Contrast-induced nephropathy in ITU patients: outcomes of a university hospital re-audit

Introduction

Contrast-induced nephropathy (CIN) is a significant and preventable cause of renal failure associated with increased mortality, hospital stay and long-term haemodialysis. Critically ill patients have increased risks of developing CIN due to pre-existing disease and sepsis. A university hospital audit in 2007 found that 22.2% of ITU patients had significant rises in creatinine following intravenous contrast medium (IVCM). In 2008, IVCM guidelines were implemented trust-wide to detect patients with pre-existing renal impairment and provide guidance for pre-optimisation and prophylactic measures depending on CKD stage, including early renal team involvement. A re-audit assessed the impact of IVCM guidelines in decreasing the incidence of CIN in ITU.

Methods

ITU patients who received IVCM for CT studies from March to December 2010 were identified. Patients on haemodialysis pre-contrast or who died within 48 hours post-contrast administration were excluded. Pre-contrast (within 48 hours) and post-contrast (48 to 72 hours) creatinine levels were analysed. CIN was defined as an increase in serum creatinine exceeding 25% or 44 μmol/l from baseline within 3 days of administration of contrast media in the absence of alternative causes.

Results

Ninety patients were identified. Ten patients who required haemodialysis pre-contrast or died within 48 hours post-contrast were excluded. Mean age was 59 years (range 25 to 89 years) with a male:female ratio of 46:34. Fourteen (17.5%) patients had significant rises in creatinine post-contrast. Patients who died within 48 hours had ruptured AAA, severe sepsis, ischaemic bowel, and so forth.

Conclusions

The incidence of CIN has decreased to 17.5% in medical and surgical ITU patients since the introduction of the IVCM guidelines.