Combined diagnosis of CNS infections in the post-surgical setting.

Introduction: Central nervous system (CNS) infections following neurosurgical interventions represented a serious, although infrequent, complication. Despite their low incidence, they generated high morbidity and mortality. These infections included meningitis, ventriculitis or brain abscesses, with factors such as the type of procedure and antibiotic prophylaxis being determining factors in their occurrence. Against this background, cerebrospinal fluid (CSF) analysis played a key role in the initial diagnosis.Development:The physicochemical analysis of CSF made it possible to identify alterations suggestive of infection through parameters such as glucose, proteins, pleocytosis and lactate. However, in patients who had received antibiotic treatment, these values were modified, making diagnosis difficult with conventional methods such as cultures and Gram staining. To overcome these limitations, molecular technologies such as multiplex PCR were introduced, which offered greater sensitivity and made it possible to detect specific pathogens such as Neisseria meningitidis or Streptococcus pneumoniae in less time. However, these tests also presented risks, such as false positives, requiring careful clinical interpretation.Conclusions: CSF physicochemical analysis continued to be useful, but insufficient as the only diagnostic tool. Combination with molecular methods increased the accuracy and speed of diagnosis, allowing more timely treatment. Consequently, it was concluded that the most effective approach was integrated diagnosis, which combined traditional techniques with molecular testing within an appropriate clinical framework.