Variabilidade da frequência cardíaca e a percepção do estresse mental entre médicos residentes e estudantes de medicina em um plantão de emergência

Abstract

When Medical Residents (MR) and Medical Students (MS) are assigned to the demanding environment of an Emergency they inevitably encounter stress: the management of multiple demands and the life-and-death situations. All those factors are stressors in these providers in training. This can impact not only their performance and learning, but also the development of cardiovascular diseases and burnout. Heart rate variability is being considered a promising parameter for the measurement of objective physiological stress by assessing the fluctuations in heart beats from the interaction between the sympathetic (SNS) and the parasympathetic nervous system (PNS). The aims of this study are to measure short-term heart rate variability (HRV) before and after shifts, estimate perceived stress levels, and assess the recovery patterns of both medical students (MS) and residents (MR) after their shifts. We assessed HRV parameters in MS and MR using the wristband physiological monitor Polar® Verify Sense before and after day (DS) and night shifts (NS). Perceived stress levels were evaluated using the simplified State Trait Anxiety Inventory (STAI-S6) and the Subjective Units of Distress Scale. This study included 60 participants of which 55% were female with a mean age of 26 years. MS presented significant reduction in sympathetic nervous system index after DS (1.42±2.07 vs 0.32±1.54, p=0.001) and NS (0.97±1.64 vs 0.29±1.24, p=0.004), while MR maintained the same levels of sympathetic activity (DS: 1.41±1.66 vs 0.88±1.04, p=0.138; NS: 1.41±1.13 vs 1.24±1.20, p=0.399). Psychological data from STAI-S6 showed statistically significant differences when comparing before and after DS in both groups, with more perceived stress after than before DS (MS: 12±4 vs 14±4, p=0.042; MR: 14±4 vs 16±4, p=0.040), which was not observed at NS (MS: 12±3 vs 12±3, p=0.843; MR: 15±3 vs 15±4, p=0.400). Short-term HRV recordings before and after day or night shifts among medical students and residents revealed heightened sympathetic activity preceding each shift, with a more pronounced and sustained increase observed in the medical resident population.