Group LRF=14) received a mean of 1.2 USB units, without any clinically relevant incident, and did not need additional ABT. Sixteen out of the 20 remaining patients who received neither USB nor ABT served as a control group for the postoperative APR study. All patients showed the typical postoperative APR profile and there were no significant differences between groups for APR parameters, postoperative complications, or hospital stay.

CONCLUSIONS

Postoperative blood salvage and return, with or without a LRF, after TKR does not present any clinically relevant side-effects and does not modify APR induced by surgery. These findings seem to confirm the clinical experience that postoperative USB return is safe and questions the beneficial effect of using LRF.

Reducing Allogenic Blood Transfusions during Pediatric Cranial Vault Surgical Procedures:

Almost all patients who undergo major craniosynostosis corrections receive allogenic blood transfusions. This study of intraoperative blood salvage was undertaken in an attempt to further reduce the need for blood transfusions and to enhance the safety of these complex procedures. This prospective nonrandomized series included 60 consecutive children undergoing major cranial vault remodeling, primarily for treatment of craniosynostosis (single-suture and syndromic). A single craniofacial surgeon performed all operations, using a cell-saver equipped with a 55-cc pediatric bowl. The average age of the patients in this series was 4 years (33 of 60 patients were less than 18 months of age), and the average length of the surgical procedure was 196 minutes. Fifty-three percent were primary procedures and 47 percent were secondary. The mean estimated blood loss was 356 cc (19 cc/kg, or 28.5 percent of the estimated total blood volume). An average of 110 cc of cell-saver blood (range, 5 to 900 cc), or 7.8 percent of the patient's estimated total blood volume (approximately 15 percent, accounting for hemoconcentration of the cell-saver blood), was recycled for transfusion. No statistically significant factors (primary versus secondary procedure, diagnosis, age, or weight) were identified as predictive indicators for the use of this technology. Although 59 of 60 patients received transfusions, only 18 (30 percent) received allogenic blood (average, approximately 140 cc). There were no complications associated with the use of the cell-saver device. Use of the cell-saver during major craniosynostosis repair seemed to be safe and was associated with an extremely low allogenic blood transfusion rate.

Bleeding and coagulation changes during spinal fusion surgery: a comparison of neuromuscular and idiopathic scoliosis patients

OBJECTIVE

Major blood loss is common during spinal fusion surgery. We have previously demonstrated that patients with neuromuscular scoliosis have more blood loss and greater transfusion requirement than those with idiopathic scoliosis. Our objective is to study the relationships between etiology of scoliosis, blood loss, and coagulation changes in children and adolescents undergoing spinal fusion surgery.

DESIGN

Prospective, observational study.

SETTING

University teaching hospital.

PATIENTS

A total of 25 patients, 11 with neuromuscular and 14 with idiopathic scoliosis, undergoing spinal fusion surgery.

INTERVENTIONS

Blood was obtained preoperatively, 2 and 4 hrs intraoperatively, and 2 and 24 hrs postoperatively for prothrombin time, partial thromboplastin time, thrombin time, platelet count, D-dimer, factor VII and VIII activity, thrombin-antithrombin III complex, and protein induced by vitamin K absence. Changes in coagulation over time were analyzed by repeated-measures analysis of variance. Comparisons between groups were made using independent t-tests.

RESULTS

Neuromuscular scoliosis patients had significantly greater blood loss than idiopathic scoliosis patients (median blood loss, 78% of total blood volume; range, 25-127% vs. 20%, 2-82%; p < .001). Prothrombin time increased over time in both groups and was higher in the neuromuscular than the idiopathic group both preoperatively and postoperatively (p < .05). Factor VII activity decreased over time in both groups (p < .001) and was lower in the neuromuscular than the idiopathic group during surgery (p < .05). No changes in partial thromboplastin time, thrombin time, or factor VIII activity were observed. D-dimers were present in both groups by 4 hrs intraoperatively. Protein induced by vitamin K absence was not detected in any patient.

CONCLUSIONS

Neuromuscular scoliosis patients have more blood loss during spinal fusion surgery than idiopathic scoliosis patients. The prolongation of prothrombin time and decrease in Factor VII activity suggest activation of the extrinsic coagulation pathway. Depletion of clotting factors during scoliosis surgery occurs to a greater extent in patients with underlying neuromuscular disease.