May 24, 2021

Breathing filters - Pleated hydrophobic vs electrostatic

By Catherine Kane, Cytiva

Our pleated hydrophobic breathing filters vs electrostatic breathing filters

The world continues to face an unprecedented healthcare crisis caused by a pandemic novel beta coronavirus, the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Protecting patients, staff, and equipment from viral contamination has been of utmost importance during the pandemic. However, there are no clear guidelines regarding exactly which type of breathing filter is best suited for each application. Which brings us to the question: what factors do you need to consider when choosing a breathing filter? Certainly, using high-efficiency breathing filters is one way of preventing viral contamination when working with patients receiving mechanical ventilation. Since the beginning of the pandemic, several societies around the world have recognized the importance of high-quality breathing filters.

Table 1. Relevant recommendations on the use of high-efficiency breathing system filters during the SARS-CoV-2 pandemic

Society Date
Canadian Anesthesiologists Society, Canada March 16, 2020 (1)
American Society of Anesthesiologists, USA April 1, 2020 (2)
Association of Anesthetists, UK April 2, 2020 3 April 2, 2020 (3)
Anesthesia Patient Safety Foundation, USA May 18, 2020 (4)
Safe Airway Society, AUS/NZ April 1, 2020 (5)
The Australian and New Zealand Intensive Care Society April 15, 2020 (6)
European Resuscitation Council, EU April 24, 2020 (7)

The COVID-19 pandemic has raised the importance of viral infection prevention

There is no doubt that patient safety and outcomes are the driving factors when deciding on products for our patients. Furthermore, healthcare providers require compelling evidence and data behind these choices. There are many different types of breathing circuit filters used on ventilators and anesthesia machines, and it is important to know if your healthcare facility is using a suitable filter to protect your patients and staff from viral infection. Let’s compare pleated hydrophobic breathing filters from Cytiva to commonly used electrostatic breathing filters. All company information is from internal and third-party validated testing; data for electrostatic filters are from published, publicly available sources.

Table 2. Comparison of Cytiva pleated hydrophobic breathing filters vs electrostatic breathing filters. Our breathing filters include the following US part codes: BB100A, BB100AF, BB50T, BB25A, BB25AB, BB25ABN. Specific part codes may vary by geography

Characteristic Pleated hydrophobic filters (Cytiva) Electrostatic filters
Tolerance to humidity and droplets, liquid challenge Hydrophobic fibers: 100% retention of liquid-borne contamination at > 50 cm water column (8) Wilkes: 27% (39/144) of electrostatic filters allowed water to pass through in laboratory testing (9); “[Patient] secretions may adhere to the filter material and prevent adequate ventilation” (10)
Filtration efficiency NaCl penetration of 0.019% to 0.056% for three filters tested by Wilkes (9) NaCl penetration of 0.252% to 35.3% for the 24 electrostatic filters tested by Wilkes (9)
Viral and bacterial retention > 99.999% retention of monodispersed bacterial and viral contaminants (15) Wilkes: “Pleated hydrophobic filters reduce gas-borne transmission of bacteria, viruses and NaCl particles more effectively than electrostatic filters” (10)
Validation for the retention of airborne contamination Tested and validated against Myobacterium tuberculosis (11), Myobacterium bovis (12), Pseudomonas species (13), Serratia marcescens (14), MS2 virus (15), Human Influenza A (H1N1) virus (16) Allowed a higher percentage of Bacillus subtilis var. niger, Viral MS-2 and sodium chloride particles (the most penetrating particle size) to pass through the filter when compared to pleated hydrophobic filters (10)
Validation for the retention of liquid-borne contamination and bloodborne viruses Tested and validated against HIV (17), Hepatitis C (18), Staphylococcus aureus (19), Pseudomonas aeruginosa (19), liquid borne latex allergens (21) and infective prion proteins (PrPSC)(22) 7/7 tests allowed for transfer of Hepatitis C (17) and 5/6 tests allowed for transfer of HIV (18) through an electrostatic filter. 3/3 filters tested against Pseudomonas aeruginosa and Staphylococcus aureus allowed for the passage of organisms through the filter (19)

Selecting the right breathing filter for your patients

If the retention of bacterial and viral particles is a deciding factor to which filter to choose for your patients, then our pleated hydrophobic filters have been shown to out-perform electrostatic filtration. Unsure of which filter membrane your medical center is using? Send us your filters: We can research the type of filter membrane and make recommendations for your medical center.

Learn more about our breathing filters.

References

  1. Canadian Anesthesiologists’ Society. COVID-19 Recommendations during Airway Manipulation. https://www.cas.ca/CASAssets/Documents/News/Updated-March-25-COVID-19_CAS_ Airway_Vsn_4.pdf. [Accessed: 2021 Mar 16].
  2. 2. American Society of Anesthesiologists. COVID-19 Information for Health Care Professionals. https://www.asahq.org/about-asa/governance-and-committees/asa-committees/committee-on-occupational-health/coronavirus. Accessed 2021 Mar 16].
  3. Association of Anesthetists. Anaesthetic Management of Patients During a COVID-19 Outbreak. https://anaesthetists.org/Home/Resources-publications/Anaesthetic-Management-of-Patients-During-a-COVID-19-Outbreak. Accessed 2021 Mar 16].
  4. Anesthesia Patient Safety Foundation. FAQ On Anesthesia Machine Use, Protection, And Decontamination During The Covid-19 Pandemic. https://www.apsf.org/faq-on-anesthesia-machine-use-protection-and-decontamination-during-the-covid-19-pandemic/#machine. Accessed [2021 Mar 17].
  5. Brewster DJ, Chrimes N, Bo TB, Fraser K, Groombridge CJ, Higgs A, et al. Consensus statement: Safe Airway Society principles of airway management and tracheal intubation specific to the COVID- 19 adult patient group [published correction appears in Med J Aust. 2020 Oct;213(7):312]. Med J Aust. 2020;212(10):472-481. doi:10.5694/mja2.50598.
  6. Australian and New Zealand Intensive Care Society (ANZICS). COVID-19 Guidelines. https://www.anzics.com.au/wp-content/uploads/2020/10/ANZICS-COVID-19-Guidelines_V3.pdf. Version 3. Published [2021 Oct 20]. Accessed [2021 March 17].
  7. European Resuscitation Council. Lesson 2 - COVID-19: A PANDEMIC. https://cosy.erc.edu/en/online-course preview/356a192b7913b04c54574d18c28d46e6395428ab/index#/lessons/jj1cC_ffuX8CdtrC7CilsQvIMusPGoLP. Accessed [2021 Mar 1717].
  8. Cann C, Hampson MA, Wilkes AR, Hall JE. The pressure required to force liquid through breathing system filters. Anaesthesia. 2006;61(5):492-497. doi:10.1111/j.1365-2044.2006.04581.x.
  9. Wilkes AR. The ability of breathing system filters to prevent liquid contamination of breathing systems: a laboratory study. Anaesthesia. 2002;57(1):33-39. doi:10.1046/j.1365-2044.2002.02091.x.
  10. Wilkes AR. Breathing System Filters. Br J Anaesth. 2002;2(5):151-154. https://doi.org/10.1093/bjacepd/02.05.151.
  11. Speight S, Bennett AM, Lever MR, Benbough J. Efficacy of a pleated hydrophobic filter as a barrier to mycobacterium tuberculosis transmission within breathing systems. Centre for Applied Microbiology and Research (CAMR). 1995.
  12. Vezina DP, Trépanier CA, Lessard MR, Gourdeau M, Tremblay C, et al. An in vivo evaluation of the mycobacterial filtration efficacy of three breathing filters used in anesthesia. Anesthesiology. 2004;101(1):104-109. doi:10.1097/00000542-200407000-00017.
  13. Ball PR, Sanders D. Viral Removal Efficiency of the Pall Ultipor Breathing System Filter. Pall Technical Report. 1989.
  14. Leijten DTM, Rejger VS, Moulton RP. Bacterial contamination and the effects of filters in anaesthetic circuits in a simulated patient model. J Hosp Infect. 1992;21(1):51-60.
  15. Ball PR, Sanders D. Viral Removal Efficiency of the Pall Ultipor Breathing System Filter. Pall Technical Report. 1989.
  16. Heuer JF, Crozier TA, Howard G, Quintel M. Can breathing circuit filters help prevent the spread of influenza A (H1N1) virus from intubated patients? GMS Hyg Infect Control. 2013;8(1):Doc09. Published 2013 Apr 29. doi:10.3205/dgkh000209.
  17. Lloyd G, Howells J. Barriers to Hepatitis C Transmission within Breathing Systems: Efficacy of a Pleated Hydrophobic Filter. Centre for Applied Microbiology and Research (CAMR). 1997.
  18. Lloyd G, Howells J. Efficacy of a Pleated Hydrophobic Filter as a Barrier to Human Immunodeficiency Virus Transmission within Breathing Systems. Centre for Applied Microbiology and Research (CAMR). 1997.
  19. Rosales M, Dominguez V. 2nd International Conference on Prevention of Infection, Nice, France. 1992.
  20. Miorini T, Wille B. Hygienemassnahmen fuer Narkose- und Beatmungszubehoer. Krankenhaus-Hygiene und Infektionsverhuetung. 1990;12 (24).
  21. Chen Z, Capewell A. Retention Characteristics of Pall Breathing System Filters for Aqueous Solutions of Allergenic Natural Latex Rubber Proteins. Pall Technical Report BB136. 2000.
  22. Capewell A. Prion Retention Properties of Pall Ultipor 25 Breathing System Filters. Pall Technical Report BB151. 2004.
  23. Hanover JJ, et al. The effectiveness of the Pall BB25A HME filter during extended use of an anesthesia circuit. (abstract) AANA. 1999;67(5):448.

Author bio

catherine-kane-headsho



Catherine Kane, RN, BSN – Clinical Specialist ICU

Catherine provides clinical support to sales and marketing teams at Cytiva on a full range of products including filters for mechanical ventilation, surgical and medical gas applications, and IV drug delivery systems. Catherine holds a Bachelor of Science in Nursing from the University of St. Francis in Joliet, IL with a background in inpatient nursing and clinical research.