Name: Acute kidney injury — bulletproof documentation — ER Toolkit
Creator: Kim Trinh, MD

An elevated creatinine is rarely the emergency — its complications are. The defensible chart documents the potassium and the ECG, rules out the obstruction you can relieve with a catheter or a nephrostomy, distinguishes pre-renal from intrinsic disease, stops the nephrotoxins, and recognizes when dialysis can't wait.

01What's at stake

AKI kills through its complications: hyperkalemia causes arrhythmia, severe acidosis and uremia and fluid overload threaten the airway and heart, and an obstructed system that isn't decompressed loses nephrons by the hour. The two fast wins are an ECG for the potassium and a bladder scan/ultrasound for obstruction — both can be done in minutes and both change everything.

02Can't-miss issues

Hyperkalemia — the lethal complication; get an ECG immediately and treat empirically while awaiting the level. → ECG now
Obstruction (post-renal) — a distended bladder relieved by a catheter, or hydronephrosis needing decompression; reversible if caught. → bladder scan / US
Emergent dialysis indications — refractory hyperkalemia, severe acidosis, fluid overload/pulmonary edema, uremia (pericarditis, encephalopathy), and certain toxins (the "AEIOU").
Pre-renal (hypovolemia, sepsis, cardiorenal) vs intrinsic (ATN, glomerulonephritis, interstitial nephritis, rhabdomyolysis, contrast) — the distinction drives therapy.

03Assessment

Potassium & ECG — check the K⁺ and obtain an ECG; don't wait for the lab if the story fits. → K⁺/ECG
Rule out obstruction — bladder scan/post-void residual and renal ultrasound for hydronephrosis. → bladder/US
Volume status — exam, vitals, response to a fluid challenge; pre-renal vs intrinsic. → volume
Stop nephrotoxins — NSAIDs, ACEi/ARB, contrast, aminoglycosides; review the med list. → nephrotoxins
Urinalysis (casts, blood, protein), CK for rhabdomyolysis, and the precipitant search.

Skip the typing

Work the case in the Acute Kidney Injury Workup — it records the potassium/ECG, the bladder scan and ultrasound, the volume assessment, and the nephrotoxin review, and assembles an MDM that documents the reversible causes and dialysis indications were addressed.

04Management

Hyperkalemia: calcium for membrane stabilization, insulin/dextrose and albuterol to shift, and definitive removal (diuresis, binders, or dialysis).
Obstruction: bladder catheter for outlet obstruction; urology/IR for upper-tract obstruction (stent/nephrostomy), especially if infected.
Pre-renal: judicious fluids and treat the cause (sepsis, hemorrhage, cardiorenal — which may need the opposite).
Intrinsic: remove the insult; nephrology for glomerulonephritis/interstitial nephritis; aggressive fluids for rhabdomyolysis.
Dialysis for the refractory/emergent indications; admit the significant or symptomatic AKI.

05What to document

▼ weak

"Creatinine 3.2, up from baseline. AKI, gave fluids, admitted."

▲ defensible

"Creatinine 3.2 (baseline 1.0), oliguric. K⁺ 5.1 with a normal ECG (no peaked T waves) — monitored, treated. Bladder scan 40 mL and renal ultrasound without hydronephrosis — obstruction excluded. Hypovolemic on exam (poor intake, vomiting) — pre-renal picture; responded to a fluid challenge with improved urine output. NSAIDs and ACE inhibitor held; no contrast. No dialysis indication (no refractory hyperkalemia, severe acidosis, overload, or uremia). Admitted for AKI with serial K⁺/renal function and nephrology input; return/escalation plan documented."

06Where charts fail

Not checking a potassium/ECG in significant AKI.
Missing reversible obstruction — no bladder scan or ultrasound.
Continuing NSAIDs/ACEi/contrast (or giving contrast) without documenting the nephrotoxin review.
Reflex fluids in cardiorenal/overloaded AKI, or under-resuscitating pre-renal AKI.
Not recognizing an emergent dialysis indication.

07Sources

Kidney Disease: Improving Global Outcomes (KDIGO) Acute Kidney Injury Work Group. KDIGO clinical practice guideline for acute kidney injury. Kidney Int Suppl. 2012;2(1):1-138.
Rahman M, Shad F, Smith MC. Acute kidney injury: a guide to diagnosis and management. Am Fam Physician. 2012;86(7):631-639.
Levi TM, de Souza SP, de Magalhães JG, et al. Comparison of the RIFLE, AKIN and KDIGO criteria. Rev Bras Ter Intensiva. 2013.
Lentini P, Zanoli L, Ronco C. Sequential approach to hyperkalemia and AKI in the emergency department. Int Urol Nephrol. 2018.

Acute kidney injury: documentation that holds up