ABSTRACT
Determine the variants of the cerebrospinal fluid in patients post-trauma and post-surgery without sepsis, to differentiate them from th variations in patients with meningitis. It's a prospective study in which we made lumbar puncture to 50 patients that were admitted in the neurosurgery service with the diagnosis of moderate or severe head trauma, or were operated for different reasons. All the patients had red blood cells in the cerebrospinal fluid. In 30 patientsthe white blood cells were >10 the relation of glucose in CSF/blood was less than 60 por ciento in 31 patients, and proteins were >45 mg/dl in 39 cases. Twenty-six patients had a relations red blood cell/white blood cell altered. All the cultures were negative. There was no correlation between fever, leukocytosis and number of white blood cells in CSF. Twelve patients had proteins elevated, glucose diminished and a low relation red blood cell/white blood cell. In all of them the culture was negative. Trauma and surgery procedure a subarachnoid hemorrhage that originates an inflamatory not infectious response, and this is the cause of the alterations of the cerebrospinal fluid. We recomended don't use antibiotics in post-trauma and post-surgery patients with fever and alterations of CSF, but without signs of meningitis, in wich the diagnosis in not confirmed with a culture of CSF