An observational study in Hydrocephalus, sponsored by Medical University Innsbruck. Completed at 1 site in Austria. Open to participants aged 18 Years and older. Per ClinicalTrials.gov, last updated 2026-08-25.
Sponsored by Medical University Innsbruck · Observational
Different mixtures of local anesthetics or local anesthetics with adjuvants that are known to precipitate in vitro are tested in human cerebrospinal fluid (CSF). CSF is gained from patients with normal pressure hydrocephalus scheduled for elective lumbar puncture. Patients signed an ICF for leftover samples.
CSF will be assessed for pH values at different timepoints (t0-t3; 0 to 60 minutes).
In a second step six commonly used mixtures of LA with LA or LAs with adjuvants will be mixed using the following mixture ratios: ropivacaine 0.75% + lidocaine 2% (ratio 1:1), ropivacaine 0,75% + mepivacaine 2% (ratio 1:1), ropivacaine 0.75% + chloroprocaine 2% (ratio 1:1), lidocaine 2% + sodium bicarbonate 8.4% (ratio 1:0.1), ropivacaine 0.75% + lidocaine 2% + sodium bicarbonate 8.4% (ratio 1:1:0.1) and ropivacaine 0.75% + dexamethasone (1.5:1). The used mixture ratios are inspired by commonly mixtures described in the current literature and have been proven to precipitate in vitro. For every mixture, a Grade of Crystallisation will be determined at baseline without CSF and then at t0 (immediately) to t3 (60 minutes) every 15 minutes.
Different mixtures of local anesthetics or local anesthetics with adjuvants that are known to precipitate in vitro are tested in human cerebrospinal fluid (CSF). CSF is gained from patients with normal pressure hydrocephalus scheduled for elective lumbar puncture. Patients signed an ICF for leftover samples.
CSF will be assessed for pH values at different timepoints (t0-t3; 0 to 60 minutes).
In a second step six commonly used mixtures of LA with LA or LAs with adjuvants will be mixed using the following mixture ratios: ropivacaine 0.75% + lidocaine 2% (ratio 1:1), ropivacaine 0,75% + mepivacaine 2% (ratio 1:1), ropivacaine 0.75% + chloroprocaine 2% (ratio 1:1), lidocaine 2% + sodium bicarbonate 8.4% (ratio 1:0.1), ropivacaine 0.75% + lidocaine 2% + sodium bicarbonate 8.4% (ratio 1:1:0.1) and ropivacaine 0.75% + dexamethasone (1.5:1). The used mixture ratios are inspired by commonly mixtures described in the current literature and have been proven to precipitate in vitro. For every mixture, a Grade of Crystallisation will be determined at baseline without CSF and then at t0 (immediately) to t3 (60 minutes) every 15 minutes.
210 studies on the registry are indexed under Hydrocephalus; 51 are open to participants now.
This study's enrollment of 2 is below the median of 60 across 98 observational studies indexed under Hydrocephalus.
Browse Hydrocephalus studies →Medical University Innsbruck is the lead sponsor of 182 studies on the registry; 49 are open to participants now.
Counted across the registry records on this site, refreshed daily.
patients with normal pressure hydrocephalus scheduled for elective lumbar puncture.
Exclusion Criteria:
Patients with normal pressure hydrocephalus scheduled for elective lumbar puncture
Grade of Crystallisation
For the grading of detectable precipitations, a scale from 0 (no signs of precipitation / single particulates \< 10 μm) to 5 (heavy polymorphic crystallization: \> 100 solid bodies \> 10 μm, and \> 1 solid body \> 50 μm or \> 1 solid body \> 100 μm) will be used.
Time frame: 1 hour
pH value and of CSF and CSF LA mixtures
pH value
Time frame: 1 hour
pCO2 of CSF and CSF LA mixtures
pCO2 in mmHg
Time frame: 1 hour
Plan to share: Yes — Data will only be shared on a reasonable request.
Supporting information: Analytic code
This study is completed, as verified in Sep 2025. You cannot join it, but the record below documents what was studied.
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Medical University Innsbruck