8
Treatment
Pyomyositis
Î Magnetic resonance imaging (MRI) is the recommended imaging
modality for establishing the diagnosis of pyomyositis. Computed
tomography (CT) scan and ultrasound studies are also useful (SR-M).
Î Cultures of blood and abscess material should be obtained (SR-M).
Î Vancomycin is recommended for initial empiric therapy. An agent
active against enteric Gram-negative bacilli should be added for
infection in immunocompromised patients or after open trauma
to the muscles (SR-M).
Î Cefazolin or antistaphylococcal penicillin (eg, nafcillin or oxacillin) is
recommended for treatment of pyomyositis caused by MSSA (SR-M).
Î Early drainage of purulent material should be performed (SR-H).
Î Repeat imaging studies should be performed in patients with
persistent bacteremia to identify undrained foci of infection (SR-L).
Î Antibiotics should be administered intravenously initially, but once
the patient is clinically improved oral antibiotics are appropriate
for patients in whom bacteremia cleared promptly and there is no
evidence of endocarditis or metastatic abscess. Two to three weeks of
therapy is recommended (SR-L).
Clostridial Gas Gangrene or Myonecrosis
Î Urgent surgical exploration of the suspected gas gangrene site and
surgical debridement of involved tissue should be performed
(See Fig. 1/Nonpurulent/SEVERE) (SR-M).
Î In the absence of a definitive etiologic diagnosis, broad-spectrum
treatment with vancomycin plus either piperacillin/tazobactam,
ampicillin/sulbactam or a carbapenem antimicrobial is recommended
(SR-L). Definitive antimicrobial therapy with penicillin and clindamycin
is recommended for treatment of clostridial myonecrosis (SR-L).
Î Hyperbaric oxygen (HBO) therapy is NOT recommended because it has
not been proven as a benefit to patients and may delay resuscitation
and surgical debridement (SR-L).
