Approche psychiatrique des troubles mentaux de Friedrich Nietzsche (traité d'insubordination)

LYON1-BU Santé (693882101) / SudocPARIS-BIUM (751062103) / SudocPARIS-Bib. Serv.Santé Armées (751055204) / SudocSudocFranceF

Sleeping under the Ocean: Despite Total Isolation, Nuclear Submariners Maintain Their Sleep and Wake Patterns throughout Their Under Sea Mission.

To assess the effects of isolation, inadequate exposure to light and specific shift work on the subjective and objective measurements of sleep and alertness of submariners.A strictly controlled randomized crossover study with the polysomnography recorded twice during the mission.Setting: Shift and night work with prolonged (70 days) social isolation from the real world (with no phone or Internet contact with families or friends during a routine mission aboard the "Téméraire" French Strategic Submarine with Ballistic Nuclear missiles (SSBN). Participants: 19 submariners working on a 24-hour shift for three days in a row schedule. Interventions: The participants attended two polysomnographic (PSG) recordings of night sleep on Day 21 (D21) and Day 51 (D51) of the 70-day patrol; urine cortisol levels were also taken after sleep, and subjective assessments of sleep, sleepiness, mood and anxiety on D21 and D51. The light and temperature on board were also recorded.PSG analyses showed that sleep did not significantly vary in length (total sleep time) or in quality between D21 and D51. The mariners reported the same subjective sleep, sleepiness, anxiety or mood (except for a slightly worse score for confusion on D51). Blood cortisol levels did not vary significantly.These results show that humans living in an isolated environment for more than two months with this specific shift schedule do not suffer from any significant effects on sleep, sleepiness and confusion between D21 and D51, when they follow an organized regular shift pattern with controlled light and temperature

Correlation between objective polysomnographic results and subjective (Buguet and POMS) on D51.

<p>These tables present correlations between subjective assessments of sleep (Buguet sleep Scale (Buguet et al., 1981)and POMS (Profile of Mood Scale; Shacham, 1983) and objective measurements by polysomnography on the 21^st day (D21) and the 51st day (D51) of the mission. SOL = Sleep Onset latency; TSP = Total sleep period; TST = Total Sleep Time; WASO = Wake after sleep onset; SE = sleep Efficiency 1; %REM = percentage of Rapid Eye Movement sleep; %SWS: percentage of slow wave sleep; <b>significant correlations are bolded.</b></p><p>Correlation between objective polysomnographic results and subjective (Buguet and POMS) on D51.</p

Schedules of submariners on a 3 days cycle.

<p>Schedules of submariners on a 3 days cycle.</p

Subjective and objective sleep variables, sleepiness and mood at D21 and D51.

<p>Subjective and objective sleep variables, sleepiness, cortisol, mood and anxiety were assessed on the 21st day of the mission, D21, and 30 days later (after 10 shifts) at D51 = the 51st day. Values were compared using student “t” comparison tests between session-points. No significant differences were observed in subjective values of the quality of sleep and ease of falling asleep assessed on visual analogue scales (VAS) or sleep onset latencies (SOL) expressed in minutes (min) or on the number of awakenings. There was also no statistical difference in sleepiness over the last month on the Epworth sleepiness scale [<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0126721#pone.0126721.ref011" target="_blank">11</a>]. Objective sleep values measured by polysomnography (PSG) were also not significantly different between D21 and D51, including: SOL, total sleep period (TSP), total sleep time (TST), wake after sleep onset (WASO), sleep efficiency 1 (SE1) = TST/TSP, sleep efficiency 2 = TST/time in Bed (TIB), the percentages (%) of rapid eye movement (REM) sleep and slow wave sleep (SWS) and the REM latency. No significant difference was observed in the 12-hour night-cortisol excretion assessed on the same days. Mood and anxiety were assessed based on the profile of mood state (POMS) six dimensions [<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0126721#pone.0126721.ref012" target="_blank">12</a>] and no significant differences were observed except for confusion, which was significantly higher on D51. <b>Normal range values:</b> Subjective values: Sleepiness was assessed using the Epworth sleepiness scale (ESS), referring to the month prior to the assessment: a score of 10 or more indicated that the subject was sleepy; a score of 16 or more indicated being very sleepy (12). Objective values: in a young and healthy group of subjects normal SOL is under 30 minutes, common total sleep time in adults is around 420 minutes, normal REM latency is above 60 minutes, normal % of REM sleep is above 20% and % of SWS is above 20%. Normal WASO in less than 60 minutes, normal SE is above 90% (Ohayon et al., 2004).</p><p>Subjective and objective sleep variables, sleepiness and mood at D21 and D51.</p

Correlation between objective polysomnographic results and subjective (Buguet and POMS) on D21.

<p>Correlation between objective polysomnographic results and subjective (Buguet and POMS) on D21.</p

The top of the "Fig. 1" shows the 70-day long mission with the 3-day shift schedules to better understand at what point of the mission the polysomnography (PSG) recordings were performed.

<p>The submarine “Téméraire” is also shown schematically with the different levels of lighting in the “work”, “leisure” or “sleep” rooms. The graph at the bottom left of the "Fig. 1" shows the evolution of objective sleep parameters at the two points during the mission. Durations of TST (total sleep time), WASO (Wake after sleep onset), SWS (slow wave sleep), and REM (Rapid Eye movement) sleep did not vary significantly.</p