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Prospective Trial on Noise Reduction in Surgical Operating Theaters

This study has been completed.
University of Zurich
Technische Universität Dresden
Information provided by (Responsible Party):
Carsten Engelmann, Hannover Medical School Identifier:
First received: June 4, 2012
Last updated: June 5, 2012
Last verified: June 2012

Aim of Study: Adverse effects from noise pollution in operation theatres have been throughly demonstrated. We assessed the impact of a noise reduction program in paediatric surgery.

Methods: A prospective controlled study on 156 operations performed by 16 surgeons was conducted. The sound levels before and after a noise reduction program based on education, rules and technical devices (Sound Ear tm) were assessed. Endpoints were spatially resolved sound levels matched by the surgeon's biometric (saliva cortisol, electrodermal activity) and behavioural stress responses (questionnaires). These were correlated with mission protocols and NoiSeQ for individual noise sensitivity.

Condition Intervention
Efficacy of a Noise Reduction Program
Surgical Complications
Sound Pressures in the Operating Theatre
Behavioral: Noise reduction work place rules
Behavioral: Presence of an examiner in the concerned theatre

Study Type: Interventional
Study Design: Allocation: Non-Randomized
Intervention Model: Crossover Assignment
Masking: Single Blind (Participant)
Primary Purpose: Health Services Research
Official Title: Noise Reduction Programme by Work Rules and Technical Devices (i.e.SoundEar-TM)for Surgical Theathres

Resource links provided by NLM:

Further study details as provided by Hannover Medical School:

Primary Outcome Measures:
  • Noise level (dB(A)) in the operation room at the surgeon's place [ Time Frame: continous during operation ]
    noise levels are sampled simultaneously at 4 point (surgeon, nurses 1+2 and anestesiology workplace

Secondary Outcome Measures:
  • Surgeons intraoperative biometric and psychometric stress response [ Time Frame: before, during and after operations ]
    Surgeons Cortisol Levels and Electrodermal activity are measured as he/she is submitted to questionnaires.

Enrollment: 16
Study Start Date: September 2010
Study Completion Date: April 2012
Primary Completion Date: November 2011 (Final data collection date for primary outcome measure)
Arms Assigned Interventions
No Intervention: Reference group - cloaked noise meters

Reference group or phase 1

Theatre equipped with multiple sound meters disguised as CO2 meter for sound probing in the absence of a research clerk with personnel completely unaware of sound measurements.

Sham Comparator: Control Noise AND Stress measurements

Control Group - Phase 2

No intervention but research clerk is present in theatre to protocoll the operation and test for stress by collecting saliva cortisol and probing electrodermal activity

Behavioral: Presence of an examiner in the concerned theatre
Research Clerk present in theatre, writes on note pad.
Experimental: Noise Reduction Intervention Group

Intervention Group - Phase 3

A panel of noise reduction measures (staff workplace rules, technical devices as optical noise warners, optical telephones) is put into effect. Surgeons are monitored by biometry, psychometry and the outcome.

Behavioral: Noise reduction work place rules

Information conferences for all theatre staff (100%)on the detrimal effects of high noise levels in the operating theatre. Issue of "workplace rules" on handouts and poster on theatre doors: Ban of all mobile phones from theatre. Only conversations about the ongoing case are allowed. No restocking etc. during an operation and no work in this operating room concerning other patients (e.g. later on the list). Turnig of of unnecessary suckers, warming devices etc. . No in and out during the procedure.

Technical: Sound Ears (TM, Sound Ear A.S. Copenhagen, Denmark) taped to all 4 Walls. Optical Telephones.

Other Name: Sound Ears (TM, Sound Ear A.S. Copenhagen, Denmark)

Detailed Description:

We recorded median noise levels in the control vs. interventional group including the count of peak events with different tresholds.

Three phases were conducted: 1. Reference group/phase I 2. Control group/phase II The full data set was recorded by a research clerk present in theatre however all staff were left unaware of the study purpose 3. Intervention group/phase III. The intervention consisted of a panel of work rules including mainly communication regulations (only conversations concerning the current case were allowed, no in and out during surgery, mobile phone ban etc.. Measures were backed by intervention conferences, posters and pictograms. .

A wear off-effect was sought after . Biometrically, we analyzed the surgeon's pre- to postoperative rise in cortisol and the proportion of the surgeon's electrodermal potentials of >15µS indicating severe stress. Intra-team communication, a decrease in disturbing conversations and sudden noise peaks were investigated and correlated with the individual noise sensitivity determined by the noise Q questionnaire.


Ages Eligible for Study:   up to 16 Years   (Child)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   Yes

Inclusion Criteria:

  • all operations of our tertiary referral center practice of the regular day programme involving children from preterm babies up to children of 16 years of age including emergencies at regular hours with a duration of > 20 mins and < 5 hours

Exclusion Criteria:

  • After hour emergency surgery
  • Pediatric surgery cardiac cases
  • surgeries <20 mins/>5hrs
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Please refer to this study by its identifier: NCT01612754

Pediatric Surgery Department
Hannover, Lower Saxony, Germany, 30625
Sponsors and Collaborators
Hannover Medical School
University of Zurich
Technische Universität Dresden
Principal Investigator: Carsten R Engelmann, MD, PhD Hannover Medical School, Germany
  More Information

Responsible Party: Carsten Engelmann, Oberarzt Kinderchirurgie, Hannover Medical School Identifier: NCT01612754     History of Changes
Other Study ID Numbers: SA 02
Study First Received: June 4, 2012
Last Updated: June 5, 2012

Keywords provided by Hannover Medical School:
Reduction of noise pollution
Specifically enforced workplace rules
Sound Ears (TM)
Error processed this record on April 27, 2017