Anesthesia Related Complications
Anesthesia - Risks and Complications
"Although all types of anesthesia involve some risk, major side effects and complications
from anesthesia are uncommon. Your specific risks depend on your health, the type of
anesthesia used, and your response to anesthesia. Prior to planned operation or procedure,
the anesthetist or anesthesia doctor reviews the medical record and/or interviews the
patient to determine the best combination of drugs and dosages and the degree to which
monitoring will be required to ensure a safe and effective procedure. Key factors of this
evaluation are the patient's age, body mass index (BMI) medical and surgical history,
current medications, and fasting time. Thorough and accurate answering of the questions
is important so that the anesthetist can select the proper anesthetic drugs and procedures.
For example, a patient who consumes significant quantities of alcohol or illicit drugs
could be undermedicated if s/he fails to disclose this fact. This in turn could then lead to
anesthesia awareness or dangerously high blood pressure. Commonly used medications
(e.g., sildenafil) can interact with anesthesia drugs; failure to disclose such usage can also
increase the risk to the patient. There are some situations (where patients are on a certain
medication and must undergo a given procedure) in which local anesthesia or regional
anesthesia can be given, but instead general anesthesia is chosen, though this is not
extremely common due to the fact that general anesthesia is by nature more dangerous
and the agents used react with many more medications.
An important aspect of the preanaesthetic evaluation is that of the patient's airway,
involving inspection of the mouth opening and visualization of the soft tissues of the
pharynx. The condition of teeth and location of dental crowns and caps are checked, neck
flexibility and head extension observed. If a tracheal tube is indicated and airway
management is deemed difficult, then alternative methods of tracheal intubation, such as
fiberoptic intubation, may be required as part of the anesthetic management.
Personal risk factors
Your age may be a risk factor. In general, the risks associated with anesthesia and surgery
increase in older people.
Certain medical conditions such heart, circulation, or nervous system problems, increase
your risk of complications from anesthesia.
Some medicines can raise your risk of problems too. Patients are encouraged to make a
list of all their prescriptions and over-the-counter medicines you take. To share with their
doctors and anesthesia team.
If you smoke, drink alcohol, or use illegal drugs, you may be more likely to have
problems from anesthesia. It's important that you are honest when you talk with your
surgeon and anesthesia specialist.
Complications from local anesthesia
When used properly, local anesthetics are safe and have few major side effects. But in
high doses, local anesthetics can have toxic effects caused by being absorbed through the
bloodstream into the rest of the body (systemic toxicity). This may significantly affect
your breathing, heartbeat, blood pressure, and other body functions. Because of these
potential toxic effects, equipment for emergency care must be immediately available
when local anesthetics are used.
Complications from regional anesthesia
For regional anesthesia, an anesthetic is injected close to a nerve, a bundle of nerves, or
the spinal cord. In rare cases, nerve damage can cause persistent numbness, weakness, or
pain.
Regional anesthesia (regional nerve blocks, epidural and spinal anesthesia) also carries
the risk of systemic toxicity if the anesthetic is absorbed through the bloodstream into the
body. Other complications include heart or lung problems, and infection, swelling, or
bruising (hematoma) at the injection site.
Spinal anesthesia medicine is injected into the fluid that surrounds the spinal cord
(cerebral spinal). The most common complication of spinal anesthesia is a headache
caused by leaking of this fluid. It is more common in younger people. A spinal headache
may be treated quickly with a blood patch to prevent further complications. A blood
patch involves injecting a small amount of the person's own blood into the area where the
leak is most likely occurring to seal the hole and to increase pressure in the spinal canal
and relieve the pull on the membranes surrounding the canal.
Complications from general anesthesia
Serious side effects of general anesthesia are uncommon in people who are otherwise
healthy. But because general anesthesia affects the whole body, it is more likely to cause
side effects than local or regional anesthesia. Fortunately, most side effects of general
anesthesia are minor and can be easily managed.
General anesthesia suppresses the normal throat reflexes that prevent aspiration, such as
swallowing, coughing, or gagging. Aspiration occurs when an object or liquid is inhaled
into the respiratory tract (the windpipe or the lungs). To help prevent aspiration, an
endotracheal tube (ETT or ET tube) may be inserted during general anesthesia. When an
ET tube is in place, the lungs are protected so stomach contents cannot enter the lungs.
Aspiration during anesthesia and surgery is very uncommon. To reduce this risk, people
are usually instructed not to eat or drink anything for a certain number of hours before
anesthesia so that the stomach is empty. Anesthesia specialists use many safety measures
to minimize the risk of aspiration.
Insertion or removal of airways may cause respiratory problems such as coughing;
gagging; or muscle spasms in the voice box, or larynx (laryngospasms), or in the
bronchial tubes in the lungs (bronchospasm). Insertion of airways also may cause an
increase in blood pressure (hypertension) and heart rate (tachycardia). Other
complications may include damage to teeth and lips, swelling in the larynx, sore throat,
and hoarseness caused by injury or irritation of the larynx.
Other serious risks of general anesthesia include changes in blood pressure or heart rate
or rhythm, heart attack, or stroke. Death or serious illness or injury due solely to
anesthesia is rare and is usually also related to complications from the surgery. Death
occurs in about 1 out of 200,000 healthy people who get anesthesia.
Some people who are going to have general anesthesia express concern that they will not
be completely unconscious but will "wake up" and have some awareness during the
surgical procedure. But awareness during general anesthesia is very rare. Anesthesia
specialists devote careful attention and use many methods to prevent this.
Risks from reactions to anesthetic medicines
Some anesthetic medicines may cause allergic or other abnormal reactions in some
people, but these are rare. If you suspect you may have such a problem, you should tell
both your surgeon and anesthesia specialist well before your surgery. Testing will then be
arranged as needed.
A rare, potentially fatal condition called malignant hyperthermia (MH) may be triggered
by some anesthetics. The anesthetics most commonly associated with malignant
hyperthermia include the potent inhalation anesthetics and the muscle relaxant
succinylcholine. For more information, see the listing for the Malignant Hyperthermia
Association of the United States (MHAUS) in the Other Places to Get Help section of
this topic." (WebMD, 2010).
"Although anesthesia is safer than in the past, complications do occur. One large study
showed that about 10 per cent of patients experienced some problem during or after
anesthesia. The complication could be as major as brain damage (but extremely rare) or
as minor as muscle soreness (but more common). The most frequent complications are
nausea, vomiting and sore throat. Anesthesiologists are trained to recognize and manage
complications quickly, and many will undergo part of this emergency training in
simulators, much like airline pilots do." (All About Anesthesia, 2011).
Sources:
All About Anesthesia. (2011). About anesthesia. Retrieved October 10, 2011, from
http://www.allaboutanesthesia.com/index.php?option=com_content&view=article&id=1
&Itemid=28
WebMD. (2010, January 28). Anesthesia risks and complications. Retrieved October 10,
2011, from http://www.webmd.com/pain-management/tc/anesthesia-risks-andcomplications