Four-dimensional temperature distributions in red blood cells withdrawn from storage and exposed to ambient temperature: a magnetic resonance thermometry study

Monitoring of Storage and Transportation Temperature Conditions in Red Blood Cell Units: A Cross-Sectional Study

The process of storage and transportation of the red blood cells (RBCs) out of the standard temperature range lead to some biochemical reactions. Infusing inappropriately stored RBCs may cause severe complications. The main objective of this study was to investigate the RBC bags' temperature during the transfusion chain including storage, transportation, and transfusion. A cross-sectional study was performed on 100 RBC bags that were sent from the blood bank to the cardiac surgical intensive care unit (CSICU) and the operating room (OR). To record the temperature of RBCs, a temperature monitoring device was attached to each bag of RBCs that were transported from the blood bank to the CSICU and the OR. The stored temperature samples in the devices related to different stages were separated. Finally, the normal and non-normal samples of each phase were segregated based on the current guidelines. The results indicated that 10% of 121,262 recorded temperatures samples (per 2 min) were out of the standard range. Of these, 65, 17, 13, and 5% of samples were related to the blood bank, the OR, transportation, and the CSICU, respectively. The minimum and maximum temperatures were 0 °C and 19.5 °C that were below and above the standard, respectively. In the light of findings of the present study, different stages of blood transportation and storage suffer a number of shortcomings, which are more evident in the blood bank. Thus, it is recommended to better manage blood transfusion chain from the blood bank to hospital wards so as to avoid the inadvertent and undesirable consequences of blood transfusion. Because various judgments made by the personnel about the status of blood bags are subjective, a temperature monitoring device can be employed to better monitor the blood transfusion process and compensate for the errors unnoticed by the personnel.

Logistical and safety implications of temperature-based acceptance of returned red blood cell units

BACKGROUND

AABB requires that red blood cells (RBCs) are maintained at 1 to 10°C during transport. Historically, blood banks used the 30-minute rule for returned RBCs transported outside of validated containers. The implications of this policy have not been previously reported in a real-life hospital setting.

STUDY DESIGN AND METHODS

A 2-year, retrospective review of RBC units returned outside of qualified containers was conducted. During the first year, the 30-minute rule was used to accept RBCs back into inventory. Sequentially, the following year, a temperature-based approach was implemented using a thermometer with an accuracy of ±1°C. Time out of the blood bank, temperature upon return, wastage, and transfusion reactions associated with the reissued RBCs were analyzed.

RESULTS

In our practice, the 30-minute rule would have accepted 15.2% of RBC units outside of the allowed temperature. Compared to the 30-minute rule, temperature-based acceptance was associated with a 13% increase in wastage (p < 0.001). During the 30-minute rule period, transfusion of returned and subsequently reissued RBCs was associated with a nonsignificant trend toward a higher transfusion reaction rate compared to the overall RBC transfusion reaction rate (1.4% vs. 0.6%, p = 0.084). During the temperature period, transfusion of returned and subsequently reissued RBCs had the same transfusion reaction rate compared to the overall RBC transfusion reaction rate (0.5% vs. 0.5%, p = 1.0).

CONCLUSION

Temperature-based acceptance of returned RBCs is associated with significantly higher wastage compared to the 30-minute rule. A temperature-based acceptance practice mitigates the risk of accepting RBCs with unacceptable temperatures returned within 30 minutes of issue.

Temperature-Sensitive Indicators for Monitoring RBC Concentrates Out of Controlled Temperature Storage

OBJECTIVES

The 30-minute rule for RBC concentrates out of controlled temperature storage does not take into account multiple parameters that influence warming of RBC concentrates. This study evaluated two temperature-sensitive indicators (TIs) for monitoring RBC concentrates during transport.

METHODS

TI labels (Check-Spot [Harald H. Temmel KG, Gleisdorf, Austria] and Thermoindikator V4 [BASF, Basel, Switzerland]) were attached to RBC concentrates prior to delivery. Duration of transport, ambient temperatures, and label results (valid vs expired) were recorded. We evaluated the proportion of labels discrepant to the 30-minute rule overall and among deliveries 30 minutes or less and more than 30 minutes and compared the rates of valid and expired readings between both TIs.

RESULTS

In total, 201 RBC concentrate deliveries (86.6%) lasted 30 minutes or less, and 31 (13.4%) were more than 30 minutes. Forty-six (19.8%) Check-Spot and 37 (15.9%) Thermoindikator V4 results were discrepant to the 30-minute rule. Sixteen (51.6%) and 27 (87.1%) RBC concentrate deliveries more than 30 minutes displayed valid label readings with Check-Spot and Thermoindikator V4, respectively. Rates of expired labels among deliveries 30 minutes or less and valid labels among deliveries more than 30 minutes differed significantly between TIs (P < .01).

CONCLUSIONS

TIs identified a considerable number of RBC concentrates whose temperatures may not be adequately reflected by the 30-minute rule. Variability of readings between TIs stresses the necessity of validation prior to implementation.

Impact of constant storage temperatures and multiple warming cycles on the quality of stored red blood cells

BACKGROUND

Red blood cells (RBCs) are routinely stored in liquid state at temperatures below 6°C, and RBC unit core temperature should not exceed 10°C during transport. Since the critical temperature of 10°C was chosen mostly arbitrarily, this study investigated the effect of both constant temperature settings as well as multiple rewarming cycles on stored RBCs with respect to morphology, biochemical parameters and haemolysis.

MATERIALS AND METHODS

Buffy coat-depleted filtered RBCs were used as standard products. RBCs were stored at 1-6°C (reference group, n = 12), 13 and 22°C (test groups, n = 12 each) or stored at 1-6°C and warmed up five times to 10, 13, or 22°C for a period of 24 h each. Various biochemical parameters were measured weekly. RBCs were further investigated using electron microscopy.

RESULTS

Red blood cells stored constantly at 13 or 22°C showed stable haemolysis rates until day 28 and day 14, respectively. RBCs stored at 1-6°C with five warming-up periods to 10, 13 or 22°C each lasting 24 h (total 120 h) did not exceed the limit of the haemolysis rate at the end of storage. Differently shaped erythrocytes were found in all samples, but more crenate erythrocytes appeared after 42 days of storage independent of temperature profiles.

CONCLUSION

Red cells can be kept at constant temperatures above 6°C without apparent harmful effects at least until day 14, whereas multiple warming cycles for no longer than 24 h at 10, 13 or 22°C with subsequent cooling do not cause quality loss as assessed using the in vitro assays employed in this study.

Thermometry of red blood cell concentrate: magnetic resonance decoding warm up process

PURPOSE

Temperature is a key measure in human red blood cell concentrate (RBC) quality control. A precise description of transient temperature distributions in RBC units removed from steady storage exposed to ambient temperature is at present unknown. Magnetic resonance thermometry was employed to visualize and analyse RBC warm up processes, to describe time courses of RBC mean, surface and core temperatures by an analytical model, and to determine and investigate corresponding model parameters.

METHODS

Warm-up processes of 47 RBC units stored at 1-6°C and exposed to 21.25°C ambient temperature were investigated by proton resonance frequency thermometry. Temperature distributions were visualized and analysed with dedicated software allowing derivation of RBC mean, surface and core temperature-time courses during warm up. Time-dependence of mean temperature was assumed to fulfil a lumped capacitive model of heat transfer. Time courses of relative surface and core temperature changes to ambient temperature were similarly assumed to follow shifted exponential decays characterized by a time constant and a relative time shift, respectively.

RESULTS

The lumped capacitive model of heat transfer and shifted exponential decays described time-dependence of mean, surface and core temperatures close to perfect (mean R(2) were 0.999±0.001, 0.996±0.004 and 0.998±0.002, respectively). Mean time constants were τmean = 55.3±3.7 min, τsurface = 41.4±2.9 min and τcore = 76.8±7.1 min, mean relative time shifts were Δsurface = 0.07±0.02 and Δcore = 0.04±0.01. None of the constants correlated significantly with temperature differences between ambient and storage temperature.

CONCLUSION

Lumped capacitive model of heat transfer and shifted exponential decays represent simple analytical formulas to describe transient mean, surface and core temperatures of RBC during warm up, which might be a helpful tool in RBC temperature monitoring and quality control. Independence of constants on differences between ambient and storage temperature suggests validity of models for arbitrary storage and ambient temperatures.