“When I was a resident” is a phrase used many times by attending anesthesiologists as a prelude to a teachable moment. In an effort to avoid overused clichés, many have tried to remove such banalities from their educational repertoires. Despite this, one may find themselves initiating thoughts with exactly those sentiments, especially when considering the contrast in work-hour requirements for residents today compared to those in the past. Although generational differences exist regarding work ethics, the implementation in 2003 by the Accreditation Council on Graduate Medical Education (ACGME) of duty-hour restrictions represents a transition to a new era of residency training in the United States differentiating the modern-day trainee from those who trained before. The ACGME heralded this implementation as the start of an era of higher quality care when they established a maximum 80-hour work week averaged over a 4-week period. Recently, the ACGME revised section VI of the Common Program Requirements that became effective on July 1, 2017. This document defines total work-week hour limitations, with in-house night float mentioned within the context of these limitations, as well as the number of continuous hours a trainee can be scheduled for duties. Education about sleep deprivation and sleep health is now mandatory for all residents enrolled in an ACGME-accredited training program. In an effort to maintain duty-hour compliance, many residency training programs have instituted night-float systems designed to reduce the number of hours that residents are assigned to work consecutively and, presumably, alleviate some of the sleep deprivation that results from on-call activities.
These duty-hour requirements were aimed at promoting patient safety and resident wellness. Resident wellness is now a contemporary buzzword emphasized across all residency training programs intending to represent the overall physical, mental, and emotional health of trainees. The qualitative metrics to evaluate resident wellness were previously based largely on survey data1 that contained inherent bias.
Recently, however, resident wellness literature has increasingly used scientific data analysis to improve how we understand the impact of interventions on resident wellness. In this issue of Anesthesia & Analgesia, Wang et al2 explore how anticipation of resident night call may influence parasympathetic activity, using heart rate variability (HRV) as an indicator. Obtained by computer analysis of electrocardiogram data, HRV provides information about human physiologic sympathetic and/or parasympathetic fluctuations3; these fluctuations have been associated with chronic health conditions including hypertension, diabetes, and heart failure.4
HRV also correlates with perceived increases in job strain.5 With this in mind, Wang et al2 prospectively studied 8 anesthesia residents by measuring HRV on the mornings of a regular work day and before and after a night duty work day (defined by a regular work day coupled with an in-house night shift contiguously). Their findings suggested that HRV on the morning of an anticipated night shift was indicative of depression of parasympathetic activity, which, as previously mentioned, may be an indication of stress. That this finding occurs at the start of a night duty work day indicated to the researchers that these participants might have been experiencing stress due to anticipation of the night duty day to come. There was no change in HRV the morning after a night shift compared to baseline. This may be surprising to some because, presumably, this would be the time when the stress of sleep deprivation would manifest. However, previous research demonstrates that sleep deprivation does not change HRV in healthy adult males,6 which is consistent with the findings in this study.
However, the study did have some significant weaknesses. As stated, the sampling was very low, which presented some statistical challenges for the researchers. These were addressed in the article but must be considered as problematic and requiring of a more thorough investigation. In addition, the specific stress anticipation that residents were responding to is difficult to determine. The researchers made many assumptions in this regard, citing case acuity and lack of resources, but this association may have been due to a great many things not accounted for in the study design.
The residents in Wang et al2 had a rotating night call system requiring in-hospital, on-duty activity for 24 hours at a time. Interestingly, the residents were allowed a 3-hour break during the daytime hours to mitigate the possible effects of fatigue during the nighttime hours. One possible explanation for the anticipation stress that they experienced could be the length of the shift. One study demonstrated that conversion from 24-hour shifts to 16-hour shifts positively affected residents’ perception of their own wellness.7 In this prospective survey study, residents reported improved quality of life and overall less fatigue when shifts were shortened. Many programs have moved toward a resident night-float coverage model in their attempt to improve resident quality of life, thus promoting resident wellness. Night-float duty with fewer hours than a 24-hour shift and several consecutive nights may allow for less sleep deprivation, which would also improve patient safety by improving reaction time and creating less avoidance behaviors.8
As scientific data become more available, it is essential to consider how these data may be applied to impact resident training and wellness. There will always be certain health care specialties that are required 24 hours a day and, thus, must provide services during nighttime as well as daylight hours; presumably, those choosing the field of anesthesiology possess that knowledge. Thus, choosing the specialty of anesthesiology entails an active choice to participate in nighttime clinical activity. Curtailing nighttime responsibilities by instituting night-shift work to optimize resident wellness might create expectations that do not represent anesthesiology attending on-call models in the United States. Furthermore, after-hours exposure, which includes nighttime duty, is an important part of training and provides additional opportunity to have adequate experience with cases that present as emergencies with high acuity. Having to make decisions under these circumstances, perhaps during a long shift, may help prepare residents for situations that will be encountered after training.
Is night float the best solution? Evidence demonstrating the deleterious effects of night-shift work on health is mounting. A link has been established between night-shift duty load for physicians and increased blood pressure along with other sympathetic nervous system imbalances.9 The number of nights shifts worked consecutively may also affect cortisol and melatonin levels.10 As one might expect, night-shift work has been associated with higher burnout rates and minor mental disorders even in people who work outside of the medical field.11 It is difficult to quantify just how much these factors contribute to long-term health problems, and further research is clearly still needed.
What is known is that there are higher rates of depression and suicide among residents across all specialties compared to the rest of the population. One report showed that 28% of residents experience a major depressive episode during training versus 7%–8% in a comparably aged group in the general population.12 This coincides with a higher suicide rate compared to the general population with a relative risk in male physicians of 1.41 and female physicians 2.27.13 Anesthesiologists are included in the group of medical specialties that are most likely to experience substance abuse problems.14 Due to the stigma associated with depression, physicians as a group tend not to seek help when experiencing feelings of depression or suicidal ideology. This makes it difficult for colleagues or program directors to identify those residents who may experience suicidal ideation. How trainee duty hours and nighttime duty hours might impact these figures warrants further investigation.
The authors should be applauded for continuing to add to the increasing awareness regarding night shift and its potentially detrimental effects on health. Although the literature is becoming more extensive on the importance of this problem, a paucity of information is available for finding a plausible solution. Should night coverage be eliminated from training curriculums all together? This seems extreme and likely will not provide appropriate preparation for the trainee. Furthermore, it may not be feasible without hiring others to fulfill nighttime duties. If night shift must remain a part of resident training, how can it be optimized to give the greatest educational value while reducing the detrimental effects on health? One possible answer may be a protected 3-hour sleep time during the night shift, which was used in Wang et al2 and has been shown to improve sleep during call and reduce periods of prolonged wakefulness.15 Regardless of whether it is required nap time, a reduction in hours, or a change in duty-hour formatting (eg, night float), efforts must continue toward improvement of resident wellness. This is essential not only for the health of residents but also for the health of all physicians in the future.
Name: Sean Kiley, MD.
Contribution: This author helped write the manuscript.
Name: Brenda G. Fahy, MD, FCCP, MCCM.
Contribution: This author helped write the manuscript.
This manuscript was handled by: Edward C. Nemergut, MD.
1. Ahmed N, Devitt KS, Keshet I, et al. A systematic review of the effects of resident duty hour restrictions in surgery: impact on resident wellness, training, and patient outcomes. Ann Surg. 2014;259:1041–1053.
2. Wang M.-L., Lin P.-L., Huang C.-H., Huang H.-H. Decreased parasympathetic activity of heart rate variability during anticipation of night duty in anesthesiology residents. Anesth Analg. 2018;126:1013–1018.
3. Allen AR, Gullixson LR, Wolhart SC, Kost SL, Schroeder DR, Eisenach JH. Dietary sodium influences the effect of mental stress on heart rate variability: a randomized trial in healthy adults. J Hypertens. 2014;32:374–382.
4. Xhyheri B, Manfrini O, Mazzolini M, Pizzi C, Bugiardini R. Heart rate variability today. Prog Cardiovasc Dis. 2012;55:321–331.
5. Hernández-Gaytan SI, Rothenberg SJ, Landsbergis P, et al. Job strain and heart rate variability in resident physicians within a general hospital. Am J Ind Med. 2013;56:38–48.
6. Quintana DS, Elvsåshagen T, Zak N, et al. Diurnal variation and twenty-four hour sleep deprivation do not alter supine heart rate variability in healthy male young adults. PLoS One. 2017;12:e0170921.
7. Sussman D, Paul JE. The impact of transitioning from a 24-hour to a 16-hour call model amongst a cohort of Canadian anesthesia residents at McMaster University—a survey study. Adv Med Educ Pract. 2015;6:501–506.
8. Saadat H, Bissonnette B, Tumin D, et al. Effects of partial sleep deprivation on reaction time in anesthesiologists. Paediatr Anaesth. 2017;27:358–362.
9. Lee HH, Lo SH, Chen BY, et al. Increased night duty loading of physicians caused elevated blood pressure and sympathetic tones in a dose-dependent manner. Int Arch Occup Environ Health. 2016;89:413–423.
10. Jensen MA, Garde AH, Kristiansen J, Nabe-Nielsen K, Hansen ÅM. The effect of the number of consecutive night shifts on diurnal rhythms in cortisol, melatonin and heart rate variability (HRV): a systematic review of field studies. Int Arch Occup Environ Health. 2016;89:531–545.
11. Cheng WJ, Cheng Y. Night shift and rotating shift in association with sleep problems, burnout and minor mental disorder in male and female employees. Occup Environ Med. 2017;74:483–488.
12. Mata DA, Ramos MA, Bansal N, et al. Prevalence of depression and depressive symptoms among resident physicians: a systematic review and meta-analysis. JAMA. 2015;314:2373–2383.
13. Schernhammer ES, Colditz GA. Suicide rates among physicians: a quantitative and gender assessment (meta-analysis). Am J Psychiatry. 2004;161:2295–2302.
14. Hughes PH, Conard SE, Baldwin DC Jr, Storr CL, Sheehan DV. Resident physician substance use in the United States. JAMA. 1991;265:2069–2073.
15. Shea JA, Dinges DF, Small DS, et al. A randomized trial of a three-hour protected nap period in a medicine training program: sleep, alertness, and patient outcomes. Acad Med. 2014;89:452–459.