Respiratory Failure Overview

Questions and Answers

What is a defining characteristic of respiratory failure?

Normal levels of carbon dioxide

Increased PaO2 above 60 mmHg

Elevated blood pH

Inadequate gas exchange leading to hypoxia (correct)

Which of the following conditions is NOT a cause of respiratory failure?

Severe asthma

High blood pressure (correct)

Pneumonia

COPD

What symptom is associated with hypoxia during respiratory failure?

Confusion (correct)

Drowsiness

Tremor/flap

Hypertension

Which type of respiratory failure requires controlled oxygen therapy?

Type II respiratory failure Signup and view all the answers

What is a common feature of ventilator masks used in oxygen therapy?

Simple face masks may risk CO2 accumulation. Signup and view all the answers

Which finding would indicate hypercapnia in a patient?

Peripheral vasodilatation Signup and view all the answers

What is the primary aim of investigations in respiratory failure?

To identify the underlying cause of the condition Signup and view all the answers

In managing Type I respiratory failure, what therapeutic approach should be prioritized?

Oxygen therapy to correct hypoxia Signup and view all the answers

Study Notes

Definition of Respiratory Failure

Respiratory failure is characterized by inadequate gas exchange, leading to hypoxia (PaO2 < 60 mmHg).
Causes include alveolar hypoventilation and potential ventilation/perfusion (V/Q) mismatch.

Causes of Respiratory Failure

Pulmonary Diseases:
- Severe asthma
- Chronic obstructive pulmonary disease (COPD)
- Pneumonia
- End-stage pulmonary fibrosis
- Obstructive sleep apnea
Reduced Respiratory Drive:
- Sedative drugs
- CNS tumors
- Trauma
Neuromuscular Diseases:
- Cervical cord lesions
- Diaphragmatic paralysis
- Poliomyelitis
- Myasthenia gravis
- Guillain–Barré syndrome
Thoracic Wall Diseases:
- Flail chest
- Kyphoscoliosis

Clinical Features

Symptoms of hypoxia include:
- Dyspnea
- Restlessness
- Agitation
- Confusion
- Central cyanosis
Long-term hypoxia can lead to:
- Polycythemia
- Pulmonary hypertension
- Cor pulmonale
Symptoms of hypercapnia include:
- Headache
- Peripheral vasodilation
- Tachycardia
- Bounding pulse
- Tremor/flap
- Papilledema
- Confusion
- Drowsiness
- Coma

Investigations

Blood tests: Full blood count (FBC), urea & electrolytes (U&E), C-reactive protein (CRP), arterial blood gases (ABG).
Radiology: Chest X-ray (CXR).
Microbiology: Sputum and blood cultures if febrile.

Management Strategies

Type I Respiratory Failure:
- Treat the underlying cause.
- Administer oxygen via facemask to alleviate hypoxia.
- Consider assisted ventilation as needed.
Type II Respiratory Failure:
- Address the underlying cause.
- Utilize controlled oxygen therapy.
- Employ assisted ventilation, with intubation considered if other treatments fail.
- Oxygen delivery methods include:
  - Nasal Cannulae: Well-accepted by patients; offers imprecise O2 delivery and potential nasal soreness.
  - Simple Face Mask: Varies O2 delivery based on inflow rate; risk of CO2 accumulation.
  - Venturi Mask: Provides controlled FiO2 at high flow rates; start at 24-28% for COPD patients.
  - Non-rebreathing Mask: Equipped with a reservoir bag; capable of delivering high O2 concentrations (60-90%).
  - Non-invasive Ventilation: Such as CPAP/BiPAP.
  - Invasive Ventilation: Considered in severe cases.

Description

This quiz covers the critical topic of respiratory failure, defined by inadequate gas exchange leading to hypoxia. Key causes of respiratory failure such as pulmonary diseases, reduced respiratory drive, and neuromuscular diseases are emphasized. Test your understanding of the underlying mechanisms and conditions associated with this medical emergency.