Severe methanol poisoning. Application of a pharmacokinetic model for ethanol therapy and hemodialysis.

Two patients with extremely high blood methanol concentrations (260 and 282 mg/dl) were successfully treated using pharmacokinetic dosing of ethanol, hemodialysis and supportive measures. Both patients recovered completely without residual ophthalmologic deficits. Early hemodialysis and inhibition of methanol metabolism with effective ethanol concentrations were attributed to the patients' full recovery. Methanol elimination was enhanced by hemodialysis as evidenced by a decrease in half-life from eight to two and a half hours. Methanol dialysance was 98 ml/min. A dosage regimen for ethanol was devised, utilizing dose-dependent pharmacokinetic parameters and the ethanol dialysance (100 to 120 ml/min) from these two patients. An ethanol loading dose of 0.6 g/kg should be administered to an adult with an acute methanol ingestion. This dose will produce a blood ethanol concentration of approximately 100 mg/dl which can be maintained by an ethanol infusion of 66 mg/kg/hour for nondrinkers to 154 mg/kg/hour for chronic ethanol drinkers. Hemodialysis should be initiated if the blood methanol concentration is greater than 50 mg/dl. If hemodialysis is initiated, the ethanol infusion should be increased by 7.2 g/hour.

Prevention of chloramine-induced hemolysis in dialyzed patients.

Chloramines, compounds made up of chlorine and ammonia, when present in tap water used for dialysis cause methemoglobinemia and hemolysis. Ascorbic acid addition has been reported to effectively neutralize chloramines in vitro and in patients dialyzed with the single batch dialysis delivery system. We extended these observations to patients dialyzed with the proportioning dialysis delivery system where exposure time of ascorbic acid to chloramines is shorter. This may be important since we found that the half time of the reaction between ascorbic acid and chloramines is 4 minutes. Red cell oxidant sensitivity in 15 patients was assessed by incubating red cells with ascorbate-cyanide and measuring methemoglobin which averaged 2.17 +/- 0.42 g/100 ml (SEM) before dialysis and 2.87 +/- 0.52 g/100 ml after dialysis (NS). Reduced glutathione (GSH) levels were also measured as an index of red cell oxidant damage. GSH decreased from a mean of 7.40 +/- 0.59 micromoles/g Hb before dialysis to 6.98 +/- 0.52 micronmoles/g Hb after dialysis (P less than 0.01). In 2 patients there was no change in 51Cr red cell survival when dialyzed on either the proportioning system or other chloramine free systems. We conclude that addition of ascorbic acid to neutralize chloramines in tap water is also effective when using the proportioning dialysis delivery system.

Massive theophylline overdose. Rapid elimination by charcoal hemoperfusion.

Shock, seizures, cardiac arrhythmias, and respiratory and cardiac arrests developed in a patient who ingested 8.5 g of theophylline. Her condition improved and her serum theophylline concentration decreased from 170 to 20 mg/ml during six hours of charcoal hemoperfusion. Theophylline was removed from the serum by the uncoated charcoal column, as shown by an extraction efficiency approaching 100%. The maximum charcoal clearance of theophylline was 163 ml/kg/hr. The average endogenous theophylline clearance in adults is 50 ml/kg/hr and that achieved with hemodialysis is only 24.3 ml/kg/hr. Uncoated charcoal efficiently removes theophylline from the serum; charcoal hemoperfusion should be considered in severe theophylline toxic reactions.

Acute reversible renal failure following jejunoileal bypass for morbid obesity: a clinical and pathological (EM) study of a case.

A patient who underwent jejunoileal bypass for morbid obesity developed servere renal failure associated with hyperoxaluria and renal oxalosis. Renal function improved and oxalate excretion decreased following hemodialysis and restoration of gastrointestinal continuity.