Medications for Hypotension Management
For hypotension management, norepinephrine is the first-line vasopressor therapy (0.05-2 mcg/kg/min), starting at 8-12 mcg/min, to maintain a mean arterial pressure ≥65 mmHg. 1
Assessment of Hypotension
Before initiating treatment, it's crucial to determine the cause of hypotension:
Check volume status:
- Perform passive leg raise test to assess fluid responsiveness
- Use bedside echocardiography to evaluate cardiac function and volume status 1
Identify hypotension type:
- Distributive shock (sepsis, anaphylaxis)
- Cardiogenic shock (heart failure)
- Hypovolemic shock (hemorrhage, dehydration)
- Obstructive shock (pulmonary embolism, cardiac tamponade)
Treatment Algorithm
Step 1: Initial Management
- Fluid resuscitation: Administer 10-20 mL/kg balanced crystalloids for volume depletion 1
- Position patient: Semi-recumbent or supine with legs elevated
- Discontinue hypotension-inducing medications if possible
Step 2: Pharmacological Management Based on Cause
For Distributive Shock:
- First-line: Norepinephrine (0.05-2 mcg/kg/min) 2, 1
- For refractory shock: Add vasopressin (up to 0.03 UI/min) 2, 3
For Cardiogenic Shock:
- First-line: Dobutamine (2-20 μg/kg/min) for inotropic support 2
- For persistent hypotension: Add norepinephrine 2
- For bradycardia: Consider dopamine 2
For Orthostatic Hypotension:
- First-line: Midodrine (starting dose 2.5-5 mg three times daily) 4, 5
- Monitor for supine hypertension
- Take last dose 3-4 hours before bedtime
- Alternative: Fludrocortisone for volume expansion 5
Step 3: Special Considerations
- Trauma patients: Use restricted volume replacement with permissive hypotension (SBP 80-90 mmHg) until bleeding is controlled 1
- Elderly patients: May benefit from lower MAP targets (60-65 mmHg) 1
- Patients with chronic hypertension: May require higher MAP targets (75-85 mmHg) 1
- Heart failure patients: Carefully balance hypotension management with HF medications 6
Medication Selection Guide
| Medication | Dosage | Primary Indication | Key Considerations |
|---|---|---|---|
| Norepinephrine | 0.05-2 mcg/kg/min | First-line vasopressor | Peripheral IV access acceptable initially but central line preferred for ongoing use [2] |
| Phenylephrine | Variable | Afterload-dependent states | Useful when tachycardia is present; causes reflex bradycardia [2] |
| Vasopressin | Up to 0.03 UI/min | Refractory shock | Reduces norepinephrine requirements [2,3] |
| Dopamine | 3-5 μg/kg/min (inotropic) | Hypotension with bradycardia | Higher doses (>5 μg/kg/min) have vasopressor effects [2] |
| Dobutamine | 2-20 μg/kg/min | Cardiogenic shock | Use when myocardial depression is present [2] |
| Midodrine | 2.5-10 mg TID | Orthostatic hypotension | Avoid in urinary retention; last dose 3-4 hours before bedtime [4] |
Important Caveats and Pitfalls
- Avoid excessive fluid administration in patients with cardiac dysfunction 1
- Don't delay vasopressor initiation while waiting for complete fluid resuscitation in severe hypotension 1
- Test for orthostatic hypotension before starting or intensifying BP medications 2
- Monitor for supine hypertension with midodrine therapy 4
- Avoid rapid BP correction in chronic hypotension as it may lead to organ damage 7
- Consider drug interactions: Midodrine can interact with other vasoconstrictors, cardiac glycosides, and psychopharmacologic agents 4
For patients with traumatic brain injury, maintaining systolic blood pressure >110 mmHg is critical as hypotension significantly worsens neurological outcomes 2.