Human Factors and Air Operations in the South Atlantic Campaign: Discussion Paper

Promoting sleep in shiftworkers and intercontinental travelers

A number of techniques and treatments can be used to alleviate the sleep disturbance associated with both shiftwork and transmeridian travel. Optimization of the sleeping environment and avoidance of substances such as caffeine and alcohol before sleep are the best initial approach. Timing sleep to coincide with some of the normal sleep period where possible will improve sleep quality in shiftworkers. Similarly, following transmeridian flight, restricting sleep to the nocturnal period in the new time zone will assist adaptation. Hypnotic drugs may be of benefit to alleviate sleep disturbance experienced by shiftworkers or transmeridian travelers. Selection of the most appropriate medication must take into account required duration of action and possible residual effects of the drug on alertness. Hypnotics may be useful, particularly in middle-aged individuals who already have disturbed sleep, on those occasions when poor sleep is anticipated, for example following an eastward flight or after the initial change to night duty. Over-the-counter preparations should be avoided whenever possible unless it is known that they are not associated with residual sequelae.

Modafinil, d-amphetamine and placebo during 64 hours of sustained mental work. II. Effects on two nights of recovery sleep

Polysomnograms were obtained from 37 volunteers, before (baseline) and after (two consecutive recovery nights) a 64-h sleep deprivation, with (d-amphetamine or modafinil) or without (placebo) alerting substances. The drugs were administered at 23.00 hours during the first sleep deprivation night (after 17.5 h of wakefulness), to determine whether decrements in cognitive performance would be prevented; at 05.30 hours during the second night of sleep deprivation (after 47.5 h of wakefulness), to see whether performance would be restored; and at 15.30 hours during the third day of continuous work, to study effects on recovery sleep. The second recovery night served to verify whether drug-induced sleep disturbances on the first recovery night would carry over to a second night of sleep. Recovery sleep for the placebo group was as expected: the debt in slow-wave sleep (SWS) and REM sleep was paid back during the first recovery night, the rebound in SWS occurring mainly during the first half of the night, and that of REM sleep being distributed evenly across REM sleep episodes. Recovery sleep for the amphetamine group was also consistent with previously published work: increased sleep latency and intrasleep wakefulness, decreased total sleep time and sleep efficiency, alterations in stage shifts, Stage 1, Stage 2 and SWS, and decreased REM sleep with a longer REM sleep latency. For this group, REM sleep rebound was observed only during the second recovery night. Results for the modafinil group exhibited decreased time in bed and sleep period time, suggesting a reduced requirement for recovery sleep than for the other two groups. This group showed fewer disturbances during the first recovery night than the amphetamine group. In particular, there was no REM sleep deficit, with longer REM sleep episodes and a shorter REM latency, and the REM sleep rebound was limited to the first REM sleep episode. The difference with the amphetamine group was also marked by less NREM sleep and Stage 2 and more SWS episodes. No REM sleep rebound occurred during the second recovery night, which barely differed from placebo. Hence, modafinil allowed for sleep to occur, displayed sleep patterns close to that of the placebo group, and decreased the need for a long recovery sleep usually taken to compensate for the lost sleep due to total sleep deprivation.

Aeromedical transfer of burned patients: a review with special reference to European civilian practice

Inter-hospital transfer of a patient with a burn injury can usually be undertaken with confidence, even for non-medical reasons, as long as it is undertaken with care. Transfer by air has many advantages for the seriously burned patient provided that all potential risk factors are taken into account. There is a need to consider infection, the respiratory condition and the cardiovascular status of the patient. The possibility of other injuries should also be borne in mind. Early transfer requires careful but urgent planning if it is to be achieved, as is desirable, by days 3 or 4 postburn. Transfer during or at the end of the resuscitation phase, or in the convalescent phase when skin cover is well established, poses least problems. Plenty of sterile paraffin gauze, wool and crêpe bandages will be needed. Appropriate monitoring equipment and full cardiovascular and respiratory resuscitation facilities should be carried. Care should be taken in the selection of the medical and nursing personnel to accompany the patient, who should whenever possible have experience of burns as well as aviation medicine.

Human orthostatic reflexes after taking temazepam at night

1. Cardiovascular orthostatic reflexes have been studied at night in 12 healthy male subjects who were given two soft gelatin capsules each containing 0 or 10 mg temazepam at 21.30 h. 2. The changes in heart rate, blood pressure and forearm blood flow on consecutive 5 min exposures to lower body negative pressure (suction) at 30, 40 and 50 mm Hg were measured before and then 1.5 and 9.5 h after giving doses of 10 or 20 mg temazepam in a placebo-controlled double-blind cross-over study. 3. Pre-suction resting values were not affected by temazepam, but 1.5 h after giving the capsules there were significant differences in the responses to suction between the placebo and 20 mg temazepam experiments: the tachycardia after 20 mg temazepam was about one-third greater and the forearm vasoconstriction was about 50% less. The effect of the 10 mg dose was equivocal. No residual effects were detected the next morning. 4. These alterations in orthostatic reflexes soon after the administration of temazepam at night did not impair the maintenance of arterial blood pressure in these healthy subjects.