Fatal Prognosis of Methanol Toxicity: Identification of Predictive Factors,NABIL N. REZK and MOHAMAD F. ALLAM
Abstract
Human methanol poisoning is characterized by serious visual impairment, hepatic toxicity, formic acidosis, central nervous system toxicity, and death. This study was conducted on all patients admitted to Ain Shams Toxicology Centre because of methanol toxicity over one year, form January 1, 2004 to December 31, 2004. The patients were divided into two main groups; Group I included patients who survived after methanol poisoning meanwhile group II included patients who died after methanol poisoning. All patients were clinically examined for cardiovascular system manifestations, neurolog-ical, ophthalmic ad effects of acidosis. All patients were subjected to routine investigation including renal profiles and liver profiles, as well as specific investigations mainly arterial blood gases and serum electrolytes. Also, data about if the patient was in need for and had haemodialysis was registered. Patients in group I presented with tachycardia, hypertension, pallor, sweating, blurring of vision, and some of them were agitated. On the other hand patients in group II showed hypertension, arrhythmias, convulsion and coma (grade III, IV), elevated renal profiles (serum creatinine mainly), together with hyperkalaemia and sever acidosis. Comparisons between group I and group II were done using student’s t-test for continuous variables and Person’s Chi-square test for categor-ical variables. The adjusted predicted factors for fatal prognosis were obtained using the logistic regression analysis. The results of the study revealed that mortality was much more prevalent among those who suffered from significant cardio-vascular, CNS, ophthalmic, and renal signs of toxicity together with metabolic acidosis and hyperkalaemia.
The multivariable analysis has identified one independent predictive factor significantly associated with fatal prognosis. This factor was convulsion (p<0.001). It can be concluded that early diagnosis and management of methanol poisoning may improve survival. Also, cardiovascular, CNS toxic man-ifestations and metabolic acidosis were strong predictors of methanol poisoning out come. Our results call for further investigation of predictive risk factors for the fatal prognosis of methanol toxicity; future studies preferably should include measuring of serum and tissue formic acid, and performed on large prospective cohorts over several years, to increase their internal validity.