Creatine kinase and McMahon score as predictors for acute kidney injury, renal replacement therapy, and mortality associated with poisoning-induced rhabdomyolysis

Abstract

Background: Poisoned patients presenting with rhabdomyolysis are at a higher risk of Acute Kidney Injury (AKI), and consequently, an increased risk of Renal Replacement Therapy (RRT) and mortality. We aimed to compare the prognostic significance of creatine kinase (CK) with the McMahon score for AKI, RRT, and mortality in acutely poisoned patients with rhabdomyolysis.

Methods: This prospective study included 50 patients admitted to the Intensive Care Unit (ICU) with poisoning-induced rhabdomyolysis between the beginning of January 2023 and the end of September 2023.

Results: The incidence of rhabdomyolysis was 6.6% in a total of 949 acutely poisoned patients. AKI and mortality rates were 34% and 6% respectively. Antipsychotics were the leading cause of rhabdomyolysis (52%), while substance abuse was the most common cause in the AKI group (58.9% of the AKI group). The initial CK and McMahon scores could predict AKI at the optimum cut-off values of CK > 982 and McMahon score > 6, with an AUC of 0.712 and 0.807, respectively.

Conclusion: The variables independently associated with AKI development were age > 33 years, McMahon score ≥ 6, and WBC count > 18 (10³/µL). The McMahon score is superior to CK in predicting the need for hemodialysis and mortality.

Keywords: Antipsychotics; Poisoning – intensive care unit (ICU); Renal replacement therapy; acute kidney injury (AKI); rhabdomyolysis.