Multicenter, triple-blind randomized placebo controlled trial of adjuvant nitrous oxide 50% in oxygen 50%: efficacy for reducing pain and increasing satisfaction in patients treated for renal colic in the emergency department
Aguilar Mulet JM, Álvarez Rodríguez V, Borobia Pérez AM, Velayos Rubio R, Ochoa Mazarro MD, Del Arco Galán C
Affiliation of the authors
Servicio de Urgencias, Hospital Universitario de la Princesa, Instituto de Investigación Sanitaria del Hospital de la Princesa (IIS-IP), Madrid, Spain. Servicio de Urgencias, Hospital Universitaro de Getafe, Madrid, Spain. Servicio de Farmacología Clínica y Servicio de Urgencias, Hospital Universitario de la Paz, IdiPAZ, Plataforma Española de Ensayos Clínicos (SCReN), Madrid, Spain. Servicio de Urgencias, Hospital Universitario Infanta Leonor, Madrid, Spain. Servicio de Farmacología Clínica, Hospital Universitario de la Princesa, Instituto de Investigación Sanitaria del Hospital de la Princesa (IIS-IP), Plataforma Española de Ensayos Clínicos (SCReN), Madrid, Spain.
Aguilar Mulet JM, Álvarez Rodríguez V, Borobia Pérez AM, Velayos Rubio R, Ochoa Mazarro MD, Del Arco Galán C. Multicenter, triple-blind randomized placebo controlled trial of adjuvant nitrous oxide 50% in oxygen 50%: efficacy for reducing pain and increasing satisfaction in patients treated for renal colic in the emergency department. Emergencias. 2016;28:305-12
Summary
Objective.
To assess the efficacy of a nitrous oxide and oxygen mixture (N2O/O2 50/50) for reducing pain and increasing satisfaction in patients with an initial clinical diagnosis of renal colic in the emergency department.
Methods.
Multicenter, triple-blind randomized placebo-controlled trial. We randomized 147 patients with a clinical diagnosis of renal colic to an experimental group to receive the N2O/O2 50/50 mixture (n = 70) or a control group to receive 50% oxygen in air (n = 77). Both groups also received conventional analgesia with dexketoprofen plus
metamizol and opiates administered sequentially until pain was brought under control; rescue doses of opioids were also available. The endpoints were the reduction in pain intensity expressed on a visual analog scale (VAS) 5 minutes after the start of treatment and the patient’s level of satisfaction with treatment on discharge.
Results.
The mean (SD) reduction in pain 5 minutes after starting analgesic treatment was 1.84 (2.05) VAS points in the intervention group and 1.67 (1.91) in the placebo group. The difference was not significant (P = .603). Neither were between-group differences significant at other pain evaluation times (10, 15, 30, and 60 minutes). Treatment was considered satisfactory (
