A 5-year-old boy was playing with his older brother in front of their home when he was struck by a car. He sustained a femur fracture, splenic laceration, and blunt head trauma – the so-called Waddell’s triad.
On arrival, he was in compensated shock, with tachycardia. He needs blood.
He decompensates…
How do we manage his hemodynamics and when do we perform massive transfusion?
Pediatric Massive Transfusion
40 mL/kg of blood products given at any time within the first 24 hours.
Adolescents and Adult Massive Transfusion
6-8 units of packed red blood cells (PRBCs)
- Adults have about 5 L of circulating blood.
- Not including plasma, one could replace all circulating erythrocytes with about 10 units of PRBCs
- The best ratio of PRBCs:Plasma:Platelets is unknown, but consensus is 1:1:1.
- 1 unit of PRBCS is typically 300 mL of volume.
The typical initial transfusion of PRBCs in children is 10 mL/kg.
Massive transfusion in children is defined as 40 mL/kg of any blood product.
Once you start to give a child with major trauma the second 10 mL/kg dose of PRBCs – start thinking about other blood components, and ask yourself whether you should initiate your massive transfusion protocol.
The goal is to have the products ready to use in the case of the dynamic trauma patient.
The Thromboelastogram (TEG)
TEG directly measures the four components of clot formation. When there is endolethial damage and bleeding, the sequence that your body takes to address it is as follows:
- Platelets migrate and form a plug
- Clotting factors aggregate and reinforce the platelets
- Fibrin arrives an acts like glue
- Other cells migrate and support the clot.
R time – reaction time – the initial line in the tracing that shows time to beginning of clot formation.
- Treated with platelets
K factor – kinetics of the clot –how much the clot allows the pin to move, or the amplitude.
- Treated with cryoprecipitate
Alpha angle – the slope between the R and K measurements – reflects how quickly the fibrin glue is working.
- Treated with cryoprecipitate
Ma – maximum amplitude – reflects the overall strength of the clot.
- Treated with platelets
LY30 – the clot lysis at 30 min – is the decrease in strength of the clot’s amplitude at 30 min.
- Treated with an antifibrinolytics (tranexamic acid)
Shape Recognition
Red wine glass: a normal tracing with a normal reaction time and a normal amplitude. That patient just needs support and monitoring.
Champagne glass: a coagulopathic TEG tracing – thinned out, with less amplitude. This patient needs specific blood products.
Puffer fish or blob: a hyperfibrinolytic tracing. That patient will needs clot-stablizer.
TEG – like the FAST – can be repeated as the clinical picture changes.
The Trauma Death Spiral
Lethal triad of hypothermia, acidosis, and coagulopathy.
Keep the patient perfused and warm.
Each unit of PRBCs contains 3 g citrate, which binds ionized calcium, causing hypotension. In massive transfusion, give 20 mg/kg of calcium chloride, up to 2 g, over 15 minutes. Calcium chloride is preferred, as it is ionically readily available – just use a larger-bore IV and watch for infiltration. Calcium gluconate could be used, but it requires metabolism into a bioavailable source of calcium.
Prothrombin complex concentrate (PCC)
Prothrombin complex concentrate (PCC) is derived from pooled human plasma and contains 25-30 times the concentration of clotting factors as FFP. Four-factor PCCs contain factors II, VII, IX and X, while 3-factor PCCs contain little or no factor VII.
The typical dose of PCC is 20-50 units/kg
In the severely hemorrhaging patient – you don’t have time to wait for the other blood products to thaw – PCC is a powder that is reconstituted instantly at the bedside.
Tranexamic acid (TXA)
Tranexamic acid (TXA), is an anti-fibrinolytic agent that functions by stopping the activation of plasminogen to plasmin, and the degradation of fibrin. The Clinical Randomisation of an Antifibrinolytic in Significant Hemorrhage (CRASH-2) investigators revealed a significant decrease in death secondary to bleeding when TXA was administered early following trauma.
Based on the adult literature, one guideline is to give 15 mg/kg loading dose of TXA with a max 1 g over 10 minutes followed by 2 mg/kg/h for at least 8 h or until bleeding stops.
Resuscitative Pearls
Our goal here is damage control. Apply pressure whenever possible. Otherwise, resuscitate, identify the bleeding source, and slow or stop the bleeding with blood products or surgery.
How Children are Different in Trauma
In adults, we speak of “permissive hypotension” (also called “balanced resuscitation” or “damage control resuscitation”). The idea is that if we bring the adult patient’s blood pressure up to normal, we may be promoting clot rupture. To avoid this, we target a MAP of 65 and look for clinical signs of sufficient perfusion. Adults tolerate hypotension relatively well, and is sufficient until we send them to the OR or interventional radiology suite.
In children, this is simply not the case. Hypotension in children is a sign of pre-arrest. Remember, they compensate with an increased systemic vascular resistance and tachycardia to maintain blood pressure.
We should not allow children to become hypotensive – severe tachycardia alone should prompt us to resuscitate.
In other words, permissive hypotension is not permissible for children.
FAST is not sensitive enough to rule-out abdominal trauma.
Fox et al. in Academic Emergency Medicine found a sensitivity of 52%; with a 95% confidence interval [CI] = 31% to 73%.
Often children even with high-grade splenic and liver lacerations can be managed non-operatively. If they are supported adequately, they are observed in the ICU and can avoid surgery in many cases. Unfortunately, a negative FAST cannot help with detecting or grading the laceration for non-operative management. In other words, feel free to use ultrasound – especially for things that we in the ED will react to and intervene on – but CT may help to manage the traumatized child non-operatively.
General Guideline for Imaging in Pediatric Trauma
CT Head and Neck, non-contrast: in concerning mechanisms of injury, patients that are difficult to assess (especially those under 3 months), those with a GCS of 13 or lower.
CT Chest, IV contrast: for suspicion of vascular injury that needs exploration, especially in penetrating trauma. Otherwise, chest xray will tell you everything you need to know in children – especially in blunt trauma. Hemo or pneumothoraces are readily picked up by US or CXR. Rib fractures on CXR predict pulmonary contusions. If you are concerned about great vessel injury, then CT Chest may be helpful; otherwise consider omitting it.
CT Abdomen and Pelvis, IV contrast: helpful in grading splenic and liver lacerations with goal to manage non-operatively. Abdominal tenderness to palpation, significant bruising, or a seat belt sign are concerning and would generally warrant a CT. Also, consider in liver function test abnormalities, or hematuria.
Extremity injuries: in general can be evaluated with physical exam and plain films. However, some injuries in high-risk anatomically complex areas such as the hand and wrist, tibial plateau, and midfoot may be missed by plain films, and CT may be helpful here.
Remember: you can help to mitigate post-traumatic stress and risk for adult healthcare aversion.
Summary
- Massive transfusion in children is at 40 mL/kg of total blood products. Think about it if you are giving your second transfusion to the traumatized child.
- Do everything you can to support perfusion and avoid the death spiral of hypothermia, coagulopathy, and acidosis. Keep the child perfused with blood as needed, correct coagulopathy, avoid too much crystalloid, and make sure to use the least high-tech of all of these interventions – keep him dry and covered with warm blankets.
- Do a careful physical exam, and use CT selectively with an end-point in mind – the default is not the pan-scan – evaluate possible injuries depending on your suspicions from history, physical, and lab tests.
- Become familiar with the relatively new modalities in trauma such as TXA, cryoprecipitate and the emerging technology of thromboelestogram – red wine is good for you, champagne is weak, and a puffer fish is trouble.
Selected References
This post and podcast are dedicated to Larry Mellick, MS, MD, FAAP, FACEP. Thank you for your dedication to medical education, and sharing your warm bedside manner, extensive knowledge and talents, and your patient interactions with the world.
Massive Transfusion on WikEM
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