Causes of type I respiratory failure include all of the following except?

9 e. Respiratory failure is a syndrome in which the respiratory system fails in one or both of its gas exchange functions: oxygenation and carbon dioxide elimination. Respiratory failure may be classified as hypoxaemic or hypercapnic and may be either acute or chronic.

Hypoxaemic respiratory failure (type I) is characterised by a low PaO2 with a normal or low PaCO2. This is the most common form of respiratory failure, and it can be associated with virtually all acute diseases of the lung, which generally involve fluid filling or collapse of alveolar units. Some examples of type I respiratory failure are cardiogenic or non-cardiogenic pulmonary oedema, pneumonia, acute pulmonary embolus and acute exacerbation of asthma.

Hypercapnic respiratory failure (type II) is characterised by a low PaO2 and a high PaCO2. The pH depends on the level of bicarbonate, which, in turn, is dependent on the duration of hypercapnia. Common causes include drug overdose, neuromuscular disease, chest wall abnormalities and severe airway disorders (e.g. asthma, chronic obstructive pulmonary disease (COPD) and chronic pulmonary emboli).