Has multiple causes (see Box 5.1). A triad of:
• Diffuse alveolar infiltrates
• Haemoptysis (although not always present)
• A fall in Hb or haematocrit.
* Indicates conditions commonly considered in the differential diagnosis of pulmonary-renal syndrome (diffuse alveolar haemorrhage with glomerulonephritis). Note: conditions causing diffuse CXR infiltrate and renal failure may mimic these, e.g. severe cardiac failure, severe pneumonia, leptospirosis.
Bleeding into the alveoli is often a feature of a small-vessel vasculitis of the lungs. Most of this blood tends to remain in the lungs and is not expectorated. Patients with diffuse alveolar haemorrhage may have a background history of vasculitis over the preceding weeks to months. They can present with slowly progressive dyspnoea with haemoptysis or be acutely unwell with hypoxia. They may require ventilatory support.
Abrupt-onset haemoptysis is the most common symptom, although this is not present in one-third of cases. Also cough, dyspnoea, low-grade fever, weight loss, arthralgia, myalgia. There may be a history of chronic sinusitis and other ENT symptoms (granulomatosis with polyangiitis; GPA ≈ Wegener’s).
May be non-specific or may have signs of underlying vasculitis with skin rashes, nail fold infarcts, digital gangrene. Episcleritis, corneal ulceration, epistaxis, nasal crusting, or deafness may be present. Neurological signs, including mononeuritis multiplex, should raise the possibility of vasculitis. Patients may be breathless. Haematuria and proteinuria on urine dip.
• May be hypoxic—check SaO2 ± ABG
• FBC—?falling Hb, clotting profile
• Creatine kinase (CK)
• CXR showing bilateral alveolar infiltrates—difficult to distinguish from pulmonary oedema or infection
• Consider chest HRCT
• Raised kCO, as increased intra-alveolar Hb is available to combine with carbon monoxide (CO). Abnormal if raised by >30%. If breathless at rest, they will not be able to perform this test, as it requires breath-holding of an air, CO, and helium mixture for 10s. This test can be used to monitor disease progress
• BAL shows bloodstained lavage, which becomes sequentially more so with each washing. Cytology shows haemosiderin-laden macrophages
• Renal involvement: blood and/or protein in the urine, red cell casts, raised urea, and creatinine
• Send blood for urgent complement levels, ANA, ANCA (PR3 and MPO), anti-GBM Ab, anti-dsDNA Ab, antiphospholipid Ab, and rheumatoid factor (RhF)
• Consider biopsy of lung, kidney (if acute glomerulonephritis present), or other affected site if well enough to make a tissue diagnosis. Transbronchial biopsy (TBB) specimens are usually insufficient to make a diagnosis of vasculitis, and a surgical lung biopsy may be required. Capillaritis (a neutrophilic vasculitis of capillaries and venules), haemorrhage, or diffuse alveolar damage with haemorrhage seen on lung biopsy.
Management of alveolar haemorrhage
• Admit to hospital
• Supportive treatment, with IV fluids, blood transfusion, and O2, if necessary
• Monitor, paying particular attention to O2 saturations and keeping them above 92% with O2 therapy. May need respiratory support with intubation and ventilation or CPAP. Monitor Hb, and transfuse, if necessary. Monitor urine output and renal function
• Aim to establish the underlying diagnosis, usually with tissue biopsy
• Treatment with plasma exchange, high-dose steroids and cyclophosphamide, and dialysis, if required.