Pulmonary edema
Background
- Cardiogenic vs Non-Cardiogenic (ARDS/Altitude/Neurogenic)
- Mechanism of Cardiogenic
- Failing heart > pulm edema > stress response > incr afterload
- Incr afterload > incr pulm edema
- Failing heart > pulm edema > stress response > incr afterload
- Pts often intravascularly depleted; avoid diuretics!
Causes
- Cardiogenic
- Non-cardiogenic
- Hypertensive crisis.
- Negative pressure pulmonary edema (Upper airway obstruction)
- Neurogenic causes
- Other
- ARDS
- Inhalation of hot or toxic gases
- Pulmonary contusion
- Aspiration
- Reexpansion edema (post large volume thoracocentesis, resolution of pneumothorax, post decortication, removal of endobronchial obstruction, effectively a form of negative pressure pulmonary oedema.
Reperfusion injury, i.e. postpulmonary thromboendartectomy or lung transplantation Immersion pulmonary edema[7][8] Multiple blood transfusions Severe infection or inflammation which may be local or systemic. This is the classical form of ALI-ARDS. There are also a range of causes of pulmonary edema which are less well characterised and arguably represent specific instances of the broader classifications above.
Arteriovenous malformation Hantavirus pulmonary syndrome High altitude pulmonary edema (HAPE), probably a manifestation of neurogenic pulmonary edema[9][10] Envenomation, such as with the venom of Atrax robustus[11] Flash pulmonary edema Swimming induced pulmonary edema
Diagnosis
- Crackles
- Respiratory distress
Differential Diagnosis
Acute dyspnea
Emergent
- Pulmonary
- Airway obstruction
- Anaphylaxis
- Angioedema
- Aspiration
- Asthma
- Cor pulmonale
- Inhalation exposure
- Noncardiogenic pulmonary edema
- Pneumonia
- Pneumocystis Pneumonia (PCP)
- Pulmonary embolism
- Pulmonary hypertension
- Tension pneumothorax
- Idiopathic pulmonary fibrosis acute exacerbation
- Cystic fibrosis exacerbation
- Cardiac
- Other Associated with Normal/↑ Respiratory Effort
- Other Associated with ↓ Respiratory Effort
Non-Emergent
- ALS
- Ascites
- Uncorrected ASD
- Congenital heart disease
- COPD exacerbation
- Fever
- Hyperventilation
- Interstitial lung disease
- Neoplasm
- Obesity
- Panic attack
- Pleural effusion
- Polymyositis
- Porphyria
- Pregnancy
- Rib fracture
- Spontaneous pneumothorax
- Thyroid Disease
- URI
Treatment
- CPAP/BiPAP with PEEP 6-8; titrate up to PEEP of 10-12
- Nitroglycerin
- Dosing Options
- Sublingual 0.4 mg q5min
- Nitropaste (better bioavailability than oral Nitroglycerin)
- Intravenous: 0.1mcg/kg/min - 5mcg/kg/min
- Dosing Options
Generally start IV Nitroglycerin 50mcg/min and titrate rapidly (150mcg/min or higher)to symptom relief
- If NTG fails to reduce BP consider nitroprusside (reduces both preload and afterload) or ACE-inhibitiors (preload reducer)
- After pt improves titrate down NTG as enaliprilat (0.625 - 1.25mg IV) or captopril are started
- Morphine is no longer recommended do to increased morbidity