The value of procalcitonin in diagnosis and treatment of neonatal ventilator associated pneumonia

Abstract

Objective To explore the value of procalcitonin (PCT) in diagnosis and treatment of neonatal ventilator associated pneumonia (VAP). Methods Sixty neonates needed invasive mechanical ventilation admitted to our NICU from Jan 2012 to Dec 2013 were divided into VAP group (30 cases) and non-VAP group (30 cases), depending on whether the neonates developed to VAP or not in 7 days. The VAP group then was randomly divided into PCT group (15 cases) and control group (15 cases) according to random number table. The levels of serum PCT, C-reactive protein (CRP) and WBC count were detected when the neonates suspected VAP before and after mechanical ventilation. Besides, the sensitivity, specificity, positive and negative predictive values for PCT, CRP and WBC were calculated in the diagnosis of VAP. Results The serum levels of PCT in VAP group had significant difference before and after mechanical ventilation (t=1.58, P=0.000), the levels of PCT were (0.37±0.25) μg/L and (2.17±1.46) μg/L respectively. The levels of PCT in non-VAP group had no significant difference (t=3.67, P=0.055). The levels of CRP and WBC showed no significant differences between VAP and non-VAP group before mechanical ventilation (P>0.05). Taking PCT≥0.40 μg/L, CRP≥28 mg/L and WBC≥10×109/L as the cut off value, the sensitivity of the three indicators diagnosis of VAP were 93.3%, 73.3% and 66.7% respectively. PCT had the highest sensitivity 93.3%, specificity 73.3%, positive predictive 77.8% and negative predictive 91.7%. The antibiotic duration of PCT group was (12.6±5.6) d compared with (15.1±9.1) d in control group (P=0.018). Conclusion Serum PCT has high sensitivity and specificity in the diagnosis of VAP, PCT combined with clinical pulmonary infection score can improve the diagnostic accuracy of VAP, early diagnosis and timely monitoring of serum PCT is helpful in VAP. PCT guidance substantially reduces antibiotic use in VAP, so that timely surveillance of PCT is necessary for patients on ventilator. Key words: Procalcitonin; Ventilator associated pneumonia; Clinical pulmonary infection score