Noise in Otolaryngology - Head and Neck Surgery operating rooms: a systematic review

Effect of intraoperative noise on postoperative pain in surgery patients under general anesthesia: evidence from a prospective study and mouse model

BACKGROUND

Most patients are in a noisy environment during abdominal surgery under general anesthesia. This study included patients who underwent abdominal surgery under general anesthesia and established an animal model to determine whether intraoperative noise affects postoperative pain.

MATERIALS AND METHODS

This prospective study included 200 patients who underwent abdominal surgery under general anesthesia. Intraoperative noise and electroencephalograms were continuously recorded, and the mean level and time proportion of noise intensity of greater than 70 dB were calculated. Maximum postoperative pain was assessed using a numerical rating scale at 0-12 h and 12-24 h after surgery, and postoperative analgesia consumption in patients receiving patient-controlled intravenous analgesia was recorded. Postoperative pain intensity and electroencephalogram amplitude were compared between patients with high-noise exposure (time proportion of noise intensity greater than 70 dB ≥40%) and low-noise exposure (<40%). Mechanical pain sensitivity was tested in two groups of mice with plantar incisions exposed to 40 dB or 70-100 dB.

RESULTS

The time proportion of noise intensity greater than 70 dB was identified as an independent risk factor for postoperative pain intensity ( P <0.001). P ain numerical rating scale 0-12 h (4.5±1.5 vs. 3.7±1.3, P =0.001) and 12-24 h (3.9±1.5 vs. 3.2±1.1, P =0.004) after surgery in patients with high-noise exposure was significantly higher than in patients with low-noise exposure. The electroencephalogram amplitude of patients with high-noise exposure was significantly lower than that of patients with low-noise exposure ( P <0.05). In the mouse model, mechanical hyperalgesia in the 70-100 dB group was significantly greater than that in the 40 dB group ( P <0.001).

CONCLUSION

High-level intraoperative noise exposure aggravates the degree of postoperative pain and analgesic needs of patients undergoing abdominal surgery, which may be related to the impact of noise on the neurophysiological activity of the brain and postoperative hyperalgesia.

Safety in Health Care: The Impact of Operating Room Design

The science of operating room design has grown over the past 20 years due to the realization that the physical environment influences health care provider performance and patient outcomes. Medical errors occur when the normal workflow in an operating room is disrupted as providers must overcome sub-optimal conditions. All aspects of the physical environment can impact operating room flow. Studying the layout, contents, ergonomics, and environmental parameters of the operating can lead improved work conditions resulting improved patient and provider safety. At the forefront of operating room design science is the use of simulation and the evaluation of new technologies.

Risk for Surgical Team Hearing Loss With Vitrectomy

Purpose: To assess sound-level exposure during vitrectomy using 3 of the most common commercially available machines. Methods: This noninterventional cross-sectional study examined sound emission from the Constellation, Stellaris, and EVA vitrector systems. For each machine, a noise dosimeter was used to measure the sound-level exposure of the surgeon during 3 surgical cases in which vitrectomy was performed. Sound levels associated with progressively increasing cut rates and vacuum pressures were also measured. Finally, sound measurements were taken during the use of various additional functions of each machine, including diathermy, laser, and extrusion. Sound levels were compared with occupational health guidelines in Canada and the United States. Results: The maximum sound level recorded during vitrectomy surgery was 88.2 dBA. The mean sound level during vitrectomy surgical cases ranged from 58.5 to 66.8 dBA. A strong positive linear correlation was found between the cut rate and sound level (r = 0.88-0.98) and the vacuum pressure and sound level (r = 0.83-0.97). This relationship was consistent across the 3 vitrector systems (P < .001). Conclusions: Noise exposure during vitrectomy procedures was acceptable but may be sufficient for surgical team activity interference, as described by World Health Organization recommendations. A strong correlation was found between the cut rate and noise exposure. If cut rates continue to increase, attention should be given to ensure that the resulting noise exposure does not threaten the hearing of vitreoretinal surgeons and the operating room staff.

The relationship between exposure to noise and hearing loss in orthopaedics

Aims

In the UK, the agricultural, military, and construction sectors have stringent rules about the use of hearing protection due to the risk of noise-induced hearing loss. Orthopaedic staff may also be at risk due to the use of power tools. The UK Health and Safety Executive (HSE) have clear standards as to what are deemed acceptable occupational levels of noise on A-weighted and C-weighted scales. The aims of this review were to assess the current evidence on the testing of exposure to noise in orthopaedic operating theatres to see if it exceeds these regulations.

Methods

A search of PubMed and EMBASE databases was conducted using PRISMA guidelines. The review was registered prospectively in PROSPERO. Studies which assessed the exposure to noise for orthopaedic staff in operating theatres were included. Data about the exposure to noise were extracted from these studies and compared with the A-weighted and C-weighted acceptable levels described in the HSE regulations.

Results

A total of 15 studies were deemed eligible. These included a total of 386 orthopaedic operations and the use of 64 orthopaedic instruments. A total of 294 operations (76%) and 45 instruments (70%) exceeded the regulations on an A-weighted scale, and 22% (10 of 46) of operations exceeded the maximum C-weighted peak acceptable level of noise. Noise-induced hearing loss was reported in 28 of 55 orthopaedic staff members (50.9%).

Conclusion

Safe levels of noise can be exceeded in orthopaedic operations, and when using orthopaedic instruments. Employers have clear policies about exposure to noise in the workplace but have yet to identify orthopaedic theatres as a potential at-risk area. Orthopaedic staff need education, monitoring, and protection, while employers should consider regular assessments of staff in orthopaedic theatres and offer methods to prevent noise-induced hearing loss.

Noise exposure in pediatric otolaryngology clinic: A sound survey of a single-institution tertiary care facility

BACKGROUND

The Occupational Safety and Health Administration (OSHA) considers acoustic exposure of 90 decibels (dB) an occupational risk for noise-induced hearing loss. Pediatric healthcare clinicians are exposed to considerable noise especially during invasive procedures, predisposing them to noise-induced hearing loss, increased work-related stress, and increased complications associated with intense noise exposure. While there has been extensive research in noise exposure in dentistry, to date there has been no research on noise exposure in the pediatric otolaryngology clinic setting. The objective of this study is to quantify the degree of noise exposure that pediatric otolaryngologists encounter in the clinical setting.

METHODS

A sound survey was performed of 420 pediatric otolaryngology clinic visits within a single-institution tertiary care facility from January 2022 to March 2022, with a total of 409 visits included. At each visit, noise was measured using a calibrated National Institute for Occupational Safety and Health (NIOSH) Sound Meter application, an iPad, and a microphone. The Equivalent Continuous Sound Pressure Level (LAeq), peak sound pressure level (SPL), C-weighted peak noise level (LCpeak), and the 8-hour time-weighted average (TWA) sound level were recorded.

RESULTS

The average LAeq was 61.1 dB, the median LAeq was 60.3 dB, and the average peak SPL was 80.5 dB. Only 0.5 % of visits reached an LAeq above 80 dB, however, 51 % were above 60 dB and 99 % were above 45 dB. No clinicians were exposed to noise exceeding established limits of safety. Patients younger than ten years old (p < 0.001) and those who underwent procedures such as cerumen removal (p < 0.001) elicited higher ranges of elevated noise. Multivariate analysis confirmed that increased age decreased acoustic exposure while procedures increased acoustic exposure.

CONCLUSIONS

The results of this study suggest that pediatric otolaryngology clinicians do not exceed hazardous noise limit exposure. However, they are exposed to levels above those which have been linked to stress, poor productivity, and stress-related disorders. This analysis also reports that patients who are younger and those that undergo procedures, specifically cerumen removal, tend to expose their providers to the highest levels of noise. This is the first study examining noise exposure in pediatric otolaryngology, and further research should evaluate the risks of noise exposure in this environment.

Noise in cesarean deliveries: a comprehensive analysis of noise environments in the Labor and Delivery operating room and evaluation of a visual alarm noise abatement program

BACKGROUND

Cesarean delivery is the most common major surgery worldwide. Noise in healthcare settings leads to impaired communication and concentration, and stress among healthcare providers. Limited information is available about noise at cesarean delivery.

OBJECTIVE

This study aimed to achieve a comprehensive analysis of noise that occurs during cesarean deliveries. Sound level meters are used to determine baseline noise levels and to describe the frequency of acute noise generated during a cesarean delivery that will cause a human startle response. Secondarily, we aimed to evaluate the effectiveness of a visual alarm system in mitigating excessive noise.

STUDY DESIGN

We completed a preintervention/postintervention observational study of noise levels during cesarean deliveries before and after introduction of a visual alarm system for noise mitigation between February 15, 2021 and August 26, 2021. There were 156 cases included from each study period. Sound pressure levels were analyzed by overall case median decibel levels and by time epoch for relevant phases of the operation. Rapid increases in noise events capable of causing a human startle response, "startle events," were detected by retrospective analysis, with quantification for baselines and analysis of frequency by case type. Median noise levels with interquartile ranges are presented. Data are compared between epochs and case characteristics with nonparametric 2-tailed testing.

RESULTS

The median acoustic pressure for all cesarean deliveries was 61.8 (58.8-65.9) (median [interquartile range]) dBA (A-weighted decibels). The median dBA for the full case time period was significantly higher in cases with neonatal intensive care unit team presence (62.1 [60.5-63.9]), admission to the neonatal intensive care unit (62.0 [60.4-63.9]), 5-minute Apgar score <7 (62.2 [61.1-64.3]), multiple gestations (62.6 [62.0-64.2]), and intraoperative tubal sterilization (62.8 [61.5-65.1]). The use of visual alarms was associated with a statistically significant reduction of median noise level by 0.7 dBA, from 61.8 (60.6-63.5) to 61.1 (59.8-63.7) dBA (P<.001).

CONCLUSION

The noise intensities recorded during cesarean deliveries were commonly at levels that affect communication and concentration, and above the safe levels recommended by the World Health Organization. Although noise was reduced by 0.7 dBA, the reduction was not clinically significant in reaching a discernible amount (a 3-dB change) or in reducing "startle events." Isolated use of visual alarms during cesarean deliveries is unlikely to be a satisfactory noise mitigation strategy.

Operating Room Noise and Team Communication during Facial Plastic and Reconstructive Surgery: A Multicenter Study

Operating room (OR) noise contributes to team miscommunication. In facial plastic and reconstructive surgery (FPRS), many cases are completed under sedation. This creates a unique environment wherein patients are aware of OR noise. The objectives of this study were to quantify noise and evaluate team members' perspectives on communication inside of FPRS ORs. This study was completed across three surgical institutions. Objective noise measurements were recorded with SoundMeter X. A communication questionnaire was delivered to OR team members following each case. Four hundred and twenty-three noise measurements were recorded during facelift/neck, eye/brow, rhinoplasty, and fat transfer/lip surgeries. The mean and maximum noise levels were 66.1 dB (dB) and 87.6 dB, respectively. Measurements during cases with general anesthetic (221/423, 52.2%) had higher noise measurements (70.3 dB) compared with those with sedation (202/423, 47.8%) (69.7 dB) (p = 0.04). The OR was louder with suction on (72.3 dB) versus off (69.3 dB) (p <0.00). Suction (34.5%) and music (22.4%) were the largest noise contributors according to questionnaire replies. Intraoperative noise, awake patients, and suctions/music may negatively impact FPRS OR communication. Innovation to improve FPRS intraoperative communication should be considered for effective patient care.