What is the treatment for hypotension?

Treatment for Low Blood Pressure (Hypotension)

The treatment of hypotension depends entirely on the underlying cause—vasodilation requires vasopressors (norepinephrine first-line), hypovolemia requires fluids (only if fluid-responsive), bradycardia requires anticholinergics, and low cardiac output requires inotropes—making cause-directed therapy the cornerstone rather than empiric fluid administration. 1, 2

Critical First Step: Determine the Cause Before Treatment

Do not reflexively give fluids without assessing fluid responsiveness—approximately 50% of hypotensive patients are not hypovolemic and require vasopressors or inotropes instead. 1, 2

• Perform a passive leg raise (PLR) test before administering fluids to assess fluid responsiveness (positive likelihood ratio 11,92% specificity for predicting fluid response) 1, 2
• An increase in cardiac output after PLR indicates the patient will respond to fluids (88% sensitivity) 1
• No increase in cardiac output after PLR means the patient requires vasopressors or inotropes instead (negative likelihood ratio 0.13) 1, 2

Cause-Directed Treatment Algorithm

For Vasodilation (Most Common in Sepsis, Anesthesia)

• Administer norepinephrine as the first-line vasopressor 1, 3
• Norepinephrine should be diluted in 5% dextrose injection (4 mg/4 mL added to 1,000 mL) and given via central venous access 3
• Initial dose: 2-3 mL per minute (8-12 mcg of base), then titrate to maintain MAP ≥60 mmHg 3
• Average maintenance dose: 0.5-1 mL per minute (2-4 mcg of base); occasionally much higher doses may be necessary 3
• Phenylephrine is preferred when hypotension occurs with tachycardia, as it causes reflex bradycardia 1, 2

For Hypovolemia (Only if PLR Positive)

• Administer intravascular fluids (crystalloid, colloid, or blood products) only if PLR test is positive 1, 2
• Give an initial fluid bolus of 250-500 mL in adults 1
• In pediatric patients, administer 10-20 mL/kg normal saline (maximum 1,000 mL) 1, 2
• Avoid additional fluid boluses in patients with cardiac dysfunction or signs of volume overload (pulmonary edema) 1, 2

For Bradycardia-Induced Hypotension

• Administer anticholinergics (atropine or glycopyrronium) as first-line treatment 2
• Use epinephrine or isoprenaline if refractory to anticholinergics 2
• Consider pacing for profound bradycardia 2

For Low Cardiac Output (Myocardial Dysfunction)

• Administer positive inotropes: dobutamine or epinephrine 1, 2
• In acute heart failure with hypoperfusion, avoid diuretics until adequate perfusion is attained 1, 2
• Use beta-blockers cautiously if the patient is hypotensive 1, 2

Blood Pressure Targets

• Maintain mean arterial pressure (MAP) ≥60 mmHg in at-risk surgical patients, as MAP <60-70 mmHg or systolic BP <90-100 mmHg is associated with acute kidney injury, myocardial injury, and death 1, 2
• Increase MAP targets when venous or compartment pressures are elevated—add roughly the compartment pressure to your MAP target 1, 2
• In previously hypertensive patients, raise blood pressure no higher than 40 mm Hg below the preexisting systolic pressure 3

Context-Specific Modifications

Trauma Without Brain Injury

• Use a restricted volume replacement strategy targeting systolic BP 80-90 mmHg (MAP 50-60 mmHg) until major bleeding is controlled 1, 2
• Avoid aggressive fluid resuscitation—it increases mortality 2

Severe Traumatic Brain Injury

• Maintain MAP ≥80 mmHg to ensure adequate cerebral perfusion 1, 2
• Do not use permissive hypotension in traumatic brain injury 2

Orthostatic Hypotension (Chronic Symptomatic)

• Midodrine is FDA-approved for symptomatic orthostatic hypotension in patients whose lives are considerably impaired despite non-pharmacologic treatment 4
• Measure blood pressure after 5 minutes of sitting/lying, then at 1 and 3 minutes after standing to assess for orthostatic hypotension 1
• Midodrine should only be continued for patients who report significant symptomatic improvement 4

Monitoring Requirements

• Use continuous intraoperative arterial pressure monitoring to reduce severity and duration of hypotension compared to intermittent monitoring 1, 2
• Titrate vasoactive agents to effect rather than using fixed doses 1, 2
• Avoid abrupt withdrawal of vasopressor infusions; reduce gradually 1, 3
• Monitor fluid intake/output, vital signs, daily weights, and clinical signs of perfusion and congestion 1
• Measure daily serum electrolytes, urea nitrogen, and creatinine during active medication titration 1

Critical Pitfalls to Avoid

• Postoperative hypotension is often unrecognized and may be more important than intraoperative hypotension because it is prolonged and untreated 1, 2
• Blood volume depletion should always be corrected as fully as possible before any vasopressor is administered, except when intraaortic pressures must be maintained emergently to prevent cerebral or coronary artery ischemia 3
• Do not use inotropic agents in hypotensive acute heart failure where the underlying cause is hypovolemia or other potentially correctable factors before elimination of these causes 2