Trauma Resuscitation: Golden Hour, fluid management

Introduction
Trauma resuscitation represents a cornerstone of emergency and critical care, where rapid, systematic intervention within the so-called “Golden Hour” can substantially reduce morbidity and mortality. This “Golden Hour” concept refers to the early period following traumatic injury—traditionally the first 60 minutes—when prompt diagnosis and treatment of life-threatening injuries most significantly influence outcomes. Fluid management is a critical element in stabilizing hemorrhagic shock and other trauma-related hypoperfusion states. This lesson delves into the Golden Hour approach, outlines trauma resuscitation priorities, and highlights fluid therapy strategies consistent with advanced veterinary emergency and critical care principles for Membership in the Australian and New Zealand College of Veterinary Scientists (MANZCVS).

1. Overview of the Golden Hour in Trauma

1.1. Rationale and Historical Context

• Definition

  • The first hour post-injury is believed to be pivotal for identifying and addressing life-threatening issues (e.g., hemorrhage, airway compromise, severe head trauma).

• Application in Veterinary Settings

  • Adapts from human trauma concepts, focusing on immediate triage, rapid transport, and early interventions to reduce shock and fatal complications.

1.2. Key Priorities in the Golden Hour

1. Primary Survey (ABCs)

   • Airway with cervical spine protection, Breathing, Circulation.

   • Immediate life threats (airway obstruction, tension pneumothorax, massive hemorrhage) must be swiftly corrected.

2. Rapid Diagnostic Assessment

   • Quick physical exam, point-of-care ultrasound (FAST scan), and basic labs (PCV/TS, lactate) to gauge severity.

3. Initial Fluid Resuscitation and Hemorrhage Control

   • IV access, consider balanced crystalloids or blood products if indicated.

4. Continuing Reassessment

   • Re-evaluate vital signs and response to therapy, cycle rapidly through ABCs as the patient stabilizes or deteriorates.

2. Trauma Resuscitation Framework

2.1. Triage and Stabilization

1. Primary Survey

   • Airway: Ensure patency; administer oxygen or secure endotracheal tube if compromised.

   • Breathing: Evaluate chest motion, auscultation; treat pneumothorax or open chest wounds.

   • Circulation: Palpate pulses, check mucous membranes, manage external hemorrhage (direct pressure, bandages).

2. Secondary Survey

   • Detailed head-to-tail exam once the patient is more stable.

   • Identification of fractures, internal injuries, or concurrent conditions.

2.2. Rapid Diagnostic Tools

• Focused Assessment with Sonography for Trauma (FAST)

  • Quick detection of free fluid (hemoperitoneum, pericardial effusion).

• Point-of-Care Laboratory

  • PCV/TS, lactate, blood glucose.

• Baseline Imaging

  • Radiographs of chest/abdomen, orthopedic films once stable.

3. Fluid Management in Trauma Resuscitation

3.1. Goals of Fluid Therapy

1. Restore and Maintain Tissue Perfusion

   • Support intravascular volume to correct hypovolemia from hemorrhage or fluid sequestration.

2. Optimize Oxygen Delivery

   • Ensure adequate preload for cardiac output while avoiding fluid overload.

3. Limit Exacerbation of Hemorrhage

   • Overly aggressive crystalloid administration can dislodge clots or dilute coagulation factors.

3.2. Fluid Selection and Resuscitation Strategies

1. Crystalloids

   • Isotonic Balanced Solutions (e.g., Lactated Ringer’s, Plasmalyte) are frequently used first-line.

   • 0.9% NaCl for specific indications (e.g., hyperkalemia, head injury), but watch for acid–base derangements.

   • Bolus increments (10–20 mL/kg in dogs, 5–10 mL/kg in cats) repeated as needed, assessing perfusion response.

2. Colloids

   • Synthetic Colloids (e.g., hydroxyethyl starch) can expand intravascular volume with smaller volumes.

   • Potential adverse effects (coagulopathy, fluid overload) require cautious use, especially if hemorrhagic shock.

   • Albumin or plasma may benefit if significant protein loss or coagulopathy.

3. Blood Products

   • Packed Red Blood Cells (pRBCs) for significant anemia or hemorrhage.

   • Fresh Frozen Plasma if coagulopathy is present.

   • Whole Blood for major hemorrhage with hypoproteinemia or clotting factor deficits.

4. Hypotensive Resuscitation Concept

   • In penetrating trauma with uncontrolled hemorrhage, mild hypotension (systolic ~90 mmHg) may be acceptable until surgical control of bleeding.

   • Minimizes risk of dislodging early clots, though less common in veterinary blunt trauma scenarios.

3.3. Monitoring and Adjusting Therapy

1. Perfusion Parameters

   • Heart rate, blood pressure (direct/indirect), capillary refill time, lactate.

2. Urine Output

   • Foley catheter if indicated; aim ≥0.5–1 mL/kg/hr in dogs/cats.

3. PCV/TS

   • Re-check if ongoing hemorrhage suspected; guide transfusion decisions.

4. Respiratory Status

   • Overzealous fluids can cause volume overload or exacerbate pulmonary contusions.

4. Complications and Considerations

4.1. Hemorrhagic Shock

• Persistent Bleeding

  • Identify source: Splenic rupture, hepatic laceration, major vessel tear.

  • Surgical intervention or auto-transfusion if feasible.

• Goal-Directed Resuscitation

  • Incorporate vasopressors only after volume optimization if hypotension persists.

4.2. Coagulopathies

• Dilutional and Consumptive

  • Large-volume crystalloid can dilute clotting factors, platelets.

  • Evaluate for DIC if multi-organ trauma, sepsis.

• Blood Product Support

  • FFP or platelet-rich plasma for coagulopathy.

4.3. Hypothermia, Acidosis, Hypocalcemia

• Trauma Triad of Death

  • Hypothermia can worsen coagulopathy, hamper perfusion.

  • Address underlying acidosis with appropriate fluid therapy, ventilation if needed.

  • Monitor ionized calcium if massive transfusions used.

Conclusion

In trauma resuscitation, the “Golden Hour” underscores the urgency of timely intervention to stabilize hemorrhage, airway compromise, and other life-threatening injuries. Fluid management plays a critical role, balancing volume replacement against the risk of exacerbating bleeding or causing fluid overload. An incremental, goal-directed approach with isotonic crystalloids and, where indicated, colloids or blood products is fundamental. Ongoing reassessment of perfusion, vital signs, and laboratory parameters ensures that therapy is rapidly adjusted to evolving patient needs. By employing these strategies, veterinary professionals deliver evidence-based care aligned with the advanced competencies of MANZCVS Veterinary Emergency and Critical Care, thereby optimizing trauma survival and recovery.

Suggested References

1. Silverstein, D. C., & Hopper, K. (Eds.). (2014). Small Animal Critical Care Medicine (2nd ed.). Saunders.

2. Dunn, M. E., & Boller, M. (2017). The principles of triage and early stabilization. Journal of Veterinary Emergency and Critical Care, 27(S1), S6–S22.

3. Prittie, J. (2013). Fluid therapy in small animal practice. Veterinary Clinics of North America: Small Animal Practice, 43(5), 1039–1054.

4. Holowaychuk, M. K. (2015). Management of severe hemorrhage in the emergency setting. In Kirk’s Current Veterinary Therapy XV. Elsevier.

5. Kirby, R., & Rudloff, E. (2018). Trauma and the Golden Hour concept in veterinary medicine. Veterinary Clinics of North America: Small Animal Practice, 48(6), 1101–1123.