With the COVID-19 pandemic spreading, medical organizations are steadily releasing recommendations to healthcare workers. Here is a quick overview of the current guidance for management of acute respiratory failure (ARF) in COVID-19 patients.
Although high velocity therapy is a form of noninvasive ventilation (NIV), the below summaries use the term high velocity therapy/HFNC to better reflect the original guidelines’ distinctions between open systems delivering high flow oxygen to the nose (high velocity/HFNC) and pressure-and-mask-based systems (NiPPV).
At this time, the CDC hasn’t released specific guidance, but is sharing the recommendations of the World Health Organization and the Society of Critical Care Medicine below.
The guidelines (revised on March 13, 2020) call for high velocity/HFNC or NiPPV to be used only in selected patients with hypoxemic respiratory failure.
- MERS Limited data suggest that patients treated with NiPPV for other viral infections have a high risk of treatment failure.
- Patients treated with high velocity/HFNC or NiPPV should be closely monitored for clinical deterioration. In the case of high velocity/HFNC the guidelines call for a one-hour trial on the therapy to determine whether it needs to be discontinued.
- The use of high velocity/HFNC can proceed with caution. The modality is reported to reduce the need for intubation compared to standard oxygen therapy.
The journal for SCCM (Critical Care Medicine), has posted guidelines jointly with the Intensive Care Medicine journal, including an infographic algorithm.
- Suggests use of high velocity/HFNC in management of Acute Hypoxemic Respiratory Failure when conventional oxygen therapy fails.
- Use of high velocity/HFNC suggested over the use of noninvasive positive pressure ventilation (NiPPV) for these patients.
- Trial of NiPPV suggested with close monitoring and short-interval assessments if high velocity/HFNC not available and the patient didn’t need urgent intubation.
- Close monitoring recommended on any modality in case of worsening condition requiring intubation.
- Calls for high velocity/HFNC equipment setup on all critical patients.
- Recommend FiO2 of up to 0.9-1.0 to maintain saturation.
- High velocity/HFNC can be used either as a ‘ceiling option’ or a precursor to CPAP/NiPPV. They urge caution due to possible droplet formation.
- When using CPAP/NiPPV, first choice is helmet interface without humidification, up to 15-20 cmH2 CPAP with a mask is second choice and NiPPV with a mask/filter is third choice.
Provides an expert consensus paper on preventing nosocomial transmission during respiratory care for critically ill patients with COVID-19. They acknowledge that respiratory treatment of the patients includes high-risk factors for nosocomial transmission (at writing, 1700 bedside clinicians had been infected) and call for specific interventions to mitigate the risk.
- Use of Personal Protective Equipment (PPE), filters for ventilators and bag-valve-mask resuscitators, and masks for bronchoscopy.
- Specifically call for use of a simple surgical mask over the face of the patient, covering the mouth and nose with the high velocity/HFNC cannula in place. Vapotherm’s science team recently conducted modeling to test the effectiveness of this intervention with high velocity.
- Recommend securing HFNC system tubing if it has the capability to disengage at the nosepiece (Vapotherm high velocity therapy uses a fused single-piece cannula without the possibility to thus disengage).
- For technologies with heavy tubing sets, recommend securing the tubing so as not to disturb the surgical mask.
The German Society for Internal Intensive Care Medicine and Emergency Medicine, the German Interdisciplinary Association for Intensive Care and Emergency Medicine, the German Society for Pulmonology and Breathing Medicine, the German Society for Anesthesiology and Intensive Care, and the ARDS Network of Germany issued guidelines on the intensive care therapies for patients with COVID-19.
- Recommend both NiPPV and high velocity/HFNC to maintain SpO2≥90%.
- Recognize that both modalities can lead to aerosol generation but cite research6,7 supporting safe administration so long as the interface is properly applied in the case of NiPPV.
- Call for use of proper PPE and FFP2.
- Caution that for severe hypoxaemia (PaO2/FiO2 ≤ 200 mmHg) intubation/mechanical ventilation may be preferable to avoid increased risk of aerosol exposure during emergency intubation.
A management paradigm was proposed by a French team.
- Priority placed on PPE and transmission control.
- Possible admissions to the ICU should be considered on a daily basis.
- Care to COVID-19 patients should not be limited, but procedures which are likely to pose a transmission risk (e.g., ECMO, BAL, transport) must be discussed.
- Note that ARDS is often associated with shock and multiple organ failure. High velocity/HFNC is specifically recommended in a treatment example, between standard oxygen cannula and mechanical ventilation.
A COVID-19 working group of clinicians published the ANZICS guidelines in the context of caring for COVID-19 patients in the ICU.
- Recommend high velocity/HFNC for routine use as long as staff uses PPE and practice infection control precautions. Note that the transmission risk with proper fit is low.
- Preferred use of negative pressure rooms when high velocity/HFNC is in use.
- Do not recommend NiPPV for routine use as the transmission risk, especially with a poor mask fit, may be higher.
- Call for mechanical ventilation in cases of acute respiratory failure.
Given the scope of the pandemic, a team at the DoD released their “COVID-19 Practice Management Guide” on March 23, 2020. These highlights regard adult patient recommendations.
- Call for supplemental oxygen for patients in respiratory distress, hypoxemia or shock. Recommend a target SpO2 of 92-96%.
- Recommend consideration of early intubation for patients that require 5-6 L/min consistently to maintain target saturation. Rapid sequence intubation (RSI) is recommended.
- If intubation/mechanical ventilation resources are limited or unavailable, they recommend high velocity/HFNC or a facemask with a reservoir bag at 10-15L/min if the patient is in critical condition.
- They do not recommend NiPPV due to higher risk of transmission, and higher need for staff intervention. Note that if high velocity/HFNC fails, NiPPV should be avoided and intubation should be considered.