Effect of varying external pneumatic pressure on hemolysis and red blood cell elongation index in fresh and aged blood: Randomized laboratory research

Evaluation of erythrocyte membrane oxidation due to their exposure to shear flow generated by extracorporeal blood pump

Several similarities have been found between shear stress-induced erythrocyte damage and physiological aging of erythrocytes in terms of elevated mechanical fragility, increased erythrocyte aggregation, and decreased membrane surface charge. Accordingly, we hypothesized that blood pump circulation, which generates shear stress, would accelerate erythrocyte aging, manifesting as oxidation. Therefore, the purpose of this study was to investigate the effect of blood pump circulation on erythrocyte oxidation. Fresh porcine blood was acquired from a slaughterhouse and anticoagulated with sodium citrate. About 500 mL of anticoagulated whole blood was circulated for 180 min in an in vitro test circuit comprising a BP-80 blood pump with a pump speed and a pump pressure head of 100-120 mmHg. A blood sample was taken at the start of the circulation and 180 min afterward. The hemolysis level and oxidation amount of the erythrocyte membrane were analyzed and compared between samples. Hemolysis increased with the prolongation of shear exposure inside the pump circuit. After 180 min of blood pumping in circuit, the oxidation level of the erythrocyte membrane showed an increase of 0.1 nmol/mg protein. Moreover, the membrane oxidation levels of sheared erythrocytes were greater than those of control erythrocytes. These results suggest that blood pump circulation accelerates erythrocyte aging and give us a greater understanding of the effects of blood pump perfusion.

Transfusion Practice: Hemolysis Markers After In Vitro Infusion of Packed Red Blood Cells by the Gravitational Method in Peripheral Catheter

The objective of this study was to compare hemolysis marker levels after in vitro infusion of red blood cells (RBCs) according to storage time, infusion rate, and peripheral intravenous catheter size. This is an experimental study with randomly administered RBCs in quintuplicate, according to storage time shorter than and longer than 14 days, as well as infusion rate (50 mL/h and 100 mL/h) using catheters with calibers of 14-, 18-, and 20-gauge. Aliquots were collected from RBCs (V1), after equipment and catheter (V2) free-flow filling and after controlled infusion through the catheter (V3). The hemolytic markers analyzed were degree of hemolysis (%), hematocrit (Ht) (%), total hemoglobin (THb) (g/dL), free hemoglobin (FHb) (g/dL), potassium (K) (mmol/L), and lactate dehydrogenase (LDH) (U/L), considering a probability of error ≤5%. Sixty experiments were performed with the analysis of 180 aliquots. When RBCs aged <14 days were used, all catheters tended to increase THb, FHb, and K; while >14 days, RBCs presented increased FHb and degree of hemolysis with catheters of 18-gauge and THb levels at 14-gauge. Among the conditions analyzed, only 20-gauge catheters (the smallest) did not influence changes in hemolysis markers, regardless of RBC storage time.

Evaluation of a rail logistics transmission system for the transportation of blood components within a medical centre

BACKGROUND AND OBJECTIVES

Rail logistics transmission systems (RLTSs) are commonly used for the transportation of blood samples, pathological specimens and other medical materials in many hospitals, as they are rapid, secure, cost-effective and intelligent. However, few studies have evaluated blood component transportation from blood banks to the patient care areas of hospitals using RLTS. In this study, we evaluate the RLTS used for the transportation of blood components within a medical centre.

MATERIALS AND METHODS

The dispatch of blood components, including packed red blood cells (pRBCs), fresh frozen plasma (FFP), cryoprecipitate and platelet units, from a blood bank to critical care areas or general wards was done using RLTS. Parameters such as the delivery time, temperature, physical integrity and blood component quality were evaluated via analytical testing using specimens obtained before and after transportation by RLTS.

RESULTS

The turnaround time and temperature of all tested blood units via RLTS transportation were able to meet the clinical demands of blood component delivery (median time: 323 s [118-668 s]; temperature variation: 4.5-8.9°C for pRBCs and FFP and 21.5-23.5°C for cryoprecipitate and platelet units). Furthermore, parameters of pRBC quality, including the haemolysis index and potassium and lactate dehydrogenase levels in plasma, were not significantly different before and after transportation through RLTS. Similarly, RLTS transportation affected neither the basic coagulation test results in FFP and cryoprecipitate specimens nor platelet aggregation and activation markers in apheresis platelet specimens.

CONCLUSION

Hospital-wide delivery of blood components via RLTS seems to be safe, reliable and cost-effective and does not have any negative impact on blood quality. Therefore, the establishment of standard criteria, protocols and guidelines based on further studies is needed.

Influence of Peripherally Inserted Central Catheters With Proximal Valves on Red Blood Cell Hemolysis During Transfusion

The aim of this study was to verify the occurrence of hemolysis after infusion of packed red blood cells (PRBCs) in 12 peripherally inserted central catheters (PICCs) with a proximal valve, according to size and infusion rate. This was an experimental in vitro study performed under laboratory-controlled conditions, and the sample was composed of 12 PICCs with proximal valves (3F and 4F catheter). Twelve type A+ aliquots from 10 PRBCs were analyzed preinfusion and postinfusion according to PICC size and infusion rate. Hemolysis markers, total hemoglobin (g/dL), hematocrit (%), free hemoglobin (g/dL), potassium (mmol/L), lactate dehydrogenase (U/L), and rate of hemolysis (%) were studied. Data were analyzed using analysis of variance and Bonferroni multiple comparison tests. After the infusions in 3F PICCs, an increase was seen in rate of hemolysis (P = .003) and free hemoglobin (P = .014), in addition to a reduction in total hemoglobin (P = .002), with significant influence of minimum and maximum flow rates on the rate of hemolysis. The study finding indicated that the smaller catheter size and the infusion rate influenced variations in some hemolysis markers, but the alterations observed in the hemolysis markers would not contraindicate the infusion of PRBCs by 3F and 4F PICCs with proximal valves.

Tidal Flow Perfusion for the Artificial Placenta: A Paradigm Shift

The modalities of vascular access for the extracorporeal artificial placenta (AP) have undergone many iterations over the past decade. We hypothesized that single lumen cannulation (SLC) of the jugular vein using tidal flow extracorporeal life (ECLS) support is a feasible alternative to venovenous (VV) umbilical-jugular cannulation and double lumen cannulation (DLC) and can maintain fetal circulation, stable hemodynamics, and adequate gas exchange for 24 hours. After in vitro evaluation of the tidal flow system, six preterm lambs at estimated gestational age 118-124 days (term 145 days) were delivered and underwent VV-ECLS. Three were supported using DLC and three with SLC utilizing tidal flow AP support. Hemodynamics, circuit flow, and gas exchange were monitored. Target fetal parameters were as follows: mean arterial pressure 40-60 mmHg, heart rate 140-240 beats per minute (bpm), SatO2% 60-80%, PaO2 25-50 mmHg, PaCO2 30-55 mmHg, oxygen delivery >5 ml O2/dl/kg/min, and circuit flow 100 ± 25 ml/kg/min. All animals survived 24 hours and maintained fetal circulation with stable hemodynamics and adequate gas exchange. Parameters of the tidal flow group were comparable with those of DLC. Single lumen jugular cannulation using tidal flow is a promising vascular access strategy for AP support. Successful miniaturization holds great potential for clinical translation to support extremely premature infants.