A 28-year-old woman is admitted with Class II hemorrhagic shock following blunt abdominal trauma from a fall. During the initial resuscitation phase, all of the following interventions are appropriate EXCEPT:

Explanation

## Hemorrhagic Shock Resuscitation: Appropriate vs. Inappropriate Interventions ### Overview of Class II Hemorrhagic Shock **Key Point:** Class II hemorrhagic shock (15–30% blood volume loss) presents with tachycardia, tachypnea, mild anxiety, and decreased urine output. It is partially compensated and requires prompt fluid resuscitation and identification of bleeding source. ### Evaluation of Each Intervention | Intervention | Appropriateness | Rationale | |--------------|-----------------|----------| | 2 L crystalloid bolus (warmed) | ✓ **Appropriate** | ATLS protocol recommends initial 1–2 L crystalloid bolus for Class II–III shock. Warmed fluids prevent hypothermia-induced coagulopathy. | | Type O-negative blood for massive hemorrhage | ✓ **Appropriate** | O-negative (universal donor) blood is indicated when massive hemorrhage is anticipated before type-matched blood is available. Prevents delay in transfusion. | | Aggressive hyperventilation (PaCO₂ 25–30 mmHg) | ✗ **INAPPROPRIATE** | Hyperventilation causes respiratory alkalosis, which impairs oxygen delivery to tissues, worsens cerebral vasoconstriction, and increases risk of arrhythmias. Contraindicated in hemorrhagic shock. | | Large-bore IV access (16–18 G) and IO access | ✓ **Appropriate** | Large-bore peripheral lines maximize flow rate. Intraosseous access is a valid alternative when peripheral access fails, especially in children or during cardiac arrest. | ### Clinical Pearl **Hyperventilation in Trauma:** - ~~Hyperventilation improves oxygenation in hemorrhagic shock~~ — **FALSE** - Hyperventilation causes **respiratory alkalosis**, which: - Shifts the oxygen–hemoglobin dissociation curve **left** (reduces oxygen release to tissues) - Causes cerebral vasoconstriction (worsens perfusion) - Increases risk of cardiac arrhythmias - **Appropriate ventilation:** Maintain normal PaCO₂ (35–45 mmHg) with adequate oxygenation (SpO₂ >94%) ### High-Yield Concept **Mnemonic — ATLS Resuscitation Priorities in Hemorrhagic Shock:** - **A**irway with cervical spine protection - **B**reathing with normal ventilation (not hyperventilation) - **C**irculation with large-bore IV access, warmed fluids, and early blood transfusion - **D**isability assessment - **E**xposure and environment (prevent hypothermia) ### Warning **Common Exam Trap:** Hyperventilation is sometimes confused with beneficial oxygenation. Remember: in hemorrhagic shock, the problem is **tissue perfusion**, not oxygenation alone. Hyperventilation worsens perfusion by causing alkalosis and vasoconstriction. [cite:ATLS 10th Edition, American College of Surgeons; Harrison 21e Ch 297]