In early 2020, countries around the world found they needed more ventilators to help patients critically ill with COVID-19. We look at the different types of ventilator and why it is important for the right type of ventilator to be used for critical patients.

As global medical authorities dealt with the COVID-19 pandemic, it soon became apparent that many countries had insufficient supplies of critical care ventilators to successfully cope with the threat. Responses varied, from the idiosyncratic - the TV medical drama donating its working set props - to the more straightforward - a government calling on manufacturers to switch all production to ventilators.1

While these approaches were understandable in the early days of the pandemic, the results were not always successful. It has been reported that several countries spent large sums on inappropriate ventilators.2 This was not just financially damaging but it could also, potentially, result in further damage to the patient or even death.

Types of ventilator

Critical care patients need a ventilator that is specifically designed and tested for use in the most life-threatening situations.

Ventilators come in a variety of different types. These can be broadly split into ventilators for home use and ventilators for clinical use. The simplest machines are those that can be used in the home:

  • Continuous positive airway pressure (CPAP) - helps with sleep apnoea, etc.
  • Ventilatory support equipment - offers basic oxygen (O2) support

Ventilators for clinical settings are more technical and can be broadly split into emergency and critical care. While both types of ventilator need to be operated by trained medical staff, the former must be able to safely operate in a variety of different environments, for example, in emergency vehicles or at altitude if they are in an air ambulance.

Critical care ventilators

Critical patients being treated for COVID-19 needed access to the most advanced form of ventilator - the critical care ventilator. All ventilators primarily deliver O2 to a patient, but the way in which this is achieved can have a profound effect upon the outcome for the patient.

A critical care ventilator must have:

  • Mechanisms to regulate the safe delivery of O2 and the safe removal of carbon dioxide (CO2) to and from the patient. It must incorporate several protective features in order to guarantee the safety of the patient, including pressure limitations, alarms, etc.
  • Ability to connect to a humidifier. This ensures the gas delivered to the patient is safe - moist (100% relative humidity) and at body temperature (37 °C). If dry air is delivered to the patient's lungs, it can cause damage
  • Sensors to measure the expiratory volumes of CO2 to ensure proper intubation - a lack of CO2 may mean there is a problem with the interface between the machine and the patient or a problem with the patient
  • Flow sensor - to see how much gas is entering and/or leaving the patient
  • Interface between the ventilator and the patient - various options are available, including the face mask and endotracheal tube (invasive)
  • Features needed for critically ill patients and the procedures they may undergo - for example, ventilation manoeuvres, recruitment, measurement of patient's inspiratory effort, etc.
Critical care ventilators can also have mechanisms to allow the introduction of aerosolized medication into the air flow.

EU ventilator standards

Implementing Decision (EU) 2020/437, of March 24, 2020, contains a list of harmonized standards for medical devices in support of Directive 93/42/EEC. These include:

  • 8 - EN 794-3:1998+A2:2009 Lung ventilators - Part 3: Particular requirements for emergency and transport ventilators
  • 66 - EN ISO 10651-2:2009 Lung ventilators for medical use - Particular requirements for basic safety and essential performance - Part 2: Home care ventilators for ventilator-dependent patients (ISO 10651-2:2004)

The standard for critical care ventilators is listed as:

  • EN 60601-2-12:2006 Medical electrical equipment - Part 2-12: Particular requirements for the safety of lung ventilators - Critical care ventilators (IEC 60601-2-12:2001)

It should be noted, this standard does not necessarily cover the requirements introduced by Directive 2007/47/EC. Additionally, this standard dates from 2006 and has not kept pace with the speed of ventilator development. Therefore, manufacturers tend to follow newer and more relevant standards:

  • ISO 60601-1 - basic safety and essential performance requirements
  • ISO 60601-1-2 - EMC requirements

Ventilator evaluations must be made in all conditions to ensure the correct amount of O2 is always delivered to the patient:

  • Under 50ml - new-born
  • 50ml to 300ml - child
  • Over 300 ml - adult

IEC 60601-1-2 also contains the frequency with which ventilation should occur, in accordance with the patient category.

ISO/IEC 80601-2-12

Recently revised, this standard provides the basic safety and essential performance requirements for critical care ventilators. Medical devices that conform to this standard have been shown to work safely for both the patient and the operator in a wide variety of situations, including rough treatment tests and mains electricity failure tests. This is a comprehensive standard which conforms to current ventilator technologies. Manufacturers are advised to conform to this standard to successfully access the European Union market.

SGS solutions

SGS has considerable experience in testing ventilators of all types to ensure they conform to relevant standards. In the end, a product is only trusted because it's tested.

Our state-of-the-art laboratories offer testing and certification to a wide variety of global standards, including:

  • International CB Certification
  • North America Listed Mark
  • EU CE Certification
  • USA FDA Registration
  • Brazil INMETRO Certification
  • IEC/EN 60601-1
  • IEC/EN 60601-1-2
  • IEC/EN 60601-1-6
  • IEC/EN 60601-1-8
  • IEC/EN 60601-1-12
  • EN ISO 80601-2-12
  • EN 794-3

Learn more about SGS Electrical and Electro Medical Device Testing.

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For more information, please contact:

Antonio Velasco-Mota
Medical Devices Test Engineer
SGS Germany
t: +49 89 78 74 75 441

References

1Coronavirus: Holby City donates ventilators to London Nightingale hospital & Government calls on manufacturers to help make NHS ventilators
2The U.S. has spent billions stockpiling ventilators, but many won't save critically ill COVID-19 patients & Coronavirus: Hundreds of ventilators UK bought from China 'are wrong type and could kill patients if used'

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SGS SA published this content on 20 January 2021 and is solely responsible for the information contained therein. Distributed by Public, unedited and unaltered, on 20 January 2021 08:15:02 UTC