Incidence and pathogenesis on severe burns patients infection

The study has been approved by the Institutional Board for Clinical Research

Objective

To know infection incidence, pathogenesis and microorganisms on severe burns patients.

Design

Prospective observational.

Setting

A six-bed burn intensive care unit.

Patients

All patients of ≥ 14 years admitted between January 1995 and January 1996 with a total body surface burn area of ≥ 20%. Exclusion criteria included immunosuppression, pregnancy and length of stay less than 5 days or admission ≥ 48 h following burn trauma.

Intervention

Collection of data on surveillance samples from throat and rectum on admission and afterwards twice weekly, and infections during the intensive care unit stay. The infections were diagnosed according to the CDC criteria.

Results

Thirty-one patients fulfilled the criteria of analysis. Mean age was 43 years (36–50), total body surface burn area 43% (36–50), full-thickness burn area 24% (17–31). Inhalation injury was identified on 13 patients. Mean stay was 28 days (21–35). Mortality was 29% (nine patients).

Twenty-two patients developed 59 infections: 28 primary endogenous, 27 secondary endogenous and four exogenous.

Fourteen patients developed 19 pneumonias: 12 primary endenous, six secondary endogenous and one exogenous. The causative microorganisms were: 14 Staphylococcus aureus, three Haemophilus influenzae, two Streptococcus pneumoniae one Pseudomona aeruginosa and one Acinetobacter spp. Eight patients had nine urinary tract infections: eight primary endogenous and one secondary endogenous. The pathogens were: six Escherichia coli, three Streptococcus faecalis and one Serratia.

Nine patients developed 10 burn wound infections: one primary endogenous, eight secondary endogenous and one exogenous. The causative microorganisms were: six Staphylococcus aureus three Pseudomona aeruginosa, one Escherichia coli, one Acinetobacter spp, one Proteus and one Klebsiella.

Fourteen patients had 21 bloodstream infections: seven primary endogenous, 12 secondary endogenous and two exogenous.The pathogens were: nine Staphylococcus aureus, four coagulase-negative staphylococcus, two Streptococcus faecalis, one Streptococcus faecium, three Escherichia coil, two Pseudmona aeruginosa, and one Candida spp.

Conclusion

Burns patients infections are similar to trauma patients, with 50% primary endogenous infections. The isolated pathogens were predominantly gram positive coccus, except in urinary tract infections.