pulmonary edema, RSI, and cardiac reserve...

[krebse]

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Have any of you experienced a cardiac arrest immediately post RSIing a pt for pulmonary edema? We had a pt that wouldn't tolerate bipap. I wanted to intubate him, but my attending said no because frequently these pts have so little cardiac reserve that after you paralyze/sedate them they arrest. We aggressively nitroed him and coaxed him into the bipap after a while. He turned around and was looking like a rose on his bipap when I saw him getting wheeled out of the ED. Anyhow, I'd like to read more about this phenomenon my attending was talking about, but I'm not sure the best way to find that info. My tiny tintinalli doesn't mention it. thoughts? stories? thanks!

Liz

 

[Arcan57]

I've seen hypotensive and/or underresuscitated patients code after RSI. However, I've also seen patients on multiple pressors that we were able to start weaning the pressors off after taking away the work of breathing. It doesn't sound like your patient was at a significant risk for coding after RSI(based on a BP that allowed aggressive nitro). However, the hypertensive CHF patient with pulmonary edema can usually be turned around quickly with lots of nitro and a little lasix. So unless their mental status is off or they won't tolerate the mask then there's no reason to intubate them.

 

[BADMD]

...reserve that after you paralyze/sedate them they arrest...

I'm not sure what this really means, physiologically.

In theory, someone in severe CHF has high pulmonary vein pressures, a condition that should be responsive to positive pressure ventilation.

RSI/Sedation will knock back some of the central response to being in extremous. If you have a patient who is completely dependent on excess catecholamines for cardiac output, then blunting catechol triggering and blunting the catechol response could result in them crumping on you. That is going to be a fine line as the same issue can result in them crumping on you when they exceed their limits if you decide not to intubate them and try to stabilize with NIPPV.

This is going to be part of the art. Your attending saw something that said "I can turn this one around." Ultimately, if you can avoid intubation, it is likely better. That being said, not intubating can be a disaster. Hence, the art...

 

[a_ditchdoc]

From a physiological standpoint, RSI should help your pulmonary edema patients, especially with generous helping of PEEP. The problem comes while you are attempting to RSI a CHF patient that has poor oxygen reserves.

Often these patients already cannot be hyperoxygenated with a nonrebreather or BVM, hence the reason for intubation. Starting with a saturation that is barely 90% is bad enough. Unfortunately, the first instinct after administration of paralytics or sedatives is to place the patient supine. I have seen this go horribly wrong on a few occasions. The secretions from the airways start pouring from the mouth making intubation difficult. The apex of the lungs, where most of the ventilation was probably occurring, fills with foamy fluid. You can no longer effectively ventilate these patients. Even if you get the intubation in record time, the oxygen saturation will continue to fall for a few minutes even if you sit them back upright to allow ventilation of the apices of the lungs (unlike COPD'ers that rebound pretty quickly most of the time). If they arrest, you might as well start cancelling christmas plans for them. I don't think I recall ever having seen one come back followng an arrest in these circumstances. You cannot do effective CPR with the patient sitting upright, and you cannot ventilate with the patient lying flat.

BiPap is a wonderful thing. It has greatly reduced the need for intubation. The problem is, what to do when it doesn't work? If you wait too long, you're in a corner, intubate too early and you probably could have turned most of them around. Nasal intubation should be a consideration. It can be done while the patient is sitting upright and is a relatively straight forward procedure in many cases. It does seem to be hit or miss in reference to success rates (my success rates anyway). I try to use a smaller tube size. A horrible nosebleed in a crashing pulmonary edema patient is the stuff horror movies are made of.

I have come to prefer intubating CHF patients with them in a semi-reclining position as it maintains some ability to ventilate them. I think this is the best option if RSI is necessary. Resist the urge, or others urges, to place the patient flat. I really think this is what seals many of these patients fate, rather than some underlying cardiac decompensation.

 

[jethro136]

Unfortunately, if a CHF patient doesn't respond to medical therapy, the prognosis isn't great for them no matter how you intubate and set the vent. NIPPV hasn't changed the in-hospital mortality for acute pulmonary edema. Many of the patients who "improve" in the ED with NIPPV will still go on to decompensate in the MICU.

Part of the problem with patients crumping after you intubate them during a CHF exacerbation is that lying them flat increases the filling pressures even more than they already are. There's a reason they have orthopnea and tripod when they're about to die. They decompensate, from a Frank-Starling point of view, when you lie them flat because they're already way beyond the good part of the curve.

 

[krebse]

thanks guys, the oxygen reserve and laying supine makes total sense and is probably what he was referring to. I extrapolated cardaic reserve, but I think your explanations make more sense. I think I'm going to do a case presentation on this pt and give a bread and butter synopsis of acute pulmonary edema/CHF management. If anyone has and recommendations of particular things to read in prep for a presentation I'd appreciate the guidance! thanks

Liz

 

[roja]

The other think to keep in mind, is often attendings or subject to the 'last case' ism. Meaning, maybe your attending, or someone in his/her group, had a patient code after RSI who was a 'CHF' patient.

It is natural to try and make direct links, and sometimes you can. However, perhaps a patient who has a poor EF, has an MI and goes into APE. Needs to be intubated and then codes. It is possible they would have coded anyway, and it just happened coincidentally. Or maybe they had an atypical presentation of a PE. Or something else.

We use many different methods to come to decisions. I have attached an article that htalks about the pros and cons. If you understand them all, you can better improve your abilities.


So, I am not sure what your attending was talking about. I think most people would say aggressive nitro drip (I tend to start at 150mcg for severe APE), lasix plus or minus (depends on who you talk to... somewhat academically controversial) and sublingual captopril.

Most important point in APE I learned? The hardest thing to learn in residency is to NOT intubate. APE patients are perfect examples. They come in looking terrible. Junior residents alwasy want to intubate. 🙂

 

[docB]

I think it's important to make the distinction between decompensation due to the RSI vs. the positive pressure ventilation. I really have not seen many people decompensate due to RSI. Any one who is hypotensive, especially those who are dry and/or preload dependent can decompensate with the positive pressure.

I frequently tell my medical and paramedic students that putting someone on positive pressure ventilation and putting them on a heart/lung machine are two of the most fundamental changes medicine can inflict on someone's normal physiology. It's crucial for anyone who will be managing airways and respirations to understand exactly why positive pressure ventilation makes hypotension worse, can cause a tension pneumo and can influence ICP.

 

[deleted65604]

I had a great check-out a few months back, "Just intubate this lung transplant patient with pneumonia who is getting helicoptered out soon, the accepting doctor wanted her stable for transport" She was satting in the low 90's on a non-rebreather, not in respiratory distress. OK, so I intubated her. She wasn't satting well, so we increased the PEEP and her pressure literally dropped to zero (still had a pulse). She had 2 little tiny IV's in, so I did a subclavian, and dropped her lung, giving her a tension pneumo. With a chest tube, a femoral line and some fluid and pressors, we got her stabilized and shipped out. (Sigh) She survived, only to die a couple of months later after she opted for comfort care only.

Moral of the story, an immunosuppressed lung transplant patient, with resultant wicked pulmonary hypertension, is likely on the verge of sepsis and is going to tank her pressure with sedatives and PEEP. The perfect storm for hypotension.

 

[txterp98]

krebse, do you have a subscription to Emergency Medicine Practice? (www.ebmedicine.net)

If so, review these two issues:

1) August 2008: Ventilator Management: Maximizing Outcomes In Caring For Asthma, COPD, And Pulmonary Edema

2) December 2006: Acutely Decompensated Heart Failure: Diagnostic and Therapeutic Strategies

They should get you on your way for a presentation.

 

[krebse]

thanks txter, this looks like exactly what I need. BTW, other residents, we get free access to the stuff he mentioned through EMRA.

Liz

 

[Jeff698]

I had a great check-out a few months back, "Just intubate this lung transplant patient with pneumonia who is getting helicoptered out soon, the accepting doctor wanted her stable for transport"

Someone actually checked that patient out to you before intubation?! Did I misunderstand?

Turning over procedures (other than minor lacs or I&Ds) is on my "never turn over" list and, IMHO, just plain bad form.

Take care,
Jeff

 

[Hamhock]

thanks txter, this looks like exactly what I need. BTW, other residents, we get free access to the stuff he mentioned through EMRA.

Liz

How do we get access through EMRA?
HH

 

[Jeff698]

How do we get access through EMRA?
HH

http://www.emra.org/emra_benefits.aspx?id=29796

They made a good decision when they started giving EMRA members free access. I've been paying to drink the KoolAid since being a resident.

It seems they should pay me a kickback for as often as I recommend their stuff. Sadly, it doesn't happen that way. 🙂

Take care,
Jeff

 

[deleted65604]

Someone actually checked that patient out to you before intubation?! Did I misunderstand?

Turning over procedures (other than minor lacs or I&Ds) is on my "never turn over" list and, IMHO, just plain bad form.

Take care,
Jeff

Yes, it was checked out to me. The other doc had a meeting with our boss right after work.

I found this little blurp on mdconsult out of Piccini & Nilsson: The Osler Medical Handbook, 2nd ed.

Maintaining euvolemia and hemodynamic stability (in pulmonary hypertension) can be difficult because of the interplay between preload dependence and interventricular interdependence. Care should be taken to avoid overdiuresis and agents that can lower systemic arterial pressure.

Consider that most COPD patients as a result of their disease, have some degree of pulmonary hypertension, intubation is going really decrease preload and might cause the patient to crump.

In a heart failure patient, this decrease in preload is therapeutic, but not in patients with chronic lung disease.