Effects of General Anaesthesia on the Sleep Structure of Patients With Prolonged Disorders of Consciousness

Sleep disturbances are common in patients with prolonged disorders of consciousness (pDoC) and are closely correlated with clinical outcomes. With an increasing number of pDoC patients undergoing surgery under general anaesthesia (GA), this study characterized sleep patterns in pDoC patients and evaluated the effects of GA on consciousness and nocturnal sleep. We prospectively enrolled 30 pDoC patients (14 in vegetative state [VS] and 16 in minimally conscious state [MCS]) undergoing spinal cord stimulation and 12 healthy controls. Among pDoC patients, 19 (10 VS, 9 MCS) with complete pre- and postoperative PSG data were analysed for GA effects. Controls underwent one overnight polysomnography (PSG); pDoC patients underwent pre- and postoperative PSG. Consciousness was assessed with Coma Recovery Scale-Revised (CRS-R) before and after surgery. Compared with controls, pDoC patients presented significantly impaired sleep structure, including reduced total sleep time (TST), decreased NREM Stage 2 sleep, diminished slow-wave sleep (SWS), reduced rapid eye movement (REM) sleep duration and percentage relative to TST (all p < 0.05). No significant short-term changes in CRS-R scores were observed following GA. Although GA significantly prolonged TST (p = 0.039), with numerical increases in absolute NREM and SWS durations, no statistically significant changes were observed in sleep stage percentages relative to TST (all p > 0.05). Subgroup analysis showed no significant within-group changes in sleep stage percentages in either the VS or MCS group. These findings suggest that GA increases TST without statistically significant changes in sleep structure in pDoC patients.