Management of Hypotension

Step 1: Initial Assessment and General Principles

• Establish IV access; begin cardiac monitoring and pulse oximetry
• Assess blood glucose; provide oxygen supplementation
• Identify and treat the underlying cause simultaneously with resuscitation
• Target MAP ≥65 mmHg (in most contexts)

Step 2: Classify the Shock Type

Step 3: Fluid Resuscitation

• Crystalloids (balanced saline, e.g. lactated Ringer's or normal saline) are the standard first choice
• In septic shock: 30 mL/kg IV crystalloid is recommended in the first 3 hours for patients with hypotension or lactate >2 mmol/L, though modern practice is shifting toward dynamic, individualized fluid assessment guided by fluid responsiveness rather than fixed-volume protocols
• Excessive fluid is harmful: positive fluid balance is associated with increased mortality and renal failure in septic shock
• Fluid responsiveness should be assessed using dynamic markers (pulse pressure variation, passive leg raise) before additional boluses
• Colloids have not been shown to be superior to crystalloids for most patients

"Vasopressors are typically initiated when hemodynamic stability cannot be restored with fluid administration alone." - Miller's Anesthesia, 10e

Step 4: Vasopressor Therapy

First-Line: Norepinephrine

• Mechanism: Stimulates α-adrenergic receptors (peripheral vasoconstriction) + β1 (inotropic stimulation), raising MAP
• Indication: First-line vasopressor for septic shock and acute hypotension refractory to fluids
• Dose: Titrated IV infusion (typically 0.01-3 mcg/kg/min)
• Adverse effects: Bradycardia, arrhythmias, peripheral ischemia
• Tintinalli's Emergency Medicine: "Norepinephrine is recommended as the initial vasopressor of choice for treatment of severe sepsis and septic shock refractory to adequate fluid resuscitation"

Second-Line / Add-on Agents

Step 5: Cause-Specific Management

Septic Shock (Distributive)

1. 1-hour bundle: blood cultures, broad-spectrum antibiotics, 30 mL/kg crystalloid IV, vasopressors if MAP <65, lactate measurement
2. Norepinephrine = first-line vasopressor
3. Add vasopressin if norepinephrine dose escalating
4. Corticosteroids (hydrocortisone 200 mg/day) reduce vasopressor requirements and aid shock reversal; mortality benefit less clear
5. Source control where applicable (drain abscess, debride infected tissue)

Cardiogenic Shock

1. Norepinephrine is the first-line vasoactive agent per current guidelines
2. Add dobutamine or milrinone for inotropic support (improves cardiac output)
3. Epinephrine, levosimendan, and milrinone are alternatives
4. Intra-aortic balloon pump (IABP) or other mechanical circulatory support if refractory
5. Treat underlying cause (urgent PCI for STEMI-related shock, cardioversion for arrhythmias)

Obstructive Shock

• Pulmonary embolism with hemodynamic instability: IV saline with caution (excessive fluids worsen RV failure), systemic thrombolysis or catheter-directed therapy; norepinephrine as vasopressor
• Tension pneumothorax: Immediate needle decompression followed by chest drain
• Cardiac tamponade: Emergency pericardiocentesis

Hypovolemic / Hemorrhagic Shock

• Rapid volume replacement with crystalloids; packed RBCs for hemorrhage
• Control the bleeding source
• Vasopressors are a temporary bridge; definitive management is volume and hemorrhage control

Anaphylactic Shock

• Epinephrine IM (0.3-0.5 mg, 1:1000) is the cornerstone treatment
• IV fluids, antihistamines, corticosteroids, and bronchodilators as adjuncts
• IV epinephrine infusion if refractory

Drug-Induced Hypotension (e.g., Antipsychotic Overdose)

• IV fluid resuscitation: 1-2 L crystalloid in adults (or 20-40 mL/kg in children)
• If refractory: direct-acting α-agonists (phenylephrine or norepinephrine) preferred
• Dopamine (indirect-acting) is not recommended after antipsychotic overdose
• Manage QT prolongation with IV magnesium sulfate 2 g if QTc >500 ms

Step 6: Orthostatic Hypotension (Chronic/Neurogenic)

• Patient education: rise slowly, avoid hot environments, large carbohydrate-rich meals, alcohol
• Increase salt intake (10-20 g/day) and fluid intake (2-2.5 L/day)
• Compression garments, postural countermaneuvers
• Elevate head of bed 30-45 degrees

Approach to orthostatic hypotension management - Goldman-Cecil Medicine

• Goldman-Cecil Medicine

Monitoring Targets

• Tintinalli's Emergency Medicine, Chapters 20, 15 (vasopressors, antipsychotic overdose)
• Miller's Anesthesia, 10e, Chapter 79 (sepsis/shock hemodynamic resuscitation)
• Goldman-Cecil Medicine, Chapter 366 (orthostatic hypotension)
• Rosen's Emergency Medicine, Frameworks for Internal Medicine (cardiogenic/obstructive shock)

Recent systematic review: Intraoperative hypotension management strategies (Lee et al., Anesth Analg 2025, PMID 38870081) confirms individualized blood pressure targets and vasopressor titration are superior to fixed thresholds in surgical patients.