Nitrous Oxide for Early Analgesia in the Emergency Setting: A Randomized, Double‐blind Multicenter Prehospital Trial. (13th February 2013)

• Record Type: Journal Article
• Authors: Ducassé, Jean‐Louis; Siksik, Georges; Durand‐Béchu, Manon; Couarraze, Sébastien; Vallé, Baptiste; Lecoules, Nathalie; Marco, Patrice; Lacombe, Thierry; Bounes, Vincent; Miner, James R.
• Is Part Of: Academic emergency medicine. Volume 20:Number 2(2013:Feb.)
• Page Start: 178
• Page End: 184
• Publication Date: 2013-02-13
• Subjects: Emergency medicine -- Periodicals; 616.02505
• DOI: 10.1111/acem.12072
• Languages: English
• ISSNs: 1069-6563

Abstract

<abstract abstract-type="main" xml:lang="en" id="acem12072-abs-0001"> <title>Abstract</title> <sec id="acem12072-sec-0001" sec-type="section"> <title>Objectives</title> <p>Although 50% nitrous oxide (N<sub>2</sub>O) and oxygen is a widely used treatment, its efficacy had never been evaluated in the prehospital setting. The objective of this study was to demonstrate the efficacy of premixed N<sub>2</sub>O and oxygen in patients with out‐of‐hospital moderate traumatic acute pain.</p> </sec> <sec id="acem12072-sec-0002" sec-type="section"> <title>Methods</title> <p>This prospective, randomized, multicenter, double‐blind trial enrolled patients with acute moderate pain (numeric rating scale [NRS] score between 4 and 6 out of 10) caused by trauma. Patients were assigned to receive either 50/50 N<sub>2</sub>O and oxygen 9 L/min (N<sub>2</sub>O group) or medical air (MA) 9 L/min (MA group), in ambulances from two nurse‐staffed fire department centers. After the first 15 minutes, every patient received N<sub>2</sub>O and oxygen. The primary endpoint was pain relief at 15 minutes (T15), defined as a NRS ≤ 3 of 10. The NRS was measured every 5 minutes. Secondary endpoints were treatment safety and adverse events, time to analgesia, and patient and investigator satisfaction with analgesia.</p> </sec> <sec id="acem12072-sec-0003" sec-type="section"> <title>Results</title> <p>Sixty patients were included with no differences between groups in age (median = 34 years, interquartile range [IQR] = 23 to 53 years), sex (37 males, 66%), and initial median NRS of 6 (IQR = 5 to 6). At T15, 67% of the patients in the N<sub>2</sub>O group had an NRS score of 3 or lower versus 27% of those in the MA group (delta = 40%, 95% confidence interval [CI] = 17% to 63%; p < 0.001). The median pain scores were lower in the N<sub>2</sub>O group at T15, 2 (IQR = 1 to 4) versus 5 (IQR = 3 to 6). There was a difference at 5 minutes that persisted at all subsequent time points. Four patients (one in the N<sub>2</sub>O group) experienced adverse events (nausea) during the protocol.</p> </sec> <sec id="acem12072-sec-0004" sec-type="section"> <title>Conclusions</title> <p>This study demonstrates the efficacy of N<sub>2</sub>O for the treatment of pain from acute trauma in adults in the prehospital setting.</p> </sec> </abstract>