Acute kidney injury — gas and chemistry viva

Stage. Creatinine 340 from a baseline of 95 is more than three times baseline, so this is KDIGO stage 3. Oliguria below 0.5 mL/kg/h for at least six hours also meets the AKI definition.^[4]

Mechanism. Assess perfusion, intrinsic kidney disease and urinary obstruction. Evaluation of kidney function and structure is not complete without urinalysis, urinary sediment examination and imaging studies; diuretics confound FENa, while FEUN below 35 per cent was more useful in the comparison study.^[4][5]

Hyperkalaemia. Potassium 6.7 needs an ECG assessment. Intravenous calcium is given immediately for ECG changes, with insulin and salbutamol to shift potassium; dialysis, binders and loop diuretics remove potassium.^[6]

RRT. Initiate emergently for life-threatening fluid, electrolyte or acid-base changes. Otherwise consider the clinical context and trends rather than single urea or creatinine thresholds; routine accelerated initiation did not improve survival in STARRT-AKI.^[4][7]