Noncardiogenic Pulmonary Edema - Differential Diagnosis Framework
NCPE Pathophysiology:
Noncardiogenic pulmonary edema occurs because of excessive pulmonary capillary permeability. Causes include:
1. Excessive renin-angiotensin-aldosterone system activity,
2. Impaired nitric oxide synthesis,
3. Increased endothelin levels,
4. Excessive circulating catecholamines.
History/Physical/Labs:
• A lack of acute cardiac disease
• Normal or negative fluid balance
• Flat neck veins,
• Absence of peripheral edema
• BNP level <100 pg/ml
EKG:
• Negative for ischemic changes
CXR:
• Pulmonary vascular congestion:
• Patchy or peripheral distribution
• Heart size: Normal
ECHO:
• Normal or small chamber size
• Normal left ventricular function
Pulmonary-Artery Catheterization:
• PCWP < 18 mmHg
Etiology:
• Acute respiratory distress syndrome (ARDS)
• Opioid overdose
• Naloxone use causing non-cardiogenic pulmonary edema
• High altitude pulmonary edema
• Bowel infarction
• Gram negative sepsis
• Salicylate toxicity
• Pulmonary embolism
• Re-expansion pulmonary edema (unilateral pulmonary edema)
• Reperfusion pulmonary edema (unilateral pulmonary edema)
• Transfusion-related acute lung injury (TRALI)
• Aspiration of gastric contents
• Head injury
• Pulmonary HTN
• Airway obstruction (laryngospasm)
• Preeclampsia/eclampsia
• Neurogenic pulmonary edema (Traumatic brain injury, cerebral hemorrhage, seizure activity, especially status epilepticus)
#Noncardiogenic #pulmonary #edema #NCPE #differential #diagnosis #cardiology
Acute Hypoxemia - Differential Diagnosis
• Hyperacute: Aspiration, Flash Pulmonary Edema, Mucous Plugging, Bronchospasm, Pulmonary Embolism, Pneumothorax, Alveolar Hemorrhage
• Hypoventilation: Sedatives, Sleep Apnea, OHS, Neuromuscular, Myxedema Coma, Metabolic Alkalosis
• Shunt:
- Physiologic: ARDS, Diffuse Alveolar Process
- Anatomic: Intracardiac, Pulmonary AVMs
• Focal Alveolar: Pneumonia, Mucous Plugging, Atelectasis, Pulmonary Edema, Alveolar Hemorrhage
• Impaired Diffusion: ILD, pHTN, Advanced COPD
• Dead Space: Pulmonary Embolism, Emphysema, Positive Pressure Vent, pHTN, Shock
• Airway Disease: Asthma, COPD, Bronchiectasis
- Sophia Hayes MD @Sophia_Hayes_MD
#Hypoxemia #hypoxia #Differential #Diagnosis #causes #pulmonary
Hypoxemia / Hypoxia - Rapid Response Management Algorithm
Stridor - Upper airway pathology:
• Anaphylaxis
• Foreign body
• Angioedema
• Subglottic stenosis
• Epiglottitis
• Vocal cord dysfunction
• Extrinsic compression (e.g., hematoma, tumor)
Crackles / ↓ Air Movement - Lower airway pathology:
• Blood: diffuse alveolar hemorrhage
• Pus: pneumonia
• Water: pulmonary edema
• Air: pneumothorax, COPD/asthma
• Pleural disease
• Severe atelectasis
• Lung fibrosis
RR < 12 / shallow breathing - Hypoventilation:
• CNS depression (e.g., opioids, OHS, toxic metabolic encephalopathy, central sleep apnea)
• Neuromuscular disorders (e.g., GBS, MG, ALS)
• ↓ chest wall compliance (e.g., flail chest, kyphoscoliosis)
By Matthew Ho, MD PhD @MatthewHoMD, Clement Lee, MD @ClementLeeMD, Sophia Hayes MD @Sophia_Hayes_MD
#Hypoxemia #Hypoxia #differential #Diagnosis #Management #Algorithm #rapid #pulmonary
Uncommon Causes of Noncardiogenic Pulmonary Edema (NCPE) - Differential Diagnosis Framework
High Altitude Pulmonary Edema:
• Accumulation of plasma and some red blood cells in the lung due to an interruption in the pulmonary blood-gas barrier.
• High-altitude pulmonary edema (HAPE) generally occurs above 2,500 m (8,000 ft) and is uncommon below 3,000 m (10,000 ft)
• Symptoms:
- Nonproductive cough, shortness of breath with exertion, difficulty walking uphill
- Dyspnea at rest will become severe with any type of exertion
- Cough may be productive for pink, frothy sputum, as well as frank blood.
- Lethargic and severely hypoxemic.
• Other common assessment findings associated with HAPE are:
- Tachypnea,
- Low-grade fever (up to 100.4°F [38°C]),
- Tachycardia,
- Inspiratory crackles in the right middle lobe that become bilateral and diffuse
Neurogenic Pulmonary Edema:
• Traumatic brain injury, cerebral hemorrhage, and seizure activity, especially status epilepticus
• Pathophysiology: The shift of fluid from the capillaries to the pulmonary interstitium and alveoli thus increases the permeability of the pulmonary capillaries
• Criteria:
- Bilateral pulmonary opacities,
- Amount of oxygen dissolved in the PaO2/FiO2 ratio < 200 mm Hg,
- Presence of central nervous system injury (with associated increased intracranial pressure),
- Absence of other common causes of acute respiratory failure or ARDS (aspiration, massive blood transfusion, sepsis),
- No evidence of left atrial hypertension
TRALI:
• Sudden onset of hypoxemic respiratory insufficiency shortly after or during the administration of a blood product.
• Symptoms: Hypoxemic respiratory insufficiency, fever, chills, pruritus, urticaria, pulmonary infiltrates on chest radiography, pink frothy airway secretions, hypotension, hypovolemia, cyanosis, tachycardia, and tachypnea
Preeclampsia/Eclampsia Pulmonary Edema:
• Pathophysiology:
- Poor uteroplacental circulation caused by inadequate remodeling of the spiral arteries that happens between weeks 8 and 18 of pregnancy.
- The predominant pathophysiologic finding: maternal vasospasm.
• Signs/Symptoms: Tachycardia, hypertension, dyspnea, tachypnea, hypoxemia, scattered crackles, chest pain, cough
Opioid Overdose:
• Any opioid can cause noncardiogenic pulmonary edema, especially fentanyl mixed with heroin, and methadone overdose.
• Signs/Symptoms:
- Respiratory depression and/or agonal respirations.
- The classic signs of opioid intoxication include depressed mental status, decreased respiratory rate, decreased tidal volume, decreased bowel sounds, and miotic pupils
Pulmonary Embolism:
• Acute pulmonary edema can be caused by a massive PE, as well as multiple smaller emboli.
• Pathophysiology:
- PE can cause noncardiogenic pulmonary edema by decreasing the pulmonary and adjacent pleural systemic circulations, raising hydrostatic pressures in pulmonary and systemic veins, and also decreasing pleural pressure due to airway collapse.
- PE also reduces the exit rates of pleural fluid by rising the systemic venous pressure thus limiting lymphatic drainage. Increasing lymphatic filling can also occur with a PE by diminishing pleural pressure.
#Noncardiogenic #pulmonary #edema #causes #differential #diagnosis #NCPE
Reflex Testing - Causes of Hyporeflexia and Hyperreflexia
Focal Hyporeflexia:
• Radiculopathy, Mononeuropathy, Polyneuropathy, Acute stroke, Acute spinal cord injury
Generalized Hyporeflexia:
• Hypercalcemia, Hypermagnesemia, Hypothyroidism, Deep coma (any cause), Severe polyneuropathy (e.g. Guillain-Barré syndrome)
Focal Hyperreflexia:
• Delayed finding in stroke, Delayed finding in spinal cord injury, Early ALS
Generalized Hyperreflexia:
• Hypocalcemia, Hypomagnesemia, Hyperthyroidism, Serotonin syndrome, Eclampsia, Late ALS
- Dr. Eric Strong @DrEricStrong - Strong Medicine https://www.youtube.com/c/EricsMedicalLectures/
#Hyporeflexia #Hyperreflexia #Testing #Causes #differential #diagnosis #table #neurology
Diffuse consolidation
The most common cause of diffuse consolidation is pulmonary edema due to heart failure.
This is also called cardiogenic edema, to differentiate it from the various causes of non-cardiogenic edema.
The increased heart size is usually what distinguishes between cardiogenic and non-cardiogenic.
Look for other signs of heart failure like redistribution of pulmonary blood flow, Kerley B-lines and pleural fluid.
However some patients, who have an acute cardiac infarction, may still have a normal heart size, while other patients who have a large heart due to a chronic heart disease, may have non-cardiac pulmonary edema due to a superimposed pulmonay infection, ARDS, near-drowning etc. #Diagnosis #Radiology #Pulmonary #CXR #Diffuse #Consolidation #Differential #RadiologyAssistant
