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Management Protocol for All Types of Shock

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Overview: Classification of Shock

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Universal Initial Assessment (All Shock Types)

1. Airway - secure and protect; intubate if GCS <8 or unable to protect airway
2. Breathing - supplemental O2; target SpO2 >94%; consider early mechanical ventilation
3. Circulation - 2 large-bore IV lines; attach cardiac monitor; 12-lead ECG
4. Rapid assessment - HR, BP (both arms), RR, SpO2, temp, capillary refill, mental status
5. Point-of-care ultrasound (POCUS) - essential to differentiate shock type (cardiac function, IVC collapsibility, lung sliding, pericardial fluid)

• CBC, BMP, LFTs, coagulation panel (PT/INR/aPTT)
• Lactate (arterial or venous) - target clearance ≥10% per 2 hours
• ABG, blood type and crossmatch
• Blood cultures x2 (before antibiotics if infection suspected)
• Troponin, BNP/NT-proBNP

• MAP ≥65 mmHg (≥80 in neurogenic shock)
• Urine output ≥0.5 mL/kg/hr
• Lactate normalization (<2 mmol/L)
• ScvO2 >70% (via central venous catheter)
• SOFA score improvement

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1. HYPOVOLEMIC SHOCK

Pathophysiology

Causes

• Hemorrhagic: trauma, GI bleed, ruptured AAA, ectopic pregnancy, postpartum hemorrhage
• Non-hemorrhagic: burns, pancreatitis, GI losses (vomiting/diarrhea), renal losses (DI, adrenal crisis), third-spacing

ATLS Classification (Hemorrhagic Shock)

Management Protocol

• Surgical control of bleeding (hemorrhage control takes priority over resuscitation in penetrating trauma)
• Tourniquet for extremity hemorrhage
• Pressurize wound with direct pressure or hemostatic gauze

• Class I-II: Crystalloid (Lactated Ringer's preferred over normal saline - balanced solutions reduce hyperchloremic acidosis). 1-2 L bolus IV; reassess.
• Class III: Crystalloid + packed red blood cells (pRBCs). Balanced crystalloids (LR) preferred.
• Class IV (hemorrhagic): Damage Control Resuscitation (DCR):
  • 1:1:1 ratio of pRBCs : FFP : platelets
  • Permissive hypotension (target SBP 80-90 mmHg) until surgical hemorrhage control in penetrating trauma - avoid in TBI
  • Tranexamic acid (TXA) 1 g IV over 10 min, then 1 g over 8 hrs - give within 3 hours of injury
  • Avoid excessive crystalloid (associated with coagulopathy, hypothermia, acidosis - "lethal triad")
• Non-hemorrhagic: Crystalloid resuscitation; address underlying electrolyte abnormality (gastric vs. colonic losses differ)

• Norepinephrine 0.01-3 mcg/kg/min (first-line if MAP persistently <65 despite fluid)
• Vasopressors in hemorrhagic shock increase mortality - use sparingly and only after adequate volume replacement

• Urine output (Foley catheter)
• Serial lactate q2h
• Hgb/Hct, ionized calcium (hypocalcemia with massive transfusion)
• Temperature - keep warm; hypothermia worsens coagulopathy
• Calcium chloride 1 g IV per 4 units pRBC (for massive transfusion)

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2. CARDIOGENIC SHOCK

Pathophysiology

Causes

• Myocardial: Anterior wall MI (most common), non-ischemic cardiomyopathy, myocarditis, toxin/drug-induced (beta-blockers, CCBs, TCAs, anthracyclines), metabolic (hypocalcemia, hypophosphatemia, acidosis)
• Valvular: ruptured papillary muscle, acute MR, acute AS/AR
• Arrhythmic: VT/VF, complete heart block, severe bradycardia

Diagnosis

• Clinical: pulmonary rales, S3 gallop, JVD, pink frothy sputum, bilateral infiltrates on CXR
• Echo: reduced EF, wall motion abnormalities, valvular pathology
• Labs: elevated troponin, BNP; low ScvO2; rising lactate
• Hemodynamics: CI <2.2 L/min/m², PAOP >18 mmHg, MAP <65 mmHg

Management Protocol

• Ischemic/STEMI: Emergent PCI (primary reperfusion is the most important intervention). Fibrinolysis if PCI unavailable within 120 min.
• Arrhythmia: Cardioversion/defibrillation for VT/VF; pacing for complete heart block
• Mechanical complication (papillary rupture, VSD): Urgent surgical repair
• Non-ischemic decompensated HF: Beta-blockers and diuresis have an increasing role

• Fluid: Cautious fluid challenge (250 mL bolus); avoid aggressive loading (worsens pulmonary edema). Give only if PAOP/CVP low or patient appears volume-depleted.
• Vasopressors/Inotropes:
  • Norepinephrine 0.01-0.5 mcg/kg/min - first-line vasopressor (maintains MAP, less arrhythmogenic than dopamine)
  • Dobutamine 2-20 mcg/kg/min - add for inotropic support when CI is low and MAP acceptable
  • Epinephrine - avoid if possible; associated with poor short-term survival in cardiogenic shock
  • Vasopressin - second-line vasopressor; reduces catecholamine requirements
• Vasodilators (only in non-hypotensive patients): Nitroglycerin or sodium nitroprusside IV - reduce preload/afterload; contraindicated if SBP <90 mmHg

• Intra-aortic balloon pump (IABP): Reduces afterload, augments diastolic coronary perfusion. Used as bridge to PCI/surgery. Note: IABP-SHOCK II trial showed no mortality benefit over medical therapy alone.
• Impella (axial flow pump): Greater hemodynamic support than IABP; increasingly used as bridge to recovery or transplant
• VA-ECMO: For refractory cardiogenic shock; provides full cardiopulmonary bypass

• Diuresis (furosemide) once hemodynamically stable to reduce pulmonary congestion
• Intubation and mechanical ventilation if severe respiratory distress (reduces work of breathing and myocardial O2 demand)
• Avoid beta-blockers acutely in ischemic cardiogenic shock
• Avoid aggressive diuresis in RV infarction (RV is preload-dependent)
• For RV infarction: IV fluids cautiously, norepinephrine, avoid nitrates (reduce RV preload), maintain AV synchrony

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3. DISTRIBUTIVE SHOCK

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3a. SEPTIC SHOCK

Definition (Sepsis-3)

Management Protocol

1. Measure lactate; remeasure if initial >2 mmol/L
2. Blood cultures x2 before antibiotics
3. Broad-spectrum antibiotics within 1 hour
4. 30 mL/kg IV crystalloid for hypotension or lactate ≥4 mmol/L
5. Vasopressors if MAP <65 mmHg despite fluid resuscitation

• Empirical broad-spectrum coverage: piperacillin-tazobactam OR meropenem/imipenem (if high resistance risk)
• Add vancomycin if MRSA suspected (IV catheter infection, known colonization)
• Add antifungals if Candida risk factors (prolonged ICU, immunocompromised, TPN)
• De-escalate based on culture results (48-72 hrs)
• Duration: typically 7-10 days; shorter courses acceptable if clinically improved

• Drain abscesses, remove infected catheters, debride infected tissue
• Surgical intervention within 6-12 hours if indicated (perforated viscus, necrotizing fasciitis)

• 30 mL/kg balanced crystalloid (LR preferred over NS - reduces hyperchloremia and AKI)
• Reassess after each bolus with clinical exam, POCUS, pulse pressure variation
• Albumin 20-25% may be considered in patients who have received large crystalloid volumes
• Avoid starches (HES) - associated with increased AKI and mortality

• Norepinephrine: first-line, 0.01-3 mcg/kg/min via central venous catheter (or IO if no central access)
• Vasopressin 0.03-0.04 units/min: add to reduce norepinephrine dose (reduces catecholamine toxicity); second-line
• Epinephrine: third-line or when bradycardia coexists
• Dopamine: no longer recommended as first-line; associated with more arrhythmias
• Angiotensin II (Giapreza): for refractory vasodilatory shock

• Hydrocortisone 200 mg/day IV (continuous infusion or 50 mg q6h) if shock refractory to norepinephrine >0.25 mcg/kg/min for >4 hours
• Do NOT use dexamethasone (lacks mineralocorticoid effect)
• Taper when vasopressors weaned

• Target blood glucose 140-180 mg/dL
• Avoid tight glucose control (<110 mg/dL) - associated with hypoglycemia and harm

• Lung-protective ventilation if ARDS: TV 6 mL/kg ideal body weight, plateau pressure <30 cmH2O
• Prone positioning for P/F ratio <150
• Renal replacement therapy if refractory AKI with volume overload, acidosis, or hyperkalemia

• Lactate clearance ≥10% per 2 hours (target <2 mmol/L)
• ScvO2 >70%
• MAP ≥65 mmHg
• Urine output ≥0.5 mL/kg/hr

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3b. ANAPHYLACTIC SHOCK

Triggers

Diagnosis

• Skin/mucosal symptoms (urticaria, angioedema, flushing) PLUS respiratory compromise OR hypotension
• Two or more organ systems involved after allergen exposure
• Hypotension alone after known allergen exposure

Management Protocol

• IM epinephrine 0.3-0.5 mg (1:1000) in the anterolateral thigh - repeat every 5-15 min as needed (2-3 doses)
• If refractory or cardiovascular collapse: IV epinephrine 0.1-0.2 mg (1:10,000) slow IV push; then continuous infusion 0.1-1 mcg/kg/min
• Glucagon 1-2 mg IV/IM (for patients on beta-blockers who fail to respond to epinephrine - overcomes beta-blockade)

• Supine with legs elevated (improves venous return)
• Supplemental O2 via non-rebreather mask; prepare for early intubation (angioedema can progress rapidly)
• Cricothyrotomy tray at bedside if laryngeal edema severe

• 1-2 L crystalloid IV rapidly for hypotension
• Large volumes may be needed due to massive capillary leak

• H1 antihistamine: Diphenhydramine 25-50 mg IV (for urticaria/pruritus - does NOT prevent shock)
• H2 antihistamine: Ranitidine or famotidine IV (complementary)
• Corticosteroids: Methylprednisolone 125 mg IV or hydrocortisone 200 mg IV (prevent biphasic reaction, onset delayed 4-6 hrs)
• Bronchodilator: Salbutamol/albuterol nebulization for bronchospasm

• Observe minimum 4-6 hours (biphasic reactions in 5-20% of patients, occurring up to 72 hrs)
• Admit for: refractory hypotension, airway involvement, unknown trigger, IV epinephrine used
• Discharge: prescribe 2 self-injectable epinephrine devices (EpiPen), oral antihistamine, oral steroid course, allergist referral
• Medic alert bracelet

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3c. NEUROGENIC SHOCK

Pathophysiology

Diagnosis

• Classic triad: Hypotension + bradycardia + hypothermia
• Must be differentiated from hemorrhagic shock (also common in trauma patients with SCI)
• POCUS: normal/hyperdynamic cardiac function, non-collapsing IVC

Management Protocol

• Immobilize cervical spine
• Methylprednisolone: no longer routinely recommended (controversial; consider only within 8 hrs of injury per NASCIS-2 if institutional protocol)
• Maintain MAP 85-90 mmHg (higher target than other shock states to optimize spinal cord perfusion)

• Isotonic crystalloid to restore circulating volume
• Avoid over-resuscitation (patients may develop pulmonary edema without sympathetic tone)

• Norepinephrine or phenylephrine (alpha-1 agonists) - preferred; restore vascular tone
• Dopamine - useful if bradycardia is significant (has both alpha and beta-1 effects)
• Atropine 0.5-1 mg IV for symptomatic bradycardia; may need temporary transvenous pacing for refractory cases

• External warming (patients are poikilothermic below level of injury)

• MAP target 85-90 mmHg x 5-7 days to optimize cord perfusion
• Foley catheter (bladder dysfunction)
• Bowel care (paralytic ileus common)
• DVT prophylaxis (early, given high clot risk)

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3d. ENDOCRINE/ADRENAL CRISIS SHOCK

Causes

Diagnosis

Management Protocol

1. Do not wait for lab confirmation - treat empirically if clinical suspicion high
2. Hydrocortisone 100 mg IV bolus, then 50 mg IV q6h or 200 mg/day continuous infusion
3. Dextrose-containing fluid (D5NS or D5LR) - correct hypoglycemia
4. 1-2 L isotonic saline rapidly (correct hypovolemia and hyponatremia cautiously)
5. Vasopressors as needed (typically respond to steroids within 1-2 hrs)
6. Identify and treat precipitating cause (infection, surgery, trauma)

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4. OBSTRUCTIVE SHOCK

Pathophysiology

Hemodynamic Pattern

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4a. TENSION PNEUMOTHORAX

Diagnosis (clinical - DO NOT wait for CXR)

• Absent breath sounds unilaterally + tracheal deviation (late sign)
• Severe respiratory distress + hypotension + JVD
• POCUS: absent lung sliding on affected side; M-mode "barcode sign"

Management

1. Immediate needle decompression - 2nd intercostal space, midclavicular line (or 4th-5th ICS, anterior axillary line if obese) - 14G angiocath, minimum 8 cm length
2. Definitive treatment: chest tube thoracostomy - 4th or 5th ICS, anterior axillary line; 28-32Fr tube (trauma); or finger thoracostomy in cardiac arrest
3. Bilateral decompressions in traumatic arrest before thoracotomy
4. No time for imaging - treat clinically

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4b. CARDIAC TAMPONADE

Diagnosis

• Beck's triad: Hypotension + JVD + muffled heart sounds (classic but only present in 10-40%)
• Pulsus paradoxus >10 mmHg (exaggerated fall in SBP with inspiration)
• ECG: electrical alternans, low voltage, sinus tachycardia
• POCUS (diagnostic gold standard): Pericardial effusion + RV collapse in diastole + IVC dilation without respiratory variation; swinging heart

Management

1. Aggressive IV fluids to maintain preload while preparing for drainage
2. Pericardiocentesis (emergency or guided by echo):
   • Subxiphoid approach; aspirate 10-20 mL can restore hemodynamics dramatically
   • Echo-guided preferred if time allows (reduces complications)
3. Surgical pericardiotomy/window if: traumatic tamponade (clotted blood), recurrent tamponade, hemopericardium
4. Emergency thoracotomy in traumatic cardiac arrest with tamponade
5. Avoid positive pressure ventilation if possible (reduces venous return)
6. Avoid vasodilators and diuretics (both worsen preload)
7. Maintain heart rate (tachycardia is compensatory - do not give beta-blockers)

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4c. MASSIVE PULMONARY EMBOLISM

Diagnosis

• POCUS: RV enlargement (RV:LV ratio >0.9), septal bowing (D-sign), McConnell's sign, dilated IVC
• CT-PA (if stable enough): filling defect in main/bilateral PAs + RV strain
• ECG: S1Q3T3, new RBBB, sinus tachycardia

Management

1. Anticoagulation immediately (unless absolute contraindication): UFH 80 units/kg IV bolus, then 18 units/kg/hr infusion
2. Systemic thrombolysis (first-line reperfusion for massive PE):
   • Alteplase (tPA) 100 mg IV over 2 hrs (or 0.6 mg/kg over 15 min in cardiac arrest)
   • Contraindications: active bleeding, recent stroke, prior intracranial surgery, pregnancy
3. Surgical embolectomy: If thrombolysis is contraindicated or fails; requires cardiopulmonary bypass
4. Catheter-directed thrombolysis/thrombectomy (CDTT): For sub-massive PE or when systemic lysis is contraindicated; reduced dose tPA delivered directly into clot
5. Supportive care:
   • Cautious IV fluids (RV is dilated and failing; excessive fluids cause septal shift and LV compromise)
   • Vasopressors: norepinephrine first-line; vasopressin as adjunct
   • Avoid dobutamine alone (may cause systemic vasodilation)
   • Intubation: use carefully (positive pressure ventilation decreases venous return and can precipitate arrest)
   • VA-ECMO: bridge to surgical embolectomy in refractory cases

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Vasopressor/Inotrope Quick Reference

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Monitoring and Endpoints of Resuscitation

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SOFA Score (Sepsis Severity Assessment)

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Differential Diagnosis by POCUS

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What's Inside

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1. Pericardial effusion + RV collapse? → Tamponade
2. Absent lung sliding (barcode sign)? → Tension PTX
3. RV:LV >0.9 + D-sign + non-collapsible IVC? → Massive PE
4. EF <30% + dilated LV? → Cardiogenic shock
5. IVC small + collapsible (CI >50%)? → Hypovolemic; otherwise → Distributive