Cardiac arrests associated with hyperkalemia during red blood cell transfusion: a case series

Causes of Perioperative Cardiac Arrest: Mnemonic, Classification, Monitoring, and Actions

Perioperative cardiac arrest (POCA) is a catastrophic complication that requires immediate recognition and correction of the underlying cause to improve patient outcomes. While the hypoxia, hypovolemia, hydrogen ions (acidosis), hypo-/hyperkalemia, and hypothermia (Hs) and toxins, tamponade (cardiac), tension pneumothorax, thrombosis (pulmonary), and thrombosis (coronary) (Ts) mnemonic is a valuable tool for rapid differential diagnosis, it does not cover all possible causes leading to POCA. To address this limitation, we propose using the preload-contractility-afterload-rate and rhythm (PCARR) construct to categorize POCA, which is comprehensive, systemic, and physiologically logical. We provide evidence for each component in the PCARR construct and emphasize that it complements the Hs and Ts mnemonic rather than replacing it. Furthermore, we discuss the significance of utilizing monitored variables such as electrocardiography, pulse oxygen saturation, end-tidal carbon dioxide, and blood pressure to identify clues to the underlying cause of POCA. To aid in investigating POCA causes, we suggest the Anesthetic care, Surgery, Echocardiography, Relevant Check and History (A-SERCH) list of actions. We recommend combining the Hs and Ts mnemonic, the PCARR construct, monitoring, and the A-SERCH list of actions in a rational manner to investigate POCA causes. These proposals require real-world testing to assess their feasibility.

PROSPECTIVE EXAMINATION OF THE K/ICA RATIO AS A PREDICTOR FOR MORTALITY IN SEVERE HEMORRHAGE

ABSTRACT

Background: Patients receiving massive transfusion protocol (MTP) are at risk for posttransfusion hypocalcemia and hyperkalemia. Previous retrospective analysis has suggested the potassium/ionized calcium (K/iCa) ratio as a prognostic indicator of mortality. This prospective study sought to validate the value of the K/iCa ratio as a predictor for mortality in patients receiving MTP. Methods: This was a prospective analysis of adult trauma patients who underwent MTP activation from May 2019 to March 2021 at an urban level 1 trauma center. Serum potassium and iCa levels within 0 to 1 h of MTP initiation were used to obtain K/iCa. Receiver operator characteristic curve analysis assessed predictive capacity of K/iCa on mortality. Kaplan-Meier survival analysis and Cox regression examined the effect of K/iCa ratio on survival. Results: A total of 110 of 300 MTP activation patients met inclusion criteria. Overall mortality rate was 31.8%. No significant differences between the elevated K/iCa and lower K/iCa groups were found for prehospital or emergency department initial vitals, shock index, or injury severity. However, nonsurvivors had a significantly higher median K/iCa ratio compared with those who survived ( P < 0.01). Multivariable logistic regression revealed the total number of blood products to be significantly associated with elevated K/iCa (odds ratio, 1.02; 95% CI, 1.01-1.04; P = 0.01). The Kaplan Meier survival curve demonstrated a significantly increased rate of survival for those with an elevated K/iCa ratio ( P < 0.01). Multivariable Cox regression adjusted for confounders showed a significant association between K/iCa and mortality (Hazard Ratio, 4.12; 95% CI, 1.89-8.96; P < 0.001). Conclusion: This evidence further highlights the importance of the K/iCa ratio in predicting mortality among trauma patients receiving MTP. Furthermore, it demonstrates that posttransfusion K levels along with iCa levels should be carefully monitored in the MTP setting. Level of Evidence: Level II. Study Type: Prognostic/epidemiological.

High-Dose Insulin for Hyperkalemic Cardiac Arrest

ABSTRACT

Hyperkalemic cardiac arrest diagnosis can be elusive and management difficult as the cardiac rhythm restoration is often not achieved until the potassium level decreases to a relatively normal level for the patient who suffers the arrest. Current treatment modalities can take hours to achieve this goal. We describe two patients who survived a witnessed hyperkalemic cardiac arrest after being managed with conventional advanced cardiac life support and unconventionally high doses of intravenous insulin.

Biochemical disturbance in damage control resuscitation: mechanisms, management and prognostic utility

PURPOSE OF REVIEW

With advances in resuscitative techniques, trauma patients are surviving increasingly severe injuries and physiological insult. Timely recognition of futility remains important in terms of patient dignity and resource preservation yet is increasingly challenging in the face of these advances. The understanding of biochemical derangement from pathophysiological processes of trauma and iatrogenic effects of resuscitation has expanded recently.

RECENT FINDINGS

Acidosis and hypocalcaemia have been recognized as important contributors to mortality among trauma patients. Although less well recognized and studied, critical injury and high blood product volume resuscitation render patients vulnerable to life-threatening hyperkalaemia. The methods of correcting disruptions to acid-base and electrolyte homeostasis during damage control resuscitation have changed little recently and often rely on evidence from undifferentiated populations. Biochemical disturbances have value as ancillary predictors of futility in trauma resuscitation.

SUMMARY

These findings will contribute to a greater understanding among anaesthesiologists of the causative mechanisms and effects of biochemical derangement after severe injury and aid them in the delivery of well tolerated and effective damage control resuscitation. Gaps in the evidence base are highlighted to encourage future work.

Emerging technology for early detection and management of postpartum hemorrhage to prevent morbidity

Despite advances in hemorrhage detection and management, postpartum hemorrhage remains the single leading cause of maternal death worldwide. Within the United States, hemorrhage is the leading cause of maternal death on the day of delivery and within the first week after delivery. Blood transfusion after hemorrhage represents a large proportion of severe maternal morbidity during and after delivery. Blood loss during delivery has historically been assessed visually by inspecting soiled pads, linens, and laparotomy sponges. These methods underestimate the volume of blood loss by as much as 40%, becoming increasingly inaccurate as blood loss increases. Young, healthy obstetrical patients compensate for blood loss via peripheral vasoconstriction, maintaining heart rate and blood pressure in a normal range until over 1 L of blood has been lost. A significant decrease in blood pressure along with marked tachycardia (>120 bpm) may not be seen until 30% to 40% of blood volume has been lost, or 2.0 to 2.6 L in a healthy term pregnant patient, after which the patient may rapidly decompensate. In resource-poor settings especially, the narrow window between the emergence of significant vital sign abnormalities and clinical decompensation may prove catastrophic. Once hemorrhage is detected, decisions regarding blood product transfusion are routinely made on the basis of inaccurate estimates of blood loss, placing patients at risk of underresuscitation (increasing the risk of hemorrhagic shock and end-organ damage) or overresuscitation (increasing the risk of transfusion reaction, fluid overload, and alloimmunization). We will review novel technologies that have emerged to assist both in the early and accurate detection of postpartum hemorrhage and in decisions regarding blood product transfusion.

Impact of Transfusing Packed Red Blood Cells Through a Rapid Infuser on Potassium Levels

BACKGROUND

Hyperkalemia is associated with the rapid transfusion of packed red blood cells in trauma patients. Rapid infusers can infuse blood up to 500 ml/min.

OBJECTIVE

This study aimed to determine whether infusing packed red blood cells through a rapid infuser impacts the potassium levels of the infused blood.

METHODS

Two baseline samples were obtained to measure potassium and hemolysis scores in 12 units of expired blood prior to infusion. The blood was then infused via the Belmont Rapid Infuser into collection bags at varying infusion rates (50, 100, 250, and 500 ml/min) utilizing different gauge catheter sizes (18-gauge, 16-gauge, and Cordis catheter). Two postinfusion blood samples were collected and tested for potassium and hemolysis scores and compared with preinfusion values. This process was then repeated with fresh blood.

RESULTS

The potassium levels of the samples taken from each unit prior to infusion (average difference 0.245) and after infusion (average difference 0.08) correlated well. There was no difference in potassium levels pre- and postinfusion at any infusion rate after accounting for catheter size and age of blood. The median potassium level of the fresh blood was 5.025 prior to infusion and 4.875 after infusion. The median potassium level of the expired blood was 16.05 prior to infusion and 16.4 postinfusion. There was no significant difference in the hemolysis scores between the preinfusion and postinfusion samples.

CONCLUSIONS

Hyperkalemia in trauma patients undergoing massive transfusions is not a result of mechanical hemolysis from the high rates of blood infusion.

Sustained hyperkalemia in an asymptomatic primary care patient. When to suspect familial pseudohyperkalemia

Objectives

Study and management of a case with elevated potassium levels without apparent clinical causes in successive follow-up visits.

Case presentation

We present the case of a primary care female patient who persistently exhibited elevated levels of potassium (5.3-5.9 mmol/L) in successive control laboratory tests, without an apparent clinical cause. The patient was ultimately referred to the Unit of Nephrology, where a potassium-low diet was indicated. Diet did not have any effect on potassium levels. After a thorough study, the cause of hyperkalemia could not be determined.

Conclusions

The inconsistency between elevated potassium levels and the reason of consultation, and exclusion of other pre-analytical or pathological causes raised suspicion of familial pseudohyperkalemia. The sample was incubated at different times and temperatures to demonstrate their influence on levels of potassium in blood. Familial pseudohyperkalemia was established as the most probable diagnosis. Finally, the patient was discharged from the Unit of Nephrology and instructed to follow a normal diet.

Adverse transfusion reactions and what we can do

INTRODUCTION

Transfusions of blood and blood components have inherent risks and the ensuing adverse reactions. It is very important to understand the adverse reactions of blood transfusion comprehensively for ensuring the safety of any future transfusions.

AREAS COVERED

According to the time of onset, adverse reactions of blood transfusion are divided into immediate and delayed transfusion reactions. In acute transfusion reactions, timely identification and immediate cessation of transfusion is critical. Vigilance is required to distinguish delayed responses or reactions that present non-specific signs and symptoms. In this review, we present the progress of mechanism, clinical characteristics and management of commonly encountered transfusion reactions.

EXPERT OPINION

The incidence of many transfusion-related adverse events is decreasing, but threats to transfusion safety are always emerging. It is particularly important for clinicians and blood transfusion staff to recognize the causes, symptoms and treatment methods of adverse blood transfusion reactions to improve the safety. In the future, at-risk patients will be better identified and can benefit from more closely matched blood components.

Potassium Level Variation Following Packed Cell Transfusion in Critically Ill Adult Patients-How Alert Should We Be?

One of the most clinically important effects following the administration of packed cell transfusion (PCT) is hyperkalemia, which can cause severe life-threatening cardiac arrhythmias. This retrospective population-based cohort study included adults hospitalized between January 2007 and December 2019 in a general intensive care unit for 24 h or more, with normal levels of serum potassium on admission. We assessed changes in serum potassium levels after administration of one unit of packed cells and sought to identify clinical parameters that may affect these changes. We applied adjusted linear mixed models to assess changes in serum potassium. The mean increase in serum potassium was 0.09 mEq/L (C.U 0.04−0.14, p-value < 0.001) among the 366 patients who were treated with a single PCT compared to those not treated with PCT. Increased serum potassium levels were also found in patients who required mechanical ventilation, and to a lesser degree in those treated with vasopressors. Hypertension, the occurrence of a cerebrovascular accident, and increased creatinine levels were all associated with reduced serum potassium levels. Due to the small rise in serum potassium levels following PCT, we do not suggest any particular follow-up measures for critically ill patients who receive PCT.

Blood Transfusion Reactions-A Comprehensive Review of the Literature including a Swiss Perspective

Blood transfusions have been the cornerstone of life support since the introduction of the ABO classification in the 20th century. The physiologic goal is to restore adequate tissue oxygenation when the demand exceeds the offer. Although it can be a life-saving therapy, blood transfusions can lead to serious adverse effects, and it is essential that physicians remain up to date with the current literature and are aware of the pathophysiology, initial management and risks of each type of transfusion reaction. We aim to provide a structured overview of the pathophysiology, clinical presentation, diagnostic approach and management of acute transfusion reactions based on the literature available in 2022. The numbers of blood transfusions, transfusion reactions and the reporting rate of transfusion reactions differ between countries in Europe. The most frequent transfusion reactions in 2020 were alloimmunizations, febrile non-hemolytic transfusion reactions and allergic transfusion reactions. Transfusion-related acute lung injury, transfusion-associated circulatory overload and septic transfusion reactions were less frequent. Furthermore, the COVID-19 pandemic has challenged the healthcare system with decreasing blood donations and blood supplies, as well as rising concerns within the medical community but also in patients about blood safety and transfusion reactions in COVID-19 patients. The best way to prevent transfusion reactions is to avoid unnecessary blood transfusions and maintain a transfusion-restrictive strategy. Any symptom occurring within 24 h of a blood transfusion should be considered a transfusion reaction and referred to the hemovigilance reporting system. The initial management of blood transfusion reactions requires early identification, immediate interruption of the transfusion, early consultation of the hematologic and ICU departments and fluid resuscitation.

Case Report: Familial Pseudohyperkalemia Due to Red Blood Cell Membrane Leak in a Chinese Patient

Hyperkalemia is a critical condition requiring careful evaluation and timely intervention. Many conditions could manifest as pseudohyperkalemia and it's important to differentiate them as inappropriate potassium-lowering therapy might lead to detrimental outcomes. A 56-year-old female was admitted for hyperkalemia (5.62–8.55 mmol/L). She had no symptoms or signs of hyperkalemia. A comprehensive work-up of hyperkalemia retrieved no valuable findings. Her blood samples underwent incubation tests at different temperatures and revealed temperature-dependent potassium leaks from red blood cells. Based on all test results, a diagnosis of hyperkalemia caused by red blood cell membrane defects was suspected. Whole-genome sequencing revealed a heterozygous c.1123C>T (p. R375W) mutation in the ABCB6 gene and confirmed the diagnosis of familial pseudohyperkalemia (FP). FP is an inherited benign condition in which red blood cells have increased cold-induced permeability to potassium. The patient was discharged with no additional treatment and she was suggested avoiding blood donation.

An Overview of Therapy Guidelines for Cardiac Arrest and the Potential Benefits of Hemoglobin-Based Oxygen Carriers

Currently, there is an unmet therapeutic need for the medical management of cardiac arrest, as is evident from the high mortality rate associated with this condition. These dire outcomes can be attributed to the severe nature and poor prognosis of this disorder. However, the current treatment modalities, while helping to augment survival, are limited and do not offer adequate improvements to outcomes. Treatment modalities are particularly lacking when considering the underlying pathophysiology of the metabolic phase of cardiac arrest. In this study, we explore the three phases of cardiac arrest and assess the factors related to positive clinical outcomes and survival for these events. Furthermore, we evaluate the present guidelines for resuscitation and recovery, the issues related to ischemia and tissue reperfusion, and the benefit of oxygen-delivery therapeutic methods including blood transfusion therapy and synthetic hemoglobins (HBOCs). The current therapy protocols are limited specifically by the lack of an efficient method of oxygen delivery to address the metabolic phase of cardiac arrest. In this article, we investigate the next generation of HBOCs and review their properties that make them attractive for their potential application in the treatment of cardiac arrest. These products may be a viable solution to address complications associated with ischemia, reperfusion injury, and organ damage.

Measuring potassium level in packed red blood cells before using: Word of caution for congenital cardiac surgery

BACKGROUND AND AIM OF THE STUDY

Transfusion-associated hyperpotassemia is a serious complication of packed red blood cell (PRBC) transfusion after congenital cardiac surgery. Our study aimed to identify risk factors and potential preventive measures of transfusion-associated hyperpotassemia in neonates and infants after congenital cardiac surgery.

METHODS

Pediatric patients who underwent congenital cardiac surgery and need transfusion were enrolled in this prospective study. The potassium concentration of PRBC was checked from the sample taken from the segment. The volume of transfusion, age of PRBC, potassium concentration of unit were recorded. The estimated increment of potassium level in patients after PRBC transfusion was calculated.

RESULTS

Seventy-four individual patients, 95 distinct transfusions, 112 blood products were evaluated. The mean age of the blood unit was 3.8 ± 1.4 days. The mean potassium concentration in the PRBCs was 9.9 ± 2.4 mmol/L. A weak correlation was observed between the potassium value of the PRBC and the age of PRBC (p = 0.049, r = 0.2, y = 0.24 × x + -0.68). There was a weak correlation between the potassium value of PRBCs and the age of the unit (p < 0.001, r = 0.37, y = 2.8 × x + -3.6).

CONCLUSIONS

Before transfusion, even PRBC is fresh, measuring the potassium level of PRBC and the potassium that will be given to the pediatric patient with transfusion can prevent transfusion-related hyperpotassemia and related complications. Otherwise, high potassium levels, which may be overlooked despite being fresh, may cause serious complications, even cardiac arrest, especially in neonates and infants.

Successful Management of a Patient with Intraoperative Bleeding of More than 80,000 mL and Usefulness of QTc Monitoring for Calcium Correction

Intraoperative massive bleeding is associated with high rates of mortality and anesthetic management of massive bleeding is challenging because it is necessary to achieve volume resuscitation and electrolyte correction simultaneously during massive transfusion. We report a case of life-threatening bleeding of more than 80,000 mL during liver transplantation in which real-time QTc monitoring was useful for an extremely large amount of calcium administration for treatment of hypocalcemia. A 47-year-old female with a giant liver due to polycystic liver disease was scheduled to undergo liver transplantation. During surgery, life-threatening massive bleeding occurred. The maximum rate of blood loss was approximately 15,000 mL/hr and the total amount of estimated blood loss was 81,600 mL. It was extremely difficult to maintain blood pressure and a risk of cardiac arrest continued due to hypotension. In addition, even though administration of insulin and calcium was performed, electrolyte disturbances of hyperkalemia and hypocalcemia with prolongation of QTc interval occurred. At that time, we visually noticed that the QT interval was shortened in response to bolus calcium administration, and we used the change of real-time QTc interval as a supportive indicator for calcium correction. This monitoring allowed for us to administer calcium at an unusually high rate, by which progression of hypocalcemia was prevented. Levels of hemoglobin and coagulation factors were preserved both by restriction of crystalloid infusion and by a massive transfusion protocol. The patient was extubated without pulmonary edema or cardiac overload and was finally discharged without any sequelae. Intensive and cooperative management for massive transfusion and electrolyte correction using QTc monitoring was considered to be a key for successful management.

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.

Perceptions About Blood Transfusion Therapy Among the General Public and Healthcare Professionals in the Qassim Region of Saudi Arabia

Purpose

Blood transfusion is a conventional therapeutic procedure; however, the perceptions of general public and healthcare professionals (HCPs), especially physicians and nurses, remain unclear, although the insights of HSPs may affect the treatment decision. This study aimed to assess the awareness of HCPs and the public about blood transfusion risks and consent in Qassim region of Saudi Arabia, to uncover the factors that may influence such perceptions.

Patients and Methods

This study used two different closed questionnaires that were distributed electronically between February and March 2018 among the population and HCPs in Qassim region.

Results

A total of 400 general public participants and 135 HCPs completed the survey. Among the surveyed participants, 70% believed that blood transfusion therapy was safe. The perceived risk of human immunodeficiency virus (HIV)/acquired immunodeficiency syndrome (AIDS) was the highest among all complications (74%). Furthermore, 88.2% of respondents were willing to accept a blood transfusion as a therapeutic measure, primarily from a first-degree relative, although the remaining 11.8% rejected the idea of a transfusion due to fear of medical error. From the HCP survey, 80% were previously involved in a blood transfusion therapy consent process. HCPs typically reported explaining the benefits, risks, and alternatives described in the consent form (74.1%, 67.4%, and 53.3%, respectively).

Conclusion

Our results indicated that despite the current high level of acceptance and knowledge regarding blood transfusions, additional educational efforts remain necessary to increase public awareness of blood transfusion therapy.

Bedside Allogeneic Erythrocyte Washing with a Cell Saver to Remove Cytokines, Chemokines, and Cell-derived Microvesicles

BACKGROUND

Removal of cytokines, chemokines, and microvesicles from the supernatant of allogeneic erythrocytes may help mitigate adverse transfusion reactions. Blood bank-based washing procedures present logistical difficulties; therefore, we tested the hypothesis that on-demand bedside washing of allogeneic erythrocyte units is capable of removing soluble factors and is feasible in a clinical setting.

METHODS

There were in vitro and prospective, observation cohort components to this a priori planned substudy evaluating bedside allogeneic erythrocyte washing, with a cell saver, during cardiac surgery. Laboratory data were collected from the first 75 washed units given to a subset of patients nested in the intervention arm of a parent clinical trial. Paired pre- and postwash samples from the blood unit bags were centrifuged. The supernatant was aspirated and frozen at -70°C, then batch-tested for cell-derived microvesicles, soluble CD40 ligand, chemokine ligand 5, and neutral lipids (all previously associated with transfusion reactions) and cell-free hemoglobin (possibly increased by washing). From the entire cohort randomized to the intervention arm of the trial, bedside washing was defined as feasible if at least 75% of prescribed units were washed per protocol.

RESULTS

Paired data were available for 74 units. Washing reduced soluble CD40 ligand (median [interquartile range]; from 143 [1 to 338] ng/ml to zero), chemokine ligand 5 (from 1,314 [715 to 2,551] to 305 [179 to 488] ng/ml), and microvesicle numbers (from 6.90 [4.10 to 20.0] to 0.83 [0.33 to 2.80] × 106), while cell-free hemoglobin concentration increased from 72.6 (53.6 to 171.6) mg/dl to 210.5 (126.6 to 479.6) mg/dl (P < 0.0001 for each). There was no effect on neutral lipids. Bedside washing was determined as feasible for 80 of 81 patients (99%); overall, 293 of 314 (93%) units were washed per protocol.

CONCLUSIONS

Bedside erythrocyte washing was clinically feasible and greatly reduced concentrations of soluble factors thought to be associated with transfusion-related adverse reactions, increasing concentrations of cell-free hemoglobin while maintaining acceptable (less than 0.8%) hemolysis.

EDITOR’S PERSPECTIVE

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.

Assessment of a downsized potassium adsorption filter designed to transfuse neonates

BACKGROUND

During storage, the potassium level of red blood cell (RBC) components increases, especially after irradiation. Neonates are prone to hyperkalemia, for example, non-oliguric hyperkalemia, so using potassium adsorption filters during transfusion may be helpful. To overcome dilution of RBC components caused by saline priming of existing potassium adsorption filters, a downsized potassium adsorption filter for neonates (PAF-n, Kawasumi Laboratories Inc., Tokyo, Japan) was developed.

STUDY DESIGN AND METHODS

To assess the performance of PAF-n, its adsorption efficiency and RBC recovery rate were evaluated by testing pre-filtration and serial post-filtration (0-30 mL, 30-60 mL, 60-90 mL, and 90-120 mL) samples from 8 RBC components.

RESULTS

The average potassium adsorption rate of the PAF-n was 90.5% ± 0.78%, and never less than 89.0% in any of 8 RBC components. RBC recovery rates were 99.3% ± 1.12%.

CONCLUSION

The PAF-n showed an effective potassium ability with negligible RBC dilution.

Potential Consequences of the Red Blood Cell Storage Lesion on Cardiac Electrophysiology

Background The red blood cell (RBC) storage lesion is a series of morphological, functional, and metabolic changes that RBCs undergo following collection, processing, and refrigerated storage for clinical use. Since the biochemical attributes of the RBC unit shifts with time, transfusion of older blood products may contribute to cardiac complications, including hyperkalemia and cardiac arrest. We measured the direct effect of storage age on cardiac electrophysiology and compared it with hyperkalemia, a prominent biomarker of storage lesion severity. Methods and Results Donor RBCs were processed using standard blood-banking techniques. The supernatant was collected from RBC units, 7 to 50 days after donor collection, for evaluation using Langendorff-heart preparations (rat) or human induced pluripotent stem cell-derived cardiomyocytes. Cardiac parameters remained stable following exposure to "fresh" supernatant from red blood cell units (day 7: 5.8±0.2 mM K+), but older blood products (day 40: 9.3±0.3 mM K+) caused bradycardia (baseline: 279±5 versus day 40: 216±18 beats per minute), delayed sinus node recovery (baseline: 243±8 versus day 40: 354±23 ms), and increased the effective refractory period of the atrioventricular node (baseline: 77±2 versus day 40: 93±7 ms) and ventricle (baseline: 50±3 versus day 40: 98±10 ms) in perfused hearts. Beating rate was also slowed in human induced pluripotent stem cell-derived cardiomyocytes after exposure to older supernatant from red blood cell units (-75±9%, day 40 versus control). Similar effects on automaticity and electrical conduction were observed with hyperkalemia (10-12 mM K+). Conclusions This is the first study to demonstrate that "older" blood products directly impact cardiac electrophysiology, using experimental models. These effects are likely caused by biochemical alterations in the supernatant from red blood cell units that occur over time, including, but not limited to hyperkalemia. Patients receiving large volume and/or rapid transfusions may be sensitive to these effects.

Red Blood Cells Derived from Whole Blood Treated with Riboflavin and UV Light Maintain Adequate Cell Quality through 21 Days of Storage

BACKGROUND

The Mirasol system for whole blood (WB) is a non-toxic, non-mutagenic pathogen reduction technology (PRT) that treats WB units with riboflavin (vitamin B2) and ultraviolet (UV) light to alter nucleic acids, thereby reducing pathogen infectivity and inactivating white blood cells. This study evaluates the quality of red blood cells (RBCs) derived from WB treated with the Mirasol system.

STUDY DESIGN AND METHODS

Paired units of WB were collected from 61 healthy donors. One unit per donor was treated with riboflavin and UV light and the other was used as an untreated control. RBCs were processed from the WB units and stored in AS-3 at 1-6°C for 21 days and sampled for in vitro analyses of RBC quality parameters.

RESULTS

Several statistically significant differences were observed between test and control units, but values were overall within normal clinical ranges. After leukoreduction, the residual leukocyte count and RBC recovery met FDA requirements. The RBC units derived from treated WB maintained haemolysis below 1% through 21 days of storage.

CONCLUSION

RBCs derived from WB treated with the Mirasol system meet accepted FDA guidelines for RBC quality through 21 days of storage at 1-6°C.

Advantages of early intervention with arterial embolization for intra-abdominal solid organ injuries in children

PURPOSE

Active bleeding due to abdominal trauma is an important cause of mortality in childhood. The aim of this study is to demonstrate the advantages of early percutaneous transcatheter arterial embolization (PTAE) procedures in children with intra-abdominal hemorrhage due to blunt trauma.

METHODS

Children with blunt abdominal trauma were retrospectively included. Two groups were identified for inclusion: patients with early embolization (EE group, n=10) and patients with late embolization (LE group, n=11). Both groups were investigated retrospectively and statistically analyzed with regard to lengths of stay in the intensive care unit and in the hospital, first enteral feeding after trauma, blood transfusion requirements, and cost.

RESULTS

The duration of stay in the intensive care unit was greater in the LE group than in the EE group (4 days vs. 2 days, respectively). The duration of hospital stay was greater in the LE group than in the EE group (14 days vs. 6 days, respectively). Blood transfusion requirements (15 cc/kg of RBC packs) were greater in the LE group than in the EE group (3 vs. 1, respectively). The total hospital cost was higher in the LE group than in the EE group (4502 USD vs. 1371.5 USD, respectively). The time before starting enteral feeding after first admission was higher in the LE group than in the EE group (4 days vs. 1 day, respectively).

CONCLUSION

Early embolization with PTAE results in shorter intensive care and hospitalization stays, earlier enteral feeding, and lower hospital costs for pediatric patients with intra-abdominal hemorrhage due to blunt trauma.

Effects of irradiation and leukoreduction on down-regulation of CXCL-8 and storage lesion in stored canine whole blood

White blood cells (WBCs) and storage period are the main factors of transfusion reactions. In the present study, cytokine/chemokine concentrations after leukoreduction (LR) and irradiation (IR) in stored canine whole blood were measured. Red blood cell storage lesion caused by IR and LR were also compared. Blood samples from 10 healthy Beagles were divided into four groups (no treatment, LR-, IR-, and LR + IR-treated). Leukocytes were removed by filtration in the LR group and gamma radiation (25 Gy) was applied in the IR group. Immunologic factors (WBCs, interleukin-6 [IL-6], C-X-C motif chemokine ligand 8 [CXCL-8], and tumor necrosis factor-alpha) and storage lesion factors (blood pH, potassium, and hemolysis) were evaluated on storage days 0, 7, 14, 21, and 28. Compared to the treated groups, IL-6 and CXCL-8 concentrations during storage were significantly higher in the control (no treatment) group. LR did not show changes in cytokine/chemokine concentrations, and storage lesion presence was relatively mild. IR significantly increased CXCL-8 after 14 days of storage, but IR of leukoreduced blood did not increase CXCL-8 during 28 days of storage. Storage lesions such as hemolysis, increased potassium, and low pH were observed 7 days after IR and storage of blood, regardless of LR. IR of leukoreduced blood is beneficial to avoid immune reactions; however, storage lesions should be considered upon storage.

Hemolysis risk after packed red blood cells transfusion with infusion pumps

OBJECTIVE

To evaluate the hemolysis biomarkers of packed red blood cells transfused by two different linear peristaltic infusion pumps at two infusion rates.

METHOD

An experimental and randomized study was designed simulating the clinical practice of transfusion. Two linear peristaltic infusion pumps from different manufactures were studied in triplicate at 100 mL/h and 300mL/h infusion rates. The chosen hemolysis biomarkers were total hemoglobin, free hemoglobin, hematocrit, potassium and degree of hemolysis. They were analyzed before and after each infusion.

RESULTS

Potassium showed statistically significant variations in all scenarios of the experiment (P<0.010). In a separated analysis, potassium increased mainly at 300mL/h rate (P=0.021) and free hemoglobin had significant variation when comparing infusion pumps from different manufacturers (P=0.026). Although hematocrit, total hemoglobin and degree of hemolysis had increased after infusion, no statistically significance variations were identified.

CONCLUSIONS

Hemolysis risk induced by a linear peristaltic infusion pump was identified by an increase in free hemoglobin and potassium markers. As the potassium biomarker is often increased in aged packed red blood cells, we do not recommend using them in this scenario. Additional studies should be performed about other markers and using larger samples in order to reinforce the transfusion practice in nursing.

Biochemical changes in stored donor units: implications on the efficacy of blood transfusion

Background

Blood transfusion with allogeneic blood products is a common medical intervention to treat anemia or prepare patients for surgical procedures. Generally, the blood units are secured and stored prior to expected transfusion. During storage, a number of biochemical changes occur (generally known as storage lesion), which can affect the efficacy of blood transfusion. The aim of the study was to evaluate the biochemical changes that occur in blood units during storage and to project the impact of these changes on transfusion.

Methods

The study protocol was approved by the Faculty of Medicine Research Ethics committee of Mbarara University of Science and Technology. A total of 200 blood recipients were categorized into two study arms: group I received fresh blood (n=100) and group II received old blood (n=100), who were formally consented and recruited consecutively. A total of 2 mL of venous blood was collected from each participant in EDTA tubes before transfusion (for pre-transfusion hemoglobin [Hb] estimation) and after transfusion (for post-transfusion Hb estimation). Each crossmatched unit was sampled to collect plasma for pH, lactate and potassium assays. Data were analyzed with STATA version 12.0.

Results

A total of 200 blood transfusion recipients aged 1–60 years were enrolled in the study. Up to 60% of the participants were females. The pH of the stored blood dropped from 7.4 to 7.2 in the first 3 days to ~7.0 by day 11 and to <7.0 by day 35 (p=0.03). The average rise in lactate level was 25 g/dL in blood stored for 0 to 11 days and 32.4 g/dL in blood stored for 21–35 days. The highest increase was encountered in blood stored beyond 28 days: 40–57 g/dL by 35 days (p=0.001). Potassium levels equally increased from ~4.6 mmol/L in the first 5 days of storage to ~14.3 mmol/L by 11 days. From the third week of blood storage and beyond, there was exponential increase in potassium levels, with the highest record in blood units stored from 30 to 35 days (p=0.068).

Conclusion

Whole blood stored for >14 days has reduced efficacy with increased markers of red cell storage lesion such as increased potassium level, lactate and fall in pH. These lesions increase the length of hospital stay.

Levels of Hemolysis Markers in Erythrocyte Concentrates Administered Using a Syringe Infusion Pump

Syringe infusion pumps (SIPs) led to major advances in infusion therapy and were gradually applied to the transfusion of packed red blood cells (RBCs), raising questions about possible cell damage. The objectives of this study were to determine levels of hematocrit (%), total hemoglobin (g/dL), free hemoglobin (g/dL), lactate dehydrogenase (units/L), potassium (mmol/L), the degree of hemolysis (%) of RBCs infused by an SIP, and to investigate the influence of the infusion rate. The experimental study comprised 14 RBCs, 3 SIPs, and infusion rates of 5, 10, and 20 mL/h. The results showed total hemoglobin reduction (P = .003), and increased free hemoglobin and hemolysis (P <.001) were identified. The conclusion reached was that RBCs presented changes in free hemoglobin and degree of hemolysis.

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.

From Donor to Recipient: Considerations for Blood Transfusion Outcomes Research

Donated blood can be broken down into blood components for use in patient care. This article focuses primarily on packed red blood cells (PRBCs), as they experience breakdown during storage that may adversely impact patient outcomes. Patients require PRBC transfusions for a number of clinical reasons. Although transfusions of PRBCs provide some clinical benefit, they are also associated with increased morbidity and mortality across multiple patient populations, albeit the mechanisms underlying this relationship remain unclear. With an aging, more acutely ill population requiring aggressive treatment and a lack of transfusion alternatives, research focused on PRBCs has gained momentum. Proper interpretation of research findings on the part of clinicians depends on accurate data collection that includes aspects of both the transfused blood components and the recipients. The purpose of this article is to examine stored PRBC factors, blood-donor characteristics, transfusion-specific factors, and patient-specific characteristics as they relate to patient outcomes research. Challenges associated with performing and interpreting outcomes of transfusion-related research are presented. Implications of current evidence for patient care, such as awareness of benefits as well as risks associated with blood component transfusion, are also provided.

Transfusion Therapy in Children With Sickle Cell Disease

Hydroxyurea, blood transfusions, and hematopoietic stem cell transplantation represent the 3 disease-modifying therapies in children with sickle cell disease (SCD). Blood transfusions play an increasingly important role in both prevention and management of SCD complications in this age group. This review will focus on the indications of blood transfusion in children with SCD and modalities of its administration. It will also highlight the complications of this life-saving therapy and ways of optimizing transfusion to minimize its associated risks.

Hyperkalemia caused by rapid red cell transfusion and the potassium absorption filter

We report a case of transient hyperkalemia during hysterectomy after cesarean section, due to preoperatively undiagnosed placenta accreta that caused unforeseen massive hemorrhage and required rapid red cell transfusion. Hyperkalemia-induced by rapid red cell transfusion is a well-known severe complication of transfusion; however, in patients with sudden massive hemorrhage, rapid red cell transfusion is necessary to save their life. In such cases, it is extremely important to monitor serum potassium levels. For an emergency situation, a system should be developed to ensure sufficient preparation for immediate transfusion and laboratory tests. Furthermore, sufficient stock of preparations to treat hyperkalemia, such as calcium preparations, diuretics, glucose, and insulin is required. Moreover, a transfusion filter that absorbs potassium has been developed and is now available for clinical use in Japan. The filter is easy to use and beneficial, and should be prepared when it is available.

Study of Hemolysis During Storage of Blood in the Blood Bank of a Tertiary Health Care Centre

The aim of RBC storage system in a blood bank is to counteract damage to the metabolic machinery and the membrane, to improve post-transfusion viability. In recent years, the need for strict control over the quality of blood has been emphasised. Such quality indicator includes extend of hemolysis and morphological changes of RBC during storage. This study was design to see extend of hemolysis and level of plasma lactate dehydrogenase (LDH) and plasma potassium, during processing and storage at different intervals under blood bank condition. Forty-six donors were selected and blood units were collected and stored under blood bank conditions. Mean plasma haemoglobin of stored blood was estimated by tetra methyl benzidine method (TMB) and percentage hemolysis was calculated on day 0, 1, 7, 21, 28, 35 and 42 days. Similarly plasma LDH and plasma potassium level was also assessed during storage. It was noted that free haemoglobin level and percentage hemolysis progressively increased with storage along with the level of LDH and potassium. However, extend of hemolysis did not exceed the permissible limit of 0.8% up to 42 days of storage. 15 blood bags which showed visual hemolysis on day 28 did not exceeded the threshold of 0.8% hemolysis, when interpreted by TMB method. It was concluded that TMB method is better than visual method for determination of hemolysis. The reduced hemolysis at this centre may be accounted for the use of additive solution SAGM (Saline, Adenine, Glucose, Mannitol) and DEHP (di-2-ethyl hexyl phthalate) as plasticizer in blood bags for storage.

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.

Predictive Risk Factors in the Development of Intraoperative Hyperkalemia in Adult Living Donor Liver Transplantation

BACKGROUND

Hyperkalemia, defined as a serum potassium level higher than 5 mEq/L, is common in the liver transplantation setting. Severe hyperkalemia may induce fatal cardiac arrhythmias; therefore, it should be monitored and treated accordingly. The aim of the current retrospective study is to evaluate and indentify the predictive risk factors of hyperkalemia during living-donor liver transplantation (LDLT).

METHODS AND PATIENTS

Four hundred eighty-seven adult LDLT patients were included in the study. Intraoperative serum potassium levels were monitored at least five times during LDLT; patients with a potassium level higher than 5 mEq/L were included in group 1, and the others with normokalemia in group 2. Patients' categorical characteristics and intraoperative numeric variables with a P value <.1 were selected into a multiple binary logistic regression model. In multivariate analysis, a P value of <.05 is regarded as a risk factor in the development of hyperkalemia.

RESULTS

Fifty-one of 487 (10.4%) patients had hyperkalemia with a serum potassium level higher than 5.0 mEq/L during LDLT. Predictive factors with P < .1 in univariate analysis (Table 1), such as anesthesia time, preoperative albumin level, Model for End-stage Liver Disease score, preoperative bilirubin level, amount of blood loss, red blood cell (RBC) and fresh frozen plasma transfused, 5% albumin administered, hemoglobin at the end of surgery, and the amount of furosemide used, were further analyzed by multivariate binary regression. Results show that the anesthesia time, preoperative serum albumin level, and RBC count are determinant risk factors in the development of the hyperkalemia in our LDLT serials.

CONCLUSION

Prolonged anesthesia time, preoperative serum albumin level, and intraoperative RBC transfusion are three determinant factors in the development of intraoperative hyperkalemia, and close monitoring of serum potassium levels in patients with abovementioned risk factors are recommended.

Functional characterization of novel ABCB6 mutations and their clinical implications in familial pseudohyperkalemia

Isolated familial pseudohyperkalemia is a dominant red cell trait characterized by cold-induced 'passive leak' of red cell potassium ions into plasma. The causative gene of this condition is ABCB6, which encodes an erythrocyte membrane ABC transporter protein bearing the Langereis blood group antigen system. In this study analyzing three new families, we report the first functional characterization of ABCB6 mutants, including the homozygous mutation V454A, heterozygous mutation R276W, and compound heterozygous mutations R276W and R723Q (in trans). All these mutations are annotated in public databases, suggesting that familial pseudohyperkalemia could be common in the general population. Indeed, we identified variant R276W in one of 327 random blood donors (0.3%). Four weeks' storage of heterozygous R276W blood cells resulted in massive loss of potassium compared to that from healthy control red blood cells. Moreover, measurement of cation flux demonstrated greater loss of potassium or rubidium ions from HEK-293 cells expressing ABCB6 mutants than from cells expressing wild-type ABCB6. The R276W/R723Q mutations elicited greater cellular potassium ion efflux than did the other mutants tested. In conclusion, ABCB6 missense mutations in red blood cells from subjects with familial pseudohyperkalemia show elevated potassium ion efflux. The prevalence of such individuals in the blood donor population is moderate. The fact that storage of blood from these subjects leads to significantly increased levels of potassium in the plasma could have serious clinical implications for neonates and infants receiving large-volume transfusions of whole blood. Genetic tests for familial pseudohyperkalemia could be added to blood donor pre-screening. Further study of ABCB6 function and trafficking could be informative for the study of other pathologies of red blood cell hydration.

Protocols for massive blood transfusion: when and why, and potential complications

PURPOSE

An update paper on massive bleeding after major trauma. A review of protocols to address massive bleeding, and its possible complications, including coagulation abnormalities, complications related to blood storage, immunosuppression and infection, lung injury associated with transfusion, and hypothermia is carried out.

METHODS

Literature review and discussion with authors' experience.

RESULTS

Massive bleeding is an acute life-threatening complication of major trauma, and consequently its prompt diagnosis and treatment is of overwhelming importance. Treatment requires rapid surgical management together with the massive infusion of colloid and blood.

CONCLUSIONS

Since massive transfusion provokes further problems in patients who are already severely traumatized and anaemic, once this course of action has been decided upon, a profound knowledge of its potential complications, careful monitoring and proper follow-up are all essential. To diagnose this bleeding, most authors favour, as the main first choice tool, a full-body CT scan (head to pelvis), in non-critical severe trauma cases. In addition, focused abdominal sonography for trauma (FAST, an acronym that highlights the necessity of rapid performance) is a very important diagnostic test for abdominal and thoracic bleeding. Furthermore, urgent surgical intervention should be undertaken for patients with significant free intraabdominal fluid and haemodynamic instability. Although the clinical situation and the blood haemoglobin concentration are the key factors considered in this rapid decision-making context, laboratory markers should not be based on a single haematocrit value, as its sensitivity to significant bleeding may be very low. Serum lactate and base deficit are very sensitive markers for detecting and monitoring the extent of bleeding and shock, in conjunction with repeated combined measurements of prothrombin time, activated partial thromboplastin time, fibrinogen and platelets.

Blood component preferences of transfusion services supporting infant transfusions: a University HealthSystem Consortium benchmarking study

BACKGROUND

The extent of acceptability of red blood cells (RBCs) containing additive solutions (ASs) for low-volume neonatal transfusions among hospitals is unknown. Also unknown is whether hospitals have policies that address the risk of hyperkalemia associated with prolonged storage either with or without irradiation for neonatal transfusions.

STUDY DESIGN AND METHODS

A benchmarking survey of University HealthSystem Consortium members included questions regarding the acceptability of RBC units containing ASs for low-volume neonatal transfusions, policies addressing the length of RBC storage in AS, and policies regarding storage periods after irradiation.

RESULTS

Twenty-eight of 47 respondents (60%) accept the use of at least one AS (AS-1, AS-3, or AS-5). Twenty-one (45%) accept the use of all three ASs for neonatal transfusions. Thirty-seven of 45 respondents (82%) do not have a policy requiring washing of RBCs used for low-volume transfusions beyond a specified number of days of storage or days after irradiation.

CONCLUSIONS

Although the majority of institutions will use ASs, a significant number of institutions will not. The reasons for these policies were not elicited. Most respondents did not have a policy requiring washing beyond a specified number of days of storage or days after irradiation. Since RBCs stored for prolonged periods of time after irradiation have increased plasma potassium, it is important to develop policies to prevent clinically significant posttransfusion hyperkalemia in at-risk patients when RBCs are irradiated and not used immediately. More work still needs to be done to resolve these fundamental precepts of neonatal transfusion.

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.

Hemorrhagic Shock

Hemorrhagic shock has been studied extensively in the adult population, but evidence is lacking in the pediatric population. Unlike adults, pediatric patients tolerate hypovolemia with less hypotension until they have reached significant blood volume loss. It is imperative they receive prompt intravenous access, crystalloid resuscitation, followed by blood product transfusion. A hemoglobin goal of 7 g/dL has been translated to the pediatric population without evidence of poor outcomes. Massive transfusion protocols involving a 1:1:1 ratio of red blood cells:fresh frozen plasma:platelets has been recommended although further evidence is needed. With the transfusion of multiple blood products, consideration must be taken into account for the side effects, including electrolyte imbalance and lung injury.

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.

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.