Cohort study of adult patients with complicated skin and soft-tissue infections

Abstract number: O301

Marwick C., Broomhall J., McCowan C., Gonzalez-McQuire S., Akhras K., Merchant S., Davey P.

Aim and Objectives: to describe the antibiotic treatment and outcomes stratified by severity in a representative sample of adult patients aged 18 or older who were treated in hospital for skin and soft tissue infections.

Background: Skin and soft tissue infection (SSTI) is one of the common indications for antimicrobial therapy in hospital. In the ESAC (European Surveillance of Antimicrobial Chemotherapy) point prevalence survey of 19 European hospitals in 2006 SSTI was the second most common infection after respiratory infection and accounted for 13% of all treatments. However, in comparison with respiratory infections there is little information about the outcomes of treatment for SSTI or about the validity of clinical severity scores.

Results: We identified 341 patients aged 18 or over in 2005 who had a new admission to Ninewells Hospital, Scotland between 1st January and 31st December 2005 and were discharged with one or more ICD10 codes for SSTI. There were 187 valid cases of SSTI. Microbiology samples (n = 480) were taken from 75% of patients. The most common isolates were Staphylococcus aureus (50% of positive cultures, of which 47% were MRSA) and Pseudomonas aeruginosa (17% of positive cultures). Death in hospital or within 30 days of treatment occurred in 19 (10%) patients. The patients received a total of 80 different empirical antimicrobial regimens. We stratified patients by Eron classification. We defined sepsis as presence of Systemic Inflammatory Response Syndrome (SIRS) and severe sepsis as a Standardised Early Warning Score >4. Two Infectious Diseases Physicians (CM and PD) independently judged empirical antimicrobial therapy as inadequate if it did not cover the most likely pathogens for any Eron Grade or if it was oral for Grades 2 to 4. Agreement between raters was 88%. Mortality and inadequate therapy both increased with Eron grade:

1No SIRS or co-morbidity: 45% patients, 4% mortality, 10% therapy inadequate.

2Significant co-morbidity but no SIRS: 33% patients, 7% mortality, 41% therapy inadequate.

3Sepsis, with SIRS: 17% of patients, 22% mortality, 40% therapy inadequate

4Severe sepsis: 5% of patients, 50% mortality, 100% therapy inadequate.

We also judged that 43% of patients received unnecessarily broad spectrum therapy.

Conclusions: SSTI is common and is associated with significant mortality. However, choice of empirical therapy is not evidence based, with significant under treatment of high risk patients.

Session Details

Date: 16/05/2009
Time: 00:00-00:00
Session name: 19th European Congress of Clinical Microbiology and Infectious Diseases
Location: Helsinki, Finland, 16 - 19 May 2009
Presentation type:
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