Mitigation of pain during intravenous catheter placement using a topical skin coolant in the emergency department

Objective: Although intravenous (IV) line placement is a common procedure in the emergency department (ED), it is an uncomfortable experience for many patients. Topical analgesic agents are rarely used because they have long onsets of action and thereby cause unacceptable treatment delays. Cryoanaesthesia, the use of cooling agents to reduce pain, has been recognised for many years as a potential pain management strategy. The purpose of this study was to determine whether an instantaneous topical skin coolant spray reduces patient's pain during IV cannulation and represents a feasible alternative for cutaneous analgesia in the ED setting. Methods: We conducted an unblinded, randomised, controlled study, in a convenience sample of ED patients. Utilising a random number generator to assign patients to the control or study group, patients over the age of 18 years who required IV cannulation as part of their evaluation were enrolled at two tertiary care hospitals. In both groups, IV lines were placed in accordance with accepted clinical standards of practice, with the single addition of the coolant spray delivered to the IV site before needle insertion in the study group. All study participants answered questionnaires before and after IV placement and rated pain during procedure on a 100 mm visual analogue scale. Results: Of the 92 patients enrolled in the study, 47 (51.1%) were randomised to the study group and received the anaesthetic spray, and 45 (48.9%) were randomised to the control group and had their IV placed in a standard method. 66 patients were female (71.8%) and 26 (28.2%) were males. The mean pain score in the study group was 27 mm (95% confidence interval (CI) 19.9 to 34.1 mm) and 28 mm (95% CI 20.4 to 35.6 m) in the control group (p = 0.934). Subgroup analysis of female and male patients did not show significance. Conclusions: Our study failed to detect a difference in pain perception resulting from the pre-procedural application of a skin coolant associated with IV placement in the ED setting.