Shock

Category: Medical Sources: raw/protocols/nm-sop-guidelines-treatment-2022.pdf Last updated: 2026-04-03

Overview

Shock is a state of widespread inadequate tissue perfusion — cells cannot receive sufficient oxygen and cannot remove metabolic waste products. It is a life-threatening emergency regardless of cause. The EMT-B's role: recognize shock early (compensated shock is treatable; decompensated shock is immediately life-threatening), address the cause when possible, administer oxygen, and transport rapidly.

Shock types (see shock-physiology for full mechanism and cellular-level explanation): - Hypovolemic: Blood or fluid loss (hemorrhage, dehydration, burns, vomiting/diarrhea) - Distributive: Vasodilation causing relative hypovolemia (anaphylactic, neurogenic/spinal, septic) - Cardiogenic: Pump failure (MI, dysrhythmia, tension pneumothorax) - Obstructive: Mechanical obstruction to flow (tension pneumothorax, cardiac tamponade, massive PE)

Compensated vs. decompensated shock: - Compensated: HR increases, peripheral vasoconstriction maintains BP — BP may be NORMAL while perfusion is failing - Decompensated: BP falls (hypotension); tachycardia persists or bradycardia develops (ominous); altered LOC - Children compensate longer and crash faster than adults — normal BP in a child does not rule out shock

Key Points

• Hypotension is a late finding — shock can be present with normal BP (especially in children and young adults)
• Tachycardia + diaphoresis + altered mental status = shock until proven otherwise
• Skin signs of shock: pale, cool, moist (poor perfusion) OR hot/flushed (early septic/distributive)
• Treat the cause: hemorrhage control, epinephrine for anaphylaxis, position for neurogenic shock
• IV fluid resuscitation is ALS/EMT-I scope — EMT-B focus is O2, hemorrhage control, position, and transport
• Permissive hypotension in penetrating trauma: avoid excessive fluids that dilute clotting factors; target SBP ~90 (exception: TBI — target SBP >110)

Assessment Relevance

History (history-taking): - MOI or NOI: trauma mechanism → hemorrhagic shock; anaphylaxis trigger; cardiac history (cardiogenic); recent illness/fever (septic); spinal injury (neurogenic) - Medications: beta-blockers blunt tachycardia; anticoagulants worsen hemorrhage - Fluid intake, vomiting, diarrhea (hypovolemia)

Physical exam (secondary-assessment): - Vital signs: HR (tachycardia is earliest sign), BP (may be normal in compensated shock), RR, SpO2, skin temp, GCS - Skin: pale/cool/moist (hemorrhagic/cardiogenic/hypovolemic); hot/flushed (early sepsis, neurogenic); mottled = severe - Capillary refill: >2 seconds suggests poor perfusion - Pulse quality: weak/thready distal pulses = poor cardiac output - JVD: present in cardiogenic, tension pneumothorax, tamponade; absent in hypovolemic - Mental status: anxiety/restlessness (early compensated) → confusion → unresponsiveness - ETCO2: <25 mmHg suggests inadequate perfusion - Urine output: decreased in shock (not directly measurable prehospital but history may reveal oliguria)

NM-specific shock signs (from protocol): - Altered mental status, delayed/flash capillary refill, SpO2 <94%, ETCO2 <25 mmHg, RR >20 (adults), HR tachycardia for age, weak/decreased pulses, cool/mottled or flushed/ruddy skin - Hypotension thresholds: <1 year = SBP <60; 1–10 years = (age × 2) + 70; >10 years = SBP <90

Procedures

1. Scene size-up (scene-size-up): MOI (trauma?); scene hazards; additional resources
2. Primary assessment (primary-assessment): identify life threats — hemorrhage control first in trauma
3. Hemorrhage control: direct pressure → tourniquet → wound packing — see bleeding-control-shock
4. Position: supine with legs elevated (unless respiratory distress or c-spine precautions needed); left lateral for pregnancy
5. Oxygen: high-flow O2 via NRB — see oxygen-administration
6. Warmth: prevent heat loss (blanket)
7. Priority transport — do NOT delay on scene for IV access
8. Request ALS intercept for IV fluid resuscitation

IV fluids (NM EMT-B scope — initiate IV if trained; this may be limited in some systems): - Primary role of EMT-B: obtain IV access; fluids administered based on protocol - 20 mL/kg isotonic fluid bolus (up to 1 liter max) over <15 minutes - Repeat up to 3 times; reassess after each bolus

NM Protocol Notes

From NM EMS Treatment Guidelines (2022):

Shock assessment criteria: Signs of poor perfusion requiring action: - AMS, delayed/flash capillary refill, SpO2 <94%, ETCO2 <25 mmHg, decreased urine output, RR >20 (adults), age-appropriate hypotension, tachycardia for age, weak/decreased/bounding pulses, cool/mottled or flushed/ruddy skin

Hypotension thresholds: - <1 year: SBP <60 mmHg - 1–10 years: (age in years × 2) + 70 - >10 years: SBP <90 mmHg

EMT-B scope: - Administer oxygen (titrate SpO2 ≥94%) - ETCO2 monitoring - Transport without delay - Point-of-care BGL and serum lactate if available - Antipyretics for fever if able to tolerate PO: Acetaminophen 15 mg/kg (max 650 mg); Ibuprofen 10 mg/kg (max 600 mg) if >6 months

IV fluid resuscitation (ALS scope; EMT-B establishes access): - IV access; if unable within 2 attempts or <90 seconds → IO needle - 20 mL/kg isotonic fluid, max 1 liter over <15 minutes - Use pressure infuser or push-pull method - May repeat up to 3 times

Etiology-specific management: - Adrenal insufficiency history: METHYLPREDNISOLONE 2 mg/kg IV/IO (max 125 mg) or DEXAMETHASONE 10 mg IV/IO/IM adults; 0.6 mg/kg IV/IO/IM pediatric (ALS) - Anaphylactic shock: see Allergic Reaction/Anaphylaxis guideline — epinephrine first - Cardiogenic/hypovolemic/obstructive shock (ALS vasopressors): - NOREPINEPHRINE: 4 mcg/min IV/IO infusion (preferred per recent evidence) - DOPAMINE: 5–20 mcg/kg/min IV/IO - EPINEPHRINE: 0.05–0.3 mcg/kg/min IV/IO - Distributive shock (except anaphylaxis): NOREPINEPHRINE preferred (first-line for neurogenic shock) - Sepsis trigger: Hospital Sepsis Alert

NREMT Relevance

High-priority NREMT topic: - Recognize compensated shock (normal BP, tachycardia, pale skin, anxiety) - Decompensated shock = hypotension (BP drop is LATE sign in adults, VERY late in children) - Skin assessment: pale/cool/moist = classic shock; hot/flushed = early distributive - Treatment priority: hemorrhage control → O2 → position → rapid transport → fluid resuscitation - Do NOT delay transport for IV access - Pediatric: kids maintain BP longer; tachycardia + poor perfusion signs = suspect shock even with normal BP - Anaphylactic shock: epinephrine IM first; fluids second - Cardiogenic shock: avoid excessive fluids; may worsen pulmonary edema

Related

• shock-physiology — pathophysiology: cellular mechanism, 4 types, compensated vs. decompensated vs. irreversible stages, why tachycardia precedes hypotension
• bleeding-control-shock — hemorrhage control procedure details
• anaphylaxis — anaphylactic shock management with epinephrine
• primary-assessment — circulation assessment; hemorrhage identified here
• secondary-assessment — vital signs, skin assessment, cap refill
• reassessment — serial vital signs every 5 min in shock; watch for deterioration

Sources

• raw/protocols/nm-sop-guidelines-treatment-2022.pdf — Shock protocol (p. 57–58)