What are the necessary steps before administering vasopressors (vasoconstrictor medications) to a patient with hypotension (low blood pressure)?

Pre-Vasopressor Checklist for Hypotension

Before initiating vasopressors, you must aggressively correct hypovolemia with at least 30 mL/kg of crystalloid fluid resuscitation, as inadequate volume replacement is the most common reason for vasopressor failure and can lead to profound tissue ischemia. 1

Critical Steps Before Starting Vasopressors

1. Fluid Resuscitation (Mandatory First Step)

• Administer a minimum of 30 mL/kg of crystalloid fluids as an initial fluid challenge in patients with sepsis-induced tissue hypoperfusion and suspected hypovolemia 1
• Continue fluid administration as long as hemodynamic improvement occurs, using either dynamic parameters (pulse pressure variation, stroke volume variation) or static variables (arterial pressure, heart rate) 1
• Blood volume depletion must be corrected as fully as possible before any vasopressor is administered, though in emergency situations where cerebral or coronary ischemia is imminent, vasopressors can be started concurrently with volume replacement 2

2. Assess Fluid Responsiveness

• Use passive leg raising (PLR) with cardiac output monitoring as the most reliable method to predict fluid responsiveness in awake patients on vasopressors 3
• For mechanically ventilated, apneic patients on vasopressors, point-of-care echocardiography measuring vena caval diameter changes with positive pressure breaths is the best choice 3
• Recognize that continued fluid administration after initial resuscitation has a higher probability of causing tissue edema and hypoxemia than increasing oxygen delivery 3

3. Establish Vascular Access

• Obtain central venous access for norepinephrine administration whenever possible, though peripheral access can be used temporarily while awaiting central line placement 4, 2
• Insert a plastic intravenous catheter through a suitable bore needle well advanced centrally into a large vein, avoiding catheter tie-in techniques that promote stasis 2
• Avoid leg veins in elderly patients or those with occlusive vascular disease 2

4. Secure Arterial Monitoring

• Place an arterial catheter as soon as practical in all patients requiring vasopressors for continuous blood pressure monitoring 1
• This is essential for accurate titration and detecting rapid hemodynamic changes 5

5. Prepare Infusion Equipment

• Use an IV drip chamber or suitable metering device to permit accurate flow rate estimation 2
• Dilute norepinephrine in 5% dextrose solution or 5% dextrose with sodium chloride—administration in saline solution alone is not recommended due to oxidation and loss of potency 2
• Standard dilution: Add 4 mg/4 mL norepinephrine to 1000 mL of dextrose-containing solution (4 mcg/mL concentration) 2

6. Rule Out Occult Hypovolemia

• Central venous pressure monitoring is helpful in detecting and treating occult blood volume depletion, especially when patients require unusually high vasopressor doses 2
• If the patient remains hypotensive despite escalating vasopressor doses, always suspect and correct ongoing volume depletion 2

Common Pitfalls to Avoid

• Never use vasopressors as a substitute for adequate fluid resuscitation—this leads to excessive vasoconstriction and organ ischemia without addressing the underlying hypovolemia 1, 2
• Do not delay vasopressor initiation excessively in profoundly hypotensive patients, as the extent and duration of hypotension are critical determinants of mortality 6
• Avoid administering whole blood or plasma through the same line as vasopressors—use separate access (such as a Y-tube) if given simultaneously 2
• Do not use dopamine for renal protection—this practice is strongly discouraged and provides no benefit 1

Target Parameters Before Starting Vasopressors

• Initial MAP target: 65 mmHg once vasopressors are initiated 1, 5
• In previously hypertensive patients, raise blood pressure no higher than 40 mmHg below the pre-existing systolic pressure 2
• Supplement blood pressure targets with assessment of regional perfusion: lactate levels, skin perfusion, mental status, and urine output 1, 4

Emergency Exception

In life-threatening hypotension where cerebral or coronary ischemia is imminent, vasopressors may be started before complete volume resuscitation, but aggressive fluid administration must continue simultaneously 2, 6