Importance: At least 13 medication-associated diethylene glycol (DEG) mass poisonings have occurred since 1937. To our knowledge, this is the first longitudinal study characterizing long-term health outcomes among survivors beyond the acute poisoning period.
Objective: To characterize renal and neurologic outcomes among survivors of a 2006 DEG mass-poisoning event in Panama for 2 years after exposure.
Design, setting, and participants: This prospective longitudinal study used descriptive statistics and mixed-effects repeated-measures analysis to evaluate DEG-poisoned survivors at 4 consecutive 6-month intervals (0, 6, 12, and 18 months). Case patients included outbreak survivors with a history of (1) ingestion of DEG-contaminated medication, (2) hospitalization for DEG poisoning, and (3) an unexplained serum creatinine level of 1.5 mg/dL or higher (to convert to micromoles per liter, multiply by 88.4) during acute illness or unexplained exacerbation of preexisting end-stage renal disease.
Main outcomes and measures: Demographics, mortality, dialysis dependence, renal function, neurologic signs and symptoms, and nerve conduction studies.
Results: Of the 32 patients enrolled, 5 (15.6%) died and 1 was lost to follow-up, leaving 26 patients at 18 months. Three (9.4%) missed 1 or more evaluations. The median age was 62 years (range, 15-88 years), and 59.4% were female. Three (9.4%) patients had preexisting renal failure. Enrollment evaluations occurred at a median of 108 days (range, 65-154 days) after acute illness. The median serum creatinine level for the 22 patients who were not dialysis dependent at time 0 was 5.9 mg/dL (range, 1.8-17.1 mg/dL) during acute illness and 1.8 mg/dL (range, 0.9-5.9 mg/dL) at time 0. Among non-dialysis-dependent patients, there were no significant differences in the log of serum creatinine or estimated glomerular filtration rate over time. The number of patients with subjective generalized weakness declined significantly over time (P < .001). A similar finding was observed for any sensory loss (P = .05). The most common deficits at enrollment were bilateral lower extremity numbness in 13 patients (40.6%) and peripheral facial nerve motor deficits in 7 (21.9%). All patients with neurologic deficits at enrollment demonstrated improvement in motor function over time. Among 28 patients (90.3%) with abnormal nerve conduction study findings at enrollment, 10 (35.7%) had motor axonal involvement, the most common primary abnormality.
Conclusions and relevance: Neurologic findings of survivors tended to improve over time. Renal function generally improved among non-dialysis-dependent patients between acute illness and the first evaluation with little variability thereafter. No evidence of delayed-onset neurologic or renal disease was observed.