What is the guideline-based treatment for hypotension?

Guideline-Based Treatment for Hypotension

The most critical first step in treating hypotension is identifying the underlying physiological cause—vasodilation, hypovolemia, bradycardia, or low cardiac output—because only approximately 50% of hypotensive patients respond to fluids, and cause-directed treatment fundamentally differs based on etiology. 1, 2

Initial Assessment and Diagnostic Approach

Before administering any treatment, determine the mechanism of hypotension through rapid bedside evaluation:

• Perform a passive leg raise (PLR) test before giving fluids to assess fluid responsiveness, as this test has a positive likelihood ratio of 11 (95% CI: 7.6-17) with 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 of fluids (negative likelihood ratio 0.13) 1
• Measure blood pressure after having the patient sit or lie for 5 minutes, then remeasure at 1 and/or 3 minutes after standing to assess for orthostatic hypotension 3

Cause-Directed Treatment Algorithm

For Vasodilation (Normal/High Cardiac Output, Low Systemic Vascular Resistance)

• Administer norepinephrine as the first-line vasopressor for vasodilatory hypotension 2, 4
• Norepinephrine is FDA-approved for blood pressure control in acute hypotensive states including septicemia, spinal anesthesia, myocardial infarction, and drug reactions 4
• Phenylephrine is preferred when hypotension occurs with tachycardia, as it causes reflex bradycardia 1

For Hypovolemia (Low Cardiac Output, Low Filling Pressures)

• 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 2
• In pediatric patients, administer 10-20 mL/kg normal saline (maximum 1,000 mL) 1
• Avoid additional fluid boluses in patients with cardiac dysfunction or signs of volume overload (pulmonary edema) 1, 2

For Bradycardia (Heart Rate <60 with Hypotension)

• Administer atropine or glycopyrronium as first-line treatment for bradycardia-induced hypotension 1, 2
• Use epinephrine or isoprenaline if refractory to anticholinergics 1
• Consider cardiac pacing for profound bradycardia 1

For Low Cardiac Output (Myocardial Dysfunction)

• Administer dobutamine or epinephrine as positive inotropes for hypotension from myocardial dysfunction 1, 2
• In acute heart failure with hypoperfusion, levosimendan can reverse beta-blockade effects, but avoid if systolic BP <85 mmHg unless combined with other inotropes or vasopressors 1
• Do not use inotropic agents if the underlying cause is hypovolemia or other correctable factors until these are eliminated 1

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

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
• Aggressive fluid resuscitation increases mortality in this population 1, 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 1, 2

Acute Heart Failure with Hypoperfusion

• Avoid diuretics until adequate perfusion is attained 1
• Use beta-blockers cautiously if the patient is hypotensive 1
• In patients with evidence of severely symptomatic fluid overload without systemic hypotension, vasodilators (IV nitroglycerin, nitroprusside, or nesiritide) can be added to diuretics 3

Orthostatic Hypotension

• Pursue non-pharmacological approaches as first-line treatment for orthostatic hypotension in patients with supine hypertension 3
• Switch BP-lowering medications that worsen orthostatic hypotension to alternative therapy rather than simply de-intensifying treatment 3

Monitoring Recommendations

• 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
• Avoid abrupt withdrawal of vasopressor infusions; reduce gradually 1
• Monitor fluid intake/output, vital signs, daily weights, and clinical signs of perfusion and congestion 3
• Measure daily serum electrolytes, urea nitrogen, and creatinine during IV diuretic use or active medication titration 3

Critical Pitfalls to Avoid

• Do not reflexively administer fluids without assessing fluid responsiveness—approximately 50% of hypotensive patients are not hypovolemic and require vasopressors or inotropes instead 1, 2
• Postoperative hypotension is often unrecognized and may be more important than intraoperative hypotension because it is prolonged and untreated 1
• When hypotension persists despite dopamine infusion, discontinue dopamine and administer a more potent vasoconstrictor such as norepinephrine 5
• If using dopamine and hypotension persists at lower infusion rates, rapidly increase the rate until adequate blood pressure is obtained 5