VentWorld
Case Studies
Published July 16, 2001
William French and Christopher Joyce
Lakeland Community College, Kirtland, OH
www.lakeland.cc.oh.us/index.htm
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INTRODUCTION
SB, a 40-year-old female, was admitted to
the intensive care unit for shortness of breath, respiratory
failure, and sepsis. Past medical history medical history
was significant only for a splenectomy experienced in 1974
following a MVA. Recent history included cold and flu-like
symptoms for the past five days. Upon admission, she had inspiratory
crackles in the mid- and lower-lung fields, dry, non-productive
cough, and a temperature of 38.5 C.
CASE PRESENTATION
Examination revealed a female who is alert
and oriented, but extremely short of breath, with accessory
muscle use. SpO2 on a nasal cannula at 4 Lpm was 95%. Arterial
blood gases taken an hour after admission were as follows:
pH |
7.31 |
PaO2 |
98 |
PaCO2 |
24 |
SaO2 |
97% |
HCO3 |
12 |
base excess |
-15 |
The oxygen was increased to 6 Lpm, and the
patient was monitored over the next ninety minutes with no
improvement in shortness of breath. A second set of ABGs was
obtained:
pH |
7.26 |
PaO2 |
119 |
PaCO2 |
18 |
SaO2 |
98% |
HCO3 |
9 |
base excess |
-15 |
On the basis of the blood gas results and
the patient's clinical appearance, it was decided to intubate
her and place her mechanical ventilation via a Puritan-Bennett
7200 ventilator. The settings were:
Mode |
CMV |
Rate |
30 |
Tidal Volume |
450 mL |
Flow |
100 Lpm |
FiO2 |
50% |
PEEP |
+5 cmH2O |
The patient was assisting the ventilator
at 38 breaths per minute. Approximately one hour later, another
arterial blood gas sample was obtained:
pH |
7.26 |
PaO2 |
153 |
PaCO2 |
21 |
SaO2 |
97% |
HCO3 |
9 |
base excess |
-15 |
In response to these data, the FiO2 was decreased
to 35% and the patient was started on sodium bicarbonate via
IV.
Physical examination revealed coarse crackles
throughout both lung fields and sinus tachycardia. Chest radiograph
showed atelectasis of the left lower lobe with mild edema.
Analysis of ventilator pressures indicated an increased airway
resistance. Subsequent laboratory data revealed extreme leukocytosis
(WBC count 44,900), mild anemia (Hgb 9.8), renal failure,
and an increased anion gap. SB was started on four different
antibiotics, Lasix, and moderate sedation.
She was maintained on ventilatory support
for nine days until renal and liver function improved, sedation
was decreased, and she successfully weaned. ABGs taken post-extubation
were:
pH |
7.44 |
PaO2 |
87 |
PaCO2 |
34 |
SaO2 |
98% |
HCO3 |
23 |
base excess |
-2 |
FIO2 via NC |
2 Lpm |
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DISCUSSION:
Do you think the staff recognized and managed
the case appropriately? Post your thoughts or ask other questions
related to this case.
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