L11 - Fever Examination And Investigation

Question 1

What is the definition of a fever?

Answer 1

100.4F

38C

Question 2

What is a fever?

Answer 2

A regulated rise to a new set point of body temperature in the hypothalamus
Induced by pyrogenic cytokines —> increased heat production (e.g. shivering) or decreased heat loss (peripheral vasoconstriction)

Question 3

What is hyperthermia?

Answer 3

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 4

Which organisms can cause a fever pattern of every other day?

Answer 4

P vivax and ovale (malaria)

Question 5

Which organism can cause a fever pattern of every 3rd day?

Answer 5

P malariae

Question 6

What can cause a stepwise fever pattern?

Answer 6

Typhoid fever

Question 7

What can cause a pel-Epstein pattern of fever (lasts 3-10 days followed by afebrile period of 3-10 days)?

Answer 7

Lymphoma

Question 8

What are the main causes of fever?

Answer 8

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

Question 9

What are some differential dx for a fever and sore throat?

Answer 9

Viral URI, step pharyngitis

Question 10

What are some DDx for a fever and cough?

Answer 10

Viral URI
Pneumonia
Flu
COVID

Question 11

What are some DDx for fever and a rash?

Answer 11

Cellulitis

Question 12

What are some DDx for fever and dysuria?

Answer 12

UTI

Pyelonephritis

Question 13

What is sepsis?

Answer 13

Life threatening organ dysfunction caused by dysregulated host responses to infection

Question 14

What are the key findings for sepsis?

Answer 14

Hypotension, altered mental status, acute kidney injury, coagulopathy and increased RR
May or may not present with fever

Question 15

What are the associated sx for SLE?

Answer 15

Malar rash, photosensitivity, oral ulcers, arthritis, hx of pleuritis or pericarditis, hx of seizures or other CNS disorders, hematuria, alopecia

Question 16

What are some commonly overlooked portions of the PE in pts with unexplained fever?

Answer 16

Dental (visible dental abscess/gum swelling? —> odonotogenic infection)
Female GU (vaginal discharge, cervical motion, tenderness? —> PID)
Bones/joints (hot red swollen joint, tender vertebral processes? —> septic arthritis, osteomyelitis)
Rectal (prostate severely tender to palpation? —> prostatitis)
Complete skin exam (abscess, cellulitis)

Question 17

Localized LAD can help you localize what?

Answer 17

An infection

Question 18

Generalized LAD can be a sign of what?

Answer 18

Systemic infection, autoimmune condition or malignancy

Question 19

What is a fever of unknown origin (FUO)?

Answer 19

Febrile illness (temp of 101F/38.3 or higher) for 3 weeks or longer without an etiology despite a one week inpatient evaluation 
Not just a new fever without an identified caused

Question 20

What is the etiology for a FUO?

Answer 20

May be infection, auto immune, malignancy (IMADE)

Atypical presentation of common illness&raquo_space; typical presentation of rare illness

Question 21

What is the work up for FUO?

Answer 21

Complete history and physical

Extensive lab and imaging work up

Question 22

What is on a CBC?

Answer 22

WBC, platelets, Hb, hematocrit

Question 23

What can cause leukocytosis?

Answer 23

DDx include stress, infection, malignancy, allergic reaction, medication effect (i.e. corticosteroids)

Question 24

What are some causes for leukopenia?

Answer 24

Wide differential including certain infections, malignancy, drugs, auto immune conditions
Low WBC count is a classic finding for SLE

Question 25

Sepsis can present with what?

Answer 25

A high or low WBC count

Question 26

When would monocytes be elevated?

Answer 26

Atypical infections (EBV, fungal, Protozoa, rickettsial, TB)

Question 27

What are infectious causes of thrombocytopenia?

Answer 27

Certain viral infections (EBV, CMV),hepatitis C, HIV, tick borne disease

Question 28

What are autoimmune causes of thrombocytopenia?

Answer 28

SLE

Question 29

What are malignant causes for thrombocytopenia?

Answer 29

Hematologic malignancies causing bone marrow failure or infiltration

Question 30

Thrombocytopenia can be seen in sepsis and is often due to what?

Answer 30

DIC

Question 31

What are CMP findings associated with sepsis?

Answer 31

Increased BUN and creatinine Anion gap acidosis (with low HCO3) Liver function test abnormalities can be a sign of multi organ dysfunction

Question 32

What is lactic acidosis?

Answer 32

Serum lactate concentration above 4mmol/L | Can be a marker of impaired tissue oxygenation due to tissue hypoperfusion

Question 33

Describe the leukocyte esterase test

Answer 33

High sensitivity, low specificity | Positive = pyuria, presence of WBCs in urine

Question 34

Describe the nitrite urine test

Answer 34

Low sensitivity, high specificity | Positive = presence of bacteria that reduce nitrate

Question 35

Specificity helps with what?

Answer 35

Ruling in a disease | SPIN

Question 36

Sensitivity helps with what?

Answer 36

Ruling out a disease | SNOUT

Question 37

Blood cultures are important to check if there are signs of what?

Answer 37

Sepsis/systemic infection Or concern for bacteremia Best to draw before giving abx (but do not delay abx to draw cultures)

Question 38

Presence of which organisms in a blood culture is always clinically significant?

Answer 38

Staph aureus E. coli Pseudomonas aeruginosa

Question 39

The presence of which organisms in a blood culture may be clinically significant but may also signify contamination?

Answer 39

Coagulate negative staph Corynebacterium species Enterococcus

Question 40

Describe molecular tests for COVID

Answer 40

``` PCR and NAAT tests Detection target = viral RNA Specimen types = nasopharyngeal, nasal, sputum and saliva Turnaround time = hours, days High sensitivity and specificity ```

Question 41

Describe antigen tests for COVID

Answer 41

``` Rapid tests Viral protein = detection target Specimen types = nasopharyngeal, nasal Turnaround time = minutes Low sensitivity, high specificity ```

Question 42

CXR is helpful in identifying what?

Answer 42

Pulmonary causes of fever | Including infectious, auto immune and malignant causes

Question 43

A focal infiltrate can be suggestive of what?

Answer 43

Bacterial pneumonia

Question 44

What are typical findings with COVID on a CXR?

Answer 44

Bilateral infiltrates | Basal and peripheral predominance

Question 45

What CXR findings are seen with SLE?

Answer 45

Pleural involvement and pleural inflammation (pleuritis) | Can see pleural effusion

Question 46

Suspected CNS infection is a medical emergency and important indication for what?

Answer 46

Lumbar puncture

Question 47

What are the symptoms of an CNS infection?

Answer 47

HA, fever, meningismus

Question 48

What does each tube test for during a lumbar puncture?

Answer 48

1. Chemistries (glucose and protein) 2. Cell count with diff 3. Gram stain and culture, other micro studies 4. Other studies as needed

Question 49

Describe bacterial meningitis

Answer 49

Deferential includes elevated neutrophils High opening pressure Low glucose Elevated protein levels

Question 50

Describe viral meningitis

Answer 50

Lymphocyte predominance Normal opening pressure Normal glucose and protein level