Microscopic Polyangiitis

MPA should trigger a kidney–lung assessment rather than a single-organ assessment. New haematuria, proteinuria, or a rapidly rising creatinine may represent pauci-immune glomerulonephritis; falling haemoglobin, new bilateral infiltrates, hypoxaemia, or even a cough without visible blood may signal pulmonary capillaritis and alveolar haemorrhage. The experienced nurse connects these findings early because both organs can deteriorate quickly. Check urine output and character, blood pressure, oxygenation, work of breathing, haemoglobin trend, skin, and peripheral neurological function. The combination of renal injury and pulmonary bleeding is an escalation pattern, not a routine inflammatory flare.