circulation

Introduction to Trauma - Circulation

Lesson Objectives

  • By the end of this lesson, students will be able to:
    • Describe hemorrhagic shock pathophysiology.
    • Recognize the clinical signs of hemorrhagic shock.
    • Explain basic shock management.
    • Describe special considerations in shock management, including age, athletes, hypothermia, medications, pacemakers, and pregnancy.

Dispatch Information

  • Incident details:
    • Patient: 40-year-old male.
    • Scenario: Involvement in a motorcycle accident on Al Ain Road.
    • Incident Description: Motorcycle lost control and was subsequently struck by a passing car.
    • Current Condition: Patient is lying on the ground with blood visible around him.
    • Time of Report: 07:38 AM, 9/9/2025.

Scene Size-Up and General Impression

  • Scene Size-Up Considerations:

    • Police have stopped traffic.
    • Use of Personal Protective Equipment (PPE)?
    • Motorcycle presence: lying on the side of the road with one patient.

  • General Impression of the Patient:

    • Position: Patient lying in a pool of blood next to the motorcycle.
    • Bleeding: Noted from the right foot.
    • Condition of Motorcycle: Not deformed.
    • Safety Gear: The rider has an open-face helmet.
    • Considerations for C-spine injury.

Primary Survey

  • Immediate findings:
    • Expose and note: Profuse bleeding from the right foot (management needed).
    • Airway: Tenuous with sonorous respirations; helmet in place (management needed).
    • Breathing: Fast, shallow, equal chest rise (management needed).
    • Circulation: Rapid, thready radial pulse, cool clammy skin (assessment needed).
    • Neurological Status: Unconscious, withdraws from painful stimulus.
    • Additional Findings: Abrasion and bruising observed in the left upper quadrant (LUQ).

Discussion Points from Primary Survey

  • Discussion Questions:
    • Why do we check for bleeding first?
    • What is your priority if you find external hemorrhage?
    • Can pressure be released once the bleeding has stopped?
    • What if direct pressure does not work?
    • How does a tourniquet operate?
    • What steps should be taken if there are no visible signs of external hemorrhage?

Case Progression

  • Continuing management:
    • Control of hemorrhage achieved with direct pressure.
    • Helmet removed, followed by a trauma chin-lift and insertion of a NPA (nasopharyngeal airway).
    • Respiratory Rate (RR): 24 breaths/min, shallow, Bilateral Breath Sounds (BBS) = Clear to Auscultation (CTA), SPO2 93%/Room Air (RA).
    • Heart Rate (HR): 126 beats/min, thready radial pulse, cool clammy skin, Blood Pressure (BP): 98/74 mmHg (management needed).
    • Patient: Regaining consciousness and following commands to move extremities.
    • Action Taken: Patient covered to maintain normothermia.

Ongoing Discussion in Case Progression

  • Is the patient in shock?
  • What signs of shock are evident?
  • Definition of shock and its time sensitivity?
  • Critical decision-making regarding transport.

Reassessment

  • Management reassessment:
    • Hemorrhage control maintained with hemostatic pressure dressing.
    • Patient interaction: Now answering questions.
    • RR: 20, good chest rise, BBS = CTA, SPO2 97%/Nasal Cannula (NC).
    • HR: 112, thready radial pulse, strong carotid, cool clammy skin, BP: 96/72 mmHg.
    • Glasgow Coma Scale (GCS): 15 (Eye: 4, Verbal: 5, Motor: 6), all extremities moving.
    • Further observations: Abrasion and bruising noted in LUQ.

Discussing Importance of Reassessment

  • Importance in checking airway and breathing.
  • Potential for internal bleeding?
  • Concept of damage control resuscitation in trauma contexts.

Impact of Blood Loss on the Body

  • Discuss the body's physiological response to blood loss:
    • Loss of blood leads to systemic effects:
    • Can organs function without adequate oxygen?
    • Identification of organs most susceptible to damage:
    • Organs sustaining damage first: Heart, brain, lungs within 4-6 minutes.
    • Kidneys, liver, gastrointestinal tract with a time of 45-90 minutes.
    • Longer tolerance for muscle, bone, skin: 4-6 hours.

Classes of Hemorrhage

  • Understanding difficulties in estimating blood loss:
    • Distinction between external and internal blood loss.
    • Average adult blood volume: 5 liters (approximately 65 ml/kg).
    • Clinical signs adapt based on progression of shock:
Class I Hemorrhage
  • Mentation: Slightly anxious.
  • Ventilatory rate: 14–20 breaths/min.
  • Pulse: < 100 beats/min.
  • Blood Pressure: Normal systolic/diastolic.
  • Skin Condition: Warm, dry.
Class II Hemorrhage
  • Mentation: Mildly anxious.
  • Ventilatory rate: 20–30 breaths/min.
  • Pulse: 100–120 beats/min.
  • Blood Pressure: Normal systolic.
  • Pulse Pressure: Decreased.
  • Skin Condition: Cool.
Class III Hemorrhage
  • Mentation: Anxious, confused.
  • Ventilatory rate: 30–40 breaths/min.
  • Pulse: 120–140 beats/min.
  • Blood Pressure: Decreased.
  • Pulse Pressure: Decreased.
  • Skin Condition: Cool, diaphoretic, pale.
  • Urine Output: 5–15 ml/hr.
Class IV Hemorrhage
  • Mentation: Difficult to arouse.
  • Ventilatory rate: > 35 breaths/min.
  • Pulse: > 140 beats/min.
  • Blood Pressure: Decreased.
  • Pulse Pressure: Decreased.
  • Skin Condition: Cool, diaphoretic, pale.
  • Urine Output: < 5 ml/hr.

Special Considerations in Shock Management

  • Variables affecting shock management:
    • Athletes.
    • Geriatric patients.
    • Medications influencing response.
    • Patients with pacemaker implants.
    • Pediatric patients.
    • Pregnant patients.

Discussion on Transport Decisions and Shock Treatment

  • How to manage internal bleeding?
  • Meaning of rapid transport in emergency cases?
  • Should intravenous (IV) access be prioritized over timely transport?
  • Components of basic shock treatment strategies.

Types of Shock

  • Overview of shock types significant in trauma management:

    • Cardiogenic Shock.
    • Distributive Shock.
    • Hypovolemic Shock.
    • Neurogenic Shock.
    • Obstructive Shock.

  • Assumption: In trauma patients, assume shock is due to hemorrhage until proven otherwise.

Hypothermia in Trauma Patients

  • Importance of body temperature regulation:
    • Effects of hypothermia on trauma patients.
    • Impact of hypothermia on mortality rates during trauma.
    • Preventative measures for hypothermia in field situations.

Case Summary

  • Summary of patient management:
    • Secondary survey completed during transport.
    • Transported to a Level I trauma center.
    • Diagnosis on arrival: ruptured spleen with internal bleeding.
    • Surgical procedure: splenectomy performed successfully.
    • Recovery: Good postoperative outcome after 5 days in the hospital.

Discussion Prompt

  • What is the Trauma Diamond?

Understanding Acidemia

  • Pathophysiology explained:
    • End organ dysfunction linked to transfusion of acidic blood products leads to:
    • Enzymatic dysfunction of clotting factors and intracellular mechanisms in the citric acid cycle.
    • This results in further coagulopathy and dysregulation in citrate metabolism:
      • Increased circulating citrate levels hinder ionized calcium homeostasis, leading to:
      • Hypocalcemia, affecting coagulation, cardiac signaling (risk of arrhythmias), and smooth muscle contraction (risk of hypotension).
Coagulopathy Factors
  • Citrate's effects:
    • Thrombin generation increasing clot formation times.
    • Contributing to storage lesions in platelet concentrates, affecting platelet function and promoting anaerobic metabolism.
Effects of Hypothermia on Citrate Metabolism
  • Significant findings:
    • 65% higher peak citrate levels compared to normothermic doses.
    • 42% slower metabolism at equivalent citrate concentrations at normothermia.

Critical Actions in Emergency Treatment

  • Prioritizing interventions:
    • Control life-threatening hemorrhage first with direct pressure.
    • Maintain a patent airway.
    • Support ventilation and oxygenation as necessary.
    • Conduct circulation assessment to identify signs of shock and further sources of bleeding.
    • Reassess perfusion following initial management.

Summary of Key Takeaways

  • Spine the focus toward:
    • Stopping the bleeding immediately.
    • Using the primary survey to identify life-threatening conditions.
    • Optimizing patient oxygenation during management.
    • Ensuring normothermia to improve outcomes.
    • Acknowledge that internal bleeding cannot be stopped in the field; prioritize rapid transport to medical facilities.
    • Pay careful attention to the Trauma Diamond to avoid complications during trauma care.

References

  • American College of Surgeons Committee on Trauma (2020). Prehospital Trauma Life Support, Ninth Edition. Jones & Bartlett Learning.
  • Andrew Pollak (2018). Nancy Caroline’s Emergency Care in the Streets, Eighth Edition. Jones & Bartlett Learning.