Crystallization of LA and Adjuvant Mixtures in Cerebrospinal Fluid

February 26, 2026 updated by: Medical University Innsbruck

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

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.

Study Overview

Status

Recruiting

Conditions

Detailed Description

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.

Study Type

Observational

Enrollment (Estimated)

10

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Contact Backup

Study Locations

  • Austria
    • Tyrol
      • Innsbruck, Tyrol, Austria, 6020
        • Recruiting
        • Medical University Innsbruck

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

  • Adult
  • Older Adult

Accepts Healthy Volunteers

No

Sampling Method

Non-Probability Sample

Study Population

patients with normal pressure hydrocephalus scheduled for elective lumbar puncture.

Description

Inclusion Criteria:

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

Exclusion Criteria:

  • Age < 18 years

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

Cohorts and Interventions

Group / Cohort
Patients with normal pressure hydrocephalus scheduled for elective lumbar puncture

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Grade of Crystallisation
Time Frame: 1 hour
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.
1 hour

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
pH value and of CSF and CSF LA mixtures
Time Frame: 1 hour
pH value
1 hour
pCO2 of CSF and CSF LA mixtures
Time Frame: 1 hour
pCO2 in mmHg
1 hour

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Medical University Innsbruck

Investigators

  • Principal Investigator: Elisabeth Gasteiger, MD PhD, Medical Unicersity Innsbruck

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General Publications

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

September 1, 2025

Primary Completion (Estimated)

September 1, 2026

Study Completion (Estimated)

September 1, 2026

Study Registration Dates

First Submitted

September 18, 2025

First Submitted That Met QC Criteria

February 26, 2026

First Posted (Actual)

March 2, 2026

Study Record Updates

Last Update Posted (Actual)

March 2, 2026

Last Update Submitted That Met QC Criteria

February 26, 2026

Last Verified

September 1, 2025

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • Crystal_Liquor

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

YES

IPD Plan Description

Data will only be shared on a reasonable request.

IPD Sharing Time Frame

Data will only be shared on a reasonable request.

IPD Sharing Access Criteria

Data will only be shared on a reasonable request.

IPD Sharing Supporting Information Type

  • ANALYTIC_CODE

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

Clinical Trials on Hydrocephalus

Search Similar Trials

Sponsors and Collaborators

Medical Conditions

Drug Interventions

CROs by country

CROs in Latvia

Conditions

Rare Diseases

Drug Interventions

Dietary Supplements

Sponsor/Collaborators

Locations

Subscribe