Prevalence and risk factors for acute kidney injury associated with parenteral polymyxin B use.

BACKGROUND

The main adverse effect of polymyxin B is nephrotoxicity. There are few data on polymyxin-associated renal injury.

OBJECTIVE

To assess the prevalence of and risk factors for acute kidney injury (AKI) in patients treated with polymyxin B.

METHODS

The studied population included 114 patients who received at least 3 consecutive days of intravenous polymyxin B and had baseline serum creatinine (SCr) and at least one further SCr measurement during treatment. AKI was defined as an SCr increase to 1.8 mg/dL or greater in patients with baseline SCr less than 1.5 mg/dL, or an increase greater than or equal to 50% in baseline SCr when it was already greater than or equal to 1.5 mg/dL, or need for dialysis.

RESULTS

AKI developed in 22% of the patients. They were older, had a higher baseline SCr, had a higher frequency of baseline SCr greater than or equal to 1.5 mg/dL, used other nephrotoxic drugs and furosemide more often, and required vasoactive drugs and mechanical ventilation more frequently. Progression to renal failure was significantly more probable when the bacteria were isolated in the abdomen, catheter, or blood. AKI patients had a higher mortality rate (92% vs 53%; p < 0.001). Logistic regression identified abnormal baseline SCr (odds ratio [OR] 3.51); need for vasoactive drugs (OR 3.03); and abdomen, blood, or catheter as the infection site (OR 3.82) as independent risk factors for AKI.

CONCLUSIONS

Patients who developed AKI had a strikingly elevated mortality rate. Polymyxin B should be used with extreme caution in patients who have an abnormal baseline SCr; use vasoactive drugs; or have abdomen, blood, or catheter as the infection site.