Stress-Management durch den Einsatz eines lärmmindernden Informations-Management-Systems bei herzchirurgischen Eingriffen
by Kamar Sultan
Date of Examination:2024-07-30
Date of issue:2024-07-19
Advisor:PD Dr. Martin Friedrich
Referee:PD Dr. Martin Friedrich
Referee:PD Dr. Reiner Wäschle
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Abstract
English
Noise levels in a cardiac operating theatre are extremely high due to the equipment used. Peak levels of up to 120 decibels can be reached at short notice. In addition to the noise generated by the equipment, communication within the surgical team must be twice as loud as the ambient noise to ensure the necessary safe exchange of information. Communication is complex and takes place at several levels. The high noise level with high information density leads to significant stress for all members of the surgical team. It can be assumed that these are not ideal working conditions for achieving the best possible results. One of the consequences is the release of stress hormones. The Silent Operating Theatre Optimisation System - SOTOS© was developed by Friedrich et al. (2017) to improve this particular problem constellation. At its core, SOTOS© consists of a digital audio workstation that processes complex audio structures and distributes them to receivers and transmitters close to the body using headphones and special headphones and special microphones. Each participant has their own audio bus in SOTOS© where they receive only the information that is relevant to them and, if necessary, music that they find pleasant. The study to measure the effectiveness of SOTOS© was designed as a randomised, single-blind, interdisciplinary trial. The design was reviewed and approved by the Ethics Committee of the University Medical Center Göttingen. 22 operations were randomised into two groups. Comparable heart operations were performed in the same working environment, once without SOTOS© (control group) and once with SOTOS©. 45 volunteer study participants were examined in their 6 different roles (surgeon, assistant, instrumentation, jumper, perfusionist, anaesthesiologist). In this study, SOTOS© was tested for its effectiveness in reducing stress reactions to the individual roles in the surgical team during cardiac surgery. Stress is perceived and dealt with very individually (Lazarus 2006). Stress is not always negative. However, stress becomes relevant in the context of this study, the performance or success of the surgical team. This has a significant impact on the outcome of patients undergoing surgery and is also relevant to patient safety. In parallel with the development of various stress models, it has been shown that stress can also be measured using physiological parameters. Physiological parameters include steroid hormones, in particular cortisol, alpha-amylase, heart rate and heart rate variability. heart rate and heart rate variability. All of these parameters can be measured non-invasively. Cortisol and alpha-amylase can also be measured in oral saliva. The increase in cortisol is analogous to that of serum cortisol, but with a delay to the stressor. Despite a circadian cortisol pattern, a physiological response to a stressful situation is present and measurable. Salivary amylase also follows a stressor, but with a shorter delay. In contrast to the strong circadian rhythm of cortisol, which also varies from individual to individual, salivary alpha-amylase does not show such a diurnal rhythm. This study revealed interesting enzyme processes that provide important information about the individual stress experience, but also about the stress in the different roles in the surgical team. Overall, the surgeon consistently experienced the highest levels of stress and benefited the most from the use of SOTOS©. The instrumentation staff tended not to benefit from SOTOS. Possible reasons for this were identified. Further studies should show whether this important role in the team can be enabled to reduce stress through an optimised SOTOS©. Because of the possibility of non-invasive measurement, a continuous electrocardiogram was recorded from all team members throughout the operation. The plan was to calculate heart rate variability as a measure of stress experienced. A decreasing variability of RR intervals correlates well with increasing experience of stress. However, as important prerequisites for a valid evaluation of the calculated statistical parameters could not be met, an extensive heart rate analysis was carried out together with the statisticians. This also yielded interesting results, indicating different levels of stress in the surgical team. Again, it was the surgeon who benefited from SOTOS© almost across the board. Overall, the statistical analyses of the data collected show a clear result in favour of the SOTOS in terms of stress reduction during cardiac surgery interventions. Larger future studies with SOTOS should further substantiate the effects and investigate other important aspects, such as the influence on patient outcomes (e.g. complication rates) and hygienic benefits (SOTOS© is significantly quieter and less noisy on the operating table).
Keywords: Noise; SOTOS©; stress; cardiac surgery; Communication; heart rate; heart rate variability