What are the new guidelines for managing hypotension (low blood pressure) in patients?

Management of Hypotension: 2024 Guidelines

Critical Initial Assessment and Etiology-Based Management

The first priority in managing hypotension is to identify and correct the underlying cause, with hemorrhagic hypotension requiring immediate volume resuscitation before any vasopressor therapy, while neurogenic shock may warrant early norepinephrine at the lowest effective dose. 1

Hemorrhagic Hypotension

• Vasopressors are strongly contraindicated as routine therapy in elderly trauma patients with hemorrhagic hypotension 1
• Blood volume depletion must be corrected as fully as possible before administering any vasopressor agent 2
• Norepinephrine should not be given to patients who are hypotensive from blood volume deficits except as an emergency measure to maintain coronary and cerebral perfusion until volume replacement is completed 2
• Continuous vasopressor administration without volume replacement causes severe peripheral vasoconstriction, decreased renal perfusion, tissue hypoxia, and lactate acidosis 2

Neurogenic Shock

• Norepinephrine is the recommended vasopressor for elderly patients with neurogenic shock, using the lowest dose necessary to guarantee tissue perfusion 1
• Monitor closely for cardiac arrhythmias and paradoxical hypotensive effects 1
• Identify the cause of hypoperfusion and assess preexisting conditions and medication history before selecting a vasopressor 1

Acute Hypotensive States (Non-Hemorrhagic)

• Norepinephrine is indicated for blood pressure control in acute hypotensive states including sympathectomy, spinal anesthesia, myocardial infarction, septicemia, and drug reactions 2
• For cardiac arrest with profound hypotension, norepinephrine serves as an adjunct to restore adequate blood pressure after effective heartbeat and ventilation are established 2

Norepinephrine Dosing Protocol

When norepinephrine is indicated 2:

• Dilute 4 mg/4 mL in 1,000 mL of 5% dextrose solution (4 mcg/mL concentration)
• Administer via large central vein with plastic IV catheter
• Initial dose: 8-12 mcg/minute (2-3 mL/minute)
• Maintenance dose: 2-4 mcg/minute (0.5-1 mL/minute)
• Target systolic BP: 80-100 mmHg in normotensive patients
• In previously hypertensive patients, raise BP no higher than 40 mmHg below preexisting systolic pressure
• Titrate according to individual response; occasionally doses up to 68 mg/day may be necessary if occult volume depletion is corrected

Permissive Hypotension in Selected Trauma Patients

• Carefully evaluate implementing permissive hypotension in selected elderly trauma patients with constant monitoring of tissue perfusion 1
• Monitor base excess, arterial lactate levels, urine output, and neurologic assessment 1
• This approach requires individualized assessment of bleeding control status and end-organ perfusion 1

Orthostatic Hypotension Management

Diagnostic Criteria and Testing

• Before starting or intensifying any BP-lowering medication, test for orthostatic hypotension by measuring BP after 5 minutes of sitting/lying, then at 1 and/or 3 minutes after standing 1
• Orthostatic hypotension is defined as a drop ≥20 mmHg systolic or ≥10 mmHg diastolic within 3 minutes of standing 3

Non-Pharmacological First-Line Treatment

• Non-pharmacological approaches are the recommended first-line treatment for orthostatic hypotension, especially in patients with supine hypertension 1
• Increase fluid intake to 2-3 liters daily and salt consumption to 6-9 grams daily (unless contraindicated by heart failure) 4
• Teach physical counter-maneuvers: leg crossing, squatting, stooping, and muscle tensing during symptomatic episodes 4
• Use waist-high compression stockings (30-40 mmHg) and abdominal binders to reduce venous pooling 4

Medication Management Strategy

• Switch BP-lowering medications that worsen orthostatic hypotension to alternative therapy rather than simply reducing dosage 1
• Discontinue or modify culprit medications (such as ropinirole) as the first-line approach 4
• For patients ≥85 years or with moderate-to-severe frailty, consider long-acting dihydropyridine CCBs or RAS inhibitors as first-line antihypertensives, avoiding beta-blockers and alpha-blockers unless specifically indicated 1, 5

Pharmacological Treatment for Persistent Orthostatic Hypotension

• Midodrine 2.5-5 mg three times daily is the first-line pressor agent, with the last dose at least 3-4 hours before bedtime to prevent supine hypertension 4
• Fludrocortisone 0.05-0.1 mg daily, titrated to 0.1-0.3 mg daily, is an alternative but should be avoided in heart failure or significant cardiac dysfunction 4
• Droxidopa is FDA-approved for neurogenic orthostatic hypotension 5

Special Population Considerations

Elderly and Frail Patients

• Screen for frailty using validated clinical tests before initiating BP treatment 1
• Assess early for delirium risk factors, as this correlates with unfavorable outcomes in geriatric trauma patients 1
• Consider deprescribing BP-lowering medications if BP drops with progressing frailty 1
• Elderly patients have substantially higher risk due to impaired baroreceptor response and altered pharmacokinetics 4

Patients on Anticoagulation

• Perform routine coagulation assays (aPTT, PT, INR, anti-Xa levels) in elderly trauma patients to assess anticoagulant exposure 1
• For life-threatening bleeding on vitamin K antagonists, administer four-factor prothrombin complex concentrates (4F-PCCs) plus 5 mg IV vitamin K, targeting INR <1.5 1

Monitoring and Follow-Up

• Monitor tissue perfusion continuously through base excess, lactate levels, urine output, and neurologic status 1
• Reassess within 1-2 weeks after initiating treatment for orthostatic hypotension to check symptoms and BP response 6
• Regular monitoring of both standing and supine blood pressure is essential 5
• Central venous pressure monitoring is helpful in detecting occult blood volume depletion in patients requiring high vasopressor doses 2

Critical Contraindications and Warnings

• Norepinephrine is contraindicated with cyclopropane and halothane anesthetics due to risk of ventricular arrhythmias 2
• Avoid norepinephrine in mesenteric or peripheral vascular thrombosis unless necessary as a life-saving procedure 2
• Do not use norepinephrine solutions that are pinkish, darker than slightly yellow, or contain precipitate 2
• Avoid contact with iron salts, alkalis, or oxidizing agents 2