Authors: Jamie Allen, DO, Chief Resident, Emergency Medicine Residency, Lehigh Valley Health Network; Susan R. Wilcox, MD, FACEP, Division Chief, Critical Care, Department of Emergency Medicine, Associate Professor of Emergency Medicine, Harvard Medical School, Associate Chief Medical Officer, Boston MedFlight; and Nicholas Johnson, MD, FACEP, Assistant Professor Emergency Medicine, Adjunct Assistant Professor Division of Pulmonary, Critical Care, and Sleep Medicine, Associate Program Director, Critical Care Medicine Fellowship.
The recommendations included in this section are sourced from the NIH COVID-19 Treatment Guidelines.
Treatment of hypoxemia
High-flow nasal cannula (HFNC)
HFNC is the preferred noninvasive method of oxygenation for patients who have failed treatment with conventional oxygen via nasal cannula or a nonrebreather mask. HFNC has been shown to decrease ICU mortality and intubation rates compared to noninvasive positive-pressure ventilation (NIPPV).
Noninvasive Positive-Pressure Ventilation (NIPPV)
When endotracheal intubation is not indicated, a closely monitored trial of NIPPV for adults can be completed when HFNC is unavailable.
- NIPPV has been shown to increase the risk of nosocomial transmission of COVID-19. Use a negative-pressure room whenever possible.
Mechanical ventilation
There is no evidence that mechanical ventilation for patients with COVID-19 should differ from the ARDSnet-based guideline for patients with hypoxemic respiratory failure from other causes.
- Use a higher positive end-expiratory pressure (PEEP) strategy over a lower PEEP strategy.
Considerations for mechanically ventilated COVID-19 patients
Rapid sequence intubation
- Perform intubation in a negative-pressure room whenever possible.
- Avoid bag-valve-mask (BVM) ventilation whenever possible.
- If BVM ventilation is required post intubation, fully inflate the cuff and use a viral filter prior to bagging or connecting the ventilator.
- Use of a viral filter on the BVM and in the ventilatory circuit is strongly recommended.
Sedation
Sedation of COVID-19 patients does not differ significantly from sedation of other patients who require mechanical ventilation secondary to severe ARDS.
- Propofol
- Induces QTc prolongation.
- Caution should be used in patients who are also receiving azithromycin.
- Caution should be used with prolonged propofol infusions to avoid propofol infusion syndrome.
- Benzodiazepines
- Caution should be used with lorazepam and diazepam infusions to avoid propylene glycol toxicity (eg, unexplained metabolic acidosis, an elevated anion gap, hyperosmolality, and then clinical deterioration).
- Dexmedetomidine
- Dexmedetomidine is not recommended as the initial sedative of choice, or at all (preferred when sedation is needed for <24 hours).
- It may be suitable for patients who are undergoing ventilator weaning and breathing trials.
Analgesia
Like with any sedated patient, analgesia must be ensured in COVID-19 patients. Vital signs such as tachycardia or hypertension can indicate inadequate analgesia. In patients who require ongoing neuromuscular blockade for protective ventilation, do not neglect adequate analgesia. Options for analgesia for COVID-19 patients do not differ significantly from options for other critically ill patients and include fentanyl, hydromorphone, and ketamine, among others.
Paralytics
For patients who are sedated but remain dyssynchronous with a ventilator, intermittent boluses or continuous infusion of neuromuscular blocking agents can be used to facilitate protective lung ventilation. Adequate deep sedation must be given to all paralyzed patients.
- Rocuronium: a nondepolarizing agent with an onset of 1 minute and a recovery time of 30 to 40 minutes
- Vecuronium: a nondepolarizing agent with an onset of 2 to 3 minutes and a recovery time of 30 to 45 minutes
- Cisatracurium: a nondepolarizing agent with an onset of 5 to 7 minutes and a recovery time of 40 seconds to 5 minutes. It is metabolized through Hofmann degradation and should be used in the setting of liver or renal dysfunction.
Proning
- Awake prone positioning can be used for patients with persistent hypoxia who are on HFNC and do not meet the criteria for intubation. Do not use awake prone positioning to avoid intubation in patients who would otherwise meet the criteria for mechanical ventilation.
- Prone positioning for nonintubated patients can be done in cycles of 2 to 4 hours (as tolerated), with brief periods in the supine position for comfort.
- The use of awake prone positioning as a rescue therapy for refractory hypoxemia to avoid intubation in patients who otherwise meet the indications for intubation and mechanical ventilation is not recommended.
- For mechanically ventilated adults with COVID-19 and refractory hypoxemia, prone ventilation for 12 to 16 hours per day can be used.
- This method improves oxygenation through improved ventilation/perfusion (V/Q) matching and keeps alveoli open and evenly distributed at end expiration to avoid ventilator-induced lung injury.
- It is beneficial for patients with moderate to severe ARDS (P/F ratio <150).
- Multiple complications are associated with proning (eg, device dislodgement, difficulty performing procedures, facial edema, skin breakdown, labor intensive).
- Contraindications include, but are not limited to:
- Untrained staff;
- Increased intracranial pressure;
- Increased abdominal pressure;
- Abdominal and chest wounds;
- Cervical spine injury;
- Extreme obesity; and
- Hemodynamic instability.
Treatment of hemodynamic instability
COVID-19 can present with multiple shock phenotypes.1 As such, other potential causes of hemodynamic instability should be addressed based on clinical assessment; these causes can include, but are not limited to, pulmonary embolism, myocardial infarction, hemorrhage, and septic shock from other etiologies. If septic shock is suspected, additional workup should be completed per the Surviving Sepsis Campaign guidelines.
Monitoring and fluid resuscitation
As with any patient with signs of shock, ensure that the patient with COVID-19 is adequately resuscitated. Use objective data such as point-of-care ultrasound evaluation of the inferior vena cava, cardiac output, or pulse pressure variation to assess volume status. The initiation of balanced crystalloid solution such as lactated Ringer should be weighed against the risk of worsening hypoxemia from volume overload.
Vasopressor therapy in COVID-19 patients
- Patients who require vasopressor support should have an arterial line placed.
- Norepinephrine remains the first-line agent for septic shock.
- Second-line therapy includes vasopressin (to raise MAP or decrease the norepinephrine dose) or epinephrine (to maintain MAP >60-65 mm Hg) added to norepinephrine.
- Epinephrine is recommended as the first-line agent for patients with decreased cardiac output or bradycardia.
- Dobutamine can be used for patients with cardiac dysfunction and hypotension that is refractory to other vasopressor support.
- NIH guidelines recommend against the use of dopamine for renal protection.
Corticosteroids
- Dexamethasone 6 mg/day for up to 10 days for hypoxemic patients (RECOVERY trial)
- If already receiving stress-dose hydrocortisone for shock (50 mg every 6 hours), there is no need to add dexamethasone.
- If a course of corticosteroids was recently completed, low-dose corticosteroid therapy is indicated.
Extracorporeal membrane oxygenation for COVID-19 patients
- Recent mortality data on patients with COVID-19 who were treated with extracorporeal membrane oxygenation (ECMO) are mixed. Controlled trials are lacking as well.2-4 At this time, the efficacy of ECMO for these patients is unclear. An ECMO center should be contacted early if a patient who may be a candidate for ECMO presents to the emergency department.
- Try adjunctive measures first, including proning (unless contraindicated), neuromuscular blockage, high PEEP ventilation, and recruitment maneuvers. If adjunctive measures fail to improve oxygenation, the patient has no contraindications to ECMO, and any of the following are present, use EMCO:
- P/F ratio <80 for more than 6 hours
- P/F ratio <50 for more than 3 hours
- pH <7.25, with PaCO2 >60 mm Hg for more than 6 hours
- Contraindications: terminal disease, severe CNS damage, do-not-resuscitate status, and advanced directives that state the patient refuses such therapy.
- More information is available from the Extracorporeal Life Support Organization (ELSO).
Pharmacotherapies
The NIH recommends against the initiation of broad-spectrum antibiotics in isolated COVID-19 infection to mitigate the side effects of antimicrobial therapies. Immunomodulators for COVID-19 should be initiated within the first 24 hours of care, typically in the inpatient setting. If transfer delays are anticipated to lead to a prolonged emergency department stay, see the NIH COVID-19 Treatment Guidelines for initial pharmacologic treatments.
References
- Hollenberg SM, Safi L, Parrillo JE, et al. Hemodynamic profiles of shock in patients with COVID-19. Am J Cardiol. 2021 Aug 15;153:135-139. doi: 10.1016/j.amjcard.2021.05.029
- Alessandri F, Di Nardo M, Ramanathan K, Brodie D, MacLaren G. Extracorporeal membrane oxygenation for COVID-19–related acute respiratory distress syndrome: a narrative review. J Intensive Care. 2023 Feb 8;11(5). doi: 1186/s40560-023-00654-7
- Bertini P, Guarracino F, Falcone M, et al. ECMO in COVID-19 patients: a systematic review and meta-analysis. J Cardiothorac Vasc Anesth. 2022 Aug;36(8):2700-2706. doi: 10.1053/j.jvca.2021.11.006
- Ling RR, Ramanathan K, Sim JJL, et al. Evolving outcomes of extracorporeal membrane oxygenation during the first 2 years of the COVID-19 pandemic: a systematic review and meta-analysis. Crit Care. 2022 May 23;26(147). doi: 1186/s13054-022-04011-2