Episode #4 - Pulmonary Edema

[Tony Held]

Pulmonary Edema - Episode #4

There's nothing quite like the struggle of keeping a pulmonary edema patient alive.  Win, and you have a patient requesting discharge from the ER.  Lose, and there's nearly no hope of coming back.  Listen up, treat fast and accurate, leave the ER wondering why you brought this patient in the first place.




Podcast Notes are here


Sources:

The Lost Art of Mask Bagging – Part 1
Raymond Che
CBCEMP Podcast. August 18, 2017

Hydrostatic versus increased permeability pulmonary edema: diagnosis based on radiographic criteria in critically ill patients.
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Many Benefits of CPAP
Marvin Wayne
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State of the Evidence: Mechanical Ventilation with PEEP in Patients with Cardiogenic Shock.
Wiesen, Jonathan et al.
Heart (British Cardiac Society) 99.24 (2013): 1812–1817.

A Comparison of Continuous and Bi-Level Positive Airway Pressure Non-Invasive Ventilation in Patients with Acute Cardiogenic Pulmonary Oedema: A Meta-Analysis.
Ho, Kwok M, and Karen Wong.
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EMCrit Podcast 1 – Sympathetic Crashing Acute Pulmonary Edema (SCAPE).
Scott Weingart.
EMCrit Blog. Published on April 25, 2009.

Sympathetic Crashing Acute Pulmonary Edema.
Agrawal, Naman et al.
Indian Journal of Critical Care Medicine 20.12 (2016): 719–723.

Critical Care Transport, 1st Ed.
America Academy of Orthopaedic Surgeons, UMBC, American College of Emergency Physicians
Jones & Bartlett Learning

Effects of an inhaled β2-agonist on cardiovascular function and sympathetic activity in healthy subjects.
Snyder EM, Wong EC, Foxx-Lupo WT, Wheatley CM, Cassuto NA, Patanwala AE.
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Effects of prehospital medications on mortality and length of stay in congestive heart failure.
Wuerz RC, Meador SA.
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Bronchodilator therapy in acute decompensated heart failure patients without a history of chronic obstructive pulmonary disease.
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Prehospital Nitroglycerin Safety in Inferior ST Elevation Myocardial Infarction.
Robichaud L, Ross D, Proulx MH, Légaré S, Vacon C, Xue X, Segal E.
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[Kris Thompson]

Good post!

The Robichaud data isn't huge, but I agree that nitroglycerin is as safe in RV STEMI as it is in anterior STEMI. There's some other supportive evidence out there, but it is just a few patients. On the other hand, there's no good data that shows increased risk of hypotension in RVI. Rapid titration of nitroglycerin (up to very high doses) via IV infusion is probably the safest way to go for all patients, whether they have SCAPE, exacerbation of CHF, or ACS.

I will just mention that you need to be very careful with the benzos in these patients. If they are really sick, some versed might just take away their will to live and you might be put into a bad spot in which you have to intubate them. Benzos are fine, and will help the right patient, but are not without risk. Dose low and slow!

What do you think about treating HR and BP in SCAPE with calcium channel blockers (or maybe beta blockers) if a touch of versed and a lot of nitro doesn't help?

[Tony Held]

Kris Thompson said:

I will just mention that you need to be very careful with the benzos in these patients. If they are really sick, some versed might just take away their will to live and you might be put into a bad spot in which you have to intubate them. Benzos are fine, and will help the right patient, but are not without risk. Dose low and slow!

Rarg! Busted. Yes I was not very clear on that in the podcast. I do mean quite literally "maintain their newfound zen". Don't overdo it. Get them to a happy place and keep them RIGHT there. These patients are tired, and benzos are prescribed as sleep aids. They certainly come with that complication. Thanks for keeping me honest, Kris.

Kris Thompson said:

What do you think about treating HR and BP in SCAPE with calcium channel blockers (or maybe beta blockers) if a touch of versed and a lot of nitro doesn't help?

I really hadn't thought about it until you brought it up.

So calcium channel blockers have really interesting implications, especially since nifedipine is being used as a treatment or even pretreatment for high-altitude pulmonary edema. Counterintuitively, calcium channel blockers seem to be the bastard stepchild in the literature of pulmonary edema. There are far more case reports published about calcium channel blocker overdoses causing pulmonary edema, but I'm not sure I understand the mechanism, nor is that the patient we're dealing with. Diltiazem is also discussed in the treatment of pulmonary hypertension, though most articles I found suggest nifedipine is a bit more selective for the pulmonary vasculature.

I worry about tweaking the heart too soon, but that said, I just don't have enough experience with those medications in hypertension.

But if we're diving into therapies I have no experience with, I'm curious about using inhaled Flolan (epoprostenol). It's quick on, quick off. And while the weaning phase is well documented, I wonder if it would be necessary in the SCAPE patient. So instead of those in-line bronchodilators potentially causing increased pulmonary pressure, use an in-line pulmonary vasodilator to decrease the pressure.

SPOILER: Click to show

{Click for Sources}
Calcium channel blockers in congestive heart failure: theoretic considerations and clinical experience.
Colucci WS, Fifer MA, Lorell BH, Wynne J.
Am J Med. 1985 Feb 22;78(2B):9-17.

Nifedipine induced pulmonary edema
Anaesthesia, Pain & Intensive Care
www.apicareonline.com/nifedipine-induced-pulmonary-edema/

Inhaled epoprostenol for the treatment of pulmonary arterial hypertension in critically ill adults.
Buckley MS, Feldman JP.
Pharmacotherapy. 2010 Jul;30(7):728-40.

[silvia]

Good podcast! Since we are talking about using CPAP and BIPAP as a way to get folks through this pulmonary edema crisis, remember everybody to consider the risks of the (not-always-as-benign-as-it-looks) facemask version of positive pressure ventilation (NIPPV).
For masks that cover both mouth and nose, if that tubing comes apart inadvertently (or if a confused patient pulls it off) the patient will quickly asphyxiate if they are not strong enough to pull off the mask. Patients have died this way, yikes! In the ICUs they have a rule that only patients that are awake enough and strong enough are allowed to try full face mask NIPPV.
Also, it is common for them to swallow quite a bit of air, so even in the best scenario they can get a bloated stomach, and some of those folks then puke. Imagine if you will throwing up into a tight sealed face mask as a machine shoves the vomit right down into your lungs. Now you have a very complicated airway crisis!

Bottom line is never leave a NIPPV patient alone, and always realize some patients tolerate it well, others will have a sudden need to be intubated, so be ready with airway plan B!

[Tony Held]

silvia said:

Bottom line is never leave a NIPPV patient alone, and always realize some patients tolerate it well, others will have a sudden need to be intubated, so be ready with airway plan B!

Yes absolutely. I'm frequently questioned about putting these masks on patients whose mental status would not typically support NIPPV. "Don't you think that's against protocol putting CPAP on a patient with GCS < 15?" My argument here is that I am bedside 100% of their care and monitoring them from two feet away at all times. Hypoxia is a reversible cause of confusion, and I expect their course to improve rapidly during treatment.

The practice standard of patients needing to self-rescue from a NIPPV failure applies when practitioners need to walk away from the patient. These patients within the hospital are NOT monitored one-on-one unless they are being acutely managed. An ICU using non-invasive ventilation as a longer term strategy than the acute management of a disease needs patient cooperation.