Cdiff/Osteomyelitis

Cdiff Organism and Pathophysiology

gram neg hardy spore-forming anaerobic rod

hand washing > hand sanitizer

gastric acid, bile acid, healthy flora keeps Cdiff in check

active infection produces toxins A and B that disrupt epithelial barrier and causes inflammation and pseudomembrane

Cdiff Risk Factors

age>65

hospital duration

antibiotics (carbapenems, ciprofloxacin, clindamycin, cephalosporins, etc)

IBD/CKD/ESRD

chemotherapy/immunosuppressants

GI surgery/manipulation/tube feeds

acid suppression (PPI)

complications/mortality risk factors- older age, leukocytosis, renal failure, comorbidities, etc

Cdiff S/S

non bloody watery diarrhea (>3/day), abdominal pain, leukocytosis, fever

complications toxic megacolon, rCDI, mortality

only test if s/s and confident Cdiff since part of normal flora (diagnostic stewardship), do not treat if no need to test

do not use antidiarrheals

Cdiff Classification

non severe

• WBC=<15k

• SCr =<1.5

• hemodynamically stable

severe (just one of following)

• WBC not 4-15k,

• SCr>1.5 or 50% increase

fulminant (just one of following)

• toxic megacolon

• ileus

• shock

Cdiff Dx Testing

NAAT high sensitivity tests for toxin gene

GDH high sensitivity tests for Cdiff prescence

toxin moderate specificity tests toxin A and B

1. GDH and toxin test (both positive or negative treat or do not treat)

2. If GDH positive but toxin negative do NAAT (treat if NAAT positive)

Cdiff Treatment Options

fidaxomicin- more specific, less dosing, reduces rCDI, $$ (no clinical difference in treatment)

vancomycin- must be PO because IV does not get to colon

metronidazole- ileus only

fecal microbiome transplant (FMT)

Cdiff Treatment Algorithm

initial Cdiff

• fidaxomicin 200mg BID PO x 10days

• alternative vancomycin 125mg QID PO x10 days

fulminant

• vancomycin 500mg QID PO and add IV metronidazole 500mg q8hr if ileus present, can also add rectal vanc

rCdiff

• try something new (standard vanc, pulsed vanc, standard fidaxomicin, eventually fecal microbiota transplant FMT)

long term suppression for patients who are not candidates for FMT, relapsed after FMT, or require ongoing frequent antibiotics

• oral vanc 125mg PO QD

Osteomyelitis Pathogens

S. aureus (main pathogen)

Salmonella (Sickle cell pts)

fungi (immunocompromised pts)

can cover empirically but culture for specific coverage

Osteomyelitis Types

hematogenous (through bloodstream)

• pediatric AHO

• NVO in older patients

  • worsening back/neck pain, fever, inflammatory markers, obtain blood cultures/aspiration biopsy before antibiotics unless sepsis or extremely ill

contiguous (adjacent soft tissue infection and vascular insufficiency)

• acute vs chronic with sequestrum less systemic signs but easier to visualize

  • dx DFO through Xray/MRI, inflammatory markers, and BeBoP, 3O not systemic 4O systemic

direct inoculation

DFO MRSA Risk Factors

hx of MRSA

antibiotic exposure

invasive procedures

open wounds

HIV infection

hospitalization/ICU

hemodialysis

DFO Pseudomonas Risk Factors

soacking feet

macerated ulcer

failed previous antibiotic therapy w/o coverage

severe infection

DFO Anaerobic risk factors

chronic foot ischemia leading to necrosis

DFO Patient Populations

adults cover S. auerus

PWID cover S. auerus and Pseudo

post-op/trauma/vascular insufficiency cover pos and neg

necrosis cover anaerobes

Antibiotics

MEMORIZE +/- TABLE and MONITORING TABLE

Duration of Therapy

usual course 4-6 wks, if completely debrided with margins after bone resection can do 3 wks

OPAT

IV at home, check for insurance, patient ability/comfort, electricity/refrigeration, and no concerns for misuse