the 1950s, anesthesia claimed about one life of every 2000 anesthetics given.
Particularly during the last 30 years, the frequency of anesthesia-related
complications leading to morbidity and mortality has decreased markedly, but
unfortunately not to zero. No one knows the actual incidence of preventable
anesthetic deaths; currently quoted numbers range from 1 in 20 000 to 1 in 200
000 anesthetics; a reasonable estimate probably lying somewhere in the middle
of these figures
risks are usually smaller than the risks associated with surgical
interventions, but they loom large when general anesthesia or heavy sedation is
required for a non-invasive and essentially risk-free diagnostic examination.
example, when a small child needs anesthesia to hold still for a CT scan or MRI
study, anesthesia poses the only risks.
drugs used in general anesthesia interfere with ventilation – think of
respiratory depression from narcotics, surgical anesthesia depressing reflexes
and relaxing the muscles of the upper airway and, worst of all, the commonly
used neuromuscular blocking agents, which spare the heart but paralyze the
muscles of respiration. Recognition of these potential respiratory problems has
led to the widespread use of endotracheal anesthesia, which requires the
insertion of a tube into the trachea, another potential for trouble. Tracheal
intubation is not always easy, and unrecognized esophageal intubation continues
to claim lives. No wonder then that inadequate ventilation and hypoxemia have
caused more grief than any other anesthetic complication. No organ depends more
on continuous perfusion with oxygen-carrying blood than the brain. The
consequences of brain hypoxia range from deterioration of intellectual function
also affect the cardiovascular system by weakening the myocardium, by
depressing autonomic control, and by a relaxing effect on smooth vascular
muscles. Decreased preload, low cardiac output, and hypotension result with
potential disastrous consequences.
anesthesia carries the risks associated with potential local anes-thetic
toxicity, resulting in hypotension or convulsions. In addition, the injec-tion
of drugs into a nerve plexus, a nerve, or into the epidural or subarachnoid
space, carries the risk of physical damage, bleeding, and infection. These
com-plications have been known to cause permanent neurologic changes and even
drugs are free of the potential for triggering an anaphylactic response, which
can be difficult to diagnose in a patient under general anesthesia. The
resulting severe hypotension and bronchospasm can then threaten the life of the
morbidity is not easily defined but is certainly more common than mortality.
Intra-operative hypotension and arrhythmias are common and, unless severe, are
not even mentioned as complications. Within hours after general anes-thesia,
25% of all patients may experience cognitive dysfunction; fewer suffer from
nausea and vomiting and/or sore throat, and even fewer have peripheral nerve
impairment, which usually resolves within weeks. Occasionally, we chip a tooth
during tracheal intubation, cause a hematoma with an i.v. catheter, or produce
more significant complications with invasive monitors, e.g., a pneumothorax
with a central catheter.
short, anesthesia does pose dangers. This raises the question of how to tell a
patient about potential complications in anesthesia or other procedures. Should
we pat the patient on the back and say, “Don’t worry, I’ll take care of you”?
Or should we enumerate all possible complications? What does the patient need
to understand, and what are we legally required to explain? The informed consent
process should result in the active participation of an autonomous and
competent patient choosing an anesthetic course based on the information and
compassionate medical advice. Physicians have been criticized either for being
overly paternalistic, or aloof and impersonal. Frequent complaints concern
fail-ure to explain findings and/or treatment plans. While it would be ideal
for each patient to understand the details of his or her medical care and
participate in all decisions, that level of true “informed consent” is
unattainable. Patients will almost invariably be cared for by several experts.
Even an expert physician in one field cannot fully appreciate the depth of
knowledge an expert in another field brings to the table; how much less then
can a medically na¨ıve patient hope to understand all ramifications of diagnosis,
prognosis, treatment options, and complications?
consent should fulfill both ethical and legal obligations in the
physician–patient relationship, including the pros and cons of the anesthetic
options and a description of complications with a 10% or greater risk of
occur-rence. In addition, rarer complications should be discussed if their
disclosure might affect the patient’s decision whether to proceed or seek
alternative therapy. Otherwise, it is ethically preferable and legally sound to
ask whether the patient wishes to hear about the less common but more serious
risks before presenting a comprehensive and dizzying list. For example,
enumerating risks of heart attack, stroke and death from anesthesia, need not
further upset a patient who is under-going a necessary operation. He already
knows he could die from the operation itself or from refusing surgery.
speaking with patients, before asking for their signature on a document
entitled “Informed consent,” we find ourselves confronted by a multi-horned
dilemma. We wish to explain our findings and therapeutic options, realizing
that the patient has a right to make decisions about his or her care. While we
do not wish to be paternalistic, we have the obligation to offer our opinion as
to the best treatment plan so that the patient has the benefit of our
knowledge. Sometimes, our opinion can be colored by our personal skills; when
two treatments are equiv-alent in all aspects, we should prefer the one with
which we have more experience. The legally required “informed consent” process,
therefore, calls for skillful and compassionate blending of information and
guidance covering (i) risks, com-plications and consequences of the proposed
treatment, (ii) alternatives, and (iii) conflicts of interest.