From: ME.DMG@forsythe.stanford.edu (David Gaba M.D.)
Subject: Risks of anesthesia
Organization: Stanford University, California, USA
Date: Sun, 27 Sep 1992 00:58:15 GMT

In response to some of the questions concerning anesthetic risk
for both epidural and general anesthesia:

This is an extremely complex question.  First of all, one has to
define whether one is talking about "young healthy patients" vs.
patients with underlying medical diseases.  Incidentally, while
pregnancy is "normal" from an evolutionary standpoint, it certainly
alters some physiologic factors in women that makes them more
vulnerable to certain risks of surgery and anesthesia.

Second, it is quite rare to have anesthesia without surgery.  There
are a number of combined risks in which both surgical factors
and anesthesia factors play a role.  This can be especially true
for chidbirth where both physicians involved are treating two
patients simultaneously -- sometimes with conflicting goals
(i.e. what's safest for the mother could impart risks to the
fetus, and vice versa).  Separating out the "causes" of adverse
outcomes in any study is extremely difficult.

Third -- it has become nearly impossible in the US to conduct
an appropriate prospective study of anesthetic and surgical
complications, in part because of the connection between such
events and litigation.  This makes it difficult to acquire
full and open data about any such events.

Extrapolating from older studies the "standard" risk figure for
ALL patients having surgery (old&young, sick and healthy) and
for catastrophic (death or brain damage) outcomes due SOLELY to
"anesthesia" is 1:10,000.  A more recent study in Britain gives
1 in 180,000 surgical cases resulting in a DEATH solely from
anesthesia (that 1 in the study was in an emergency appendectomy)
and 1 in 1800 due to some combination of factors including
anesthesia (others being underlying medical or surgical disease
state, surgery itself, etc.).

However, the overall risk of all negative outcomes is unknown,
and the accuracy of the British figures to the US (or to larger
areas of Britain than the original study) is uncertain.

As to general anesthesia vs. regional (epidural, spinal, or major
nerve block) overall the risks of minor problems and for
catastrophes is thought to be about equal.  Certain combinations of
underlying diseases, and surgical operations will provide
for the possibility that one approach is safer than the other
in the hands of a given individual (who like all professionals
will be somewhat more skilled in different kinds of procedures).
We anesthesiologists spend a lot of time deciding what approach
(and all its sub-issues) would be best for each individual patient
and surgery.

For childbirth, for pain relief from labor, clearly regional
anesthesia with relatively low concentrations of epidural
local anesthetics is the most effective choice, assuming that
"natural" techniques are insufficient (quite common!).  Yes there
are risks but overall the rate is extremely low.

For C sections, it depends on many factors, including how urgent the
C Section is, and the presence or absence of other underlying
problems (like clotting abnormalities which can arise during
certain pregnancy complications).  Most elective and unplanned but
not urgent/emergent C sections are done under epidural (or spinal)
anesthesia, in large measure because most delivering mothers
prefer to be awake to experience the birth.  It is probably safer
than general anesthesia because during pregnancy the emptying of
the stomach is affected and the mother may be at risk for
aspirating vomit into the lungs during a general anesthetic to a
much larger degree than in other age-matched healthy people. (Still
a relatively uncommon event nonetheless).

For people facing surgery or childbirth who have questions about
anesthesia, the most important thing they can do is have a serious
conversation with an anesthesiologist concerning these issues and
to discuss the different alternatives that are available.

Incidentally, the anesthesia profession has a very active program
of research and education concerning improving patient safety.
Anyone interested in finding out about such programs can
contract the Anesthesia Patient Safety Foundation at:

520 N. Northwest Highway
Park Ridge, IL 60068-2573
708 825 5586
Fax -- 708 825 1692

***** STANDARD DISCLAIMER********

The above is for information only and does NOT constitute
giving medical advice

************************************

David Gaba, M.D., Assoc. Prof of Anesthesia (with Tenure)
                  Stanford University School of Medicine

Newsgroups: sci.med