A critical review of the psychophysiology of driver fatigue.

Clinicians, especially physicians in training, often work long hours and get inadequate sleep. The implications of fatigue among clinicians for the quality of medical care have not been adequately studied, but sleep deprivation is likely to cause medical errors. This article reviews the effect of fatigue on performance, as well as current policies regulating residents' hours of work and options for new regulations governing residency shifts. The authors argue that reform is needed because the long work hours of clinicians adversely affect the quality of health care.

Fatigue among Clinicians and the Safety of Patients

Use of sleep hygiene in the treatment of insomnia.

https://www.sleep.theclinics.com/article/S1556-407X(09)00035-6/pdf

Sleep Loss and Fatigue in Shift Work and Shift Work Disorder.

Medical residents in hospitals are often required to be on duty for long hours. In 2003 the organization overseeing graduate medical education adopted common program requirements to restrict resident workweeks, including limits to an average of 80 hours over 4 weeks and the longest consecutive period of work to 30 hours in order to protect patients and residents from unsafe conditions resulting from excessive fatigue.Resident Duty Hours provides a timely examination of how those requirements were implemented and their impact on safety, education, and the training institutions. An in-depth review of the evidence on sleep and human performance indicated a need to increase opportunities for sleep during residency training to prevent acute and chronic sleep deprivation and minimize the risk of fatigue-related errors. In addition to recommending opportunities for on-duty sleep during long duty periods and breaks for sleep of appropriate lengths between work periods, the committee also recommends enhancements of supervision, appropriate workload, and changes in the work environment to improve conditions for safety and learning.All residents, medical educators, those involved with academic training institutions, specialty societies, professional groups, and consumer/patient safety organizations will find this book useful to advocate for an improved culture of safety.

Resident Duty Hours: Enhancing Sleep, Supervision, and Safety

Managing fatigue in complex operational settings requires attention to multiple factors, including hours of service, scheduling, education and training, counter-measures, technology, and research. Alertness-management strategies can be used to promote safety, performance, and productivity in operational settings. These strategies can involve both preventive (used prior to duty/shift) and operational (used during duty/shift) approaches. Studies have demonstrated the effectiveness of naps to improve subsequent performance and alertness. Strategic naps can be used effectively to promote performance and alertness in operational settings. Two potential negative effects of naps, sleep inertia and effects on subsequent sleep periods, are discussed. Sleep inertia can involve sleepiness and decreased performance immediately upon awakening from a nap. It should be a consideration prior to implementing nap strategies in work environments. A study of planned rest periods in long-haul flight operations demonstrated the effectiveness of in-flight naps to promote performance and alertness during subsequent critical phases of flight (descent and landing). Empirical evaluation of alertness-management strategies during regular operations will be critical to their implementation. Combining strategies may be the most effective approach to managing fatigue engendered by 24-h operational demands. Other considerations prior to implementing alertness-management strategies in operational environments are discussed.

https://onlinelibrary.wiley.com/doi/pdf/10.1111/j.1365-2869.1995.tb00229.x

Alertness management: strategic naps in operational settings.

The need for 24-h operations creates nonstandard and altered work schedules that can lead to cumulative sleep loss and circadian disruption. These factors can lead to fatigue and sleepiness and affect performance and productivity on the job. The approach, research, and results of the NASA Ames Fatigue Countermeasures Program are described to illustrate one attempt to address these issues in the aviation environment. The scientific and operational relevance of these factors is discussed, and provocative issues for future research are presented.

Fatigue in operational settings: examples from the aviation environment.

Progress made in joint NASA/Army research concerning rotorcraft flight-dynamics modeling, design methodologies for rotorcraft flight-control laws, and rotorcraft parameter identification is reviewed. Research into these interactive disciplines is needed to develop the analytical tools necessary to conduct flying qualities investigations using both the ground-based and in-flight simulators, and to permit an efficient means of performing flight test evaluation of rotorcraft flying qualities for specification compliance. The need for the research is particularly acute for rotorcraft because of their mathematical complexity, high order dynamic characteristics, and demanding mission requirements. The research in rotorcraft flight-dynamics modeling is pursued along two general directions: generic nonlinear models and nonlinear models for specific rotorcraft. In addition, linear models are generated that extend their utilization from 1-g flight to high-g maneuvers and expand their frequency range of validity for the design analysis of high-gain flight control systems. A variety of methods ranging from classical frequency-domain approaches to modern time-domain control methodology that are used in the design of rotorcraft flight control laws is reviewed. Also reviewed is a study conducted to investigate the design details associated with high-gain, digital flight control systems for combat rotorcraft. Parameter identification techniques developed for rotorcraft applications are reviewed.

Helicopter mathematical models and control law development for handling qualities research

A ground simulation experiment was conducted on a flight simulator for advanced aircraft to investigate the influence and interaction of flight-control system, flight-director display, and crew-loading situation on helicopter flying qualities during terminal-area operations in instrument conditions. Six levels of control complexity were implemented on a representative helicopter model. The six levels of augmentation were examined with display variations consisting of raw elevation and azimuth data only and of raw data plus one-, two-, and three-cue flight directors. Crew-loading situations simulated for the control-display combinations were dual-pilot operation and single-pilot operation. Four pilots performed a total of 150 evaluations of combinations of these parameters for a representative microwave landing system approach task. Pilot rating results indicated the existence of a control display trade-off for ratings of satisfactory, whereas ratings of adequate-but-unsatisfactory depended primarily on the control system; the control system required for ratings of adequate-but-unsatisfactory was clearly more complex for the single-pilot situation than that for the dual-pilot situation.

Investigation of Control, Display, and Crew-Loading Requirements for Helicopter Instrument Approach

Flight operations can engender fatigue, which can affect flight crew performance, vigilance, and mood. The National Transportation Safety Board (NTSB) requested the NASA Fatigue Countermeasures Program to analyze crew fatigue factors in an aviation accident that occurred at Guantanamo Bay, Cuba. There are specific fatigue factors that can be considered in such investigations: cumulative sleep loss, continuous hours of wakefulness prior to the incident or accident, and the time of day at which the accident occurred. Data from the NTSB Human Performance Investigator's Factual Report, the Operations Group Chairman's Factual Report, and the Flight 808 Crew Statements were analyzed, using conservative estimates and averages to reconcile discrepancies among the sources. Analysis of these data determined the following: the entire crew displayed cumulative sleep loss, operated during an extended period of continuous wakefulness, and obtained sleep at times in opposition to the circadian disposition for sleep, and that the accident occurred in the afternoon window of physiological sleepiness. In addition to these findings, evidence that fatigue affected performance was suggested by the cockpit voice recorder (CVR) transcript as well as in the captain's testimony. Examples from the CVR showed degraded decision-making skills, fixation, and slowed responses, all of which can be affected by fatigue; also, the captain testified to feeling "lethargic and indifferent" just prior to the accident. Therefore, the sleep/wake history data supports the hypothesis that fatigue was a factor that affected crewmembers' performance. Furthermore, the examples from the CVR and the captain's testimony support the hypothesis that the fatigue had an impact on specific actions involved in the occurrence of the accident.

J. Victor Lebacqz

Papers

Alertness management: strategic naps in operational settings.

Fatigue in operational settings: examples from the aviation environment.

Helicopter mathematical models and control law development for handling qualities research

Investigation of Control, Display, and Crew-Loading Requirements for Helicopter Instrument Approach

Analysis of Crew Fatigue in AIA Guantanamo Bay Aviation Accident