What is the treatment for hypotension?

Treatment for Hypotension

Hypotension treatment must be immediately directed at the underlying physiological cause—vasodilation, hypovolaemia, bradycardia, or low cardiac output—rather than empirically administering fluids, as only approximately 50% of hypotensive patients are fluid-responsive. 1, 2

Algorithmic Approach to Cause-Directed Treatment

The most critical first step is determining which physiological derangement is causing hypotension, as treatment differs fundamentally based on etiology 3, 1, 2:

For Vasodilation

• Administer vasopressors 1, 2
• Norepinephrine is the first-line vasopressor for vasodilation-induced hypotension 2, 4
• Phenylephrine is best for hypotension with tachycardia, as it causes reflex bradycardia 1

For Hypovolaemia

• Perform a passive leg raise (PLR) test BEFORE administering fluids to determine fluid responsiveness 1, 2
• 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; pooled sensitivity 88%) 1
• If PLR positive, administer intravascular fluids: crystalloid, colloid, or blood products 1, 2
• Initial fluid bolus: 250-500 mL in adults; 10-20 mL/kg (maximum 1,000 mL) in children 1, 2

For Bradycardia

• Atropine or glycopyrronium as first-line treatment 1, 2
• If refractory, use epinephrine or isoprenaline 1
• Consider pacing for profound bradycardia 1

For Low Cardiac Output

• Dobutamine is recommended for low cardiac output from myocardial dysfunction 1, 2
• Epinephrine is an alternative for myocardial dysfunction 1, 2, 5

Context-Specific Modifications

Trauma Without Brain Injury

• Use 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

Elevated Compartment or Venous Pressures

• Increase MAP target by roughly the compartment pressure 1, 2
• Target blood pressure should account for increased venous outflow pressure and extravascular compartment pressures 1

Perioperative Setting

• Maintain intraoperative MAP ≥60 mm Hg in at-risk patients, as MAP <60-70 mm Hg or systolic BP <90-100 mm Hg are associated with acute kidney injury, myocardial injury, myocardial infarction, and death 3

Pediatric Patients

• 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

Monitoring Recommendations

• Continuous arterial pressure monitoring reduces severity and duration of hypotension compared to intermittent monitoring 3, 1, 2
• Administer vasoactive agents targeted to effect rather than fixed doses 2
• Postoperative hypotension is often unrecognized and may be more important than intraoperative hypotension because it is often prolonged and untreated 3

Critical Pitfalls to Avoid

• Do NOT reflexively give fluids without assessing fluid responsiveness—approximately 50% of hypotensive patients are not hypovolemic and require correction of vascular tone or inotropy instead 1, 2
• Do NOT use aggressive fluid resuscitation in trauma without brain injury—it increases mortality 1, 2
• Do NOT use permissive hypotension in traumatic brain injury—maintain MAP ≥80 mmHg 1, 2
• When treating intraoperative hypertension, do so carefully to avoid hypotension 3