Variabilidad de la frecuencia cardíaca Validez de grabaciones ultra cortas de índices de balance autonómico de sujetos en reposo / Heart rate variability Validity of ultra-short recordings of autonomic balance indices of subjects at rest

Objetivo: hallar los tiempos mínimos de registro de variabilidad de la frecuencia cardíaca (VFC) de plazo-ultra-corto, menor a 5min, para que los índices extraídos del diagrama de Poincaré, SS y S/PS, indicadores del balance autonómico puedan ser equivalentes a los obtenidos mediante VFC de corto-plazo (5min). Método: el estudio incluyó un grupo de 23 sujetos. Las series RR, extraídas de la señal del electrocardiograma, fueron registradas durante 300s en reposo y se obtuvieron series de 60s, 90s, 120s y 240s. Los índices de VFC se calcularon para cada serie y fueron comparados con el índice correspondiente de la serie de 300s, empleando diferentes métodos de análisis de concordancia, correlación de Pearson, Bland y Altman y Delta de Cohen. Resultados: los índices SS en registros de duración mínima de 120s mostraron ser equivalentes a los de VFC de corto-plazo y ln(S/PS) de 90s. Conclusiones: se obtuvieron índices de VFC de plazo-ultra-corto equivalentes a los obtenidos para análisis de VFC de corto-plazo. Esta reducción en los tiempos de medición permitirá ampliar el empleo de la VFC para el monitoreo del estado de salud y bienestar de las personas, y ayudando a que los preparadores físicos logren un mejor rendimiento en el registro y procesamiento de la información obtenida. Los resultados hallados motivan la realización de nuevos estudios para analizar el comportamiento de estos indicadores en diferentes poblaciones y con el empleo de distintos métodos de pre-procesamiento de las series RR. (AU)

"Multivariate analysis of the impact of sleep and working hours on medical errors: a MICE approach".

BACKGROUND: The main objective of this study was to describe the relationship between working conditions, sleep and psycho-affective variables and medical errors. METHODS: This was an observational, analytical and cross-sectional study in which 661 medical residents answered questionnaires about working conditions, sleep and psycho-affective variables. Actigraphic sleep parameters and peripheral temperature circadian rhythm were measured in a subgroup of 38 subjects. Bivariate and multivariate predictors of medical errors were assessed. RESULTS: Medical residents reported working 66.2 ± 21.9 weekly hours. The longest continuous shift was of 28.4 ± 10.9 h. They reported sleeping 6.1 ± 1.6 h per day, with a sleep debt of 94 ± 129 min in workdays. A high percentage of them reported symptoms related to psycho-affective disorders. The longest continuous shift duration (OR = 1.03 [95% CI, 1.00-1.05], p = 0.01), working more than six monthly on-call shifts (OR = 1.87 [95% CI, 1.16-3.02], p = 0.01) and sleeping less than six hours per working day (OR = 1.66 [95% CI, 1.10-2.51], p = 0.02) were independently associated with self-reported medical errors. The report of medical errors was associated with an increase in the percentage of diurnal sleep (2.2% [95% CI, 0.1-4.3] vs 14.5% [95% CI, 5.9-23.0]; p = 0.01) in the actigraphic recording. CONCLUSIONS: Medical residents have a high working hour load that affect their sleep opportunities, circadian rhythms and psycho-affective health, which are also related to the report of medical errors. These results highlight the importance of implementing multidimensional strategies to improve medical trainees' sleep and wellbeing, increasing in turn their own and patients' safety.

Sleep misalignment and circadian rhythm impairment in long-haul bus drivers under a two-up operations system.

OBJECTIVES: The objective of the study was to describe working and sleep conditions and to assess how sleep opportunities are associated with obtained sleep and alertness, in a sample of long-haul bus drivers working with a two-up operations system. METHODS: Measures of subjective sleep and sleepiness, actigraphy, circadian temperature rhythm, and psychomotor vigilance tasks were obtained from a sample of 122 drivers from Argentina. Variables were compared between high and low fatigue risk groups, which were formed using a median split of a fatigue risk score. The score was calculated based on drivers' total working hours, maximum shift duration, minimum short break duration, maximum night work per seven days, and long break frequencies. RESULTS: Considering a standardized one-day period, sleep in the bus accounted for 1.9±0.1 h of total sleep (57±1% efficiency), sleep at destination for 1.6±0.2 h of total sleep (90±1% efficiency), and sleep at home for 3.8±0.2 h of total sleep (89±1% nap efficiency and 90±1% anchor sleep efficiency). In drivers exposed to high-risk working schedules, the circadian temperature rhythm was weaker (lower % of variance explained by the model) (22.0±1.7% vs. 27.6±2.0%, p <0.05) and without a significant acrophase. CONCLUSIONS: Drivers obtained a total amount of weekly sleep similar to the recommended levels for adults, but distributed at different locations and at different times during the day. High-risk working schedules were associated with disruption of circadian temperature rhythms. These results point out to the need of the implementation of shift-work scheduling strategies to minimize sleep misalignment and circadian desynchronization in long-haul bus drivers.

Hours of service regulations for professional drivers in continental Latin America.

OBJECTIVES: To describe the hours of service provisions in continental Latin America. DESIGN: Information on regulations of service hours was extracted from either the national transportation authorities or ministries of transportation (or the equivalent institution) from each country. SETTING: Seventeen sovereign countries in continental Latin America (Argentina, Bolivia, Brazil, Chile, Colombia, Costa Rica, Ecuador, El Salvador, Guatemala, Honduras, Mexico, Nicaragua, Panama, Paraguay, Peru, Uruguay, Venezuela). PARTICIPANTS: N/A INTERVENTION (IF ANY): N/A MEASUREMENT: Data on (a) limit on work hours, (b) mandatory daily time off (or rest), (c) overall schedule (mandatory weekly time off), and (d) daily breaks were extracted and summarized. RESULTS: Of the 17 countries surveyed, 9 countries have provisions limiting the daily amount of hours of service for professional drivers. Ten have provisions for mandatory daily rest, but only 5 have explicit provisions limiting the number of continuous working days, with mandatory uninterrupted time off >35 hours. Eight countries have provisions for mandatory breaks that limit the hours of continuous driving (ranging from 3 to 5:30 hours). CONCLUSION: Regulations that govern a population with 6 million injuries and over 100,000 deaths per year due to motor vehicle accidents leave important gaps. A minority, 6, of the countries regulated all 3 aspects; daily hours, breaks, and time off, and 3 regulate none of these. The regulations are less precise and restrictive than those in high-income countries, despite the doubled road injury mortality, and likely expose professional drivers and other road users to an increased risk of fatigue-related accidents.

La actigrafía como herramienta diagnóstica / ROLE OF ACTIGRAPHY IN THE STUDY OF SLEEP AND CIRCADIAN RHYTHMS : ACCURACY, SENSITIVITY AND SPECIFICITY OF ACTIGRAPHY FOR THE ASSESSMENT OF SLEEP DISORDERS

El diagnóstico y tratamiento de los trastornos de sueño, especialmente los asociados al Ritmo Circadiano, utilizan métodos costosos, invasivos e incómodos tanto para los pacientes como para los médicos, quienes deben realizar un seguimiento de los hábitos de sueño. La actigrafía ha sido aceptada como una herramienta válida para el estudio y diagnóstico de trastornos circadianos. Más de 300 dispositivos se comercializan actualmente para el uso personal, pero pocos de estos han sido probados para un uso diagnóstico. En este estudio comparativo compuesto por 21 sujetos, se informa acerca de los patrones de sueño y actividad registrados por algunos dispositivos, como Micro-Mini Motionlogger Watch, Condor Act Trust, MisFit Flash y Fitbit Flex. No se observan diferencias significativas en el análisis del patrón de actividad de descanso entre dispositivos. Tampoco se observan para el sueño Onset (inicio), el Tiempo Total de Sueño y la Eficiencia del Sueño. Según el tipo de estudio y análisis deseado, éstos dispositivos pueden resultar alternativos para los registros de actividad y sueño.

This is a comparative analysis of actigraphy performance in comparison with different sleep Parameters. Actigraphy is a non-invasive and valid method of monitoring human rest activity cycles. The report describes the role of actigraphy to assess the study of sleep-wake patterns and circadian rhythms, evaluating its development as a diagnostic tool, with a comparative analysis of actigraphy performance in comparison with different sleep parameters. The diagnosis and treatment of sleep disorders, especially those associated with the cicardian rhythm, employ very expensive costs, invasives or unconfortable for the patients the same as for physicians, who must perform a demand of the sleeping habits. The International Classification of Sleep Disorders has identified more than 80 sleep disorders, all of them have associated treatments. Actinography has been accepted as a valid tool for the study and diagnosis of circadian disorders. All these aspects are discussed in the article

Comparative analysis of actigraphy performance in healthy young subjects.

Sleep-related health disorders are increasing worldwide; diagnosis and treatment of such sleep diseases are commonly invasive and sometimes unpractical or expensive. Actigraphy has been recently introduced as a tool for the study of sleep and circadian disorders; however, there are several devices that claim to be useful for research and have not been thoroughly tested. This comparative study provides activity, sleep and temperature information regarding several of the most commonly used actigraphers: Micro-Mini Motion Logger; Act Trust; Misfit Flash; Fitbit Flex & Thermochron. Twenty-two healthy young subjects were assessed with five different commercial actigraphs (Micro-Mini Motionlogger Watch, Condor Act Trust, MisFit Flash and Fitbit Flex) and a temperature recorder (Thermochron), and also completed a sleep diary for a week. There were not significant differences in the analysis of rest-activity pattern between devices. Temperature rhythm comparison between the Act Trust and the Thermochron showed significant differences in rhythm percentage (p<0.05) and mesor (p<0.0563) but not in amplitude or acrophase. Although data accessibility and ease of use was very different for the diverse devices, there were no significant differences for sleep onset, total sleep time and sleep efficiency recordings, where applicable. In conclusion, depending on the type of study and analysis desired (as well as cost and compliance of use), we propose some relative advantages for the different actigraphy/temperature recording devices.