Optic Nerve Sheath Diameter in Acute Liver Failure: A Prospective Cohort Study

Introduction Acute liver failure (ALF) is a rare disease that may lead to cerebral edema and death. An increased optic nerve sheath diameter (ONSD) may reflect an early increase in intracranial pressure. We assessed the feasibility and safety of the ONSD measurement and its association with outcomes in patients with ALF. Methods This was an open-label prospective cohort study including adult patients with ALF admitted to a liver-specialized intensive care unit (ICU) in an academic center between October 2018 and February 2020 (among 24): 20 as intention-to-treat and 17 as per-protocol analyses. The ONSD measurement (primary exposure) used an ultrasound transducer (3 determinations on each eye per patient). The primary outcome was hospital mortality. Results Among the 20 patients, 11 (55.0%) were females and the mean age was 45 ± 16 years. On the day of ONSD measurement (median 32.4 h post-ICU admission; IQR 19.8-59.8): 8 patients (40.0%) were in a coma, the mean international normalized ratio (INR) was 3.3 ± 1.4, median bilirubin was 12.3 mg/dL (IQR 4.7-24.5), mean ammonia was 163 ± 101 µmol/L, and mean SOFA score was 11 ± 5. The mean bilateral ONSD was 5.6 ± 0.7 mm, with a very good correlation between right and left eyes (Pearson's r = 0.90). Ten (50.0%) patients were transplanted and 13 (65.0%) patients survived the hospital stay (all with a 2-month extended Glasgow Outcome Scale of 8). The mean ONSD was significantly higher for hospital non-survivors than survivors both in the intention-to-treat (6.2 vs. 5.3 mm; p = 0.004) and per-protocol (6.2 vs. 5.2 mm; p = 0.004) analyses. No adverse effects from ONSD measurements were reported. Conclusions In patients with ALF, a higher ONSD was associated with higher hospital mortality. ONSD measurement is feasible and safe and may have prognostic value.