Infectious Disease Flashcards
Osteomyelitis and Septic Arthritis
Cellulitis and Abscess
Necrotizing Fascitis
Phlegmon
Diffuse cellulitis w/ WBC w/o a discrete focus
“Pre-abcess”
Septic Joint
Bacterial infection in the joint
Osteomyelitits
Infection of bone, joint, or cartilage
What is the difference between Cellulitis and Venous insufficiency?
- Cellulitis
- Acute
- Unilateral
- can cross Joints
- Acute
- Venous insufficiency
- Chronic
- Bilateral
- Doesn’t cross joints
- Limited to legs
- Looks infected but no fever or leukocytosis
What is the treatment for an abcess <2.5 cm? >4.5 cm?
<2.5 cm = Antibiotics
>4.5 cm = MUST be drained!!
Erysipela
- Characteristics
- Cause
- Characteristics:
- Form of cellulitis
- present on both sides of the face
- crosses the bridge of the nose
- Spares the globe of the eye
- Can move the eyes
- Cause:
- Strep pyogenes (Group A) >> S. agalactiae (Group B strep)
Who is most commonly affected by necrotizing fascitis?
Immune compromised patients
(Diabetics / Dialysis)
Necrotizing Fascitis
- Characteristics
- Method of progression of infection
- Characteristics
- Cellulitis dissecting along fascia
- Associated with diabetes and lack of blood flow
- Method of progression of infection
- Ascending toxin kills blood supply
What is Fornier’s gangrene?
Peri-genital Necrotizing Fascitis
What are the characteristics of each stage of wound?
- Stage 1
- Stage 2
- Stage 3
- Stage 4
- Stage 1
- Develop ischemia
- prolonged pressure = no blood flow
- No ulceration
- Develop ischemia
- Stage 2
- into skin
- Stage 3
- into subcutaneous tissue
- Stage 4
- into muscle
What is the function of biofilm? How do cells on the inside communicate with those on the outer borders?
- Function
- Increases resistance to Abtx
- Communicate by quorum sensing
What is the most common cause of Osteomyelitis?
Staph aureus
What is Wagner’s Classification for Diabetic Ulcers?
Time dependent vs Concentration dependent Killing (Antibiotics)
- Time dependent
- Effective due to extensive time bound to organism
- optimal response
- time drug remains above the MIC is equal or greater than 50% of the dosing interval
- Concentration dependent
- Effective due to high concentrations at the binding site
- Optimal Response
- Concentration is 10-20x MIC
Jane is a 55 yo WF who reports that she suddenly developed a rash on her face 24 hrs ago. She describes it as hot, red, tender and spreading around her nose onto both cheeks, but R>L side. Temperature is 101.2 and HR is 120. WBC is 13K.
•Which of the following statements is not true?
A)This is cellulitis
B)This is Erysipelas
C)It is most commonly caused by Group A Streptococcus
D)Necrotizing Fasciitis is a common complication
D
Elmer is a 63 yo diabetic postal worker who presents with a hot, red, swollen left knee that has progressively gotten worse over the past 2 weeks.
Which of the following statements is not true?
A)Staphylococcus aureus is the most common cause
B)Cartilage is destroyed by the toxins made by the bacteria
C)The blood flow in cartilage allows good drug delivery
D)If a prosthetic joint is present, then it is typically removed during the course of 6 weeks of IV antibiotics.
C
Sepsis and Endocarditis
What is SIRS?
Systemic Inflammatory Response Syndrome
- Vasodilation
- Leukocyte accumulation
- Increased vasc. permeability
- Non-infectious insult
- Uncontrolled pro - inflammatory release
What is Bacteremia?
Bacteria in the blood
What is Moderate Sepsis?
- End - organ dysfunction
- Correctible
- Lactate >2
What is severe Sepsis?
- 2 organ dysfunction
- Not correctible
- Lactate >4 mmol/L
***Need to pounded w/fluid (1L/hr)
What is septic shock?
- Same as above but with DIC
- At least one other organ dysfunction
- Persistent HypoTN despite fluid resuscitation
Treatment:
- Blood cultures before antibiotics
- Lactate before 90 minutes
- IV antibiotics before 180 minutes
- 3cc/kg of IV fluids before 180 minutes
What are the causes of endocarditis?
HACEK Group
- Haemophilus (NOT Influenza)
- Actinobacillus
- Cardiobacterium
- Eikenella
- Kingella
Sepsis can cause Endocarditis
Right Sided Endocarditis
- Causes
- IV Drug abuse
- Dialysis
- Signs
- “a new murmur is heard”
- Treatment is shorter than for L sided if due to IVDA
Risk of emboli to lungs
Left Sided Endocarditis
- Causes
- S. aureus
- HACEK
-
Dental source
- “patient had his teeth cleaned 2 mo ago” is a classic Q
- Symptoms
- Janeways lesions
- Osler’s nodes
- Splinter hemorrhages (nail bed)
- Treatment
- 6 wks
Stroke risk
45 yo male with history of DM, ESRD on Hemodialysis presents with 5 day history T 101.8, hypotension 88/62 despite 3 L NS, creat 5.8 (baseline 5.0), and HR 122. Lactate is 4.2
Which of the following is not true:
- This patient has severe sepsis
- Since he is stable, he does not need ICU care
- A cardiac echo is indicated to look for endocarditis
- If the dialysis catheter site looks OK, it can initially be left in place.
2
A 28 yo female presents to the ER with hx of fever 101, cough, weakness, myalgia, and rigors. Evaluation demonstrates WBC 14K, X ray with bilateral patchy infiltrates, HR 98, BP 110/68, and normal renal function. Lactate 2.5. Examination demonstrates a (new) 4/6 murmur present on the R 4th intercostal space. Needle tracts are found in the antecubital fossa bilaterally.
Pick the true statement
1.This is most consistent with L-sided endocarditis
2.This is most consistent with R-sided endocarditis
3.This murmur is most likely from the Aortic Valve
4.The HACEK group include Haemophilus influenza, Acinetobacter and Klebsiella
5.This patient meets criteria for the ICU.
●
2: right sided murmur
New murmur
Needle tracts
Meningitis
Meningitis vs Encephalitis
- Meningitis
- Headache
- Normal CNS function
- Encephalitis
- Altered mental status
- Motor/Sensory deficits
- Behavioral neurologic features
Meningitis Lumbar Puncture
- Elevated CSF
- Opening pressure often high
- Protein of 100-500 mg/dL
- Glucose <40 mf/dL
- Gram stain
Bacterial Meningitis causes
- Gp A strep
- Gp B strep
- Streptococcus pneumonia
- Haemophilus influenza
- Neisseria influenza
- MRSA
- Listeria
Viral Meningitis Causes
- Picornavirus
- HSV
- HIV
- West Nile Virus / Arbovirus
- Mumps
- Lymphocytic choriomeningitis virus
Neonatal HSV encephalitis is caused by which virus?
HSVII
Necrosis of temporal lobes is characteristic of what type of meningitis?
HSV
Labs in Mumps
- <500 wbc/uL Lymphocytes
- Protein slightly elevated or normal
- Glucose depressed
West Nile Encephalitis
- Symptoms
- Fever
- Back pain/myalgia
- Flaccid paralysis
- Seizures
- Nerve palsy
Fungal Meningitis
- Risk factors
- Causes
- Risk factors:
- HIV/AIDS
- Lymphoma
- Steroids
- Anti-TNF
- Diabetes
- Causes
- Aspergillus
- Zygomycetes
74 yo WF presents to the ER brought in by family with confusion with a history of 2 days of low grade temp, then spike to 102.4 today. Confusion started today, with bizarre behaviors and irritability. Non-compliant with exam, with episodes of lethargy. Possible meningismus. HR 102, BP 120/77. Labs are all normal.
LP reveals 440 WBC with 77% lymphocytes and 23% neutrophils and no organisms seen.
Which of the following is not true:
- CSF should be sent for HSV PCR
- This is Encephalitis
- MRI scan will likely show Temporal Lobe involvement
- This is Meningitis
4
Common lumbar puncture (LP) findings in bacterial meningitis include which of the following:
- WBC 400 with 77% neutrophils, glucose 34, Protein 200
- WBC 4, glucose 100, protein 64
- HSV PCR positive for HSV II
1 = meningitis
3 = encephalitis
_ STDS_