OBJECTIVES: The prevention of delirium is an important issue in the field of 
perioperative nursing. The objective of this study was to verify the usefulness 
of acute-stage bright light exposure on patients following oesophagectomy.
METHODS: The participants were oesophagectomy patients that were removed from 
their ventilators the day after surgery. After extubation, we assigned the 
participants to either the exposure group or control group. At Day 2 after 
surgery, the exposure group underwent two hours of bright light exposure for 
four days. In both groups, we monitored physical activity and autonomic 
activity. In addition, we scored the participants on the NEECHAM Scale and 
evaluated their postoperative delirium and postoperative arrhythmia.
RESULTS: On the nights of Days 4 and 5, the amount of activity of the exposure 
group was significantly lower and The sympathetic nervous index was 
significantly lower on the night of Day 5. The level of arrhythmia was lower in 
the exposure group and we observed a significant difference on the night of Day 
4 and the daytime of Day 5 after surgery. The occurrence rate of postoperative 
delirium tended to be lower in the exposure group, but there was no significant 
difference. None of the participants in the exposure group had NEECHAM Scale 
scores below the cut-off value from the night of Day 4 onwards.
CONCLUSION: We conclude that postoperative bright light exposure adjusted the 
sleep-wakefulness cycle and improved the bed rest of patients. It was also 
indicated that bright light therapy is useful for reducing postoperative 
delirium.