A Single-centre Study of Entonox Versus Midazolam Sedation in Gastroscopy

The safety and scientific validity of this study is the responsibility of the study sponsor and investigators. Listing a study does not mean it has been evaluated by the U.S. Federal Government. Read our disclaimer for details. Identifier: NCT01744184
Recruitment Status : Suspended (Resource issues)
First Posted : December 6, 2012
Last Update Posted : April 12, 2017
Information provided by (Responsible Party):
The Royal Bournemouth Hospital

Brief Summary:
This study aims to determine whether Entonox (gas and air) is at least as good as intravenous midazolam in providing analgesia and sedation during gastroscopy. Entonox is used as an adjunct in lower gastrointestinal procedures but is not routinely used in gastroscopy, and there is only one similar published study to date, which was performed in children. The main advantage of Entonox over midazolam is the quick recovery time following withdrawal of the agent, which enables patients to return to independent normal life. The investigators would like to be able to offer Entonox to patients as an option for sedation during gastroscopy, this study is being conducted to determine if it is a safe and feasible option.

Condition or disease Intervention/treatment Phase
Patients Requiring Diagnostic Gastroscopy With Sedation Drug: Entonox Drug: Midazolam Phase 4

Study Type : Interventional  (Clinical Trial)
Estimated Enrollment : 200 participants
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: None (Open Label)
Primary Purpose: Treatment
Official Title: A Single-centre, Randomised Controlled Study of Entonox Versus Midazolam Sedation in Gastroscopy.
Study Start Date : May 2013
Estimated Primary Completion Date : April 2018
Estimated Study Completion Date : December 2018

Resource links provided by the National Library of Medicine

U.S. FDA Resources

Arm Intervention/treatment
Active Comparator: Midazolam

midazolam sedation combined with pharyngeal anaesthesia

Participants randomized to receive midazolam will have an intravenous cannula sited and, following the administration of xylocaine throat spray as above, will be put into the left lateral position. They will then be given up to 5mg midazolam as appropriate to achieve conscious sedation as for standard protocol in endoscopy.

Drug: Midazolam
up to 5mg midazolam as appropriate
Other Name: Midazolam 1mg/ml Solution for Injection
Experimental: Entonox

Entonox combined with pharyngeal anaesthesia.

Pharyngeal anaesthesia, given as 8-16 sprays of xylocaine to the pharynx; 3 minutes will be given to allow the pharynx to become anaesthetized.

Participants randomized to receive Entonox will be given the 50:50 nitrous oxide:oxygen mix via a mouthpiece with a demand valve system, once in position for the procedure. Inhalations will be given for 3-5 minutes (or until the participant feels adequately sedated) measured using a stopwatch. Oxygen will be given at 2 litres per minute via nasal cannulae during the procedure, (standard care for sedated procedures). The endoscopist will then proceed to intubate the cricopharynx and perform the procedure in the standard manner.

Drug: Entonox
Entonox arm
Other Names:
  • Oxygen 50.0% +/- 2.0%
  • Nitrous oxide 50.0% +/- 2.0%

Primary Outcome Measures :
  1. Patient comfort during gastroscopy [ Time Frame: During gastroscopy procedure ]
    Patient comfort during gastroscopy confirmed by post procedural questionnaire completion

Secondary Outcome Measures :
  1. Number of completed procedures in both arms of the study. [ Time Frame: 3 months ]
    The number of completed procedures in both arms of the study confirmed by data collection.

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Ages Eligible for Study:   18 Years and older   (Adult, Senior)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   No

Inclusion Criteria:

  • Male/female aged 18 years or over
  • Confirmed clinical requirement to undergo diagnostic gastroscopy
  • Suitable for sedation
  • Able to provide informed consent

Exclusion Criteria:

  • History of chronic respiratory or significant cardiac disease
  • Requirement for longer procedure eg Barrett's surveillance
  • Previous known adverse reaction to Entonox
  • Entonox use in previous 4 days
  • Known current vitamin B12 or folate deficiency
  • Unable to provide consent
  • Any known contraindication to Entonox:
  • Gas trapped in a part of the body where its expansion may be dangerous, such as air lodged in an artery or artificial traumatic or spontaneous pneumothorax (collapsed lung).
  • Decompression sickness (the bends) or following a recent dive
  • Air encephalography
  • Severe bullous emphysema
  • Myringoplasty
  • Gross abdominal distension
  • Recent severe injuries to the face and jaw
  • Current or recent head injuries
  • If the patient has recently had any eye surgery where injections of gas have been used

Information from the National Library of Medicine

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.

Please refer to this study by its identifier (NCT number): NCT01744184

United Kingdom
The Royal Bournemouth and Christchurch Hospitals NHS Foundation Trust
Bournemouth, Dorset, United Kingdom, BH7 7DW
Sponsors and Collaborators
The Royal Bournemouth Hospital
Principal Investigator: Simon McLaughlin, MD The Royal Bournemouth and Christchurch Hospitals NHS Foundation Trust

Responsible Party: The Royal Bournemouth Hospital Identifier: NCT01744184     History of Changes
Other Study ID Numbers: ENT1
First Posted: December 6, 2012    Key Record Dates
Last Update Posted: April 12, 2017
Last Verified: April 2017

Keywords provided by The Royal Bournemouth Hospital:

Additional relevant MeSH terms:
Nitrous Oxide
Adjuvants, Anesthesia
Hypnotics and Sedatives
Central Nervous System Depressants
Physiological Effects of Drugs
Anti-Anxiety Agents
Tranquilizing Agents
Psychotropic Drugs
Anesthetics, Intravenous
Anesthetics, General
GABA Modulators
GABA Agents
Neurotransmitter Agents
Molecular Mechanisms of Pharmacological Action
Anesthetics, Inhalation
Analgesics, Non-Narcotic
Sensory System Agents
Peripheral Nervous System Agents
Anesthetics, Combined