Objective: To investigate the significance of first determined contents of procalcitonin (PCT), C-reactive protein (CRP), soluble triggering receptor expressed on myeloid cell-1 (sTREM-1) and the clinical pulmonary infection score (CPIS) in the detection of early-onset pneumonia (EOP) developed in patients suffering from stroke.
Methods: From June 2009 to June 2010, 244 stroke patients admitted to the emergency intensive care unit (EICU) in Shanghai Fifth People's Hospital were included in this prospective study. Patients were excluded if they were discharged or died in 24 hours of admission, or pneumonia was diagnosed at the admission. The serum levels of PCT, CRP and sTREM-1 were determined, and the CPIS was calculated in all patients on the day of admission.
Results: Among all 244 stroke patients, EOP was diagnosed in 105 of them, and 74 developed severe EOP. The serum levels of PCT, CRP, sTREM-1 and the CPIS in patients with EOP were significantly higher than those in patients who did not develop EOP [PCT (μg/L): 4.20 (0.83,7.75) vs. 0.19 (0.12,0.41); CRP (mg/L): 56.0 (18.5,105.5) vs. 9.0 (7.0,15.0) ; sTREM-1 (ng/L): 56.0 (24.5,111.5) vs. 10.0 (8.0,16.0); CRIS: 4.0 (2.5,4.0) vs. 2.0 (1.0,2.0), all P<0.01], and the levels of PCT, CRP, sTREM-1 and the CPIS in patients with severe EOP were significantly higher than those in patients with mild EOP [PCT (μg/L): 6.10 (3.40,8.83) vs. 0.61 (0.42,1.67); CRP (mg/L): 80.5 (31.5,113.0) vs. 21.0 (12.0,43.0); sTREM-1 (ng/L): 89.0 (53.8,132.8) vs. 21.0 (14.0,43.0); CPIS: 4.0 (3.0,5.0) vs. 2.0 (2.0,3.0), all P<0.01]. The cutoff point, sensitivity and specificity of each indicator to predict EOP were 89.5% and 79.1% in PCT>0.43 μg/L, 78.1% and 78.4% in CRP>16 mg/L, 81.9% and 84.9% in sTREM-1>19 ng/L, 75.2% and 79.9% in CPIS>2. Using PCT>0.43 μg/L combined with CPIS>3 to predict EOP, the sensitivity and specificity reached 81.9% and 92.1% respectively. The cutoff point, sensitivity and specificity of indicators to identify severe EOP were 87.8% and 83.9% in PCT>2.15 μg/L, 70.3% and 77.4% in CRP>43 mg/L, 81.1% and 90.3% in sTREM-1>51 ng/L, 67.6% and 83.9% in CPIS>3. Using PCT>2.15 μg/L combined with sTREM-1>56 ng/L to predict severe EOP, the sensitivity and specificity reached 82.4% and 100.0% respectively.
Conclusion: The first PCT is an effective indicator to predict EOP. The first CPIS is an index for screening EOP. PCT combined with CPIS may improve the specificity to predict EOP. The first sTREM-1 is a good indicator to identify severe EOP. Combination of first PCT and sTREM-1 may greatly improve the specificity to predict severe EOP.