Atraumatic spinal needle indicates correct CSF opening pressure

The accurate assessment of cerebrospinal fluid opening pressure during spinal puncture provides important medical information in diagnosis, prognosis and therapy of several neurological conditions. However, purpose-specific spinal needle choice is debated. While atraumatic needles are associated with lower incidence of post-puncture headache and re-hospitalisation, some clinicians believe that they lack in accuracy of CSF opening pressure assessment. Our primary objective was to investigate different needle types on correctly assessing CSF opening pressure. We compared typical clinically utilised traumatic (0.9 mm outer diameter) and atraumatic (0.7 mm; 0.45 mm) spinal needles with regards to the assessment of the opening pressure in an experimental spinal puncture model testing experimental and cerebrospinal fluids in predefined pressures. Our goal was to measure the time until indicated pressure levels were correctly shown. Atraumatic needles of at least 0.7 mm diameter had a similar accuracy as traumatic needles without significant differences in time-to-equilibrium. These results were independent of protein and glucose concentration and the presence of haemoglobin. This study demonstrates that atraumatic needles can be used to accurately measure CSF opening pressure. This knowledge might guide clinicians in their choice of needle and help to reduce post-puncture headaches and re-hospitalisation.