Comparative Analysis of CO2 Monitoring Methods in Patients With CF Undergoing General Anesthesia
Phase: NA
Conditions: Cystic Fibrosis
Sponsor: Nationwide Children's Hospital

 
Comparative Analysis of CO2 Monitoring Methods in Patients with CF Undergoing 
General Anesthesia 
 
NCT03734822 
 
September 22, 2015 
 
 

PROTOCOL 
 
Title:  Comparative Analysis of CO2 Monitoring Methods in Patients with CF Undergoing 
General Anesthesia 
 
CO-PI’s:  Anne May, MD and Joseph Tobias, MD 
 
Introduction: 
 
CO2 measurements obtained using different methodologies are used as a marker for ventilatory 
status in various clinical settings.  Accuracy of CO2 measurements is especially important in 
cystic fibrosis patients.  During procedures requiring general anesthesia, CO2 is monitored 
through the endotracheal tube (EtCO2) and/or arterial blood gas (ABG) and anesthesia adjusted 
to maintain healthy CO2 levels.  Outside of the operating room, fingerstick capillary (CapCO2) 
or transcutaneous (TCO2) are used to manage other treatments in cystic fibrosis patients.  
Unfortunately, there are very little data in the literature to compare and contrast accuracy of the 
differing methodologies.  Comparative studies are needed to identify the most accurate method 
for measuring CO2 in various settings.  This study will obtain CO2 measurements 
simultaneously using four different methodologies (EtCO2, ABG, CapCO2, and TCO2) in cystic 
fibrosis patients undergoing general anesthesia. 
 
Primary Objectives: 
 
1. Validate the use of EtCO2 monitoring of cystic fibrosis patients during general anesthesia. 
2. Compare the results of EtCO2 with CapCO2, TCO2 and ABG in CF patients undergoing 
general anesthesia. 
 
Secondary Objective: 
 
1. Stratify CF patients based on FEV1 and genotype to determine if discrepancies between 
EtCO2, CapCO2, TCO2, and ABG change based on level and type of disease.  This 
comparative study will use data FEV1 and genotype data collected through separate chart 
review. 
 
 
Study Population: 
 
All patients that have a confirmed diagnosis of cystic fibrosis (positive sweat chloride value ≥ 60 
mEq/L) and/or genotype with two identifiable mutations consistent with CF, accompanied by one 
or more clinical features consistent with the CF phenotype) and are hemodynamically stable 
undergoing general anesthesia for a scheduled procedure will be approached and asked to 
participate in the study.  Patients undergoing emergency procedures will not be included in the 
study.  Patients meeting the criteria for participation will be identified during their CF clinic visit 
or during an inpatient stay.   
 
Procedures: 
 
1. When a patient is scheduled for a procedure requiring general anesthesia, a secure 
message will be sent to Julie Rice, Sam Barry, Heather Dellinger, and Linda Humston with 
patient identification, date and time of procedure. 

2. Just prior to the procedure, an anesthesia research nurse will obtain informed 
consent/assent for the study. 
3. After anesthesia induction, simultaneous EtCO2, ABG, TCO2, and CapCO2 will be 
measured and results entered on a data form attached to the signed consent.   
4. The research nurse will place the signed consent form and the data form in a locked file 
cabinet in anesthesia. 
5. Linda Humston from Pulmonary Medicine will pick up the documents from anesthesia and 
enter the information into the password-protected study database.  No patient identifiers will 
be entered into the database.