What is the approach to managing acute heart failure?

Approach to Acute Heart Failure

Initiate immediate stabilization with IV loop diuretics and non-invasive ventilation for respiratory distress, prioritizing rapid decongestion within the first 60 minutes of presentation. 1

Immediate Assessment and Triage (First 5-10 Minutes)

Determine cardiopulmonary stability by evaluating two critical domains:

• Respiratory distress indicators: respiratory rate >25/min, SpO₂ <90% despite oxygen, increased work of breathing, or use of accessory muscles 2, 1
• Hemodynamic instability indicators: heart rate <40 or >130 bpm, systolic blood pressure <90 mmHg or >180 mmHg, severe arrhythmias, or signs of hypoperfusion (oliguria, cold peripheries, altered mental status) 2

Position the patient upright immediately to reduce work of breathing and improve ventilation 1

Establish continuous monitoring within minutes: pulse oximetry, blood pressure, respiratory rate, continuous ECG 2, 1

Triage patients with persistent dyspnea or hemodynamic instability to resuscitation area/CCU/ICU for emergency interventions 2, 1

Initial Diagnostic Workup (Concurrent with Treatment)

Obtain ECG immediately to exclude ST-elevation myocardial infarction and identify arrhythmias requiring urgent intervention 1, 3

Measure plasma natriuretic peptides (BNP/NT-proBNP) to confirm diagnosis 1, 3

Order essential laboratory tests: troponin, complete blood count, renal function (BUN, creatinine), electrolytes, arterial blood gases if severe respiratory distress 2, 1

Obtain chest X-ray to assess pulmonary congestion and exclude alternative causes of dyspnea 1

Perform transthoracic echocardiography to assess cardiac function, valvular abnormalities, and guide management 2

Respiratory Support

Administer oxygen therapy only when SpO₂ <90%—avoid hyperoxia as it may be harmful 1, 3

Initiate non-invasive ventilation (NIV) immediately in patients with acute pulmonary edema showing respiratory distress, as this reduces intubation rates and may reduce mortality 2, 1, 3

• Use CPAP in the prehospital setting because it is simpler than pressure support ventilation, requires minimal training, and does not require a ventilator 2, 1, 3
• Switch to PS-PEEP in hospital if acidosis and hypercapnia persist, particularly in patients with COPD history or signs of fatigue 2, 1

Intubate if NIV fails or if patient has severe hypoxemia unresponsive to NIV, worsening acidosis, or altered mental status 2

Pharmacological Management: Blood Pressure-Guided Algorithm

For Systolic Blood Pressure >110 mmHg (Hypertensive AHF)

Initiate aggressive blood pressure reduction with IV vasodilators in combination with loop diuretics 1

• IV nitroglycerin: starting dose 0.3-0.5 µg/kg/min, titrate upward every 5-10 minutes based on blood pressure response 2, 4
• Sodium nitroprusside: starting dose 0.1 µg/kg/min for patients not responding to nitrates or those with severe mitral/aortic regurgitation or marked hypertension 2
• Titrate vasodilators to systolic blood pressure 85-90 mmHg as lower limit, ensuring adequate organ perfusion 2

Add IV loop diuretics: furosemide 40 mg IV for new-onset heart failure or patients not on maintenance diuretics; for patients on chronic oral diuretics, give IV bolus at least equivalent to oral dose (typically double the home dose) 2, 1, 3, 5

For Systolic Blood Pressure 90-110 mmHg (Normotensive AHF)

IV loop diuretics are first-line therapy 2, 1, 3

• Furosemide 40 mg IV for new-onset heart failure or no maintenance diuretic 2, 1, 3
• IV bolus at least equivalent to oral dose (typically double the home dose) for established heart failure on chronic oral diuretics 2, 1, 3
• Door-to-diuretic time should not exceed 60 minutes 5

For Systolic Blood Pressure <90 mmHg (Cardiogenic Shock)

Rapid IV fluid bolus initially (unless obvious volume overload) and observe response 2

If unresponsive to fluids or volume overload present, initiate IV dopamine 2

Insert pulmonary artery catheter in all patients with cardiogenic shock unless rapid response to fluid administration 2

Consider intraaortic balloon counterpulsation for hemodynamic stabilization while awaiting definitive intervention 2

Milrinone may be considered for short-term IV treatment in acute decompensated heart failure with close cardiac monitoring 6

Monitoring Diuretic Response (Critical First 6 Hours)

After 2 hours: measure spot urinary sodium—target ≥50-70 mmol/L 5, 7

After 6 hours: assess urine output—target ≥100-150 mL/hour 5, 7

If targets not met, double the original loop diuretic dose to maximum of 400-600 mg furosemide per day (up to 1000 mg in severe renal impairment) 5

Continuous infusion offers no benefit over intermittent boluses (DOSE trial) 5

Sequential Diuretic Escalation for Inadequate Response

If congestion persists after 24-48 hours of maximized loop diuretic therapy, add combination diuretic therapy: 5, 7

• Acetazolamide 500 mg IV once daily (particularly useful if baseline bicarbonate ≥27 mmol/L; remains effective with renal dysfunction; use only first 3 days to prevent metabolic disturbances) 5, 7
• OR hydrochlorothiazide as alternative thiazide-type diuretic 2, 5
• OR spironolactone for additional diuresis 2

Management of Specific Precipitants

For acute coronary syndrome: implement immediate invasive strategy with intent to perform revascularization; consider thrombolysis if cardiac catheterization cannot be done expeditiously 2, 1, 3

For rapid arrhythmias: correct urgently with medical therapy or electrical cardioversion 1, 3

For heart failure with atrial fibrillation: consider IV cardiac glycosides for rapid ventricular rate control, though beta-blockers are preferred first-line treatment for rate control in stable patients 2, 1, 3

For significant mitral regurgitation or ventricular septal rupture: obtain hemodynamic stabilization for definitive diagnostic studies or intervention 2

In-Hospital Monitoring

Daily weights and accurate fluid balance charts 2, 1

Daily renal function and electrolytes (urea, creatinine, potassium, sodium) 2, 1

Standard non-invasive monitoring: pulse, respiratory rate, blood pressure continuously 2, 1

Measure natriuretic peptides before discharge to help with post-discharge planning—patients whose levels fall during admission have lower mortality and readmission rates at 6 months 2

Pulmonary artery catheter is NOT routinely indicated except in cardiogenic shock or patients not responding to therapy where cardiac vs. noncardiac pulmonary edema is unclear 2

Common Pitfalls to Avoid

Do NOT routinely use morphine—associated with higher rates of mechanical ventilation, ICU admission, and death in ADHERE registry 2

Do NOT use vasodilators if systolic blood pressure <110 mmHg 2

Avoid hyperoxia—administer oxygen only when SpO₂ <90% 1, 3

Do NOT discharge patients with residual congestion—associated with poor prognosis 5

Avoid delaying diuretic administration—door-to-diuretic time should not exceed 60 minutes 5

Discharge Criteria

Patients are medically fit for discharge when: 2, 1, 3

• Hemodynamically stable and euvolemic for at least 24 hours
• Established on evidence-based oral medication (guideline-directed medical therapy)
• Stable renal function for at least 24 hours before discharge
• Provided with tailored education and advice about self-care

Post-Discharge Follow-Up

Enroll in disease management programs 2

See general practitioner within 1 week of discharge 2, 3

See hospital cardiology team within 2 weeks of discharge 2, 3

Follow-up within multi-professional heart failure service for continuation and up-titration of disease-modifying therapy 2

Focus on up-titrating treatments to recommended doses within 2 weeks (STRONG-HF trial) 5