In this video, we demonstrate how to perform autotransfusion. The dog in this video sustained severe internal crushing injuries to the chest and abdomen from being rolled over by both the front tire and back tire of a vehicle. This resulted in massive hemorrhage into the thoracic and abdominal cavities, hypovolemic shock (lactate on arrival: 12.9 mmol/L), and respiratory distress. She was stabilized using the autotransfusion of a total of ~4L of blood (~2.3L from the chest and ~1.7L from the abdomen); this constituted approximately 250% of the patient’s entire blood volume, which was calculated at 1.6L. Under our care, the patient also received supplemental oxygen, analgesia (fentanyl), intravenous fluids (Normosol-R), and two units of canine fresh frozen plasma ( to address consumptive coagulopathy). Once the patient was stabilized for transport, she was transferred to a referral center for ongoing care. There, she also received additional blood products (homologous/allogenic pRBC, whole blood, fresh frozen plasma) and tranexamic acid, a medication that helps to stabilize clot formation. The hemorrhage ultimately stopped without surgical intervention. The patient made a complete recovery, and one month later she was back to going for 3 hour hikes in the mountains.
Overview and considerations:
Autotransfusion is a life-saving technique where a patient with internal bleeding receives a blood transfusion using its own blood. Whole blood that has accumulated within the pleural, abdominal or pericardial space can be aseptically collected and then administered back to the patient through a blood transfusion set. This technique is called autotransfusion, but is sometimes referred to as blood salvage or autologous blood transfusion.
Autotransfusion is especially useful in rural settings. Where I practice, there is very limited access to blood products and we are 1.5 hours from the nearest referral center. I have successfully used this technique to stabilize numerous patients with life-threatening internal bleeding from a variety of causes, including trauma, surgical complications, coagulopathy and hemangiosarcoma. Due to the very critical nature of these cases, our goal is usually to stabilize them so that they can be safely transported to the nearest referral center/ ICU for ongoing 24 hour critical care.
Autotransfusion can be used to maintain cardiovascular stability while waiting for the hemorrhage to resolve, or to optimize patient stability so that the site of hemorrhage can be addressed surgically.
I think of ongoing hemorrhage like a bucket of water with a hole in it. If all the water drains out, the fish in the bucket will die; likewise if all of the blood drains out of the circulation, the patient will die. Autotransfusion is like collecting the water coming out of the hole in the bottom of the bucket, and then pouring it back into the bucket so that the water level in the bucket remains stable. Obviously, if the hole doesn’t get patched (if the bleeding doesn’t stop), then you will be there all day… or worse.
Autotransfusion can only be performed using blood resulting from pure internal hemorrhage. You must confirm that an effusion is purely hemorrhagic, and that the blood is not mixed with other types of fluid that can also accumulate within body cavities (urine, bile, septic fluid, etc) . This is done by comparing the PCV of the effusion to the peripheral blood; with a purely hemorrhagic effusion, the PCV of the fluid will be GREATER THAN OR EQUAL TO that of the peripheral blood.
Adverse effects of autotransfusion:
In human medicine, autotransfusion has been found to be associated with a higher rate of DIC and mortality, and so when available in sufficient quantities, homologous/allogenic blood product transfusion (transfusion of blood from a compatible donor) is usually preferred.
When we are performing autotransfusion, it is usually with the goal to stabilize the patient until it can be transferred to a referral center where there is better access to donor blood products.
How to Perform Autotransfusion: Step by Step
Perform a focused ultrasound to identify the site(s) of internal bleeding.
A quick ultrasound scan of the body cavities (abdomen, thorax, and pleural space) looking for the presence of free fluid is an important part of the routine assessment of emergency patients, especially trauma patients.
To learn more about focused ultrasound for cavitary effusion, also called FAST (focused assessment with sonography for trauma), visit this post (How to perform a focused ultrasound for cavitary effusion).
Perform diagnostic centesis (obtain a sample of the fluid for testing). Also perform therapeutic centesis (drain the fluid to alleviate respiratory distress or tamponade) if indicated:
When dealing with abdominal effusion, I will usually perform a simple diagnostic abdominocentesis using a needle and syringe, with the goal of obtaining enough sample to test the fluid. Ultrasound guidance is preferred but not necessary.
If the patient has pleural effusion and is dyspneic, then I will do both diagnostic centesis (obtain enough sample for testing) and therapeutic centesis (continue to drain as much of the fluid as possible to alleviate respiratory distress) at the same time. Similarly, if the patient has significant pericardial effusion and is clinical for this, I will perform both diagnostic and therapeutic centesis.
If an effusion looks hemorrhagic, as a general rule, I collect the fluid into sterile 60 cc syringes using aseptic technique, and keep these close by in case the fluid is pure blood and is needed for autotransfusion.
Collect the blood into sterile 60cc syringes using aseptic technique.
If you are dealing with a patient that has internal bleeding, it helps to have continuous access to the source of pooling blood. Placing a catheter or tube through the skin and into the site where the blood is pooling is the easiest way to continue draining the fluid.
Here are some techniques you may need depending on where the fluid is.
- How to perform abdominocentesis. This explains how to perform diagnostic and therapeutic abdominocentesis as welll as how to place an abdominal catheter.
- How to perform pericardiocentesis.
- How to perform thoracocentesis.
- How to place a MILA chest tube.
If the patient is undergoing abdominal or thoracic surgery and the blood is directly accessible, you can gently suction the blood directly from the body cavity using aseptic technique. You may choose to use a 60 cc syringe attached to a fenestrated red rubber catheter or you may choose to use a pool suction tip on a low suction setting.
Ensure that the effusion is purely hemorrhagic (pure blood)
You need to test the effusion to make sure that it is pure blood and not mixed with other types of fluid (such as urine, bacteria/septic fluid, bile, etc). Compare the PCV of the effusion to the PCV of the peripheral blood. The PCV of the effusion should be greater than or equal to the PCV of the peripheral blood.
Administer the blood back to the patient intravenously through a blood transfusion filter:
Take the blood that you aseptically collected from the body cavity and administer it IV to the patient through a blood transfusion filter. For the first few syringes, I will inject the blood through an 18 micron hemonate filter, which is a small filter that screws directly into the IV fluid line. They are inexpensive and available from most veterinary suppliers.
For larger volumes of blood, I will transfer the blood into an empty IV fluid bag and run the fluid through a blood administration set . To transfer the fluid into the empty fluid bag, I will usually inject it through the bag’s injection port using an 18 ga needle. Some prefer to cut a corner off the top of the bag (keeping that corner rolled over and clamped when not in use).
Blood collected into a syringe can be administered back to the patient intravenously through a hemonate blood filter. You do not need to mix the blood suctioned from a body cavity with an anticoagulant such as CPDA.
Repeat as needed:
For larger volumes of blood, I will transfer the blood into an empty IV fluid bag and run the fluid through
Recognizing and treating coagulopathy to curtail ongoing hemorrhage
Fresh Frozen Plasma for Consumptive Coagulopathy
In the actively hemorrhaging patient, it is wise to check blood clotting times ASAP and to monitor clotting times closely if the bleeding continues. If clotting times are significantly prolonged, fresh frozen plasma will likely be needed to restore clotting factors. Many patients with significant ongoing hemorrhage will develop a consumptive coagulopathy, where so many clotting factors are consumed that the blood can no longer clot effectively. With active hemorrhage and prolonged clotting times, the bleeding will probably not stop until the coagulopathy has been addressed.
Monitoring for transfusion reactions when administering FFP:
- Monitor temperature, heart and respiratory rate ate time 0 (prior to starting the transfusion) and then every 10-15 minutes for the first half hour.
- If no issues have arisen then check half hourly until an hour after the transfusion has been completed.
Recommended dosages for dogs (from PetBloodBankUK.org)
- Fresh Frozen Plasma:
- volume: 20 mg/kg
- initial transfusion rate of 0.5-1.0 ml/kg/hour for 20-30 minutes is appropriate with close observation of the patient for any signs of an adverse reaction.
- If no reaction is observed the remaining plasma can be given over the next 3-4 hours.
- during emergency (coagulopathy + ongoing hemorrhage):
- volume: 20 mg/kg IV;
- rate: “In an emergency situation, the risk and consequences of a transfusion reaction need to be weighed against the benefits of giving the plasma rapidly. If the situation demands, the whole transfusion can be given over a 20-30 minute period. The patient must be closely monitored during this time and equipment and drugs necessary for dealing with a transfusion reaction, should it occur, be immediately available.” (from PetBloodBankUK.org)
Tranexamic acid (TXA) and Epsilon aminocaproic acid (EACA): These are medications that help to stabilize blood clots (by inhibiting fibrinoloysis), and are widely used in human hospitals to help stop bleeding. While relatively new (and off-label) in veterinary medicine, TXA and EACA are becoming more popular in the ER. We were able to order TXA for IV injection from our local pharmacist and it was relatively inexpensive.
Recommended dosages for dogs (from DVM360)
- Tranexamic acid (TXA):
- active bleeding: 50 to 100 mg/kg orally or intravenously every six hours.
- Greyhounds undergoing surgery: 50 to 100 mg/kg orally or intravenously every six hours.
- Epsilon aminocaproic acid (EACA):
- active bleeding: 10 -15 mg/kg IV over 20 minutes followed by CRI of 1 mg/kg/h for 6-10 hours
Yunnan Baiyao: Yunnan Baiyao is a traditional Chinese herbal supplement that has been used in people for more than a century to control bleeding, particularly that resulting from war and combat situations. Numerous human and in vitro studies indicate that Yunnan Baiyao promotes hemostasis. Veterinary research supporting Yunnan Baiyao’s efficacy is limited, but it is generally believed to be safe.
- Recommended dosages for dogs and cats (from MSPCA Angell):
- 1 capsule (0.25 grams) per 20 lbs orally TID-BID.
Surgical intervention for internal hemorrhage:
A patient has developed hemoabdomen with active/ongoing hemorrhage within 48 hours of abdominal surgery or neuter, it is generally advised that surgical exploration and intervention are indicated once the patient’s stability and clotting times are optimized. The same can be said if a patient develops hemothorax within 48 hours of thoracic surgery.
Internal bleeding (hemoabdomen, hemothorax) often resolves without surgical intervention in patients that have experienced trauma, as long as there is no concurrent coagulopathy. Surgical exploration may be needed if there is significant unrelenting active internal hemorrhage.