How to manage a patient presenting with hypotension?

Management of Hypotension

Assess hypotension based on symptoms and organ perfusion rather than absolute blood pressure values alone, and immediately identify the underlying cause—hypovolemia, cardiogenic shock, septic shock, or medication-related—to guide targeted treatment. 1

Initial Assessment and Diagnosis

Blood Pressure Verification

• Confirm hypotension by measuring blood pressure in both supine/sitting and standing positions to detect orthostatic hypotension (drop ≥20 mmHg systolic and/or ≥10 mmHg diastolic within 3 minutes of standing) 2, 1
• Systolic BP <90 mmHg or mean arterial pressure <65 mmHg generally defines hypotension, though systolic BP <80 mmHg or any hypotension causing major symptoms requires immediate intervention 2, 1

Assess for End-Organ Hypoperfusion

Evaluate for signs of inadequate tissue perfusion rather than relying solely on blood pressure numbers 2, 1:

• Altered mental status (confusion, lethargy, irritability) 2, 1
• Oliguria (urine output <0.5 mL/kg/hr) 2, 1
• Cool, clammy skin and decreased capillary refill 2, 1
• Worsening renal function (rising creatinine) 1
• Cardiac ischemia (chest pain, ECG changes) 1

Identify the Underlying Cause

Hypovolemic causes (most common) 1:

• Acute fluid losses from diarrhea, vomiting, fever 1
• Excessive diuretic therapy 1
• Hemorrhage (trauma, GI bleeding) 2

Medication-related causes 1:

• Antihypertensive medications (ACE inhibitors, ARBs, calcium channel blockers, alpha-blockers) 1
• Beta-blockers, especially those with alpha-blocking properties like carvedilol 1
• Aggressive diuretic use 1

Cardiogenic shock 2, 1:

• Systolic BP <90 mmHg with central filling pressure >20 mmHg or cardiac index <1.8 L/min/m² 2, 1
• Extensive left ventricular damage, acute MI, severe valvular dysfunction 2

Septic shock 1:

• Sepsis requiring vasopressors to maintain MAP ≥65 mmHg and serum lactate >2 mmol/L despite adequate volume resuscitation 1

Other causes to exclude 2:

• Vasovagal reactions 2
• Electrolyte disturbances 2
• Arrhythmias 2

Treatment Algorithm

Step 1: Fluid-Responsive Hypotension (Hypovolemia)

For suspected hypovolemia without volume overload 2:

• Administer initial normal saline bolus 10-20 mL/kg (maximum 1,000 mL) over 30-60 minutes in adults 2, 1
• Perform passive leg raise (PLR) test to predict fluid responsiveness: increase in cardiac output after PLR strongly predicts fluid responsiveness (positive likelihood ratio=11, pooled specificity 92%) 2
• If PLR test is positive and hypotension persists, repeat fluid boluses 2
• Target MAP 65-70 mmHg initially 1

Critical caveat: Avoid additional fluid boluses in patients with 2:

• Underlying cardiac dysfunction 2
• Signs of volume overload (pulmonary edema, elevated jugular venous pressure) 2
• Risk of capillary leak syndrome (as in cytokine release syndrome) 2

Step 2: Non-Fluid-Responsive Hypotension (Vasopressor Support)

If PLR test is negative or hypotension persists despite adequate fluid resuscitation 2, 1:

Norepinephrine is the first-line vasopressor 1, 3:

• Dilute 4 mg norepinephrine in 1,000 mL of 5% dextrose solution (4 mcg/mL) 3
• Start at 2-3 mL/minute (8-12 mcg/minute), then titrate to maintain systolic BP 80-100 mmHg 3
• Average maintenance dose: 0.5-1 mL/minute (2-4 mcg/minute) 3
• Administer through large central vein with IV drip chamber for accurate flow rate 3
• In previously hypertensive patients, raise BP no higher than 40 mmHg below pre-existing systolic pressure 3

Avoid routine vasopressor use in hemorrhagic shock 2:

• Vasopressors are contraindicated in elderly trauma patients with hypotension from hemorrhage 2
• Identify and control bleeding source first 2

Step 3: Cardiogenic Shock Management

For hypotension with signs of poor cardiac output 2:

• Administer oxygen and obtain echocardiography to assess ventricular function 2
• Give intravenous nitroglycerin starting at 0.25 μg/kg/min if not hypotensive, increasing every 5 minutes until systolic BP falls to 90 mmHg 2
• Consider loop diuretic if pulmonary congestion present 2

Inotropic support when hypotension persists 2:

• Dobutamine 2.5-10 μg/kg/min if pulmonary congestion is dominant 2
• Dopamine 2.5-5.0 μg/kg/min if renal hypoperfusion is present 2
• Use only when depressed BP is associated with cold clammy skin, cool extremities, decreased urine output, or altered mentation 2

Critical warning: Inotropic agents portend poor prognosis; ensure low output syndrome is truly responsible before initiating 2

Step 4: Orthostatic Hypotension Management

Non-pharmacologic measures (first-line) 1, 4:

• Increase salt and fluid intake (if not contraindicated) 1, 4
• Elevate head of bed 10-20 degrees at night 4
• Physical countermaneuvers (leg crossing, squatting) 4
• Compression stockings 4

Pharmacologic therapy for persistent symptomatic orthostatic hypotension 1, 5, 4:

• Midodrine 2.5-10 mg three times daily (FDA-approved) 1, 5, 4
  • Start at 2.5 mg in patients with renal impairment 5
  • Take last dose 3-4 hours before bedtime to minimize supine hypertension 5
  • Monitor for bradycardia, urinary retention, and supine hypertension 5
• Droxidopa as alternative FDA-approved option 1, 4
• Fludrocortisone may be added but increases risk of supine hypertension 4

Special Population Considerations

Elderly and Frail Patients

• Screen for orthostatic hypotension before starting or intensifying BP medications 1
• Carefully evaluate permissive hypotension strategies, monitoring base excess, lactate, and urine output 2
• Avoid routine vasopressors in hemorrhagic shock 2

Heart Failure Patients

• Assess organ perfusion rather than relying solely on BP values 2
• Hypotension with minor symptoms is not a reason to withhold guideline-directed medical therapy 2
• Consider early use of colloid solutions if capillary leak suspected 2

Pediatric Patients (CAR T-cell therapy context)

• Define baseline BP range before treatment to detect relative hypotension 2
• Assess diapers in infants for urine output and diarrhea 2
• Consider adrenal insufficiency and use stress-dose hydrocortisone if vasopressor-resistant 2

Critical Pitfalls to Avoid

• Do not rely on single hematocrit measurements to assess bleeding, as initial values do not reflect acute blood loss 2
• Do not administer vasopressors before correcting volume depletion in hemorrhagic or hypovolemic shock 2, 3
• Do not use specific BP thresholds alone to dictate inotrope use; assess for signs of hypoperfusion 2
• Avoid abrupt withdrawal of vasopressor infusions; taper gradually 3
• Monitor for supine hypertension when treating orthostatic hypotension pharmacologically 5, 4