What are the referral criteria for patients with abnormal pulmonary function test results?

Referral criteria for patients with abnormal pulmonary function test (PFT) results include the following clinical indications:

• Diagnostic uncertainty requiring confirmation and optimisation of therapy.
• Suspected severe chronic obstructive pulmonary disease (COPD) to confirm diagnosis and optimise treatment.
• Patient requests a second opinion regarding their respiratory condition.
• Onset of cor pulmonale (right heart failure secondary to lung disease).
• Assessment for oxygen therapy, long-term nebuliser therapy, or oral corticosteroid therapy to optimise treatment and justify ongoing management.
• Presence of bullous lung disease to identify candidates for lung volume reduction procedures.
• Rapid decline in forced expiratory volume in 1 second (FEV1) to encourage early intervention.
• Assessment for pulmonary rehabilitation, lung volume reduction procedures, or lung transplantation to identify surgical or therapeutic candidates.
• Dysfunctional breathing requiring confirmation of diagnosis and optimisation of pharmacotherapy.
• Onset of symptoms under 40 years or family history of alpha-1 antitrypsin deficiency to consider genetic screening and therapy.
• Symptoms disproportionate to lung function deficit, suggesting alternative diagnoses such as cardiac impairment or pulmonary hypertension.
• Frequent respiratory infections to exclude bronchiectasis.
• Haemoptysis to exclude bronchial carcinoma.

Additionally, patients with abnormal PFTs and unexplained respiratory symptoms such as persistent cough, chest pain, or shortness of breath, especially if aged 40 or over and with risk factors like smoking or asbestos exposure, should be considered for urgent chest X-ray and possible referral for suspected cancer pathways.

In motor neurone disease, referral to respiratory ventilation services is indicated if oxygen saturation is ≤92% (with lung disease) or ≤94% (without lung disease), or if arterial partial pressure of carbon dioxide (PaCO2) is >6 kPa, or if sleep-related respiratory symptoms are present despite normal saturation.

Referral may be appropriate at all stages of disease and is not limited to the most severe cases. Some referrals may be managed by trained COPD team members rather than respiratory physicians.

These criteria ensure timely specialist assessment to confirm diagnosis, optimise therapy, and consider advanced interventions.

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