Oxygen Therapy and Ventilation for COVID-19
What is Oxygen Therapy and Ventilation and Why is it 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.
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 method 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.
Types of Oxygen Therapy and Ventilation Equipment and Supplies
Supplemental Oxygen Therapy with High-flow nasal cannula (HFNC), heated humidified high-flow (HHHF) therapy or high-flow nasal oxygen (HFNO). These approaches are designed to deliver high oxygen flow rates with heated humidification to a non-intubated patient. Vital sign monitoring and pulse oximetry are critical for patients receiving supplemental oxygen to assess stabilization, or the need to prepare for additional respiratory support.
Non-Mechanical (non-invasive) Ventilators. If high-flow supplemental oxygen is not adequate, patients may need more advanced ventilation support. Non-mechanical (non-invasive) ventilation can be used for early intervention of respiratory failure and for patients with mild to moderate respiratory failure. The non-invasive ventilators, mainly bilevel continuous CPAP (BiPAP) devices and continuous positive airway pressure (CPAP devices) are alternatives to invasive ventilation, designed to apply continuous positive airway pressure to a non-intubated patient. BiPAP devices are programmed with two distinct pressures, one for inhaling and one for exhaling which allow the patient to get more air in and out of their lungs. (note: The effectiveness of the treatment is closely related to the proper sealing of the nasal or oral-nasal mask to the face.) CPAP devices are set at one single pressure and therefore require modification to convert to bilevel devices in an appropriate way. If the clinicians and bioengineers have sufficient expertise in this area, they should still consider the proper face sealing.
Mechanical Ventilators (Invasive). These devices are designed to provide temporary ventilatory and respiratory assistance to adult and pediatric patients 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
Airway Management. 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.
- 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.
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References and Acknowledgments
(1) World Health Organization: Clinical management of severe acute respiratory infection (SARI) when COVID-19 disease is suspected: Interim guidance, March 2020. Accessed here)
(2) 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 herecessed here