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

The Royal Bournemouth Hospital

Status and phase: Terminated; Phase 4

Conditions: Patients Requiring Diagnostic Gastroscopy With Sedation

Treatments: Drug: Midazolam; Drug: Entonox

Study type: Interventional

Funder types: Other

Identifiers

NCT01744184

ENT1

Details and patient eligibility

About

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.

Enrollment: 62 patients

Sex: All

Ages: 18+ years old

Volunteers: No Healthy Volunteers

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

Trial design

Primary purpose: Treatment

Allocation: Randomized

Interventional model: Parallel Assignment

Masking: None (Open label)

---

62 participants in 2 patient groups

Midazolam

Active Comparator group

Description:

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.

Treatment:

Drug: Midazolam

Entonox

Experimental group

Description:

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.

Treatment:

Drug: Entonox