Do common local anesthetic mixtures crystallize in cerebrospinal fluid?

Crystallization of Local Anesthetic and Adjuvant Mixtures in Cerebrospinal Fluid as a Model for Interstitial Space - a Semiquantitative in Vitro Trial

Observational Medical University Innsbruck · NCT07442929

This project tests whether commonly used mixes of local anesthetics and adjuvants form crystals when added to spinal fluid taken from adults having lumbar puncture for normal pressure hydrocephalus.

Quick facts

Study typeObservational
Enrollment10 (estimated)
Ages18 Years and up
SexAll
SponsorMedical University Innsbruck Academic / other
Locations1 site (Innsbruck, Tyrol)
Trial IDNCT07442929 on ClinicalTrials.gov

What this trial studies

Leftover cerebrospinal fluid (CSF) from adults with normal pressure hydrocephalus undergoing elective lumbar puncture will be used ex vivo to test six commonly used local anesthetic (LA) and LA+adjuvant mixtures. For each mixture, a baseline grade of crystallization will be recorded without CSF and then mixtures will be combined with human CSF and observed immediately and every 15 minutes up to 60 minutes (t0–t3), with pH measured at each timepoint. Mixtures include combinations of ropivacaine, lidocaine, mepivacaine, chloroprocaine, sodium bicarbonate, and dexamethasone at ratios described in current literature. The study quantifies crystallization grade and pH changes to determine which combinations precipitate in human CSF under these conditions.

Who should consider this trial

Good fit: Adults with normal pressure hydrocephalus who are scheduled for an elective lumbar puncture and consent to use leftover CSF samples are eligible.

Not a fit: People under 18 years old or those not undergoing lumbar puncture would not be included and would not directly benefit from participation.

Why it matters

Potential benefit: If successful, the results could help clinicians avoid anesthetic combinations that are likely to precipitate in spinal fluid and inform safer drug mixing practices.

How similar studies have performed: Previous in vitro work has shown these mixtures can precipitate, but direct testing using human CSF is limited.

Eligibility criteria

Show full inclusion / exclusion criteria
Inclusion Criteria:

* Patients with normal pressure hydrocephalus scheduled for elective lumbar puncture.

Exclusion Criteria:

* Age \< 18 years

Where this trial is running

Innsbruck, Tyrol

Study contacts

How to participate

  1. Review the eligibility criteria above with your treating physician.
  2. Visit the official trial page on ClinicalTrials.gov for the most current contact information and recruitment status.
  3. Contact the listed study coordinator or principal investigator to request pre-screening. Pre-screening is free and never obligates you to enroll.
Conditions Hydrocephaluslocal anestheticslocal anesthetic mixturescerebrospinal fluidin vitrocrystallizationpHadjuvants
Last reviewed 2026-06-13 by the Find a Trial editorial team. Information on this page is for educational purposes and is not medical advice. Always consult qualified healthcare professionals about clinical trial participation.