Can't I Eat or Drink Before My Surgery?
ensure your safety while under anesthesia.
been eating and have something go "down the wrong way"?
You probably coughed and gasped, and teared up and struggled
for breath, until the offending material was coughed back up
and cleared from your windpipe. This vigorous response
body is due to airway reflexes whose sole purpose in life is
to keep foreign material out of your air passages. Without
airway reflexes, nasty stuff would continually contaminate
our air passages, leading to serious complications, even
This mishap is known as aspiration.
of the effects of anesthesia is that these airway reflexes
suppressed so that they no longer function properly. This occurs
with almost every general anesthetic and can also occur
heavy sedation short of complete unconsciousness. Under these
circumstances, any material that happened to be in the stomach
could make its way up the swallowing tube (esophagus) in a
recumbent patient, and into the mouth, from where it is
a straight shot
into the windpipe (trachea) and into the lungs themselves.
Stomach contents are often highly acidic particles of partially
food, and this is just about the worst thing one can aspirate
into the lungs. Aspiration used to be one of the most frequent
and feared complications of anesthesia. Now it is a rarity
thanks to diligent attention to proper "nothing by
this reason we strictly enforce rules determining the consumption
of food and drink prior to surgery, so that the stomach is
as empty as possible at the time of
anesthetic induction. How long a period of time is required
for complete emptying of the stomach varies from patient to
patient and includes such factors as age, sex, pregnancy,
obesity, medications, and underlying medical condition. Often
we must make an informed judgement about when it is safe to
proceed. In doing so we take into account all of the above
factors, and consider the urgency of the surgery.
most strictly elective procedures we generally require eight
hours since the last consumption of solid food before anesthesia
can be induced. Liquids containing protein, fat, or particles,
such as milk or coffee creamer, are considered solids for the
purposes of this requirement.
liquids, loosely defined as a liquid you can "read
the newspaper through" can be consumed up to four
hours before surgery. Examples of clear liquids include
water, black coffee
or tea, clear sodas, or fruit juices without pulp or solids.
Soup or broth are considered solid foods because of the
of suspended solids and fat, which slows stomach emptying.
we treat ANY amount of solid-food consumption the same as
you have eaten an entire Thanksgiving dinner. We do so because
experience has shown us that patients often underestimate
much they have eaten, and we prefer to err on the side of safety
when such a serious matter is at hand.
emergency, life-saving surgery, without which the patient
be expected to suffer imminent injury or death, the risks of
delaying surgery to allow the stomach to clear outweigh
risk of proceeding with a potentially full stomach. In these
cases we take precautions to lessen the risk of aspiration
to decrease the chances that, should aspiration occur, any
injury should result from it. The determination of what
an emergency is a judgment that will be made jointly by your
surgeon and your anesthesiologist.
those procedures that are urgent but not emergent--which
to be done soon but which can wait long enough to empty the
stomach--we generally enforce the NPO rules outlined above.
drugs will I get with general anesthesia?
anesthesia involves the use of multiple different medications
that are chosen on a case-by-case basis by the anesthesiologists.
Decisions are made based on the patient characteristics,
on the length and type of surgical procedure. The majority
of the time, adults receive an intravenous induction agent,
as a short-acting barbiturate or sedative-hypnotic (usually
propofol). Maintenance of anesthesia is usually with a combination
of inhalational anesthetic agents (i.e., gases), opioid narcotics,
muscle relaxants and sedative hypnotic medications.
are the risks and side effects of anesthesia?
any medical procedure or drug, anesthetic drugs and techniques
come with potential side effects and risks, apart from the
risks of the operation itself. Some of these risks are quite
or even potentially fatal. Fortunately the more serious risks
are extremely rare. You are far safer statistically during
time you are under anesthesia than if you spent that same period
of time driving your car.
listing is not meant to be all-inclusive, so you must discuss
this subject with your anesthesiologist prior to your surgery.
He or she can better inform you of the
risks and side effects that are pertinent to the planned anesthetic
to mouth, lips, teeth, dental work, and other airway structures
during placement of airway-management devices
to eyes, ears, limbs, nerves, or genitals from positioning
to eyes from contact with hands or equipment, or from dryness
attack or stroke
reaction or adverse reaction to anesthetic drugs, fortunately
with or without vomiting
of stomach contents, leading to injury or death
extremely remote but finite chance
of the block to properly work. For various reasons sometimes
blocks do not work as planned. This will be determined BEFORE
surgery begins and alternate anesthetic methods will be used
to nerves blocked
in blood pressure or pulse (spinal or epidural anesthetics),
inconsequential for most patients
to the spinal cord or spinal nerves, resulting in partial
or complete paralysis
spread of spinal or epidural anesthetics, requiring life support
while the drugs wear off
injection of local anesthetics into the bloodstream, causing
seizures or heart rhythm problems, potentially fatal
drowsiness, respiratory depression, or temporary bladder or
bowel impairment from narcotics administered via the spinal
or epidural route
extremely remote but finite chance
will you know if I am really asleep?
or recall under anesthesia is a very disturbing and frightening
event, one which we strive to prevent. Fortunately, it is also
a rare event and tends to happen under certain special circumstances,
which we try to
anticipate and prevent wherever possible. These circumstances
usually have to do with an extremely ill patient who cannot
tolerate the usual doses of anesthetic drugs which provide
amnesia and unconsciousness. We are generally able to anticipate
this is the case and to take measures to provide amnesia and/or
encourage you to discuss your concerns about this important
topic with your anesthesiologist.