CO2 vs. Air Insufflation for Endoscopic Ultrasound
Condition: Lesion; Gastrointestinal; Liver, Biliary, Pancreas and Gastrointestinal Disease, Nos
MeSH terms: Gastrointestinal Diseases; Digestive System Diseases
Study type: Observational

Summary: 
      The insufflation of air in the viscera is indispensable during endoscopy. However, the
      distension of the bowel that follows is often the cause of abdominal discomfort.

      Carbon dioxide (CO2) has been widely used for insufflation in endoscopy. CO2 insufflation is
      demonstrated in the literature to cause lower abdominal discomfort as it is quickly
      reabsorbed by the body.

      Endoscopic ultrasonography (EUS) is a method in which you associate the endoscopic view and
      the ultrasound vision obtained from the inside of the viscera.

      The diagnostic accuracy of EUS is undermined by the visual artifacts caused by the presence
      of air between the probe and the organ to be studied.

      Although the use of CO2 is already widely applied by many endoscopists, there are no studies
      to date concerning the use of CO2 during EUS from the point of view of the abdominal
      discomfort related to the procedure and/or the quality of the images obtained.

      The main purpose of the study is to assess whether the insufflation of CO2 results in a
      reduction of discomfort of the patients undergoing EUS. The study design is observational
      because no randomization or other interventions are planned; participants will be assigned to
      either air or CO2 insufflation according to the endoscopic room equipment (one room is
      equipped with CO2 insufflation while another endoscopic room is equipped just with air
      insufflation) and the results of the two groups will be compared. Among the secondary goals
      the investigators want to evaluate whether insufflation of CO2 is associated with a reduction
      in the dose required for patients sedation. Finally, the investigators want to clarify
      whether the use of CO2 is able to produce less visual artifacts than air and thus improve the
      quality of EUS images.
    

Detailed description: 
      The insufflation of air in the viscera during endoscopy is indispensable in order to allow
      the advancement of endoscopic probe, to visualize the mucosa and to avoid injury to the
      gastrointestinal wall. However, the distension of the bowel that follows is often the cause
      of abdominal discomfort since the air blown appears to be slightly absorbable and therefore
      it needs a long time to be expelled.

      Carbon dioxide (CO2) is a gas that has already been widely used for insufflation in
      endoscopy. CO2 insufflation is demonstrated in the literature to cause lower abdominal
      discomfort as it is quickly reabsorbed by the body. This gas is at the same time devoid of
      side effects.

      Studies in the literature focus mainly on the intensity of abdominal discomfort after the
      insufflation of CO2 vs. air while performing colonoscopy, endoscopic retrograde
      cholangiopancreatography (ERCP) and enteroscopy.

      Endoscopic ultrasonography (EUS) is a method in which you associate the endoscopic view and
      the ultrasound vision obtained from the inside of the viscera. The main indications to EUS
      are represented by the study of the biliary pancreatic diseases, the staging of the digestive
      tract tumors and the differential diagnosis of submucosal tumors.

      The diagnostic accuracy of EUS is undermined by the visual artifacts caused by the presence
      of air between the probe and the organ to be studied; during the procedure the endoscopist
      must ensure, by means of repeated suctions, that the least possible amount of air is present
      inside the viscera.

      Although the use of CO2 is already widely applied by many endoscopists, there are no studies
      to date concerning the use of CO2 during EUS from the point of view of the abdominal
      discomfort related to the procedure and/or the quality of the images obtained.

      At the moment, with regard to EUS, there are no recommendations regarding the use of a gas
      rather than the other; the choice is in fact at the discretion of the operator and also it
      depends on the availability in the individual endoscopic units of the instrumentation for CO2
      insufflation.

      At Our Endoscopic Unit, CO2 or air insufflation is decided upon the availability of the
      equipment in the endoscopic room; in particular, in Suite 1, patients receive air
      insufflation and in Suite 2 they receive CO2 insufflation. The assignment into one or the
      other endoscopic room is purely casual according to scheduling the next free available slot.

      The main purpose of the study is to assess whether there is any difference between CO2 and
      air insufflation in inducing discomfort of the patients undergoing EUS. The study design is
      observational because no randomization or other intervention modifications are planned;
      participants will be assigned to either air or CO2 insufflation according to the endoscopic
      room equipment (one room is equipped with CO2 insufflation while another endoscopic room is
      equipped just with air insufflation) and the results of the two groups will be compared.
      Among the secondary goals the investigators want to evaluate whether insufflation of CO2 is
      associated with a reduction in the dose required for patients sedation. Finally, the
      investigators want to clarify whether the use of CO2 is able to produce less visual artifacts
      than air and thus improve the quality of EUS images.
    

Intervention name(s): EUS with air insufflation; EUS with CO2 insufflation
Intervention type(s): Other; Other
Intervention description(s): Diagnostic procedure using an echoendoscope for the study of pancreaticobiliary or gastrointestinal diseases using air insufflation; Diagnostic procedure using an echoendoscope for the study of pancreaticobiliary or gastrointestinal diseases using CO2 insufflation
Observational model: Case-Control
Time perspective: Prospective
Sampling method: Non-Probability Sample
Study population: 
        Patients with indications for undergoing EUS (in general they are represented by patients
        with pancreaticobiliary or gastrointestinal diseases)