[The application value of the procalcitonin clearance rate on therapeutic effect and prognosis of ventilator associated pneumonia].
OBJECTIVE
To assess the disease severity and prognosis value by observing the kinetic change of serum procalcitonin (PCT) and PCT clearance rate (PCTc) in the patients with ventilator associated pneumonia (VAP).


METHODS
A single-center prospective observational study was conducted. A total of 128 patients with VAP admitted into intensive care unit (ICU) of First Affiliated Hospital of Xinjiang Medical University from February 2012 to June 2014 were enrolled. The patients were divided into recovery group (n=88) and deterioration group (n=40) according to the therapeutic outcome. The acute physiology and chronic health evaluation II (APACHEII) scores were estimated within 24 hours when VAP was diagnosed. The serum PCT (PCT1, PCT5, PCT7, PCT9) and PCTc (PCTc5, PCTc7, PCTc9) were examined at 1, 5, 7 and 9 days after the VAP was diagnosed. The diagnostic and predictive performance of PCT, PCTc and APACHEII scores were assessed by the receiver operating characteristic curve (ROC).


RESULTS
APACHEII scores in recovery group were significantly lower than those in the deterioration group (14.49 ± 5.30 vs. 18.90 ± 5.30, t=-4.349, P=0.000). There was no significant difference in PCT level (μg/L) at 1 day after VAP was diagnosed between recovery group and deterioration group [2.84 (0.81, 6.43) vs. 3.50 (0.97, 10.27), Z=-1.431, P=0.152]. With prolonged treatment, PCT was gradually decreased in recovery group, while remained at higher level in deterioration group, which was significantly lowered at 5 days after VAP diagnosed in recovery group compared with that in the deterioration group [1.28 (0.65,3.13) vs. 2.39 (0.78, 9.35), Z=-2.012, P=0.044]. PCTc maintained higher level in recovery group which was gradually increased with the improvement of the disease, and PCTc in deterioration group was lowered which was gradually decreased with the development of the disease. PCTc at 5, 7, 9 days in recovery group was significantly higher than that in deterioration group [5 d: 50.43 (20.39, 80.60)% vs. -56.68 (-286.28, 172.92)%, Z=-2.250, P = 0.024;7 d:54.01 (5.70, 102.30)% vs. -76.91(-335.03,181.21)%, Z=-2.561,P=0.010; 9 d:63.88(25.93, 101.80)% vs. -133.49(-547.20, 280.16)%, Z=-3.133,P=0.002]. The area under ROC curve (AUC) of PCT5, PCT7, PCT9 predicting the prognosis was 0.591, 0.683, 0.746, respectively [95% confidence interval (95% CI) was 0.456-0.726 (P=0.161), 0.557-0.808 (P=0.005), 0.631-0.860 (P=0.000)]. When PCT9 was 5.65 μg/L, the sensitivity of 95% and the specificity of 61%. The AUC of PCTc5, PCTc7 and PCTc9 was 0.648, 0.685, 0.729, respectively [95%CI was 0.513-0.783 (P=0.028), 0.555-0.815 (P=0.006), 0.607-0.851 (P=0.001)]. When PCTc9 was 92%, the sensitivity was 98% and the specificity was 71%. The AUC of APACHEII score was 0.693 (95% CI 0.578-0.808, P=0.003). When APACHEII score was 19.5, the sensitivity was 77% and the specificity was 58%.


CONCLUSIONS
The increased levels of PCT in patients with VAP were associated with the poor control of infection and may indicate the deterioration of VAP, it also can reflect the activity of lung infection in time. Keep observing the dynamic change of PCT and analyzing PCTc is more useful. The PCTc levels may provide evidence of disease progression and helpful in risk stratification in patients with VAP, and lower level of PCTc may accompany serious infection and predict poor prognosis.
Department of Critical Care Medicine, the First Affiliated Hospital of Xinjiang Medical University, Urumqi 830054, Xijiang, China, Corresponding author: Yu Xiangyou , Email:yu2796 @163.com.
Abudusalamu
A
Abula
Yi
Y
Wang
Long
L
Ma
Xiangyou
X
Yu
D018806:APACHE; D002116:Calcitonin / Q000378:metabolism*; D015740:Calcitonin Gene-Related Peptide; D006801:Humans; D007362:Intensive Care Units; D053717:Pneumonia, Ventilator-Associated / Q000378:metabolism / Q000628:therapy*; D011237:Predictive Value of Tests; D011379:Prognosis; D011446:Prospective Studies; D011498:Protein Precursors / Q000378:metabolism*; D016896:Treatment Outcome
C000606589:CALCA protein, human; D011498:Protein Precursors; D002116:Calcitonin; D015740:Calcitonin Gene-Related Peptide