Colonoscopy Using Nitrous Oxide- A Pilot Study in the USA

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

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
• Intoxication
• 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)