Do Filters Affect Humidity Levels Within Helmet-CPAP Powered by the Venturi System? Insights from a Bench-top Study.
Objective: Helmet continuous positive airway pressure (H-CPAP) systems powered by Venturi devices are widely used for noninvasive respiratory support in acute hypoxaemic respiratory failure. Although mechanical filters are often added to reduce noise and improve environmental safety, their impact on...
| Publicado en: | Dimensions of Critical Care Nursing Vol. 45; no. 3; pp. 149 - 155 |
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| Autores principales: | , , , , , , , , |
| Formato: | pictorial research tables/charts Journal Article |
| Publicado: |
Lippincott Williams & Wilkins
May/Jun2026
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| Acceso en línea: | Ver este registro en EBSCOhost |
| fields | @attributes: recordID: 1 pdfLink: plink: https://search.ebscohost.com/login.aspx?direct=true&db=ccm&AN=192699568&site=ehost-live header: @attributes: shortDbName: ccm uiTerm: 192699568 longDbName: CINAHL Complete uiTag: AN controlInfo: bkinfo: dissinfo: jinfo: jid: 07304625 48N jtl: Dimensions of Critical Care Nursing issn: 07304625 maglogo: N pubinfo: dt: May/Jun2026 vid: 45 iid: 3 pid: 5086 pub: Lippincott Williams & Wilkins place: Baltimore, Maryland artinfo: ui: 192699568 192699568 192699568 10.1097/DCC.0000000000000754 192699568 ppf: 149 ppct: 6 formats: tig: atl: Do Filters Affect Humidity Levels Within Helmet-CPAP Powered by the Venturi System? Insights from a Bench-top Study. aug: au: delle Vergini, Michele Lucchini, Alberto Antonacci, Chiara Turra, Giulia Foti, Giuseppe Bambi, Stefano Coppadoro, Andrea Giani, Marco Rezoagli, Emanuele affil: School of Medicine and Surgery, University of Milano-Bicocca, Milano, Italy sug: subj: Continuous Positive Airway Pressure Methods Continuous Positive Airway Pressure Equipment and Supplies Air Filters Humidity Evaluation Oxygen Therapy Italy Clinical Laboratories Hospitals, Public Experimental Studies One-Way Analysis of Variance Descriptive Statistics Data Analysis Software Equipment Design Models, Anatomic ab: Objective: Helmet continuous positive airway pressure (H-CPAP) systems powered by Venturi devices are widely used for noninvasive respiratory support in acute hypoxaemic respiratory failure. Although mechanical filters are often added to reduce noise and improve environmental safety, their impact on gas humidification, flow, and FiO₂ delivery remains unclear. This bench-top study aimed to evaluate how the use of different filter types and configurations affects the humidity within the helmet. The secondary objective was to assess the changes in FiO₂ and flow associated with filter placement. Methods: A bench-top study was conducted at the Respiratory Physiology Laboratory of the Italian University Hospital using a medium-sized CPAP helmet connected to a Venturi flow generator. Seven mechanical filters (5 HEPA and 2 HME) were tested in 3 configurations: no filter, 1 filter between the Venturi flowmeter and helmet gas-in, and 2 filters (post-flowmeter and Venturi air inlet). Temperature, relative humidity, flow, and FiO₂ were measured under 3 FiO₂ settings (0.35, 0.55, 0.75). Results: The addition of filters led to a statistically significant reduction in the absolute humidity inside the helmet (P <0.05). At FiO₂ 0.75, the absolute humidity decreased from 7.31 mgH₂O/L without filters to 6.64 mgH₂O/L with 2 filters. The use of filters led to a small yet notable rise in FiO₂ (from 0.46±0.11 with no filter to 0.48±0.12 with 2 filters; P =0.001) and a corresponding decrease in flow (from 1.37±0.34 L/s to 1.17±0.30 L/s; P =0.003). By setting the FiO2 to <0.55 and incorporating a single filter into the Venturi air port, external water vapour was allowed to enter the helmet, approaching the recommended level of 10 mgH2O/L. Conclusions: Mechanical filters in H-CPAP systems reduce humidification and flow while increasing FiO₂. These effects should be carefully considered in clinical practice to maintain patient comfort and therapeutic effectiveness, particularly in settings without active humidification. pubtype: Academic Journal doctype: pictorial research tables/charts Journal Article ougenre: Article language: English refInfo: holdings: @attributes: islocal: N |
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