Fever, Sepsis, Bacteremia

Question 1

Human body temperature is regulated by _____

​With fever, temperature ____ shifts upwards

Answer 1

the hypothalamus
•Like the ”thermostat” of the brain

“set point” shifts upwards

Question 2

Central temperature

Answer 2

Central(rectal) -about 0.5°C higher!
•Rectal temperature most closely estimates core temperature

Question 3

Adults > 65 have ____ average body temperatures

Answer 3

Adults > 65 have lower average body temperatures (and less likely to mount fever in response to infection)

Question 4

Fever induced by ____?___

Answer 4

pyrogenic cytokines leads to increased heat production (egshivering) or decreased heat loss (peripheral vasoconstriction)

Question 5

How is hyperthermia different from fever?

Answer 5

Hyperthermia is NOT cytokine mediated, “set point” of hypothalamus remains unchanged

•Occurs when environmental heat load or body metabolic heat production exceeds normal heat loss capacity

• Ex. Heat stroke, thyrotoxicosis, neuroleptic malignant syndrome
• Can be rapidly fatal if untreated

Question 6

Approach to fever –differential diagnosis

IMADE?

Answer 6

Infection –viral, bacterial, fungal
Malignancy –lymphoma
Autoimmune –SLE
Drugs –serotonin syndrome, neuroleptic malignant syndrome
Endocrinopathy –thyroid storm

Question 7

Important to know
What is the temporal pattern of illness?
Acute
Subacute
Chronic

Answer 7

• Acute viral infection, bacterial infection
• Subacute atypical infections, malignancy, autoimmune
• Chronic atypical infections, malignancy, autoimmune

Question 8

“Fever AND ______”

sore throat?

Answer 8

Viral URI, strep pharyngitis

Question 9

“Fever AND ______”

cough?

Answer 9

Cough: viral URI, pneumonia, flu, COVID

Question 10

“Fever AND _____”

rash

Answer 10

Cellulitis

Question 11

“Fever AND _____”

Dysuria

Answer 11

Dysuria:UTI, pyelonephritis

Question 12

Sepsis = can’t miss
What is it?

Answer 12

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

Key findings
•Hypotension
•Altered mental status
•Acute Kidney Injury
•Coagulopathy
•Increased respiratory rate

May or may not present with fever!

Question 13

Fever of Unknown Origin (FUO)

Definition?

Etiology?

Workup?

Answer 13

Definition: febrile illness (temperature of 101°F [38.3°C] or higher) for three weeks or longer without an etiology despite a one-week inpatient evaluation
•Notjust a new fever without an identified cause

• Etiology:•May be infection, autoimmune, malignancy (remember ”IMADE” mnemonic)
• Workup: •Complete history and physical•Extensive lab and imaging workup

Question 14

Low WBC count is a classic finding with _______

Answer 14

SLE

Question 15

Sepsis WBC? High/low?

Answer 15

Don’t be fooled –sepsiscan present with a high or low WBC count!

Question 16

Very high WBC count (ie>30,000) concerning for _________

Answer 16

leukemia/lymphoma

Question 17

Thrombocytopenia can be seen in sepsis, is due to _____

Answer 17

often due to disemminatedintravascular coagulation (DIC)

Question 18

Lactic acidosis

What is it?
What does it indicate?

Answer 18

Lactic acidosis = serum lactate concentration above 4 mmol/L

•Can be a marker of impaired tissue oxygenation due to tissue hypoperfusion!

Question 19

specificity helps with ruling (in/out) disease

Answer 19

In - SPIN

Question 20

sensitivity helps with ruling (in/out) disease

Answer 20

Out - SNOUT

Question 21

Blood culture - Presence of these organisms is always clinically significant (3):

Answer 21

• Staphylococcus aureus
• E. coli
• Pseudomonas aeruginosa

Question 22

Chest x-ray – Bacterial Pneumonia vs. COVID19 Pneumonia?

Answer 22

Bacterial Pneumonia•Focal infiltrate: can be suggestive of bacterial pneumonia

Typical findings with COVID-19:•Bilateral infiltrates•Basal and peripheral predominance

Question 23

Chest x-ray -SLE typical findings?

Answer 23

Pleural involvement and pleural inflammation in lupus is common (pleuritis)
•Can see pleural effusion on CXR

Question 24

Suspected CNS infection is a ______, what do you do?

Symptoms?

Answer 24

medical emergency and important indication for lumbar puncture

•Symptoms include fever, headache, meningismus

•Bacterial meningitis has a 14% to 25% mortality rate!
Thus rapid diagnosis and treatment = critical

Question 25

Antipyretics MOA?

Answer 25

Antipyretics work by reducing level of PGE2in the thermoregulatory center of hypothalamus

PGE2 production depends on enzyme cyclooxygenase (COX) acting on substrate of arachidonic acid

Antipyretics work by inhibiting COX thus preventing PGE2 from being produced

Question 26

Acetaminophen

action on peripheral tissues vs. brain?

Why preferred compared to NSAIDS?

when to use caution?

Answer 26

Poor COX inhibitor in peripheral tissues no significant anti-inflammatory effect

• Effective COX inhibitor in brain because acetaminophen oxidized by p450 system, and oxidized form inhibits COX
• Effective at reducing fever
• Preferred antipyretic, less renal toxicity compared to NSAIDs + no harmful effect on GI mucosa
• Use cautiously and at low doses with hepatic dysfunction

Question 27

NSAIDs - where are they effective?

AE?

Avoid in which patients?

Answer 27

• Inhibit COX peripherally and centrally
• Effective at reducing fever
• Adverse effect on platelets, GI mucosa; also has significant renal toxicity
• Avoid in patients with cirrhosis, CKD, CHF! Caution with CAD

Question 28

Aspirin MOA?

Avoid in what patients?

Answer 28

works by inhibiting COX

• Unique mechanism of action –irreversibly inhibits both COX-1 and COX-2
• Effective antipyretic
• Avoid aspirin in infants due to risk of Reye’s syndrome!

Question 29

When sepsis is suspected…

Answer 29

• Obtain basic labs including serum chemistries, blood count, cultures, imaging studies, lactic acid
• Fluid resuscitation EARLY in management with IV crystalloid
• Start antimicrobial therapy within 3 hours of presentation