Stress load of emergency service: effects on the CAR and HRV of HEMS emergency physicians on different working days (N = 20)
The occupation of the emergency physicians (EPs) of helicopter emergency medical services (HEMS) can be characterized as a high-strain occupation (Karasek in Adm Sci Q 24(2):285–308. https://doi.org/10.2307/2392498, 1979). Therefore, the aim of this study was to measure and compare the stress load of the EPs of HEMS on duty on air ambulance workdays and on 2 control days.
In this field study (within-subjects design), hormonal, physiological, and self-perceived stress levels of 20 EPs [3 females, 17 males; mean age (M) = 44.95 years, SD = 4.80, 95% confidence interval (CI) (42.71, 47.19)] of HEMS, were recorded on different test days. Measurements of the cortisol awakening response (CAR) and the heart rate variability (HRV) were performed while on duty on the air ambulance and during workdays at the outpatient clinic as well as at home on days of rest.
There were significant differences in the CAR (area under the curve with respect to ground F(2,38) = 12.81, p < 0.001) between the 3 test days with the highest values on the workday at the outpatient clinic [M = 81.24; 98.75% CI (61.24, 101.24)] and not on the air ambulance day [M = 61.82; 98.75% CI (45.18, 78.46)] or on the day of rest [M = 52.96; 98.75% CI (38.17, 67.76)]. In addition, the HRV parameter SDNN [F(2,38) = 6.369; p = 0.004] presented significant differences between the 3 test days with lower levels on the day at the outpatient clinic [M = 101.44; 98.75% CI (83.50, 119.38)] in contrast to the air ambulance day [M = 120.16; 98.75% CI (100.02, 140.30)] and to the resting day [M = 123.79; 98.75% CI (106.49, 141.10)]. Furthermore, there were significant differences in the HRV parameter LF/HF [F(2,38) = 6.215; p = 0.005] between the 3 testing days with the highest values on the workday at the outpatient clinic [M = 8.69; 98.75% CI (6.29, 11.09)] compared to the air ambulance day [M = 6.54; 98.75% CI (4.50, 8.57)] and the day of rest [M = 6.43; 98.75% CI (4.57, 8.29)].
Compared with the standard values and previous studies, EPs of HEMS have an increase in hormonal reactivity in the morning and a lack of recovery of the ANS. It can be concluded that—with respect to the psychobiological stress model by McEwen and Lasley (The end of stress as we know it, National Academic Press, Washington, 2003)—work-related stressors persist too long or the stress response is exaggerated (allostatic load) due to chronic stress induction and lack of recovery.
KeywordsStress load Cortisol awakening response (CAR) Heart rate variability (HRV) Emergency physicians (EPs) Helicopter emergency medical services (HEMS)
Autonomic nervous system
Area under the curve
Area under the curve with respect to ground
Area under the curve with respect to increase
Cortisol awakening response
The European Society of Cardiology
Helicopter emergency medical services
Power in high-frequency range 0.15–0.4 Hz
Heart rate variability
Power in low-frequency range 0.04–0.15 Hz
The North American Society of Pacing and Electrophysiology
International Society of Psycho-neuroendocrinology
Primary appraisal secondary appraisal
Root-mean-square successive differences
Standard deviation of all NN intervals
Trier Inventory of Chronic Stress
This study was funded by the Roland Ernst Foundation Project “Identification of stressors due to organizational structures in airborne and ground-based emergency service”.
Compliance with ethical standards
The study protocol was approved by the local Ethics Committee of the Medical Faculty of the Technical University of Dresden, Germany (No#EK348092011).
All participants signed the informed consent.
Conflict of interest
The authors have no conflict of interest to disclose.
- Baig A, Siddiqui I, Naqvi H, Sabir S, Jabbar J, Shahid M (2011) Correlation of serum cortisol levels and stress among medical doctors working in emergency departments. J Coll Physicians Surg Pak 16(9):576–580Google Scholar
- Cygankiewicz I, Zareba W (2013) Heart rate variability. Handb Clin Neurol 117:379–393. https://doi.org/10.1016/B978-0-444-53491-0.00031-6 CrossRefGoogle Scholar
- Dutheil F, Boudet G, Perrier C, Lac G, Ouchchane L, Chamoux A, Duclos M, Schmidt J (2012) JOBSTRESS study: comparison of heart rate variability in emergency physicians working a 24-hour shift or a 14-hour night shift—a randomized trial. Int J Cardiol 158(2):322–325. https://doi.org/10.1016/j.ijcard.2012.04.141 CrossRefGoogle Scholar
- Dutheil F, Trousselard M, Perrier C, Lac G, Chamoux A, Duclos M, Naughton G, Mnatzaganian G, Schmidt J (2013) Urinary interleukin-8 is a biomarker of stress in emergency physicians, especially with advancing age—the JOBSTRESS* randomized trial. PLoS One 8(8):6–12. https://doi.org/10.1371/journal.pone.0071658 CrossRefGoogle Scholar
- Föhr T, Tolvanen A, Myllymäki T, Järvelä-Reijonen E, Rantala S, Korpela R, Peuhkuri K, Kolehmainen M, Puttonen S, Lappalainen R, Rusko H, Kujala UM (2015) Subjective stress, objective heart rate variability-based stress, and recovery on workdays among overweight and psychologically distressed individuals: a cross-sectional study. J Occup Med Toxicol 10(1):1–9. https://doi.org/10.1186/s12995-015-0081-6 CrossRefGoogle Scholar
- Franke GH (2000) SCL-90-R. Beltz Test, GöttingenGoogle Scholar
- Inslicht SS, Otte C, McCaslin SE, Apfel BA, Henn-Haase C, Metzler T, Yehuda R, Neylan TC, Marmar CR (2011) Cortisol awakening response prospectively predicts peritraumatic and acute stress reactions in police officers. Biol Psychiatry 70(11):1055–1062. https://doi.org/10.1016/j.biopsych.2011.06.030 CrossRefGoogle Scholar
- Kuehl LK, Hinkelmann K, Muhtz C, Dettenborn L, Wingenfeld K, Spitzer C, Kirschbaum C, Wiedemann K, Otte C (2015) Hair cortisol and cortisol awakening response are associated with criteria of the metabolic syndrome in opposite directions. Psychoneuroendocrinology 51: 365–370. https://doi.org/10.1016/j.psyneuen.2014.09.012 CrossRefGoogle Scholar
- Lohmann-Haislah A (2012) Stressreport Deutschland 2012—Psychische Anforderungen, Ressourcen und Befinden. Bundesanstalt für Arbeitsschutz und Arbeitsmedizin, DortmundGoogle Scholar
- McEwen B, Lasley EL (2003) The end of stress as we know it. National Academic Press, WashingtonGoogle Scholar
- Mück-Weymann M (2011) Herzratenvariabilität (HRV) als Forschungstool für die Praxis. In: Anderssen-Reuster U (ed) Achtsamkeit in Psychotherapie und Psychosomatik, 2nd edn. Schattauer, Stuttgart, pp 303–305Google Scholar
- Nikolic-Popovic J, Goubran R (2013) Impact of motion artifacts on heart rate variability measurements and classification performance. In: 2013 IEEE international symposium on medical measurements and applications (MeMeA), pp 156–159, https://doi.org/10.1109/MeMeA.2013.6549726
- Pajonk FGB, Cransac P, Müller V, Teichmann A, Meyer W (2012) Trauma and stress-related disorders in german emergency physicians: the predictive role of personality factors. Int J Emerg Ment Health 14(4):257–268Google Scholar
- Pruessner JC, Kirschbaum C, Meinlschmid G, Hellhammer DH (2003) Two formulas for computation of the area under the curve represent measures of total hormone concentration versus time-dependent change. Psychoneuroendocrinology 28(7):916–931. https://doi.org/10.1016/S0306-4530(02)00108-7 CrossRefGoogle Scholar
- Samel A, Vejvoda M, Maass H (2004) Sleep deficit and stress hormones in helicopter pilots on 7-day duty for emergency medical services. Aviat Space Environ Med 75(11):935–940Google Scholar
- Schulz P, Schlotz W, Becker P (2004) Trierer Inventar zum chronischen Stress (TICS). Hogrefe, GöttingenGoogle Scholar
- Selye H (1983) The stress concept: past, present, and future. In: Cooper CL (ed) Stress research issues for the eighties. Wiley, New York, pp 1–20Google Scholar
- Stalder T, Kirschbaum C, Kudielka BM, Adam EK, Pruessner JC, Wüst S, Dockray S, Smyth N, Evans P, Hellhammer DH, Miller R, Wetherell MA, Lupien SJ, Clow A (2016) Assessment of the cortisol awakening response: expert consensus guidelines. Psychoneuroendocrinology 63:414–432. https://doi.org/10.1016/j.psyneuen.2015.10.010 CrossRefGoogle Scholar
- Task Force of The European Society of Cardiology and The North American Society of Pacing and Electrophysiology (1996) Heart rate variability. Standards of measurement, physiological interpretation, and clinical use. Eur Heart J 17:354–381. https://doi.org/10.1161/01.CIR.93.5.1043 CrossRefGoogle Scholar
- WHO (2001) The World Health Report 2001. Mental health: new understanding, new hope. WHO, GenevaGoogle Scholar
- Wüst S, Wolf J, Hellhammer DH, Federenko I, Schommer NC, Kirschbaum C (2000) The cortisol awakening response—normal values and confounds. Noise Health 2(7):79–88Google Scholar