Anesthesia Clinical question (Ketamine)

gotosleep · Jul 1, 2005

Ok, i have a clinical question for the SRNA's and CRNA's. The situation went like this. A patient came in to endoscopy with extreme anxiety and complaining of nausea. He had been NPO for 12 hours, the only thing he had had for 24 hours was his prep for colonoscopy. He received 2mg versed preop then 2mg more in the room, he had received 10mg of versed the previous week for EGD so it was recommended he get more than we usually use which is 2mg. He had a poor airway and was obese. To avoid using too much propofol he was given 20mg of Ketamine after his 4mg of versed and about 50mg of propofol. During the procedure he continued to move and received boluses of propofol totalling 200mg about 15-20minutes into the procedure. Then he started to make a gurgling sound and it was observed he was starting to cough. He was immediately suctioned and it appeared he vomitted. He was then bagged and suctioned until his sats become adequate and he woke up. Now my question is, could the ketamine have caused increased secretions enough to make him cough and vomit? This was an extremely nerve racking experience so it would be nice to hear some thoughts from experienced folks. Thanks.

maybe..

I like to use an antisialagogue with ketamine, especially with pediatrics.

Also, the combination of propofol (and versed and fentanyl) with ketamine, even in small doses is sufficient to depress laryngeal reflexes. I'm confused by the versed, ketamine, propofol cocktail. What is the purpose of using ketamine (considering half-life) if you intended on using propofol and versed?

CougRN · Jul 1, 2005

versed was used for his preop anxiety and for some sedation. the dose used was to help prevent emergence delerium from the ketamine. ketamine was only used in a small dose for anagesia and to prevent using more propofol. we normally use propofol, fentanyl, and versed for colons. ketamine is added at times in small doses to reduce the amount of propofol usage and prevent more respiratory depression.

gotosleep · Jul 1, 2005

versed was used for his preop anxiety and for some sedation. the dose used was to help prevent emergence delerium from the ketamine. ketamine was only used in a small dose for anagesia and to prevent using more propofol. we normally use propofol, fentanyl, and versed for colons. ketamine is added at times in small doses to reduce the amount of propofol usage and prevent more respiratory depression.

I just don't understand why you didn't use more ketamine as opposed to giving repeated boluses of propofol to a patient who "had a poor airway and was obese."

amberrn · Jul 1, 2005

I have not yet practiced, just 52 hours of class remain- but who's counting? Anyhow, yeah ketamine does increase secretions. As someone else said it seems to be more so in peds- at least that is what lecture has said.

versatile_kat · Jul 2, 2005

How old was the patient? I don't want to assume it was a pediatric patient, and didn't see it in your post.

One thing I've tried is a mix of Ketamine with Propofol (1:2) in the same syringe to decrease the risk of apnea ... just put it on an infusion pump. In fact, a great number of cosmetic surgery cases are done this way every day. Since the half life of Ketamine is only 11-17 min and you kept giving additional propofol throughout the procedure, your apnea seems to stem from the latter.

I wouldn't doubt the Ketamine caused your hypersalivation - but 20mg seems like a small dose (unless your patient only weighed 20kg, which I doubt since he was "obese") to cause that much trouble. Ketamine, in subhypnotic doses combined with propofol, is a beneficial adjuvant to MAC cases. What did the CRNA you were with think?

stevierae · Jul 2, 2005

I am wondering if, since he was obese, he may have also had GERD and /obstructive sleep apnea, and would have benefitted from a pre-op dose of Bicitra to neutralize stomach acids, as well as some Decadron, Anzemet or Zofran to cut down on the chance of N&V (either intraop or post-op.) Maybe some Atropine or Robinul pre-op, too, to dry up secretions.

(Not a CRNA, mind you; but an operating room nurse---hope you don't mind my input, for whatever it's worth.)

Also, if he had a poor airway (short; thick neck; perhaps a beard) and if he WAS an OBS patient, could he have worn his CPAP machine during the procedure? Then, if he did become apneic (could that gurgling you heard have possibly been snoring, or a breath kicking in after a brief period of apnea?) perhaps you could rely on the CPAP to kick in and trigger a breath before he desaturated too much, instead of having to insert an airway and ventilate him via mask or bag-valve-mask (if, indeed, you did?)

You didn't mention if you were using an LMA, or regular O2 via mask or nasal prongs before he desaturated.

mwbeah · Jul 2, 2005

Ok, i have a clinical question for the SRNA's and CRNA's. The situation went like this. A patient came in to endoscopy with extreme anxiety and complaining of nausea. He had been NPO for 12 hours, the only thing he had had for 24 hours was his prep for colonoscopy. He received 2mg versed preop then 2mg more in the room, he had received 10mg of versed the previous week for EGD so it was recommended he get more than we usually use which is 2mg. He had a poor airway and was obese. To avoid using too much propofol he was given 20mg of Ketamine after his 4mg of versed and about 50mg of propofol. During the procedure he continued to move and received boluses of propofol totalling 200mg about 15-20minutes into the procedure. Then he started to make a gurgling sound and it was observed he was starting to cough. He was immediately suctioned and it appeared he vomitted. He was then bagged and suctioned until his sats become adequate and he woke up. Now my question is, could the ketamine have caused increased secretions enough to make him cough and vomit? This was an extremely nerve racking experience so it would be nice to hear some thoughts from experienced folks. Thanks.

I use ketamine in over 75% of my cases (great preemptive analgesia). The dose you describe (more than likely) did not contribute to the scenario you describe.

Mike

jwk · Jul 2, 2005

Sure sounds like a general anesthetic to me. Several of us have pointed out problems to the RN's in the GI nurses section about the dangers of propofol use by non-anesthesia personnel. If the patient is NOT able to respond to you, you have moved from conscious sedation to deep sedation. Once you get to the loss of protective reflexes stage, you've hit general anesthesia in my book. Then you need to ask (or should have asked earlier), would you do a general anesthetic on this patient without an ETT? At least in most GI labs, these are supposedly MAC with conscious or deep sedation, not general anesthetics, unless planned that way ahead of time.

Don't let GI docs dictate YOUR anesthetic. Mike uses lots of ketamine, I don't use any, at least not for a GI case. Different strokes, not a problem. I use fent/versed/propofol on virtually all of my GI cases, but at a certain point, I tell the GI doc they've gotten enough from my standpoint. I do it MY way, or I don't do it. I have one doc who wants propofol only. Nope. That ain't the way I do it. You want to do it yourself, I'll be glad to leave. You want anesthesia here, I'm doing it my way. You do the black snake, I'll take care of the patient.

My favorite is "anesthesia, they're moving" (that's my name, anesthesia :chuckle ) I tell them this is NOT a general anesthetic, but if they'd like, I'll wake up the patient, get an anesthesia machine, put them back to sleep, put a tube in them, and they can play with their black snake for as long as they like and the patient will be absolutely still. Now of course Doctor, that will add about 45 minutes to your procedure, but hey, it's all about you, right? I'm still waiting for someone to take me up on that offer.

CougRN · Jul 2, 2005

I use ketamine in over 75% of my cases (great preemptive analgesia). The dose you describe (more than likely) did not contribute to the scenario you describe.
Mike

the crna i was with likes ketamine and so we used a little. i guess i didn't describe the scenario very well. the patient only recieved small doses of propofol after the ketamine and it was deep sedation. the patient was an adult and was not morbidly obese, just overweight. he received preop zofran. i understand not wanting to go to a GA for an endo case and the crna i was with did not think it was anything done by anesthesia that caused the problem. i was just wondering about small doses of ketamine and it's ability to cause enough irritation to result in vomitting. i appreciate the responses. i'm still learning.

CougRN · Jul 2, 2005

I just don't understand why you didn't use more ketamine as opposed to giving repeated boluses of propofol to a patient who "had a poor airway and was obese."

because the student isn't allowed to make all the decisions where i am. that's why i was looking for more input.

jwk · Jul 2, 2005

I use ketamine in over 75% of my cases (great preemptive analgesia). The dose you describe (more than likely) did not contribute to the scenario you describe.
Mike

Mike, assuming we're talking just about Gi cases here, how quickly are your ketamine patients ready for discharge? Ours are getting dressed within 15-20 minutes after the procedure and out the door.