3. TOPICS
Introduction
Icu unit preparedness
General measures
SARI
HFNO and NIPPV
Airway management
ARDS ventilation strategy
ECMO
Complications
Weaning and extubation
Disaster ventilatory strategies
4. INTRODUCTION
• Coronavirus disease 2019 (COVID-19) is a respiratory tract infection caused by a
newly emergent coronavirus,SARS-CoV-2, that was first recognized in Wuhan,
China, in December 2019.
• Approximately 14% develop severe disease requiring hospitalization and oxygen
support and 5% require admission to an intensive care unit
5. Severe cases,COVID-19 can be complicated by
• acute respiratory disease syndrome (ARDS),
• sepsis and septic shock,
• multiorgan failure, including acute kidney injury and cardiac injury .
This study also observed median duration of viral RNA detection was 20.0 days in
survivors, but SARS-CoV-2 virus was detectable until death in non-survivors.
• The longest observed duration of viral shedding in survivors was 37 days
6. • Early identification of those with severe illness, such as severe pneumoni/ARDS , allows for
optimized supportive care treatments and safe, rapid referral and admission.
• Patients who may present with mild symptoms but have high risk of deterioration
• Typical evolution of severe disease (based on analysis of multiple studies by Arnold Forest)
Dyspnea ~ 6 days post exposure.
Admission after ~8 days post exposure.
ICU admission/intubation after ~10 days post exposure.
However, this timing may be variable
Preparedness of an ICU Unit
Rapid response plan which include process for identifying and triaging the patient,
setting up infection control policies
most importantly protection of health care workers, procurement and maintaining inventory
of PPEs.
7. • To identify separate COVID ICUs, patients undergoing aerosol generating procedures
(HFNC, NIV, Intubation, Suctioning, Nebulisation) should preferably be kept in negative
isolation.
• All supportive care, ventilatory care, hemodynamic support etc. should be protocolised.
Oxygen supply and Ventilators
• In the event of mass respiratory failure, existing ICU beds are likely to be overwhelmed.
• Operation theatres, post-anaesthesia care unit beds, emergency department critical
care beds, and monitored beds in endoscopy suites & wards can be used to create
additional ICU beds.
• These areas have the advantage of having facilities for oxygen, suction and monitoring.
If ventilation has to be done in regular bed, to convert a single oxygen supply to dual, a
‘Y’ connector may be used at the outlet or an oxygen cylinder may be used.
8. Criteria for ICU admission
●Respiratory rate > 25 breaths per minute
● Confusion
● Hypotension requiring fluid resuscitation
● Hypothermia
● qSOFA >2
● PaO2 < 50 mm Hg on room air/SpO2 <90% on supplemental oxygen of 6 lpm
● Leukopenia
● Thrombocytopenia
● Uraemia
● Multi-lobar infiltrates
● Need for vasopressors
● Need for mechanical ventilation
Poor prognosis:-
Age
Lymphopenia
Raised nlr
Raised ldh
Raised d dimer
Raised ferritin
9. GENERAL MEASURES
● All patients should be assessed for vital signs including hypoxemia and shock.
● Oxygen supplementation should be done for hypoxemic patients with initial target
capillary oxygen saturation (SpO2) of >94%. (Mandatory)
● After initial stabilisation, oxygen supplementation should target an SpO2 of >90% in adults and
92% to 95% in pregnant adults. (Suggested)
• To looks for ARDS crtieria and in case when pao2 not available s/f ratio <315 to be
taken(including non-ventilated pts)
Rapid sequence intubation should be performed if difficult airway is not expected.
(Mandatory)
10. • Application of timely, effective and safe supportive therapies is the cornerstone
of therapy for patients that develop severe manifestations of COVID-19
• Management of severe COVID-19 is not different from management of most viral
pneumonia causing respiratory failure.
11. • The principal feature of patients with severe disease is the development of ARDS.
• Evidence-based treatment guidelines for ARDS should be followed, including
- conservative fluid strategies for patients without shock following initial resuscitation ,
- empirical early antibiotics for suspected bacterial co-infection until a specific diagnosis is
made,
- lung-protective ventilation,
- prone positioning,
- Extracorporeal membrane oxygenation for refractory hypoxemia.
CORTICOSTEROIDS
• Not indicated in treating SARS CoV2 as per available evidence
• Might prolong viral shedding
risk of secondary bacterial infections
• Use as per indicated in septic shock/if patient has other indications for steroid use
12. • Patients with SARI should be treated cautiously with intravenous fluids, because
aggressive fluid resuscitation may worsen oxygenation,especially in settings
where there is limited availability of mechanical ventilation
• Recognize severe hypoxemic respiratory failure when a patient with respiratory
distress is failing standard oxygen therapy and prepare to provide advanced
oxygen/ventilatory support.
• Hypoxemic respiratory failure in ARDS commonly results from intrapulmonary
ventilation-perfusion mismatch or shunt and usually requires mechanical
ventilation
• Patients may continue to have increased work of breathing or hypoxemia even
when oxygen is delivered via a face mask with reservoir bag (flow rates of 10–15
L/min, which is typically the minimum flow required to maintain bag inflation;FiO2
0.60–0.95).
13. HFNO AND NIPPV
• In set ups, where HFNC is not available then NIV, with preferably helmet as
interface should be tried (to prevent aerosolization).
• In ARDS, NIV has limited utility but Non-invasive ventilatory support may be tried
initially in selected patients under close observation in patients with mild to
moderate ARDS, who are hemodynamically stable, alert and able to handle
respiratory secretions or in scenarios when invasive ventilators are not available.
• Caution is advised when non-invasive ventilation or high flow nasal cannula are
being used, as there is risk of aerosol formation, especially in patients with poorly
fitting masks or interfaces.
14. • Adult HFNO systems can deliver 60 L/min of gas flow and FiO2 up to 1.0,peep of 2.7-7.4.
Paediatric circuits generally only handle up to 25 L/min, and many children will require an
adult circuit to deliver adequate flow.
• Compared with standard oxygen therapy, HFNO reduces the need for intubation.
• Patients with hypercapnia (exacerbation of obstructive lung disease, cardiogenic pulmonary
oedema), hemodynamic instability, multiorgan failure, or abnormal mental status should
generally not receive HFNO/NIV,
• although emerging data suggest that HFNO may be safe in patients with mild-moderate
and non-worsening hypercapnia,more comfortable to patient and reduced risk of imv.
15. • Patients receiving HFNO/NIV should be in a monitored setting and cared for by experienced
personnel capable of endotracheal intubation in case the patient acutely deteriorates or
does not improve after a short trial (about 1 hour).
• Evidence-based guidelines on HFNO do not exist, and reports on HFNO in other coronavirus-
infected patients are limited .
• NIV guidelines make no recommendation on use in hypoxemic respiratory failure (apart
from cardiogenic pulmonary oedema and post-operative respiratory failure) or pandemic
viral illness (referring to studies of SARS and pandemic influenza)
• Risks include delayed intubation, large tidal volumes, and injurious transpulmonary
pressures.
• Limited data suggest a high failure rate in patients with other viral infections such as MERS-
CoV who receive NIV .
16. AWAKE/SELF PRONING
• While on conservative oxygen therapy/niv/hfnc.
• Mild to moderate ards
• Patient cooperation
• Intact mentation
• Might avoid imv
• Might be usefull when imv not available
17.
18.
19.
20.
21. Recommendations for airway management in the COVID-19
patient group
• Negative pressure ventilation rooms with an antechamber are ideal
• Where this is not feasible, normal pressure rooms with closed doors are recommended.
• Positive pressure ventilation areas (common in operating theatres) must be avoided.
• Where an equivalent disposable item of equipment is available, this is always preferred
over reusable equipment
• The most important factor in choosing between these devices is prior familiarity.
• Oxygen can be administered via nasal cannulae, (standard or HFNO), simple facemask
or non-rebreather mask, with the general principle that the higher the flow rate, the
greater risk of virus aerosolization
• A viral filter MUST be inserted between the face mask and manual ventilation device
to minimise aerosolization.
The viral filter should be applied directly to the face mask as an increased number of
connections between the face mask and filter increase the opportunity for
disconnection on the patient side, with subsequent aerosolization of the virus.
22. • a pre-prepared ‘COVID-19 intubation tray’.
• Supraglottic Airways
Where a supraglottic airway is indicated, use of a second-generation device is
recommended as its higher seal pressure during positive pressure ventilation
decreases the risk of aerosolization of the virus.
- Closed suction systems
- Equipment outside the room
• Cardiac arrest trolley
• Airway trolley
• Bronchoscope
TEAM
• Limit numbers
• most experienced available staff.
• Consider excluding staff who are vulnerable to infection from the airway team.
• This includes staff who are older (> 60yrs), immunosuppressed, pregnant or have
serious co-morbidities.
• Allocate clearly defined roles
23. • ‘Buddy system’: all staff should ideally have donning and doffing of PPE individually
guided by a specially trained and designated staff member acting as a ‘Spotter’
before entering room
• A vice (V-E) grip(vortex approach) is recommended to maximize the facemask seal
and minimise gas leak after induction.
• Manual ventilation (which may cause aerosolization of the virus) should be
minimised unless required for rescue oxygenation.
24. • The extended duration of action of rocuronium potentially provides an advantage
in the COVID-19 patient group, by preventing coughing and potential aerosolization
of virus should attempts at airway management be prolonged.
• Pre-oxygenate with 100% FiO2 for 5 minutes, via a face mask with reservoir bag,
bag-valve mask, HFNO or NIV.
• Rapid sequence intubation is appropriate after an airway assessment that
identifies no signs of difficult intubation
• viral filter should be applied directly to the end of the tracheal tube.
• nasogastric tube should be placed at the time of intubation to avoid further close
contact with the airway
25. • Immediate ICU care after intubation
If using a humidified ventilator circuit, the viral filter used for intubation will need
to be removed in a timely fashion as it may soon become waterlogged.
In a dry circuit, a combined heat-moisture-exchanger (HME) and viral filter can be
left in place, but this means that nebulisers cannot be administered without
breaking the circuit (to place a nebuliser between the patient and the HME).
If the viral filter has been removed, the ventilator should be placed on standby for
all circuit disconnections (to minimise the risks of aerosolization). Great care should
be taken that ventilation is recommenced after the circuit is reconnected
26. • Implement mechanical ventilation using lower tidal volumes (4–8 mL/kg predicted
body weight, PBW)
• This is a strong recommendation from a clinical guideline for patients with ARDS, and is
suggested for patients with sepsis-induced respiratory failure who do not meet ARDS
criteria .
• The initial tidal volume is 6 mL/kg PBW; tidal volume up to 8 mL/kg PBW is allowed if
undesirable side-effects occur (e.g. dyssynchrony, pH < 7.15).
• Permissive hypercapnia is permitted.
• Plateau pressure goal: ≤ 30 cm H2O
• Check Pplat (0.5 second inspiratory pause), at least every 4h and after each change in
PEEP or VT.
• If Pplat > 30 cm H2O: decrease VT by 1ml/kg steps (minimum = 4 ml/kg).
• Consider use of incremental FiO2/PEEP combinations
27. • If patient does not show improvement in oxygenation, then proning should be
tried, preferably earlier.
• It is usually associated with significant improvement in oxygenation status.
• On an average 16-18 hrs of proning should be done.
• If there is a contraindication to proning, then recruitment manoeuvre can be tried
• Continous inflation technique
• Intermittent sigh
• Intermittent and proggressive peep
• Inverse ratio ventilation
• Proning
• Inhaled prstacyclins(iloprost,trepoprostenol)
• Aprv
• ecmo
28. RECRUITMENT MANEAOVERS
• Follow thorough aerosol precaution while proning and take utmost precaution to
avoid disconnection of ventilator circuit.
• The use of deep sedation may be required to control respiratory drive and achieve
tidal volume targets.
29. • In patients with moderate or severe ARDS, higher PEEP instead of lower PEEP is
suggested.
• PEEP titration requires consideration of benefits (reducing atelectrauma and
improving alveolar recruitment) vs risks (end-inspiratory overdistension leading to
lung injury and higher pulmonary vascular resistance.
• In younger children, maximal PEEP rates are 15 cmH20.
• Although high driving pressure (plateau pressure − PEEP) may more accurately
predict increased mortality in ARDS compared with high tidal volume or plateau
pressure .
• Data from RCTs of ventilation strategies that target driving pressure are not
currently available.
30. • Higher PEEP and RMs were both conditionally recommended in a clinical practice
guideline.
• However, a subsequent RCT of high PEEP and prolonged high-pressure RMs showed
harm.
• Monitoring of patients to identify those who respond to the initial application of
higher PEEP or a different RM protocol, and stopping these interventions in non-
responders, is suggested .
• In patients with moderate-severe ARDS (PaO2/FiO2 < 150), neuromuscular
blockade by continuous infusion should not be routinely used.
31. • Avoid disconnecting the patient from the ventilator, which
results in loss of PEEP and atelectasis.
• Use in-line catheters for airway suctioning and clamp
endotracheal tube when disconnection is required (for
example, transfer to a transport ventilator).
32. • In settings with access to expertise in ECMO, consider referral of patients with refractory
hypoxemia despite lung protective ventilation.
• An RCT of ECMO for adult patients with ARDS was stopped early and found no statistically
significant difference in the primary outcome of 60-day mortality between ECMO and
standard medical management (including prone positioning and neuromuscular blockade).
• However, ECMO was associated with a reduced risk of the composite outcome of mortality
and crossover to ECMO.
• In patients with MERS-CoV infection, ECMO vs conventional treatment was associated with
reduced mortality in a cohort study.
• ECMO should only be offered in expert centres with a sufficient case volume to maintain
expertise and that can apply the IPC measures required for adult and paediatric COVID-19
patients
33.
34.
35. • In The Lancet, Fei Zhou and colleagues ,provide insight into the clinical course and
mortality risk for adults with COVID-19 severe enough to require hospitalisation.
• They report findings from 191 patients with COVID-19 from Wuhan during the first
month of the outbreak, and follow them through to discharge (n=137) or death
(n=54).
• In-hospital mortality was high (28%), much higher than in other reports that had
incomplete follow-up data and was very high among the 32 patients requiring
invasive mechanical ventilation, of whom 31 (97%) died.
• This might reflect a higher proportion of patients admitted with severe disease in
the early stages of the outbreak.
In another report from Wuhan, mortality was 62% among critically ill patients
with COVID-19 and 81% among those requiring mechanical ventilation.
36.
37.
38. • Patients should ideally be non-infective prior to extubation but this is likely to be
unfeasible as resources are drained.
• In situations where a patient is still at risk of viral transmission, the following
recommendations should be observed:
1. Patients should ideally be ready for extubation onto facemask.
2. NIV and HFNO should be avoided where possible.
3. Two staff members should perform extubation.
4. The same level of PPE should be worn for extubation as is worn by the Airway
Operator, Airway Assistant and Team Leader during intubation.
5. The patient should not be encouraged to cough.
6. A simple oxygen mask should be placed on the patient immediately post extubation
to minimise aerosolization from coughing.
7. Oral suctioning may be performed, with care taken not to precipitate coughing
39. DISASTER VENTILATROY STRATEGIES
• SPLITTING VENTILATOR:
Pressure-cycled ventilation should be used, with a driving pressure <13-
15 cm
40. • OUTPATIENT DESIGNED BPAP MACHINE FOR INTUBATED :-
Less ill patients,patient’breath triggered,limited fio2,light sedation might be used
• OXYLATOR RESUSCITATOR:-
• Small automated device which can provide pressure-cycled ventilation.
• Relatively inexpensive and there still seems to be a reasonable supply available.
• Allows for delivering titratable levels of PEEP.
• VOTRAN AUTOMATIC RESUSCITATOR
• PEEP is fixed at a relatively low level, around ~5-8 cm)
41. To summarize...
• Early identification of SARI
• fully prepared ICU plan with PPEs for HCW
• Timely, effective and supportive therapies
• ARDS guidelines to be followed
• HFNO preferred over NIPPV
• Avoidance and protection from aerosolising procedures
• Avoid delaying IMV
• To prevent ventilator associated complications
• Carefull extubation
• Disaster ventilatory strategies e.g. Split vent could be used.
