Abstract:
It is widely acknowledged that hospitalisation, surgery and anaesthesia cause disturbances to sleep and circadian rhythms in patients. These disturbances are likely due to the disruption of the circadian clock function and are proposed to have major impacts on the health and well-being of chronically ill patients undergoing surgery. I investigated the extent of circadian and sleep-wake cycle disruptions in kidney donor patients as a way of clearly understanding how hospitalisation, anaesthesia and surgery affect the circadian clock and sleep without confounder effects of pre-existing illness. Twelve patients (nine females; three males) undergoing laparoscopic nephrectomy (kidney donation) were studied pre-operatively (one-three weeks before their hospital stay) and post-operatively (during their hospital stay and at the one and three month follow up). The patients’ sleep-wake cycles were measured actigraphically for seven days at each study stage. A 24 hour urine collection was carried out at each study stage to measure urinary melatonin (6-sulphatoxymelatonin (aMT6s), a marker of the circadian clock). Patients also completed fatigue and mood questionnaires at each study stage. Overall the group data revealed a change in the timing and amplitude of aMT6s production. In particular a 52% decline was observed in the overnight 6- sulphatoxymelatonin (aMT6s) from (SEM; range) 897.20 (266.73); 15-2985 ng/mL preoperatively to 428.63 (100.93); 25-1031 ng/mL. By the post-operative one and three month follow ups, overnight (aMT6s) concentrations ha significantly increased. There was a significant decline in the sleep parameters relative amplitude and interdaily stability (p=0.026 and p=0.010 respectively) between the pre-operative stages and post-operative follow ups. Subjective quality of sleep scores indicated a significant decline at the post-operative (hospital) stage (p=0.011). Fatigue increased post-operatively compared to preoperative levels (p=0.005) and persisted until the one month follow up (p=0.039). No major changes were observed in mood between the study stages. This data set establishes some background information on the extent of hospitalisation, surgery and anaesthesia on the circadian clock. Specifically post-operative sleep and circadian disturbances have been observed in a pre-operatively fit and healthy patient population.