Contribution of alarm noise to average sound pressure levels in the ICU: An observational cross-sectional study. (December 2020)

• Record Type: Journal Article
• Authors: Vreman, Jeanette; van Loon, Lex M.; van den Biggelaar, Wilma; van der Hoeven, Johannes G.; Lemson, Joris; van den Boogaard, Mark
• Is Part Of: Intensive and critical care nursing. Volume 61(2020)
• Publication Date: 2020-12
• Subjects: Acoustics -- Alarms -- Critical care -- Noise -- Patient safety -- Sound; Intensive care nursing -- Periodicals; Critical Illness -- nursing -- Periodicals; Intensive Care -- Periodicals; Nursing Care -- Periodicals; Intensive care nursing; Periodicals; Electronic journals; 616.028
• DOI: 10.1016/j.iccn.2020.102901
• Languages: English
• ISSNs: 0964-3397

Abstract

Highlights: Mean sound levels of over 53-55dBA in the ICU are exceeding WHO recommendations. Over 175, 000 alarms were recorded of which 85% were exceeding limits alarms. The contribution of alarms to mean noise levels in the ICU is limited. Alarm lead to a slight decrease the noise level (1 dBA). Noise reducing interventions should focus on other causes than alarm frequency. Abstract: Objectives: To explore sound levels, alarm frequencies and the association between alarms and sound levels. Design: A single center observational cross-sectional study. Setting: Four intensive care units. Main outcome measures: Contribution of alarms: red (life threatening), yellow (indicate excess of limits) and blue (technical) to sound pressure levels dB(A) at nursing stations. Results: Mean sound pressure levels differed significantly between day (56.1 ± 5.5), evening (55.1 ± 5.7) and night periods 53.6 ± 5.6; p < 0.01. 175, 996 alarms were recorded of which 149, 764 (85%) were yellow, 18, 080 (10%) were red and 8, 152 (5%) were blue. The mean sound levels without alarms (background) is 56.8 dB(A), with only red: 56.0 dB(A), only yellow: 55.6 dB(A), only blue: 56.0 dB(A) and mixed alarms: 56.3 dB(A). Yellow alarms (b = −0.93; 95% CI: −1.26 to −0.6; p < 0.001) were weakly but significantly associated with mean sound levels and lead to a slight decrease in noise level (1 dB), Red alarms (b = −0.3; 95% CI: −1.237 to 0.63; p = 0.52). The R Square of the model with all alarms was 0.01 (standard error of estimate, 6.9; p < 0.001). Conclusions: Sound levels were high during all day-periods. Alarms exceeding limits occurred most frequently. However, the contribution of alarms to sound levels measured at the nursing station is clinically limited.