الفهرس 
Pathophysiology of AnaphylaxisOnly 14 pages are availabe for public view
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Abstract
Anaphylaxis is a potentially lethal reaction resulting
from the sudden, clinically significant release of mast celland/
or basophil-derived mediators into the circulation. Both
IgE-and non IgE-mediated mechanisms have been
implicated, and some agents may cause reactions by more
than one mechanism.
The most common identifiable causes of intraoperative
anaphylaxis are neuromuscular blocking agents (NMBAs),
antibiotics, latex, hypnotic induction agents (primarily
barbiturates), opioids, and colloids. However, there is a much
longer list of agents that are implicated less regularly
Risk factors include asthma, female sex (for certain
medications), other allergic conditions such as eczema or hay
fever, multiple past surgeries or procedures (especially for
latex), and mast cell disorders including mast cell activation
syndrome, monoclonal mast cell activation syndrome, and systemic mastocytosis.
Intraoperative anaphylaxis presents with cutaneous,
respiratory, and cardiovascular signs and symptoms, as well
as variable involvement of other organ systems. One-half of
cases are initially detected as sudden cardiovascular collapse.
Bronchospasm may present as an increase in the ventilatory pressure required to inflate the lungs or as a decrease in
arterial oxygen saturation.
Intraoperative anaphylaxis tends to be severe and has a
higher mortality rate than anaphylaxis occurring in other
settings. This is at least partly attributable to factors that
impair early recognition of anaphylaxis, such as the inability
of the patient to report initial symptoms and coverage of the
skin with surgical drapes. The intravenous administration of
drugs and concomitant stresses of surgery or illness may also
contribute.The diagnosis of intraoperative anaphylaxis is clinical.
An elevated serum total tryptase, plasma histamine level, or
elevated histamine or prostaglandin metabolites in the urine,
obtained at appropriate time intervals during and after the
reaction, are highly suggestive of anaphylaxis, although
normal levels do not exclude the diagnosis.
Documentation of anaphylaxis during anesthesia,
referral to an allergist for identification of the causative drug,
and appropriate labeling of the patient are essential to prevent
future episodes of anaphylaxis. Patient must be fully
informed about anaphylaxis, its cause, signs and symptoms
and causative agent. And he must be instructed to give
thorough history whenever he reports to any hospital for
treatment be it minor or major. He can be instructed to wear bracelet or carry card with him detailing which drugs he is
allergic to. What is needed is improved accuracy in
assessment of the rate of occurrence of anaphylaxis, and
rapid, specific, sensitive in vitro test or panel of tests to
confirm the clinical diagnosis of acute anaphylaxis.