Acute Respiratory Failure Flashcards
What is Acute Respiratory Failure?
Impairment in Gas Exchange
Not a disease but a symptom
Hypoxemic ARF:
PaO2<60 on 60% O2
Hypercapnic ARF:
PaCO2>45
pH<7.35
Hypoxemic/Oxygenation Failure is? and examples?
V/Q mismatch, Shunting, Impaired diffusion • Pneumonia • Pulmonary Embolism • Pulmonary Edema • ARDS
Hypercapnic/Ventilatory Failure is? and examples?
Impaired ventilation, Impaired chest wall movement • Asthma • COPD • Pain • Drug overdose • Neurological disorders – MG – GB – MS
Failure of Oxygenation
Hypoxemic Failure
Ventilation-perfusion mismatch (V/Q mismatch) – Intrapulmonary shunting – Increased dead space ventilation • Diffusion defects • Low cardiac output • Low hemoglobin level
Anatomic Shunt:
Blood passes through an
anatomic channel in the
heart bypassing the lungs.
Ventricular septal defect
Physiologic Shunt:
Blood flows through the
pulmonary capillaries
without participating in
gas exchange….(Low V/Q)
Pneumonia
ARDS
Diffusion Limitations
Thickened alveolar/capillary
membrane impairs gas exchange …
Greater distance CO2 and O2 have to travel.
Failure of Ventilation
Hypercapnic Failure
Alveolar hypoventilation
- Respiratory muscle fatigue
- CNS depressants
- Head injury
- Chest wall abnormalities
- Neuromuscular conditions
Hypoxemia Manifestations
- Tachycardic/Tachypneic
- Increased BP
- Restless
- Confusion
- Anxiety
Hypercapnia Manifestations
- Tachycardic/Tachypneic
- Headache
- Decreased LOC
- Increased somnolence
- Dizzy
- Flushed
ARF Manifestations:
•Pursed-lip breathing • Retractions • Orthopnea • Tripod position – increases AP diameter – decreases work of breathing • Inability to speak in full sentences
Diagnosis
• History • Chest x-ray • Blood work – Arterial blood gases – SvO2 – H & H – Sputum cultures • Pulse oximetry
Medical Management
- Oxygen/Respiratory Management
- Bronchodilators
- Corticosteroids
- Diuretics
- Hydration
- Nutrition
- Treatment of underlying cause