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
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)
