Colonoscopy Using Nitrous Oxide- A Pilot Study in the USA

  • End date
    Nov 13, 2022
  • participants needed
  • sponsor
    University of Arkansas
Updated on 13 June 2022
Accepts healthy volunteers


Colon cancer is the second most common cancer in men and the third most common cancer in women worldwide. The clinical objectives of administering sedation for GI endoscopy are to relieve patient anxiety and discomfort and to improve the outcome of the examination. Use of N2O could potentially provide an alternate safe and cheap option for patients who do not prefer IV sedation for colonoscopy


Patients who are considered low risk for anesthesia administration (ASA class <IV) receive moderate sedation with a combination of intravenous benzodiazepine and opioid medication. an alternative method of providing analgesia with "on-demand" inhalation of nitrous oxide (hereafter referred to as N2O) combined with oxygen has been postulated. Nitrous Oxide has been used for analgesia in various procedures including childbirth, general anesthesia, pediatric dentistry, bone marrow aspiration, fracture reductions, and minor surgical procedures (surgical dressings, pulmonary endoscopy, an abscess . It could potentially reduce overall costs for the procedure, in addition to providing a quicker recovery, turn over

Condition Nitrous Oxide
Treatment Nitrous Oxide
Clinical Study IdentifierNCT04305158
SponsorUniversity of Arkansas
Last Modified on13 June 2022


Yes No Not Sure

Inclusion Criteria

Men and women, more than 18 years old Scheduled for a colonoscopy at the
Endoscopy unit

Exclusion Criteria

High ASA risk (IV/ >)
History of chronic pain
Allergy to N2O or opioid or BDZ
No consent
Recent head injury with impairment of consciousness or Intracranial / Middle Ear surgery within the previous 6 months with or without residual deficits
Pneumothorax, air embolism
Decompression sickness or within 48 hours of an underwater dive
Severe emphysema with bullae
Gross abdominal distension with suspicion for bowel obstruction
Maxillofacial injuries (where patient unable to administer the drug using a mouthpiece/mask, or there is the risk of causing further damage to facial wounds and there may also be a significant risk of blood inhalation)
Patients with chronic pulmonary disease for whom an inspired oxygen concentration of more than 28% oxygen might be dangerous
Patients on Methotrexate
Where patients need assistance to hold the mask or mouthpiece
Retinal surgery within the last three months
Any patient who does not otherwise clinically qualify for standard sedation methods (i.e., those who require general anesthesia)
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