Measurement of CSF opening pressure during lumbar puncture in the sitting position in the Emergency Department

Document Type


Publication Date



Academic Emergency Medicine


Volume 18, Supplement 1

Inclusive Pages



Background: Traditionally lumbar puncture (LP) is performed in the lateral decubitus position. For mechanical reasons, practicingphysicians may elect to perform the procedure with the patient in a sitting position. There are no data describing the normal range of cerebrospinal fluid (CSF) opening pressures (OP) inpatients in the sitting position.

Objectives: We sought to identify a range of normal CSF OP in the sitting-up, feet supported position (SUFS), and to determine whether head height above the needle affects the variance of the obtained pressures.

Methods: IRB-approved, prospective study of patients undergoing LP in two urban emergency departments (EDs). Exclusion criteria were < 18 years old, positive CSF findings, contraindication to LP, known hydrocephalus, structural intracranial abnormality, or ventricular shunt. Physicians performed LP in either the lateral decubitus (LD) or SUFS position, as per clinical judgment. CSF OP was measured in all patients. In SUFS patient, head height above needle hub (measured vertically to the level of the external auditory meatus) was obtained.

Results: Forty-two patients were included in the study (20 SUFS and 22 LD). There was no difference in age, height, or discharge rate in either group. There were more women in the LD groups (63% vs. 50%). The average OP was 14.8 cm higher in the SUFS position (19.8 cm LD vs 34.6 cm SUFS; p (SD) of OP pressures were similar (5.7 LD vs 5.9 SUFS) in the two groups. Average head height (HH) above the needle hub (SUFS only) was 28.5 cm (SD 7.9), and no correlation between HH and OP was found (R^2 = 0.06)

Conclusion: In the general ED population, opening pressure on patients in the SUFS position is significantly higher than opening pressure in the LD position, with a similar distribution. Variations in opening pressure cannot be explained by variations in HH above the needle hub. An alternative measure to determine the effects of the CSF column height on SUFS pressures should be sought.

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