What is the initial workup and management for hypotension in adults?

Initial Workup and Management of Hypotension in Adults

The initial workup for hypotension in adults requires immediate assessment of hemodynamic stability, rapid identification of the underlying cause through targeted history, physical examination, and basic laboratory tests, followed by cause-specific treatment—with vasopressor support (epinephrine or vasopressin) initiated promptly in shock states while the diagnostic evaluation proceeds. 1

Immediate Assessment and Stabilization

Vital Signs and Hemodynamic Status

• Measure blood pressure in both supine and standing positions (after 5 minutes of rest, then at 1 and 3 minutes after standing) to identify orthostatic hypotension, defined as a drop ≥20 mmHg systolic or ≥10 mmHg diastolic 2, 3
• Assess heart rate, respiratory rate, oxygen saturation, and mental status to determine severity and need for immediate intervention 1
• Evaluate for signs of shock: altered mental status, cool/clammy skin, delayed capillary refill, oliguria 1

Immediate Interventions for Shock States

• For vasodilatory shock (particularly septic shock), initiate epinephrine infusion at 0.05-2 mcg/kg/min titrated to achieve adequate mean arterial pressure, with adjustments every 10-15 minutes 4
• Vasopressin is indicated to increase blood pressure in adults with vasodilatory shock who remain hypotensive despite fluids and catecholamines 5
• Administer IV fluids (crystalloids) for suspected hypovolemia while diagnostic workup proceeds 1

Diagnostic Workup

Targeted History

• Medication review: Identify antihypertensives, diuretics, vasodilators, psychotropic medications, alcohol use, and recent medication changes 2, 6
• Symptom characterization: Determine if hypotension is postural, postprandial, or persistent; assess for associated symptoms (dizziness, syncope, chest pain, dyspnea, abdominal pain) 6, 7
• Underlying conditions: Screen for diabetes (autonomic neuropathy), heart failure, renal disease, neurological disorders, recent infections, or bleeding 6, 8
• Timing and triggers: Identify precipitants such as cough, micturition, carotid sinus pressure (suggesting parasympathetic activation), or meals (postprandial hypotension) 6

Physical Examination Findings

• Cardiovascular: Assess jugular venous pressure (low in hypovolemia, elevated in cardiogenic shock), heart sounds (murmurs suggesting valvular disease, muffled sounds in tamponade), peripheral pulses 1
• Volume status: Check for dry mucous membranes, poor skin turgor (hypovolemia), or edema (heart failure) 1
• Neurological: Evaluate for autonomic dysfunction signs—anhidrosis, fixed pupils, bladder dysfunction—suggesting central (Shy-Drager syndrome) or peripheral (Bradbury-Eggleston syndrome) autonomic impairment 6
• Abdominal: Palpate for tenderness, masses, or pulsatile mass (ruptured AAA); assess for peritoneal signs 1
• Skin: Look for signs of infection, rash (suggesting sepsis or adrenal insufficiency), or café-au-lait spots (pheochromocytoma with neurofibromatosis) 2

Essential Laboratory Tests

• Complete blood count: Identify anemia (bleeding) or leukocytosis (infection) 1
• Basic metabolic panel: Assess for hyponatremia and hyperkalemia (adrenal insufficiency), renal dysfunction, or electrolyte abnormalities 2, 1
• Lactate: Elevated in shock states, guides resuscitation adequacy 1
• Troponin: Rule out acute coronary syndrome in appropriate clinical context 1
• Blood cultures: Obtain before antibiotics if sepsis suspected 1

Additional Diagnostic Studies Based on Clinical Suspicion

• ECG: Identify arrhythmias, acute MI, or pericarditis 1
• Bedside ultrasound: Assess cardiac function, pericardial effusion, volume status (IVC collapsibility), intra-abdominal free fluid 1
• Chest X-ray: Evaluate for pneumonia, pulmonary edema, pneumothorax 1
• Plasma aldosterone/renin ratio: Screen for primary aldosteronism in resistant hypotension with hypokalemia (after correcting potassium and withdrawing aldosterone antagonists for 4-6 weeks) 2
• 24-hour urinary fractionated metanephrines or plasma metanephrines: Evaluate for pheochromocytoma if paroxysmal hypertension/hypotension with "spells" 2

Cause-Specific Management

Orthostatic Hypotension (Neurogenic)

• Non-pharmacologic interventions first: Increase fluid intake (2-2.5 L/day), increase salt intake (6-10 g/day), wear compression stockings, elevate head of bed 10-30 degrees, avoid prolonged standing, rise slowly from supine position 3, 7, 8
• For patients with supine hypertension and orthostatic hypotension, switch BP-lowering medications that worsen orthostatic hypotension to alternative therapies rather than simply reducing dosage 2, 3
• Droxidopa is FDA-approved for neurogenic orthostatic hypotension when non-pharmacologic measures fail 3
• Consider fludrocortisone or midodrine as additional pharmacologic options for refractory cases 7, 8

Medication-Induced Hypotension

• Discontinue or reduce offending agents: Antihypertensives, diuretics, alpha-blockers, vasodilators, tricyclic antidepressants 2, 6
• Reassess blood pressure goals, particularly in elderly patients where asymptomatic orthostatic hypotension should not automatically trigger medication down-titration 2

Hypovolemic Hypotension

• Administer IV crystalloids (normal saline or lactated Ringer's) with serial reassessment 1
• Identify and control bleeding source if hemorrhagic shock 1
• Transfuse blood products as indicated for significant anemia 1

Septic Shock

• Initiate broad-spectrum antibiotics within 1 hour of recognition 1
• Source control (drain abscesses, remove infected devices) 1
• Epinephrine 0.05-2 mcg/kg/min or vasopressin as vasopressor support 4, 5

Cardiogenic Shock

• Identify and treat underlying cause (acute MI, arrhythmia, valvular emergency, tamponade) 1
• Consider inotropic support and urgent cardiology consultation 1

Endocrine Causes

• Adrenal insufficiency: Administer hydrocortisone 100 mg IV immediately if suspected (do not delay for confirmatory testing) 1
• Hypothyroidism: Initiate thyroid hormone replacement cautiously, as rapid correction can precipitate cardiovascular events 2

Common Pitfalls to Avoid

• Do not assume hypotension is benign in elderly patients—it may represent serious underlying pathology requiring urgent intervention 1
• Do not automatically reduce antihypertensive medications in patients with asymptomatic orthostatic hypotension, as intensive BP control reduces orthostatic hypotension risk and does not increase falls or syncope 2
• Do not delay vasopressor initiation in shock states while awaiting complete diagnostic workup—early hemodynamic support improves outcomes 4, 5
• Do not overlook medication-induced hypotension, particularly in patients on multiple antihypertensives, diuretics, or psychotropic medications 2, 6
• Do not miss adrenal insufficiency—maintain high index of suspicion in patients with hypotension, hyponatremia, and hyperkalemia 2

Serial Reassessment

• Reassess vital signs, mental status, and urine output every 15-30 minutes during acute resuscitation 1
• Adjust vasopressor doses incrementally (every 10-15 minutes) to achieve target MAP, then wean gradually over 12-24 hours after hemodynamic stabilization 4
• Monitor for complications of hypotension: acute kidney injury, myocardial ischemia, mesenteric ischemia, stroke 1, 8