Clinical discussion... as requested!

i think, at the very least, a further inquiry into child's risk of developing malignant hyperthermia is justified before proceeding with the tube placement. as healthcare PROFESSIONALS we often need to educate patients about risks and benefits of treatment. while having a child who is miserable with ear infections is difficult - so is planing a funeral for a child after a tragic outcome of an ELECTIVE procedure.

No way I am going to take the liability for this case so I would call the MDA to deal with it.

1. Only after consulting further w/ parents, surgeon, and another anesthesia provider.

2. "The Caffeine Halothane Contracture Test (CHCT), a test performed on freshly biopsied muscle, is the “gold standard” for diagnosis of MH." http://www.mhaus.org/index.cfm/fusea...DB27999FE5.cfm

3. What Drugs trigger MH and are Not Safe?

Inhaled General Anesthetics
Choroform (Trichloromethane, Methyltrichloride)

Desflurane

Enflurane

Halothane

Isoflurane

Methoxyflurane

Sevoflurane

Trichloroethylene

Xenon (Rarely Used)

Depolarizing Muscle Relaxants Trigger MH
Succinylcholine (Suxamethonium)

Also, soda lime, breathing tubes, and breathing bags should be new since trace amounts could be detrimental to the patient or changed out immediately if MH is suspected.
http://www.mhaus.org/index.cfm/fusea...theticList.cfm

4. Treatment is dantrolene, ventilation with 100% O2, and cooling measures if fever is present.

5. "MH or MH-like events however, have occurred in patients with underlying muscle diseases, such as muscular dystrophy and myotonia. Such patients typically display muscle weakness. MH has been linked to a rare disorder of muscle called Central Core disease and King Denborough Syndrome, a rarer muscle syndrome.
Additionally, patients with certain forms of muscular dystrophy may develop life-threatening disturbances and muscle destruction on exposure to the triggering agents for MH. The clinical event may resemble MH in many ways, but is not considered “true” MH. In patients with Duchenne muscular dystrophy, succinylcholine should always be avoided or rhabdomyolysis may occur. Potent volatile agents may produce rhabdomyolysis in time, but most believe that brief exposure is a small risk. Patients with muscle disorders should be carefully evaluated by their anesthesiologist prior to surgery.
Hypokalemic and hyperkalemic periodic paralysis are also associated with risk for MH. Hyperkalemic cardiac arrest may occur when MH-trigger agents are administered to muscular dystrophy patients.
Patients with osteogenesis imperfecta often develop fever during anesthesia. Myotonic patients will develop muscle rigidity with succinylcholine. There have been a few MH cases reported in patients with carnitine palmityl transferase deficiency and it is recommended to stay away from MH triggers in such patients. Neuroleptic Malignant Syndrome (NMS) is a syndrome that resembles MH but is precipitated by drugs acting centrally on dopaminergic pathways in the brain." http://www.mhaus.org/index.cfm/fusea...edicalFAQs.cfm

Great Questions!!

Keep 'em coming I start CRNA school next month!

According to the link http://www.intelihealth.com/IH/ihtIH...339/24695.html the possible presence of genetic MH can only be tested at a few labs in the country and is done by muscle biopsy. (Further complicating matters is that the muscle sample must be fresh, alas, the pt must BE there for the test.)

Most of your other questions are also answered here. (I'd be curious if their answers follow a standard protocol of sorts.)

Hmm, non-triggering anesthetic in a two year old? My guess is that you gave him a healthy dose of po versed, maybe with some fentanyl, and got him relaxed enough that you could get an iv in him, then used propofol gtt while masking him (with adequately flushed machine, new circuit & absorbers) with n20/O2 for the placement of the tubes? am I close?

Good scenario. I have seen one case of MH and it is something I will never forget. It is my understanding that any agent can trigger MH, but it is mostly seen with succinylcholine.

This will not make me popular, but I don't work with anesthesiologists, so I assume my own liability. Nurses talk WAY too much about legal issues. I am very diligent and administer good anesthesia and am not worried about lawsuits or protecting my license.

Ali

We've done them as a local only after po versed...and done a o2/n2o mask for iv then propofol as a tiva.