Warming lignocaine to reduce pain associated with injection
Related Experiment Videos
1Department of Anaesthesia, Western Infirmary, Glasgow.
Objective:
To investigate the effect of warming lignocaine on the pain associated with subcutaneous injection.
Design:
Double blind, randomised, crossover study.
Setting:
Hospital clinic.
Subjects:
40 healthy volunteers.
Interventions:
Subcutaneous injection with 1 ml of 1% lignocaine at 20 degrees C and 1 ml of 1% lignocaine at 37 degrees C.
Main Outcome Measures:
Pain assessed by linear analogue pain scores and subjects' comparison of pain on injection.
Results:
25 subjects (89%; 95% confidence interval 72% to 98%) thought that lignocaine at 20 degrees C was more painful and 3 (11%; 2% to 28%) thought that lignocaine at 37 degrees C was more painful (p < 0.0001); 12 subjects did not express a difference. Median pain score for injection at 20 degrees C was 11.00 and at 37 degrees C was 3.25 (p < 0.001). Median difference was 8.25 (4.00 to 13.50).
Conclusions:
The simple procedure of warming to 37 degrees C reduced the pain associated with subcutaneous injection of lignocaine.