Abstract:

Objective To investigate the significance of serum procalcitonin（PCT） determination in the diagnosis and treatment of lower respiratory tract infection. Methods According to clinical symptoms,chest X-ray results and laboratory determination（sputum culture,serological detection,antigen detection and molecular biological detection） results,200 patients with lower respiratory tract infection were classified into bacterial infection,viral infection and mycoplasma and chlamydia infection groups,and their PCT levels were compared with those of 50 healthy subjects（healthy control group）. According to the voluntary principles,the bacterial infection group was sub-classified into control group and treatment group. Control group was treated according to antibiotics usage guidelines for regular treatment,and treatment group was treated with antibiotics by monitoring PCT levels. The antibiotic usage rates,antibiotic usage days,the length of inhospital,inhospitalization expenses,and so on were compared between the 2 groups. Results PCT levels in bacterial infection group and mycoplasma and chlamydia infection group were significantly higher than those in viral infection group and healthy control group（P<0.05）. PCT levels between bacterial infection group and mycoplasma and chlamydia infection group had statistical significance（P<0.05）,and those between viral infection group and healthy control group had no statistical significance（P>0.05）. PCT positive determination rates were 97.6% in bacterial infection group,17.1% in viral infection group and 17.9% in mycoplasma and chlamydia infection group. The antibiotic usage rates in treatment group and control group were 45.75% and 64.15%,respectively. The antibiotic usage days were 6.5±1.6 and（10.1±2.2）d. The lengths of inhospital were 9.4±2.8 and（12.8±4.5）d. Inhospitalization expenses were 5 862.5±98.6 and（7 420.5±115.4）CNY. The above statistics indices between the 2 groups had statistical significance（P<0.05）. Conclusions PCT determination can assist the clinical identification of lower respiratory tract infection,and monitoring PCT level can provide a reference for antibiotic usage in lower respiratory tract bacterial infection.

Key words: Procalcitonin, Lower respiratory tract infection, Antibiotics