Infectious Disease Flashcards
Definition of septic shock
Sepsis, plus dangerously low BP and abnormalities in cellular metabolism
Signs and symptoms of septic shock
Hypotension SBP <90mmHg
Signs of SIRS:
Signs of shock: hypoT, oliguria, lactic acidosis
Diagnostic workup of septic shock
+ Mangement:
essentially clinical dx
w/u: confirmed by blood cultures, often can’t find source of infection
Mangement: ABCs, O2, fluids, vasopressors (dopamine, NE, phenylephrine)
Acute menigococcemia onset timing?
Onset within hours to days
Neisseria meningitidis
Meningitis s/s?
fever, HA, n/v, photophobia, neck stiffness, AMS, purpuric rash, increased intracranial pressure.
Kernig: pain with knee flexion
Brudzinski’s: neck flexion causes involuntary flexion of hip/knee
Toxic shock syndrome
Eti:
S/s
S. aureus (also MRSA), group A strep
RFs: retained foreign bodies, tampons, skin and soft tissue infections etc.
S/s: Diffuse macular erythroderma, desquamation, hypotension, multiorgan involvement, fever.
Disseminated gonococcemia
Eti:
S/s
Dx
Neisseria gonorrhoeae
Eti: sexually transmitted.
S/s: Petechial or pusturlar acral skin lesions with erythematous base, asymmetric arthralgias, fever, general malaise
Dx: blood cultures
Nongonococcal acute bacterial (septic) arthritis Path: Eti: S/s: Dx:
Path: bacteria invade the joint space and release endotoxins and trigger cytokine release of neutrophil infiltation, leads to destruction of the joint
Eti: Staph a. , strep, gram - bact.
- Nongonococcal SA until proven otherwise!
S/s: Joint pain, fever, hx of joint swelling
Dx: Requires joint aspiration (gram stain and culture, crystal analysis
Gonococcal arthritis
Eti;
S/s
Eti: MC cause of septic arthritis in young sexually active people
S/s: Joint infection usually prodrome, often progress in additive pattern (knees, wrists, hands, ankles..)
- Fever, chills, rash
Dx: Cultures of mucous membranes
Viral arthritis
Path
S/s
Parvovirus B19, rubella, Hep B
s/s: symmetrical polyarticular arthritis
Lyme disease
Pathogen
S/s
borrelia burgdorferi
S/s: monoarticular or asymmetric joint involvement (usually large joints)
Dx: Serology IgM and IgG
Tx: Doxy 100mg BID 10-14 dyas
Osteomyelitis Eti S/s Dx Tx
- Contiguous (more common) open fracture, wound, etc
- Hematogenous, long bones in kids, spine in adults
- MC path: Staph A. 60%
S/s: fever, malaise, hot and painful joint
Dx: xray but MRI is better, ESR elevated, blood cultures
Tx: vanco + piptazo
Gas gangrene Eti S/s Dx Tx Abx empiric and definitive
ETi: clostridia (gram + rods)
S/s: Localized swelling with serosanguinous exudate soon after onset of pain
- Skin turns bronze, then blue/black with blebs and hemorrhagic bullae
- Crepitus
- Pain out of proportion
Dx: rapidly developing hemolytic anemia with elevated LDH, gram stain of exudate “box car” large gram + bacteria
Tx: Surgical debridment +
Empiric: Pip/tazo (zosyn)
Directed: PCN G and clinda
Indications to aspirate a potentially infected joint?
- febrile pt. with an acute flare of established arthritis to rule out superimposed septic arthritis
- unexplained inflammatory fluid
- monitor septic arthritis
Contraindications to doing joint aspiration
- needle aspiration through cellulitis or impetigo (absolute)
- coagulopathy or bactermia (relative)
Composition of typical synovial fluid? WBC %PMNs viscosity glucose
Normal WBC: <200cellmicroL
PMN: <25%
High viscosity
Glucose level similar to the pt’s serum
What would be seen on pseudogout joint aspiration?
Calcium pyrophasphate (CPP) crystals Phomboid shaped, positive birefringement (blue) crystals
Calcium phosphate crystals associate with what disease?
Osteoarthritis
- coffin lid shaped crystals, no birefringence
Calcium oxalate crystals associated with?
Renal disease on dialysis
- shaped like envelopes or pyramides
what situation do you see lower viscosity synovial fluid?
Associated with inflammatory issues
What would you expect to see out of a joint with gout?
Monosodiium urate crystals
- Needle shaped with negative birefringement (yellow)
SIRS criteria?
Temp <36 or >38
Heart rate >90
Respiratory rate >20
WBC >12,000
Cellulitis eti, types, s/s
Eti: Purulent : MRSA
Non purulent: B hemolytic strep…
S/s: skin tender and warm, erythematous, swollen. Edema and dimpling in the skin.
May have lymphangitis and lymphadenopathy.
Cellulitis risk factors:
Skin breakdown, leg edema, obesity, Immune-compromized, cirrhosis, lymphedema, venous insufficiency, CRF.
