Objective:
To evaluate the diagnostic value of csf lactate (l(csf)) for the diagnosis of bacterial meningitis (bm) following neurosurgery, and compare it with other csf markers.
Methods:
Prospective study of consecutive neurosurgical postoperative patients admitted to the intensive care unit (icu) at maciel hospital. patients with clinical suspicion of bm were categorised, according to preset criteria, into 3 groups: (1) proven bm; (2) probable bm, and (3) excluded bm. csf markers were plotted in a receiver operating curve (roc) to evaluate their diagnostic accuracy.
Results:
The study included 158 patients. we obtained 46 csf samples from patients with clinical suspicion of bm by lumbar puncture (lp): 10 corresponded to proven bm, 4 to probable bm and 32 to excluded bm. mean lactate in csf (l(csf)) was: 10.72Β±4.68mm for proven bm, 6.07Β±0.66mm for probable bm and 3.06Β±1.11mm for excluded bm (p<.001 for proven bm and probable bm vs excluded bm; p=ns for proven bm vs probable bm). l(csf) displayed a better diagnostic accuracy for bm in the 2 scenarios studied: (1) positive bacterial csf culture or gram stain as positive control (gold standard) (sensitivity: 87%, specificity: 94%, cut-off value: 5.9mm), and (2) combination of proven bm and probable bm as positive control (sensitivity: 92%, specificity: 100%, cut-off value: 5.2mm).
Conclusions:
According to our results, determination of l(csf) is a quick, sensitive and specific test to identify the need for antimicrobial therapy in neurosurgical postoperative patients with clinical suspicion of bm.