Split red blood cell units contain defined extracellular K+ levels, which are improved by a washing procedure
Fabiola Hoppe1, Jacqueline Maier1, Holger Kirsten2
1Institute of Transfusion Medicine, Faculty of Medicine, Leipzig University, Leipzig, Germany.
Insights
Washing red blood cells (RBCs) with or without irradiation by day 8 significantly reduces potassium levels, crucial for neonatal transfusions. This washing method may extend RBC shelf life by 48 hours while maintaining safety.
Area of Science:
- Transfusion Medicine
- Blood Banking
- Pediatric Hematology
Background:
- Massive transfusion of red blood cells (RBCs) in children requires control of extracellular potassium (K+) levels.
- Current guidelines recommend using RBCs stored for a maximum of 7 days to manage hyperkalemia.
- High K+ levels in stored RBCs pose a risk, especially in neonates.
Purpose of the Study:
- To evaluate the efficacy of a washing procedure for saline-adenine-glucose-mannitol (SAGM) stored RBCs.
- To determine the impact of washing and gamma irradiation on K+ levels, RBC quality, and storage duration.
- To assess if these interventions can reduce supernatant K+ and potentially extend RBC shelf life.
Main Methods:
- Red blood cells (240-330 mL) were stored in SAGM solution for 21 days at 4°C.
- RBC units were split and washed on day 1 or day 8 of storage.
- Some units were gamma-irradiated on day 8; K+, glucose, lactate, lactate dehydrogenase (LDH), adenosine triphosphate (ATP), and hemolysis were measured over 21 days.
Main Results:
- Washing on day 1 improved glucose and lactate levels.
- Washing on day 8 improved LDH and K+ levels.
- Irradiation accelerated K+ accumulation and increased hemolysis; washing post-irradiation significantly reduced K+ levels (1.12 mM vs. 21.2 mM on day 8).
- K+ concentrations remained below 25 mM within 8 days of storage.
Conclusions:
- Irradiation of RBCs should be performed by day 8 at the latest for neonatal transfusions.
- Washing RBCs, particularly after irradiation, effectively reduces K+ levels.
- Combining washing with irradiation may extend the usable shelf life of RBCs by an additional 48 hours.
Background And Objectives:
We should control free K+ during massive transfusion (>80 mL/kg) of red blood cells (RBCs) in small children. To manage this, several national and international guidelines recommend using RBCs stored only up to 7 days. We tested a washing step for RBCs in saline-adenine-glucose-mannitol (SAGM) with or without irradiation to reduce supernatant K+ levels, improve quality and potentially extend the shelf life of stored RBCs.
Materials And Methods:
RBCs of 240-330 mL were prepared from whole blood donations, then split into halves and stored in SAGM solution at 4 ± 2°C for 21 days. RBCs were split and washed on Days 1 and 8, and some were gamma-irradiated on Day 8. Glucose, lactate, lactate dehydrogenase (LDH), adenosine triphosphate (ATP), K+ and haemolysis were determined over 21 days.
Results:
After washing on Day 1, only glucose and lactate improved, whereas after washing on Day 8, LDH and K+ also improved. Irradiation resulted in accelerated K+ accumulation and increased haemolysis. Mean extracellular K+ concentrations were 21.2 ± 1.03 mM after irradiation on Day 8 versus 1.12 ± 0.05 mM after irradiation plus wash on Day 8, and 38.80 ± 2.13 mM on Day 10 after irradiation on Day 8 and 16.6 ± 0.05 mM on Day 10 after irradiation plus wash on Day 8.
Conclusion:
K+ concentrations remained <25 mM within 8 days of storage. We recommend irradiation by Day 8 at the latest for neonatal transfusion. The shelf life may be extended by another 48 h if the RBCs are also washed.
