Abstract

The role of serum procalcitonin in early diagnosis of lower respiratory tract bacterial infections is tested and studied. The prognosis of ventilator-associated pneumonia group and nonventilator-associated pneumonia group were compared. There was no significant difference between ventilator-associated pneumonia group and nonventilator-associated pneumonia group before mechanical ventilation. After mechanical ventilation, procalcitonin, C-reactive protein and white blood cells in ventilator-associated pneumonia group were significantly higher than those in nonventilator-associated pneumonia group (t=1.62-2.31, P<0.05) and the body temperature was also elevated, which is not significant. The sensitivity and specificity of procalcitonin in diagnosing ventilator-associated pneumonia were 86 and 91 %, respectively. Procalcitonin level in Gram negative bacteria group was significantly higher than that in Gram positive bacteria group (t=1.99, P<0.05). Immunofluorescence quantitative assay was used to detect respiratory infection patients and the treatment of some patients was monitored. At the same time, white blood cells and C-reactive protein were compared with procalcitonin. The sensitivity and specificity of procalcitonin in bacterial infections of respiratory system are obviously higher than those of traditional C-reactive protein and white blood cells. It can be used for early diagnosis of bacterial infections quickly. This study provided important clinical evidence in judging the severity and prognosis of infection and is helpful for rational use of antibiotics.