Improved survival of burned patients with inhalation injury
L. W. Rue 3rd, W. G. Cioffi, A. D. Mason, W. F. McManus and B. A. Pruitt Jr
US Army Institute of Surgical Research, Ft Sam Houston, Tex.
OBJECTIVE: To study a cohort of patients treated at the same institution
and to compare that patient population with that of a previous report
documenting the comorbidity of inhalation injury and pneumonia.
Specifically, we wanted to determine whether there had been an improvement
in survival of patients suffering inhalation injury. DESIGN: A
retrospective review. SETTING: The US Army Institute of Surgical Research,
Ft Sam Houston, Tex, a 40-bed burn intensive care referral unit. SUBJECTS:
One thousand two hundred fifty-six thermally injured patients treated
between January 1985 and December 1990. MAIN OUTCOME MEASURE: A comparison
of pneumonia frequency and ultimate survival of the current cohort of
patients as compared with a previously generated stepwise logistic analysis
predicting mortality on the basis of 1980 to 1984 patient data. RESULTS: Of
1256 burned patients admitted between 1985 and 1990, there were 330
identified as having inhalation injury. These patients were older (35.0 vs
26.6 years) and had more extensive burns (41.1% vs 18.3%) and a higher
mortality (29.4% vs 5.0%) than did the patients without inhalation injury.
When compared with a mortality predictor generated from 1980 through 1984
patient data, patients in the most recent period had a lower mortality than
predicted (29.4% vs 41.4%). Patients with less severe injury (positive
xenon scan, negative results of bronchoscopy; n = 85), although having a
similar incidence of pneumonia (13.1% vs 19.5%) as the same group from 1980
through 1984, accounted for the most improvement in survival. The 3.6%
mortality was significantly less than the predicted rate of 15.7%. Patients
with positive results of bronchoscopy (n = 245) also showed some
improvement in outcome from that predicted (38.3% vs 50.2%) despite no
change in the rate of pneumonia (46.9% vs 48.5%). Further improvement in
survival was realized in those patients supported with high-frequency
ventilation. Although their age (33.9 vs 36.3 years), burn size (46.0% vs
45.5%), and duration of intubation (16.8 vs 15.1 days) were similar to
those of conventionally treated patients, mortality was significantly less
than predicted (16.4% vs 40.9%) and less than that in patients treated with
conventional ventilation (16.4% vs 42.7%). CONCLUSIONS: The improvement in
survival of patients with inhalation injury represents the aggregate
effects of the general improvement and outcome of all burned patients, the
prevention of pneumonia by high-frequency ventilation, and the reduced
mortality from the pneumonias that did occur.
