What criteria should I use to determine when to refer a patient with suspected Goodpasture's syndrome to a nephrologist or pulmonologist?

Referral criteria for suspected Goodpasture's syndrome:

• Refer to a nephrologist if there is evidence of kidney involvement such as: haematuria, significant proteinuria (albumin-to-creatinine ratio [ACR] >30 mg/mmol with haematuria), rapidly declining estimated glomerular filtration rate (eGFR) (e.g., sustained decrease in eGFR of 25% or more within 12 months or a decrease of ≥15 ml/min/1.73 m2 per year), or a high risk of progression to renal replacement therapy (greater than 5% over 5 years) NICE NG203.
• Refer to a pulmonologist if there are respiratory symptoms suggestive of pulmonary involvement such as: haemoptysis, persistent breathlessness, cough, or evidence of pulmonary haemorrhage on imaging or clinical examination NICE NG115,NICE CG163.
• Urgent referral is warranted if there is clinical suspicion of rapidly progressive glomerulonephritis or pulmonary haemorrhage, as Goodpasture's syndrome is a medical emergency requiring specialist input.
• Multidisciplinary assessment is recommended when diagnosis is uncertain or when both renal and pulmonary involvement coexist, to coordinate care between nephrology and respiratory specialists.

In summary, refer patients with suspected Goodpasture's syndrome promptly to nephrology if there is kidney involvement or rapid renal function decline, and to pulmonology if there are respiratory symptoms or haemorrhage. Early specialist involvement is critical for diagnosis confirmation and management.