Oxygen Therapy and Ventilation for COVID-19
Why is Oxygen Therapy Important for COVID-19
While most people with COVID-19 develop only mild or uncomplicated illness, some patients do develop severe cases and require hospitalization, oxygen support, or admission into intensive care units for ventilation and other interventions for critical care. (1). COVID-19 can cause pneumonia, or in more serious cases, Acute Respiratory Distress Syndrome (ARDS) in which the air sacs in the lungs fill with fluid and oxygen levels decrease. In these more serious cases, patients may require a range of breathing support interventions, starting with supplemental oxygen therapy, or if that does not work, they may require non-invasive or invasive ventilation procedures.
VIA Global Health does not sell all products that would be essential for intensive care units oxygen therapy, anesthesia, ventilation, and airway management and does not offer clinical recommendations on such.
Types of Oxygen Therapy and Ventilation Equipment and Supplies
A complete oxygen system must consist of the following elements: oxygen sources; delivery devices; regulation and conditioning devices; and patient monitoring devices.
- Oxygen concentrators are electrically powered medical devices that concentrate oxygen from ambient air, and then deliver oxygen to the patient through a nasal cannula or prongs. The intended use or clinical purpose is the delivery of low-flow, continuous, clean and concentrated oxygen (> 82%) from room air (21%). (2)
- Oxygen cylinders compress oxygen and medical air cylinders are refillable containers for holding oxygen/medical gases in a high-pressure, non-liquid state. They are fitted with a valve and a pressure regulator, and a flow regulator for supplying oxygen amedical air to other medical devices, or low-pressure supply to the patient if an integral valve is installed. The cylinders are available in various standard sizes with regulators and fittings for all international standards.
Oxygen Delivery Devices
- Nasal oxygen cannula with prongs: These plastic tubes are shaped as two prongs inserted into nasal cavities to deliver supplemental air/ oxygen mixture when connected to an oxygen source. This is a single-use, non-sterile device. The oxygen flow rate and humidification might vary, and vital sign monitoring of the patient monitoring is important, particularly oxygen saturation through pulse oximeters.
- Mask with reservoir bag: Face mask and tubing used to deliver medical oxygen directly to the upper airway of the patient. It allows the administration of a high oxygen concentration.
- Venturi mask: Also known as air-entrainment masks, this device is able to provide total inspiratory flow at a specified fraction of inspired oxygen (FiO2).
Patient Ventilators (Non-Invasive and Invasive)
Although ventilators are used in clinical scenarios and intensive care units beyond the COVID-19 crisis, there are specific clinical guidelines for treatment of critically or severely ill patients in the context of COVID-19.
- High-flow nasal cannula (HFNC) (also known as heated humidified high-flow (HHHF) therapy or high-flow nasal oxygen (HFNO)): This approach delivers high flow rates with heated humidification to non-intubated patients (adult or pediatric). A HFNC can provide a higher flow (up to 50–70 L/min) than a nasal cannula connected to a standard flowmeter (up to approximately 15 L/min) (see above in oxygen delivery section). Additionally, HFNC decreases airway inflammation and reduces the energy expenditure in acute respiratory failure. A specialized flowmeter and a heated humidifier are incorporated into the unit to deliver heated and humidified gases, through a circuit and patient interface and inspired oxygen, FiO2 can be set by the clinician. The effectiveness of the treatment is related to the high flow generated.
Key Considerations for Non-Invasive Ventilators
- The use of non-invasive ventilators must be with very high attention to infection prevention and control, as they are aerosol generating procedures and can be of risk to the health care providers.
- HFNC and CPAP may require extremely large supplies of oxygen.
- Continuous positive airway pressure (CPAP): These devices are intended for non-intubated patients (adult or pediatric) and most commonly used in spontaneously breathing patients who require short-term mechanical assistance. CPAPs can a mixture of air and oxygen at high flow rates and a single set pressure, through a circuit and patient interface (mask).
- Bilevel positive airway pressure (BiPAP/BPAP): Similar to CPAPs, BiPAP devices are intended for non-intubated patients (adult or pediatric) who are spontaneously breathing and require short-term mechanical assistance. However, BiPAPs allow the health care providers to adjust two different pressures, one during the inspiratory phases of breath, and one during expiratory phases of a breath. A higher inspiratory pressure reduces the patient’s breathing effort, and a lower pressure helps to preserve an adequate alveolar volume and prevent collapse of unstable alveolar units during expiration. BiPAPs also require a patient interface, either a nasal or oral-nasal.
Ventilator for intensive care unit: These devices are designed to provide temporary ventilatory and respiratory assistance to patients (adult and pediatric) who cannot breathe on their own or who require assistance to maintain adequate ventilation. The mixed, heated and humidified gas is delivered to the patient using a double-limb breathing circuit (one for inspiratory and one for expiratory phases). The user interface has different parameters which can be controlled by the user and displayed, typically: fraction of inspired oxygen (FiO2); trigger; respiratory rate (RR); positive end-expiratory pressure (PEEP). Though they may include an internal air compressor, they will need EITHER a low-flow oxygen source, such as an oxygen concentrator, OR a high-flow oxygen source such as an oxygen cylinder or piped oxygen). In addition to specific training and skills in managing mechanical ventilation, this procedure first requires intubation, an aerosol generating procedure (AGP). This means that adequate preparation, communication, and infection prevention and control (IPC) measures are important for the safety of the patient and the healthcare workers. See section below for airway management devices.
There are ventilators for transport or sub-acute care are highly portable and lightweight but must have significant battery life (at least 4 hours), should minimize oxygen consumption, and not require a compressed air gas source so they can be used in different areas of a hospital or elsewhere. These are typically simpler and lower cost, but still require adequate training and IPC measures.
Key Considerations for Invasive Ventilators
- Invasive ventilators require highly trained medical staff to perform the intubation and to manage the appropriate pressure settings, controls and alarms.
- There are also infrastructure requirements related to environmental temperature and humidity control, and safety measures for high-pressure oxygen and air sources
- Adequate equipment maintenance and decontamination procedures are essential for ensuring proper functioning of equipment.
- Many ventilators require oxygen pressure exceeding what can realistically be provided through a concentrator or other low-pressure source.
Airway management includes (but is not limited to) tracheal intubation for ventilation, cardiac arrest, anesthesia, and tracheal extubation that might be necessary in the clinical care of very ill patients with COVID-19. To minimize risks to patients and to healthcare workers, airway management procedures should be safe, accurate, and quick. Selecting the appropriate procedure and product depends on the skills of the clinician, available resources, and the infrastructure of the facility.
- Videolaryngoscopes or Conventional Laryngoscopes. Laryngoscopy should be undertaken with the device most likely to achieve prompt first‐pass tracheal intubation; video laryngoscopes enable greater visualization and maximize the distance between the patient and the health care provider, and may be preferable if the airway manager has been trained in their use. The use of either video or conventional laryngoscope should be chosen by the clinician according to their skills and the clinical infrastructure. (Shop Laryngoscopes Now)
- Reusable versus Disposable Blades for Laryngoscopes. The choice between reusable and disposable (single-use) blades will again depend on the health care workers and their clinical environment. Infection prevention and control (IPC) measures and decontamination of all medical equipment, including reusable blades, would be an important factor.
- Manual or Electrical Suctioning Devices. These devices may be required to maintain a clear airway and reduce risk of infection.
Patient Monitors: Pulse Oximeters and Multi-Parameter Monitors
Throughout oxygen support or ventilation for the care of a COVID-19 patient, there are two types of patient monitoring devices that are priorities for continuous monitoring of important physiological parameters.
- Pulse oximeters: are devices designed to monitor the haemoglobin oxygen saturation (SpO2) through transcutaneous measurements. These are either handheld, which are portable and battery powered, and can display the the SpO2 value and pulse rate; tabletop oximeters are electrically powered bedside devices that display the SpO2 value, pulse rate, and may also detect other parameters. Fingertip pulse oximeters are portable, and battery-powered device used on a patient’s finger, displaying the SpO2. For more information on pulse oximeters, see our Buyers Guide here
- Multi-parameter patient monitors multiparametric come in a range of basic, intermediate, and advanced capabilities to continuously measure and display physiological parameters that are important clinical indicators for intensive care units, and for surgeries and post-operative care. There are portable battery-powered patient monitors, as well as bedside versions that rely on electricity supply. The devices will also include patient cables, sensors and accessories, based on the parameters that will be measured by the monitors. (e.g. ECG, blood pressure, heart rate, temperature, respiratory rate and respiratory gas concentrations).
Key Considerations for Selecting Oxygen Therapy and Ventilation Equipment
- Severity of COVID-19-related respiratory illness. Patients with COVID-19 experience the disease with only mild or moderate symptoms, OR with more serious pneumonia, severe pneumonia, and Acute Respiratory Distress Syndrome (ARDS). Although the collective understanding of COVID-19 related illness is changing rapidly, we do know that bilateral pneumonia is a common characteristic of severe COVID-19, and adequate oxygen therapy, or ventilatory support is crucial for patient outcomes. The appropriate method will depend on the severity of the disease, the resources and infrastructure available in the facility, and the clinical assessment of the health care team.
- Mechanical (Invasive) versus Non-Mechanical Ventilation (Non-invasive). All types of ventilation require well-trained clinical staff to ensure safety of the patient, as well as to minimize the risk of transmission of the virus. The selection of ventilation methods will depend on the severity of the patient’s illness, the oxygen source, the availability of equipment, consumables, and accessories, and the skills of the health care workers. Mechanical ventilators are the most complex and for the most critically ill patients, whereas supplemental oxygen therapy with nasal cannula might be sufficient for less severely ill patients.
- Infection Prevention and Control (IPC) and Protecting Health Care Workers. Because procedures during airway management and in the intensive care unit (ICU) generate aerosols, the risk of transmission to health care workers is high. Therefore, proper ventilation, oxygen therapy, and airway management in the context of COVID-19 will require more than just the technical aspects of the procedure itself, and must include important steps in preparation, protection of healthcare workers, decontamination, and clear communication protocols prior to, during, and following the procedure.
- Accessories and Consumables. Managing oxygen flow, ensuring availability of the appropriate patient interface and breathing circuits, decontaminating reusable parts, are all important when selecting the appropriate ventilation technique and equipment. Product pages should indicate what is included and anything related to proprietary or compatible accessories.
- Oxygen Sources and Flow Regulation. Some facilities have piped oxygen, while others rely on oxygen concentrators or cylinders. The type of oxygen therapy and ventilation support may depend on the source of oxygen and the ability to effectively manage flow and concentration. Visit our additional Buyers Guides here
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- World Health Organization: Clinical management of severe acute respiratory infection (SARI) when COVID-19 disease is suspected: Interim guidance, March 2020. Accessed here)
- Priority medical devices list for the COVID-19 Response and Associated Technical Specifications. Interim Guidance. World Health Organization. November 2020. Accessed here
- Dondorp, A., Hayat M. et al. Review Article. Respiratory Support in Novel Coronavirus Disease (COVID-19) Patients, with a Focus on Resource-Limited Settings. Am. J. Trop. Med. Hyg., 00(0), 2020, pp. 1–7doi:10.4269/ajtmh.20-028. Accessed here