7: Fever

Question 1

Organ that regulates temperature

Answer 1

Hypothalamus

Question 2

When is body temp highest and lowest during the day?

Answer 2

Highest in afternoon, lowest in early AM

Question 3

How much higher is central temp (rectal) than peripheral temp (oral, TM, axillary)?

Answer 3

About 0.5 C higher

Question 4

Average body temp + definition of fever (according to Carl Wunderlich)

Answer 4

Average temp: 98.6

Fever: 100.4

Question 5

What can cause less of a fever response in patients?

Answer 5

1. Adults >65
2. Immunosuppression, corticosteroids
3. Several chronic diseases: CKD, hepatic dz

Question 6

Set point change in fever vs hyperthermia

Answer 6

Fever: set point increases and body temp rises to meet it
Hyperthermia: set point remains unchanged but body temp increases due to environmental heat or body metabolic heat increase

Question 7

Cytokines in fever vs hyperthermia

Answer 7

Fever: pyrogenic cytokines cause increased heat production or decreased heat loss
Hyperthermia: no pyrogenic cytokines involved

Question 8

Three examples of hyperthermia

Answer 8

1. Heat stroke
2. Thyrotoxicosis
3. Neuroleptic malignant syndrome

Question 9

Sepsis definition

Answer 9

Life-threatening organ dysfunction caused by dysregulated host response to infection

Question 10

Five key findings in Sepsis

Answer 10

1. Hypotension
2. AMS
3. AKI
4. Coagulopathy
5. Increased respirations
   (May or may not present with fever!)

Question 11

What can cause generalized LAD?

Answer 11

Systemic infection, autoimmune condition, malignancy like leukemia/lymphoma

Question 12

FUO: Fever of unknown origin

Answer 12

Febrile illness with temp of 101+ for 3+ weeks without an etiology despite 1wk inpatient evaluation

Question 13

Possible etiologies for FUO

Answer 13

Infection, autoimmune, malignancy, etc.

More common that its an atypical presentation of a common illness, but could be a typical presentation of a rare illness

Question 14

Normal range for WBC count

Answer 14

3,000 - 11,000 per mm3

Question 15

What autoimmune has classic low WBC count

Answer 15

SLE

Question 16

Normal platelet count

Answer 16

140,000 - 450,000

Question 17

Why does thrombocytopenia sometimes occur in sepsis?

Answer 17

DIC

Question 18

Four abnormal findings associated with sepsis from CMP

Answer 18

1. Increased BUN
2. Increased Cr
3. Anion gap acidosis
4. Liver function test abnormalities

Question 19

What does a serum lactate over 4 mmol/L mean?

Answer 19

Impaired tissue oxygenation due to tissue hypoperfusion

Question 20

Two values to look at in a urinalysis looking for infection

Answer 20

Leukocyte esterase + nitrites

Question 21

Specificity vs sensitivity

Answer 21

Specificity: helps rule things in
Sensitivity: helps rule things out

Question 22

Mechanism of antipyretics in reducing fever

Answer 22

1. COX acts on arachidonic acid -> produces PGE2

2. Antipyretics block COX -> decreases PGE2 -> less action on thermoregulatory center of hypothalamus

Question 23

Reason to treat fever

Answer 23

Manage sx like HA, myalgia, arthralgias

Question 24

Common organ system sources of infection in sepsis

Answer 24

Respiratory, GI, GU, skin/soft tissue

Question 25

Most common cause of sepsis

Answer 25

PNA

Question 26

Treatment for sepsis

Answer 26

1. Fluid resuscitation as soon as possible with IV crystalloid -> helps tx low BP
2. Antimicrobial therapy within 3 hours of presentation

Question 27

How to choose Abx for sepsis

Answer 27

1. Based on suspected infection site -> likely pathogen

2. Start broad and go narrow once culture data obtained