Nitrous Oxide for Pain Management of First Trimester Surgical Abortion (NAB)

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.

Study Overview

• Status: Completed
• Conditions: Abortion in First Trimester
• Intervention / Treatment: Other: Nitrous oxide administration

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.

• Study Type: Interventional
• Enrollment (Actual): 140
• Phase: Not Applicable

Contacts and Locations

Study Locations

• United States
  • New Mexico
    • Albuquerque, New Mexico, United States, 87131
      • University of New Mexico Health Sciences Center

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years and older (Adult, Older Adult)
• Accepts Healthy Volunteers: Yes
• Genders Eligible for Study: Female

Description

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

Study Plan

How is the study designed?

Design Details

• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Double

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: 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.	Other: Nitrous oxide administration; All participants will receive 800 mg of oral ibuprofen 30 minutes pre-operatively. The NO group will get two placebo pills and the standard care group will get one 5/325 mg Vicodin, and 1 mg of Ativan 30 minutes before the procedure. The standard care group will get oxygen intraoperatively. NO or oxygen will be administered via a scented nasal mask to blind patients to the intervention. All patients will get local anesthesia via a standardized PCB.
No Intervention: Standard care group; 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. The standard care group will receive one 5/325 mg Percocet, and 1 mg of lorazepam, 30 minutes before the procedure. The standard care group will receive oxygen by mask intraoperatively.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Visual Analog Pain Score for Mean Maximum Procedural Pain	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	Mean maximum pain experienced during the procedure and assessed 5 minutes after the procedure

Secondary Outcome Measures

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

Collaborators and Investigators

• Sponsor: University of New Mexico
• Investigators: Principal Investigator: Rameet H. Singh, MD, MPH, University of New Mexico Health Sciences Center

Publications and helpful links

General Publications

• Singh RH, Espey E, Carr S, Pereda B, Ogburn T, Leeman L. Nitrous oxide for pain management of first trimester surgical abortion -- a randomized controlled pilot study. Contraception. 2015 Feb;91(2):164-6. doi: 10.1016/j.contraception.2014.09.013. Epub 2014 Oct 22.

Study record dates

Study Major Dates

• Study Start: August 1, 2012
• Primary Completion (Actual): April 1, 2015
• Study Completion (Actual): April 1, 2015

Study Registration Dates

• First Submitted: March 20, 2014
• First Submitted That Met QC Criteria: March 23, 2014
• First Posted (Estimate): March 26, 2014

Study Record Updates

• Last Update Posted (Estimate): April 19, 2016
• Last Update Submitted That Met QC Criteria: April 15, 2016
• Last Verified: April 1, 2016

More Information

Terms related to this study

• Keywords: pain; nitrous oxide
• Additional Relevant MeSH Terms: Physiological Effects of Drugs; Central Nervous System Depressants; Peripheral Nervous System Agents; Analgesics; Sensory System Agents; Anesthetics, General; Anesthetics; Analgesics, Non-Narcotic; Anesthetics, Inhalation; Nitrous Oxide
• Other Study ID Numbers: UNMHSC12-313