Nitrous Oxide for Pain Management of First Trimester Surgical Abortion

Not Applicable

Completed

Brief Summary: The purpose of this research is to study the effect of nitrous oxide on pain felt by women having a surgical termination at less than 11 weeks compared to pain felt by women receiving oral pain medications.

Detailed Description: This study has important implications in the field of pain management for surgical abortion. While NO is administered in some outpatient clinics for surgical abortion, its effect on pain has not been systematically studied in a randomized controlled trial in women undergoing first trimester surgical abortion under local/oral analgesia. Expanding pain management options for women undergoing abortion confers significant public health benefits.

Recruitment & Eligibility

Inclusion Criteria

18 years old or older,
elective pregnancy termination at gestational age of less than 11 weeks,
speak English
candidate for an in-clinic procedure.
desire local anesthesia, ibuprofen, Vicodin and Ativan (the usual treatment in our clinic) for managing pain

Exclusion Criteria

no medical problems preventing the use of nitrous oxide
no allergies to nitrous oxide, lidocaine, vasopressin, ibuprofen, Vicodin or Ativan
significant active upper respiratory infection
chronic obstructive pulmonary disease (COPD)
intoxication
use of street drugs

Arm && Interventions

Group	Intervention	Description
Nitrous oxide administration	Nitrous oxide administration	All participants will receive 800 mg of oral ibuprofen 30 minutes pre-operatively. All patients will receive local anesthesia via a standardized paracervical block with 18 cc of 1% lidocaine buffered with 2 ml of 8.4% sodium bicarbonate and 0.2 ml of 4 units of vasopressin. In addition, the Nitrous oxide group will receive two placebo pills. Nitrous oxide will be administered via a disposable scented nasal mask to blind patients to the intervention. Nitrous oxide will be administered at a fixed ratio of 60% nitrous oxide and 40% oxygen. The nasal mask will be placed on the patient's nose and the nitrous oxide will be administered continuously.

Primary Outcome Measures

Name	Time	Method
Visual Analog Pain Score for Mean Maximum Procedural Pain	Mean maximum pain experienced during the procedure and assessed 5 minutes after the procedure	The primary outcome of this study is to evaluate the difference in mean maximum pain experienced during the procedure between groups as assessed 5 minutes after the procedure is completed. Pain was assessed using the Visual Analog Scale (VAS). 0 = no pain, 100 = maximum pain

Secondary Outcome Measures

Name	Time	Method
Visual Analog Scale Score for Baseline Pain	Baseline pain assessment on average within 30 minutes before procedure	A quantitative assessment of pain prior to the procedure. Pain was assessed using the Visual Analog Scale (VAS). 0 = no pain, 100 = maximum pain
Visual Analog Scale for Post-procedure Pain	Visual analog scale administered on average 20 minutes after procedure completed	A quantitative assessment of post-procedure pain. Pain was assessed using the Visual Analog Scale (VAS). 0 = no pain, 100 = maximum pain
Pain Management Satisfaction	Visual analog scale for satisfaction administered on average within 20 minutes after procedure completion.	Quantitative assessment of pain management. Pain was assessed using the Visual Analog Scale (VAS). 0 = no pain, 100 = maximum pain
Visual Analog Scale to Measure Anticipated Pain.	Anticipated pain assessed on average within 30 minutes before procedure	Anticipated pain is assessed before the procedure. Pain was assessed using the Visual Analog Scale (VAS). 0 = no pain, 100 = maximum pain