Circulation assessment and hemorrhage control

Circulation Assessment - What's the Pressure?

• Initial Check: Palpable pulses offer a rapid SBP estimate.
  • Carotid pulse ≈ SBP 60 mmHg
  • Femoral pulse ≈ SBP 70 mmHg
  • Radial pulse ≈ SBP 80 mmHg
  • 📌 Mnemonic: C-F-R → 60-70-80
• Key Indicators of Shock:
  • Early: Tachycardia, cool/clammy skin, narrowed pulse pressure ($SBP - DBP$).
  • Late: Hypotension, altered mental status, oliguria (<0.5 mL/kg/hr).
  • Capillary refill >2 seconds.

⭐ Base deficit < -6 mEq/L or lactate > 2.5 mmol/L are sensitive markers for occult hypoperfusion and guide resuscitation.

• Assessment Flow:

Hemorrhage Control - Plugging the Leaks

• Stop the Bleed: The immediate priority is controlling external hemorrhage. The best initial step is direct manual pressure.
• Tourniquets: For life-threatening extremity bleeding unresponsive to direct pressure. Apply ~2-3 inches proximal to the wound, tighten until bleeding stops, and record the time of application.
• Hemostatic Agents: Use as an adjunct for junctional or torso wounds. Pack the wound directly with hemostatic gauze (e.g., kaolin, chitosan) and hold firm pressure.
• Pelvic Binder: Suspect pelvic fracture in any high-energy blunt trauma. A binder stabilizes the pelvis, reduces pelvic volume, and helps tamponade venous bleeding.

⭐ Administer Tranexamic Acid (TXA) if significant hemorrhage is suspected. Give 1g IV over 10 mins within 3 hours of injury, followed by a 1g infusion over 8 hours.

Fluid Resuscitation - The Juice Boost

• IV Access: Goal is 2 large-bore peripheral IVs (≥16-gauge). If peripheral access fails, intraosseous (IO) is the next-best step for rapid infusion. Central lines are slower.
• Initial Fluid Challenge: Rapidly infuse 1L of warmed isotonic crystalloid. Lactated Ringer's is preferred over Normal Saline to avoid hyperchloremic metabolic acidosis.
  • Pediatric dose: 20 mL/kg.
• Monitor Response: Continuously assess vitals, urine output (goal >0.5 mL/kg/hr), and mental status to classify response.

⭐ Massive Transfusion Protocol (MTP): Activated for severe, ongoing hemorrhage. A balanced resuscitation with a 1:1:1 ratio of pRBCs:FFP:Platelets is crucial to combat the lethal triad of trauma (hypothermia, acidosis, coagulopathy).

Massive Transfusion - Code Red Protocol

• Activation: Triggered by severe, uncontrolled hemorrhage (e.g., >4 units pRBC in 1 hr) to pre-empt the lethal triad of trauma (acidosis, hypothermia, coagulopathy).
• Ratio: 1:1:1 (Packed Red Blood Cells : Fresh Frozen Plasma : Platelets).
• Adjuncts:
  • Tranexamic Acid (TXA): 1g IV over 10 min, then 1g over 8 hrs.
  • Calcium: Replace empirically to counteract citrate toxicity.

⭐ The primary goal of the 1:1:1 ratio is to mimic whole blood, thereby treating coagulopathy aggressively and early.

High‑Yield Points - ⚡ Biggest Takeaways

• Tachycardia is the earliest sign of shock; hypotension is a late, ominous finding.
• Control external bleeding with direct pressure, followed by tourniquets for life-threatening extremity hemorrhage.
• Initial fluid resuscitation is 1-2L of warmed crystalloids (Lactated Ringer's preferred).
• A drop in systolic blood pressure typically signifies Class III hemorrhage (30-40% blood loss).
• For massive transfusion, use a 1:1:1 ratio of PRBCs, FFP, and platelets.
• Adequate resuscitation is monitored by normalizing vitals and a urine output of >0.5 mL/kg/hr.