SIMULTANEOUS LUMBAR AND INTRAVENTRICULAR MANOMETRY TO EVALUATE THE ROLE AND SAFETY OF LUMBAR PUNCTURE IN RAISED INTRACRANIAL-PRESSURE FOLLOWING SUBARACHNOID HEMORRHAGE

We report a prospective investigation of a bedside test to evaluate th e role and safety of lumbar puncture in raised intracranial pressure i n patients with subarachnoid haemorrhage. Fourteen patients who underw ent aneurysm clipping following subarachnoid haemorrhage were studied. All patients had intraventricular drains and needed high volume cereb rospinal fluid (CSF) drainage to maintain the normal intracranial pres sure. A lumbar puncture was performed in these patients and the simult aneous opening lumbar and ventricular pressures noted, CSF was then dr ained via the lumbar puncture, and the simultaneous closing lumbar and ventricular pressures noted. In all patients, the opening lumbar pres sure was close to the ventricular pressure. In 13 of 14 patients, CSF drainage resulted in an equivalent and simultaneous fall of Ventricula r pressure. We conclude that simultaneous measurement of lumbar and ve ntricular CSF pressure before and after lumbar CSF drainage allows ide ntification of candidates with differential cranial and lumbar pressur es and therefore indicates safety or risk of lumbar CSF drainage.