Hospitals are meant to be places for respite and healing; however, technological advances and reliance on monitoring alarms has led to the environment becoming increasingly noisy. The coronary care unit (CCU), like the emergency department, provides care to ill patients while being vulnerable to noise pollution. The World Health Organization (WHO; Geneva, Switzerland) recommends that for optimum rest and healing, sound levels should average approximately 30 decibels (dB) with maximum readings less than 40 dB.

The purpose of this study was to measure and analyze sound levels in three different locations in the CCU, and to review alarm reports in relation to sound levels.

Over a one-month period, sound recorders (Extech SDL600; Extech Instruments; Nashua, New Hampshire USA) were placed in three separate locations in the CCU at the West Roxbury Veterans’ Administration (VA) Hospital (Roxbury, Massachusetts USA). Sound samples were recorded once per second, stored in Comma Separated Values format for Excel (Microsoft Corporation; Redmond, Washington USA), and then exported to Microsoft Excel. Averages were determined, plotted per hour, and alarm histories were reviewed to determine alarm noise effect on total noise for each location, as well as common alarm occurrences.

Patient Room 1 consistently had the lowest average recordings, though all averages were >40 dB, despite decreases between 10:00 pm and 7:00 am. During daytime hours, recordings maintained levels >50 dB. Overnight noise remained above recommended levels 55.25% of the period in Patient Room 1 and 99.61% of the same time period in Patient Room 7. The nurses’ station remained the loudest location of all three. Alarms per hour ranged from 20-26 during the day. Alarms per day averaged: Patient Room 1-57.17, Patient Room 7-122.03, and the nurses’ station - 562.26. Oxygen saturation alarms accounted for 33.59% of activity, and heart-related (including ST segment and pacemaker) accounted for 49.24% of alarms.

The CCU cares for ill patients requiring constant monitoring. Despite advances in technology, measured noise levels for the hospital studied exceeded WHO standards of 40 dB and peaks of 45 dB, even during night hours when patients require rest. Further work is required to reduce noise levels and examine effects on patient satisfaction, clinical outcomes, and length of stay.

RyanKM , GagnonM , HannaT , MelloB , FofanaM , CiottoneG , MolloyM . Noise Pollution: Do We Need a Solution? An Analysis of Noise in a Cardiac Care Unit. Prehosp Disaster Med. 2016;31(4):432–435.