Respiratory failure management

Respiratory failure management

Respiratory failure is a clinical condition that occurs when the respiratory system fails to maintain its primary function of gas exchange, resulting in:

• PaO₂ less than 60 mmHg and/or

• PaCO₂ greater than 50 mmHg

Respiratory failure is classified according to arterial blood gas abnormalities into Type I (hypoxemic) and Type II (hypercapnic) respiratory failure.

Classification

Type I respiratory failure (hypoxemic respiratory failure)

Type I respiratory failure is characterized by:

• PaO₂ less than 60 mmHg

• Normal or reduced PaCO₂

In this type, gas exchange is impaired at the alveolar-capillary membrane.

Examples include:

• Cardiogenic pulmonary oedema

• Non-cardiogenic pulmonary oedema

• Severe pneumonia

Type II respiratory failure (hypercapnic respiratory failure)

Type II respiratory failure is characterized by:

• PaCO₂ greater than 50 mmHg

Hypoxaemia is common and occurs due to respiratory pump failure.

Investigations

Arterial blood gas analysis

• Arterial blood gas (ABG)

Haematological investigations

• Full blood picture (FBP)

Cardiac investigations

• Electrocardiography (ECG)

• Echocardiography (ECHO)

• Troponin-I

• Creatine kinase

Endocrine investigations

• Thyroid-stimulating hormone (TSH)

Respiratory investigations

• Chest X-ray (CXR)

• Pulmonary function tests (PFTs), if the patient is able to perform them

Biochemical investigations

• Electrolytes

• Creatinine

• Blood urea nitrogen (BUN)

• AST

• ALT

• ALP

• GGT

• Albumin

• Total bilirubin

• Direct bilirubin

Non-pharmacological treatment

Non-invasive ventilatory support

• Recommended for patients with mild-to-moderate acute respiratory failure.

Mechanical ventilation

• Mechanical ventilation may be required in severe respiratory failure.