Porphyria Educational Services
PORPHYRIA EDUCATIONAL
SERVICES BULLETIN Vol. 1 No. 44
October 24, 1999 ~ FOCUS: Anesthesia and the
Porphyrias
Safety of general anesthesia and
surgery in the acute hepatic porphyrias has long been a
concern of the majority of porphyric patients.
Porphyric patients with the acute hepatic types of porphyria are
denied essential operations because of concern that general
anesthesia and surgery will precipitate a life threatening
porphyric crisis. In a study conducted at the Western Infirmary
in Glasgow, Scotland, a special study assessed the safety of
surgery under general anesthesia in acute porphyric
patients.
The study by Dover, McColl, Moore and Plenderleith which was
reported in 1994 issue of "Gut" medical journal, told
of a combined prospective and retrospective case note study, with
a biochemical study, which was conducted in 25
patients with acute hepatic porphyria undergoing 38 surgical
operations. Clinical outcome measures were survival and
occurrence of porphyric crisis after surgery.
The study the porphyric patients
were assessed by measurement of the preoperative 24 hour
excretion of the heme precursors delta amino- laevulinic acid (ALA)
and porphobilinogen (PBG)
There were no deaths or crises after 29 operations in 19 patients
who were known to have porphyria before their surgery, and
therefore given only appropriate drugs. These operations include
such major procedures as mitral valve replacement, hip
replacement, coronary artery grafting, cholecystectomies, and
renal transplantation.
In eight of these patients the urinary excretion of ALA and PBG
were studied, and showed no sustained postoperative increase.
Nine operations were performed in eight patients before the
diagnosis of porphyria was known and who thus received routine
anesthetic agents. The conclusion of the Scottish study is
that even the most major surgery can be undertaken safely in
patients with porphyria. The risk therefore is for undiagnosed
cases.
Presently in the United States the
anesthesia Versed [Midazolam] isbeing offered of the
anesthesia of choice for most surgeries and especially for
porphyric patients. It ha a very high safety record.
Most people do not even realize they hav been asleep let alone
drugged. There are no noticeableside effects or after
affects.
Versed is also an anesthesia that
works well together with the pain medication fentanyl which can
be administered intravenously as well.
Surgery for porphyic patients is no longer the problem it once
was.The real challenge is now to have the right anesthesia
for the latent porphyricpatients who is unaware of his or her
condition.