The Safety and Efficacy of Carbon Dioxide for Insufflation During Endoscopy in Pediatric Patients
Phase: PHASE4
Conditions: Endoscopy, Insufflation
Sponsor: Warren Bishop

Cover page 
Title: Safety and Efficacy of CO2 for Endoscopy 
NCT 03287687 
1/1/2020 
 
 
Study Protocol: 
The current literature in pediatric endoscopy does not include evidence on effectiveness and 
safety of CO2 insufflation in procedures besides colonoscopy and does not include children in 
the younger age range. Esophagogastroduodenoscopy procedures (EGDs) are much more 
commonly performed procedures in children so it is important to assess these clinical scenarios 
before adopting CO2 insufflation as the main mode of practice.   
Our study aimed to address these knowledge gaps by enrolling younger children, including 
infants, and a wide variety of endoscopic procedures, including EGDs and percutaneous 
endoscopic gastrostomy (PEG) tube placement.  
 
Study Design 
This is a double-blinded, prospective, randomized study comparing CO2 and air for insufflation 
during endoscopic procedures in pediatric patients performed in the Pediatric Endoscopy Unit at 
the University of Iowa Children’s Hospital.  The study was approved by the Institutional Review 
Board (IRB) at the University of Iowa  
 
Subjects and Randomization 
Patients aged 6 months to 21 years undergoing diagnostic or therapeutic endoscopic procedures 
were offered participation.  These procedures included EGD, colonoscopy, PEG tube placement, 
and endoscopic PEG tube exchange.  Exclusion criteria included non-English-speaking families 
needing an interpreter and patients with significant chronic lung disease, such as 
bronchopulmonary dysplasia, severe asthma, or cystic fibrosis.  Consents and assents were 
obtained proper to enrollment. 
Both the patient and endoscopist were blinded to the arm of study. Randomization was done by 
the procedure suite nurse using a sealed envelope system. To maintain allocation concealment, 
the nurse set up the equipment to deliver CO2 or air then covered the relevant equipment settings 

to assure complete blinding of the endoscopist and others in the room. The equipment was 
adjusted to deliver CO2 or air at a similar flow rate. 
Data Collection 
Collected data included patient demographics (age, sex, growth parameters), procedure 
indication, patient’s overall health status based on the American Society of Anesthesiologists 
(ASA) classification, endoscopy-related characteristics (duration, trainee vs faculty endoscopist 
and complications) and anesthesia-related parameters (duration, medication dosing, and 
complications). Vital signs, including EtCO2, heart rate, respiratory rate, oxygen saturation, and 
blood pressure were monitored and automatically recorded continuously throughout the 
procedure, according to the anesthesia protocol. EtCO2 was monitored and continuously 
sampled by nasal prong or via capnography for intubated patients. 
 
Outcome Measures 
Patient discomfort was assessed using 3 scales: 
1. Face, Legs, Activity, Cry, and Ability to be Consoled (FLACC) behavioral assessment score 
2. Global Parent Perception of Pain (PPP) scale 
3. FACES scale; for neurodevelopmentally appropriate children 5 years and older. 
 
Pain 
FLACC at baseline, within 15 minutes of return to recovery area, when awake. FLACC scores 
categorized as no pain, mild pain, moderate to severe pain, very severe pain or worst pain ever 
PPP at baseline, when awake and 4 hours post discharge. PPP scores categorized as no pain, mild 
pain, moderate to severe pain, very severe pain or worst pain ever 
VAS at baseline, when awake and 4 hours post discharge. VAS scores categorized as no pain, 
mild pain, moderate to severe pain, very severe pain or worst pain ever 
Abdominal girth at baseline, after procedure, at discharge, and 4 hours post discharge 
 
Endoscopist assessment  
Perceived ease of inflation: easy or average, mild difficulty, very difficult 

Perceived patient discomfort: comfortable or average discomfort, above average discomfort 
Endoscopist guess of inflation gas 
 
Abdominal girth was measured by the same nurse at the level of the umbilicus before the 
procedure, immediately upon arrival in the recovery area after the procedure, and again just 
before discharge. Patients were sent home with a tape measure and a postage-prepaid response 
card on which they recorded the abdominal girth four hours after completion of the procedure. 
Parents were also asked to indicate if the patient had experienced belching, bloating or 
flatulence.   
 
Sedation for all procedures was provided by an anesthesia team lead by a pediatric 
anesthesiologist, who was also blinded to the study group allocation. For most patients, 
anesthesia consisting of a continuous propofol infusion without an advanced airway such as 
endotracheal intubation was used. When indicated, based on the patient and procedure 
characteristics, general anesthesia with endotracheal intubation was occasionally used. 
Data were entered into Redcap software. Adverse events defined as any undesired event 
occurring during endoscopy, and sedation-related complications such as hypoxia and aspiration 
were reported at regular intervals to the IRB during enrollment.