Alberto Lucchini1, Stefano Bambi, Silvia Gurini, Enrico Di Francesco, Luigino Pace, Roberto Rona, Roberto Fumagalli, Giuseppe Foti, Stefano Elli. 1. Alberto Lucchini, RN, General Intensive Care Unit, Emergency Department, ASST Monza, San Gerardo Hospital, Monza; and University of Milano-Bicocca, Milan, Italy. He is the coordinator of the master's degree program in intensive and critical care nursing at Milano-Bicocca University, Italy. His main publications concern the nursing workload in intensive care, nursing care of ECMO patients, invasive and non-invasive mechanical ventilation, endotracheal suctioning. Stefano Bambi, PhD, MSN, RN, Medical and Surgical Intensive Care Unit, Careggi University Hospital, Florence, Italy. He is a staff nurse and professor in charge at Florence University and Milano-Bicocca University. His main publications concern the, invasive and non-invasive mechanical ventilation, nursing in critical care settings. Silvia Gurini, RN, Emergency Department, ASST Valtellina ed Alto Lario, Italy. Enrico di Francesco, RN, Cardiosurgical Intensive Care Unit, S. Antonio Hospital, Padova, Italy. Luigino Pace, RN, General Intensive Care Unit, APSS-Santa Maria del Carmine Hospital, Rovereto, Italy. Roberto Rona, MD, General Intensive Care Unit, Emergency Department, ASST Monza, San Gerardo Hospital, Monza; and University of Milano-Bicocca, Milan, Italy. Roberto Fumagalli, MD, is a professor in the University of Milan-Bicocca located in Milan, Italy. He is also the director of the Department of Anesthesia and Intensive Care Medicine, Niguarda Ca' Granda Hospital of Milan, Italy. Giuseppe Foti, MD, General Intensive Care Unit, Emergency Department, ASST Monza, San Gerardo Hospital, Monza; and University of Milano-Bicocca, Milan. Stefano Elli, RN, General Intensive Care Unit, Emergency Department, ASST Monza, San Gerardo Hospital, Monza; and University of Milano-Bicocca, Milan.
Abstract
AIM: The aim of this study was to assess the noisiness levels produced by different gas source systems, breathing circuits setup, and gas flow rates during continuous positive airway pressure (CPAP) delivered through helmet. METHODS: This was a crossover design study. Ten healthy subjects receivedhelmet CPAP at 5 cm H2O in random order with different gas flow rates (60 and 80 L/min), 3 diverse gas source systems (A: Venturi system, B: oxygen and air flowmeters, C: electronic Venturi system), and 3 different breathing circuit configurations. During every step of this study, a heat and moisture exchanger (HME) was placed on the helmet inlet gas port to measure the effects on noise production. Noise intensity level was recorded through a sound-level meter. Participants scored their noisiness perception on a visual analog scale. RESULTS: The noise level inside the helmet ranged between 76 ± 4 and 117 ± 1 Decibel A. The gas source and the gas flow rate always affected the noise level inside and outside the helmet (P < .001). The different "breathing circuit setup" did not change the noise levels inside the helmet (P = .244), but affected the noise level outside, especially when a Venturi system was used (P < .001). An HME filter placed at the junction between the inspiratory limb of the breathing circuit and the helmet significantly decreased the noise intensity inside the helmet (mean dBA without HME, 99.56 ± 13.30 vs 92.26 ± 10.72 with HME; P < .001) and outside (mean dBA without HME, 68.16 ± 12.05 vs 64.97 ± 12.17 with HME; P < .001). The perception of noise inside the helmet was lower when an HME filter was placed on the inspiratory inlet gas port (median, 6 [interquartile range, 4-7] vs 7 [5-8]; P < .001). CONCLUSIONS: When helmet CPAP is delivered through gas flow rates up to 50 L/min, an HME placed on the helmet inlet gas port should be used to reduce noise inside the helmet and to improve patients' comfort.
RCT Entities:
AIM: The aim of this study was to assess the noisiness levels produced by different gas source systems, breathing circuits setup, and gas flow rates during continuous positive airway pressure (CPAP) delivered through helmet. METHODS: This was a crossover design study. Ten healthy subjects received helmet CPAP at 5 cm H2O in random order with different gas flow rates (60 and 80 L/min), 3 diverse gas source systems (A: Venturi system, B: oxygen and air flowmeters, C: electronic Venturi system), and 3 different breathing circuit configurations. During every step of this study, a heat and moisture exchanger (HME) was placed on the helmet inlet gas port to measure the effects on noise production. Noise intensity level was recorded through a sound-level meter. Participants scored their noisiness perception on a visual analog scale. RESULTS: The noise level inside the helmet ranged between 76 ± 4 and 117 ± 1 Decibel A. The gas source and the gas flow rate always affected the noise level inside and outside the helmet (P < .001). The different "breathing circuit setup" did not change the noise levels inside the helmet (P = .244), but affected the noise level outside, especially when a Venturi system was used (P < .001). An HME filter placed at the junction between the inspiratory limb of the breathing circuit and the helmet significantly decreased the noise intensity inside the helmet (mean dBA without HME, 99.56 ± 13.30 vs 92.26 ± 10.72 with HME; P < .001) and outside (mean dBA without HME, 68.16 ± 12.05 vs 64.97 ± 12.17 with HME; P < .001). The perception of noise inside the helmet was lower when an HME filter was placed on the inspiratory inlet gas port (median, 6 [interquartile range, 4-7] vs 7 [5-8]; P < .001). CONCLUSIONS: When helmet CPAP is delivered through gas flow rates up to 50 L/min, an HME placed on the helmet inlet gas port should be used to reduce noise inside the helmet and to improve patients' comfort.