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MAKE SURE YOUR ANESTHESIOLOGIST USES A BIS !!!!

	It's every patient's worst nightmare: the
thought of having surgery without enough anesthesia;
of feeling the surgeon's knife but being unable to
tell anyone. While "intraoperative awareness" is
rare, it's not unheard of. The chance of "awareness"
is now even smaller at hospitals that have installed
a new brain-wave monitoring system in their
operating rooms.
	Dr. Andrew Bowdle, associate professor of
anesthesiology at University of Washington Medical
Center, which has installed the system in all of its
operating rooms says, "There are very few statistics
on intraoperative awareness. It happens occasionally,
and when it does, it's devastating for the patient.
This monitor goes a long way toward preventing it."
	The new system, called the Bispectral Index,
offers the first direct way to measure the effects
of anesthetic on the brain, using an enhanced EEG
(electroencephalogram) monitor.
	Bsides displaying EEG data, the system
analyzes the patient's brain wave pattern and
converts it into a "depth of sedation" number between
0 (indicating no brain activity) and 100 (fully awake).
The target number for an surgical patient is 50 to 60.
	The new system offers a number of advantages
in addition to calming patients' fears about inadequate
anesthesia, said Bowdle. There are significant cost
savings from being able to give the right amount of
anesthetic drugs. Without the system, anesthesiologists
may give more drugs than necessary to make sure their
patients are completely unconscious during surgery.
Without the extra depth of anesthesia, patients also
awaken more quickly after surgery.
	No preparation of the skin is needed other than
an alcohol wipe, so the anesthesiologist can quickly
attach the electrodes. "There was a lot of skepticism
about this system when it was first offered," said Bowdle.
"People have been trying to use EEGs to monitor
anesthesia depth for 20 years. But clinical trials have
shown that this accurately measures the depth of sedation
by direct, noninvasive means. We would use this system
even if it weren't reducing costs, because of its ability
to reduce intraoperative awareness and shorten recovery
time."
	Unexpected wakeups occur in at least 40,000 of
the country's 20 million annual surgeries, according to
Dr. Peter Sebel, an anesthesiologist at Emory University,
who has studied the problem. In most cases, the pain-killers
keep working and the patient feels only pressure. But Sebel
estimates that in at least 400 cases annually, patients
actually feel pain.

http://www.hslib.washington.edu/your_health/hbeat/hb980113.html

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	February 17, 1998 - It's a cause of great anxiety
for patients undergoing surgery. Recent, publicised reports
of surgical patients who unexpectedly regain consciousness
but are unable to communicate have anesthesiologists
searching for ways to gauge drug doses more accurately.
	A new device, the Bispectral Index (BIS), is being
introduced at Strong Memorial Hospital to help doctors
judge drug doses to prevent patients from regaining
awareness in the operating room. A flexible sensor which
attaches to the patient's forehead records brain waves with
a specialised EEG machine, giving anesthesiologists a
direct measure of how deeply the patient is asleep.
	Studies have shown that monitoring patients with
the BIS results in improved patient outcomes, including
better overall recovery and more alert patients in the
recovery room.
	Doctors have relied on blood pressure and other
vital signs to monitor sleep level during surgery but this
method only measures the effect of pain-killers - not the
full combination of pain-killers, sedatives and paralytic
drugs used to induce anaesthetised sleep. True sleep level
can only be measured through brain waves.
	"With this equipment, anesthesiologists can now
give the precise amount of drug to ensure that patient
does not regain consciousness," said Ronald Litman,
director of pediatric anesthesiology at Strong Memorial
Hospital.
	To avoid the chance of patient awareness during
surgery, anesthesiologists usually give slightly more
anesthetic than needed. "Essentially, the BIS lets us
customise anesthesia to the particular patient, which
could be especially useful in children's surgeries,"
Litman said.
	Studies conducted at Emory University estimate
that unexpected wake-ups occur in at least 40,000 of the
nation's 20 million surgeries. In most cases, pain-killers
continue to work, but the patient becomes aware of his or
her surroundings.