title: A fixed inhaled nitrous oxide/oxygen mixture as an analgesic for adult cancer patients with breakthrough pain: study protocol for a randomized controlled trial.
abstract: The management of breakthrough pain in cancer patients is always a challenge for medical professions. Occurring in 80% of cancer patients with advanced disease, breakthrough pain significantly decreases both patient's and caregiver's quality of life. The aim of this study is to assess the analgesic efficacy of a fixed inhaled nitrous oxide/oxygen mixture for adult cancer patients with breakthrough pain.
  
  
  
  This is a randomized, placebo-controlled, double-blind study; it will be conducted in the General Hospital of Ningxia Medical University. The target study subjects are at least 18 years old, and are hospitalized cancer patients who are receiving routine opioids to control cancer-related pain but still experience breakthrough pain. A total of 240 patients will be recruited and randomly allocated between three treatment groups (A, B, C) and a control group (group D) in a ratio of 3:1. All treatment groups (A, B, C) will receive standard pain treatment (oral immediate-release morphine) plus a pre-prepared nitrous oxide/oxygen mixture, and the control group (D) will receive the standard pain treatment plus oxygen. Patients, doctors, nurses, and data collectors are all blind to the experiment. Assessments will be taken before treatment (T0), at 5 min (T1) and 15 min (T2) during treatment, and at 5 min after treatment (T3). The primary endpoint measures will be the percentage of patients whose pain is relieved at T1, T2, and T3. Secondary outcome measures will include the safety of treatment, adverse events, and satisfaction from both health professionals and patients.
  
  
  
  This study aims to provide an effective and practical intervention for a fast breakthrough pain relief and to improve cancer patients' quality of life significantly. The Evidence-Based Medicine Working Group claim that a randomized, double-blind, placebo-controlled experimental intervention is the most appropriate design to demonstrate its efficacy, so this study could give a new approach to controlling breakthrough pain episodes.
  
  
  
  ChiCTR-INC-16008075 . Registered on 8 March 2016.
authors.affiliation: School of Nursing, Ningxia Medical University, 1160 Sheng Li Street, Yinchuan, 750004, China.|Yinchuan Guolong Hospital, 536 Chang Cheng Road, Xing Qing Area, Yinchuan, 750004, China.
authors.forename: Qiang
authors.initials: Q
authors.lastname: Liu
authors.affiliation: School of Nursing, Ningxia Medical University, 1160 Sheng Li Street, Yinchuan, 750004, China.
authors.forename: Yu
authors.initials: Y
authors.lastname: Wang
authors.affiliation: Department of Medical Oncology, General Hospital of Ningxia Medical University, Yinchuan, 750004, China.
authors.forename: Xiang-Jiang
authors.initials: XJ
authors.lastname: Luo
authors.affiliation: Department of Medical Oncology, General Hospital of Ningxia Medical University, Yinchuan, 750004, China.
authors.forename: Ning-Ju
authors.initials: NJ
authors.lastname: Wang
authors.affiliation: Department of Medical Oncology, General Hospital of Ningxia Medical University, Yinchuan, 750004, China.
authors.forename: Ping
authors.initials: P
authors.lastname: Chen
authors.affiliation: School of Nursing, Ningxia Medical University, 1160 Sheng Li Street, Yinchuan, 750004, China.|Department of Nursing, Ningxia People's Hospital, 301 Zheng Yuan Street, Yinchuan, 750004, China.
authors.forename: Xin
authors.initials: X
authors.lastname: Jin
authors.affiliation: School of Nursing, Ningxia Medical University, 1160 Sheng Li Street, Yinchuan, 750004, China.
authors.forename: Guo-Xia
authors.initials: GX
authors.lastname: Mu
authors.affiliation: School of Nursing, Ningxia Medical University, 1160 Sheng Li Street, Yinchuan, 750004, China.
authors.forename: Xiao-Min
authors.initials: XM
authors.lastname: Chai
authors.affiliation: Department of Medical Oncology, General Hospital of Ningxia Medical University, Yinchuan, 750004, China.
authors.forename: Yue-Juan
authors.initials: YJ
authors.lastname: Zhang
authors.affiliation: School of Nursing, Ningxia Medical University, 1160 Sheng Li Street, Yinchuan, 750004, China. li_yuxiang@163.com.
authors.forename: Yu-Xiang
authors.initials: YX
authors.lastname: Li
authors.affiliation: Department of Pharmacology, Pharmaceutical Institute of Ningxia Medical University, 1160 Sheng Li Street, Yinchuan, 750004, China. yujq910315@163.com.
authors.forename: Jian-Qiang
authors.initials: JQ
authors.lastname: Yu
mesh_terms: D000280:Administration, Inhalation; D000700:Analgesics / Q000008:administration & dosage* / Q000009:adverse effects; D059390:Breakthrough Pain / Q000175:diagnosis / Q000188:drug therapy* / Q000209:etiology; D002681:China; D002985:Clinical Protocols; D004311:Double-Blind Method; D006801:Humans; D009369:Neoplasms / Q000150:complications* / Q000175:diagnosis; D009609:Nitrous Oxide / Q000008:administration & dosage* / Q000009:adverse effects; D010102:Oxygen Inhalation Therapy / Q000009:adverse effects; D010147:Pain Measurement; D017060:Patient Satisfaction; D011788:Quality of Life; D012107:Research Design; D011795:Surveys and Questionnaires; D013997:Time Factors; D016896:Treatment Outcome
chemical_list: D000700:Analgesics; D009609:Nitrous Oxide
keywords: Analgesia; Breakthrough pain; Cancer patients; Nitrous oxide