Impact of sound levels on physiological and consciousness state of cardiovascular patients

Abstract

Background: Patients treated in intensive care units (ICUs) experience life-threatening medical conditions but some external factors in ICUs do not help or even adversely affect and complicate their evolution. Among others, such factors include noise pollution due to alarms and medical clinical equipment, as well as the activities of the health care personnel themselves.

Aim: This study aimed to evaluate the influence of elevated sound levels on physiological variables and the consciousness state of patients treated in a cardiovascular area in an ICU.

Design: A longitudinal study with several observations was carried out during 1 month in the cardiovascular area of an ICU of a third-level hospital in southern Spain.

Methods: Sound levels were monitored in different work shifts and patients' physiological data and consciousness status were recorded. Generalized additive mixed models (GAMMs) were developed to detect the variability of the sound levels together with the vital parameters of the patients in the ICU.

Results: Thirty-eight patients were included. The mean sound level was 54.09 dBA. The GAMM sound levels analysis showed a significant increase in sound levels from 4:30 p.m. to 8:00 p.m. (1.83 dBA; P < .001) and 8:00 p.m. to 11:30 p.m. (3.06 dBA; P < .001). An increase in heart rate (3.66 bpm; P < .001), respiratory rate (2.62 rpm; P < .001) and the Glasgow Coma Scale (0.50 units; P = .002) was detected during the 4:30 p.m.-8:30 p.m.

Conclusions: Elevated sound levels in cardiovascular ICUs seem to influence positively the physiological and consciousness status of patients. Given the importance of the findings for patient safety, future intervention studies are recommended.

Relevance to clinical practice: The finding of this study could translate into structural changes in ICU facilities, as well as the development of clinical practice guidelines that influence the behaviour of health care professionals.

Keywords: critically ill patients; environment; intensive care unit; noise; safety culture.