Ketamine drips post op for chronic pain pts

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Have you seen this before? I can't find a decent body of evidence-based literature on the topic.

I work in orthopedic surgery, and see this used relatively often. I am not a fan because, unlike the typical post-op delirium or opiate-related confusion that I see, I feel like my patients are living out their worst nightmares. From literature and text I see that it's used in anesthesia and status epilepticus. I have never personally seen it used for these things, but I have had many many patients on Ketamine drips.

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Specializes in ICU/ER.

Our docs no longer use Ketamine-- I had an interesting talk with my vet and he is a fan of it...funny. From a few of the pts I took care of that were on Ket I wonder why it is a popular street drug as it seemed like they did not enjoy themselves at all!!! granted they were post op!! ---I do know that one of the pre-op questions asked is "do you suffer from PTSD and were you abused as a child---" this would have been a rule out question for this drug. I do know that Ketamine CRI should always be preceded by an opioid agent.

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Specializes in critical care, med/surg.

I recently read an article in Chest about using Ketamine in sub anesthesia doses in combination with smaller doses of morphine to alleviate postop pain in thoracic surgery. I gave it to our thoracic docs in hopes that we could begin a trial since it supposedly reduced ICU time, ICU psychosis and decreased LOS overall, but haven't heard back. I get so frustrated when pts wig out on morphine, get placed in a coma with dilaudid, are assaulted with demerol and need to be restrained all because of pain issues!

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Specializes in PCU (Cardiac).

Interesting, I thought it was used more for anesthesia and by vets.

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Thanks for your replies! Just a little more info--Racing, all our patients on Ketamine do have a narcotic infusion as well--usually a high-dose PCA dilaudid, sometimes with a continuous infusion. Organic, I'd be interested in reading that article in CHEST. In my experience, the side-effects w/ Ketamine are worse than w/ only narcotics because of the hallucinations/psychosis. Some docs and nurses like it since it tends to keep the BP from bottoming out--a valid benefit since a lot of these patients are on so much IV narcotic already. These patients also tend to stay a little longer since their pain is generally more of an issue, and they have a harder time getting moving. I'm sure their state of mind on Ketamine doesn't help w/ their physical therapy progress :zzzzz

At the same time, I have started patients who are having intractable surgical pain on Ketamine who experienced relief. But I find that in general, the brain effects of the drug make it's value questionable.

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Specializes in Anesthesia.

Ketamine is most likely being used to reduce the overall dose of opioids in your patients. Ketamine has been shown to prevent and reverse morphine induced opioid tolerance. It also helps preserve respiratory/CV function in patients. Recommended doses are around 0.3mg/kg/hr, but doses will vary by patient.

I would hope that your patients would have prn benzos for delirium.

Do you know what dosage of ketamine your patient's are getting?

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according to this blurb, its effects are remarkable....including mild, absent se's.

Peri-operative Ketamine for acute post-operative pain: a quantitative and qualitative systematic review

http://www.ncbi.nlm.nih.gov/pubmed/16223384

leslie

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Specializes in Hospice.
Ketamine is most likely being used to reduce the overall dose of opioids in your patients. Ketamine has been shown to prevent and reverse morphine induced opioid tolerance. It also helps preserve respiratory/CV function in patients. Recommended doses are around 0.3mg/kg/hr, but doses will vary by patient.

I would hope that your patients would have prn benzos for delirium.

Do you know what dosage of ketamine your patient's are getting?

Benzos for delirium? In my experience, benzos - especially ativan - often aggravate delirium. Is there something about ketamine-induced delirium that makes it amenable to benzos? I'm more likely to see a haldol order for sx of delerium (variable loc, periods of lucidity alternating w/ periods of confusion, hallucinations and delusions)

Am I missing something?

End of derail ... back to your regularly scheduled thread ...

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Specializes in Anesthesia.
Benzos for delirium? In my experience, benzos - especially ativan - often aggravate delirium. Is there something about ketamine-induced delirium that makes it amenable to benzos? I'm more likely to see a haldol order for sx of delerium (variable loc, periods of lucidity alternating w/ periods of confusion, hallucinations and delusions)

Am I missing something?

End of derail ... back to your regularly scheduled thread ...

Benzos in this case are specifically being used to treat/counteract the emergence delirium caused from ketamine. This is not your normal delirium that you see with older patients coming out of anesthesia. Haldol or other antipsychotics would more than likely just increase the symptoms caused with ketamine. In this case the benzos are used more as an anxiolytic. Keeping the ketamine at doses as low as possible that still keeps the patient comfortable is the best way to prevent "emergenence delirium".

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As far as dosing goes, I have given between 0.1-0.3 mg/kg/hr--usually 0.2. And these replies makes perfect sense, theoretically. Whenever we take care of patients on ketamine drips, respiratory and CV function is definitely not our greatest issue (even though the amount of opiate in the patient is great). Preventing and reversing opioid tolerance also makes sense.

That Ncbi blurb is pretty interesting--in practice, the SEs (besides CV) are terrible. post-op n/v seems just as prevalent, and mental SEs are awful. Granted, these patients aren't completely delirious--if they try to get out of bed, they just need reminding of where they are, and they settle down. They tell you they're hallucinating, they don't know if they're dreaming, and that they feel miserable and foolish. While the self-awareness helps to keep them safe, I wouldn't wish this state on anyone.

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