Outpatient Surgery Magazine, providing current information on Surgical Services, Surgical Facility Administration, Outpatient Surgery News and Trends, OR Excellence and more.
Issue link: http://outpatientsurgery.uberflip.com/i/1275626
example, it is now well known that patients with Duchenne or Becker type muscular dystro- phy may develop life-threaten- ing or fatal hyperkalemia associ- ated with rhabdomyolysis when administered volatile agents or succinylcholine. Other types of rare diseases associated with muscle breakdown — such as CPT2 deficiency, McArdle's dis- ease or myoadenylate deami- nase deficiency — may be asso- ciated with rhabdomyolysis from administration of MH trig- gering agents. Some patients with a history of exaggerated rhabdomyolysis upon exposure to heat, exercise or administra- tion of statin medications, may be susceptible to either MH or these non-MH-related muscle breakdown reactions when they receive triggering anesthetics. MYTH #8: MH susceptibility can be ruled out with a genetic screening test FACT: Genetic screening is only useful when it reveals a known MH-causative variant because there are too many suspected MH variants that are yet unknown. At the present time, a known causative variant will be present in about 50% of biopsy-proven MH patients. That means the causative variant in the other half of the these patients is presently unknown and will remain undetected from a negative genetic screen. The only current and reliable way to rule out MH susceptibili- ty is by a negative contracture biopsy test. But this impractical method requires the patient to undergo a fresh muscle excision (usually from the thigh) at one of only five specialized sites in North America. MYTH #9: MH susceptible patients cannot be anesthetized in freestanding surgery centers FACT: Many clinicians believe that a patient who is known or suspected to be MH susceptible should not receive a trigger-free anesthetic in a freestand- 4 4 • O U T P A T I E N T S U R G E R Y M A G A Z I N E • A U G U S T 2 0 2 0 Dr. Litman (litmanr@email.chop.edu) is an anes- thesiologist at Children's Hospital of Philadelphia (CHOP) and a professor of anesthesiology and pedi- atrics at the Perelman School of Medicine at the University of Pennsylvania. ing surgical facility because the center will lack the resources to properly treat the reaction if it does occur. The chance that they will develop MH under these conditions is close to zero. On the other hand, many thousands of patients with unknown MH susceptibility receive triggering anesthetics daily. The chance that one of these patients will develop MH in a freestanding center, while rare, is still much higher than the patient with suspected or known MH susceptibility who receives a non-triggering agent. Many anesthesia providers avoid caring for these patients in freestanding centers due to fear of the unknown and the unwillingness (perhaps justified) to interfere with the normal throughput of the busy surgery schedule to complete the additional steps needed to safely care for these patients, such as thoroughly cleaning the anesthesia machine's breathing circuit and using total intravenous anesthesia. MYTH #10: Following an uneventful trigger-free anesthetic, MH susceptible patients should be observed for four hours in the PACU before discharge FACT: Many ambulatory surgical facilities will pro- long the discharges of MH susceptible patients for several hours to guard against a possible delayed postoperative reaction. This isn't necessary. We are not aware of any cases of delayed MH (see Myth #1), especially in patients who receive a non-trigger- ing anesthesia technique. MH susceptible patients who are recovering as expected after surgery can be sent home as soon as they meet normal dis- charge criteria. OSM FALSE NARRATIVE Younger patients are not more susceptible to MH, which is a genetic disorder that has nothing to do with age.