Fatigue & Fever

Question 1

Metabolic/lab causes of fatigue (5)

(other than hypothyroid or anemia)

Answer 1

1. Electrolyte imbalances (Na, K, Ca, Mg)
2. Renal failure (GFR, Cr)
3. Liver dysfunction (AST/ALT, albumin)
4. B12/folate deficiency
5. Hyper- or hypoglycemia

Question 2

Common medications that cause fatigue (3)

(other than antidepressants/psychotics, anticonvulsants and benzos…)

Answer 2

1. Antihistamines
2. Beta-blockers
3. Chemotherapy agents

Question 3

Workup for unexplained fatigue in outpatient (6)

Answer 3

1. CBC
2. TSH
3. CMP/BMP
4. B12
5. Consider HIV, hepatitis panel, ESR/CRP if indicated
6. Depression/anxiety screen

Question 4

How can you differentiate chronic fatigue syndrome vs fibromyalgia?

Answer 4

• CFS: Fatigue >6 months, not relieved by rest, worsens with exertion
• Fibromyalgia: Widespread pain + fatigue + tender points + normal labs

Question 5

What is the core temperature cutoff for defining a fever in °C?

(>100.4°F)

Answer 5

> 38.0°C

Question 6

What are the top 3 non-infectious causes of fever in adults?

Answer 6

1. autoimmune disease (SLE, Still’s)
2. malignancy (lymphoma)
3. drug fever

Question 7

What defines a Fever of Unknown Origin (FUO)?

Answer 7

Fever >38.3°C for >3 weeks with no diagnosis after 3 days inpatient or 3 outpatient visits

Question 8

What is the empiric treatment for febrile neutropenia?

Answer 8

Immediate broad-spectrum IV antibiotics (e.g., cefepime)

(think: sepsis)

Question 9

What is “relative bradycardia” in fever, and what are 2 causes?

(aka “Faget Sign”)

Answer 9

• HR lower than expected for degree of fever
• Causes: typhoid, Legionella)

Question 10

What are the 5 W’s of post-op fever causes by post-op day?

Answer 10

1. Wind (atelectasis) POD 1
2. Water (UTI) POD 2-3
3. Wound (infection) POD 3-5
4. Walking (DVT) POD 5+
5. Wonder drugs (drug rxn)