IMMUNOLOGIC DISORDERS/INFECTIOUS DISEASE

Question 1

What are the most common presenting symptoms of meningitis

Answer 1

Headache, fever, AMS, sensorial disturbances, neck and back stiffness, positive Kernig and Brudzinski signs, cerebrospinal fluid abnormalities

Question 2

Spinal fluid analysis of purulent meningitis (bacterial)

Answer 2

200-20,000 polymorphonuclear neutrophils, low glucose (<45), high protein (>50), opening pressure markedly elevated (norm is 70-180)

Question 3

Spinal fluid analysis of granulomatous meningitis (mycobacterial, fungal)

Answer 3

100-1000 mostly lymphoctyes, low glucose <45, high protein >50, opening pressure moderately elevated (norm is 70-180)

Question 4

Spinal fluid analysis of spirochetal meningitis

Answer 4

100-1000 mostly lymphoctyes, normal glucose (45-85), high protein >50, normal to slightly elevated opening pressure (norm 70-180)

Question 5

Spinal fluid analysis of aseptic meningitis, viral meningitis, or meningoencephalitis

Answer 5

25-2000 mostly lymphoctyes, normal or low glucose, high protein >50, slightly elevated opening pressure

Question 6

Spinal fluid analysis of “neighborhood reaction”

Answer 6

variably increased cells, normal glucose, normal or high protein, variable opening pressure

Question 7

purulent meningitis diagnosis

Answer 7

Gram positive smear (in 60-90% of cases) or gram positive culture (in 90% of cases) of cerebrospinal fluid

Question 8

chronic meningitis diagnosis

Answer 8

gram positive culture or serologic testing: cryptococcosis, coccidioidomycosis, syphilis, lyme disease

Question 9

Clinical manifestations of bacterial meningitis

Answer 9

fever, headache, neck stiffness, AMS, lethargy, nausea, vomiting, photophobia, seizures, coma, stupor, rash (petechial associated with meningococcal infection, purpura fulminans), myalgia, unilateral cranial nerve abnormality, papilledema, dilated nonreactive pupils, posturing, kernigs sign, brudzinski sign

Question 10

Management of bacterial meningitis

Answer 10

1. HandP, stat labs a 2 sets of blood cultures
2. Lumbar Puncture
3. Empiric therapy with IV antibiotics if: patient has purulent CSF at time of lumbar puncture, is asplenic, or has signs of DIC/sepsis pending gram stain and culture results

**don’t delay therapy if you can’t get culture

Question 11

Neonate (under 1 month old) empiric therapy for meningitis

Answer 11

Vanco plus gentamycin plus cefotaxime or cetfiraxone

Question 12

Meningitis empiric therapy for children (over 1 month old)

Answer 12

Vanco plus ceftriaxone or cefotaxime

Question 13

Meningitis empiric therapy for adults and those over 50 years old

Answer 13

Vanco plus ceftriaxone or cefotaxime

Over 50 add ampicillin to cover Listeria

Question 14

Meningitis empiric therapy for immunocompromised patients

Answer 14

Vanco plus ampicillin plus cefepime or meropenem to cover Pseudomonas

Question 15

Corticosteroid tx for meningitis

Answer 15

Dexamethasone 10 mg IV q 6h for 4 days

Question 16

Symptoms of bacterial endocarditis

Answer 16

Fever, Chills, Weakness, Dyspnea, Sweats, Anorexia, Weight loss, Malaise, Cough, Skin lesions, Stroke, N/V, Headache, Myalgia/arthralgia, Edema, Chest pain, Abd pain, Delirium/coma, Hemoptysis, Back pain

Question 17

Physical findings of bacterial endocarditis

Answer 17

Fever, Heart murmur, Changing murmur, New murmur, Embolic phenomenon, Skin manifestations, Osler nodes, Splinter hemorrhages, Petechiae, Janeway lesion, Splenomegaly, Septic complications (e.g. pneumonia, meningitis), Mycotic aneurysms, Clubbing, Retinal lesion, Signs of renal failure

Question 18

Empiric tx of bacterial endocarditis

Answer 18

Vancomycin 1G Q12H IV plus

Ceftriaxone 2G Q24H

Question 19

Antibiotic therapy for a patient diagnosed with uncomplicated pneumonia caused by S. pneumoniae

Answer 19

Uncomplicated cases caused by penicillin-susceptible strains may be treated on an outpatient basis with amoxicillin 750 mg BID x 7-10 days. PCN allergic alternatives are azithromycin; clarithromycin; doxycycline; levofloxacin; moxifloxacin

Question 20

Antibiotic therapy for a hospitalized patient diagnosed with pneumonia caused by S. pneumoniae

Answer 20

• PCN G 2 million IV Q4H or
• Ceftriaxone 1G IV Q24H (for strains that are not highly pcn-resistant) or
• Vancomycin (for those with serious PCN allergy or strain that is highly pcn-resistant) - alternatively the resp fluoroquinolone levofloxacin 750 mg

Question 21

Most common sites for nosocomial infections

Answer 21

• Urinary Tract Infections usually associated with Foley catheters or urologic procedures
• bloodstream infections, most commonly from indwelling catheters but also from secondary sites, such as surgical wounds, abscesses, pneumonia
• GU tract
• GI tract
• Pneumonia in intubated patients or those with altered level of consciousness
• surgical wound infections
• MRSA infections
• CDIFF

Question 22

Malarial prophylaxis when traveling to a country without drug-resistant parasites

Answer 22

• Bed nets treated with permethrin insecticides, indoor spraying of insecticides
• Chemoprophylaxis with chloroquine

Question 23

Management of Vancomycin-Resistant Enterococci (VRE)

Answer 23

-For rectal or stool colonization, therapy not recommended

-In symptomatic patient, If VRE strains are known to be susceptible, potential therapeutic agents include:
Linezolid
Daptomycin
Quinupristin-dalfopristin (Synercid)- only effective for E.Faecium strains

3 negative stool cultures obtained at weekly intervals to remove a pt from contact precautions

Question 24

Prevention of Vancomycin-Resistant Enterococci (VRE)

Answer 24

Hand Hygiene, contact isolation technique, and cleaning contaminated objects with standard hospital disinfectants

Question 25

Antibiotic management of pyelonephritis

Answer 25

- Ampicillin and an Aminoglycoside are initiated prior to obtaining sensitivity results - Can also use ceftriaxone, cipro, levofloxacin. Zosyn, meropenem or imipenem in toxic patients. - IV abx are continued for 24 hours after fever resolves, and oral anbx are then given to complete a 14 days course of therapy. - Follow up urine cultures are mandatory following completion of treatment

Question 26

What is osteomyelitis

Answer 26

Osteomyelitis is an acute or chronic infection of the bone secondary to the hematogenous or contiguous source of infection or direct traumatic inoculation, which is usually bacterial

Question 27

Essentials of diagnosis for osteomyelitis

Answer 27

- Fever and chills associated with pain and tenderness of involved bone. - Dx usually requires cx of bone bx. - ESR often extremely high (>100 mm/h) - Xrays early in the course are typically negative

Question 28

Clinical findings of Hematogenous Osteomyelitis

Answer 28

-resulting from bacteremia as a disease associated with sickle cell disease, injection drug users, diabetes mellitus, or older adults. -present with sudden onset of high fever, chills, and pain and tenderness of the involved bone. caused most often by salmonellae; S aureus is the second most common cause - Osteomyelitis in injection drug users develops most commonly in the spine. Although in this setting S aureus is most common, gram-negative infections, especially P aeruginosa and Serratia species, are also frequent pathogens. - Can lead to rapid progression to epidural abscess-fever, pain, and sensory/motor loss

Question 29

Older patient common sites of Hematogenous Osteomyelitis

Answer 29

thoracic & lumbar | Risk factors: DM, IV catheters, and urinary catheters

Question 30

Osteo from a contiguous focus of infection: source

Answer 30

- Prosthetic joint replacement, pressure injury (formerly called pressure ulcer), neurosurgery, and trauma most frequently cause soft tissue infections that can spread to bone. - S aureus and Staphylococcus epidermidis are the most common -Polymicrobial infections are common.

Question 31

Osteo from a contiguous focus of infection: signs and symptoms

Answer 31

- localized signs of inflammation are evident, but high fever and other signs of toxicity are usually absent. - Septic arthritis and cellulitis can also spread to bone.

Question 32

Osteomyelitis associated w/vascular insufficiency: who does it affect the most

Answer 32

DM pts w/ vascular insufficiency are susceptible to developing a very challenging form of osteomyelitis.

Question 33

Osteomyelitis associated w/vascular insufficiency: sites

Answer 33

- foot and ankle | - Originates from ulcer or other break down of skin (may appear disarmingly unimpressive)

Question 34

Osteomyelitis associated w/vascular insufficiency: signs and symptoms

Answer 34

- Absent or muted bone pain d/t neuropathy - Afebrile - **Two of the best bedside clues- ability to easily advance a sterile probe through a skin ulcer and a ulcer area larger than 2 cm.**

Question 35

Labs for osteomyelitis

Answer 35

- ↑ESR & CRP (can be useful parameters to follow during course of therapy) - Blood cultures

Question 36

Osteomyelitis xray

Answer 36

- est dx but can be falsely negative initially - Early xray- may include soft tissue swelling, loss of tissue planes, and periarticular demineralization of bone. - 2wks after onset of sx- erosion of bone and alteration of cancellous bone appear, followed by periostitis.

Question 37

Osteomyelitis MRI

Answer 37

most sensitive- demonstrates extent of soft tissue involvement

Question 38

Osteomyelitis CT

Answer 38

only do if pts has contraindication to MRI

Question 39

Osteomyelitis PET scan

Answer 39

high accuracy (similar to MRI) useful in pts with metallic implants

Question 40

Osteomyelitis Radionuclide bone scan

Answer 40

most valuable when osteo is suspected but no site is obvious. May also detect multifocal sites of infection

Question 41

Osteomyelitis ultrasound

Answer 41

dx effusions w/in joints and extra-articular soft tissue fluid collections but NOT in detecting bone infections.

Question 42

Osteomyelitis Bone marrow biopsy

Answer 42

- Identify organism=abx therapy (aerobic & anaerobic & fungi) - Is required EXCEPT in those with hematogenous osteo, who have +blood cx - Cultures from overlying ulcers, wounds, or fistulas are unreliable

Question 43

Treatment/management of osteomyelitis

Answer 43

- Debridement of necrotic bone and prolonged abx - Vertebral body and epidural abscess=urgent neurosurgical decompression - PO quinolones (ciprofloxacin) 6-8 wks; for S aureus= cipro + rifampin - Hyperbaric oxygen therapy- chronic osteo - Wound-assisted vacuum device-help would closure - Immobilization of affected bone (plaster, traction) if bone is unstable

Question 44

Challenges to treating osteomyelitis

Answer 44

Inadequate treatment of bone infections results in chronicity of infection, and this possibility is increased by delaying diagnosis and treatment. Extension to adjacent bone or joints may complicate acute osteomyelitis. Recurrence of bone infections often results in anemia of chronic disease, a markedly elevated ESR, weight loss, weakness and, rarely, amyloidosis or nephrotic syndrome. Pseudoepitheliomatous hyperplasia, squamous cell carcinoma, or fibrosarcoma may occasionally arise in persistently infected tissues.

Question 45

Antibiotic management of intra-abdominal infections

Answer 45

Zosyn, or ertapenem

Question 46

Aseptic Meningitis

Answer 46

-More benign and self-limited syndrome than purulent meningitis- is caused principally by viruses, especially herpes simplex virus and enterovirus group (coxsackieviruses and echoviruses) -Infectious mono may be accompanied by aseptic meningitis; leptospiral infection also in aseptic group -Also occurs during secondary syphilis and disseminated Lyme dz -Prior to MMR vaccine, mumps was most common cause of viral meningitis -Drug-induced aseptic meningitis reported w/ NSAIDS, sulfonamides, certain monoclonal antibodies