Case Presentation: The patient is a 37-year-old female with a history of substance use disorder on suboxone, nicotine use disorder, type 2 diabetes mellitus, history of hepatitis C, and major depressive disorder, presented to the emergency department after being found unresponsive. Initial evaluation revealed hyperkalemia, leukocytosis, high anion gap metabolic acidosis with lactic acidosis and acute kidney injury (AKI). Laboratory workup demonstrated rhabdomyolysis with creatinine kinase of 11,215. Chest x-ray was concerning for aspiration pneumonia and antibiotics were initiated. CT head and CT spine were negative for acute findings. Patient was transferred to the ICU for worsening metabolic acidosis; ABG showed a pH of 6.99 and intravenous bicarbonate was initiated, followed by endotracheal intubation. She was also diagnosed with diabetic ketoacidosis. Her AKI worsened due to suspected acute tubular necrosis from septic shock with rhabdomyolysis; CRRT was initiated for oliguria and severe acidosis. During toxicology evaluation, additional history revealed that she smokes e-cigarettes daily and recently switched to a new vape. Serum osmolality, osmolar gap, toxic alcohol panel revealed an elevated osmolar gap and toxic panel positive for propylene glycol. Acetaminophen and salicylate acid levels were normal; fomepizole was administered. Evaluation of proteinuria prompted work-up for glomerulonephritis given positive hepatitis C antibody. C3 and C4 were low, likely due to hepatic dysfunction, and rheumatoid factor was negative. CRRT was later transitioned to conventional hemodialysis. Repeat complement was normal; biopsy was deferred. Despite IV Lasix challenge, she had poor renal clearance and remained dialysis dependent. She was ultimately discharged on hemodialysis outpatient with subsequent recovery in coming weeks.
Discussion: With e-cigarettes gaining popularity in young adults, it remains a major public health concern. E-cigarettes contain propylene glycol (PG) and glycerol, along with flavors and nicotine [1]. Propylene glycol and glycerol are the most common vaporizing ingredients found in e-cigarettes, with propylene glycol making up about 95% of the liquid volume [1,4]. It is generally considered safe when ingested in small quantities [1]. However, inhalation of PG can lead to significant toxicity due to the thermal degradation byproducts [2]. Research shows that propylene glycol generates methylglyoxal, an alpha di-carbonyl compound causing epithelial necrosis at lower concentrations of dicacetyl, which is associated with bronchiolitis obliterans [4]. Acute inhaled aerosolized PG is reported to cause cough and throat discomfort [3]. Additional toxic effects include acute kidney injury, increased anion gap metabolic acidosis due to lactic acidosis, and hyperosmolality [5]. In this case, the patient developed severe metabolic derangements, causing a sepsis-like syndrome, leading to acute renal failure requiring dialysis.
Conclusions: This case demonstrates the potential for severe propylene glycol toxicity from vaping products, leading to acute renal failure and dangerous metabolic derangements. Awareness of these toxic exposures when evaluating patients with unexplained high anion gap metabolic acidosis and acute kidney injury is essential. Closer regulations of e-cigarettes and PG ratios can help reduce potential for toxicity. Further research is required to understand long-term health effects of e-cigarettes to strengthen public health policies.