Primary endogenous pneumonia in severe burn patients

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

Objective

To determine primary endogenous pneumonia effect on severe burn patient mortality and to establish the associated factors with primary endogenous pneumonia.

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 primary endogenous pneumonia during the intensive care unit stay.

Statistical analysis

The variables potentially related to mortality were age, sex, total body surface burn area, full-thickness burn area, inhalation injury, primary endogenous pneumonia, bloodstream infection, burn wound infection and urinary tract infection. Comparison between groups was performed using Wilcoxon test or Fisher's exact test when appropriate.

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).

Fourteen patients developed 19 pneumonias: 12 primary endogenous, 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.

In the univariate and multivariate analysis the factors associated (P < 0.05) with mortality were primary endogenous pneumonia and full-thickness burn area. The risk factors associated (P < 0.05) with primary endogenous pneumonia were full-thickness burn area and inhalation injury. Increasing the number of cases (56 patients), both variables were statistically significant in the univariate analysis, but were not statistically significant in the multivariate analysis. At present we are continuing the study to know the factors associated with morbidity and mortality in severe burn patients.

Conclusion

Half the patients developed a pneumonia (63% primary endogenous pneumonia). The isolated pathogens were predominantly Staphylococus aureus. Primary endogenous pneumonia in severe burn patients may he associated with mortality, but is necessary collecting more cases to show it.