Self-treatment of hypoglycemia while driving

Objective: While it is clear that progressive diabetic hypoglycemia leads t o neuroglycopenia, which impairs driving, it is not clear what contributes to patients' detection and subsequent self-correction of hypoglycemia/drivi ng impairments. Drivers with Type 1 Diabetes Mellitus (TIDM) who did and di d not engage in self-treatment during experimental hypoglycemia driving are compared physiologically and psychologically. Method: 38 drivers with TIDM drove a sophisticated driving simulator during euglycemia and progressive hypoglycemia. Subjects were continually monitored for driving performance, EEG activity and whether they self-treated with a glucose drink. Every 5 mi n measures were taken of blood glucose (BG) and epinephrine levels, perceiv ed neurogenic and neuroglycopenic symptoms and driving ability. For the fou r weeks prior to this hospital study, subjects participated in a field stud y. Using a hand-held computer just prior to routine self-measurements of BG , subjects rated neurogenic and neuroglycopenic symptoms and made judgement s about BG level and ability to drive as they did in the hospital. Results: Drivers who did and did not self-treat did not differ in terms of their pr e-hospital exposure to hypoglycemia, their depth and rate of BG fall during experimental testing, or their epinephrine response to hypoglycemia. Subje cts who self-treated detected more neurogenic and neuroglycopenic symptoms than those who did not self-treat. They also experienced less EEG defined n euroglycopenia during the progressive hypoglycemic drive as compared to tho se who did not self-treat. Perceived need to self-treat and EEG parameters correctly classified 88% of those who did treat from those who did not self -treat. Further, subjects who self-treated were more aware of hypoglycemia and when not to drive while hypoglycemic in the field study. Conclusion: Th ere is a narrow window between a patient's detection of hypoglycemic sympto ms and the need to self-treat, and neuroglycopenia, which impairs self-trea tment. Consequently, drivers with TIDM should be vigilant for signs of hypo glycemia and driving impairment (e.g. trembling, uncoordination, visual dif ficulties) and encouraged to treat themselves immediately when they suspect hypoglycemia while driving. (C) 2001 Elsevier Science Ireland Ltd. All rig hts reserved.