The 50:50 Nitrous Oxide vs 2% Lidocaine Challenge

NCT07618676 | Recruiting

• 1 other identifier: 01-1/2025/1264
• Study Type: interventional
• Target: 62
• Locations: 1 country
• Sites: 1

Brief Summary

The main goal of the project is to assess pain levels and patient comfort during the administration of a 50:50 Nitrous Oxide/Oxygen gas mixture, in comparison to the same parameters under the standard method used at our institution, which includes injecting a local anaesthetic at the site of planned puncture for central venous catheterisation.

Conditions

Acute Pain; Anxiety; Central Venous Catheter

Outcome Measures

Primary Outcomes (3)

• Pain Intensity During Needle Insertion

  Assessed using a standard Numeric Rating Scale (NRS) ranging from 0 (no pain) to 10 (worst imaginable pain). Higher scores indicate greater pain intensity.

  At the time of needle insertion

• Pain Intensity During Catheter Placement

  Assessed using a standard Numeric Rating Scale (NRS) ranging from 0 (no pain) to 10 (worst imaginable pain). Higher scores indicate greater pain intensity.

  During catheter placement

• Pain Intensity Post-Intervention

  Assessed using a standard Numeric Rating Scale (NRS) ranging from 0 (no pain) to 10 (worst imaginable pain). Higher scores indicate greater pain intensity.

  2 minutes after gas inhalation (Treatment 1) or 2 minutes post-intervention (Treatment 2)

Secondary Outcomes (3)

• Patient Anxiety Score

  Post-intervention (at the conclusion of the central venous catheterization procedure)

• Patient Satisfaction Score

  Post-intervention (at the conclusion of the central venous catheterization procedure)

• Incidence of Treatment-Related Adverse Events

  From the start of the intervention through 30 minutes post-procedure

Study Arms (2)

Nitrous Oxide Group

EXPERIMENTAL

This will be the experimental group in which the patients will receive a mixture of gases to assess the efficacy of the treatment compared to the control.

Drug: Nitrous Oxide-Oxygen

Lidocaine 2%

ACTIVE COMPARATOR

The control group receiving the standard of care for this intervention.

Drug: Lidocaine 2% Injectable Solution

Interventions

Nitrous Oxide-Oxygen DRUG

After placing the patient in the appropriate supination + Trendelenburg position, the operative field (neck and subclavian region) is prepared using antiseptic measures.Five minutes before needle insertion, a mask connected to a 50:50 Nitrous Oxide/Oxygen cylinder with a flow rate of 6 liters per minute is placed on the patient's face and held by the patient. The mask has a valve that opens only when the patient creates negative pressure during inhalation.The patient is instructed to breathe spontaneously; the mask is removed once the catheter is inserted into the target vein or after cessation of painful stimulation.

Also known as: Experimental Treatment

Nitrous Oxide Group

Lidocaine 2% Injectable Solution DRUG

After placing the patient in the appropriate supination + Trendelenburg position, the operative field (neck and subclavian region) is prepared using antiseptic measures. Then, under ultrasound control, the most favorable central vein for puncture is determined (v. jugularis interna or v. subclavia) and a 25-gauge needle is used to infiltrate the skin and subcutaneous tissue above the selected vein with local anesthetic. Five minutes after infiltration, puncture of the selected vein is performed using the Seldinger technique. Continuous communication with the patient is maintained throughout the procedure.

Also known as: Control

Lidocaine 2%

Eligibility Criteria

• Age: 18 Years - 65 Years
• Sex: all
• Healthy Volunteers: Yes
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• Subjects who have not previously received Nitrous Oxide.
• Subjects of both sexes, aged between 18 and 65 inclusive.
• Subjects who have signed informed consent with full disclosure; no study-related procedure may begin until the subject signs the consent form.

You may not qualify if:

• Infection at the planned puncture site.
• Pregnancy.
• Intracranial hypertension.
• Vitamin B12 deficiency.
• Hemodynamic instability.
• BMI over 35.
• Glasgow Coma Scale (GCS) score less than 15.
• Presence of chronic pain.
• Neurological disorders.
• Hematologic disorders.
• More than two attempts at venous puncture (Subject Withdrawal Criterion).
• Subject experienced an adverse event requiring early discontinuation (Subject Withdrawal Criterion).
• Withdrawal of consent by the subject (Subject Withdrawal Criterion)

Sponsors & Collaborators

• Institute for Oncology and Radiology of Serbia: lead

Study Sites (1)

Institute for Oncology and Radiology of Serbia

Belgrade, Savski Venac, 11000, Serbia

RECRUITING

MeSH Terms

Conditions

Acute Pain; Anxiety Disorders

Interventions

Lidocaine

Condition Hierarchy (Ancestors)

Pain; Neurologic Manifestations; Signs and Symptoms; Pathological Conditions, Signs and Symptoms; Mental Disorders

Intervention Hierarchy (Ancestors)

Acetanilides; Anilides; Amides; Organic Chemicals; Aniline Compounds; Amines

Study Officials

• Ana Cvetković, MD, PhD

  Institute for Oncology and Radiology of Serbia

  PRINCIPAL INVESTIGATOR

Central Study Contacts

Ana Cvetkovic, MD,PhD

CONTACT

+381 11 2067 100; ana.cvetkovic@ncrc.ac.rs

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: RANDOMIZED
• Masking: SINGLE
• Who Masked: OUTCOMES ASSESSOR
• Purpose: TREATMENT
• Intervention Model: PARALLEL
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Head of the Department of Anesthesia

Study Record Dates

• First Submitted: May 25, 2026
• First Posted: June 1, 2026
• Study Start: June 6, 2025
• Primary Completion: June 6, 2026
• Study Completion (Estimated): July 1, 2026
• Last Updated: June 1, 2026

Record last verified: 2026-05

Data Sharing

• IPD Sharing: Will not share

Locations

SE (1)