The Respiratory System

The following management options are available:

Oxygen

Oxygen should be administered guided by alert cards (if carried). Otherwise aim for an oxygen saturation (SpO₂) of 88-92% with a 28% Venturi mask pending ABG measurement. Increase the flow rate by 50% if the RR >30/min [20].The SpO₂ can be adjusted to 94-98% if the pCO₂ is normal. ABG assay should be rechecked after 30-60 mins.

Non-invasive ventilation

Non-invasive ventilation may be helpful in patients with acute Type II respiratory failure or acute on chronic respiratory failure in the short term. The evidence for any benefit however is inconclusive [21], and the decision to commence NIV should be discussed with the CF team wherever possible. Clearly, patients with massive haemoptysis or pneumothorax should not have NIV instituted. Ventilation with endotracheal intubation is associated with poor outcome when used as an emergency [13].

Antibiotics

Antibiotic treatment for respiratory exacerbations (including moderate or severe haemoptysis) should be based on the most recent sensitivities of the surveillance sputum cultures if available. Otherwise treatment should include coverage of both Staphylococcus and Pseudomonas species. Usually an aminoglycoside (tobramycin) is combined with a beta lactam (ceftazidime, piperacillin-tazobactam, aztreonam or a carbapenem such as meropenem) [13].

As most patients would have been on several classes of antibiotic previously, check for allergies, as these are common.

Bronchodilator therapy

Bronchodilator therapy with β agonists and antimuscuranic agents is used in many patients with CF although there is little evidence of efficacy [22]. In patients with clinical features of bronchial lability, there is little harm in trying nebulised therapy.

Special respiratory scenarios in CF

Haemoptysis

Airway protection and circulatory support should be urgently implemented if deemed necessary on primary assessment in the ED.

Although most cases of major bleeding will stop spontaneously, patients with massive haemoptysis who are clinically unstable should be urgently referred for Bronchial Artery Embolisation (BAE). Failure of BAE should prompt consideration of lung resection.

Of note, investigations such as CT or bronchoscopy should not precede BAE in massive haemoptysis [16].

Pneumothorax

The treatment for pneumothorax in patients with CF is similar to that for secondary pneumothorax in non-CF patients. Asymptomatic small pneumothoraces (≤2 cm) can be observed or aspirated but larger pneumothoraces require a chest drain. An apparently small pneumothorax in a symptomatic patient with advanced CF may need to be drained using CT guidance for symptom relief.
The collapsed lung can be stiff and is associated with sputum retention, thus requiring a longer time to re-expand. During this time other general measures such as supplemental oxygen and appropriate antibiotic treatment are recommended [23]. Non percussive physiotherapy without use of PEP should continue. NIV can be used if a functioning chest drain is sited either as an adjunct to airway clearance or to treat respiratory failure.