infeccion necrotizante de tejidos blandos
TRANSCRIPT
-
7/28/2019 Infeccion Necrotizante de Tejidos Blandos
1/17
INFECCION NECROTIZANTE DE
TEJIDOS BLANDOS
-
7/28/2019 Infeccion Necrotizante de Tejidos Blandos
2/17
ANTECEDENTES
Jones 1871 and were termed hospital
gangrene.
In 1951,Wilson coined the term necrotizing
fasciitis.
infections of any of the layers within the soft
tissue compartment (dermis, subcutaneous
tissue, superficial fascia, deep fascia, or
muscle) that are associated with necrotizing
changes.
-
7/28/2019 Infeccion Necrotizante de Tejidos Blandos
3/17
ANTECEDENTES
incidence of NSTI in the United States is
estimated to be 5001500 cases per year.
0.04 cases per 1000 person-years.
Establishing the diagnosis of NSTI is probably
the greatest challenge in managing these
infections.
-
7/28/2019 Infeccion Necrotizante de Tejidos Blandos
4/17
DIAGNOSTICO
Delay of diagnosis leads to delayed surgical
debridement, which leads to higher mortality.
The first and most important tool for early
diagnosis of NSTI is to have a high index of
suspicion.
-
7/28/2019 Infeccion Necrotizante de Tejidos Blandos
5/17
FACTORES DE RIESGO
injection drug use
chronic debilitating comorbidities (e.g.,
diabetes mellitus, immune suppression, and
obesity).
most large published series
show that, in 20% of patients with NSTI, theetiology is unknown, and the patients are
considered to have idiopathic NSTI
-
7/28/2019 Infeccion Necrotizante de Tejidos Blandos
6/17
We have also observed that cases of NSTI
without a recognized precipitating factor are
more likely to be caused by group A
streptococcal and community-acquired
methicillin-resistant staphylococcal infection.
-
7/28/2019 Infeccion Necrotizante de Tejidos Blandos
7/17
Initial signs and symptoms swelling, erythema, pain,and tachycardia.
once the infection progresses: tense edema outsidethe area of compromised skin, pain disproportionate to
appearance, skin, discoloration (ecchymosis),blisters/bullae and necrosis, crepitus and/orsubcutaneous gas.
Systemic findings include: fever, tachycardia,hypotension, and shock (sensitivity is low, 1040%.
Progression of these signs and symptoms is usuallyrelatively fast, particularly if group A Streptococcus orClostridium species are involved.
-
7/28/2019 Infeccion Necrotizante de Tejidos Blandos
8/17
-
7/28/2019 Infeccion Necrotizante de Tejidos Blandos
9/17
Even in the most experienced hands, clinical
findings are not accurate enough for
diagnosis, and both clinical clues and
diagnostic tools should be used in
combination to help make an early diagnosis.
-
7/28/2019 Infeccion Necrotizante de Tejidos Blandos
10/17
PRUEBAS DE LABORATORIO
Wall et al. WBC count
115,400 cells/mm3 or a
serum sodium level 135
mmol/L was associated
with NSTI.
NPV of 99%, but not very
specific, PPV of only 26%.
Wong et al.
PPV of 92% and a NPV of
96%.
-
7/28/2019 Infeccion Necrotizante de Tejidos Blandos
11/17
ESTUDIOS DE IMAGEN
Radiography: identify subcutaneous gas
Ultrasonography: increased thickness of
the fascial layer with or without enhancement MRI
CT: deep abscesses
-
7/28/2019 Infeccion Necrotizante de Tejidos Blandos
12/17
OTROS METODOS
Biopsy specimen from the compromised site
that includes deep fascia and possibly muscle.
These findings include gray necrotic tissue,
lack of bleeding, thrombosed vessels,
dishwater pus, noncontracting muscle, and
a positive finger test result, which is
characterized by lack of resistance to fingerdissection in normally adherent tissues.
-
7/28/2019 Infeccion Necrotizante de Tejidos Blandos
13/17
MICROBIOLOGIA
A wide spectrum of
organisms are
commonly recovered.
2/3polymicrobial; 1/3Monomicrobial. gram-
positive cocci.
-
7/28/2019 Infeccion Necrotizante de Tejidos Blandos
14/17
TRATAMIENTO
source control, antimicrobial therapy, support,
and monitoring.
when treatment is only based on antimicrobial
therapy and support, mortality approaches
100%.
-
7/28/2019 Infeccion Necrotizante de Tejidos Blandos
15/17
TRATAMIENTO
Broad-spectrum antimicrobial therapy shouldbe started early to include coverage for gram-positive, gram-negative, and anaerobic
organisms. Special consideration for group A Streptococcus
and Clostridium species should be taken.
Acceptable regimens include monotherapyagents, such as imipenem, meropenem,ertapenem, piperacillin/tazobactam andtigecycline.
-
7/28/2019 Infeccion Necrotizante de Tejidos Blandos
16/17
TRATAMIENTO
Multidrug regimens have also been described,including triple-drug therapy regimens, suchas high-dose penicillin, high-dose clindamycin,
and a fluoroquinolone or an aminoglycosidefor coverage of gram-negative organisms.
Vancomycin, daptomycin, or linezolid shouldbe included in the regimen until methicillin-resistant staphylococcal infection has beenexcluded.
-
7/28/2019 Infeccion Necrotizante de Tejidos Blandos
17/17
MORTALIDAD
Since the first description by Jones [1], mortality
in patients with NSTI remains high. He reported a
mortality rate of 46%, and a recent pooled
analysis determined it to be34%. More recent series have reported mortality rates
with a range of 16%24%a rate that, although
lower than the rate 100 years ago, still accountsfor high mortality associated with NSTI