Do we give vasopressors to patients with hypotension?

Vasopressor Use in Hypotensive Patients

Yes, vasopressors should be given to hypotensive patients, but only after adequate fluid resuscitation has been attempted, with norepinephrine as the first-line agent targeting a mean arterial pressure (MAP) ≥65 mmHg. 1, 2

Critical Pre-Vasopressor Requirements

Before initiating vasopressors, fluid resuscitation must be prioritized:

• Administer a minimum of 30 mL/kg of crystalloid fluid (balanced crystalloid or 0.9% saline) as the initial fluid challenge in patients with suspected hypovolemia 1, 2
• Blood volume depletion should be corrected as fully as possible before any vasopressor is administered 3
• Emergency exception: In situations where cerebral or coronary ischemia is imminent, vasopressors can be started concurrently with volume replacement rather than waiting for complete fluid resuscitation 1, 3

When to Initiate Vasopressors

The specific blood pressure threshold depends on the clinical context:

For Septic Shock and General Hypotension

• Start vasopressors when MAP remains <65 mmHg despite adequate fluid resuscitation 1, 2
• Initiate when signs of persistent tissue hypoperfusion are present (altered mental status, oliguria, elevated lactate) 2

For Hemorrhagic Trauma (Special Considerations)

• Avoid vasopressors if systolic BP 80-90 mmHg can be achieved with restricted volume replacement until bleeding is controlled 4
• Only add norepinephrine if systolic BP drops below 80 mmHg in trauma patients without traumatic brain injury (TBI) or spinal injury 4, 1
• Exception: In trauma patients with TBI or spinal injury, permissive hypotension is contraindicated—maintain adequate perfusion pressure immediately 4

First-Line Vasopressor Selection

Norepinephrine is the first-choice vasopressor for all forms of shock 1, 2:

• Starting dose: 0.02 mcg/kg/min, titrated to achieve target MAP 1
• Target MAP: ≥65 mmHg for most patients; may need 70-75 mmHg in patients with chronic hypertension 1
• Administration route: Via central venous line whenever possible, though can be started peripherally while awaiting central access 1

Essential Monitoring

Once vasopressors are initiated:

• Place an arterial catheter as soon as practical for continuous blood pressure monitoring 1, 2
• Monitor perfusion markers: lactate clearance, urine output (>0.5 mL/kg/h), mental status, skin perfusion, capillary refill 1, 2

Second-Line Vasopressor Options

If hypotension persists despite norepinephrine:

• Add vasopressin (up to 0.03 units/min) to increase MAP or reduce norepinephrine dose 1, 5
• Consider epinephrine as an alternative second agent, particularly when myocardial dysfunction is present due to its inotropic effects 1
• Add dobutamine (2.5-10 mcg/kg/min) if evidence of low cardiac output persists despite adequate MAP and fluid resuscitation 1, 6

Critical Pitfalls to Avoid

Do not use dopamine as a first-line agent—it increases arrhythmia risk compared to norepinephrine and should be reserved only for highly selected patients with bradycardia and low arrhythmia risk 1, 2:

• Never use low-dose dopamine for renal protection—it provides no benefit 4, 1, 6

Do not use vasopressors as a substitute for adequate fluid resuscitation in hypovolemic states—this leads to excessive vasoconstriction and organ ischemia without addressing the underlying volume deficit 1:

• In hemorrhagic trauma, premature vasopressor use when systolic BP is 80-90 mmHg may worsen organ perfusion through excessive vasoconstriction 4

Special Clinical Contexts

Trauma with Hemorrhagic Shock

The European trauma guidelines emphasize a restricted volume replacement strategy with permissive hypotension (systolic BP 80-90 mmHg) until bleeding is controlled 4:

• Transient norepinephrine is recommended only when systolic BP <80 mmHg to maintain life and tissue perfusion 4
• Consider low-dose arginine vasopressin (bolus of 4 IU followed by 0.04 IU/min) to decrease blood product requirements in severe hemorrhagic shock 4
• Add dobutamine if myocardial dysfunction is present 4

Peri-Intubation Hypotension

Evidence for vasopressor use during rapid sequence intubation is insufficient to make a definitive recommendation 4:

• Studies show mixed results regarding whether vasopressor boluses or fluid administration reduce cardiovascular instability during intubation 4
• Peri-intubation hypotension is associated with ICU mortality, but the optimal intervention remains undefined 4

Pediatric Septic Shock

In children with fluid-refractory shock 4:

• Begin peripheral inotropic support until central venous access can be attained—delay in inotrope use is associated with increased mortality 4
• Dopamine-refractory shock may reverse with epinephrine or norepinephrine infusion 4