Entonox® inhalation to reduce pain in common diagnostic and therapeutic outpatient urological procedures: a review of the evidence

Abstract

INTRODUCTION Entonox® (50% nitrous oxide and 50% oxygen; BOC Healthcare, Manchester, UK) is an analgesic and anxiolytic agent that is used to successfully reduce pain and anxiety during dental, paediatric and emergency department procedures. In this article we review the application and efficacy of Entonox® in painful local anaesthesia urological procedures by performing a systematic review of the literature. METHODS A MEDLINE® search was performed using the terms ‘nitrous oxide’, ‘Entonox’, ‘prostate biopsy’, ‘flexible cystoscopy’ and ‘extracorporeal shock wave lithotripsy’. English language publications of randomised studies were identified and reviewed. RESULTS The search yielded five randomised studies that investigated the clinical efficacy of Entonox® as an analgesic for day case urological procedures. Three randomised controlled trials (RCTs) investigated Entonox® in transrectal ultrasonography guided prostate biopsy. All three reported significant reductions in pain score in the Entonox® versus control groups. One RCT reported significant reduction in pain during male flexible cystoscopy in the Entonox® group compared with the control group. One RCT, which examined the use of Entonox® during extracorporeal shock wave lithotripsy, found its use significantly decreased the pain score compared with the control group and this was comparable to intravenous pethidine. CONCLUSIONS Evidence from varied adult and paediatric procedures has shown Entonox® to be an effective, safe and patient acceptable form of analgesia. All published studies of its use in urological day case procedures have found it to significantly reduce procedural pain. There is huge potential to use this cheap, safe, effective analgesic in our current practice.

Care‐related pain in hospitalized patients: Severity and patient perception of management

“…Nevertheless, in our hospital, the rates of information delivery and treatment proposition and delivery were still insufficient despite the existence of preventive treatments and protocols such as the use of local anaesthetics and inhalation agents (nitrous oxide) for some procedures. The 50% mixture of nitrous oxide and oxygen is not sufficiently well known or used for CRP relief, although indications and protocols are well established for many procedures such as changing dressings, haematological painful procedures, urodynamic procedures, colonoscopy and minor surgery (Annequin et al, 2000;Calleary et al, 2007;Aboumarzouk et al, 2011;Young et al, 2012;Yuxiang et al, 2012). The treatment is efficient and well tolerated even in fragile populations as children or older adults and terminally ill patients (Annequin et al, 2000;Nicolas and Lassauzay, 2009;Reinoso-Barbero et al, 2011) or in the pre-hospital setting in acute trauma in adults (Ducassé et al, 2013).…”

Transcutaneous Electric Nerve Stimulation (TENS) for pain relief during Extracorporeal Shock-Wave Lithotripsy (ESWL)

“…Factors affecting analgesic requirement in ESWL are age, amount of energy, site and size of the stone, and type of lithotripter [17]. The introduction of new models of lithotripters led to conversion of the trend of anesthesia from general and regional anesthesia to sedative analgesic technique [16].…”

Efficacy of preprocedural diclofenac in men undergoing double J stent removal under local anesthesia: A double-blind, randomized control trial

“…[89] Patients receiving entonox had lesser pain scores, however with more complications but transient. Patients receiving air needed significantly more analgesia and general anesthetic if repeat cystoscopy was needed.…”