Basic Shock Management Quiz
Question 1: Initial Fluid Resuscitation in Septic Shock
A 62-year-old patient presents with suspected septic shock with BP 85/50 mmHg, HR 115, lactate 4.2 mmol/L. What is the appropriate initial fluid bolus?
Correct Answer: At least 30 mL/kg of IV crystalloid fluid within the first 3 hours 111.
Critique of Answer:
This is the correct approach based on the 2016 Surviving Sepsis Campaign guidelines. For a 70 kg patient, this means approximately 2100 mL minimum within 3 hours. The guidelines specifically recommend crystalloids (either balanced crystalloids or saline) as first-line fluid 11.
Common pitfall: Giving inadequate initial volume or delaying fluid administration. Sepsis and septic shock are medical emergencies requiring immediate treatment 11. After this initial bolus, continue fluid administration using a fluid challenge technique as long as hemodynamic factors continue to improve 11.
Critical error to avoid: Using hydroxyethyl starches, which are strongly contraindicated in septic shock (strong recommendation, high quality evidence) 111. Albumin may be added only when patients require substantial amounts of crystalloids 11.
Question 2: First-Line Vasopressor Selection
After adequate fluid resuscitation, a patient with distributive shock remains hypotensive with MAP 58 mmHg. Which vasopressor should be started first?
Correct Answer: Norepinephrine 112.
Critique of Answer:
Norepinephrine is unequivocally the first-choice vasopressor (strong recommendation, moderate quality evidence) 11. This applies to both septic shock specifically and distributive shock generally 2.
Target MAP: Initially aim for ≥65 mmHg 113. However, individualize this target—consider higher MAP (65-70 mmHg) in patients with chronic hypertension who show clinical improvement with higher pressures 3.
Wrong choices and why:
- Dopamine: Only for highly selected patients with low risk of tachyarrhythmias and absolute or relative bradycardia 11
- Phenylephrine: Reserved for salvage therapy or when norepinephrine causes serious arrhythmias 11
- Low-dose dopamine: Never use for "renal protection" (strong recommendation against) 11
Question 3: Cardiogenic Shock Vasopressor Choice
A 58-year-old with acute MI develops cardiogenic shock with BP 78/45 mmHg, HR 125, cool extremities, and echocardiography showing severely reduced ejection fraction. After initial stabilization, which vasopressor is preferred if tachycardia is present?
Correct Answer: Norepinephrine 2.
Critique of Answer:
In cardiogenic shock with tachycardia, norepinephrine is the recommended vasopressor 2. The key distinction here is the heart rate.
Algorithm for cardiogenic shock vasopressor selection:
- If tachycardia present: Use norepinephrine 2
- If bradycardia present: Consider dopamine 2
- For inotropic support: Dobutamine or milrinone (both have similar outcomes, though milrinone has longer half-life and more profound hypotension) 2
Special considerations: In afterload-dependent states (aortic stenosis, mitral stenosis), phenylephrine or vasopressin is preferred 2. Avoid routine inotropes in heart failure without shock, as they increase mortality, but in cardiogenic shock they are necessary for organ perfusion 2.
Question 4: Shock Type Differentiation
A patient presents with hypotension, tachycardia, and altered mental status. Physical exam shows warm extremities and bounding pulses. What type of shock is this most consistent with?
Correct Answer: Distributive shock.
Critique of Answer:
This clinical picture—hypotension with warm extremities and bounding pulses—is pathognomonic for distributive shock 456.
Key differentiating features by shock type:
Distributive shock: Warm skin, bounding pulses, wide pulse pressure (early), pathological vasodilation 67
Hypovolemic shock: Cool extremities, weak pulses, narrow pulse pressure, signs of volume loss 67
Cardiogenic shock: Cool extremities, weak pulses, elevated JVP, pulmonary edema, signs of cardiac dysfunction 67
Obstructive shock: Depends on cause—distended neck veins (tamponade, tension pneumothorax, PE), unilateral breath sounds (tension pneumothorax) 67
Next step: Use echocardiography as first-line imaging to assess shock type and hemodynamic status 3. If clinical examination doesn't lead to clear diagnosis, perform further hemodynamic assessment to determine shock type 113.
Question 5: Lactate-Guided Resuscitation
A septic shock patient has received 30 mL/kg crystalloid and norepinephrine, achieving MAP 68 mmHg. Initial lactate was 5.8 mmol/L. What should guide further resuscitation?
Correct Answer: Target normalization of lactate as a marker of tissue hypoperfusion 11.
Critique of Answer:
Lactate normalization should guide ongoing resuscitation (weak recommendation, low quality evidence) 11. Even though MAP target is achieved, elevated lactate indicates persistent tissue hypoperfusion requiring continued intervention.
Resuscitation approach:
- Continue fluid challenge technique as long as hemodynamic factors improve 11
- Use dynamic variables (pulse pressure variation, stroke volume variation) over static variables to predict fluid responsiveness where available 11
- Reassess frequently using clinical examination and physiologic variables (heart rate, blood pressure, oxygen saturation, respiratory rate, temperature, urine output) 11
Important note: The 2016 guidelines moved away from the rigid 2012 targets (CVP 8-12 mmHg, ScvO2 70%) toward a more dynamic, individualized approach based on continuous reassessment 181.
Question 6: Adding Second Vasopressor
A septic shock patient on norepinephrine 0.4 mcg/kg/min still has MAP 62 mmHg despite adequate fluid resuscitation. What should be added next?
Correct Answer: Vasopressin up to 0.03 units/min OR epinephrine 11.
Critique of Answer:
Either vasopressin (up to 0.03 U/min) or epinephrine can be added to norepinephrine (weak recommendations, moderate and low quality evidence respectively) 11. Vasopressin can raise MAP to target OR decrease norepinephrine dosage, and may reduce renal replacement therapy requirements 2.
Dosing specifics:
- Vasopressin: Maximum 0.03-0.04 units/min; higher doses reserved for salvage therapy 11
- Never use vasopressin alone as single initial vasopressor 11
Alternative consideration: If myocardial depression is present with decreased perfusion, consider adding dobutamine to norepinephrine OR using epinephrine as single agent 2.
Wrong answer: Phenylephrine should be reserved for salvage therapy only 2.
Question 7: Source Control Timing
A patient with septic shock is found to have a large intra-abdominal abscess on CT. When should definitive source control intervention occur?
Correct Answer: As soon as medically and logistically practical after diagnosis 81.
Critique of Answer:
Source control should be implemented immediately once diagnosed (best practice statement) 81. This is a critical, time-sensitive intervention that directly impacts mortality.
Source control principles:
- Identify or exclude anatomic diagnosis requiring emergent source control as rapidly as possible 81
- Use the intervention with least physiologic insult (e.g., percutaneous drainage over surgical drainage when feasible) 1
- Exception: Infected peripancreatic necrosis—delay definitive intervention until adequate demarcation of viable/nonviable tissue 1
Intravascular access devices: If possible source of sepsis/septic shock, remove promptly after establishing other vascular access 81.
Question 8: Hemorrhagic Shock Management
A trauma patient with hemorrhagic shock has ongoing bleeding. What is the primary therapeutic goal?
Correct Answer: Restoration of blood volume AND definitive control of bleeding 2.
Critique of Answer:
Both volume restoration and hemorrhage control are equally critical and must occur simultaneously 2. This is fundamentally different from other shock types where the primary intervention is medical rather than procedural.
Vasopressor role in hemorrhagic shock: Vasopressors can be used transiently in life-threatening hypotension 2. Animal studies and small clinical trials suggest vasopressin with rapid hemorrhage control may improve blood pressure without increasing blood loss, potentially improving outcomes 2.
Critical distinction: Unlike distributive shock where vasopressors are first-line after fluids, in hemorrhagic shock they are temporizing measures only. Definitive treatment is surgical/interventional hemorrhage control.
Pitfall to avoid: Over-reliance on vasopressors without addressing the bleeding source leads to continued hemorrhage and death.
Question 9: Obstructive Shock Recognition
A post-operative cardiac surgery patient develops sudden hypotension, elevated JVP, muffled heart sounds, and pulsus paradoxus. What type of shock and immediate intervention?
Correct Answer: Obstructive shock (cardiac tamponade); immediate pericardiocentesis or surgical drainage.
Critique of Answer:
This is cardiac tamponade causing obstructive shock—a true emergency requiring immediate mechanical intervention 6. Obstructive shock arises from blockage of circulation with elevated resistance 6.
Obstructive shock causes and interventions:
- Cardiac tamponade: Pericardiocentesis or surgical drainage
- Tension pneumothorax: Needle decompression then chest tube
- Massive pulmonary embolism: Thrombolysis, embolectomy, or ECMO
- Severe aortic stenosis: Valve replacement (not acute intervention)
Key principle: Hypoperfusion due to elevated resistance requires immediate life-saving intervention to remove the obstruction 6. Medical management alone is insufficient.
Monitoring consideration: In refractory shock with RV dysfunction, use pulmonary artery catheterization for ongoing assessment 3.
Question 10: Hemodynamic Monitoring in Complex Shock
A patient with septic shock and severe ARDS (P/F ratio 120) on high-dose norepinephrine shows persistent hypotension despite aggressive resuscitation. What hemodynamic monitoring should be used?
Correct Answer: Transpulmonary thermodilution (preferred) OR pulmonary artery catheter 3.
Critique of Answer:
In severe shock with ARDS, advanced hemodynamic monitoring with transpulmonary thermodilution or PAC is recommended 3.
Decision algorithm for monitoring device:
Transpulmonary thermodilution preferred when:
- Moderate-to-severe ARDS without RV failure (measures extravascular lung water) 3
- Need for cardiac output monitoring in complex patients 3
Pulmonary artery catheter preferred when:
- RV failure present (measures pulmonary artery pressure) 3
- Refractory shock with RV dysfunction 3
- Persistent shock after cardiac surgery with RV failure 3
Echocardiography role: Use as first-line imaging to assess shock type and hemodynamic status 3. Serial evaluations provide additional cardiac function information even when CO is monitored 3.
Less invasive devices: Only use if validated specifically in shock context for that patient population 3.