Immediate Vasopressor Therapy with Norepinephrine
When a patient with severe hypotension (BP 60/40) fails to respond to an initial fluid bolus, immediately initiate norepinephrine as the first-line vasopressor to achieve a mean arterial pressure (MAP) ≥65 mmHg. 1, 2, 3
Critical Decision Point: Stop Fluids, Start Vasopressors
- Terminate further fluid resuscitation immediately when hypotension persists after adequate fluid challenge, as approximately 50% of hypotensive patients are not fluid-responsive and continued fluids risk pulmonary edema and worsening outcomes 1
- A BP of 60/40 (MAP approximately 47 mmHg) represents life-threatening hypotension requiring urgent vasopressor support 4
- The Surviving Sepsis Campaign guidelines mandate vasopressor initiation when MAP remains <65 mmHg despite adequate fluid resuscitation 4, 2
Norepinephrine Administration Protocol
- Start norepinephrine at 0.02 mcg/kg/min and titrate rapidly to achieve MAP ≥65 mmHg 1, 2
- Norepinephrine is recommended as the first-choice vasopressor by all major critical care societies for distributive, septic, and most forms of shock 1, 2, 3, 5, 6
- The FDA-approved dosing begins with 8-12 mcg/min (2-3 mL/min of standard 4 mcg/mL dilution), with average maintenance of 2-4 mcg/min 7
- Administer through a large central vein when possible, though peripheral access is acceptable initially if central access delays treatment 7
Concurrent Actions During Vasopressor Initiation
- Place an arterial line as soon as practical for continuous blood pressure monitoring in all patients requiring vasopressors 2
- Position the patient supine, as this improves MAP compared to semi-sitting positions 3
- Monitor for signs of adequate perfusion: improved mental status, capillary refill <3 seconds, urine output >0.5 mL/kg/hr, and lactate clearance 1, 2, 3
- Obtain arterial blood gas and serum lactate to assess tissue perfusion 3
Escalation Strategy if Inadequate Response
- If MAP remains <65 mmHg on norepinephrine alone, add vasopressin (0.03 units/min) as a second-line agent rather than escalating norepinephrine to extreme doses 3, 5
- Norepinephrine can be safely increased up to ≥1 mcg/kg/min in refractory cases, though doses this high (>0.5 mcg/kg/min) define refractory shock with mortality >50% 5, 8
- Consider adding dobutamine (2.5-10 mcg/kg/min) if cardiac dysfunction or low cardiac output is suspected after blood pressure stabilizes 3, 6
- Epinephrine may be added or substituted for norepinephrine in truly refractory shock 3, 9
Critical Pitfalls to Avoid
- Do not administer additional fluid boluses in a patient with BP 60/40 who has already received initial fluids without response—this delays definitive vasopressor therapy and risks fluid overload 1, 10
- Do not use dopamine as a first-line agent due to increased arrhythmia risk; it should be avoided except in highly selected patients with bradycardia 2, 3, 6
- Do not delay vasopressor initiation while attempting additional fluid challenges or waiting for central access—early vasopressor administration (within the first hour) improves outcomes 10
- Do not use low-dose dopamine for renal protection—this practice is ineffective and not recommended 2
Special Considerations by Etiology
- For anaphylactic shock: Administer intramuscular epinephrine 0.3-0.5 mg (1:1000) immediately in addition to IV vasopressors and fluids 3
- For traumatic hemorrhagic shock: Norepinephrine is recommended only if systolic BP <80 mmHg persists despite restricted volume replacement, as permissive hypotension (SBP 80-90 mmHg) is preferred until bleeding is controlled 4
- For severe traumatic brain injury: Target MAP ≥80 mmHg to ensure adequate cerebral perfusion pressure 1