966 Minimal Hepatic Encephalopathy and Driving

Abstract

INTRODUCTION: Minimal hepatic encephalopathy (MHE) is a well-known complication of cirrhosis that is difficult to detect. Patients with MHE have deficits in multiple domains that may lead to motor vehicle accidents (MVAs). Clinicians have little guidance on how to manage driving recommendations in this setting. We conducted a systematic review to find studies that indicated the prevalence of MVAs in patients with MHE, testing available to identify such patients, and interventions that may improve the surrogate measures of driving in patients with MHE. METHODS: A systematic review of full-text studies reporting the prevalence of MVAs in patients with MHE, along with testing and treatment options in this setting. Two librarians searched PubMed from inception to January 2018 using the keywords liver cirrhosis, hepatic encephalopathy (HE), automobile driving and accidents along with related synonyms. Studies were excluded if the patients had overt HE, non-liver related HE, and non-automobile accidents. Three reviewers independently extracted data from each study including study design, year of data collection, location, exclusion criteria, prevalence, diagnosis and treatment options. RESULTS: 162 studies were identified, of which 15 met the inclusion criteria, comprising of 1379 patients. Studies were from US(8), Germany(3), Sri Lanka(1), Egypt(1), Japan(1) and Spain(1). Seven articles discussed how often patients with MHE had MVAs, which were conducted as either prospective(5) or survey studies(2) that relied on self-reported and transportation data. These studies suggest that 13–50% of patients with MHE had MVAs. Regarding testing, 10 studies discussed the diagnostic modalities available, including driving simulators(3), inhibitory control tests (ICT)(2), driving instructor(2), smartphone app(1) and Psychometric HE Reliability Score(1). Of these, ICT test was the most predictive. Two studies discussed the treatment modalities. Rifaximin showed improvement in avoiding total driving errors (76%vs31%; P = .01) and branched chain amino acid (BCAAs) significantly improved driving capacity vs placebo (median score of 2 vs 4, P < 0.01) with lower scores indicating the fitness to drive. CONCLUSION: Patients with MHE are at significant risk for MVAs. There are several testing modalities to assess driving fitness in patients with MHE. Rifaximin and BCAAs improved fitness to drive in MHE patients. Future studies are needed to help guide clinicians on how to best provide driving recommendations in patients with MHE.