Clinical case for discussion

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Gern Blansten

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Three year old male presents for BMT, tonsillectomy and adenoidectomy for treatment of recurrent ear infections and URIs. He finished a round of zithromax 2 days ago and was noted by parents to have a temp of 103.5 three days ago. His current temp is 99.5 with clear lung fields and no productive cough or any other evidence of URI.

His past medical history is otherwise unremarkable. His family history is positive for a grandfather who had documented malignant hyperthermia 15 years ago. Grandfather on the other side of the family is a physician who happens to be president of a major medical organization in your state.

Describe how you would approach the anesthetic management of this patient.

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Prep: Set up a propofol pump, and change the vent circuit to a MH ready one that has had no volatile exposure, and run high flow (10 L) O2 for 20 minutes to clear circuit/machine. Get everything else ready as usual.

Pre-op: versed PO

OR: Standard monitors, N2O, IV start in OR, start propofol pump, bag-mask ventilate, fentanyl, LTA, intubate when extremely deep, or use Roc. Try to extubate in the OR, but not mandatory. May extubate in PACU to expedite OR turnover.

PACU: No differences, except extra caution to oversedating b/c u don't want anyone to miss the MH and take a whack at reintubating w/SCH.

Considerations
1. Recent completion ABX for URI. At any given time a kid has ~ 80% chance of having an URI w/i one mo, so guidelines are usually pointless. Instead, most people recc looking at clinical sn, symptoms, and studies. If Ok looking now, then go. Especially BMT's, the procedure is a Tx so it doesn't really matter if they have an active URI b/c that is what they are treating.

2. MH: Pt is at increased risk, and tf must be treated as if they have it. No use in recc Bx unless you want to be laughed out of the OR.

3. Pt VIP status: Who cares. All my pt are treated as if they are my bro, sis, mom, dad, granny, gramps. If you have a personality issue, try to be diplomatic so u don't get your group under the microscope.
 
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Three year old male presents for BMT, tonsillectomy and adenoidectomy for treatment of recurrent ear infections and URIs. He finished a round of zithromax 2 days ago and was noted by parents to have a temp of 103.5 three days ago. His current temp is 99.5 with clear lung fields and no productive cough or any other evidence of URI.

His past medical history is otherwise unremarkable. His family history is positive for a grandfather who had documented malignant hyperthermia 15 years ago. Grandfather on the other side of the family is a physician who happens to be president of a major medical organization in your state.

Describe how you would approach the anesthetic management of this patient.

1. Take more history and decide whether this patient has undergone appropriate treatment of his URI. Clinically, he looks good to go without any physical exam findings, although you didn't mention any room-air saturation. I assume it would be normal.

2. Explain to the family that confirmatory testing for MH is expensive and not really worth it. Has this patient had anesthesia before...if so, look at the records.

3. Regardless, I would probably do a nontriggering anesthetic.

4. Preop versed and/or ketamine orally....a good dose because inhalational induction is out and we need an IV. Lidoderm patch over a vein in the hand. To OR once premed is optimized. N20 70%. IV. Oral RAE. Propofol/Fentanyl maintenance. Minimal narcotics especially if patient has OSH. Good suction at the end and deep extubation.

5. Post-op visit and shake hands with the grandfather.
 
He finished a round of zithromax 2 days ago and was noted by parents to have a temp of 103.5 three days ago. Grandfather on the other side of the family is a physician who happens to be president of a major medical organization in your state.

If he allowed abx for uri then you should get away with giving sevo even if MH susceptible. :thumbdown:

Anyway put EMLA on a vein >2h before surgery and have wiped of 15min before so you don't get the vasoconstriction.
N2O prop narcs tube.
 
Try to extubate in the OR, but not mandatory. May extubate in PACU to expedite OR turnover.

PACU: No differences, except extra caution to oversedating b/c u don't want anyone to miss the MH and take a whack at reintubating w/SCH.

Screw turnover. I'm pulling that tube when I want to, wherever I want, which happens to be in the OR.
 
Important question: While his grandfather is known to be MH susceptible, are either of his parents known to be MH negative on muscle biopsy? If the parents are not MH susceptible, the kid won't be either, in otherwords, MH doesn't skip generations. I'm taking Jensen's review course right now, and here's the "Lock and Load" straight out of Big Blue:
"There has never been a reported case of MH susceptibilty skipping a generation (such as a grandparent who is positive, parents who are negative with positive grandchild)."

If the parents are of unknown susceptibility, I'd do a non-triggering technique, but if they are confirmed negative, triggering agents are ok.
 
Important question: While his grandfather is known to be MH susceptible, are either of his parents known to be MH negative on muscle biopsy? If the parents are not MH susceptible, the kid won't be either, in otherwords, MH doesn't skip generations. I'm taking Jensen's review course right now, and here's the "Lock and Load" straight out of Big Blue:
"There has never been a reported case of MH susceptibilty skipping a generation (such as a grandparent who is positive, parents who are negative with positive grandchild)."

If the parents are of unknown susceptibility, I'd do a non-triggering technique, but if they are confirmed negative, triggering agents are ok.

Would you take the parents word for it or would you require copies of the testing results as proof? Just curious. Perhaps the reason that there are no reported cases is that most discerning people who know there is a family history administer a non-triggering anesthetic agent. I don't know, but it seems reasonable.
 
1. NO to doing case free standing surgical center.

This issue has been discussed with my colleagues. If you are using a non-triggering anesthetic, should it matter? I understand the anxiety associated with it, but is it justified if no triggering agents are used?
 
To add a twist, the CRNA that is helping with the case, prior to discussing the case with you, has set up for an inhalation induction and states that "it is just the grandfather who had MH, so they are probably fine for an inhalation induction."
What would your response be?
 
Would you take the parents word for it or would you require copies of the testing results as proof? Just curious. Perhaps the reason that there are no reported cases is that most discerning people who know there is a family history administer a non-triggering anesthetic agent. I don't know, but it seems reasonable.

I'm sort of playing the little academic devil's advocate a bit here... :D yes, there are definitely known false positive and negative biopsies in the literature (which Jensen points out as well), and nowadays it's all PCR, which I'm guessing has far less false results than the old muscle biopsies. Would I have the cajones to go with a triggering anesthetic in a scenario where mom and dad said 'Here's both our negative muscle biopsy and PCR results from Mayo'? Less than a month out from residency here, and with the ease of do a non-triggering technique, I'd have no good reason to push my luck. But I'm sure there are plenty of people out there who would think it's not totally insane to use volatile agents in that situation, and they would be backed by current best evidence.
 
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I'm sort of playing the little academic devil's advocate a bit here... :D yes, there are definitely known false positive and negative biopsies in the literature (which Jensen points out as well), and nowadays it's all PCR, which I'm guessing has far less false results than the old muscle biopsies. Would I have the cajones to go with a triggering anesthetic in a scenario where mom and dad said 'Here's both our negative muscle biopsy and PCR results from Mayo'? Less than a month out from residency here, and with the ease of do a non-triggering technique, I'd have no good reason to push my luck. But I'm sure there are plenty of people out there who would think it's not totally insane to use volatile agents in that situation, and they would be backed by current best evidence.

I'm with you - I'd still go the non triggering route, it's not as if it's really that hard now. Get enough nitrous on board and you can put an IV in anyone without them noticing.

As to the PCR - I wouldn't consider someone who is PCR negative to be not MH susceptible in the absence of the POSITIVE PCR result for their MH affected relative, because of the significant genetic herterogeneity. There is only 1 confirmed gene associated with MHS (RYR1 - and this is therefore the only one that can have PCR diagnosis associated with it) but OMIM lists 5 other loci that have been mapped within families with MH that do not map to the RYR1 gene. Those that are found to be RYR1 mutants also need to have one of the already characterised mutations that is confirmed to cuase MH susceptibility for PCR testing to be advantageous in their family members.

In short - I would take a negative PCR result with a very large grain of salt as by itself it proves nothing with regards to the patients chances of developing MH under anaesthesia.
 
To add a twist, the CRNA that is helping with the case, prior to discussing the case with you, has set up for an inhalation induction and states that "it is just the grandfather who had MH, so they are probably fine for an inhalation induction."
What would your response be?

Given that patients who develop MH have often had an uneventful anaesthetic prior to their episode of MH, the only why of knowing whether or not the child is NOT MH susceptible is negative muscle biopsies from both parents or a negative muscle biopsy from the child. In the absence of either of these pieces of information, the child should be considered MH susceptible as the probability of the child being MH susceptible with an MH susceptible grandparent and unknown parent status is 25%. I would consider that an unacceptably high probability to use a known triggering agent. Therefore this child does not get volatiles or sux. And if that means that we have to delay the list for 20min to change the set up and flush the machine, then we delay the list.
 
:confused:
I am not sure I understand what you are saying here!
Could you help me out?

The fact that the grand father is a doc doesn't make the medical management of the kind any better since he's been treated with abx for an upper respiratory infection which is more than likely viral and self limited.
 
The fact that the grand father is a doc doesn't make the medical management of the kind any better since he's been treated with abx for an upper respiratory infection which is more than likely viral and self limited.

...or maybe they were just covering their bases since he developed these Sx a week before his scheduled BMT.
 
To add a twist, the CRNA that is helping with the case, prior to discussing the case with you, has set up for an inhalation induction and states that "it is just the grandfather who had MH, so they are probably fine for an inhalation induction."
What would your response be?

My response would be: NO
 
I know the guidelines allow this. I guess that I am thinking about our local battles with surgeons. We have a surgicenter that we practice at less than 10 miles from a children's hospital that is part of the same health care system that all our surgeons have privileges at. Drives us crazy when for convenience sake they schedule a kid with a significant history at the ASU.

We have the same issues with our surgeons, however, I think that, given this child's negative pulmonary exam and the non triggering anesthetic, I would be okay with the ASC. However, I might flush the machine a bit longer than recommended and I would definitely use an end tidal gas monitor to check the system for 10 minutes to make sure no trace gases showed up in the system. I definitely understand your point though.
 
The way I managed the case is similar to some of the suggestions made here. Long preop discussion with family regarding the non triggering anesthetic. Machine prep and checkout to ensure no trace volatile anesthetic, preop midazolam and ketamine made the child very easy to manage. A bit of nitrous for the IV start and propofol/ rocuronium for induction. Propofol/fentanyl/O2/N2O mix for maintenence. A 45 minute PACU stay with orders that clearly stated MH susceptibility and verbal communication that if reintubation became necessary(unlikely), no succinylcholine would be used. A temp check at arrival and discharge from PACU was normal.
Then a brief visit with family to reassure that everything went well.

With regards to the family member who was a physician. He was very appropriate with me, however, he seemed to throw his weight around with the nursing staff who were intimidated by him. It bothers me when family in high places put special demands on the providers and act in this manner. It changes the focus (for some) from caring properly for the patient to catering to the VIP status of the family member. I have never seen it help in a positive way, but I have seen routines disrupted that cause lapses in care that would not have occurred had the normal routine been followed.
 
Cool case...I just don't understand the need for rocuronium. Where I train, we have a very busy ENT service, and I would say muscle relaxants are almost universally never used for PET/T&A's. What dose do you use? Why do you use it? Do you reverse everyone with full dose neostigmine/glyco?

The way I managed the case is similar to some of the suggestions made here. Long preop discussion with family regarding the non triggering anesthetic. Machine prep and checkout to ensure no trace volatile anesthetic, preop midazolam and ketamine made the child very easy to manage. A bit of nitrous for the IV start and propofol/ rocuronium for induction. Propofol/fentanyl/O2/N2O mix for maintenence. A 45 minute PACU stay with orders that clearly stated MH susceptibility and verbal communication that if reintubation became necessary(unlikely), no succinylcholine would be used. A temp check at arrival and discharge from PACU was normal.
Then a brief visit with family to reassure that everything went well.

With regards to the family member who was a physician. He was very appropriate with me, however, he seemed to throw his weight around with the nursing staff who were intimidated by him. It bothers me when family in high places put special demands on the providers and act in this manner. It changes the focus (for some) from caring properly for the patient to catering to the VIP status of the family member. I have never seen it help in a positive way, but I have seen routines disrupted that cause lapses in care that would not have occurred had the normal routine been followed.
 
Cool case...I just don't understand the need for rocuronium. Where I train, we have a very busy ENT service, and I would say muscle relaxants are almost universally never used for PET/T&A's. What dose do you use? Why do you use it? Do you reverse everyone with full dose neostigmine/glyco?

Agreed. Probably not necessary if you use adequate propofol, fentanyl, and lidocaine. I normally would not use anything other than deep volatile anesthetic in these cases, but, for obvious reasons, didn't in this case. As we all learn, there are numerous acceptable ways to deal with most cases.
 
Given that patients who develop MH have often had an uneventful anaesthetic prior to their episode of MH, the only why of knowing whether or not the child is NOT MH susceptible is negative muscle biopsies from both parents or a negative muscle biopsy from the child. In the absence of either of these pieces of information, the child should be considered MH susceptible as the probability of the child being MH susceptible with an MH susceptible grandparent and unknown parent status is 25%. I would consider that an unacceptably high probability to use a known triggering agent. Therefore this child does not get volatiles or sux. And if that means that we have to delay the list for 20min to change the set up and flush the machine, then we delay the list.

:thumbup::thumbup:
 
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