The traditional use of crystalloid solutions has never included a recommendation of drowning the patient with salt water.Moshe Schein
Last time we have seen the principles of Damage Control Resuscitation (DCR).
With this post, we are going to start explaining the basic treatments you need to apply in order to avoid or reverse the so-called Vicious Cycle.
Consider that each of the following points could be developed much more. However, we want to keep it simple… Few concepts are easier to remember.
Fluids & Permissive Hypotension
Rule number one: traumatized patients are losing blood, not water. Drowning patients is not smart at all.
Crystalloids are to be preferred over colloids. It’s absolutely true that crystalloids shift more into the extraluminal space, causing edema, whereas colloids increase the shift of water from the extraluminal space into the bloodstream, thus increasing more blood volume. However, in shocked patients there may be a loss of the vascular tone, causing a shift of macromolecules to the extraluminal space. This will result in an increase in oncotic pressure in the extraluminal space, calling for water, thus further reducing the circulating volume and worsening hypotension. This is particularly true in patients with septic shock, where the main problem is in the vascular tone. Moreover, colloids may cause acute kidney injury, mainly in patients with preexisting renal failure.
Balanced salt solution (e.g. Ringer’s lactate or acetate) should be preferred over normal saline 0.9%. Normal saline is more acid and it may cause hyperchloremic metabolic acidosis, which worsens the already existing acidosis. Moreover, it was shown by many studies that balanced crystalloids lead to lower rates of death from any cause, renal-replacement therapy, and persistent renal dysfunction, compared to normal saline.
The best way to administer crystalloids is in small boluses, not exceeding 250-500 mL in volume. Moreover, the volume of crystalloids infused should be closely monitored, in order not to give the patients too much “water” (above 1-1.5 L). There are two reasons behind this: not to dilute coagulation factors, and not to increase too much the blood pressure. A traumatized patient, as previously stated, develops coagulopathy. Therefore, it appears difficult to create a thrombus and to stop bleeding. If we keep the SBP close to normal, this will make it more difficult for the patient to stop bleeding.
Remember: it is far more difficult to build a dam in a flooding river than in a quiet one. That’s also the main principle of permissive hypotension.
Moreover, it was shown how each additional 500 mL of crystalloids administered in the first 6 h from admission increases the risk of subsequent acute respiratory distress syndrome. Similarly, crystalloids administration has been linked to the development of multiorgan failure in a dose-dependent manner.
Blood pressure must be targeted depending on the index trauma. Patients who develop hemorrhagic shock after a penetrating trauma are more prone to have an isolated large vessel injury; therefore, lower SBPs are preferable (i.e. 50-70 mmHg). On the other way, shocked blunt trauma patients (i.e. polytrauma patients) usually have multiple organ injuries, most commonly parenchymatous organs (i.e. spleen and liver). In this setting, SBP can be kept slightly higher (i.e. around 80-90 mmHg). A particular case of blunt trauma involves patients with traumatic brain injury. In these patients, a MAP >60-65 mmHg must be targeted. The reason behind this is that TBI patients may develop intracranial hypertension, which impairs cerebral perfusion. Therefore, cerebral perfusion pressure (CPP=MAP-ICP; normal ICP 10-15 mmHg; CPP should be maintained >60 mmHg) must be adequate to avoid brain hypoxia and subsequent ischemic brain injury.
Remember that permissive hypotension is a temporary measure. You cannot keep a traumatized patient hypotensive for all his/her hospital stay, otherwise, he/she will develop hypoxic complications. However, the administration of fluids should be delayed. In fact, early crystalloids resuscitation causes an increased ICU and hospital length of stay.
Fluid therapy may be targeted according to the alleged patients’ fluid responsiveness. This can be evaluated with specific maneuvers, such as passive leg raising (PLR), and ultrasound measurements.
- PLR: measure the patient’s BP, rise the patient’s leg at 30-45°, and wait a couple of minutes, measure again the blood pressure. If there is a 10-12% increase in cardiac output or stroke volume or SBP after PLR, it predicts fluid responsiveness. PLR mimics a fluid bolus of about 500 mL;
- US measurements: measure the inferior vena cava diameter changes during breath cycles at 2-3 cm from the right atrial border. If this change is >12%, it predicts fluid responsiveness. However, this method works well only in mechanically ventilated patients.
However, remember one important thing: the fact that a patient is a fluid responder doesn’t mean he/she needs fluids. Probably, on a normal day, you are fluid responsive, but you don’t need immediate fluids to survive.
Massive Transfusion Protocol (MTP)
A massive transfusion is defined as an infusion of ≥10 units of PRBC within a 24-hour period, or ≥50% of the total blood volume replaced in less than 3 hours.
When MTP is to be activated?
It usually depends on the hospital protocol. However, several clinical scores may help this decision. The two most famous scores are:
- Shock index (SI): it is the result of heart rate/SBP. If SI >0.9, MTP should be activated;
- Trauma ABC score: it includes four parameters (i.e. penetrating truncal trauma, SBP ≤90 mmHg, HR ≥120, positive FAST). If 2 of these criteria are present, MTP should be activated.
The MTP does not include just PRBC, but all blood products (i.e. plasma and platelets). Several studies evaluated which is the best ratio to be transfused. The best results in terms of mortality were given by the 1:1:1 ratio. That means giving 6 units of PRBC, 6 units of FFP, and 1 mega-unit of platelets (≈6 units). After each cycle of MTP, blood tests should be done to monitor the patient’s status.
Blood products, as well as fluids, must be administered at 37-40°C, to avoid iatrogenic hypothermia.
According to recent studies, the best way to resuscitate a patient is by transfusing whole blood instead of separate blood components. However, for now, the use of whole blood is reserved for military settings.
|PRBC + FFP + Plt + Cryo||Whole Blood|
|680 mL |
Coagulation factors 65%
Fibrinogen 1 g
|500 mL |
Coagulation factors 100%
Fibrinogen 1 g
There are two ways to fight the so-called “acute coagulopathy of trauma shock”: the good old way, and the brand new one:
- The first one consists of addressing coagulopathy as a single entity following a single pathway. Basically, the principle is to give patients all you’ve got;
- The second one is based on a targeted approach. Ask for specific coagulation tests (e.g. TEG, ROTEM, …) and correct what’s deranged.
Let’s focus on the newer and more elegant way to address this problem.
We have already stated that FFP should be used along with all the other blood products with the MTP. This should be the first approach to a traumatized patient. In the meanwhile, blood should be drawn to run coagulation tests (along with all the other important lab tests we need). The TEG is able not only to give us information about the patient’s coagulation status, but to determine which part of the coagulation pathway is impaired (e.g. coagulation factors, fibrinogen, platelets, or excess fibrinolysis).
In this setting, there are two other products we might use if needed:
- Fibrinogen or cryoprecipitate: cryoprecipitate is a mixture of fibrinogen, von Willebrand factor, and factor VIII, and one unit contains about 200-250 mg of fibrinogen. The goal is to keep fibrinogen >1 g/L. Therefore, if it is below this cut-off, fibrinogen 1 g or cryoprecipitate 2 pools should be administered at a time, until the derangement is corrected.
- Antifibrinolytic drugs: tranexamic acid 1 g IV over 10 min followed by 1 g in 250 mL NS infused over 8 h. This treatment should be started within 3 hours of injury to improve survival. Some authors recommend using antifibrinolytic drugs with caution because of the higher risk of thromboembolic events. However, there is no uniformity in the literature on this matter.
Additional units of FFP and platelets should be given if INR >1.5 and Plt count <75’000/μL, respectively.
We hope everything was clear enough…
Remember that if you have any doubt, question, or criticism, feel free to leave it in the comment section below.
See you next time…
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- Cannon JW, et al. Damage control resuscitation in patients with severe traumatic hemorrhage: a practice management guideline from the Eastern Association for the Surgery of Trauma. J Trauma Acute Care Surg 2017;82:605-17.
- Nickson C. Damage Control Resuscitation. Life in the Fast Lane. Published on March 31, 2019. Accessed on August 6, 2020. Available at [https://litfl.com/damage-control-resuscitation/].
- Weingart S. EMCrit Podcast 30 – Hemorrhagic Shock Resuscitation. EMCrit Blog. Published on August 15, 2010. Accessed on August 6, 2020. Available at [https://emcrit.org/emcrit/trauma-resuscitation-dutton/].
- Wise R, et al. Strategies for intravenous fluid resuscitation in trauma patients. World J Surg 2017;41:1170-83.
- Braasch MC, et al. The evolution of initial-hemostatic resuscitation and the void of posthemostatic resuscitation. J Trauma Acute Care Surg 2020;89:597-601.
- Cap AP, et al. Whole blood transfusion. Military Medicine 2018;183:45-51.
- Kraut JA, et al. Lactic acidosis. NEJM 2014;371:2309-19.
How to Cite This Post
Bellio G, Marrano E. The Art of Alchemy – Part 2. Surgical Pizza. Published on November 7, 2020. Accessed on July 31, 2021. Available at [https://surgicalpizza.org/critical-care/the-art-of-alchemy-part-2/].