ECG to evaluate for cardiac ischemia and dysrhythmias.
Chest x-ray to confirm the diagnosis and assessing illness severity.
Labs: B-type natriuretic peptide (BNP), cardiac enzymes, and creatinine
DIAGNOSIS TESTS & NTERPRETATION Lab
BNP:
Lab parameter for the detection and follow-up of heart failure:
<100 pg/mL: CHF unlikely
100–500 pg/mL: Indeterminate
>500 pg/mL: Most consistent with CHF
May not be elevated in very acute CHF or ventricular inflow obstruction
May be falsely elevated in patients with renal failure undergoing dialysis due to LVH
N-terminal pro-BNP:
Similar test characteristics to BNP
Cardiac troponins:
May be elevated due to myocardial ischemia causing AHF or as result of AHF’s effects on cardiac myocytes
Elevated in 20% of AHF episodes
Strong negative prognostic factor
Serum chemistry panel:
Creatinine elevation:
Predicts all-cause mortality in chronic heart failure
Indication of acute end-organ hypoperfusion
Indication for admission or observation
Hyponatremia: Marker of severe HF
Electrolyte abnormalities are common due to various HF treatments.
Elevated alanine aminotransferase, aspartate aminotransferase, or bilirubin suggests congestive hepatopathy.
Serum lipase if pancreatitis is suspected as the underlying cause
Arterial blood gas: Evaluates hypoxemia, ventilation/perfusion mismatch, hypercapnia, and acidosis.
Imaging
CXR:
Pulmonary redistribution: Cephalization of vessels
Cardiomegaly: Cardiac silhouette >50% of thoracic width on PA exam only
Interstitial edema:
Pleural effusions
Kerley B lines
Bilateral perihilar alveolar edema producing a characteristic butterfly pattern
Noncardiogenic: Bilateral interstitial or alveolar infiltrates in a homogeneous pattern, typically without enlarged heart shadow
Radiographs are often normal in the 1st 12 hr of the disease process.
ECG:
Assess for underlying cardiac disorders:
Acute dysrhythmias
Signs of acute coronary syndromes
Signs of electrolyte abnormalities
Atrial fibrillation occurs in 30–42% of patients admitted for acute heart failure.
Both tachy- and bradydysrhythmias can lead to decreased cardiac output.
Echocardiography:
Evaluates left ventricle function
Assesses acute valvular or pericardial pathology
Measures cardiac output
Bedside ultrasonography:
Bilateral B-lines: Comet-tail artifacts arising from pleural line extending to the far field without a decrease in intensity on both the left and the right thorax
DIFFERENTIAL DIAGNOSIS
COPD exacerbation
Pneumonia
Asthma
Pulmonary embolism
Pericardial tamponade
Pneumothorax
Pleural effusion
Anaphylaxis
Acidosis
Hyperventilation syndrome
TREATMENT PRE HOSPITAL
IV access
Supplemental oxygen
100% nonrebreather mask
Cardiac monitor
Pulse oximetry
Sublingual nitrates
If bag valve mask is needed, should use PEEP valve if available
Endotracheal intubation in severe cases.
INITIAL STABILIZATION/THERAPY
Assess and gain control of airway, breathing, and circulation.
Noninvasive ventilation or endotracheal intubation for impending respiratory failure.
IV access
Supplemental oxygen
Cardiac monitor
Pulse oximetry
Place patient in an upright position.
Inotropic therapy for hypotensive patient with signs of end-organ dysfunction
ED TREATMENT/PROCEDURES
Treatment decisions should be based on the underlying cause of pulmonary edema.
Supplemental O 2
Volume restriction
Urine output monitoring with or without urinary catheter
BiPAP/CPAP:
Improves oxygenation, reduces respiratory work, decreases left ventricular afterload
Reduces need for intubation, length of stay, and mortality
Positive-end expiratory pressure: Most useful strategy for oxygenation
Hypotensive patients:
Avoid nitrates, angiotensin-converting enzyme inhibitors (ACEIs), and morphine.
Initiate inotropes:
Dobutamine, Dopamine, Norepinephrine, or Milrinone
Direct cardioversion for new onset unstable atrial fibrillation
Normotensive or hypertensive patients:
Nitrates (nitroglycerin vs. nitroprusside)
Diuretics (furosemide vs. bumetanide) may be most effective after initial stabilization
Noncardiogenic: Treat underlying cause.
MEDICATION
Aspirin: 325 mg PO/PR if myocardial infarction suspected
Bumetanide: 1–3 mg IV
Captopril: 6.25 mg SL
Dobutamine: 2–10 μg/kg/min IV, titrate. May lower BP due to vasodilatory effects.
Dopamine: 2 × 20 μg/kg/min IV; titrate
Enalapril: 0.625–1.25 mg IV
Furosemide: 20–80 mg IV
Torsemide: 10–20 mg IV
Milrinone: 50 μg/kg IV; titrate; inotropic effects comparable to dobutamine
Nitroglycerin: 0.4 mg SL; 1–2 in; 5–20 μg/min IV and titrate; Nitropaste is not preferred as it is more difficult to titrate and to use in diaphoretic patients.
Nitroprusside: 0.25–0.3 μg/kg/min, titrate up by 0.5 μg/kg/min q2–3 min until desired effect
Norepinephrine: 2–12 μg/min IV; titrate
FOLLOW-UP DISPOSITION Admission Criteria
ICU:
Positive-pressure ventilation
Inotropic support
Acute cardiac ischemia or infarction
ARDS
Monitored unit:
New-onset pulmonary edema
Electrocardiographic changes
Patients presenting with risk factors for mortality, including advanced age, renal dysfunction, hypotension, digoxin use, and anemia
Discharge Criteria
Most patients with pulmonary edema should be admitted or observed for 24 hr.
Patients with mild underlying disease and a mild exacerbation that responds fully to ED management and have no risk factors for in-house mortality (see above) may be discharged.
Ensure close outpatient follow-up.
FOLLOW-UP RECOMMENDATIONS
Contact patient’s primary physician and/or cardiologist to establish close follow-up.
Continue diuresis.
Low-salt diet
Daily weights
PEARLS AND PITFALLS
Nitrates, SL and IV, are 1st-line therapy to reduce preload.
BNP can reliably differentiate between AHF syndromes and other causes of dyspnea.
AHF chest radiography findings can be absent early in disease course.
Aggressive, early treatment of normotensive and hypertensive patients with nitrates, diuretics, and ACEIs can rapidly reverse the clinical course.
Positive-pressure ventilation is an essential intervention in noncardiogenic pulmonary edema and can reduce rates of intubation and mortality in AHF.
ADDITIONAL READING
Heart Failure Society of America, LindenfeldJ, Albert NM, et al. HFSA2010 Comprehensive Heart Failure Practice Guideline. J Card Fail. 2010;16(6):e1–e194.
Jois-Bilowich P, Diercks D. Emergency department stabilization of heart failure. Heart Fail Clin. 2009;5(1):37–42.
Wang CS, FitzGerald M, Schulzer M. Does this dyspneic patient in the emergency department have congestive heart failure? JAMA . 2005;294:1944–1956.
Ware LB, MatthayMA. Clinical practice. Acute pulmonary edema. N Engl JMed .2005;353:2788–2796.
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