Granulomatosis with Polyangiitis (GPA)

Subglottic stenosis is the lesion that changes your tube - Subglottic and bronchial stenosis are recognized complications of GPA. They can be silent early, or announce themselves as hoarseness, cough, wheeze or stridor. Ask directly about voice change and noisy breathing on exertion, and look at any recent neck or chest CT - sinus, lung, tracheal and orbital imaging is usually already on file because it is used to stage the disease. A stenosis below the cords is not solved by a video laryngoscope; it is solved by a smaller tube. Bring endotracheal tubes several sizes below what you would normally choose, and be prepared for the case to become a tracheostomy.

Don't go through the nose - Roughly 90% have upper respiratory involvement: nasal and sinus pain, purulent discharge, nasal ulceration, crusting rhinitis, epistaxis, septal perforation and nasal bridge collapse. Nasal intubation, nasal airways, nasogastric tubes and nasal temperature probes all risk brisk bleeding into an airway that may already be narrowed. Go oral.

Mask fit and the saddle nose - Nasal bridge collapse changes the geometry the mask has to seal against. Anticipate a leak, and have an oral airway and a two-handed technique ready before you need them.

Renal function will surprise you - Only 10-20% have renal involvement at presentation, but glomerulonephritis develops in 80% within two years, most commonly rapidly progressive crescentic glomerulonephritis heading toward chronic or end-stage kidney disease. A creatinine from six months ago tells you nothing. Get a current creatinine, potassium and urinalysis, and check the potassium before succinylcholine.

Pulmonary involvement, two flavors - Nearly 50% present with unilateral or bilateral pulmonary infiltrates, pulmonary nodules (coin lesions) are common, and pleural effusion appears in 15-20%. Diffuse pulmonary hemorrhage is the one that causes significant morbidity and mortality. KCO rises in profuse pulmonary hemorrhage because free red cells in the alveoli take up carbon monoxide, so a high DLCO here means blood, not healthy lung. Expect refractory hypoxemia, plan for repeated suctioning, and consider lung isolation if bleeding localizes.

Eyes are involved more often than you'd expect - More than half have eye involvement: scleritis, episcleritis, conjunctivitis and anterior uveitis, with necrotizing anterior scleritis capable of ending in blindness and peripheral ulcerative keratitis threatening corneal melt. Orbital pseudotumor in the retrobulbar region occurs in 10-15% and causes proptosis and diplopia, so the globe may not close under anesthesia. Lubricate and tape deliberately, and document any pre-existing visual deficit before induction.

Neurologic and cardiac involvement - Nervous system involvement occurs in 30-40%, most often peripheral neuropathy and mononeuritis multiplex, with cranial neuropathies, pachymeningitis, seizures and cerebritis also reported. Document existing deficits preoperatively so a postoperative finding isn't attributed to your block or positioning. Cardiac involvement is less common but includes valvular lesions or insufficiency, pericarditis and coronary arteritis - a new murmur in a GPA patient earns an echo.

Hearing loss changes the preop conversation - Conductive loss from auditory tube dysfunction secondary to nasopharyngeal disease is common, and sensorineural loss with vestibular dysfunction occurs; serous otitis media and mastoiditis are seen. Confirm the patient actually heard the consent discussion, and don't read a slow response on emergence as confusion.

Heavy immunosuppression - Induction for severe disease is cyclophosphamide plus glucocorticoids, often after three days of pulse steroids, or rituximab, which the RAVE trial found non-inferior to daily cyclophosphamide and possibly superior in relapsing disease. Maintenance with methotrexate, azathioprine or rituximab runs 12 to 36 months after remission. Plasmapheresis is added for rapidly declining kidney function, positive anti-GBM antibodies, or pulmonary hemorrhage with respiratory compromise not responding to IV glucocorticoids. Strict asepsis for lines and blocks, and check the counts before a neuraxial.

Check what else is driving it - Hydralazine, phenytoin, antithyroid medications, sulfasalazine and allopurinol have all been implicated in ANCA-associated vasculitis. Reconcile the home medication list, because one of them may be part of the problem you are anesthetizing around.

Granulomatosis with polyangiitis (GPA), formerly Wegener granulomatosis, is a necrotizing small- to medium-vessel vasculitis and the most common of the ANCA-associated vasculitides. Antibodies against proteinase 3 activate neutrophils, which adhere to endothelium and degranulate, damaging endothelial cells. Cytoplasmic-ANCA against PR3 is present in 80-90% of cases, and ANCA overall is 66% sensitive and 98% specific.

The lesion is a poorly formed granuloma of giant cells, plasma cells, lymphocytes and dendritic cells that penetrates submucosa, cartilage and bone, producing necrosis and permanent deformity rather than simple inflammation. The classic triad is upper airway, lung and kidney: sinusitis and crusting rhinitis progressing to septal perforation and saddle nose, pulmonary nodules and alveolar hemorrhage, and crescentic glomerulonephritis. For anesthesia, the destructive airway involvement is what changes the plan.