pressure. Using my ;ngers on the
pulse at her wrist, I could palpate her
systolic pressure. (;e top number in
any blood pressure reading, systolic
measures the maximum pressure of
the waves generated by the beating
heart.) Normal systolic pressure is
;;;. Below ;; is very low; less than ;;
and you’re in shock. Hers was ;;.
I immediately had my patient lie
down on the exam table to improve
circulation to her brain and rechecked
her blood pressure. It was still only ;;.
During prolonged shock, circulation
is inadequate to deliver oxygen to
your tissues for hours on end, and
multiple organs can shut down. It is a
life-threatening emergency. I told my
sta; to call ;;;.
;; ;;;; ;;;;; ;;; ;;;; ;; ;;;
patient was in anaphylactic shock,
a severe allergic reaction mediated
by the body’s immune system. Reactions to allergic triggers may be mild
or may rapidly progress to respiratory
or cardiovascular collapse and death.
Sometimes a reaction evolves over
hours. ;e allergic triggers are usually
food (especially nuts and shell;sh, but
also peppers), medications, or insect
stings. ;e symptoms typically involve
the skin (hives, ;ushing, itching)
and may also include the respiratory
system (wheezing with respiratory
failure) and the cardiovascular system (low blood pressure and shock).
When an anaphylactic reaction
hits, a ;ood of chemicals, primarily histamine, are dumped into the
bloodstream. Produced by specialized
blood cells that respond to injury,
infection, or allergic triggers, histamine is normally released locally in
tissues as part of the body’s defense
mechanism. But during anaphylaxis
this response goes haywire. When
large amounts of histamine pour into
the circulatory system, blood vessels
lose their elastic tone and get leaky.
Floppy, leaky blood vessels fail to
squeeze down when you are upright,
so blood pools in your extremities
instead of ;owing back to the heart.
H. Lee Kagan
is an internist in
Los Angeles. The
in Vital Signs
are real, but names
details have been
Cardiac output falls and blood pressure drops, leading to shock. ;at’s
why my patient fainted. In severe
reactions, patients may experience
shock even while lying down.
;e combination of tingling lips,
which can be part of an allergic
response, and dangerously low blood
pressure is what tipped me o; to the
anaphylaxis. It’s a diagnosis made
purely on clinical grounds; there is
no time to wait for con;rmatory
blood tests, since it can be fatal if
not treated promptly. Although there
are other causes of shock, if there is
any reasonable suspicion of anaphylaxis, it’s always better to treat ;rst
and ask questions later.
I shoved some pillows under my
patient’s legs to get them elevated,
hoping to increase blood return to
her heart and brain. I injected a dose
of epinephrine (adrenaline) from our
o;ce emergency kit into her thigh
muscle. Adrenaline quickly restores
tone to the blood vessels and ramps
up the strength and speed of cardiac action. Next I started an ;; and
;icked the control valve to wide open
so that saline would run into her vein
as quickly as possible and help restore
the volume of liquid circulating
through her arteries. My nurse placed
tubing under the patient’s nose to
maximize the amount of oxygen her
blood would deliver to her tissues.
By the time the paramedics had
her on their gurney ready to be transported to the ;;, my patient’s blood
pressure was up to ;;. Two hours
later, the ;; attending physician
called me to say that her pressure
was normal and she was doing ;ne.
Doctors planned to keep her there for
observation for the rest of the day to
be sure the reaction had blown over.
So was it the sweet peppers that
had started this nearly lethal chain
of events? Perhaps, but only allergy
testing could tell for sure. ;e patient
would need to see an allergist and
would also need to carry an emergency dose of injectable epinephrine
at all times in case of another reaction. In the meantime, the doctors
advised her to hold the peppers.