ICU 360

Assess risk, avoid unnecessary withholding of contrast, and use isotonic fluids for high-risk patients.

Definition

Contrast-associated AKI (CA-AKI) = AKI within 48-72 h after contrast; contrast-induced AKI (CI-AKI) implies causation. True risk with modern IV contrast is much lower than previously thought, mainly in eGFR < 30 mL/min/1.73 m².

At the bedside

1
Do not delay life-saving imaging
In emergencies (stroke, PE, trauma, dissection, sepsis source) give contrast regardless of creatinine.
2
Assess risk
eGFR < 30 mL/min/1.73 m² (non-dialysis) or AKI = high risk. eGFR 30-44: intermediate (individual decision). eGFR ≥ 45: very low risk.
3
Prophylaxis for high risk
Isotonic crystalloid if not contraindicated (heart failure, overload): e.g. 1 mL/kg/h for 6-12 h before and after (or 3 mL/kg over 1 h before and 1 mL/kg/h for 6 h after for urgent procedures).
4
Use lowest dose of iso- or low-osmolar contrast
Avoid repeated studies within 48-72 h if possible.
5
No N-acetylcysteine or bicarbonate
PRESERVE (2018): neither IV bicarbonate nor oral NAC reduced death, dialysis or persistent kidney decline.
6
Metformin and dialysis
Hold metformin if eGFR < 30 or AKI (lactic acidosis risk). Dialysis patients do not need urgent post-contrast dialysis unless volume overloaded.
7
Check creatinine at 48-72 h
48-72 h
In high-risk patients.

Prophylaxis in high-risk patients

Crystalloid (0.9% saline or balanced)

Dose: 1 mL/kg/h for 6-12 h before and after contrast
Worked example: 70 kg, eGFR 25: 70 mL/h from 6 h before to 6-12 h after CT

Not in heart failure or overload.

Red flag · call your senior now

Withholding contrast CT from a patient with suspected PE, stroke or abdominal sepsis because of 'high creatinine' is more dangerous than CA-AKI.

Pitfall

Blaming contrast for AKI caused by sepsis, hypotension or nephrotoxins given at the same time.

Pearl

Most creatinine rises after CT in ICU patients are coincidental; propensity-matched studies show similar AKI rates with and without contrast at eGFR ≥ 30.

References

Test yourself

Module quiz · score 70% to complete the module

Rhabdomyolysis

Drug dosing in AKI

Educational reference for trained clinicians. Check doses against your hospital protocol and the patient in front of you.

Contrast-associated AKI

At the bedside

Crystalloid (0.9% saline or balanced)

References

Pathophysiology

Evidence

Controversies

🇮🇳 India notes

References