Sandbox:Javaria
Mechanical ventilation
- The COVID-19 respiratoty complications that may require mechanical ventilation include: COVID-19-associated pneumonia, COVID-19-associated acute respiratory distress syndrome and COVID-19-associated respiratory failure.
Ventilatory support
Supplemental Oxygen
- Surviving Sepsis Campaign has the following recommendations regarding the use of supplemental oxygen in COVID-19 patients:[1]
- It is strongly recommended (with moderate-quality evidence) to start the supplemental oxygen if the Spo2 is < 90% in adults. A weak recommendation states starting the supplemental oxygen at < 92% saturation.
- In COVID-19 positive adult patients with acute hypoxemic respiratory failure on supplemental oxygen therapy, Spo2 should be maintained no higher than 96% (strong recommendation by Surviving Sepsis Campaign). This based upon the systematic review and meta-analysis of 25 RCTs that showed a linear association between the death risk and higher Spo2 targets.
High Flow Nasal Cannula (HFNC)
- Also known as high flow nasal oxygen (HFNO) or Heated humidified high-flow (HHHF) therapy.
- Surviving Sepsis Campaign has the following recommendations regarding the use of HFNC in COVID-19 patients:[1]
- In COVID-19 positive adult patients with acute hypoxemic respiratory failure despite supplemental oxygen therapy, a weak recommendation suggests using HFNC over conventional oxygen therapy. A systematic review and meta-analysis of 9 RCTs showed that High Flow Nasal Cannula (HFNC) reduces the need for intubation.
- A weak recommendation (low-quality evidence) also prefers using HFNC over Non-invasive positive pressure ventilation (NIPPV). It is possibly due to reduced mortality and decreased intubation risk, as proved by a RCT and a meta-analysis respectively. Patient comfort better oxygenation with HFNC than NIPPV is also one of the considering factors.[2]
- Patient should be monitored closely and intubated in the event of decompensation.
Non-Invasive Positive Pressure Ventilation
- Non-invasive positive pressure ventilation (NIPPV) is a technique utilized for delivering mechanical ventilation without the use of endotracheal intubation or tracheostomy. It can be administered through a face mask, nasal mask, or a helmet.
- Many patients who develop ARDS receive a trial of non-invasive positive pressure ventilation (NIPPV) before intubation for mechanical ventilation before they clinically deteriorate or become unable to maintain adequate oxygenation.
- Studies from China reported (4% to 13%) of COVID-19 patients to have received non-invasive positive pressure ventilation (NIPPV).[1]
Invasive mechanical ventilation The Chinese CDC reports the case-fatality rate to be higher than 50% in patients who received invasive mechanical ventilation.[3]
Alternative Mechanical Ventilation Strategies
Several specialized modes of mechanical ventilation have been tested in ARDS, however, none has been proven to carry a morbidity or mortality benefit and should only be considered if oxygenation does not improve with a judicious trial of the first-line mechanical ventilation strategies as outlined by the ARDS Network.[4]
- High-frequency oscillatory ventilation (HFOV) may improve oxygenation in patients with moderate to severe ARDS and severe refractory hypoxemia, however, initiation of HFOV early in the course of ARDS (i.e., prior to low tidal volume/high PEEP mechanical ventilation) has been associated with increased mortality compared to lower tidal volume/high PEEP ventilation[5][6]
- Airway pressure release ventilation (APRV) appears to be safe in ARDS, and may be associated with reduced paralytic and sedative use as well as an increase in the number of ventilator-free days[7][8]
Recruitment Maneuvers
A recruitment maneuver is the application of very high (up to 40 cm H2O) positive airway pressure to open collapsed alveoli, thereby reducing shunting, decreasing V/Q mismatching, and improving gas exchange. The decision to apply recruitment maneuvers must take into account various factors including the extent of lung injury (due to the risk of causing volutrauma through overdistention of stiff and inflamed lungs) and patient hemodynamics (due to the risk of further worsening hypotension by impeding venous return to the right heart). Recruitment maneuvers have not been standardized and there are insufficient data to support or discourage their use in ARDS.
Extracorporeal Membrane Oxygenation (ECMO)
There is growing evidence to support the use of extracorporeal membrane oxygenation (ECMO) for severe ARDS that fails to improve despite judicious application of the ARDS Network low tidal volume/high PEEP ventilation strategy.[9][10] ECMO facilitates gas exchange in circumstances where adequate oxygenation and ventilation cannot be achieved through the lungs themselves. There are two main forms of ECMO, both of which have been used successfully in the treatment of severe ARDS:
- Veno-venous (VV)-ECMO: Venous blood is removed through an outflow cannula placed in a large vein (usually the right femoral vein or inferior vena cava) and passed through an oxygenator where gas exchange occurs (CO2 is removed and O2 is introduced) before being returned to the body through an inflow cannula placed in another large vein (usually the right internal jugular vein or superior vena cava)
- Supports gas exchange but does not provide any hemodynamic support
- Veno-arterial (VA)-ECMO: Venous blood is removed through an outflow cannula placed in a large vein (usually the right femoral vein or inferior vena cava) and passed through an oxygenator where gas exchange occurs (CO2 is removed and O2 is introduced) before being returned to the body through an inflow cannula placed in a large artery (usually the right femoral artery or right carotid artery)
- Supports gas exchange and provides hemodynamic support by bypassing the heart completely
The use of ECMO in the treatment of ARDS is an ongoing area of research, and referral to a medical center with ample experience in the use of ECMO for ARDS should be considered for patients with ARDS who are failing traditional management strategies and may be candidates for ECMO. The use of ECMO requires systemic anticoagulation (usually with heparin) and is associated with the risk of major hemorrhage as well as thrombosis. Additionally, the use of VA-ECMO may result in ischemic injury to the limb distal to the site of the inflow cannula (although rates of limb ischemia have been mitigated by the addition of a reperfusion cannula that takes blood from the inflow cannula and delivers it distally to the otherwise-affected limb).
The vascular endothelial injury in CARDS and diverse mortality rates across the world in CARDS patients arbitrates the importance of different mechanical ventilation strategies. Marini et al. suggest
- Lower PEEP: “type L,” characterized by low lung elastance (high compliance), lower lung weight as estimated by CT scan, and a low response to PEEP
- Higher PEEP:
- Lower tidal volume ventilation (6 mL/kg predicted body weight) is associated with reduced mortality and a greater number of ventilator-free days[11]
- Lower tidal volume ventilation should be continued even if the arterial partial pressure of carbon dioxide (PaCO2) rises (this is called permissive hypercapnia)
- Permissive hypercapnia usually results in a drop in blood pH, however, treatment of acidemia (e.g., intravenous administration of sodium bicarbonate or tromethamine) is not indicated if the pH remains at or above 7.15 to 7.20
- Predicted body weight (PBW) in kilograms (kg) may be calculated from height in inches (in) as follows:
- PBW (men) = 50 + 2.3 (height in inches – 60)
- PBW (women) = 45.5 + 2.3 (height in inches – 60)
- Higher positive end-expiratory pressure (PEEP) combined with lower tidal volume ventilation is associated with decreased mortality in patients with moderate or severe ARDS (PaO2/FIO2 ≤ 200)[12]
- Prone positioning for at least 16 consecutive hours each day is associated with improved 28-day and 90-day survival in patients with ARDS and a PaO2/FIO2 ratio < 150 on an FIO2 ≥ 60% and PEEP ≥ 5 mmHg
- Prone positioning is thought to improve oxygenation by improving ventilation/perfusion (V/Q) mismatching via reduced shunting of blood through under-ventilated lung tissue
- Cisatracurium, when started within the first 48 hours of ARDS diagnosis and continued for 48 hours, has been associated with improved 90-day survival, a greater number of ventilator-free days, and a decreased incidence of volutrauma[13]
ARDS Network Mechanical Ventilation Protocol
References
- ↑ 1.0 1.1 1.2 Alhazzani, Waleed; Møller, Morten Hylander; Arabi, Yaseen M.; Loeb, Mark; Gong, Michelle Ng; Fan, Eddy; Oczkowski, Simon; Levy, Mitchell M.; Derde, Lennie; Dzierba, Amy; Du, Bin; Aboodi, Michael; Wunsch, Hannah; Cecconi, Maurizio; Koh, Younsuck; Chertow, Daniel S.; Maitland, Kathryn; Alshamsi, Fayez; Belley-Cote, Emilie; Greco, Massimiliano; Laundy, Matthew; Morgan, Jill S.; Kesecioglu, Jozef; McGeer, Allison; Mermel, Leonard; Mammen, Manoj J.; Alexander, Paul E.; Arrington, Amy; Centofanti, John E.; Citerio, Giuseppe; Baw, Bandar; Memish, Ziad A.; Hammond, Naomi; Hayden, Frederick G.; Evans, Laura; Rhodes, Andrew (2020). "Surviving Sepsis Campaign: Guidelines on the Management of Critically Ill Adults with Coronavirus Disease 2019 (COVID-19)". Critical Care Medicine. 48 (6): e440–e469. doi:10.1097/CCM.0000000000004363. ISSN 0090-3493.
- ↑ Frat, Jean-Pierre; Thille, Arnaud W.; Mercat, Alain; Girault, Christophe; Ragot, Stéphanie; Perbet, Sébastien; Prat, Gwénael; Boulain, Thierry; Morawiec, Elise; Cottereau, Alice; Devaquet, Jérôme; Nseir, Saad; Razazi, Keyvan; Mira, Jean-Paul; Argaud, Laurent; Chakarian, Jean-Charles; Ricard, Jean-Damien; Wittebole, Xavier; Chevalier, Stéphanie; Herbland, Alexandre; Fartoukh, Muriel; Constantin, Jean-Michel; Tonnelier, Jean-Marie; Pierrot, Marc; Mathonnet, Armelle; Béduneau, Gaëtan; Delétage-Métreau, Céline; Richard, Jean-Christophe M.; Brochard, Laurent; Robert, René (2015). "High-Flow Oxygen through Nasal Cannula in Acute Hypoxemic Respiratory Failure". New England Journal of Medicine. 372 (23): 2185–2196. doi:10.1056/NEJMoa1503326. ISSN 0028-4793.
- ↑ Wu, Zunyou; McGoogan, Jennifer M. (2020). "Characteristics of and Important Lessons From the Coronavirus Disease 2019 (COVID-19) Outbreak in China". JAMA. 323 (13): 1239. doi:10.1001/jama.2020.2648. ISSN 0098-7484.
- ↑ NIH-NHLBI ARDS Clinical Network Mechanical Ventilation Protocol Summary. "http://www.ardsnet.org/files/ventilator_protocol_2008-07.pdf"
- ↑ Derdak S, Mehta S, Stewart TE, Smith T, Rogers M, Buchman TG; et al. (2002). "High-frequency oscillatory ventilation for acute respiratory distress syndrome in adults: a randomized, controlled trial". Am J Respir Crit Care Med. 166 (6): 801–8. doi:10.1164/rccm.2108052. PMID 12231488.
- ↑ Ferguson ND, Cook DJ, Guyatt GH, Mehta S, Hand L, Austin P; et al. (2013). "High-frequency oscillation in early acute respiratory distress syndrome". N Engl J Med. 368 (9): 795–805. doi:10.1056/NEJMoa1215554. PMID 23339639.
- ↑ Daoud EG (2007). "Airway pressure release ventilation". Ann Thorac Med. 2 (4): 176–9. doi:10.4103/1817-1737.36556. PMC 2732103. PMID 19727373.
- ↑ Daoud EG, Farag HL, Chatburn RL (2012). "Airway pressure release ventilation: what do we know?". Respir Care. 57 (2): 282–92. doi:10.4187/respcare.01238. PMID 21762559.
- ↑ Gattinoni L, Pesenti A, Mascheroni D, Marcolin R, Fumagalli R, Rossi F; et al. (1986). "Low-frequency positive-pressure ventilation with extracorporeal CO2 removal in severe acute respiratory failure". JAMA. 256 (7): 881–6. PMID 3090285.
- ↑ Peek GJ, Mugford M, Tiruvoipati R, Wilson A, Allen E, Thalanany MM; et al. (2009). "Efficacy and economic assessment of conventional ventilatory support versus extracorporeal membrane oxygenation for severe adult respiratory failure (CESAR): a multicentre randomised controlled trial". Lancet. 374 (9698): 1351–63. doi:10.1016/S0140-6736(09)61069-2. PMID 19762075.
- ↑ "Ventilation with lower tidal volumes as compared with traditional tidal volumes for acute lung injury and the acute respiratory distress syndrome. The Acute Respiratory Distress Syndrome Network". N Engl J Med. 342 (18): 1301–8. 2000. doi:10.1056/NEJM200005043421801. PMID 10793162.
- ↑ Briel M, Meade M, Mercat A, Brower RG, Talmor D, Walter SD; et al. (2010). "Higher vs lower positive end-expiratory pressure in patients with acute lung injury and acute respiratory distress syndrome: systematic review and meta-analysis". JAMA. 303 (9): 865–73. doi:10.1001/jama.2010.218. PMID 20197533.
- ↑ Papazian L, Forel JM, Gacouin A, Penot-Ragon C, Perrin G, Loundou A; et al. (2010). "Neuromuscular blockers in early acute respiratory distress syndrome". N Engl J Med. 363 (12): 1107–16. doi:10.1056/NEJMoa1005372. PMID 20843245. Review in: Ann Intern Med. 2011 Jan 18;154(2):JC1-3