What is the treatment for hypotension?

Treatment of Hypotension

Hypotension treatment must be immediately directed at the underlying cause—vasodilation, hypovolaemia, bradycardia, or low cardiac output—rather than empirically administering fluids, as only approximately 50% of hypotensive patients are fluid-responsive. 1

Initial Assessment and Cause-Directed Treatment

Identify the Underlying Mechanism

The most critical first step is determining which physiological derangement is causing hypotension, as treatment differs fundamentally based on etiology 1:

• Vasodilation: Treat with vasopressors (phenylephrine or norepinephrine) 1, 2
• Hypovolaemia: Treat with intravascular fluid administration (crystalloid, colloid, or blood products) 1
• Bradycardia: Treat with anticholinergics (atropine, glycopyrronium), or epinephrine/isoprenaline if refractory; consider pacing for profound bradycardia 1
• Low cardiac output: Treat with positive inotropes (dobutamine or epinephrine) 1, 3

Passive Leg Raise (PLR) Test for Fluid Responsiveness

A PLR test should be performed before administering fluids to determine if hypovolaemia is contributing to hypotension. 1

• An increase in cardiac output after PLR strongly predicts fluid responsiveness (positive likelihood ratio = 11; 95% CI, 7.6-17; pooled specificity 92%) 1
• No increase in cardiac output after PLR indicates the patient will likely not respond to fluid (negative likelihood ratio = 0.13; 95% CI, 0.07-0.22; pooled sensitivity 88%) 1
• In postoperative patients with suspected hypovolaemia, only 54% actually respond to fluid boluses, meaning ~50% require correction of vascular tone or inotropy instead 1

If PLR does not correct hypotension, immediately shift focus to vasopressor or inotropic support rather than continuing fluid administration. 1

Context-Specific Treatment Approaches

Perioperative/Postoperative Hypotension

Symptomatic hypotension should be treated immediately. 1

• For positive PLR test: Administer intravenous fluid 1
• For negative PLR test: Initiate vasopressor or inotropic support 1
• Consider phenylephrine specifically when hypotension is accompanied by tachycardia, as it causes reflex bradycardia (avoid in preload-independent states) 1
• Non-invasive cardiac output monitors and portable ultrasound can help identify the root cause 1
• Transfer to higher level of care may be required for appropriate therapy delivery 1

Trauma-Related Hypotension (Without Brain Injury)

Use a restricted volume replacement strategy with target systolic blood pressure of 80-90 mmHg (mean arterial pressure 50-60 mmHg) until major bleeding is controlled. 1

• This "permissive hypotension" approach decreases mortality compared to aggressive fluid resuscitation in trauma patients without traumatic brain injury 1
• Aggressive resuscitation increases mortality, damage control laparotomy rates, coagulopathy, multiorgan failure, and transfusion requirements 1

Critical exception: In patients with severe traumatic brain injury (GCS ≤8), maintain mean arterial pressure ≥80 mmHg to ensure adequate cerebral perfusion. 1

• Permissive hypotension is contraindicated in TBI and spinal injuries 1
• Exercise caution in elderly patients and those with chronic arterial hypertension 1

Septic Shock Hypotension

Norepinephrine is indicated for blood pressure control in acute hypotensive states including septicemia. 2

• Epinephrine can be used as an adjunct in profound hypotension 2, 3
• High-dose epinephrine infusion may be effective for refractory hypotension 1

Pediatric Considerations

For hypotension in children (including cytokine release syndrome) 1:

• Initial normal saline fluid bolus: 10-20 mL/kg (maximum 1,000 mL) 1
• Avoid additional fluid boluses in patients with cardiac dysfunction or volume overload signs (pulmonary edema) 1
• Consider early colloid solutions due to potential rapid capillary leak development 1
• Consider stress-dose hydrocortisone for vasopressor-resistant hypotension from adrenal insufficiency 1
• Transfer to intensive care should be considered early 1

Pharmacological Agents

Vasopressors

• Phenylephrine: Best for hypotension with tachycardia; causes reflex bradycardia 1
• Norepinephrine: FDA-approved for acute hypotensive states (septicemia, myocardial infarction, spinal anesthesia) 2
• Epinephrine: For profound hypotension and cardiac arrest; can be used when high-dose vasopressors are needed 2, 3

Inotropes

• Dobutamine: For low cardiac output from myocardial dysfunction 1
• Epinephrine: Alternative inotrope for cardiac dysfunction 1, 3

Anticholinergics for Bradycardia

• Atropine or glycopyrronium: First-line for bradycardia-induced hypotension 1
• Epinephrine or isoprenaline: When unresponsive to anticholinergics 1

Monitoring and Adjustments

Blood Pressure Targets

Target blood pressure should account for increased venous outflow pressure and extravascular compartment pressures. 1

• If aiming for organ perfusion pressure of 65 mmHg and compartment pressure is 15 mmHg, maintain mean arterial pressure >80 mmHg 1
• Continuous intraoperative arterial pressure monitoring reduces severity and duration of hypotension compared to intermittent monitoring 1

Common Pitfalls to Avoid

• Do not reflexively give fluids without assessing fluid responsiveness—approximately 50% of hypotensive patients are not hypovolemic 1
• Avoid aggressive fluid resuscitation in trauma without brain injury—it increases mortality 1
• Do not use permissive hypotension in traumatic brain injury—maintain MAP ≥80 mmHg 1
• Avoid phenylephrine in preload-independent states—reflex bradycardia can worsen hypotension 1
• Do not continue fluid boluses in patients with cardiac dysfunction or pulmonary edema—switch to vasopressors/inotropes 1