Determining the Value of Cerebrospinal Fluid Lactate Dehydrogenase Level in Differentiating Subarachnoid Hemorrhage From Traumatic Lumbar Puncture.

Context Lumbar puncture (LP) is still an important modality in the diagnosis of subarachnoid hemorrhage (SAH). Rapid and correct fluid analysis can provide patients with a better prognosis by appropriate intervention. Objective To determine the value of cerebrospinal fluid lactate dehydrogenase level in differentiation between SAH and traumatic LP. Design This was a cross-sectional observational study. Patients with a diagnostic suspicion of SAH who were admitted to the emergency department were enrolled in our study based on the inclusion criteria. All patients underwent head computed tomography scan without contrast. Patients with SAH confirmed on computed tomography scan and those who needed surgical intervention underwent LP by the neurosurgical service in the operation room (group 1). Other patients who fulfilled the inclusion criteria but had a traumatic LP in the emergency setting were also enrolled in our study (group 2). The fluid samples of all LPs were sent to the laboratory to be analyzed. Finally, we compared the results of the 2 groups with each other. Results Fifty-two patients were enrolled in our study, 26 patients (50%) from each group. The cerebrospinal fluid lactate dehydrogenase level was significantly higher in group 1 than it was in group 2 ( P < .001), and based on receiver operating characteristic curve analysis, the significant level of cerebrospinal fluid lactate dehydrogenase to differentiate SAH from traumatic LP was estimated to be 185. The red blood cell and white blood cell counts were significantly higher in group 1 than they were in group 2 ( P < .001). Conclusions Cerebrospinal fluid lactate dehydrogenase can effectively differentiate SAH from traumatic tap in LP samples.