
This post was written by Gabriella Alvarado, BSc, MLT. [CANADA] Medical Laboratory Technologists (MLTs) are most similar, professionally, to other global scientists such as Biomedical Scientists, Medical Technologists, and Medical Laboratory Scientists.
One of the many responsibilities delegated to Medical Laboratory Technologists (MLTs) in Transfusion Medicine is the preparation and cross-matching of blood products. MLTs may be involved in cases where the patients have traumatic bleeding or a chronic hemoglobinopathy condition. Working in a pediatric hospital is a specialty all on its own, as age and weight of a patient determines what type of blood product can be safely given. It was surprising to learn that packed red blood cells and platelets can be divided into smaller units for pediatric patients. However, I was most surprised to learn the pivotal role MLTs have when a patient goes on ECMO.
Extracorporeal membrane oxygenation (ECMO) is a form of life-support that providers may consider when current treatment plans are not working (American Thoracic Society, 2020). A tube is connected to an artery or vein and the patient’s blood is pumped into an oxygenator (American Thoracic Society, 2020). Oxygen is added and carbon dioxide removed before recirculating back into the patient (American Thoracic Society, 2020). This bypass method allows the heart and lungs to heal in hopes of making the patient strong enough to continue with treatment (American Thoracic Society, 2020). Due to the artificial nature of ECMO, the procedure requires administration of anti-coagulant medications to prevent clotting (American Thoracic Society, 2020). As a result, the patient is at risk for bleeding and ECMO-induced hemolysis (American Thoracic Society, 2020) (Williams et al., 2015).
Communication is one of the most important elements to ensure the patient is smoothly transitioned onto ECMO. The laboratory effectively prepares for the increase in blood products that an ECMO patient will most likely consume. Additionally, it is equally as important to check blood product stock supplies, order additional blood specific products, and ensure a current 96-hour sample is on file. Consistent communication will allow the laboratory to prioritize product preparation and help avoid any delays in transfusing.
The first few hours after a patient is placed on ECMO can be stressful but quite adrenaline filled The mechanical nature of ECMO destroys red blood cells and decreases platelet numbers (Williams et al., 2015). As a result, a CBC test is frequently ordered to monitor hemoglobin and platelet levels. As the patient adjusts to ECMO, a significant amount of packed red blood cells, platelets, and plasma may be required. Therefore, obtaining the following information can assist the MLT:
- How many milliliters of packed RBC should be crossmatched at all times?
- Is irradiated blood required?
- Are pooled or apheresis platelets required?
- Should plasma be thawed ahead of time or will the floor notify in advance when it is required?
Lastly, the MLT must decide how often to either replenish or increase stock supplies. The decision should be based on frequency of product usage, product availability from the Canadian Blood Services (the national blood authority), and preferred product type. For example, if group specific apheresis platelets are unavailable would the perfusionist prefer:
- (1) out of group plasma reduced platelets – this requires an additional 1 hour of sitting before being available to transfuse
- (2) group compatible pooled platelets
- (3) wait until group specific apheresis platelets are available
The MLT critically analyzes all these feasible options and relays which option(s) best fits the perfusionist requirements. The MLT will also consider the age and weight of the patient when offering options. For instance, neonates under 4 months of age or patients under 20kg cannot be transfused with psoralen-treated platelets (irritated equivalent). However, a hematopathologist may sign off if the patient is so critically ill that receiving any platelets is better than nothing.
My first experience overseeing an ECMO patient makes preparation of blood products for chronically transfused patients or up-coming ORs relatively routine in comparison. A patient’s response to ECMO may not always be predictable, forcing an MLT to base decisions in a grey area of potential ‘what-ifs’. As a new MLT, this can be incredibly challenging as I have no previous experience to rely on to assist in such decision making. However, I took it as an opportunity to reflect and ask my co-workers of their previous experience. I compared their decisions against mine to identify where I could improve upon. If your mistakes don’t compromise patient care; use them as an opportunity to improve your clinical skills rather than shy away from challenging situations.
References
American Thoracic Society.2020. Patient Information Series-What is ECMO? Thoracic. Retrieved from https://www.thoracic.org/patients/patient-resources/resources/what-is-ecmo.pdf
Williams, D.C., Turi, J.L., Hornik, C. P., Bonnadonna, D.K., Willford, W.L., Walczak, R.J., et al.Watt, K.M., CHeifetz, I.M. 2015. Circuit Oxygenator Contributes to Extracororeal Membrane Oxygenation-Induced Hemolysis.PMC, 61(2), 190-195. Doi https://dx.doi.org/10.1097/MAT.0000000000000173