Alertness Degradation and Circadian Disruption on a U.S. Coast Guard Cutter Under Paragon Crewing Limits
COAST GUARD RESEARCH AND DEVELOPMENT CENTER GROTON CT
Pagination or Media Count:
Crew alertness and the incidence of sleepwake cycle disruptions were evaluated aboard DEPENDABLE, a WMEC, throughout 32 consecutive days underway. This study was conducted during the implementation of crew reductions prescribed by the Paragon project. Thirty male crew members volunteered to participate in the study. Wrist activity monitors WAMs were used to document sleepwake cycles and electroencephalography EEG techniques were used to measure alertness. Thirty participants wore WAMs throughout the study period, while a subset of 14 volunteers participated in short duration EEG alertness tests every three to five days. Alertness tests were administered within three hours of wakefulness from daily sleep. Participants were allowed to follow their daily routine prior to reporting for the wakefulness tests. Unremarkable weather conditions and low operational tempo characterized this patrol. However, analysis of sleepwake cycles and EEG alertness tests revealed a 59 percent incidence of sleepwake cycle disruption associated with high failure rates in the EEG alertness tests. Twelve out of the 14 EEG participants failed to maintain wakefulness in 50 to lOO percent of the tests. Participants working under non-rotating watch schedules e.g., 0400-0800 exhibited consistent patterns of sleep and wake-up times with sleep duration rarely dipping below six hours. In contrast, participants exposed to frequent watch rotations showed disrupted sleep associated with the 0000-0400 and 0400-0800 watch schedule. Recommendations include the implementation of a a crew endurance education program to optimize the quality of crew rest b watch schedules that minimize sleepwake cycle disruptions c the development of a system to reduce crew members frequent rotation into the 0000-0400 or 0400-0800 watch schedules.
- Anatomy and Physiology
- Stress Physiology