The "Mellanby effect" in alcoholised e-scooter drivers.

PURPOSE: Several studies tried to discuss and clarify the so-called Mellanby effect: Similar blood alcohol concentrations (BACs) supposedly lead to more signs of impairment in the phase of alcohol resorption than elimination. To assess this effect for alcoholised e-scooter driving, results of a real-driving fitness study were subanalysed. METHODS: Sixteen subjects (9 females; 7 males) who completed runs at comparable BACs in the phases of alcohol resorption and elimination were chosen to assess a possible "Mellanby effect". The data of the subjects was taken from a prior e-scooter study by Zube et al., which included 63 subjects in total. RESULTS: In the phase of alcohol resorption, the relative driving performance was approx. 92% of the phase of elimination (p value 0.21). Statistically significant more demerits were allocated to the obstacle "narrowing track" in the phase of resorption than elimination. Subjects also needed significantly more time to pass the obstacles "narrowing track", "driving in circles counterclockwise" and "thresholds" in the phase of resorption than elimination. DISCUSSION: The most relevant obstacle to discriminate between the two different states of alcoholisation was the narrowing track. Insofar, measurements of the standard deviation of the lateral position (SDLP) might also be a sensitive component for the detection of central nervous driving impairment during shorter trips with an e-scooter. Additionally, driving slower during the phase of alcohol resorption seems to be the attempt to compensate alcohol-related deficits. CONCLUSION: The results of the study suggest a slight Mellanby effect in e-scooter drivers.

E-scooter driving under the acute influence of alcohol-a real-driving fitness study.

PURPOSE: To assess the effects of alcohol on the ability to drive an e-scooter, driving tests reflecting real-life situations accompanied by medical examinations focusing on balance were conducted at different blood alcohol concentrations (BACs). METHODS: Fifty-seven subjects who consumed alcohol (28 female, 29 male) and 6 consistently sober subjects (3 female, 3 male) participated in the study. Alcohol was administered on a fixed schedule, and the individual drinking quantity was individually calculated in advance using the Widmark formula. Repeated runs through a fixed course were performed. Following each ride, a blood sample was taken for BAC determination, and medical tests were performed. RESULTS: Even at low BACs (0.21-0.60 g/kg), subjects showed a significant decrease in driving performance, to approximately 60% of the initial level. Differences in driving performance at different BAC ranges were observed for different obstacles, especially for the narrowing track, gate passage, slalom, and driving in circles obstacles. Furthermore, worse Romberg and Unterberger test results were correlated with worse driving performance. It cannot be assumed that learning effects during the study had a relevant effect, as shown in the comparison of the driving performance of the alcohol-consuming group with that of the control group. Sex-specific differences were not found. DISCUSSION: Significant deteriorations in driving performance at BACs below 1.10 g/kg confirmed alcohol-related risk potential when using e-scooters. At this time, these findings may lead to the assumption of "relative driving impairment" in Germany. The Romberg and Unterberger tests could be considered a complementary investigation method for the assessment of e-scooter driving impairment. CONCLUSION: Even at rather low BACs between 0.21 and 0.40 g/kg, there was a significant deterioration in driving performance under the influence of alcohol compared to sober, which highlights the negative effects of alcohol on e-scooter driving.