Case: Severe Fatigue and Dehydration:
Conrad Jackson is a 28-year-old man who presents to the emergency department with severe
fatigue and dehydration secondary to a 4-day history of vomiting. During the interview, he
describes attending a family reunion and states that perhaps he “ate something bad.” Upon
admission his vital signs are a temperature of 102.7°F, heart rate of 116 bpm, respiratory rate of 18
breaths/min, and blood pressure of 86/54 mm Hg. The nurse also notes the patient has dry mucous
membranes and tenting of skin. The physician orders an IV to be started with 0.45% normal saline,
and orders a serum electrolytes and an arterial blood gas. (Learning Objective 7)
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The following results are returned from the laboratory:
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Sodium (Na+)888888888888 150
Potassium (K+)8888888888 5.5
Chloride (Cl¯)888888888888 110
BUN88888888888888888888888888 42
Creatinine8888888888888888888 0.8
Glucose8888888888888888888888 86
pH888888888888888888888888888888 7.32
PaCO2888888888888888888888888 35
HCO3¯88888888888 88888888888 20
PaO2888888888888888888888888888 90
O28Sat8888888888888888888888888 98%
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Question of Case:
1. What is your interpretation of this arterial blood gas sample?
Explain the high potassium in this patient.
Calculate the patient’s anion gap:
What is the interpretation of this anion gap?
2. What is the most likely diagnosis for Conrad Jackson based on his
symptoms and laboratory results?
3. What are the potential causes of Conrad's severe fatigue, dehydration,
and vomiting?
