[Use of regional anesthesia for preoperative analgesia for proximal femoral fractures in the emergency department : A survey on current practice in German-speaking countries and the United Kingdom]. / Anwendung regionalanästhesiologischer Verfahren zur präoperativen Analgesie bei proximalen Femurfrakturen in der Notaufnahme : Eine Umfrage zur Praxis im deutschsprachigen Raum und in Großbritannien.

BACKGROUND: Regional anesthesia (RA) techniques such as femoral nerve block (FNB) or fascia iliaca compartment block (FICB) are effective analgesia techniques in the treatment of pain from proximal femoral fractures (PFF). While in Great Britain (GB) these are already frequently used in the emergency department for preoperative analgesia, in the German-speaking D­A-CH area (Germany, Austria, Switzerland) this seems to occur much less frequently. Therefore, the aim of this study was to survey the type and frequency of RA procedures used and to compare international practice. MATERIAL AND METHODS: In the D­A-CH area as well as in GB, registered emergency departments were contacted and invited to participate in an online survey. The survey included questions on the frequency and type of RA procedures, reasons for non-use, equipment used, person performing the procedure and medications used. RESULTS: The participation rate was 17.4% (142/818 emergency departments). RA procedures for preoperative analgesia in PFF were used in 18.3% (21/115) of hospitals in the D­A-CH region and in 96.3% (26/27) in GB. The most commonly used block was the FICB in GB at 96.2% (25/26) and the FNB in Germany at 66.7% (14/21). In the D­A-CH area, RA procedures are primarily performed by anesthesiology specialists 71.4% (15/21), and in GB by emergency department residents 65.4% (17/26). DISCUSSION: RA procedures are still performed too rarely following PFF in emergency departments in the D­A-CH area. In international comparison with GB there is potential for improvement.

Two-crew operations: stress and fatigue during long-haul night flights.

BACKGROUND: As part of a research program concerning legal aspects of two-pilot operations on long-haul routes, the purpose of the study was to investigate two-crew extended range operations during a flight roster with two consecutive night flights and a short layover. HYPOTHESIS: Present flight time regulations may not be adequate for two-crew minimum operations. METHODS: The study was conducted in cooperation with a German airline company on the route Frankfurt (FRA)-Mahe (SEZ). There were 11 rotations (22 flights) that were investigated by pre-, in- and post-flight data collection each time from the two pilots. Recordings included sleep, taskload, fatigue and stress by measurement of EEG, ECG, motor activity, and subjective ratings. The average actual flight times were 9:15 h (FRA-SEZ) and 9:53 h (SEZ-FRA). All flights took place at night. The layover duration in Mahe was 13:30 h during day-time. RESULTS: During layover, sleep was shortened by 2 h on average compared with 8-h baseline sleep. The two consecutive night duties resulted in a sleep loss of 9.3 h upon return to home base. Inflight ratings of taskload showed moderate grades, but for fatigue ratings an increasing level was observed. Fatigue was more pronounced during the return flight and several pilots scored their fatigue at a critical level. Motor activity, brainwave activity (occurrences of micro-events) and heart rate indicated drowsiness and a low state of vigilance and alertness during both night flights, but these effects were more pronounced during the second flight. CONCLUSIONS: From the findings it is concluded that a duty roster, as conducted in this study, may impose excessive demands on mental and physiological capacity.

Aircrew fatigue in long-haul operations.

The studies were conducted on the transmeridian routes Düsseldorf (DUS)-Atlanta (ATL) and Hamburg (HAM)-Los Angeles (LAX), and on the north-south route Frankfurt (FRA)-Mahe (SEZ). Scheduled flight duration was between 8:50 hours (ATL-DUS) and 11:50 hours (HAM-LAX). In total, 25 rotations (50 flights) have been investigated by pre-, in- and post-flight data collection of sleep, taskload, fatigue and stress by electroencephalogram and electrocardiogram measurements and subjective ratings. Inflight ratings of taskload showed low perceived exertion during the Atlantic flights, and were moderate during the north-south transitions. Fatigue ratings increased with progressing flight duration. Towards the end of long U.S.-westcoast flights performed at day-time, and in all night flights, fatigue was elevated compared to the 'baseline' ratings collected during the day-time DUS-ATL flights. Fatigue was rated as being 'critical' by several pilots, particularly during the return flight SEZ-FRA when fatigue was severely pronounced. From the findings it is concluded that duty schedules, as performed on the route HAM-LAX (because of long duty hours), and particularly on the route FRA-SEZ (because of consecutive night work), may place excessive demands on mental and physiological capacity. With respect to legal aspects, the results are significant and should promote further deliberations for advanced schemes of flight duty time limitations and rest requirements.

Bright light: a countermeasure for jet lag?

After time-zone flights, the environmental time is shifted abruptly. The sleep-wake cycle and the circadian system cannot follow this sudden phase shift. Therefore, some or several days are necessary to achieve complete adjustment to a new time zone. The effects resulting from the displacement between internal and external time are well known as jet lag. In principle, timed bright light is able to enhance the resynchronization process of the circadian system after advance or delay shifts. In this report, the effects of bright light exposure on circadian phases and amplitudes after real or simulated time zone transitions are reviewed from the accessible literature and are critically discussed. It can be concluded that laboratory studies have not been unequivocally successful to support the hypothesis that bright light alleviates jet lag. The sparse number of field studies do not yet allow a clear judgment on the beneficial effect of bright light treatment on jet lag.

[Stress and fatigue in long distance 2-man cockpit crew]. / Stress und Ermüdung im Zwei-Mann-Cockpit auf Langstrecken.

Common rules on flight-duty times and rest requirements within the European Union are under intense discussion. In the deliberations, results from scientific investigations should be considered. As part of a research programme concerning legal aspects of two-pilot operations on long-haul routes, the purpose of the studies was to investigate two-crew extended range operations during transmeridian and transequatorial flight schedules. The studies were conducted with two German charter airlines on the transmeridian routes Düsseldorf (DUS)-Atlanta (ATL) and Hamburg (HAM)-Los Angeles (LAX), and on the north-south route Frankfurt (FRA)-Mahe (SEZ) including two consecutive night flights with a short layover. In total, 25 rotations (50 flights) have been investigated by pre-, in-, and post-flight data collection from the two pilots being the minimum required crew. Recordings included sleep, taskload, fatigue and stress by measurements of EEG, ECG, motor activity and subjective ratings. During the transmeridian schedules, pilots lost one night of sleep because of the return flights which were conducted at night. The resulting sleep deficit was 8.2 h. During the layover of the SEZ-rotation with a duration of 14 h on average, sleep was shortened by 2 h compared with baseline sleep. The two consecutive night flights resulted in a sleep loss of 9.3 h upon return to home base. Inflight ratings of taskload showed low levels during the atlantic flights, and moderate grades during the north-south transitions. Fatigue ratings exhibited an increasing level with progressing flight duration. Towards the end of long US-westcoast flights performed at day-time, and in all night flights, fatigue was enhanced compared to the "baseline" ratings collected during the DUS-ATL flights. Fatigue was scored at a critical level by several pilots, particularly during the return flight SEZ-FRA when fatigue was severely pronounced. The subjective fatigue ratings were confirmed by the objective measurements of motor activity, brain-wave activity (occurrences of micro-sleep) and heart rate which indicated drowsiness and a low state of vigilance and alertness during all night flights under study. From the findings it is concluded that duty schedules, as conducted on the route HAM-LAX (because of long duty hours), and particularly on the route FRA-SEZ, (because of consecutive night duties) are coming close to the limits of mental and physiological capacity. With respect to legal aspects, the results have significance and should promote further deliberations for advanced schemes of flight duty time limitations and rest requirements.

Gastrointestinal problems in airline crew members.

The presence of intestinal and extraintestinal symptoms was investigated by a symptom questionnaire in crew members (n = 190) - and as controls in age and sex matched ground based administrative employees (n = 100) - of a charter carrier and was related to the actual flight schedule of the flying staff during one month. In addition, health and illness behaviors and personal, job and life satisfaction were assessed and related to symptom scores and flight schedules. Flying staff did report significantly more dyspeptic symptoms than did ground staff, and this was found mainly with long-distance flying, since staff with short-haul experience only did not report as much upper intestinal complaints. Also, cabin crew reported significantly more intestinal symptoms than did cockpit members, and part of the upper GI symptoms could be explained by different eating behaviors, specifically more fibre intake in flying staff. With increasing intestinal symptom frequency, doctor visits and sick-days increased, and satisfaction with job and personal life decreased. Flying staff had, however, more awareness of the importance of health behaviors. It is concluded that frequent flying specifically on long distances may result in increased intestinal symptoms, presumably due to time-shift.

Introduction.

NASA: The introduction to a special issue on weightlessness countermeasures provides a brief overview of weightlessness countermeasures and examines the physiology of spaceflight, which includes short- and long-term effects of weightlessness and physiological adaptation.^ieng

Water immersion: analysis of diurnal rhythms of water and electrolyte excretion.

The biorhythmological structure of water-electrolyte metabolism was studied in humans during 7-day "dry" immersion. Results were processed with a set of mathematical methods in order to identify a parameter which would allow to obtain scientifically valid, reliable data without violation of any ethic constraints inherent to investigations with healthy test-subjects. Even this period of immersion gravely impacted functioning of kidney as an executive organ in the system of water-electrolyte homeostasis. Data of this study point to applicability of Cosinor analysis for quantitative assessment of fluctuation patterns in parameters of close to harmonical circadian rhythms, and variation analysis and normalized mean for rhythms of arbitrary forms.

[Therapy of jet lag]. / Therapie des Jet-Lag.

After transmeridian flights, disturbances of the circadian rhythm and sleep occur due to the desynchronization between the body clock and external zeitgebers. Under normal circumstances, these disturbances are not pathological and disappear within a few days. However, they impair well-being and lead to significant changes in performance and vigilance. These effects are of particular importance for tasks and operations which require enhanced attention and alertness. Some of the acute symptoms of jet-lag can be reduced and shortened by appropriate countermeasures. The application of these therapies is practicable and has been successfully incorporated in clinical measures.

Pre-adaptation to shiftwork in space.

Astronauts are often required to work in shift schedules. To test pre-mission adaptation strategies and effects on the circadian system, a study was performed using microgravity simulation by head-down bedrest. Eight male subjects were studied over 4 control days, and 7 days each for pre-mission adaptation, bedrest, and readjustment. The circadian system was assessed by monitoring ECG and temperature, and by collecting urine for determination of hormones and electrolytes. Rhythms did not achieve complete adjustment within the adaptation period when the sleep-wake cycle was shortened by 1 h/day, but resynchronization continued during bedrest. After the bedrest period when the time shift was reversed by a 7-h delay within 2 days, resynchronization was achieved satisfactorily only within 7 days. From the results it is concluded that a sleep-wake cycle advance as used in this study is insufficient to keep the circadian system in pace. Under operational conditions the circadian system of astronauts may become longer and more destabilized than under controlled laboratory conditions.

Response of the circadian system to 6 degrees head-down tilt bed rest.

The influence of simulated microgravity and reduced zeitgebers on the circadian system was examined in eight subjects. The 12-d study included a 3-d period for baseline measurements, 7 d of 6 degrees head-down bed rest, and 2 d for recovery. The sleep-wake cycle was kept constant during the study. The state of the circadian system was assessed from continuous measurements of temperature and ECG, and collections of urine at 3-h intervals for the determination of hormone and electrolyte excretions. Results indicate that only minor changes occurred in rhythm acrophases, whereas daily means for several physiological functions and their circadian amplitudes were significantly altered during the bed-rest phase. These studies using head-down tilt confirm previous findings with horizontal bed rest and indicate that rhythm disturbances can occur without change in the sleep-wake cycle. To the degree that bed-rest studies simulate manned spaceflights, results indicate that variations in circadian cycles can occur even during short-term missions and must be taken into account when interpreting subsequently obtained physiological data.

Sleep patterns in aircrew operating on the polar route between Germany and east Asia.

The study was performed as the second part of an investigation to assess sleep behavior and circadian rhythmicity in aircrew operating regular passenger flights between Germany and East Asia via Anchorage (ANC). Continuous records of sleep and ratings of sleep quality were obtained by sleep logs from 101 B747-cockpit crewmembers, starting at least 3 d before commencing flight duty, continuing during days on duty (the duration depending on the flight schedule) and finishing 4 d after return, at the earliest. Regardless of the specific duty roster, sleep deficit occurred mainly after the first flight leg to ANC, presumably due to the 10-h time zone difference and the short layover time. During the layover in the Far East, the sleep deficit diminished partly because of additional naps. Sleep was often disturbed and scattered over days and nights. Another pronounced sleep deficit occurred after the first return flight from South Korea or Japan to ANC. Compared to the outgoing layover period in ANC, the number and duration of naps increased during this layover and, additionally, on the first 2 d after returning home. Poorer sleep quality ratings were associated with accumulated sleep deficit and increased napping, but significant decrements in sleep quality were seen only during two out of the six different duty rosters. All six of the polar route duty rosters may lead to significant sleep disturbances. During some flight schedules the sleep deficit is large enough to raise operational implications.

Influence of melatonin treatment on human circadian rhythmicity before and after a simulated 9-hr time shift.

The hormone melatonin is currently proposed by some investigators to be an efficient means for decreasing the impairing effects of jet lag. Eight healthy male subjects, aged 20 to 32, underwent a 9-hr advance shift in the isolation facility of our institute during two periods each of 15 days' duration. In a double-blind, crossover design, subjects took either melatonin or placebo at 1800 hr local time for 3 days before the time shift and at 1400 hr for 4 days afterwards. The time shift was simulated on days 7 and 8 by shortening the sleep period by 6 hr and the following wake period by 3 hr. Body temperature was recorded every 90 min, and urine was collected at 3-hr intervals all day and night. Melatonin treatment enhanced the resynchronization speed of some, but not all, hormone and electrolyte excretion rates for several days after the time shift. The adaptation speed of the temperature rhythm significantly increased during one postshift day. In addition, the circadian temperature rhythm had a significantly higher amplitude under melatonin treatment than under placebo after the time displacement. For the placebo group, the rhythm of 6-hydroxymelatoninsulfate excretion exhibited an advance shift in five subjects, whereas the other three showed a delay shift, and adjustment did not achieve more than one-half of the expected value within 8 days. A significantly different adjustment could be observed in the melatonin-treated group: Seven subjects underwent an advance shift of the expected 9 hr within an average of 8 days. The results suggest that melatonin treatment can accelerate resynchronization of the melatonin excretion rhythm after eastward time zone transitions. The improvement is not, however, sufficiently great that we can recommend melatonin for the alleviation of jet lag.