DA

SIRS, Sepsis, Shock, MODS

Shock Overview

  • Definition: A life-threatening syndrome of decreased tissue perfusion and impaired cellular metabolism.

  • Cause: Imbalance between oxygen/nutrient supply and demand.

  • Types of Shock:

    • Cardiogenic

    • Hypovolemic

    • Distributive (Neurogenic, Anaphylactic, Septic)

    • Obstructive

Types of Shock

1. Cardiogenic Shock

  • Cause: Heart pump failure (systolic or diastolic dysfunction).

  • Common causes: MI, cardiomyopathy, blunt cardiac injury, valve disease, arrhythmias, tamponade.

  • S/S:

    • Cardiac: Tachycardia, hypotension, ↓CO/SV, ↑SVR, ↑PAWP/CVP.

    • Neuro: Anxiety, confusion.

    • Renal: Oliguria.

    • Respiratory: Tachypnea, crackles, cyanosis.

    • Skin: Cool, clammy.

  • Treatment:

    • Restore blood flow (cardiac cath, CABG, valve surgery).

    • Reduce workload (nitrates, diuretics, vasodilators, beta blockers).

    • Mechanical support: IABP, VAD.

2. Hypovolemic Shock

  • Cause: Inadequate intravascular fluid (absolute or relative loss).

  • Absolute: Hemorrhage, GI loss, fistula drainage, diuresis.

  • Relative: Third-spacing, internal bleeding.

  • S/S: Tachycardia, ↓preload/CO, anxiety, confusion, tachypnea → bradypnea (late), ↓urine output, cool clammy skin.

  • Diagnostics: ↓H/H, ↑lactate, ↑urine specific gravity.

  • Treatment: Fluid replacement (blood, crystalloids, colloids).

3. Distributive Shock

a. Neurogenic Shock

  • Cause: Spinal cord injury (T5 or above) or spinal anesthesia.

  • Patho: Massive vasodilation due to loss of SNS tone.

  • S/S: Hypotension, bradycardia, warm dry skin, temperature dysregulation.

  • Treatment: Stabilize spine, vasopressors, atropine for bradycardia, fluids (use cautiously).

b. Anaphylactic Shock

  • Cause: Severe allergic reaction (drug, food, insect, contrast, etc.).

  • Patho: Vasodilation, ↑capillary permeability → fluid leaks into interstitial space.

  • S/S: Sudden onset, dizziness, chest pain, swelling, wheezing, stridor, hypotension, impending doom.

  • Treatment: Epinephrine IM first, airway support, fluids, antihistamines, corticosteroids, bronchodilators.

c. Septic Shock

  • Cause: Dysregulated response to infection.

  • Patho: Vasodilation, maldistribution of blood flow, myocardial depression.

  • S/S:

    • Early: Warm/flushed skin, fever.

    • Late: Cool, mottled skin, AMS, tachypnea → respiratory failure, oliguria.

  • Treatment (Surviving Sepsis Bundle):

    • Lactate, cultures before antibiotics, broad-spectrum antibiotics within 1 hr.

    • 30 mL/kg crystalloid bolus.

    • Vasopressors (norepinephrine first-line).

    • Monitor ScvO2/SvO2, glucose < 180, stress ulcer prophylaxis.

4. Obstructive Shock

  • Cause: Physical obstruction of blood flow (tamponade, tension pneumo, PE, SVC syndrome, abdominal compartment syndrome).

  • S/S: Similar to cardiogenic shock with JVD, pulsus paradoxus.

  • Treatment: Relieve obstruction (needle decompression, thrombolytics, surgery).

Stages of Shock

  1. Initial: Subtle changes, cellular hypoxia begins.

  2. Compensatory: Changes occur

    • SNS activation → vasoconstriction, tachycardia, hypotension, shunting blood to vital organs.

    • RAAS → fluid retention.

    • Cool, clammy skin; GI slowdown.

  3. Progressive:

    • ↓CO, hypotension, poor perfusion.

    • Capillary leak → edema, alveolar flooding → ARDS.

    • GI ischemia, AKI, liver dysfunction, risk for DIC.

  4. Refractory:

    • Severe hypoxia, organ failure, profound hypotension, lactic acidosis.

    • Death likely.

Nursing Management of Shock

  • Airway & Oxygenation – Maintain O2 delivery.

  • Fluid Resuscitation – Crystalloids, colloids, blood products as needed.

  • Drug Therapy:

    • Vasopressors (norepinephrine, epi, phenylephrine, dopamine).

    • Inotropes if needed.

  • Nutrition: Enteral feeds within 24 hrs to reduce gut ischemia.

  • Monitoring: Vitals, hemodynamics, urine output, labs (lactate, electrolytes).

SIRS (Systemic Inflammatory Response Syndrome)

  • Definition: Exaggerated inflammatory response with widespread vasodilation and capillary leak.

  • Criteria (need 2+):

    • Temp >38°C or <36°C

    • HR >90 bpm

    • RR >20 or PaCO2 <32

    • WBC >12k or <4k or >10% bands

MODS (Multiple Organ Dysfunction Syndrome)

  • Definition: Failure of 2 or more organ systems due to uncontrolled inflammatory response.

  • Patho: Inflammatory mediators → endothelial damage → capillary leak → tissue hypoxia → organ failure.

  • Organs affected: Lungs (ARDS), kidneys (AKI), liver (failure), heart (depression), brain (AMS).

  • Nursing Care:

    • Prevent infection, strict asepsis.

    • Optimize O2 delivery.

    • Support failing organs (dialysis, ventilation, vasopressors).

    • Provide nutrition & comfort care.