692
Chapter 19
Refl
ect and Review
#15
Where is the appendix located (see Figure 15–33)?
A bacterial infection of the membranes surrounding the ab-
dominal organs is found. This type of infection, called
peri-
tonitis,
results in
pus
(yellow liquid made up of white blood
cells, bacteria, and cellular debris) being produced. The pus is
removed, the abdominal organs are thoroughly washed with
saline and antibiotics, and the patient is returned to the ICU
where arterial and central venous blood pressures and urine
output are monitored.
Refl
ect and Review
#16
What is the purpose of monitoring central venous
blood pressure (see Figure 12–46)? Suggest other
variables to monitor in this patient.
In the hours after surgery, the patient is maintained on me-
chanical ventilation. Gurgling breath sounds and falling arte-
rial oxygen partial pressure indicate the presence of fl uid in his
lungs. Supplemental oxygen is provided to minimize the de-
crease in arterial oxygen by having the patient breathe a mix-
ture of air enriched in oxygen. Widespread swelling of body
tissues indicates that interstitial fl uid volume is increasing, and
his blood pressure and urine output remain dangerously below
normal. In addition to providing continued intravenous fl
uids
and antibiotic therapy, the ICU staff infuses norepinephrine
and vasopressin (vasoconstrictors), and methylprednisolone (a
synthetic glucocorticoid given at pharmacological doses). For
the next several days, the patient is critically ill while his condi-
tion is continuously monitored. Appropriate treatment adjust-
ments are implemented as needed to attempt to normalize his
blood volume, blood pressure, plasma lactate, plasma pH, and
gas partial pressures in his blood.
This patient’s condition began as acute
appendicitis,
but
the delay in treatment allowed it to progress to the potentially
lethal condition known as
septic shock.
Although
Escherichia
coli
and other bacterial species are normally present in the
large intestine and its associated appendix, blockage of the lu-
men of the appendix or the blood supply to the appendix can
allow those normally harmless bacteria to multiply out of con-
trol. When this happens, the appendix becomes distended and
the pressure inside the appendix increases signifi
cantly due to
infl ammation. Eventually, these factors can lead to ulceration
of the mucosa of the appendix, followed by rupture of the
organ. This releases bacteria into the peritoneal cavity. The
bacteria then release toxins that diffuse into the blood ves-
sels in the abdomen, leading to a dramatic cascade of events
(
Figure 19–5
). When a bacterial infection is accompanied
by a
systemic infl
ammatory response
(defi ned by symptoms
Figure 19–4
Normal abdominal CT scan (top) identifying major structures. CT
scan on the bottom shows an infl
amed appendix (arrow).
Figure 19–5
Cascade of some of the events from a serious infection to widespread
organ failure in septic shock.
Small bowel
(with contrast in lumen)
Cecum
Appendix
(normal)
Inflamed
Appendix
Descending
colon
Psoas
muscle
Aorta
Lumbar
vertebra
Inferior
vena cava
Lungs
Hyperventilation
Widespread tissues
An
a
erobic metabolism
Lactic (metabolic)
acidosis
Bone marrow
WBC production
Many organs
Ischemia +
malfunction
Vascular system
Blood pressure
Lungs and
other tissues
Fluid accumulation,
edema
Endothelial cells
Inflammation,
capillary leak
Heart
Contractility
Heart rate
Brain
Fever, decreased
appetite
Monocytes
and macrophages
Cytokine release
Bacterial toxins
in blood
Infection
(e.g., peritonitis)
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