Abstract

The relationship between mechanical ventilation-induced brain volume changes and ICU-acquired weakness (ICU-AW) is not clear. We assessed brain volume change in ventilated patients and identified associations with changes in extremity muscle strength. Patients admitted to the ICU due to the need for ventilation, and who underwent at least two head CT scans during hospitalization, were included. We employed an automated segmentation method to measure brain volume, recording changes in volume from baseline. Cases with brain volume reduction > 0% were assigned to the "brain atrophy group" and those with ≤ 0% reduction to the "preserved brain volume group." Medical Research Council (MRC) scores as an indicator of ICU-AW at discharge were compared between groups. There were 84 eligible patients, 71 in the brain atrophy group and 13 in the preserved brain volume group. Analysis of the brain atrophy group showed a significant brain volume reduction of − 3.3% over a median of 30 days. The median MRC scores were significantly lower in the brain atrophy group than in the preserved brain volume group (36 vs. 48, difference [95% CI]: − 12 [− 19.5– − 7.1]). Many ICU patients on mechanical ventilation showed rapidly progressive brain atrophy, and most of these patients developed ICU-AW.