The use of pre-cannulation local anaesthetic and factors affecting pain perception in the emergency department setting

Study objective-To determine whether the use of subcutaneous local anaesthe tic (lignocaine) is associated with a reduction in cannulation pain in the emergency department setting. Methods-Patients over 18 with a Glasgow Coma Score (GCS) of 15 and conversa tional English were allocated into one of three groups: Group 1 were cannul ated after routine skin preparation; Group 2 received 1% lignocaine 0.1 mi via a 27 gauge needle and diabetic syringe before cannulation; Group 3 were injected as for Group 2 but saline was substituted for lignocaine. The can nulator and subject were blinded to the ampoule. The pain was measured usin g a 100 mm visual analogue scale. Setting-A large urban university hospital emergency department. Results-366 patients were recruited and the data on 322 analysed. Those rec eiving lignocaine before cannulation reported lower pain scores (1.9 cm) th an the saline (4.1 cm) or immediate cannulation (3.6 cm) groups, p <0.0001. Other factors such as the experience of cannulator, patient characteristic s, the presence of a painful underlying condition and cannula size did not effect pain scores. Conclusion-The use of lignocaine before cannulation reduced cannulation pai n in the emergency department setting. Other factors examined did not influ ence pain perception.