Bacterial Diseases

Question 1

Modified Duke’s Criteria for Infective Endocarditis

Clue: BE FIVER

Answer 1

BE FIVER

■ Clinically defifinite case: 2 major, 1 major plus 3 minor, or 5 minor criteria
■ Clinically suspicious case: 1 major and 1 minor, or 3 minor criteria

MAJOR CRITERIA
1. Microbiologic
a. Two separate blood cultures positive for typical microorganism or
b. **Persistently positive blood culture **for typical microorganism
or
c. **Single positive blood culture for Coxiella burnetii **or a **Phase I immunoglobulin G antibody titer to C. burnetii ratio greater than 1:800
**
2. Evidence of endocardial involvement
a. New valvular regurgitation
or
b. Positive echocardiogram showing oscillating echogenic intracardiac mass at the site of endocardial injury, a periannular abscess, or new dehiscence of a prosthetic valve

MINOR CRITERIA
1. Predisposition (Risk factors) to infective endocarditis
2. Fever
3. Vascular phenomena such as Osler nodes or Roth spots
4. Immunologic factors such as a positive rheumatoid factor or glomerulonephritis
5. Serologic Evidence of active infection not meeting microbiologic major criteria

Question 2

Cutaneous signs of infective endocarditis

Clue: JOPS

Answer 2

Janeway lesions
Osler nodes
Petechiae/Purpura
Splinter hemorrhages

Cutaneous manifestations of IE, Sepsis, and DIC: splinter hemorrhages, Janeway lesions, Osler nodules, erythroderma, cellulitis, purpura, hemorrhage, purpura fulminans, and skin necrosis.

Question 3

Most concerning and severe complications of infective endocarditis

Answer 3

Neurologic in nature: nervous system complications (ischemic lesions), hemorrhagic strokes, transient ischemic attack, brain abscess, and meningitis

Question 4

The most common cause of infective endocarditis in high-income countries for both naïve and prosthetic valves.

Answer 4

Staphylococcus aureus

Question 5

Most common cause of right-sided infective endocarditis

Answer 5

IV drug usersright-sided infective endocarditis

right-side, tricuspid valve (recurring IE most often seen but has better

Question 6

Differentiate early and late prosthetic valve endocarditis

Answer 6

Early: first 2 months following valve replacement; most commonly caused by coagulase- negative streptococci or by S. aureus

Late: 2 months or later; caused by any of the infec- tious organism that can cause IE

Question 7

Poor prognostic indicators of infective endocarditis

Answer 7

left-sided IE, vegetation size (>10 mm), prosthetic valves, older age, diabetes, immunosuppression, heart failure, renal failure, septic shock, brain hemorrhage, and infections from methicillin-resistant S. aureus, fungi, or polymicrobial infections.

Question 8

Most common causes of death infective endocarditis

Answer 8

Cerebral embolic disease and congestive heart failure

Question 9

Settings in infective endocarditis that require surgery

Answer 9

Failure of parenteral antibiotic therapy, perivulvar abscess, valvular destruction/dysfunction with heart failure, persistent fever, and ischemic neurologic complications

Surgery should be avoided for 3 weeks if IE is complicated by hemorrhagi

Question 10

Differentiate Sepsis from Septic shock

Answer 10

Sepsis: life-threatening organ dysfunction that results from a dysregulated host response to infection.

Septic shock: a subset of sepsis in which vasopressor therapy is required to maintain a mean arterial pressure of 65 mm Hg or greater, and having a serum lactate level greater than 2 mmol/L persisting after fluid resuscitation

Question 11

SOFA Criteria

Cluee: GUBCPPP

Answer 11

Glasgow coma scale score
Urine output
Bilirubin
Creatinine
Platelet
Partial pressure arterial oxygen/fraction of inspired oxygen
mean arterial Pressure

SOFA scores (0-4) greater than 2 are suggestive of a 10% mortality risk

qSOFA (MRS): altered Mental status, Respiratory rate greater than 22 breaths/min, Systolic blood pressure less than 100 mm Hg

Question 12

Worse prognosis of sepsis

Answer 12

Hyperbilirubinemia (>1.2 mg/dL)
Renal insufficiency (creatinine >1.2 mg/dL)
Urine output (<500 mL)

Question 13

Strong and independent predictor of adverse outcomes in sepsis

Answer 13

Decreasing thrombocytopenia (below 150 × 109/L)

Serum lactate is not part of the SOFA criteria but can be a clinical out

Septic patient will generally have a WBC > 12 × 109/L or < 4 × 109/L, or a bandemia > 10%, and elevated CRP and procalcitonin levels.

Question 14

Most common cause of Disseminated Intravascular Coagulation (DIC)

Answer 14

Sepsis

Settings in which DIC can occur:
■ Hepatic failure
■ Immunologic reaction to drugs or toxins
■ Malignancy
■ Obstetrical complication (amniotic fluid embolism, placental abruption)
■ Protein C or protein S defificiency
■ Sepsis
■ Transfusion reactions
■ Transplant reaction
■ Trauma
■ Vascular abnormalities (aortic aneurysm, cardiac arrest)

Question 15

Waterhouse-Friderichsen

Clue: PACC

Answer 15

A syndrome of multiorgan failure characterized by a petechiae or purpura, coagulopathy, cardiovascular collapse, and bilateral adrenal hemorrhage.

Question 16

True or False

DIC is an independent predictor for organ failure and mortality.

Answer 16

True

DIC is an independent predictor for organ fail- ure and mortality. Patients with thrombocytopenia (<50 × 109/L) and DIC have a greater risk of bleeding. The mortality risk is doubled in patients with DIC who are septic or have experienced trauma.

Question 17

Routine laboratory testing in DIC is characterized by?

Increased and Decreased

Answer 17

Decreased platelet count (<100 × 109/L), protease inhibitors (protein C, protein S, antithrombin) and fibrinogen, ADAMTS13 (a disintegrin and metallopro- tease with a thrombospondin Type 1 motif member 13) activity
Prolonged prothrombin and activated partial thromboplastin time
Elevated fibrin degradation products (eg, D-dimer), PAI-1, van Willebrand factor, thrombomodulin, thrombin–antithrombin complex, and plasmin–plasmin inhibitor complex