Objective: To predict the infection and evaluate the severity of illness and prognosis for patients with infection of Pseudomonas aeruginosa (PA) in lower respiratory tract in intensive care unit (ICU) with the acute physiology and chronic health evaluation II (APACHE II).
Methods: The clinical data of 122 cases with infection of PA in lower respiratory tract were compared and studied. These data were evaluated with APACHE II score system according to Knaus method.
Results: APACHE II scores of the 29 nonsurvivors were significantly higher than that of 93 survivors (18.78+/-7.13 vs. 11.70+/-5.79, t=5.43, P<0.01). The patients with coinfections other than PA had a higher APACHE II score (14.76+/-6.89 vs. 10.08+/-6.14, P<0.01), a higher mortality (27.91 percent vs. 13.89 percent, P<0.01), and more days of stay in ICU [(28.47+/-23.59) days vs. (16.64+/-21.19) days] than those without. Patients with severe pneumonia had higher APACHE II scores (15.57+/-6.97 vs. 11.81+/-6.03) and poorer prognosis (39.22 percent vs. 12.68 percent) than those without. For all patients, when the APACHE II scores became higher and higher, the outcome became poorer and poorer, and the mortality higher and higher, and the percentage of severe pneumonia higher and higher. There was a significant correlation between APACHE II score and actual mortality (r=0.75, P<0.01) and predicted mortality (r=0.81, P<0.01). Actual and predicted mortality increased along with the increase in APACHE II scores by 5 scores. The sensitivity and positive rate of predicted mortality was 100.00 percent and 86.72 percent respectively.
Conclusion: APACHE II score system is highly valuable in predicting the infection and evaluating the severity of illness and prognosis in patients with infection of PA in lower respiratory tract in ICU.