What is the initial treatment for acute heart failure?

Initial Treatment for Acute Heart Failure

The initial treatment for acute heart failure should include oxygen therapy, intravenous diuretics (furosemide), and vasodilators (in patients with normal to high blood pressure), implemented as early as possible to improve symptoms and prevent organ damage. 1

Immediate Assessment and Stabilization

• Assess cardiopulmonary stability immediately upon patient contact, with continuous monitoring of vital signs including pulse oximetry, blood pressure, respiratory rate, and ECG 1
• Determine the clinical profile based on signs of congestion and peripheral perfusion to guide therapy 1
• Monitor mental status using the AVPU (alert, visual, pain, or unresponsive) assessment as an indicator of hypoperfusion 1

First-Line Treatments

Oxygen Therapy and Ventilatory Support

• Provide oxygen therapy to maintain SpO2 between 94-96%, avoiding hyperoxia 1
• Implement non-invasive ventilation (NIV) early in patients with acute pulmonary edema showing respiratory distress 1
• Use continuous positive airway pressure (CPAP) in the pre-hospital setting as it requires minimal training and equipment 1
• Consider pressure-support positive end-expiratory pressure (PS-PEEP) upon hospital arrival, particularly in patients with acidosis, hypercapnia, or COPD history 1

Diuretic Therapy

• Administer intravenous loop diuretics within the first hour of presentation, as early administration is associated with better outcomes 2
• For new-onset heart failure or patients not on maintenance diuretics: start with furosemide 40 mg IV bolus 3, 4
• For established heart failure or patients on chronic oral diuretic therapy: administer IV bolus at least equivalent to oral dose 3, 4
• Monitor urine output frequently, with bladder catheterization recommended to assess treatment response 3
• Limit total furosemide dose to <100 mg in the first 6 hours and <240 mg during the first 24 hours 3

Vasodilator Therapy

• Administer IV vasodilators (nitroglycerin or isosorbide dinitrate) in patients with SBP >90 mmHg without symptomatic hypotension 1, 5
• Vasodilators improve hemodynamics, reduce blood pressure, and increase coronary flow 6
• Nitroglycerin primarily causes venodilation at lower doses, with arterial dilation at higher doses, which can be beneficial in patients with concomitant ischemia 6
• Monitor blood pressure frequently during vasodilator administration 1

Special Considerations

Medications to Use with Caution

• Opioids (morphine): Routine use is not recommended as they may be associated with higher rates of mechanical ventilation, ICU admission, and death despite relieving dyspnea 1
• Inotropes (dobutamine): Reserve for patients with persistent signs of hypoperfusion despite adequate filling status; not indicated when SBP >90 mmHg 1, 7
• Vasopressors: Consider only in cardiogenic shock; norepinephrine is preferred to increase blood pressure and vital organ perfusion 1

Management Based on Blood Pressure

• High BP (hypertensive AHF): Prioritize vasodilators as initial therapy 1
• Normal BP: Balance diuretics and vasodilators 1
• Low BP (SBP <90 mmHg): Avoid vasodilators and use diuretics cautiously; consider inotropes if signs of hypoperfusion persist 1

Monitoring Response to Treatment

• Assess dyspnea, vital signs, SpO2, heart rate and rhythm, urine output, and peripheral perfusion frequently 1
• After 2 hours, spot urinary sodium should be ≥50-70 mmol/L 4
• After 6 hours, urine output should be ≥100-150 mL/hour 4
• If these targets are not reached, consider doubling the diuretic dose or adding combination therapy 4

Potential Adverse Effects to Monitor

• Hypokalaemia, hyponatraemia, hyperuricaemia from diuretics 3
• Hypovolaemia and dehydration; monitor urine output frequently 3
• Hypotension from vasodilators, especially in patients with already low blood pressure 6
• Tachyphylaxis with nitrates, requiring incremental dosing 6

Combination Therapy for Diuretic Resistance

• Consider adding thiazides (hydrochlorothiazide) or aldosterone antagonists (spironolactone 25-50 mg) to loop diuretics 3
• Acetazolamide (500 mg IV once daily) can be effective, particularly with baseline bicarbonate levels ≥27 mmol/L 4
• Combinations in low doses are often more effective with fewer side effects than higher doses of a single drug 3