A Prospective Clinical Trial Comparing Self-Administered Nitrous Oxide and Haematoma Block for Analgesia in Reducing Fracture of the Distal Radius in an Emergency Department

Abstract

Objective To compare the effectiveness and efficacy of self-administered nitrous oxide and haematoma block in pain relief during close reduction of fractured distal radius in adult patients. Methods This was a prospective clinical trial. All adult patients aged 18 years or above with fracture of the distal radius within 24 hours requiring close reduction in the Accident and Emergency Department of Kwong Wah Hospital were included. Patients with known contraindications were excluded. A consecutive series of patients were randomised into the two groups in alternating fashion. Pain perception (VAS score), procedure time, patient acceptance and complications were measured and monitored. Results A total of 67 patients (53 females and 14 males) with age ranging from 26 to 94 years were enrolled during the period from April 2008 to December 2008; 33 patients received Entonox and 34 received haematoma block. The average VAS score before reduction was 6.97 cm for the Entonox group and 6.76 cm for the haematoma block group (p=0.61). The average VAS score during reduction was 7.19 cm for the Entonox group and 2.80 cm for the haematoma block group (p<0.0001). For the difference of average VAS scores during and before reduction, there was 0.22 cm increase in the Entonox group and 3.95 cm decrease in the haematoma block group (p<0.0001). The relative change of mean VAS score was 3% increase in the Entonox group and 58% decrease in the haematoma block group (p<0.0001). The average procedure time was 6.29 min for the Entonox group and 6.44 min for the haematoma block group (p=1). In the Entonox group, 64% patients agreed to use the same analgesia method under similar circumstances whereas in the haematoma block group, it was 91% (p=0.009). There were no complications or failed reductions in both groups. Conclusion Haematoma block is a safe and effective analgesia in the reduction of fractured distal radius with less pain perception, more patient acceptance and similar procedure time compared with Entonox.