Objective: To establish baseline values of pneumonia
incidence and mortality and to distinguish primary endogenous from
secondary endogenous and exogenous pneumonias in a homogeneous patient
population with severe burns.
Setting: A six-bed burn ICU.
Patients: All patients of ≥ 14 years admitted to the ICU
between January 1995 and June 1996 with a total body surface area burn
of ≥ 20%.
Intervention: Collection of data on
surveillance samples from throat and rectum on admission and twice
weekly afterward, and pneumonias during the ICU stay.
Measurements and results: Fifty-six patients fulfilled the
criteria of the study. Mean age was 43 ± 19.8 years; total body
surface area burn, 41 ± 18.2%; the area of full-thickness burn was
24 ± 17.7%. Forty-one patients required mechanical ventilation.
Twenty-seven patients (48%) experienced 37 episodes of pneumonia.
Twenty-one pneumonias were of primary endogenous development,
ie, caused by potential pathogens carried in the
admission flora. There were 14 secondary endogenous and 2 exogenous
infections caused by microorganisms acquired on the burn unit.
Inhalation injury was identified in 26 patients. The pneumonia rate was
two times higher in the subset of patients with inhalation injury
compared with the group of patients without inhalation injury
(p < 0.001). Overall mortality was 25%.
Conclusions: This study shows that pneumonia in burn
patients is mainly an endogenous problem. Interventions that prevent
the development of endogenous infections deserve prospective evaluation
in patients with severe burns.