The Power to Choose: NIV as an Alternative to Intubation

Reference Links

Google search “how to Optimize NIPPV”

Google search “Predicting Failure of NIPPV” & “Challenges of noninvasive ventilation”

https://www.sciencedirect.com/science/article/pii/S2341287919301620

https://doi.org/10.1016/j.anpede.2019.01.015

https://doi.org/10.1183/09031936.05.00085304

https://doi.org/10.1177/08850666241268452

https://pubmed.ncbi.nlm.nih.gov/39654395/

http://dx.doi.org/10.20515/otd.1498328

https://doi.org/10.1164/rccm.201610-2138ED

DOI: https://doi.org/10.4187/respcare.06635

https://rc.rcjournal.com/content/64/6/617

https://publications.ersnet.org/content/errev/27/149/180029

https://rc.rcjournal.com/content/58/8/1367

https://pmc.ncbi.nlm.nih.gov/articles/PMC5111281/

https://www.emjreviews.com/wp-content/uploads/2018/11/Noninvasive-Ventilation....pdf

https://www.emjreviews.com/wp-content/uploads/2018/11/Noninvasive-Ventilation....pdf

https://www.researchgate.net/profile/Dhruva-Chaudhry/publication/276211028_Non-Invasive_Ventilation_Challenges_in_Usage_and_Applications/links/649d68f5c41fb852dd3e5937/Non-Invasive-Ventilation-Challenges-in-Usage-and-Applications.pdf

https://www.nationaljewish.org/conditions/als/treatment/niv

https://www.atsjournals.org/doi/10.1164/rccm.201606-1306oc

https://bmcanesthesiol.biomedcentral.com/articles/10.1186/s12871-017-0409-0

https://publications.ersnet.org/content/breathe/10/3/230#:~:text=Patient%20selection%2C%20underlying%20pathology%2C%20the,failure%20%5B8%E2%80%9310%5D.

https://publications.ersnet.org/content/breathe/10/3/230.full.pdf

Lecture Planning

2007 was when I first had the ability to effectively deliver PPV (CPAP) in the prehospital setting.

2010 - Started in CCT w/ Oxylog 3000 w/ basic NIPPV

2013 - LTV1200, a little more sophisticated

2016 - ReVel even better, but with weak blower (Blower Demand)

2023 - Hamiltion T1 (GAME CHANGER) We finally had a full fledge ICU ventilator in a transport package

Yet we still see so many patients intubated for respiratory failure based

1. The ability to monitor waveforms with the T1 had transformed the way we manage respiratory distress patients outside the hospital.

   1. Now we can monitor for dynamic hyperinflation and do something about it.

2. Managing a patient with hypercapnica encephalopathy requires a careful approach from a skilled clinician

   1. Careful monitoring of mental status and ability to protect airway

      1. In transport, if we’re not task saturated, we should be able to closely monitor our patients with 1:2 ratio. There MAY be a wider safety margin to manage patients with worse encephalopathy as long as providers are prepared to immediately clear airway

   2. Success depends more on the underlying cause of the hypercapnea rather than the severity of comatose.

      1. COPD typically responds well to NIV, so AMS from COPD would be an appropriate use

3. Pulmonary Edema

   1. CPAP / PEEP

      1. Recruits alveoli, decreases RV preload, Decreases LV Afterload

      2. Reduces needs for intubaiton

      3. decreases mortality

      4. CPAP or BiPAP depends on patient presentation

         1. CPAP to increase oxygenation, recruite alveoli, and displace fluid

4. Immunocompromised patients

   1. Biggest concern with these patients is their risk of infection associated with intubation.

      1. Every effort should be taken to avoid intubation.

   2. HFNC has shown better outcomes than NIV

      1. Possibly due to better tollerance and less VALI (Barrotrauma)

5. AHRF

   1. Pneumonia

      1. Requires PEEP to correct shunt.

      2. NIV shows reduced intubation rates

      3. If NIV used to RESCUE patients in EXTREME Distress, mortality is higher.

         1. This just continues to reinforce the principle that NIV must be started early to have mortality benefits. Otherwise, mortality is worse.

      4. Patients should have prolonged CPAP to keep alveoli open while antibiotics start to work, otherwise derecruitment occures and patients desaturate.

   2. ARDS

      1. High rate of NIV failure

         1. Some studies suggest P:F <150, immediate IMV is better

         2. Some studies suggest a trial of NIV is appropriate and reassess at 1 hour

            1. If P:F still <200, then that is a marker of severe illness and a trigger to intubate.

      2. NIV in ARDS patients often results in…

         1. Higher VTs

         2. Lower PEEP

            1. Possibly due to limitations achieving higher PEEP

               1. Ventilator limits

               2. Inducing mask leak

      3. Just like in IMV, we must target lower Tidal Volumes and avoid VILI

         1. High tidal volumes at 1 hours of NIV = indepentently associated with higher 90 day mortality

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Respiratory-rate Oxygenation (ROX) Index

Just about every study suggests that:

1. Intubation lead to higher mortality

2. NIPPV leads to lower mortality

3. NIPPV is most effective when used with patients who have pathologies that are likely to improve rapidly such as Exacerbated COPD and ACPE

4. When a patients does not turn around quickly, they have higher mortalities when intubation is delayed

This makes for a difficult decision.

1. What patients should have a trial of NIPPV?

2. How can you determine the patient is failing NIPPV and needs to be intubated?

3. How long should you wait before making that decision?

Factors that effect NIPPV failure

• Inappropriate patient selection

• Severity of underlying pathology

• Patient-ventilator asynchrony

• Severe AHRF (ARDS)

  • P:F <150 does not do well

• Interface Intolerance (Poor mask fit)

  • Discomfort

  • Large Leak

• Amount of experience of the clinician with NIV / Clinician’s comfort level

• ** Task saturation include staffing limitations

PPV and Heart-Lung Interaction

• Zones of West

  • 1 - ventilation w/o perfusion (Deadspace Ventilation)

    • Healthy lung has almost zero Zone 1

  • 2

  • 3

• Goal should be to optimize PEEP

  • Hypoxic pulmonary vasoconstriction is lowest at optimal FRC

    • Less than optimal FRC and pulmonary vascular constricts increasing RV afterload.

    • Excessive PPV hyperinflates alveoli leading to microvascular compression and also induced pulmonary hypertension

      • This induces more deadspace ventilation

      • Increases RV workload

• Increased intrathorasic pressure from PPV

  • Increased RAP is “reflected in an increased right atrial Pressure” (aka CVP)

    • This can give a false sense of adequate volume status

      • Although, I think we know now that CVP is a bad measurement for volume status

    • This reduces RV Preload, and thus LV Preload, reducing CO

    • Elevated RV pressures w/ decreased LV filling can cause the septal wall to bow inward further decreasing LV filling

      • This can be corrected with IV fluid

** NOTE: “but strict negative fluid balance may be harmful to [hemodynamically unstable patients] because West Zone 3 becomes West Zone 2, which makes alveolar perfusion dependent on alveolar pressure, increasing the ventilatio-perfusion mismatch further” (Dilken, O., Erdogan, E., and Dikmen, Y. November 2018. Noninvasive ventilation: Challenges and pitfalls. European Medical Journal)

PPV and COPD

PPV and Hypercapnic Encephalopathy

• Lower SpO2’s allow more CO2 to bind to hemoglobin in venous blood for transport to the lungs for exhalation. This is called the Haldane effect. As a result, when trying to manage a patient with severe hypercapnea (including those with hypercapnic encephalopathy) it’s better to keep SaO2 lower (88-92%) to allow more CO2 to be eliminated.

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References:

1. Noninvasive Ventilation: Challenges and Pitfalls, Olcay Dilken, Elif Erdogan, Yalim Dikmen, European Medical Journal, November 2018, https://www.emjreviews.com/wp-content/uploads/2018/11/Noninvasive-Ventilation....pdf

   
   
   Success of Failure of NIV

Patient Selection, underlying pathology, the severity of ARF, expertise of NIV, and interface intolerance (air leaks, discomfort, etc.

Starting to aggressively