Local infiltration of lidocaine versus lidocaine iontophoresis in pain relief during radial artery cannulation for open heart surgery

ABSTRACT

Traditionally, pain has been thought to be an unfortunate but inevitable part of disease and its treatment. Pain associated with medical procedures was ignored because it was thought to be unavoidable. The question of why physicians should treat pain is as important as the knowledge of preventing it, since it is a right measure to take. This study was conducted to compare the effectiveness of lidocaine iontophoresis with that of local infiltration of lidocaine for the prevention and reduction of pain during radial artery cannulation, in patients undergoing open heart surgery. The present study comprised 60 adult patients, 36 males and 24 females, aged from 29 to 84 years with a median age of 63.8 [ +/- 10.35 SD] and 65.4 [10.48 +/- SD] for groups 1 and 2, respectively. The patients underwent elective open-heart surgery in Nemazee Hospital affiliated to Shiraz University of Medical Sciences. Prior to induction of general anesthesia, patients were randomly allocated to one of two groups for analgesia prior to radial artery cannulation on an alternate week basis. Group 1 [n=30] patients received one-week analgesia using lidocaine iontophoresis, and analgesia in Group 2 [n=30] was performed using lidocaine infiltration the following week. Both groups were similar in terms of gender distribution. The VAS scores in group 1 were significantly lower than group 2 with no significant difference in the difficulty of cannulations between the two groups. There was no complaint of pain from patients during iontophoresis, and no report of any significant side effects. Slight skin erythma was noted after removal of the iontophoretic anode patch in 4 patients, which lasted for about 0.5-4 hours. This study has demonstrated that lidocaine iontophoresis is a useful, non-invasive, rapid, painless alternative to lidocaine infiltration for dermal analgesia for radial artery cannulation