[The prognostic value of serum procalcitonin on severity of illness in non-sepsis critically ill patients].

OBJECTIVE

To evaluate the correlation between serum procalcitonin (PCT) level and severity of diseases caused by different kinds of stress factors, and to identify the prognostic value of PCT on the prognosis in non-sepsis critically ill patients.

METHODS

A retrospective case control study was conducted. The clinical data of non-sepsis critically ill patients with age of ≥ 18 years admitted to surgery intensive care unit (ICU) of China-Japan Friendship Hospital from August 2013 to December 2015 and stayed for more than 3 days were enrolled. The PCT level in the first 24 hours, acute physiology and chronic health evaluation II (APACHE II) score, sequential organ failure assessment (SOFA) score and 28-day mortality were recorded. Patients were divided into different groups by the original injury, including trauma stress group, stroke stress group and non-infection inflammation stress group. According to PCT level, patients were divided into PCT normal group, low level group, medium level group and high level group. Furthermore, patients were divided into survival group and non-survival group according to 28-day prognosis. The clinical data of patients were compared among the groups, and the correlations among different markers were analyzed with Pearson or Spearman correlation analysis. The predictive value of PCT on prognosis of non-sepsis critically ill patients was evaluated with receiver operating characteristic curve (ROC).

RESULTS

Ninety-four non-sepsis critical ill patients were enrolled, with 28 patients in trauma stress group, 30 in stroke stress group, and 36 in non-infection inflammation stress group, as well as 32 patients in PCT normal group, 18 in low level group, 18 in medium level group, and 26 in high level group. Of them, 78 survivors and 16 non-survivors were found. (1) The PCT level of non-sepsis critically ill patients was significantly positively correlated with APACHE II score and SOFA score (r1 = 0.688, r2 = 0.771, both P = 0.000). (2) The PCT level in trauma stress group was significantly higher than that in stroke stress group and non-infection inflammation stress group [μg/L: 4.43 (0.86, 11.72 ) vs. 0.28 (0.16, 5.85), 2.39 (0.13, 4.11), both P < 0.01]. APACHE II score (13.9±7.5, 13.9±7.0 vs. 9.4±4.4), SOFA score [7.0 (4.0, 9.0), 5.0 (3.0, 8.0) vs. 4.0 (2.0, 6.0)], and 28-day mortality [21.4% (6/28), 33.3% (10/30) vs. 0 (0/36)] in trauma stress group and stroke stress group were significantly higher than those of non-infection inflammation stress group (all P < 0.05). The abnormal rate of PCT in trauma stress group was significantly higher than that of stroke stress group and non-infection inflammation stress group [100.0% (28/28) vs. 33.3% (10/30), 66.7% (24/36), both P < 0.01]. (3) Non-survivors had significantly higher PCT level [μg/L: 6.02 (4.43, 18.34) vs. 0.76 (0.16, 4.11)], APACHE II score (22.5±3.8 vs. 10.1±5.1) and SOFA score [9.0 (7.0, 11.0) vs. 4.0 (2.0, 8.0)] as compared with those of survivors (all P < 0.01). (4) APACHE II score (7.8±2.8, 9.3±4.3, 13.7±6.2, 18.7±5.8, F = 22.495, P = 0.000), SOFA score [3.0 (1.2, 4.8), 4.0 (3.5, 4.5), 6.0 (3.5, 8.0), 10.0 (8.8, 12.0), Z = 51.040, P = 0.000], and 28-day mortality [0 (0/32), 11.1% (2/18), 22.2% (4/18), 38.5% (10/26), χ (2) = 15.816, P = 0.001] were gradually increased as PCT level elevated. (5) The area under ROC curve (AUC) of PCT for evaluating prognosis of non-sepsis critically ill patients was 0.799 [95% confidence interval (95%CI) = 0.709-0.889, P = 0.000], when the cut-off value was 4.2 μg/L, the sensitivity was 87.5%, and the specificity was 77.6%.

CONCLUSIONS

Serum PCT level was positively correlated with severity of illness in non-sepsis critically ill patients, which had predicted value on prognosis. Trauma stress can lead to higher PCT level than stroke stress and non-infection inflammation stress can.