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COVID-19: Respiratory treatment in critical care – recommendations

Article

Author: Munir Karjaghli

Date of first publication: 23.03.2020

Last change: 15.06.2020

Mechanical ventilation guidelines - phenotypes A and B
In this article we outline the recommendations for the respiratory treatment of COVID-19 patients drawn from recent literature and guidelines issued by various organizations worldwide. They reflect the status as at the date of last change shown here.
COVID-19: Respiratory treatment in critical care – recommendations

Fundamentals

Choices regarding supplemental oxygen delivery and providing invasive respiratory support are crucial, and may impact outcomes as well as the saturation of critical care beds (Marini JJ, Gattinoni L. Management of COVID-19 Respiratory Distress. JAMA. 2020;323(22):2329-2330. doi:10.1001/jama.2020.68251​). The following action is essential:

  • Ensure airborne protection for every phase/step in critical care settings (wherever possible)
  • Anticipate needs, maximize first-pass success

SpO2

Target SpO2 92%–95%, higher for emergency patients. Use supplemental oxygen therapy at 5 l/min and higher. Hygiene precautions are essential: HFOT (high flow oxygen therapy) and leaking NIV (noninvasive ventilation) interfaces may generate contaminated aerosols.

Caution with HFOT and NIV!

Before deciding to apply noninvasive therapies such as HFOT or NIV, consider their benefits versus the risk of airborne diffusion. These therapies may result in the widespread dispersion of exhaled air and infectious aerosols.

Known high failure rates in COVID-19 patients may be an additional argument against treating them with noninvasive therapies. Use HFOT and NIV in selected patients only, and closely monitor the patient situation for deterioration. Patients receiving a NIV trial should be in a monitored setting and cared for by experienced staff capable of endotracheal intubation, in case the patient deteriorates acutely or does not improve after about one hour. Patients with hemodynamic instability, multi-organ failure, or an abnormal mental status should not receive NIV.

Intubation

When deciding whether to perform an endotracheal intubation:

  • Adopt Early Warning Scores for intubation/quod vitam prognosis (consider DNR cases)
  • Identify an isolated room (negative pressure environment if possible)

It is preferable to perform intubation as an elective procedure, rather than waiting until it is an emergency (greater patient risk).

If the decision is made to inubate, ensure the minimum number of team members:

  • The most expert team member should perform the intubation and advanced airway control/ventilation (wearing PPE)
  • Expert assistant on protocols and devices (doctor/nurse wearing PPE)
  • Second doctor wearing PPE if complex maneuver/difficult airway is expected/planned
  • Doctor available wearing PPE outside the room
  • Observer putting on / taking off PPE outside the room 

Additional considerations for intubation:

  • Consider video laryngoscopy to ensure the highest possible level of hygiene and self-protection.
  • Ensure the duration of pre-oxygenation is sufficient before intubating ARDS patients (5 min with 100% Oxygen, using a face mask with reservoir bag, bag-valve mask, or NIV).
  • Continuous waveform capnography should be used for every tracheal intubation and in all patients dependent on mechanical ventilation unless this is impossible for any reason.

Before applying mechanical ventilation

Before applying mechanical ventilation (MV), consider the following:

  • Bacterial/viral filter on every oxygenation interface (face mask, circuit, endotracheal tube, supraglottic airway devices, introducer, airway exchange catheters, ventilator inspiratory and expiratory outlet)
  • Airway cart ready (disposable devices preferable)
  • Suction: Closed system prepared with tube extension

Phenotypes and ventilation strategy

I.   Carefully identify those patients in need of mechanical ventilation (MV).

II.  Ensure correct phenotyping of patients according to the criteria shown below (proposed by Gattinoni et al.).

III.  Select the ventilation strategy according to the phenotype. 

The P/V Tool® Pro can be used to phenotype patients and assess lung recruitability.  

Phenotypes

Type H phenotype Type L phenotype
High elastance (low compliance) Low elastance
High right-to-left shunt Low ventilation-to-perfusion (V/Q) ratio
High lung weight Low lung weight
High lung recruitability Low lung recruitability

Type H phenotpye

For Type H, apply mechanical ventilation according to the current recommendations for treatment of ARDS patients: 

1. Tidal volume: 4–6 ml/kg predicted body weight

2. Pplat < 30 cmH2O

3. Maintain the driving pressure (Pplat-PEEP) as low as possible (< 14 cmH2O)

4. Permissive hypercapnia

5. Higher PEEP (PEEP ≤ 15 cmH2O) settings may be beneficial in patients with moderate-to-severe ARDS

6. Recruitment maneuvers (RMs) are not routinely recommended in COVID-19 patients

7. RM and higher PEEP >15 can be beneficial in patients with the typical CT pattern of moderate-to-severe ARDS, with alveolar edema, obesity, decrease in chest wall compliance and high potential for lung recruitment

8. Prone positioning should be used only as a rescue maneuver 

9. Avoid unnecessary disconnections of breathing circuits (if needed, put ventilator on standby / clamp endotracheal tube before disconnection) to ensure airborne protection and maintain PEEP

10. Use weaning protocols to reduce the duration of invasive mechanical ventilation, considering the following points:

  • Weaning should be undertaken with caution
  • Make transitions carefully and avoid abrupt changes 
  • Perform spontaneous trials only at the very end of the weaning process
  • Strong spontaneous efforts raise O2 demand, increase edema, and promote P-SILI (patient self-induced lung injury)

11. Follow a conservative fluid management strategy for ARDS patients without tissue hypoperfusion

12. Closely monitor the cardiac function of the patient

Type L phenotype

The following applies for Type L patients:

1. For nonintubated hypoxic patients who are not yet breathless, the first step to reverse hypoxemia is through an increase in FiO2

2. For patients with dyspnea, several noninvasive options are available including:

  • High Flow Nasal Cannula (HFNC)
  • Continuous Positive Airway Pressure (CPAP)
  • Noninvasive Ventilation (NIV)

Ensure close monitoring if noninvasive ventilation is used, as it may be associated with high failure rates and delayed intubation in a disease that typically lasts a few weeks.

3. Consider measurement (or estimation) of the work of breathing, by means of:

  • Inspiratory esophageal pressure swings
  • Surrogate measures of work of breathing, such as the swings of central venous pressure, or clinical detection of excessive inspiratory effort
  • P0.1 and P occlusion (if the patient is intubated) 
     

4. If inspiratory pleural pressures swings are greater than 15 cmH2O, the risk of lung injury increases and intubation should therefore be performed as soon as possible

5. Early intubation may avert the transition to the Type H phenotype

6. Adjust VT to 7-8ml/kg and RR to achieve an acceptable gas exchange. The high compliance results in tolerable strain without the risk of VILI 

7. Prone positioning should be used only as a rescue maneuver8. PEEP should be reduced to 8-10 cmH2O, given that the recruitability is low and the risk of hemodynamic failure increases at higher levels 

Full citations below: (Marini JJ, Gattinoni L. Management of COVID-19 Respiratory Distress. JAMA. 2020;323(22):2329-2330. doi:10.1001/jama.2020.68251​, Papazian L, Aubron C, Brochard L, et al. Formal guidelines: management of acute respiratory distress syndrome. Ann Intensive Care. 2019;9(1):69. Published 2019 Jun 13. doi:10.1186/s13613-019-0540-92​, Kluge, S., Janssens, U., Welte, T. et al. Empfehlungen zur intensivmedizinischen Therapie von Patienten mit COVID-19. Med Klin Intensivmed Notfmed (2020). https://doi.org/10.1007/s00063-020-00674-3).3​, Amato MB, Meade MO, Slutsky AS, et al. Driving pressure and survival in the acute respiratory distress syndrome. N Engl J Med. 2015;372(8):747-755. doi:10.1056/NEJMsa14106394​, World Health Organisation: Clinical management of severe acute respiratory infection (SARI) when COVID-19 disease is suspected: Interim guidance V 1.2 (March 2020)5​, WHO guidelines: https://www.who.int/emergencies/diseases/novel-coronavirus-2019/technical-guidance6​, Sorbello M., Giacinto I. Di ,Bressan F. ,Cataldo R., Cortese G., Esposito C., Falcetta S., Merli G., Petrini F. . COVID-19 Airway Management Rev 1.1, SIAARTI, on behalf of SIAARTI Airway Management Research Group (March 2020)7​, Robba C, Battaglini D, Ball L, et al. Distinct phenotypes require distinct respiratory management strategies in severe COVID-19. Respir Physiol Neurobiol. 2020;279:103455. doi:10.1016/j.resp.2020.1034558​, Cook TM, El-Boghdadly K, McGuire B, McNarry AF, Patel A, Higgs A. Consensus guidelines for managing the airway in patients with COVID-19: Guidelines from the Difficult Airway Society, the Association of Anaesthetists the Intensive Care Society, the Faculty of Intensive Care Medicine and the Royal College of Anaesthetists. Anaesthesia. 2020;75(6):785-799. doi:10.1111/anae.150549​)

For additional information on COVID-19:

Footnotes

References

  1. 1. Marini JJ, Gattinoni L. Management of COVID-19 Respiratory Distress. JAMA. 2020;323(22):2329-2330. doi:10.1001/jama.2020.6825
  2. 2. Papazian L, Aubron C, Brochard L, et al. Formal guidelines: management of acute respiratory distress syndrome. Ann Intensive Care. 2019;9(1):69. Published 2019 Jun 13. doi:10.1186/s13613-019-0540-9
  3. 3. Kluge, S., Janssens, U., Welte, T. et al. Empfehlungen zur intensivmedizinischen Therapie von Patienten mit COVID-19. Med Klin Intensivmed Notfmed (2020). https://doi.org/10.1007/s00063-020-00674-3).
  4. 4. Amato MB, Meade MO, Slutsky AS, et al. Driving pressure and survival in the acute respiratory distress syndrome. N Engl J Med. 2015;372(8):747-755. doi:10.1056/NEJMsa1410639
  5. 5. World Health Organisation: Clinical management of severe acute respiratory infection (SARI) when COVID-19 disease is suspected: Interim guidance V 1.2 (March 2020)
  6. 6. WHO guidelines: https://www.who.int/emergencies/diseases/novel-coronavirus-2019/technical-guidance
  7. 7. Sorbello M., Giacinto I. Di ,Bressan F. ,Cataldo R., Cortese G., Esposito C., Falcetta S., Merli G., Petrini F. . COVID-19 Airway Management Rev 1.1, SIAARTI, on behalf of SIAARTI Airway Management Research Group (March 2020)
  8. 8. Robba C, Battaglini D, Ball L, et al. Distinct phenotypes require distinct respiratory management strategies in severe COVID-19. Respir Physiol Neurobiol. 2020;279:103455. doi:10.1016/j.resp.2020.103455
  9. 9. Cook TM, El-Boghdadly K, McGuire B, McNarry AF, Patel A, Higgs A. Consensus guidelines for managing the airway in patients with COVID-19: Guidelines from the Difficult Airway Society, the Association of Anaesthetists the Intensive Care Society, the Faculty of Intensive Care Medicine and the Royal College of Anaesthetists. Anaesthesia. 2020;75(6):785-799. doi:10.1111/anae.15054

Management of COVID-19 Respiratory Distress.

Marini JJ, Gattinoni L. Management of COVID-19 Respiratory Distress. JAMA. 2020;323(22):2329-2330. doi:10.1001/jama.2020.6825

Formal guidelines: management of acute respiratory distress syndrome.

Papazian L, Aubron C, Brochard L, et al. Formal guidelines: management of acute respiratory distress syndrome. Ann Intensive Care. 2019;9(1):69. Published 2019 Jun 13. doi:10.1186/s13613-019-0540-9

Fifteen recommendations and a therapeutic algorithm regarding the management of acute respiratory distress syndrome (ARDS) at the early phase in adults are proposed. The Grade of Recommendation Assessment, Development and Evaluation (GRADE) methodology has been followed. Four recommendations (low tidal volume, plateau pressure limitation, no oscillatory ventilation, and prone position) had a high level of proof (GRADE 1 + or 1 -); four (high positive end-expiratory pressure [PEEP] in moderate and severe ARDS, muscle relaxants, recruitment maneuvers, and venovenous extracorporeal membrane oxygenation [ECMO]) a low level of proof (GRADE 2 + or 2 -); seven (surveillance, tidal volume for non ARDS mechanically ventilated patients, tidal volume limitation in the presence of low plateau pressure, PEEP > 5 cmH2O, high PEEP in the absence of deleterious effect, pressure mode allowing spontaneous ventilation after the acute phase, and nitric oxide) corresponded to a level of proof that did not allow use of the GRADE classification and were expert opinions. Lastly, for three aspects of ARDS management (driving pressure, early spontaneous ventilation, and extracorporeal carbon dioxide removal), the experts concluded that no sound recommendation was possible given current knowledge. The recommendations and the therapeutic algorithm were approved by the experts with strong agreement.

Empfehlungen zur intensivmedizinischen Therapie von Patienten mit COVID-19

Kluge, S., Janssens, U., Welte, T. et al. Empfehlungen zur intensivmedizinischen Therapie von Patienten mit COVID-19. Med Klin Intensivmed Notfmed (2020). https://doi.org/10.1007/s00063-020-00674-3).

Driving pressure and survival in the acute respiratory distress syndrome.

Amato MB, Meade MO, Slutsky AS, et al. Driving pressure and survival in the acute respiratory distress syndrome. N Engl J Med. 2015;372(8):747-755. doi:10.1056/NEJMsa1410639



BACKGROUND

Mechanical-ventilation strategies that use lower end-inspiratory (plateau) airway pressures, lower tidal volumes (VT), and higher positive end-expiratory pressures (PEEPs) can improve survival in patients with the acute respiratory distress syndrome (ARDS), but the relative importance of each of these components is uncertain. Because respiratory-system compliance (CRS) is strongly related to the volume of aerated remaining functional lung during disease (termed functional lung size), we hypothesized that driving pressure (ΔP=VT/CRS), in which VT is intrinsically normalized to functional lung size (instead of predicted lung size in healthy persons), would be an index more strongly associated with survival than VT or PEEP in patients who are not actively breathing.

METHODS

Using a statistical tool known as multilevel mediation analysis to analyze individual data from 3562 patients with ARDS enrolled in nine previously reported randomized trials, we examined ΔP as an independent variable associated with survival. In the mediation analysis, we estimated the isolated effects of changes in ΔP resulting from randomized ventilator settings while minimizing confounding due to the baseline severity of lung disease.

RESULTS

Among ventilation variables, ΔP was most strongly associated with survival. A 1-SD increment in ΔP (approximately 7 cm of water) was associated with increased mortality (relative risk, 1.41; 95% confidence interval [CI], 1.31 to 1.51; P<0.001), even in patients receiving "protective" plateau pressures and VT (relative risk, 1.36; 95% CI, 1.17 to 1.58; P<0.001). Individual changes in VT or PEEP after randomization were not independently associated with survival; they were associated only if they were among the changes that led to reductions in ΔP (mediation effects of ΔP, P=0.004 and P=0.001, respectively).

CONCLUSIONS

We found that ΔP was the ventilation variable that best stratified risk. Decreases in ΔP owing to changes in ventilator settings were strongly associated with increased survival. (Funded by Fundação de Amparo e Pesquisa do Estado de São Paulo and others.).

Clinical management of severe acute respiratory infection (SARI) when COVID-19 disease is suspected: Interim guidance

World Health Organisation: Clinical management of severe acute respiratory infection (SARI) when COVID-19 disease is suspected: Interim guidance V 1.2 (March 2020)

WHO Guidelines: Country & Technical Guidance - Coronavirus disease (COVID-19)

WHO guidelines: https://www.who.int/emergencies/diseases/novel-coronavirus-2019/technical-guidance

COVID-19 Airway Management

Sorbello M., Giacinto I. Di ,Bressan F. ,Cataldo R., Cortese G., Esposito C., Falcetta S., Merli G., Petrini F. . COVID-19 Airway Management Rev 1.1, SIAARTI, on behalf of SIAARTI Airway Management Research Group (March 2020)

Distinct phenotypes require distinct respiratory management strategies in severe COVID-19.

Robba C, Battaglini D, Ball L, et al. Distinct phenotypes require distinct respiratory management strategies in severe COVID-19. Respir Physiol Neurobiol. 2020;279:103455. doi:10.1016/j.resp.2020.103455

Coronavirus disease 2019 (COVID-19) can cause severe respiratory failure requiring mechanical ventilation. The abnormalities observed on chest computed tomography (CT) and the clinical presentation of COVID-19 patients are not always like those of typical acute respiratory distress syndrome (ARDS) and can change over time. This manuscript aimed to provide brief guidance for respiratory management of COVID-19 patients before, during, and after mechanical ventilation, based on the recent literature and on our direct experience with this population. We identify that chest CT patterns in COVID-19 may be divided into three main phenotypes: 1) multiple, focal, possibly overperfused ground-glass opacities; 2) inhomogeneously distributed atelectasis; and 3) a patchy, ARDS-like pattern. Each phenotype can benefit from different treatments and ventilator settings. Also, peripheral macro- and microemboli are common, and attention should be paid to the risk of pulmonary embolism. We suggest use of personalized mechanical ventilation strategies based on respiratory mechanics and chest CT patterns. Further research is warranted to confirm our hypothesis.

Consensus guidelines for managing the airway in patients with COVID-19: Guidelines from the Difficult Airway Society, the Association of Anaesthetists the Intensive Care Society, the Faculty of Intensive Care Medicine and the Royal College of Anaesthetists.

Cook TM, El-Boghdadly K, McGuire B, McNarry AF, Patel A, Higgs A. Consensus guidelines for managing the airway in patients with COVID-19: Guidelines from the Difficult Airway Society, the Association of Anaesthetists the Intensive Care Society, the Faculty of Intensive Care Medicine and the Royal College of Anaesthetists. Anaesthesia. 2020;75(6):785-799. doi:10.1111/anae.15054

Severe acute respiratory syndrome-corona virus-2, which causes coronavirus disease 2019 (COVID-19), is highly contagious. Airway management of patients with COVID-19 is high risk to staff and patients. We aimed to develop principles for airway management of patients with COVID-19 to encourage safe, accurate and swift performance. This consensus statement has been brought together at short notice to advise on airway management for patients with COVID-19, drawing on published literature and immediately available information from clinicians and experts. Recommendations on the prevention of contamination of healthcare workers, the choice of staff involved in airway management, the training required and the selection of equipment are discussed. The fundamental principles of airway management in these settings are described for: emergency tracheal intubation; predicted or unexpected difficult tracheal intubation; cardiac arrest; anaesthetic care; and tracheal extubation. We provide figures to support clinicians in safe airway management of patients with COVID-19. The advice in this document is designed to be adapted in line with local workplace policies.