Polymyxin B-associated AKI affects 25% of septic shock patients; BMI and comorbidities are key risk factors

Patients with septic shock and multidrug-resistant gram-negative infections often require polymyxin B, a critical 'last-line' antibiotic. Despite its efficacy, polymyxin B is notoriously nephrotoxic, posing a significant challenge in critically ill patients already at high risk for acute kidney injury (AKI) due to their underlying condition. Understanding specific risk factors and implementing effective surveillance strategies are crucial to mitigate this severe complication and improve patient outcomes.

Researchers conducted a prospective cohort study involving 200 adult patients diagnosed with microbiologically confirmed multidrug-resistant gram-negative infections and septic shock. All participants received intravenous polymyxin B with standardized dosing. Renal function was meticulously monitored using Kidney Disease Improving Global Outcomes (KDIGO) criteria. The primary endpoint was the incidence of polymyxin B-associated AKI, with secondary analyses identifying associated risk factors.

Acute kidney injury (AKI) developed in 25% of the 200 patients receiving polymyxin B, with a median onset of 4 days after therapy initiation.

Significant risk factors for polymyxin B-associated AKI included a higher baseline body mass index (BMI), elevated serum urea and creatinine levels, and a reduced glomerular filtration rate (GFR). The presence of comorbidities and the concomitant use of other nephrotoxic agents also significantly increased the risk. Structured nursing interventions and standardized monitoring protocols proved effective in enabling early detection of renal dysfunction, facilitating timely dose adjustments to manage the nephrotoxic effects of polymyxin B.