The Effect of Filters on CPAP Delivery by Helmet

CPAP; emergency department; noise; noninvasive ventilation; respiratory insufficiency; Continuous Positive Airway Pressure; Hot Temperature; Humans; Noise; Article; breathing pattern; disease severity; flow rate; fraction of inspired oxygen; gas flow; helmet continuous positive airway pressure; human; hypoxemia; oxygenation; rebreathing; static electricity; heat; positive end expiratory pressure ventilation; procedures

Abstract :

[en] BACKGROUND: When helmet CPAP is performed using a Venturi system, filters are frequently interposed in the respiratory circuit to reduce noise within the helmet. The effect of the interposition of these filters on delivered fresh gas flow and the resulting FIO2 is currently unknown. METHODS: In a bench study, 2 different Venturi systems (WhisperFlow and Harol) were used to generate 3 different gas flow/FIO2 combinations (80 L/min-FIO2 0.6, 100 L/min-FIO2 0.5, 120 L/min-FIO2 0.4). Different combinations of filters were applied at the flow generator input line and/or at the helmet inlet port. Two types of filters were used for this purpose: a heat and moisture exchanger filter and an electrostatic filter. The setup without filters was used as baseline. Gas flow and FIO2 were measured for each setup. RESULTS: Compared to baseline, the interposition of filters reduced the gas flow between 1–13% (P < .001). The application of a filter at the Venturi system or at the helmet generated a comparable flow reduction (-3 ± 2% vs-4 ± 2%, P = .12), whereas a greater flow reduction (-7 ± 4%) was observed when filters were applied at both sites (P < .001). An increase in FIO2 up to 5% was observed with filters applied. A strong inverse linear relationship (P < .001) was observed between the resulting gas flow and FIO2. CONCLUSIONS: The use of filters during helmet CPAP reduced the flow delivered to the helmet and, consequently, modified FIO2. If filters are applied, an adequate gas flow should be administered to guarantee a constant CPAP during the entire respiratory cycle and avoid rebreathing. Moreover, it might be important to measure the effective FIO2 delivered to the patient to guarantee a precise assessment of oxygenation. © 2022 Daedalus Enterprises.

Disciplines :

Nursing Science

Author, co-author :

PRIVITERA, Daniele ; University of Luxembourg > Faculty of Science, Technology and Medicine (FSTM) > Department of Life Sciences and Medicine (DLSM) > Medical Education ; Department of Emergency Medicine, ASST Grande Ospedale Metropolitano Niguarda, Milan, Italy

Capsoni, Nicolò; Department of Emergency Medicine, ASST Grande Ospedale Metropolitano Niguarda, Milan, Italy

Zadek, Francesco; Department of Medicine and Surgery, University of Milan-Bicocca, Monza, Italy ; Department of Anesthesia and Intensive Care Medicine, Niguarda Ca’ Granda, Milan, Italy

Vailati, Paolo; Department of Emergency Medicine, ASST Grande Ospedale Metropolitano Niguarda, Milan, Italy

Airoldi, Chiara; Department of Translation Medicine, University of Piemonte Orientale, Novara, Italy

Cozzi, Mattia; Department of Emergency Medicine, ASST Grande Ospedale Metropolitano Niguarda, Milan, Italy

Pierotti, Federico; Department of Emergency Medicine, ASST Grande Ospedale Metropolitano Niguarda, Milan, Italy

Fumagalli, Roberto; Department of Medicine and Surgery, University of Milan-Bicocca, Monza, Italy ; Department of Anesthesia and Intensive Care Medicine, Niguarda Ca’ Granda, Milan, Italy

Bellone, Andrea; Department of Emergency Medicine, ASST Grande Ospedale Metropolitano Niguarda, Milan, Italy

Langer, Thomas; Department of Medicine and Surgery, University of Milan-Bicocca, Monza, Italy ; Department of Anesthesia and Intensive Care Medicine, Niguarda Ca’ Granda, Milan, Italy

External co-authors :

Language :

English

Title :

The Effect of Filters on CPAP Delivery by Helmet

Publication date :

2022

Journal title :

Respiratory Care

ISSN :

0020-1324

Publisher :

American Association for Respiratory Care

Volume :

Issue :

Pages :

995 - 1001

Peer reviewed :

Peer Reviewed verified by ORBi

Available on ORBilu :

since 26 November 2025

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Bibliography

Weng CL, Zhao YT, Liu QH, Fu CJ, Sun F, Ma YL, et al. Meta-analysis: noninvasive ventilation in acute cardiogenic pulmonary edema [published correction appears in Ann Intern Med. 2010 Aug 17;153 (4):280] [published correction appears in Ann Intern Med. 2010 Jul 6;153(1):67]. Ann Intern Med. 2010;152(9):590-600.
Collins SP, Mielniczuk LM, Whittingham HA, Boseley ME, Schramm DR, Storrow AB. The use of noninvasive ventilation in emergency department patients with acute cardiogenic pulmonary edema: a systematic review. Ann Emerg Med 2006;48(3):260-269.e2694.
Vital FM, Ladeira MT, Atallah AN. Noninvasive positive pressure ventilation (CPAP or bi-level NPPV) for cardiogenic pulmonary edema. Cochrane Database Syst Rev 2013(5)CD005351.
Cosentini R, Brambilla AM, Aliberti S, Bignamini A, Nava S, Maffei A, et al. Helmet continuous positive airway pressure vs oxygen therapy to improve oxygenation in community-acquired pneumonia: a randomized controlled trial. Chest 2010;138(1):114-120.
Ferrer M, Esquinas A, Leon M, Gonzalez G, Alarcon A, Torres A. Noninvasive ventilation in severe hypoxemic respiratory failure: a randomized clinical trial. Am J Respir Crit Care Med 2003;168(12):1438-1444.
Patel BK, Wolfe KS, Pohlman AS, Hall JB, Kress JP. Effect of noninvasive ventilation delivered by helmet vs face mask on the rate of endotracheal intubation in patients with acute respiratory distress syndrome: a randomized clinical trial. JAMA 2016;315(22):2435-2441.
Crimi C, Noto A, Princi P, Esquinas A, Nava S. A European survey of noninvasive ventilation practices. Eur Respir J 2010;36(2):362-369.
Coppadoro A, Zago E, Pavan F, Foti G, Bellani G. The use of head helmets to deliver noninvasive ventilatory support: a comprehensive review of technical aspects and clinical findings. Crit Care 2021 Sep 8;25(1):327.
Isgrò S, Zanella A, Giani M, Abd El Aziz El Sayed Deab S, Pesenti A, Patroniti N. Performance of different PEEP valves and helmet outlets at increasing gas flow rates: a bench top study. Minerva Anestesiol 2012;78(10):1095-1100.
Brusasco C, Corradi F, De Ferrari A, Ball L, Kacmarek RM, Pelosi P. CPAP devices for emergency prehospital use: a bench study. Respir Care 2015;60(12):1777-1785.
British Thoracic Society Standards of Care Committee. Noninvasive ventilation in acute respiratory failure. Thorax 2002;57(3):192-211.
Glover GW, Fletcher SJ. Assessing the performance of the WhisperFlow continuous positive airway pressure generator: a bench study. Br J Anaesth 2009;102(6):875-881.
Pisani L, Carlucci A, Nava S. Interfaces for noninvasive mechanical ventilation: technical aspects and efficiency. Minerva Anestesiol 2012;78 (10):1154-1161.
Cavaliere F, Conti G, Costa R, Proietti R, Sciuto A, Masieri S. Noise exposure during noninvasive ventilation with a helmet, a nasal mask, and a facial mask. Intensive Care Med 2004;30(9):1755-1760.
Cavaliere F, Conti G, Costa R, Spinazzola G, Proietti R, Sciuto A, Masieri S. Exposure to noise during continuous positive airway pressure: influence of interfaces and delivery systems. Acta Anaesthesiol Scand 2008 Jan;52(1):52-56.
Lucchini A, Bambi S, Gurini S, Di Francesco E, Pace L, Rona R, et al. Noise level and comfort in healthy subjects undergoing high-flow helmet continuous positive airway pressure. Dimens Crit Care Nurs 2020;39(4):194-202.
Wilkes AR. Heat and moisture exchangers and breathing system filters: their use in anesthesia and intensive care. Part 2-practical use, including problems, and their use with pediatric patients. Anaesthesia 2011;66(1):40-51.
Hernández-Molina R, Fernández-Zacarías F, Benavente-Fernández I, Jiménez-Gómez G, Lubián-López S. Effect of filters on the noise generated by continuous positive airway pressure delivered via a helmet. Noise Health 2017;19(86):20-23.
Vaz S, Falkmer T, Passmore AE, Parsons R, Andreou P. The case for using the repeatability coefficient when calculating test-retest reliability. PLoS One 2013 Sep 9;8(9):e73990.
Bland JM, Altman DG. Measurement error. BMJ 1996;313(7059):744.
Wilkes AR. Heat and moisture exchangers and breathing system filters: their use in anesthesia and intensive care. Part 1-history, principles, and efficiency. Anaesthesia 2011;66(1):31-39.
Lucato JJ, Tucci MR, Schettino GP, Adams AB, Fu C, Forti G Jr, et al. Evaluation of resistance in 8 different heat and moisture exchangers: effects of saturation and flow rate/profile. Respir Care 2005 May;50(5):636-643.
Ploysongsang Y, Branson R, Rashkin MC, Hurst JM. Pressure flow characteristics of commonly used heat-moisture exchangers. Am Rev Respir Dis 1988;138(3):675-678.
Berglund B, Lindvall T, Schwela DH. New WHO guidelines for community noise. Noise Vib Worldw 2000;31(4):24-29.
Orellana D, Busch-Vishniac IJ, West JE. Noise in the adult emergency department of Johns Hopkins Hospital. J Acoust Soc Am 2007;121 (4):1996-1999.
Tijunelis MA, Fitzsullivan E, Henderson SO. Noise in the ED. Am J Emerg Med 2005;23(3):332-335.
Donchin Y, Seagull FJ. The hostile environment of the intensive care unit. Curr Opin Crit Care 2002;8(4):316-320.
Patroniti N, Foti G, Manfio A, Coppo A, Bellani G, Pesenti A. Head helmet versus face mask for noninvasive continuous positive airway pressure: a physiological study. Intensive Care Med 2003;29(10):1680-1687.
Taccone P, Hess D, Caironi P, Bigatello LM. Continuous positive airway pressure delivered with a “helmet”: effects on carbon dioxide rebreathing. Crit Care Med 2004;32(10):2090-2096.