Trauma

Shock

A state in which cells become dysfunctional due to insufficient oxygen supply or the inability to utilize oxygen effectively.

Three Primary Stages of Shock

A. Initial/Compensatory Stage (EARLY PHASE)

  • The sympathetic nervous system (SNS) and renin-angiotensin-aldosterone system (RAAS) become activated to maintain perfusion.
  • Reduced cardiac output (CO) or low oxygen levels trigger vasoconstriction.
  • The body compensates to maintain blood pressure (BP).
  • Signs & Symptoms: No significant change in BP, restlessness, rapid heart rate, increased respiratory rate.

B. Progressive Stage (ONSET OF HYPOTENSION)

  • Compensatory mechanisms begin to fail, leading to a drop in BP.
  • Signs & Symptoms: Worsening tachycardia, metabolic acidosis, declining PaO2, altered mental status (AMS), and skin becoming cold, clammy, or mottled.

C. Refractory Stage (ADVANCED/FINAL PHASE)

  • The body no longer responds to treatment interventions.
  • Even if shock is reversed, death may occur due to multiple organ dysfunction syndrome (MODS).
  • Severe systemic hypoperfusion leads to:
    • Neurological effects – encephalopathy, stroke
    • Cardiac failure – ischemia, heart dysfunction
    • Pulmonary complications – acute respiratory distress syndrome (ARDS)
    • Liver failure
    • Renal failure – acute tubular necrosis (ATN)
    • Hematologic disorders – disseminated intravascular coagulation (DIC)

Types of Shock

Cardiogenic Shock

  • Most severe form of heart failure (HF).
  • The heart is unable to pump effectively, leading to low cardiac output.
  • Narrow pulse pressure is a key indicator.
  • Treatment Focus:
    • Increase heart function while reducing its workload.
    • Use positive inotropes to enhance contractility.
    • Reduce preload and afterload with vasodilators, intra-aortic balloon pump (IABP), or ventricular assist devices (VAD).
    • Supplemental oxygen or mechanical ventilation as needed.

Hypovolemic Shock

  • Occurs due to a severe reduction in circulating blood volume.
  • Can be classified as hemorrhagic (blood loss) or non-hemorrhagic (fluid loss).
  • Causes:
    • Internal: Fluid shift into tissues (third-spacing).
    • External: Gastrointestinal losses, renal fluid loss, burns, or hemorrhage.
  • Signs & Symptoms: Low blood pressure (↓BP), narrow pulse pressure (<40 mmHg).
  • Treatment Focus:
    • Identify and address the cause.
    • Immediate volume replacement (blood products or isotonic fluids like 0.9% NS/LR).
    • Avoid vasopressors initially as they increase systemic vascular resistance (SVR), worsening hypoperfusion.
    • Maintain key perfusion targets:
      • Mean arterial pressure (MAP) > 65 mmHg
      • Central venous pressure (CVP) between 6-10 mmHg
      • Urine output > 0.5 mL/kg/hr

Sepsis & Septic Shock

  • Focus on preventing multiple organ failure (MODS).
  • Leading cause of death in non-cardiac intensive care units (ICUs).
  • Affects multiple body systems, requiring comprehensive management.

Systemic Inflammatory Response Syndrome (SIRS)

  • Diagnosed when two or more of the following criteria are met:
    • Body temperature <36°C or >38°C
    • Heart rate exceeding 90 beats per minute
    • Respiratory rate over 20 breaths per minute
    • White blood cell count outside the normal range (<4,000 or >12,000)

Sepsis

  • SIRS criteria met along with a suspected infection.
  • No indication of organ dysfunction.

Severe Sepsis

  • Sepsis accompanied by signs of organ impairment, including:
    • Altered level of consciousness (LOC)
    • Decreased blood pressure (BP)
    • Low oxygen levels (hypoxemia)
    • Lactate levels above 2 mmol/L
    • Reduced urine output (UOP)

Septic Shock

  • Severe sepsis that persists despite fluid resuscitation, characterized by:
    • Mean arterial pressure (MAP) below 65 mmHg despite adequate fluid administration OR requiring vasopressors.

Treatment Goals:

  • Achieve and maintain MAP > 65 mmHg
  • Restore normal mental status and heart rate
  • Control the infection
  • Administer fluids (30mL/kg crystalloid solution) for resuscitation
  • Use vasopressors if blood pressure remains low:
    • First choice: Norepinephrine (LEVO)
    • Second choice: Vasopressin (VASO)
  • Start broad-spectrum antibiotics immediately after obtaining blood cultures
  • Increased central venous oxygen saturation (SVO₂) in septic shock occurs because cells fail to properly utilize oxygen from the bloodstream.
  • Elevated cardiac output (CO) and cardiac index (CI) in septic shock result from a compensatory increase in heart rate.
  • Reduced systemic vascular resistance (SVR) in septic shock is caused by widespread blood vessel dilation.
  • Higher systemic vascular resistance (SVR) in hypovolemic shock occurs due to blood vessel constriction compensating for fluid loss.

Trauma Response

  • Can be a critical or fatal event, requiring rapid assessment and intervention.
  • Evaluation follows a two-stage process:

Primary Assessment (ABCDE Approach)

  1. Airway – Ensure a clear airway using oral or nasal adjuncts if necessary.
  2. Breathing – Provide 100% oxygen and assist ventilation as needed.
  3. Circulation – Establish two large-bore IV lines and initiate fluid resuscitation.
  4. Disability – Assess level of consciousness (LOC), motor/sensory function (CMS), and Glasgow Coma Scale (GCS).
  5. Exposure – Ensure patient safety and monitor body temperature.

Secondary Assessment (FGHI Approach)

  1. Full set of vital signs – Continuously monitor the patient.
  2. Provide comfort measures – Address pain and distress.
  3. History collection – Identify medications, allergies, and relevant medical conditions.
  4. Thorough inspection – Examine the entire body, ensuring no injuries are overlooked.

Toxic Ingestion & Overdose Management

  • If the patient is unresponsive, initiate treatment that addresses potential underlying causes.
    • Naloxone (2mg) → Suspected opioid overdose
    • Dextrose 50% → Possible hypoglycemia
    • Thiamine (50-100mg) → Alcohol-related conditions
    • Acetaminophen overdose → Administer N-acetylcysteine
    • Alcohol toxicity → Use gastric lavage, IV fluids, and thiamine
    • Benzodiazepine overdose → Administer flumazenil (Romazicon) and ensure airway protection
    • Beta-blocker overdose → Treat with epinephrine and sodium bicarbonate
    • Carbon monoxide poisoning → Provide 100% oxygen therapy
    • Cocaine toxicity → Use benzodiazepines and vasodilators
    • Cyclic antidepressant overdose → Treat with activated charcoal
    • Ethylene glycol poisoning → Administer ethanol or initiate hemodialysis
    • Opioid toxicity → Naloxone administration and airway support
    • Aspirin overdose → Use activated charcoal or hemodialysis if necessary

Sedation & Pain Management

  • Analgesics are administered before sedatives or anxiolytics.
  • First-choice IV pain medications: Hydromorphone (Dilaudid), Morphine, and Fentanyl
  • Monitor for side effects: Decreased respiratory rate and hypotension
  • Sedation options: Lorazepam (Ativan), Midazolam (Versed), Propofol, and Dexmedetomidine (Precedex)
  • Maintain a light level of sedation (RASS score 0 to -2)
  • For continuous infusions, conduct a daily sedation break.
  • If the patient does not tolerate sedation reduction:
    • Increased agitation, rapid breathing, difficulty breathing, oxygen levels <90%, or hypotension

Targeted Temperature Management (TTM)

  • Lowers brain metabolic activity and oxygen consumption.
  • Inclusion criteria:
    • Cardiac arrest witnessed, with downtime under 60 minutes
    • Return of spontaneous circulation (ROSC)
    • Unresponsive and not following commands (GCS <8)

Three Phases of TTM:

➢ Cooling Phase

  • Start cooling immediately
  • American Heart Association (AHA) recommends target temperature of 32-36°C
  • Consider: Elevated glucose, low potassium, and shifts in electrolytes/fluids

➢ Maintenance Phase

  • Maintain target cooling temperature for 24 hours
  • Consider: Insulin infusion, sedation, or paralytics for shivering control
  • Shivering increases oxygen consumption
  • Monitor using Train-of-Four (TOF), aiming for 1-2 twitches

➢ Rewarming Phase

  • Slowly increase body temperature at 0.5-1°C per hour
  • Stop potassium infusions at least 8 hours before rewarming to prevent rebound hyperkalemia
  • Discontinue sedation and paralytics
  • Perform frequent neurological assessments

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