13.2 Trauma Pharmacotherapy: Massive Transfusion, TXA, Open Fractures, Tetanus & Burns
Key Takeaways
Damage Control Resuscitation (DCR) prioritizes permissive hypotension (target SBP 80-90 mmHg, MAP 50-65 mmHg in non-TBI patients), restricts crystalloids, and delivers balanced 1:1:1 blood component therapy (PRBCs, FFP, and platelets), which the landmark PROPPR trial validated reduces 24-hour exsanguination mortality.
Tranexamic acid (TXA) must be initiated within 3 hours of traumatic injury (1 g IV over 10 min followed by 1 g IV infusion over 8 hours); starting it more than 3 hours after injury increased death due to bleeding in CRASH-2.
Open fractures need antibiotics within 1 hour (cefazolin for Gustilo types I–II, ceftriaxone for type III, plus penicillin for farm or fecal contamination), and contaminated wounds need tetanus toxoid if 5 or more years have passed, plus TIG when the vaccine history is incomplete.
Citrate in transfused blood components chelates ionized calcium, precipitating severe hypocalcemia and blunting the clotting cascade; proactive empiric calcium repletion (1 g calcium chloride or 3 g calcium gluconate per 4 units of blood products) is mandatory.
Acute thermal burn fluid requirements are calculated using modified Brooke/Parkland formulas (2-4 mL x kg x % TBSA Lactated Ringer's), delivering 50% within the first 8 hours post-injury and titrating strictly to an adult urine output of 0.5 mL/kg/h to avoid fatal fluid creep.
13.2 Trauma Resuscitation, Hemorrhage Control & Acute Burn Management
Note
Independent BCEMP study resource provided by OpenExamPrep. Content is organized around emergency medicine pharmacotherapy principles tested on clinical specialist certification examinations.
Damage Control Resuscitation (DCR) & The Lethal Diamond
Severe traumatic injury induces a rapid, life-threatening derangement historically termed the Lethal Triad: Hypothermia (<35°C, which suppresses coagulation enzyme kinetics), Acidosis (pH <7.2, which drastically reduces thrombin generation), and Coagulopathy (driven by consumption, hyperfibrinolysis, and endothelial disruption). Modern emergency resuscitation expands this concept to the Lethal Diamond by recognizing Hypocalcemia as an independent, life-threatening fourth component.
Core Tenets of Damage Control Resuscitation
- Immediate Hemorrhage Control: Rapid surgical or endovascular intervention to arrest mechanical bleeding.
- Permissive Hypotension: Maintaining a subnormal blood pressure target (systolic BP 80 to 90 mmHg or mean arterial pressure 50 to 65 mmHg) until surgical hemostasis is achieved. This prevents "popping the clot"—the mechanical dislodgement of newly formed, fragile hemostatic plugs caused by hydrostatic pressure surges. Contraindication: Permissive hypotension is strictly contraindicated in patients with severe Traumatic Brain Injury (TBI), where a minimum SBP ≥100 to 110 mmHg is required to maintain cerebral perfusion pressure (CPP ≥60 mmHg).
- Minimization of Crystalloids: Restricting isotonic crystalloid infusions (0.9% normal saline or Lactated Ringer's). Large crystalloid volumes induce dilutional coagulopathy, hypothermia, endothelial glycocalyx degradation, and hyperchloremic metabolic acidosis.
- Balanced Component Therapy: Resuscitating with blood products in fixed physiological proportions that mimic reconstituted whole blood.
Massive Transfusion Activation & Whole Blood
A Massive Transfusion Protocol (MTP) is activated for life-threatening hemorrhagic shock, for example an Assessment of Blood Consumption (ABC) score of 2 or more (penetrating mechanism, SBP 90 mmHg or less, heart rate 120 bpm or more, positive FAST). Section 3.3 covers the evidence for balanced 1:1:1 ratios (PROPPR) and viscoelastic-guided replacement. In trauma practice, the pharmacist's added tasks are:
- Product sequencing: MTP coolers typically deliver 6 units of red cells, 6 units of plasma and 1 apheresis platelet pack, repeated until hemostasis.
- Low-titer group O whole blood (LTOWB): increasingly stocked by trauma centers and EMS. It delivers red cells, plasma and platelets in one unit with less additive volume.
- Anticoagulant history: identify warfarin, DOAC or antiplatelet use at arrival and start reversal in parallel with transfusion (see Section 10.1).
- Hypothermia prevention: warm every product and fluid.
Tranexamic Acid (TXA): CRASH-2 & CRASH-3 Timing Windows
Tranexamic acid (TXA) is a synthetic lysine-analogue antifibrinolytic that reversibly blocks the lysine-binding sites on plasminogen molecules, preventing its conversion to plasmin and halting the enzymatic degradation of fibrin clots.
Dosing Protocol
- Loading Dose: 1 g IV infused over 10 minutes (rapid undiluted IV push must be avoided to prevent transient drug-induced vasodilation and hypotension).
- Maintenance Infusion: 1 g IV continuous infusion administered over 8 hours.
The 3-Hour Therapeutic Imperative (CRASH-2)
The landmark CRASH-2 trial (20,211 trauma patients with significant hemorrhage) proved that TXA significantly reduces all-cause mortality (RR 0.91) and risk of death due to bleeding (RR 0.85). Subgroup analysis revealed an absolute dependency on the timing of drug administration:
- Initiated within 1 hour of injury: Greatest survival benefit; reduces risk of death from bleeding by 32% (RR 0.68, 95% CI 0.57-0.82).
- Initiated between 1 and 3 hours of injury: Significant survival benefit; reduces risk of death from bleeding by 21% (RR 0.79, 95% CI 0.64-0.97).
- Initiated >3 hours post-injury: HARMFUL AND CONTRAINDICATED. TXA started more than 3 hours after injury was associated with a statistically significant increase in death due to bleeding (RR 1.44, 95% CI 1.12–1.84). CRASH-2 found no overall increase in vascular occlusive events with TXA.
Warning
Pathophysiologically, acute trauma triggers an immediate, transient state of hyperfibrinolysis. By 3 to 6 hours post-injury, trauma-induced coagulopathy naturally transitions into fibrinolytic shutdown characterized by microvascular thrombosis, tissue ischemia, and multiorgan failure. Administering an antifibrinolytic during late fibrinolytic shutdown accelerates microvascular occlusion and worsens mortality. Never initiate TXA in trauma patients presenting >3 hours after injury.
Traumatic Brain Injury (CRASH-3)
The CRASH-3 trial evaluated TXA in patients with acute traumatic brain injury presenting within 3 hours of injury with GCS ≤12 or intracranial hemorrhage on CT. TXA reduced head injury-related mortality specifically in patients with mild-to-moderate TBI (GCS 9-15) (RR 0.78, 95% CI 0.64-0.95), while showing no benefit in catastrophic, un-survivable severe TBI (GCS 3 or unreactive pupils).
Open Fractures, Tetanus Prophylaxis & Trauma Analgesia
Open Fracture Antibiotics
Early antibiotics are the most important modifiable factor in preventing deep infection after an open fracture. Give the first dose within 1 hour of arrival. The ACS TQIP best-practice guidance is a common reference:
| Gustilo-Anderson type | Typical empiric regimen | Notes |
|---|---|---|
| Type I–II (wound under 10 cm, moderate contamination) | Cefazolin 2 g IV (3 g if 120 kg or more) every 8 hours | Clindamycin for severe beta-lactam allergy |
| Type III (extensive soft-tissue injury, heavy contamination) | Ceftriaxone 2 g IV daily (or cefazolin plus an aminoglycoside in older protocols) | Gram-negative coverage for heavy contamination |
| Farm, soil or fecal contamination | Add penicillin (or ampicillin) for clostridia | Water exposure may need fluoroquinolone or doxycycline coverage |
Continue for about 24 hours after definitive wound closure (longer, often up to 72 hours, for type III).
Tetanus Prophylaxis (CDC/ACIP)
| Wound | 3 or more prior doses | Fewer than 3 doses or unknown |
|---|---|---|
| Clean, minor | Tdap or Td if 10 years or more since the last dose | Tdap/Td vaccine; no TIG |
| All other wounds (dirty, puncture, burns, crush) | Tdap or Td if 5 years or more since the last dose | Tdap/Td vaccine plus tetanus immune globulin (TIG) 250 units IM at a separate site |
Prefer Tdap for adults who have never received it. Patients with HIV or severe immunosuppression and a contaminated wound should receive TIG regardless of their vaccination history.
Trauma Analgesia
- Hemodynamically fragile patients: small titrated doses of fentanyl (about 0.5 to 1 mcg/kg) or sub-dissociative ketamine (0.1 to 0.3 mg/kg IV) preserve blood pressure better than morphine.
- Regional anesthesia: a fascia iliaca or femoral nerve block for hip fracture, and serratus anterior or erector spinae blocks for rib fractures, reduce opioid needs and delirium in older adults. Know the local anesthetic maximum doses (Section 9.4).
- NSAIDs: avoid in active hemorrhage, acute kidney injury and early after major surgical fixation. Acetaminophen is a safe baseline.
Citrate Toxicity & Proactive Calcium Repletion
All commercial blood products are anticoagulated with citrate (sodium citrate/citric acid), which prevents in vitro coagulation by chelating extracellular ionized calcium (coagulation Factor IV).
Pathophysiology
Under normal physiological conditions, circulating citrate is rapidly metabolized into bicarbonate by hepatic and renal pathways. During massive blood transfusion, large volumes of citrate overwhelm hepatic metabolic capacity, compounded by shock-induced hepatic hypoperfusion and hypothermia. Circulating citrate rapidly chelates endogenous ionized calcium (Ca²⁺) and magnesium (Mg²⁺).
Clinical Sequelae
- Coagulopathy: Tenase and prothrombinase complex assemblies are strictly calcium-dependent. Hypocalcemia severely inhibits thrombin generation.
- Myocardial Depression: Calcium is required for myocardial excitation-contraction coupling. Severe hypocalcemia produces refractory hypotension, reduced stroke volume, and decreased left ventricular ejection fraction.
- Electrophysiological Instability: Marked prolongation of the QT interval, ST-segment lengthening, and heightened vulnerability to polymorphic ventricular arrhythmias and asystole.
Mandatory Proactive Calcium Repletion
Waiting for laboratory calcium results during an active MTP leads to severe, preventable cardiac arrest. Empiric, proactive calcium administration is mandatory:
- Administration Trigger: Administer 1 g IV Calcium Chloride OR 3 g IV Calcium Gluconate for every 4 units of blood products transfused (or after the completion of the first MTP cooler).
- Salt Selection: Calcium chloride provides three times more elemental calcium than calcium gluconate (1 g calcium chloride = 13.6 mEq [6.8 mmol] Ca²⁺; 1 g calcium gluconate = 4.65 mEq [2.3 mmol] Ca²⁺). Both salts ionize rapidly, with no hepatic step needed. Calcium chloride delivers more calcium per syringe in critical shock, but it must be administered via central venous access or a well-running, large-bore peripheral catheter due to the risk of severe tissue necrosis if extravasated.
- Resuscitation Target: Maintain ionized calcium (iCa) >1.1 to 1.2 mmol/L throughout the resuscitation.
Acute Thermal Burn Resuscitation & Fluid Titration
Thermal burn injuries involving ≥20% Total Body Surface Area (% TBSA) trigger massive systemic capillary leak, endothelial damage, and third-space fluid sequestration ("burn shock").
Burn Size Estimation: Adult Rule of Nines
Only second-degree (partial-thickness) and third-degree (full-thickness) burns are included in % TBSA calculations; first-degree erythema (superficial sunburn) is excluded:
- Head and Neck: 9% total (4.5% anterior, 4.5% posterior)
- Anterior Torso (Chest and Abdomen): 18%
- Posterior Torso (Upper and Lower Back): 18%
- Each Upper Extremity: 9% total (4.5% anterior, 4.5% posterior; both arms = 18%)
- Each Lower Extremity: 18% total (9% anterior, 9% posterior; both legs = 36%)
- Perineum / Genitalia: 1%
- (For scattered or irregular burns, the patient's palmar surface including closed fingers equals ~1% TBSA).
Fluid Calculation: Parkland & Modified Brooke Formulas
Resuscitation is performed using balanced crystalloids (Lactated Ringer's is the fluid of choice; normal saline is avoided due to the induction of severe hyperchloremic metabolic acidosis):
- Parkland Formula: 4 mL × Weight (kg) × % TBSA burned over 24 hours
- Modified Brooke / American Burn Association (ABA) Consensus: 2 mL × Weight (kg) × % TBSA burned over 24 hours (for thermal burns; 4 mL/kg/% TBSA is reserved for electrical burns with myoglobinuria).
Resuscitation Timeline & Administration Schedule
- First 8 Hours: 50% of the total calculated 24-hour volume must be infused within the first 8 hours calculated from the EXACT TIME OF INJURY, not the time of hospital arrival. Any fluid volume infused prior to arrival is subtracted from this 8-hour total.
- Remaining 16 Hours: The remaining 50% of the calculated volume is infused evenly over the subsequent 16 hours.
Dynamic Titration & Avoiding "Fluid Creep"
Formulas provide only an initial starting estimate. Administering excessive fluid volumes causes "fluid creep", predisposing the patient to pulmonary edema, extremity compartment syndromes requiring escharotomies, and fatal Abdominal Compartment Syndrome (ACS).
Important
Crystalloid infusion rates must be titrated up or down by 20% to 30% every hour based strictly on physiological endpoints:
- Adult Target Urine Output: 0.5 mL/kg/hour (approximately 30 to 50 mL/hour).
- Pediatric Target Urine Output (<30 kg): 1.0 mL/kg/hour.
- In high-voltage electrical injuries with pigmenturia (myoglobinuria), titrate fluids to a target urine output of 1.0 to 1.5 mL/kg/hour until the urine clears.
A 34-year-old male arrives at the emergency department resuscitation bay following a high-speed motor vehicle collision with extensive pelvic fractures and intra-abdominal hemorrhage. Due to prolonged vehicle extrication, the exact time of injury was 3 hours and 50 minutes prior to hospital arrival. Vital signs: BP 76/42 mmHg, HR 138 bpm, RR 26 breaths/min. The massive transfusion protocol is activated. A junior team member suggests immediately administering tranexamic acid (TXA) 1 g IV bolus. What is the most appropriate, evidence-based recommendation regarding TXA administration for this patient?
Administer TXA 1 g IV over 10 minutes followed by 1 g IV over 8 hours, as TXA provides uniform survival benefit regardless of the post-injury interval.
Administer TXA 2 g IV bolus immediately to compensate for the delayed presentation time.
Withhold tranexamic acid, because starting it more than 3 hours after injury was associated with more deaths from bleeding in CRASH-2.
Administer TXA only if viscoelastic testing confirms an alpha angle <45 degrees.
A 48-year-old female with severe blunt polytrauma is undergoing active massive transfusion. Over the past 40 minutes, she has received 8 units of packed red blood cells, 6 units of fresh frozen plasma, and 1 apheresis platelet unit. Bedside rapid thromboelastography (r-TEG) reveals: R-time 12.2 minutes (reference 4-8 min), Alpha angle 68 degrees (reference 60-74 degrees), MA 64 mm (reference 55-73 mm), and LY30 1.0% (reference 0-3%). Arterial blood gas analysis reveals: pH 7.22, base deficit -8 mEq/L, and ionized calcium 0.74 mmol/L (reference 1.15-1.33 mmol/L). Which two pharmacotherapeutic interventions are most urgently indicated?
Administer 1 g intravenous calcium chloride (or 3 g calcium gluconate) immediately, and transfuse additional fresh frozen plasma (or 4-factor PCC) guided by the prolonged R-time.
Administer tranexamic acid 1 g IV over 10 minutes and transfuse 2 pools of cryoprecipitate guided by the alpha angle.
Transfuse two apheresis units of platelets and administer 25 grams of 25% albumin to restore oncotic pressure.
Withhold calcium supplementation until serum total calcium is known, and administer recombinant activated factor VII (rFVIIa).
A 35-year-old male weighing 80 kg sustained thermal flame burns involving his entire anterior torso (18%), his entire right arm (9%), and the anterior surface of both lower extremities (9% + 9% = 18%). The burn injury occurred at 13:00, and he arrives in the emergency department at 15:00. The burn team utilizes the Parkland resuscitation formula (4 mL x kg x % TBSA of Lactated Ringer's). What is the total volume of Lactated Ringer's allocated to the first 8 hours post-injury, and at what hourly rate should it be infused between 15:00 and 21:00?
Total 24-hour volume is 28,800 mL; allocate 14,400 mL to the first 8 hours and infuse at 2,400 mL/h guided by central venous pressure.
Total 24-hour volume is 7,200 mL; allocate 3,600 mL to the first 8 hours and infuse at 450 mL/h starting from ED arrival.
Total 24-hour volume is 14,400 mL; allocate 7,200 mL to the first 8 hours post-injury, requiring an infusion rate of 1,200 mL/h over the remaining 6 hours of that window.
Total 24-hour volume is 14,400 mL; infuse uniformly at 1,800 mL/h across the first 8 hours from time of hospital arrival.
A 30-year-old farmer has an open tibial fracture with a 12 cm wound heavily contaminated with soil (Gustilo type III). His last tetanus booster was 7 years ago after a completed primary series. He has no drug allergies. Which plan is most appropriate in the ED?
Vancomycin plus gentamicin within 6 hours, and both Tdap and tetanus immune globulin
Oral cephalexin after operative washout, and tetanus immune globulin 250 units IM without vaccine
Cefazolin 2 g IV alone, and no tetanus vaccine because his last dose was within 10 years
Ceftriaxone 2 g IV plus penicillin for soil contamination, given within 1 hour, and a Tdap booster without tetanus immune globulin
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