Transfusion-associated hyperkalemia

Hemostatic Evaluation of Refrigerated Whole Blood Stored 7 Days Post-Expiration

INTRODUCTION

The United States Army has shifted doctrine to focus on large-scale combat operations against peer to near-peer adversaries. Future conflicts could result in a limited supply chain, leaving medical providers with only expired blood products for treatment of hemorrhagic shock. This study evaluated quality, function, and safety metrics of whole blood stored for 1 week past regulated expiration (i.e., 35 days, in CPDA-1).

MATERIALS AND METHODS

Whole blood units (n = 6) were collected in citrate phosphate dextrose adenine-1 (CPDA-1) anticoagulant and stored refrigerated for up to 42 days. Units were sampled on days 35, 37, 39, and 42 of storage and evaluated for the following: complete blood count, blood metabolism and chemistries, clotting dynamics, and presence of bacteria.

RESULTS

The majority of evaluated parameters fell outside of normal clinical ranges beginning at day 35 of storage. At 42 days, blood pH was 6.58 ± 0.038, hemolysis was significantly increased (P = .037 vs day 35), and bacterial contamination was not evident. Glucose levels continuously dropped during extended storage. K+ was significantly increased at day 42 compared to day 35 (P = .010). A significant reduction in clot strength, factor V activity, and factor VIII activity was evident beginning at day 39 of storage.

CONCLUSIONS

Storage of whole blood out to 42 days results in a continuous decline in function, but further in vivo safety studies should be performed to determine if the benefits of expired blood outweigh the risks. Other methods to safely extend storage of whole blood that maintain hemostatic function and preserve safety should be investigated, with emphasis placed on methods that reduce potassium leak and/or hemolysis.

The compound effect of irradiation and familial pseudohyperkalemia on potassium leak from red blood cells

BACKGROUND

Familial pseudohyperkalemia (FP) is a rare asymptomatic condition characterized by an increased rate of potassium leak from red blood cells (RBC) on refrigeration. Gamma irradiation compromises RBC membrane integrity and accelerates potassium leakage. Here, we compared the effect of irradiation, applied early or late in storage, on FP versus non-FP RBC.

STUDY DESIGN

Five FP and 10 non-FP individuals from the National Institute for Health Research Cambridge BioResource, UK, and three FP and six non-FP individuals identified by Australian Red Cross Lifeblood consented to the study. Blood was collected according to standard practice in each center, held overnight at 18-24°C, leucocyte-depleted, and processed into red cell concentrates (RCC) in Saline Adenine Glucose Mannitol. On Day 1, RCC were split equally into six Red Cell Splits (RCS). Two RCS remained non-irradiated, two were irradiated on Day 1 and two were irradiated on Day 14. RBCs were tested over cold storage for quality parameters.

RESULTS

As expected, non-irradiated FP RCS had significantly higher supernatant potassium levels than controls throughout 28 days of storage (p < .001). When irradiated early, FP RCS released potassium at similar rates to control. When irradiated late, FP RCS supernatants had higher initial post-irradiation potassium concentration than controls but were similar to controls by the end of storage (14 days post-irradiation). No other parameters studied showed a significant difference between FP and control.

DISCUSSION

FP does not increase the rate of potassium leak from irradiated RBCs. Irradiation may cause a membrane defect similar to that in FP RBCs.

Early and Late-Phase 24 h Responses of Stored Red Blood Cells to Recipient-Mimicking Conditions

The 24-hour (24 h) post-transfusion survival of donor red blood cells (RBCs) is an important marker of transfusion efficacy. Nonetheless, within that period, donated RBCs may encounter challenges able to evoke rapid stress-responses. The aim of the present study was to assess the effect of exposure to plasma and body temperature upon stored RBCs under recipient-mimicking conditions in vitro from the first hours "post-transfusion" up to 24 h. For this purpose, packed RBCs from seven leukoreduced CPD/SAGM units were reconstituted with plasma of twenty-seven healthy individuals and incubated for 24 h at 37^oC. Three units were additionally used to examine stress-responses in 3-hour intervals post mixing with plasma (n = 5) until 24 h. All experiments were performed in shortly-, medium-, and long-stored RBCs. Hemolysis, redox, morphology, membrane protein binding and vesiculation parameters were assessed. Even though spontaneous hemolysis was minimal post-reconstitution, it presented a time-dependent increase. A similar time-course profile was evident for the concentration of procoagulant extracellular vesicles and the osmotic fragility (shortly-stored RBCs). On the contrary, mechanical fragility and reactive oxygen species accumulation were characterized by increases in medium-stored RBCs, evident even from the first hours in the recipient-mimicking environment. Finally, exposure to plasma resulted in rapid improvement of morphology, especially in medium-stored RBCs. Overall, some RBC properties vary significantly during the first 24 h post-mixing, at levels different from both the storage ones and the standard end-of-24 h. Such findings may be useful for understanding the performance of RBCs and their possible clinical effects -especially on susceptible recipients- during the first hours post-transfusion.

X- and gamma-irradiation have similar effects on the in vitro quality of stored red cell components

BACKGROUND

Blood components are irradiated to inactivate lymphocytes to prevent transfusion-associated graft versus host disease. As there are little data regarding the effects of X-irradiation on red blood cell components (RBCs), the in vitro quality of stored red cells (standard, pediatric, washed, and intra-uterine transfusion [IUT]) following X- or gamma-irradiation was compared.

STUDY DESIGN AND METHODS

RBCs were pooled, split, and processed to produce standard (<14 days and < 5 days post-collection), pediatric (<5 days post-collection), washed (<14 days post-collection), or IUT RBCs (<5 days post-collection). Standard RBCs were either X- or gamma-irradiated (n = 10 pairs). A further 10 replicates were prepared by pooling and splitting three matched RBCs (X-, gamma-, and non-irradiated). All other RBCs were either X- or gamma-irradiated (n = 20 pairs). Red cell indices, hemolysis, potassium release, metabolism, microparticles, ATP, and 2,3-DPG were measured pre-irradiation and 6 h, 1, 2, 3, 7, 10, and 14 days post-irradiation, depending on the component type. Data were analyzed using two-way repeated measures ANOVA.

RESULTS

There were no significant differences in any in vitro quality measurements, with the exception of marginally higher potassium release in washed, IUT, and RBCs <5 days old (p < .0001) following X-irradiation. Both irradiation types increased generation of microvesicles, particularly in components that were older at the time of irradiation or stored for longer post-irradiation.

CONCLUSION

X- and gamma-irradiation have similar effects on the in vitro quality of RBCs, indicating that either technology is suitable for blood component irradiation.

Neonatal and pediatric blood bank practice in the United States: Results from the AABB pediatric transfusion medicine subsection survey

BACKGROUND

There are limited standards guiding the selection and processing of blood components specific for neonatal and pediatric transfusions. Therefore, blood banks (BBs) and transfusion services must create their own policies and procedures.

STUDY DESIGN AND METHODS

The American Association of Blood Banks (AABB) Pediatric Transfusion Medicine Subsection Committee developed a 74-question survey to capture neonatal and pediatric BB practices in the United States.

RESULTS

Thirty-five centers completed the survey: a response rate 15.8%. Responses indicated that most carry a mixed inventory of red blood cells (RBCs); 94.2% allow more than one type of RBC product for small-volume (SV) and large-volume (LV) transfusions to neonatal and pediatric patients. Many had storage age thresholds for RBCs transfused to neonates (SV = 60%, LV = 67.7%) but not older pediatric patients. The use of Group O for nonurgent RBC transfusion in neonates was common (74.2%). Responses related to special processing of RBCs and platelets indicated that 100% RBC and platelets are leukocyte-reduced (LR) for neonates and 97% for non-neonates. Irradiation of RBCs and platelets was commonly performed for neonatal transfusion (88.6%). Providing cytomegalovirus (CMV) seronegative products, volume reduction, and washing were variable. All centers transfused single-donor apheresis platelets; 20% allowed pathogen reduction (PR). The majority of centers have strategies limiting the amount of incompatible plasma transfused; however, few titrate ABO isoagglutinins in plasma-containing products (20% for platelets and 9.1% for plasma).

CONCLUSIONS

Variability exists in BB practice for neonatal and pediatric transfusion. Future studies are needed to understand and define best BB practices in these patient populations.

Familial pseudohyperkalemia induces significantly higher levels of extracellular potassium in early storage of red cell concentrates without affecting other standard measures of quality: A case control and allele frequency study

BACKGROUND

Familial pseudohyperkalemia (FP) is characterized by an increased rate of potassium leakage in refrigerated red cells and is associated with the minor allele of the single nucleotide polymorphism rs148211042 (R723Q) in the ABCB6 gene. The study aims were to obtain the minor allele frequencies of ABCB6 variants and to measure supernatant potassium accumulation, and other red cell storage parameters, in red cell concentrates (RCC) from carriers of variant rs148211042 under standard blood bank conditions.

STUDY DESIGN

Whole blood units were collected from 6 FP individuals and 11 controls and processed into RCC in additive solution. RCC were sampled and tested over cold storage for full blood count, extracellular potassium, glucose, lactate, microvesicle release, deformability, hemolysis, pH, adenosine triphosphate, and 2,3-diphosphoglycerate.

RESULTS

Screening of genotyped cohorts identified that variant rs148211042 is present in 1 in 394 British citizens of European ancestry. FP RCC had significantly higher supernatant potassium at all time points from day 3 onwards (p < .001) and higher mean cell volume (p = .032) than controls. The initial rate of potassium release was higher in FP RCC; supernatant potassium reached 46.0 (23.8-57.6) mmol/L (mean [range]) by day 5, increasing to 68.9 (58.8-73.7) mmol/L by day 35. Other quality parameters were not significantly different between FP RCC and controls.

CONCLUSION

These data suggest that if a blood donor has FP, reducing the RCC shelf-life to 5 days may be insufficient to reduce the risk of hyperkalemia in clinical scenarios such as neonatal large volume transfusion.

Transfusion-associated hyperkalemia in pediatric population: Prevalence, risk factors, survival, infusion rate, and RBC unit features

BACKGROUND

Hyperkalemia is a rare life-threatening complication of red blood cell (RBC) transfusion. Stored RBCs leak intracellular potassium (K+) into the supernatant; irradiation potentiates the K+ leak. As the characteristics of patients and implicated RBCs have not been studied systematically, a multicenter study of transfusion-associated hyperkalemia (TAH) in the pediatric population was conducted through the AABB Pediatric Transfusion Medicine Subsection.

STUDY DESIGN

The medical records of patients <18 years old were retrospectively queried for hyperkalemia occurrence during or ≤12 h after the completion of RBC transfusion in a 1-year period. Collected data included patient demographics, diagnosis, medical history, timing of hyperkalemia and transfusion, mortality, and RBC unit characteristics.

RESULTS/FINDINGS

A total of 3777 patients received 19,649 RBC units during the study period in four facilities. TAH was found in 35 patients (0.93%) in 37 occurrences. The patient median age and weight were 1.28 years and 9.80 kg, respectively. All patients had multiple serious comorbidities. There were 79 RBC units transfused in the TAH events; 62% were irradiated, and the median age of the units was 10 days. The median total RBC volume transfused ≤12 h before TAH was 24% of patient estimated total blood volume, and the median infusion rate (IR) was19.6 ml/kg/h. Mortality rate within 1 day after the TAH event was 20%.

CONCLUSIONS

The prevalence of TAH in children was low; however, the 1-day mortality rate was 20%. Patients with multiple comorbidities may be at higher risk for TAH. The IR was higher for patients who had TAH than the IR threshold for safe transfusion.

Hypothermic storage of leukoreduced red blood cells for greater than 21 days is a safe alternative to irradiation

BACKGROUND

Irradiation of red blood cells (RBCs) inactivates residual donor T lymphocytes to prevent transfusion-associated graft-vs-host disease (TA-GVHD) but can have adverse effects on recipients and inventory management. Reported incidence of TA-GVHD is lower when leukoreduced RBCs and older blood products are transfused; therefore, the impact of leukoreduction and storage was evaluated as an alternative prevention strategy.

STUDY DESIGN AND METHODS

Effectiveness of leukoreduction filters on white blood cell (WBC) proliferation was evaluated by filtering buffy coat (BC) products and isolating residual WBCs. Additionally, leukoreduced RBCs were spiked with 5 × 10⁶ WBCs on Day 21 of hypothermic storage, then stored and processed on Days 7, 14, and 21 to obtain residual WBCs to investigate the impact of hypothermic storage on their viability and proliferative ability. Viability of residual WBCs was assessed by staining with annexin V and an antibody cocktail for flow cytometry analysis. Proliferative ability was assessed by placing carboxyfluorescein diacetate succinimidyl ester-labeled residual WBCs into culture for 6 days with phytohemagglutinin before flow cytometry assessment.

RESULTS

Filtration of BC units depleted WBCs, particularly T lymphocytes, to 0.001% ± 0.003% cells/unit, although proliferative activity remained consistent with prefiltration levels of WBCs. WBCs in stored RBCs remained viable even on Day 21 of storage; however, the proliferative activity decreased to 0.24% ± 0.41%.

CONCLUSIONS

Hypothermic storage of RBCs for 21 days or more is sufficient to inactivate T lymphocytes, which may help prevent TA-GVHD when irradiated RBCs are not available.

Transfusion-Associated Hyperkalemic Cardiac Arrest in Neonatal, Infant, and Pediatric Patients

Red blood cell (RBC) transfusions are a life-saving intervention, with nearly 14 million RBC units transfused in the United States each year. However, the safety and efficacy of this procedure can be influenced by variations in the collection, processing, and administration of RBCs. Procedures or manipulations that increase potassium (K⁺) levels in stored blood products can also predispose patients to hyperkalemia and transfusion-associated hyperkalemic cardiac arrest (TAHCA). In this mini review, we aimed to provide a brief overview of blood storage, the red cell storage lesion, and variables that increase extracellular [K⁺]. We also summarize cases of TAHCA and identify potential mitigation strategies. Hyperkalemia and cardiac arrhythmias can occur in pediatric patients when RBCs are transfused quickly, delivered directly to the heart without time for electrolyte equilibration, or accumulate extracellular K⁺ due to storage time or irradiation. Advances in blood banking have improved the availability and quality of RBCs, yet, some patient populations are sensitive to transfusion-associated hyperkalemia. Future research studies should further investigate potential mitigation strategies to reduce the risk of TAHCA, which may include using fresh RBCs, reducing storage time after irradiation, transfusing at slower rates, implementing manipulations that wash or remove excess extracellular K⁺, and implementing restrictive transfusion strategies.

Ovine red cell concentrates for transfusion research - is the storage lesion comparable to human red cell concentrates?

BACKGROUND AND OBJECTIVES

Sheep are increasingly being used as a large in vivo animal model of blood transfusion because they provide several advantages over small animals. Understanding the effects of storage duration on ovine (ov) red cell concentrates (RCCs) and how these changes compare with stored human (hu) RCCs is necessary to facilitate clinical translation of research findings.

MATERIALS AND METHODS

OvRCCs (n = 5) collected and processed in standard human blood collection packs, and equivalent huRCCs provided by Australian Red Cross Lifeblood (n = 5), were stored at 2-6°C for 42 days, with samples collected weekly. Haemolysis index was determined by measuring supernatant haemoglobin concentration. Biochemical parameters were evaluated using a blood gas analyser. Energy metabolites and biologically active lipids were measured using commercial assays. Osmotic fragility was determined by lysis in various saline concentrations. Extracellular vesicles were characterized by nanoparticle tracking analysis.

RESULTS

Ovine red blood cells (RBCs) are double in number, smaller in size and more fragile than human RBCs. Haematological values were unchanged throughout storage. In contrast, biochemical and metabolic values, and haemolysis index in three of the five ovRCCs exceeded huRCCs licensing criteria by day 42. Accumulation of extracellular vesicles and biologically active lipids was comparable between huRCCs and ovRCCs.

CONCLUSION

This study documents similarities and differences in the storage lesion of ovRCCs and huRCCs. This new information will guide the design of ovine transfusion models to enhance translation of findings to human transfusion settings.

Impact of different syringe pumps on red cells during paediatric simulated transfusion

BACKGROUND

Critically ill patients frequently need blood transfusions. For safety, blood must be delivered via syringe infusion pumps, yet this can cause red cell damage and increase the rate of haemolysis.

AIMS AND OBJECTIVES

To evaluate biochemical and haemolytic markers of red blood cells transfused in three different types of syringe infusion pumps at two different infusion rates (10 and 100 mL/h).

DESIGN AND METHODS

A lab-based study using aliquots of 16 red blood cell bags was undertaken. Haemolysis markers (total haemoglobin [g/dL], haematocrit [%], free haemoglobin [g/dL], potassium [mmol/L], lactate dehydrogenase [U/L], osmolality [mOsm/kg], pH, degree of haemolysis [%]) were measured before and after red blood cell infusion and exposure. Three different syringe infusion pumps brands (A, B, and C) were compared at two different infusion rates (10 and 100 mL/h).

RESULTS

Total haemoglobin fell significantly in all red blood cell units during manipulation (pre-infusion: 26.44 ± 5.74; post-exposure: 22.62 ± 4.00; P = .026). The degree of haemolysis significantly increased by 40% after manipulation of the red blood cells. Syringe infusion pump A caused a 3-fold increase in potassium levels (3.78 ± 6.10) when compared with B (-0.14 ± 1.46) and C (1.63 ± 1.98) (P = .015). This pump also produced the worst changes, with an increase in free haemoglobin (0.05 ± 0.05; P = .038) and more haemolysis (0.08 ± 0.07; P = .033). There were significant differences and an increase in the degree of haemolysis (P = .004) at the infusion rate of 100 mL/h.

CONCLUSIONS

Syringe infusion pumps may cause significant red blood cell damage during infusion, with increases in free haemoglobin, potassium, and the degree of haemolysis. Some pump types, with a cassette mechanism, caused more damage.

RELEVANCE TO CLINICAL PRACTICE

In many intensive care units, bedside nurses are able to consider infusion pump choice, and understanding the impact of different pump types on red blood cells during a transfusion provides the nurses with more information to enhance decision-making and improve the quality of the transfusion.

Double-filtered leukoreduction as a method for risk reduction of transfusion-associated graft-versus-host disease

Background

Transfusion-associated graft-versus-host disease (TA-GvHD) is caused by leukocytes, specifically T cells within a transfused blood product. Currently, the prevention of transfusion-associated graft-versus-host disease is performed by irradiation of blood products. With a sufficient reduction of leukocytes, the risk for TA-GvHD can be decreased. With consistent advances in current state-of-the-art blood filters, we herein propose that double filtration can sufficiently reduce leukocytes to reduce the risk for TA-GvHD.

Materials

Thirty RBC concentrates were filtered with leukocyte filters, followed by storage at 1–6 ^oC for 72 hours, and then a second filtration was performed. Residual leukocytes in the double-filtered RBC units (n = 30) were assessed with flow cytometric methods, and an additional assay with isolated peripheral blood mononuclear cells (PBMCs) (n = 6) was done by both flow cytometric methods and an automated hematology analyzer. Quality of the RBCs after filtration was evaluated by hematological and biochemical tests. In vitro T cell expansion was performed using anti-CD3/CD28-coated Dynabeads or anti-CD3 (OKT3). In vivo experiment for GvHD was performed by using NOD.Cg-Prkdc^scid Il2rg^tm1Wjl/SzJ (NSG) mice.

Results

Double-filtered blood products showed residual leukocyte levels below detection limits, which calculated to be below 1200–2500 cells per blood unit. In vitro expansion rate of T cells showed that 6x10³ and 1x10³ cell-seeded specimens showed 60.8±10.6 fold and 10.2±9.7-fold expansion, respectively. Cell expansion was not sufficiently observed in wells planted with 1x10² or 10 cells. In vivo experiments showed that mice injected with 1x10⁵ or more cells cause fatal GvHD. GvHD induced inflammation was observed in mice injected with 1x10⁴ or more cells. No evidence of GvHD was found in mice injected with 10³ cells.

Conclusions

Our study suggests that additional removal of contaminating lymphocytes by a second leukodepletion step may further reduce the risk for TA-GvHD.

Serial measurement of electrolyte and citrate concentrations in blood-primed continuous hemodialysis circuits during closed-circuit dialysis

BACKGROUND

For continuous renal replacement therapy in small infants, due to the large extracorporeal volume involved, blood priming can be necessary to prevent hypotension and hemodilution. Because packed red blood cells (RBCs) have high levels of potassium and citrate, closed-circuit dialysis is often performed. We assessed the metrics of closed-circuit dialysis and serial citrate concentration changes.

METHODS

We performed dialysis of closed circuits primed with expired human packed RBC solution and 5% albumin. Blood and dialysate flow rates were 70 and 33.3 mL/min, respectively. The extracorporeal volume was 70 mL. We measured pH, electrolytes, and citrate in the closed circuit every 3 min for 15 min. We also assessed the adequacy of closed-circuit dialysis using the formula: [dialysate flow rate (mL/min) × time of dialysis (min)]/extracorporeal volume (mL) and we assessed the correlation between citrate and ionized calcium concentrations.

RESULTS

To reach normal concentrations of sodium, potassium, and chloride, 2.4 times as much dialysate fluid as extracorporeal volume was needed. In contrast, for ionized calcium, bicarbonate, and citrate, 3.8 times as much dialysate fluid as extracorporeal volume was required. By simple linear regression analysis, the concentration of citrate was significantly correlated with that of ionized calcium.

CONCLUSIONS

For closed-circuit dialysis using an RBC solution, the formula [dialysate flow rate (mL/min) × time of dialysis (min)]/extracorporeal volume (mL) would be a better parameter to estimate efficacy, compared with other metrics. Additionally, the citrate concentration can be readily estimated from the ionized calcium concentration during closed-circuit dialysis.

Storage time of red blood cells among ICU patients with septic shock

BACKGROUND

We aimed to describe the exposure to blood transfusions and mortality among patients with septic shock.

METHODS

We did a retrospective cohort study of two cohorts-patients with septic shock registered in a Danish ICU database (2008-2010) and patients from the Transfusion Requirements in Septic Shock (TRISS) trial (2011-2013). We extracted information on blood transfusions issued to all patients. We investigated the number of patients receiving very fresh blood (less than 7 days), very old blood (more than 24 days) and blood with a mixture of storage time.

RESULTS

In the Danish cohort, 1637 patients were included of whom 1394 (85%) received 20,239 blood units from 14 days prior the ICU admission to 90 days after; 33% were transfused before, 77% in the ICU and 36% after ICU. The exposure to exclusively very fresh or very old blood was 3% and 4%, respectively. In the TRISS cohort, 77% of the 937 patients received 5047 RBC units; 3% received exclusively very fresh and 13% very old blood. The point estimate of mortality was higher among patients receiving large amounts of exclusively very fresh and very old blood, but the number of patients were very small.

CONCLUSIONS

Patients with septic shock were transfused both before and after ICU. Exposure to blood of less than 7 days or more than 24 days old were limited. We were not able to detect higher mortality among the limited number of patients with septic shock transfused with very fresh or very old blood.

Safety Profile of Lumbosacropelvic Fixation in Patients Aged 60 Years or Older: Comparison Between S2-Alar-Iliac Screws and Conventional Iliac Screws

STUDY DESIGN

This is a retrospective study.

OBJECTIVE

To report the safety profile of S2-alar-iliac (S2AI) in patients over 60, comparing S2AI screws with iliac screws (ISs).

SUMMARY OF BACKGROUND DATA

The surgical management involving the lumbosacropelvic spine remains a challenge due to high mechanical demand and risk of pseudarthrosis. Previous articles showed lower rates of complications in patients receiving S2AI screws than ISs; however, none of them have focused on patients aged over 60 who may harbor significant comorbidities and thus require more meticulous perioperative management, given these invasive and lengthy procedures.

MATERIALS AND METHODS

Retrospective review of clinical records from 2010 to 2015 identified 60 patients undergoing lumbosacropelvic fixation (17 patients with ISs and 43 patients with S2AI screws) who satisfied the following criteria: (1) patients aged over 60 years old and (2) patients with >1-year follow-up periods. Rates of complications such as unplanned reoperation and cardiorespiratory complications were collected and statistically analyzed.

RESULTS

Baseline characteristics such as age, sex, and comorbidities were similar in both groups. The S2AI group had lower rates of reoperation (18.6% vs. 47.4%; P=0.02), surgical site infection (2.3% vs. 29.4%; P=0.006), wound dehiscence (2.3% vs. 29.4%; P=0.006), and postoperative anemia (7.0% vs. 29.4%; P=0.03) and had lower total volume of estimated blood loss (EBL) (mL) (1846.4 vs. 2721.2; P=0.02) and transfused red blood cell units (7.2 vs. 4.7; P=0.04) than the IS group, while rates of L5-S1 pseudarthrosis and other cardiorespiratory complications were similar in both groups. In multivariate analysis, operative time, body mass index, and use of S2AI screws over ISs were independent predictors of EBL.

CONCLUSIONS

Use of S2AI screws over ISs in patients aged over 60 was associated with lower rates of reoperation, surgical site infection, wound dehiscence, and lower volume of EBL and red blood cell transfusion and is a viable surgical option.

Centrifugation-free washing: A novel approach for removing immunoglobulin A from stored red blood cells

Washed red blood cells (RBCs) are indicated for immunoglobulin A (IgA) deficient recipients. Centrifugation-based cell processors commonly used by hospital blood banks cannot consistently reduce IgA below the recommended levels, hence double washing is frequently required. Here, we describe a prototype of a simple, portable, disposable system capable of washing stored RBCs without centrifugation, while reducing IgA below 0.05 mg/dL in a single run. Samples from RBC units (n = 8, leukoreduced, 4-6 weeks storage duration) were diluted with normal saline to a hematocrit of 10%, and then washed using either the prototype washing system, or via conventional centrifugation. The efficiency of the two washing methods was quantified and compared by measuring several key in vitro quality metrics. The prototype of the washing system was able to process stored RBCs at a rate of 300 mL/hour, producing a suspension of washed RBCs with 43 ± 3% hematocrit and 86 ± 7% cell recovery. Overall, the two washing methods performed similarly for most measured parameters, lowering the concentration of free hemoglobin by >4-fold and total free protein by >10-fold. Importantly, the new washing system reduced the IgA level to 0.02 ± 0.01 mg/mL, a concentration 5-fold lower than that produced by conventional centrifugation. This proof-of-concept study showed that centrifugation may be unnecessary for washing stored RBCs. A simple, disposable, centrifugation-free washing system could be particularly useful in smaller medical facilities and resource limited settings that may lack access to centrifugation-based cell processors.

Intraoperative management of liver transplant recipients having severe renal dysfunction: results of 42 cases

Purpose

Whereas continuous renal replacement therapy (CRRT) has been utilized during liver transplantation (LT), there was a lack of evidence to support this practice. We investigated the adverse events at the perioperative periods in recipients of LT who received preoperative CRRT without intraoperative CRRT.

Methods

We retrospectively reviewed medical records of adult patients (age ≥ 18 years) who received LT between December 2009 and May 2015. Perioperative data were collected from the recipients, who received preoperative CRRT until immediately before LT, because of refractory renal dysfunction.

Results

Of 706 recipients, 42 recipients received preoperative CRRT. The mean (standard deviation) Model for end-stage liver disease score were 49.6 (13.4). Twenty-six point two percent (26.2%) of recipients experienced the serum potassium > 4.5 mEq/L before reperfusion and treated with regular insulin. Thirty-eight point one percent (38.1%) of recipients were managed with sodium bicarbonate because of acidosis (base excess < −10 mEq/L throughout LT). All patients finished their operations without medically uncontrolled complications such as severe hyperkalemia (serum potassium > 5.5 mEq/L), refractory acidosis, or critical arrhythmias. Mortality was 19% at 30 day and 33.3% at 1 year.

Conclusion

Although intraoperative CRRT was not used in recipients with severe preoperative renal dysfunction, LT was safely performed. Our experience raises a question about the need for intraoperative CRRT.

Transfusion-associated hazards: A revisit of their presentation

As a therapy or a support to other therapies, despite being largely beneficial to patients in general, transfusion it is not devoid of some risks. In a moderate number of cases, patients may manifest adverse reactions, otherwise referred to as transfusion-associated hazards (TAHs). The latest French 2016 haemovigilance report indicates that 93% of TAHs are minor (grade 1), 5.5% are moderate (grade 2) and 1.6% are severe (grade 3), with only five deaths (grade 4) being attributed to transfusion with relative certainty (imputability of level [or grade] 1 to 3). Health-care providers need to be well aware of the benefits and potential risks (to best evaluate and discuss the benefit-risk ratio), how to prevent TAHs, the overall costs and the availability of alternative therapeutic options. In high-income countries, most blood establishments (BEs) and hospital blood banks (HBBs) have developed tools for reporting and analysing at least severe transfusion reactions. With nearly two decades of haemovigilance, transfusion reaction databases should be quite informative, though there are four main caveats that prevent it from being fully efficient: (ai) reporting is mainly declarative and is thus barely exhaustive even in countries where it is mandatory by law; (aii) it is often difficult to differentiate between the different complications related to transfusion, diseases, comorbidities and other types of therapies in patients suffering from debilitating conditions; (aiii) there is a lack of consistency in the definitions used to describe and report some transfusion reactions, their severity and their likelihood of being related to transfusion; and (aiv) it is difficult to assess the imputability of a particular BC given to a patient who has previously received many BCs over a relatively short period of time. When compiling all available information published so far, it appears that TAHs can be analysed using different approaches: (bi) their pathophysiological nature; (bii) their severity; (biii) the onset scheme; (biv) a quality assessment (preventable or non-preventable); (bv) their impact on ongoing therapy. Moreover, TAHs can be reported either in a non-integrative or in an integrative way; in the latter case, presentation may also differ when issued by a blood establishment or a treating ward. At some point, a recapitulative document would be useful to gain a better understanding of TAHs in order to decrease their occurrence and severity and allow decision makers to determine action plans: this is what this review attempts to make. This review attempts to merge the different aspects, with a focus on the hospital side, i.e., how the most frequent TAHs can be avoided or mitigated.

Safety, Efficacy, and Timeliness of Intravenous Potassium Chloride Replacement Protocols in a Pediatric Cardiothoracic Intensive Care Unit

OBJECTIVE

Hypokalemia in children following cardiac surgery occurs frequently, placing them at risk of life-threatening arrhythmias. However, renal insufficiency after cardiopulmonary bypass warrants careful administration of potassium (K⁺). Two different nurse-driven protocols (high dose and tiered dosing) were implemented to identify an optimal K⁺ replacement regimen, compared to an historical low-dose protocol. Our objective was to evaluate the safety, efficacy, and timeliness of these protocols.

DESIGN

A retrospective cohort review of pediatric patients placed on intravenous K⁺ replacement protocols over 1 year was used to determine efficacy and safety of the protocols. A prospective single-blinded review of K⁺ repletion was used to determine timeliness.

PATIENTS

Pediatric patients with congenital or acquired cardiac disease.

SETTING

Twenty-four-bed cardiothoracic intensive care unit in a tertiary children's hospital.

INTERVENTIONS

Efficacy was defined as fewer supplemental potassium chloride (KCl) doses, as well as a higher protocol to total doses ratio per patient. Safety was defined as a lower percentage of serum K⁺ levels ≥4.8 mEq/L after a dose of KCl. Between-group differences were assessed by nonparametric univariate analysis.

RESULTS

There were 138 patients with a median age of 3.0 (interquartile range: 0.23-10.0) months. The incidence of K⁺ levels ≥4.8 mEq/L after a protocol dose was higher in the high-dose protocol versus the tiered-dosing protocol but not different between the low-dose and tiered-dosing protocols (high dose = 2.2% vs tiered dosing = 0.5%, P = .05). The ratio of protocol doses to total doses per patient was lower in the low-dose protocol compared to the tiered-dosing protocol (P < .05). Protocol doses were administered 45 minutes faster (P < .001).

CONCLUSION

The tiered-dosed, nurse-driven K⁺ replacement protocol was associated with decreased supplemental K⁺ doses without increased risk of hyperkalemia, administering doses faster than individually ordered doses; the protocol was effective, safe, and timely in the treatment of hypokalemia in pediatric patients after cardiac surgery.

Metabolic Linkage and Correlations to Storage Capacity in Erythrocytes from Glucose 6-Phosphate Dehydrogenase-Deficient Donors

Objective

In glucose 6-phosphate dehydrogenase (G6PD) deficiency, decreased NADPH regeneration in the pentose phosphate pathway and subnormal levels of reduced glutathione result in insufficient antioxidant defense, increased susceptibility of red blood cells (RBCs) to oxidative stress, and acute hemolysis following exposure to pro-oxidant drugs and infections. Despite the fact that redox disequilibrium is a prominent feature of RBC storage lesion, it has been reported that the G6PD-deficient RBCs store well, at least in respect to energy metabolism, but their overall metabolic phenotypes and molecular linkages to the storability profile are scarcely investigated.

Methods

We performed UHPLC-MS metabolomics analyses of weekly sampled RBC concentrates from G6PD sufficient and deficient donors, stored in citrate phosphate dextrose/saline adenine glucose mannitol from day 0 to storage day 42, followed by statistical and bioinformatics integration of the data.

Results

Other than previously reported alterations in glycolysis, metabolomics analyses revealed bioactive lipids, free fatty acids, bile acids, amino acids, and purines as top variables discriminating RBC concentrates for G6PD-deficient donors. Two-way ANOVA showed significant changes in the storage-dependent variation in fumarate, one-carbon, and sulfur metabolism, glutathione homeostasis, and antioxidant defense (including urate) components in G6PD-deficient vs. sufficient donors. The levels of free fatty acids and their oxidized derivatives, as well as those of membrane-associated plasticizers were significantly lower in G6PD-deficient units in comparison to controls. By using the strongest correlations between in vivo and ex vivo metabolic and physiological parameters, consecutively present throughout the storage period, several interactomes were produced that revealed an interesting interplay between redox, energy, and hemolysis variables, which may be further associated with donor-specific differences in the post-transfusion performance of G6PD-deficient RBCs.

Conclusion

The metabolic phenotypes of G6PD-deficient donors recapitulate the basic storage lesion profile that leads to loss of metabolic linkage and rewiring. Donor-related issues affect the storability of RBCs even in the narrow context of this donor subgroup in a way likely relevant to transfusion medicine.

Successful Resuscitation in a Model of Asphyxia and Hemorrhage to Test Different Volume Resuscitation Strategies. A Study in Newborn Piglets After Transition

Background: Evidence for recommendations on the use of volume expansion during cardiopulmonary resuscitation in newborn infants is limited. Objectives: To develop a newborn piglet model with asphyxia, hemorrhage, and cardiac arrest to test different volume resuscitation on return of spontaneous circulation (ROSC). We hypothesized that immediate red cell transfusion reduces time to ROSC as compared to the use of an isotonic crystalloid fluid. Methods: Forty-four anaesthetized and intubated newborn piglets [age 32 h (12-44 h), weight 1,220 g (1,060-1,495g), Median (IQR)] were exposed to hypoxia and blood loss until asystole occurred. At this point they were randomized into two groups: (1) Crystalloid group: receiving isotonic sodium chloride (n = 22). (2) Early transfusion group: receiving blood transfusion (n = 22). In all other ways the piglets were resuscitated according to ILCOR 2015 guidelines [including respiratory support, chest compressions (CC) and epinephrine use]. One hour after ROSC piglets from the crystalloid group were randomized in two sub-groups: late blood transfusion and infusion of isotonic sodium chloride to investigate the effects of a late transfusion on hemodynamic parameters. Results: All animals achieved ROSC. Comparing the crystalloid to early blood transfusion group blood loss was 30.7 ml/kg (22.3-39.6 ml/kg) vs. 34.6 ml/kg (25.2-44.7 ml/kg), Median (IQR). Eleven subjects did not receive volume expansion as ROSC occurred rapidly. Thirty-three animals received volume expansion (16 vs. 17 in the crystalloid vs. early transfusion group). 14.1% vs. 10.5% of previously extracted blood volume in the crystalloid vs. early transfusion group was infused before ROSC. There was no significant difference in time to ROSC between groups [crystalloid group: 164 s (129-198 s), early transfusion group: 163 s (162-199 s), Median (IQR)] with no difference in epinephrine use. Conclusions: Early blood transfusion compared to crystalloid did not reduce time to ROSC, although our model included only a moderate degree of hemorrhage and ROSC occurred early in 11 subjects before any volume resuscitation occurred.

Safety of potassium-bearing citrate in patients with renal transplantation: A case report

RATIONALE

Urinary lithiasis is one of severe postoperative complications in patients undergoing renal transplantation, possibly leading to anuria, urinary infection, or even acute renal failure. Potassium sodium hydrogen citrate (PSHC), a potassium-bearing citrate, is commonly prescribed to prevent stone formation.

PATIENT CONCERNS

A 25-year-old man (patient 1) and a 31-year-old man (patient 2) receiving renal transplantation for end-stage renal disease (ESRD) were enrolled in this study. They were given 10 g/day of PSHC granules from the ninth day to the 17th day after surgery. Patient 1 presented chest tightness, nausea, muscle weakness, and ascending paralysis on the 10th day. Patient 2 presented weak waves on EGG on the 17th day. Moreover, their serum potassium concentrations (SPCs) were 7.67 and 6.05 mmol/L, respectively.

DIAGNOSIS

Acute hyperkalemia.

INTERVENTIONS

Hemo-filtration was performed for patient 1, while patient 2 received 10% calcium gluconate 10 mL, 5% NaHCO3 125 mL, and 10% glucose 500 mL with the addition of 10 units of insulin through intravenous drip.

OUTCOMES

Their SPCs dropped to the normal range.

LESSONS

Physicians should pay close attentions to potential risks caused by PSHC, and monitor the SPCs to minimize the occurrence of hyperkalemia.

Biochemical evaluation of storage lesion in canine packed erythrocytes

OBJECTIVES

To describe the biochemical changes - also known as the storage lesion - that occur in canine packed red blood cells during ex vivo storage.

MATERIALS AND METHODS

Ten 125-mL units of non-leuco-reduced packed red blood cells in citrate phosphate dextrose adenine were obtained from a commercial blood bank within 24 hours of donation. Samples were aseptically collected on days 1, 4, 7, 14, 28, 35 and 42 for measurement of sodium, potassium, chloride, lactate, glucose, pH and ammonia concentrations. All units were cultured on day 42. Friedman's repeated measures test with Dunn's multiple comparison test was used for non-parametric data. A repeated-measures analysis of variance with Tukey's multiple comparison test was used for parametric data. Alpha was set to 0·05.

RESULTS

All analytes changed significantly during storage. The mean ammonia on day 1 (58·14 g/dL) was significantly lower (P<0·05) than those on days 28 (1266 g/dL), 35 (1668 g/dL) and 42 (1860 g/dL). A significant increase in median lactate concentration over time was also observed, with day 1 (4·385 mmol/L) being significantly less (P<0·05) than days 14 (19·82 mmol/L), 21 (22·81 mmol/L), 35 (20·31 mmol/L) and 42 (20·81 mmol/L). Median pH was significantly decreased after day 7. All bacterial cultures were negative.

CLINICAL SIGNIFICANCE

Many biochemical alterations occur in stored canine packed red blood cells, although further studies are required to determine their clinical importance.

Effect of transfusion of washed red blood cells on serumpotassium level in hemodialysis patients

BACKGROUND/AIM

This study aimed to compare washed red blood cell (WRBC) transfusion versus nonwashed RBC (NWRBC) transfusion in terms of posttransfusion potassium levels in dialysis patients on a day when the patient did not receive dialysis.

MATERIALS AND METHODS

The patients were randomly assigned into two groups, i.e. those receiving WRBCs (n = 21) and those receiving NWRBCs (n = 17). Both groups received one unit of RBCs. Serum potassium and sodium levels were measured before and at the 1st, 2nd, 3rd, 4th, and 6th hours after transfusion.

RESULTS

In the WRBC group, the changes in the serum potassium levels at the 3rd, 4th, and 6th hours after transfusion were significant compared with pretransfusion levels. In the serum potassium levels mean decreases by 0.38 ± 0.57 mEq/L at the 3rd hour (P = 0.006), by 0.32 ± 0.47 mEq/L at the 4th hour (P = 0.005), and by 0.32 ± 0.51 mEq/L at the 6th hour (P = 0.009) after transfusion were significant compared with the pretransfusion levels.

CONCLUSION

Although nonwashed RBC transfusion does not change serum potassium levels, washed RBC transfusion significantly reduces serum potassium levels. Washed RBC transfusion is considered to be safer in hemodialysis patients with hyperkalemia and anemia.

Severe hyperkalemia following blood transfusions: Is there a link?

Patients with gastrointestinal bleeding often require large volume blood transfusion. Among the various side effects of blood transfusion, the increase of potassium levels is a serious one which is often overlooked. We report a case of severe hyperkalemia in a patient with gastric bleeding after large volume transfusion of packed red blood cells. The patient had hyperkalemia at baseline associated with his receiving medication as well as acute renal failure following hypovolemia. The baseline hyperkalemia was further aggravated after massive transfusions of packed red blood cells in a short period of time. The associated pathogenetic mechanisms resulting in the increase of potassium levels are presented. A number of risk factors which increase the risk of hyperkalemia after blood transfusion are discussed. Moreover, appropriate management strategies for the prevention of blood transfusion associated hyperkalemia are also presented. Physicians should always keep in mind the possibility of hyperkalemia in cases of blood transfusion.

Quality Assessment of Established and Emerging Blood Components for Transfusion

Blood is donated either as whole blood, with subsequent component processing, or through the use of apheresis devices that extract one or more components and return the rest of the donation to the donor. Blood component therapy supplanted whole blood transfusion in industrialized countries in the middle of the twentieth century and remains the standard of care for the majority of patients receiving a transfusion. Traditionally, blood has been processed into three main blood products: red blood cell concentrates; platelet concentrates; and transfusable plasma. Ensuring that these products are of high quality and that they deliver their intended benefits to patients throughout their shelf-life is a complex task. Further complexity has been added with the development of products stored under nonstandard conditions or subjected to additional manufacturing steps (e.g., cryopreserved platelets, irradiated red cells, and lyophilized plasma). Here we review established and emerging methodologies for assessing blood product quality and address controversies and uncertainties in this thriving and active field of investigation.

Biochemical evaluation of the effects of storage on feline erythrocytes

OBJECTIVE

To describe the biochemical changes that occur during storage of feline packed red blood cells.

METHODS

Feline packed red blood cells were obtained from the manufacturer via overnight delivery immediately following collection. Bag spikes were placed using aseptic technique and samples were drawn on days 1, 4, 7, 14, 21, 28 and 35. Sodium, potassium, chloride, glucose, lactate, pH and ammonia were measured at each time point. Aerobic and anaerobic bacterial cultures were submitted following collection on day 35.

RESULTS

There were statistically significant increases in the median concentrations of lactate and ammonia within the first 2 weeks of storage to a concentration of 12·38 mmol/L and 447·96 µmol/L, respectively. Glucose concentrations decreased significantly by day 28 to a mean of 1·86 mmol/L. Median sodium and chloride concentrations increased throughout the course of storage to a concentration of 158·20 and 131·00 mmol/L, respectively. Mean potassium concentrations decreased to a concentration of 2·40 mmol/L.

CLINICAL SIGNIFICANCE

These results show that biochemical derangements within feline packed red blood cells are progressive, with some alterations, such as lactate and ammonia, occurring early within the storage periods, while others, including glucose and electrolytes, are slower to develop. Additional prospective research evaluating the clinical effects of these biochemical alterations is required.

Infusion pumps and red blood cell damage in transfusion therapy: an integrative revision of the academic literature

Objectives:

to obtain information from scientific literature concerning infusion pumps used in administering erythrocyte (red blood cells) and to evaluate the implications in the practical use of this equipment by nurses when conducting transfusions.

Method:

an integrative revision of the following scientific databases: Pubmed/Medline, Scopus, the Virtual Library for Health, SciELO, Web of Science and Cochrane. The following descriptors were used: "infusion pumps", "blood transfusion", "transfused erythrocyte" and "hemolyis". There were no restrictions on the scope of the initial data and it was finalized in December 2014. 17 articles were identified in accordance with the inclusion and exclusion criteria.

Results:

all of the publications included in the studies were experimental in vitro and covered the use of infusion pumps in transfusion therapy. A summary of the data was presented in a synoptic chart and an analysis of it generated the following categories: cellular damage and the infusion mechanism.

Conclusion:

infusion pumps can be harmful to erythrocytes based on the infusion mechanism that is used, as the linear peristaltic pump is more likely to cause hemolysis. Cellular damage is related to the plasmatic liberation of markers that largely dominate free hemoglobin and potassium. We reiterate the need for further research and technological investments to guide the development of protocols that promote safe practices and that can contribute to future clinical studies.

The pre-operative levels of haemoglobin in the blood can be used to predict the risk of allogenic blood transfusion after total knee arthroplasty

Aims

The pre-operative level of haemoglobin is the strongest predictor of the peri-operative requirement for blood transfusion after total knee arthroplasty (TKA). There are, however, no studies reporting a value that could be considered to be appropriate pre-operatively. This study aimed to identify threshold pre-operative levels of haemoglobin that would predict the requirement for blood transfusion in patients who undergo TKA.

Patients and Methods

Analysis of receiver operator characteristic (ROC) curves of 2284 consecutive patients undergoing unilateral TKA was used to determine gender specific thresholds predicting peri-operative transfusion with the highest combined sensitivity and specificity (area under ROC curve 0.79 for males; 0.78 for females).

Results

Threshold levels of 13.75 g/dl for males and 12.75 g/dl for females were identified. The rates of transfusion in males and females, respectively above these levels were 3.37% and 7.11%, while below these levels, they were 16.13% and 28.17%. Pre-operative anaemia increased the rate of transfusion by 6.38 times in males and 6.27 times in females. Blood transfusion was associated with an increased incidence of early post-operative confusion (odds ratio (OR) = 3.44), cardiac arrhythmia (OR = 5.90), urinary catheterisation (OR = 1.60), the incidence of deep infection (OR = 4.03) and mortality (OR = 2.35) one year post-operatively, and increased length of stay (eight days vs six days, p < 0.001).

Conclusion

Uncorrected low pre-operative levels of haemoglobin put patients at potentially modifiable risk and attempts should be made to correct this before TKA. Target thresholds for the levels of haemoglobin pre-operatively in males and females are proposed. Take home message: Low pre-operative haemoglobin levels put patients at unnecessary risk and should be corrected prior to surgery. Cite this article: Bone Joint J 2016;98-B:490–7.

Modifications to Blood Components: When to Use them and What is the Evidence?

Blood component modifications can be performed by the hospital blood bank for select clinical indications. In general, modification of blood components increases costs and may delay availability of the blood component because of the additional time required for some modification steps. However, the benefit of blood product modification may outweigh these concerns. Common modifications include leukoreduction, irradiation, volume reduction, splitting, and washing. Modification availability and selection practice may vary from hospital to hospital. In this article, available blood component modifications are described along with the benefits, drawbacks, and specific clinical indications supporting their use.

Transfusion of irradiated red blood cell units with a potassium adsorption filter: A randomized controlled trial

BACKGROUND

The irradiation of red blood cells (RBCs) causes damage of the RBC membrane with increased potassium (K) leak during storage compared with nonirradiated RBC units of similar age. A previous in vitro study showed a mean reduction of K of 94 ± 5% with a potassium adsorption filter (PAF).

STUDY DESIGN AND METHODS

A prospective, single-center, nonblinded, randomized controlled trial (RCT) was designed to evaluate the safety and efficacy of transfusing irradiated RBC units with the PAF. Patients 18 years of age or older who received irradiated RBC units due to chemotherapy-induced anemia were randomly assigned to receive irradiated RBC units with the PAF (PAF group) or with the standard blood infusion set (control group). Primary outcome measures were safety and efficacy of the PAF (absolute change in hemoglobin [Hb] and K, respectively, in patient's blood values after transfusing the irradiated RBC units with or without the PAF).

RESULTS

A total of 63 irradiated RBC units were transfused to 17 patients in the control group, and a total of 56 irradiated RBC units were transfused to 13 patients in the PAF group. The absolute change of Hb (9.3 ± 6.3 g/L vs. 8.1 ± 5.8 g/L; p = 0.3) and the absolute change of K (-0.01 ± 0.4 mmol/L vs. -0.01 ± 0.3 mmol/L; p = 0.2) were comparable between the two groups of the trial.

CONCLUSION

The transfusion of 1 irradiated RBC unit with the PAF was as safe and efficacious as the transfusion of 1 irradiated RBC unit with the standard blood infusion set in patients with chemotherapy-induced anemia.

Hemolysis of irradiated leukoreduced red blood cells during rapid warming: An in vitro experimental study

Background

Although water chambers are often used as surrogate blood-warming devices to facilitate rapid warming of red blood cells (RBCs), these cells may be damaged if overheated. Moreover, filtered and irradiated RBCs may be damaged during the warming process, resulting in excessive hemolysis and extracellular potassium release.

Methods

Using hand-held syringes, each unit of irradiated and leukocyte-filtered RBCs was rapidly passed through a water chamber set to different temperatures (baseline before blood warming, 50℃, 60℃, and 70℃). The resulting plasma potassium and free hemoglobin levels were then measured.

Results

Warming RBCs to 60℃ and 70℃ induced significant increases in free hemoglobin (median [interquartile ranges] = 60.5 mg/dl [34.9–101.4] and 570.2 mg/dl [115.6–2289.7], respectively). Potassium levels after warming to 70℃ (31.4 ± 7.6 mEq/L) were significantly higher compared with baseline (29.7 ± 7.1 mEq/L; P = 0.029). Potassium levels were significantly correlated with storage duration after warming to 50℃ and 60℃ (r = 0.450 and P = 0.001; r = 0.351 and P = 0.015, respectively).

Conclusions

Rapid warming of irradiated leukoreduced RBCs to 50℃ may not further increase the extracellular release of hemoglobin or potassium. However, irradiated leukoreduced RBCs that have been in storage for long periods of time and contain higher levels of potassium should be infused with caution.

Gamma-irradiation of deglycerolized red cells does not significantly affect in vitro quality

BACKGROUND AND OBJECTIVES

Red cells frozen with glycerol may require gamma-irradiation after thawing and deglycerolization for transfusion to at-risk patients. Both freezing and irradiation are known to cause red cell damage. However, the effect of irradiation on the quality of deglycerolized red cells and the optimal shelf life of such a component is currently unknown.

MATERIALS AND METHODS

Red cells (<7 days) were pooled, split and glycerolized using an ACP-215 automated cell washer (n = 12 pairs) and frozen at -80°C. Red cells were thawed, deglycerolized and resuspended in SAG-M. One of each pair was gamma-irradiated, while the other served as a control. Products were stored at 2-6°C and sampled for in vitro testing immediately after irradiation, and at 24 and 48 h postirradiation.

RESULTS

Irradiation of deglycerolized red cells led to a >1·5-fold increase in extracellular potassium, compared to control units at 24 and 48 h postirradiation. Other parameters, including haemolysis, were not significantly affected by irradiation postdeglycerolization.

CONCLUSION

Deglycerolized, irradiated red cells had increased supernatant potassium, but remained of acceptable quality for 24 h postirradiation.

Evaluation of the effectiveness of packed red blood cell irradiation by a linear accelerator

Irradiation of blood components with ionizing radiation generated by a specific device is recommended to prevent transfusion-associated graft-versus-host disease. However, a linear accelerator can also be used in the absence of such a device, which is the case of the blood bank facility studied herein. In order to evaluate the quality of the irradiated packed red blood cells, this study aimed to determine whether the procedure currently employed in the facility is effective in inhibiting the proliferation of T lymphocytes without damaging blood components.

The proliferation of T lymphocytes, plasma potassium levels, and the degree of hemolysis were evaluated and compared to blood bags that received no irradiation. Packed red blood cell bags were irradiated at a dose of 25 Gy in a linear accelerator. For this purpose, a container was designed to hold the bags and to ensure even distribution of irradiation as evaluated by computed tomography and dose-volume histogram.

Irradiation was observed to inhibit the proliferation of lymphocytes. The percentage of hemolysis in irradiated bags was slightly higher than in non-irradiated bags (p-value >0.05), but it was always less than 0.4% of the red cell mass. Although potassium increased in both groups, it was more pronounced in irradiated red blood cells, especially after seven days of storage, with a linear increase over storage time.

The findings showed that, at an appropriate dosage and under validated conditions, the irradiation of packed red blood cells in a linear accelerator is effective, inhibiting lymphocyte proliferation but without compromising the viability of the red cells.

Increased mortality in adult patients with trauma transfused with blood components compared with whole blood

Hemorrhage is a preventable cause of death among patients with trauma, and management often includes transfusion, either whole blood or a combination of blood components (packed red blood cells, platelets, fresh frozen plasma). We used the 2009 National Trauma Data Bank data set to evaluate the relationship between transfusion type and mortality in adult patients with major trauma (n = 1745). Logistic regression analysis identified 3 independent predictors of mortality: Injury Severity Score, emergency medical system transfer time, and type of blood transfusion, whole blood or components. Transfusion of whole blood was associated with reduced mortality; thus, it may provide superior survival outcomes in this population.

A prospective study on red blood cell transfusion related hyperkalemia in critically ill patients

BACKGROUND

Transfusion-associated hyperkalemic cardiac arrest is a serious complication in patients receiving packed red blood cell (PRBC) transfusions. Mortality from hyperkalemia increases with large volumes of PRBC transfusion, increased rate of transfusion, and the use of stored PRBCs. Theoretically, hyperkalemia may be complicated by low cardiac output, acidosis, hyperglycemia, hypocalcemia, and hypothermia. In this study, we focus on transfusion-related hyperkalemia involving only medical intensive care unit (MICU) patients.

METHOD

This prospective observational study focuses on PRBC transfusions among MICU patients greater than 18 years of age. Factors considered during each transfusion included patient's diagnosis, indication for transfusion, medical co-morbidities, acid-base disorders, K(+) levels before and after each PRBC transfusion, age of stored blood, volume and rate of transfusion, and other adverse events. We used Pearson correlation and multivariate analysis for each factor listed above and performed a logistic regression analysis.

RESULTS

Between June 2011 and December 2011, 125 patients received a total of 160 units of PRBCs. Median age was 63 years (22 - 92 years). Seventy-one (57%) were females. Sixty-three patients (50%) had metabolic acidosis, 75 (60%) had acute renal failure (ARF), and 12 (10%) had end-stage renal disease (ESRD). Indications for transfusion included septic shock (n = 65, 52%), acute blood loss (n = 25, 20%), non-ST elevation myocardial infarction (NSTEMI) (n = 25, 20%) and preparation for procedures (n = 14, 11%). Baseline K(+) value was 3.9 ± 1.1 mEq/L compared to 4.3 ± 1.2 mEq/L post-transfusion respectively (P = 0.9). During this study period, 4% of patients developed hyperkalemia (K(+) 5.5 mEq/L or above). The mean change of serum potassium in patients receiving transfusion ≥ 12 days old blood was 4.1 ± 0.4 mEq/L compared to 4.8 ± 0.3 mEq/L (mean ± SD) in patients receiving blood 12 days or less old. Sixty-two patients (77.5%) that were transfused stored blood (for more than 12 days) had increased serum K(+); eight (17.7%) patients received blood that was stored for less than 12 days. In both univariate (P = 0.02) and multivariate (P = 0.04) analysis, findings showed that among all factors, transfusion of stored blood was the only factor that affected serum potassium levels (95% CI: 0.32 - 0.91). No difference was found between central and peripheral intravenous access (P = 0.12), acidosis (P = 0.12), ARF (P = 0.6), ESRD (P = 0.5), and multiple transfusions (P = 0.09). One subject developed a sustained cardiac arrest after developing severe hyperkalemia (K(+) = 9.0) following transfusion of seven units of PRBCs. Multivariate logistic regression showed linear correlation between duration of stored blood and serum K(+) (R(2) = 0.889).

CONCLUSION

This study assesses factors that affect K(+) in patients admitted to MICU. Results from the study show that rise in serum K(+) level is more pronounced in patients who receive stored blood (> 12 days). Future studies should focus on the use of altered storage solution, inclusion of potassium absorption filters during transfusion and cautious use of blood warmer in patients requiring massive blood transfusions.

Changes in potassium and sodium concentrations in stored blood

Potassium is the principal intracellular cation with sodium being the principal extracellular cation. Maintenance of the distribution of potassium and sodium between the intracellular and the extracellular compartments relies on several homeostatic mechanisms. This study analysed the effect of blood storage on the concentrations of potassium and sodium in stored blood and also determine any variations that may exist in their concentrations. 50 mls of blood was sampled each from 28 units of evenly mixed donated blood in citrate phosphate dextrose adenine (CPDA-1) bags immediately after donation into satellite bag and stored at 4oC. Potassium and sodium concentration determinations were done on each of the 28 samples on day 0 (before blood was initially stored in the fridge), day 5, day 10, day 15 and day 20 of storage using the Roche 9180 ISE Electrolyte Analyser (Hoffmann-La Roche Ltd, Switzerland). data analysis showed significant changes in the potassium and sodium concentrations with a continuous rise in potassium and a continuous fall in sodium. A daily change of 0.59 mmol/l and 0.50 mmol/l was observed in the potassium and sodium concentrations respectively. We showed steady but increased daily concentrations of potassium and decrease concentrations of sodium in blood stored over time at 4oC.