This study seeks to determine the effectiveness of nitrous oxide in reducing the anxiety and pain associated with external cephalic version (ECV); a maneuver to turn the fetus from breech to cephalic position.
Study Procedures: Potential subjects will be identified as they are scheduled to undergo ECV at the UNC Department of Obstetrics and Gynecology. Subjects will be enrolled in the study by one of the study investigators. Details of the study will be reviewed with potential subjects and those wishing to enroll in the study will be consented for the study by one of the study investigators. Once enrolled participants will be randomized to receive either a mixture of 50% nitrous oxide in 50% oxygen or 100% oxygen, both of which will be delivered via the Nitronox apparatus. Demographic variables will be recorded for each participant at the time they are enrolled in the study The Nitronox apparatus will be set up to deliver either 50% nitrous oxide in 50% oxygen or 100% oxygen by an anesthesia provider covering labor and delivery who is not involved in the study. The Nitronox device will be covered to prevent participants, study investigators and obstetricians performing the procedure from knowing whether nitrous oxide is being delivered. Nitrous oxide is odorless and colorless, so in that way is indistinguishable from oxygen. Participants will be prepared for ECV according to current protocols for ECV at UNC. IV access will be obtained and tocolytic agents will be given according to current practice and protocols. Monitoring of maternal and fetal vital signs will be done according to current protocols. Immediately before an ECV attempt participants will breathe through the facemask of the Nitronox device for 30 seconds and will then be free to use the device ad lib during the ECV attempt. Immediately following each attempt, while fetal monitoring is occurring, the participants will be asked to rate their maximum pain score during the previous attempt. They will also be asked to rate their current level of anxiety. This process will be repeated for any further ECV attempts. At conclusion of all ECV attempts, while fetal monitoring is occurring, the participants will be asked to rate their current level of pain, their satisfaction with the procedure and about any side effects they experienced (nausea, vomiting, dizziness, headache, other). Participants will continue to be monitored on labor and delivery as current protocol dictates, typically 30 minutes of maternal and fetal monitoring if there are no complications and fetal status is reassuring. Following the procedure, the obstetrician who performed the procedure will be asked to rate how difficult they felt it was to perform the procedure and to rate how much they felt the analgesic provided assisted in performing the procedure. They will also be asked to indicate whether they thought the patient was in the treatment or placebo arm of the study. This will be recorded to address the adequacy of blinding. All study variables will be assessed and recorded by one of the study investigators to ensure consistency in data collection.
Study Type
INTERVENTIONAL
Allocation
RANDOMIZED
Purpose
TREATMENT
Masking
QUADRUPLE
Enrollment
48
50% nitrous oxide/50% oxygen via Nitronox delivery device
100% oxygen via Nitronox delivery device
University of North Carolina
Chapel Hill, North Carolina, United States
Mean Pain Score Experienced During Version
Pain scores will be collected following each version attempt using an 11 point scale (with 0 being no pain at all; 10 being worst pain imaginable), ranging from 0 to 10. Higher scores indicate more pain, lower scores indicate less pain. If more than one attempt, pain scores will be averaged to obtain a single score for the entire procedure.
Time frame: During each version procedure, a total average of up to approximately 30 minutes
Mean Anxiety Score Experienced During Version
Anxiety scores will be collected following each version attempt using an 11 point scale (0 being not at all anxious; 10 being extremely anxious), ranging from 0 to 10. Higher scores indicate more anxiety, lower scores indicate less anxiety. If more than one attempt, anxiety scores will be averaged to obtain a single score for the entire procedure.
Time frame: During each version procedure, a total average of up to approximately 30 minutes
Mean Post-procedure Pain Score
Pain scores will be collected following completion of the version using an 11 point scale (0 being no pain at all; 10 being worst pain imaginable), ranging from 0 to 10. Higher scores indicate more pain, lower scores indicate less pain.
Time frame: Immediately Post-procedure, within approximately 15 minutes of final version attempt
Mean Post-procedure Patient Satisfaction Score
Satisfaction will be assessed following the procedure using an 11 point scale (0 being not at all satisfied; 10 being extremely satisfied), ranging from 0 to 10. Higher scores indicate more satisfaction, lower scores indicate less satisfaction.
Time frame: Immediately Post-procedure, within approximately 15 minutes of final version attempt
Mean Post-procedure Provider Assessed Level of Difficulty Score
This platform is for informational purposes only and does not constitute medical advice. Always consult a qualified healthcare professional.
Following the procedure, the obstetric provider performing the procedure will rate the ease of procedure on a 1-10 scale (1 being very easy and 10 being extremely difficult), ranging from 1 to 10. Higher scores indicate more difficulty, lower scores indicate less difficulty. A 10 point scale was used for this outcome, while an 11 point scale was used for the other 4 outcome measures (pain, anxiety, post-procedure pain and satisfaction).
Time frame: Immediately Post-procedure, within approximately 15 minutes of final version attempt