[The significance of clinical indicators of different Gram-stained bacteria resulted in secondary intracranial infection after craniocerebral operation].

Objective: To compare and analyze the clinical characteristics and laboratory parameters of central nervous system (CNS) infection caused by different Gram-stained bacteria after craniocerebral surgery, and to provide a preliminary basis for early anti-infection treatment to reduce the use of extended-spectrum antibiotics and the generation of resistant strains. Methods: A single center retrospective study was conducted to investigate the clinical data of patients with intracranial infection after craniocerebral surgery from January 2012 to December 2016 in PLA general hospital. The general conditions, clinical features, laboratory parameters, antibiotic treatments and prognosis were analyzed. Results: A toal of 813 cases of CNS infection after craniocerebral surgery were found during the 5-year period, with an incidence rate of 5.43% (813/14 986). The positive rate of cerebrospinal fluid (CSF)culture was 9.72% (79/813). According to the criteria, 71 cases were included in the study. Among all the cases, 64.8% (46/71) of which were Gram-positive bacteria (G(+) ) and 35.2% (25/71) were identified as Gram-negative bacteria (G(-)). The duration between surgery and meningitis events, as well as the period of antibiotic treatment for G(+) bacteria group were 5.0 (4.0, 6.0) days and (18.3±6.8) days, which were shorter than those of the G(-) bacteria group 9.0(7.0, 11.0) days and (29.2±9.9) days ( Z =-6.184, t =-5.245, both P <0.01) , and the differences were statistically significant. The serum procalcitonin concentration in the G(+) group was lower than that in G(-) group [1.02(0.83, 1.27)μg/L vs 2.68(1.97, 5.07)μg/L, Z =-5.719, P <0.01]. The cerebrospinal fluid glucose content was higher than that of G(-) bacteria group[(2.13±1.30) mmol/L vs (1.09±0.95) mmol/L, t =3.512, P <0.01]. The protein level was lower than that of G(-) bacteria group [(1 615.93±848.83) mg/L vs (2 480.60±1 105.28) mg/L, t =-3.679, P <0.01]. Serum C-reactive protein concentrations in the two groups did not show any statistical significance [(96.2±46.1) mg/L vs (117.8±46.3) mg/L, t =-1.884, P >0.05]. In addition, the mortality rate of the G(-) bacteria group was 16.0% (4/25), and 0 in G(+) bacteria group. Conclusion: The time of onset of intracranial infection, serum PCT concentration, and cerebrospinal fluid glucose and protein content caused by Gram-positive bacteria and Gram-negative bacteria are found to be significantly different, and these findings could serve as a preliminary guide for the selection of antibiotics in early experiential anti-infective treatments without the etiology report.