Clinical Question

Specialties CRNA

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I had my first case of negative pressure pulmonary edema yesterday. 26 YO for a knee scope, declined SAB and LE block, she requested a general and due to her GERD/heartburn, I chose GA with ETT. I did a RSI without difficulty and the case proceded without incident. During emergance, she seemed to have a bit of difficulty coordinating her breathing, and had a couple of MINOR episodes of desaturation as I woke her up. Eventually, I extubated her when reflexive but due to her continued coughing she never truely followed commands. Her sat was 98% with evidence of good exchange occuring immediatly. Upon arrival in PACU, her sats were 89% and we placed her on a simple mask at 10 liters with sats improving to 93-95%. She had fairly severe crackles throuout and 10 mg of lasix improved things immediatly. A CXR showed a PE picture and improved over the next couple of hours. When thinking about her ETT, there was a fair amount of frothy pink sputum present. Should have sent alarm bells off sooner I guess. She was discharged home a number of hours later, happy and feeling fine. I'm looking for possible explainations. Anyone care to comment?

deepz... my point regarding the literature is as follows: if it is a common event that patients develop NNPE while intubated (as experienced by you and Keermie) then surely it should be in textbooks, or at least in case reports... but it isn't. and every clinical observation that can further our field, help others in similar situations, SHOULD be written up.

so back to my original points

1) Original poster's patient didn't have NNPE

2) correct management is PEEP and not diuretics

3) it can only happen with a closed glottis, not with an ETT (no matter how hard somebody bites on it)

I know however, that many instructors (even MDAs) perpetuate this myth - and it just isn't true...

Well I have to admit, the MDA running the recovery room informed me of her diagnosis after seeing a chest X-ray and she ordered the lasix. I'm not sure that applying CPAP in this instance whould have been as effective as the lasix which worked in minutes. (Yes I know obout the vasodilatory properties but whatever the MOA, it worked rapidly and completly).

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I did attempt to look it up, and was surprised to find limited literature on the subject. What a great thesis project!

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I did attempt to look it up, and was surprised to find limited literature on the subject. What a great thesis project!

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Agree with Trauma Tom, just don't want to see this turned into a who is better than who debate than the actual topic. Haven't seen NPPE myself but also have studied it to be treated with Positive Pressure ventilation and not a diuretic.

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So in an awake, alert, young woman with a touch of anxiety because she is coughing and is aware something is not quite right you all would strap a CPAP mask on her for a couple of hours rather that administer 10 mg of lasix? Assuming it was NPPE and if not, what is an alternative diagnosis?

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wintermute... 9 times out of 10 versed/ativan works great!!! (not to mention that benzos provide some vasodilation as well) as well as a good O2 mask.... if you are truly concerned about NPPE you'd be surprised how glad they are with a CPAP mask (and again, with a touch of versed... :)...

something i recommend to everybody going into this field: get together with a respiratory therapist, and have them strap on CPAP or BIPAP masks and feel it for yourself... another good thing to do is to connect yourself to a vent and try different ventilation modes, just remember to relax enough so that you aren't fighting the vent

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ok

and I challenge you to find in the anesthesia literature (don't use the medical ICU literature though - cause they have no clue) ANY case reports of negative pressure pulmonary edema in the setting of an intubated patient...

Pulmonary Edema-Possible Prevention, Cause

To the Editor

This is in response to the Letters to the Editor on the subject of postoperative pulmonary edema. In our institution, we have observed and recorded episodes of pulmonary edema in young, strong, healthy patients after suffering airway obstruction following extubation since we started our quality improvement program several years ago. We have assumed for quite some time that the diagnosis was negative pressure pulmonary edema.

We agree with Dr. O'Hara when she states, 'This happens more in July, when new residents learn how to evaluate awakening and readiness for extubation, but these incidents happen to experienced anesthesiologists as well.' For several years in our teaching institution, the incidence was around one in 2,000 extubations. In 1988 we contacted an endotracheal tube manufacturer to build a modified endotracheal tube specifically designed to have the capability to deliver topical anesthesia to the upper airway to eliminate or diminish bucking and coughing during emergence from general anesthesia. In subsequent studies which we undertook, we were able to determine that this was the case.'

For the last two years we have been using topical lidocaine prior to emergence and allowed the patients to wake up with the endotracheal tube in place. By doing so we were able to eliminate or greatly minimize bucking, coughing and also (as a by-product) laryngospasm and/or any other form of upper airway obstruction that may result in pulmonary edema. Negative pressure pulmonary edema following laryngospasm was decreased to one in 10,000.

Another by-product has been the decrease and/or elimination of post intubation sore throat, since most of the trauma to the airway is due to bucking and coughing during emergence, especially if the intubation has been smooth and easy.

Marc G. Viguera, M.D.

Head, Department of Anesthesiology The Buffalo General Hospital Buffalo, NY.

http://gasnet.med.yale.edu/societies/apsf/loadurl/loadurl.php?www.gasnet.org/societies/apsf/newsletter/1994/spring/

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Having had a few experiences with this matter, I wanted to add some input. I have just finished my 3 year program and done over 1200 cases. I have seen a mild NPPE, on a young healthy strong patient, during a MAC case for a cystoscopy. The propofol drip was run at a higher rate and the airway not supported adequately. The patient was forced to pull against a semi-closed glottis for most of the case and the NPPE developed just at the end of the case. I have also seen it develop from patients biting the tube during emergence when still in stage two.

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Diprivan, the letter you have provided seems to imply that the NPPE was happening AFTER extubation, rather than in patients biting down with the tube in place.

"we have observed and recorded episodes of pulmonary edema in young, strong, healthy patients after suffering airway obstruction following extubation"

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On awakening after orthopaedic surgery, a healthy 34 y/o male patient is suspected of biting his endotracheal tube for 5-10 seconds. Bloody froth is observed within seconds of the apparent bite. Pulmonary edema sets in.

Question #1: Can a 5-10 second bite on an 8.0 endotracheal tube trigger NPPE?

Question #2: Is the immediate appearance of a bloody froth consistent (or possible) with NPPE given the supposed obstruction from the suspected bite?

Question #3: Was this really a NPPE?

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