The Phonophoresis of Lidocaine Gel and Its Effect on Sensory Blockage

Effect of Lidocaine Phonophoresis on Sensory Blockade: Pulsed or Continuous Mode of Therapeutic Ultrasound?

The optimisation of drug absorption through skin is of great value in modern therapy.Phonophoresis is the use of therapeutic ultrasound to increase percutaneous drug absorption. However,few studies have compared pulsed and continuous modes of therapeutic ultrasound.This study compared these two modes by investigating the effect of lidocaine phonophoresis on sensory blockade. Ninety-three healthy volunteers, assigned at random to one of three ultrasound groups:pulsed(ultrasound+lidocaine),continuous(ultrasound+lidocaine)and control(sham ultrasound+lidocaine). Lidocaine was administered transdermally using a transducer.Two point discrimination, touch and maximum pain thresholds were assessed before and after the intervention in each group. Pulsed ultrasound with topical lidocaine gel induced greater anaesthetic effect compared with continuous ultrasound with topical lidocaine gel and lidocaine application alone. The mechanical properties of pulsed ultrasound appear to be responsible for greater drug penetration.

Lidocaine is a common local anaesthetic drug that is used topically to relieve pain,itching and burning, and also for minor surgery.However,its application via this conductive method,has been confined to surface anaesthesia because it seems that it is not possible to have a deep transmission with local drug massage, without injection or systematic administration.On the other hand,the injection of lidocaine can lead to tissue injury and pain,and its use is not advised in children. Phonophoresis is one of the common procedures for reducing these problems. Therefore, the main aim of this study was to compare the two modes of therapeutic ultrasound by assessing the effect of lidocaine gel phonophoresis on percutaneous absorption and sensory blockade.

Lidocaine (approximately 2 cc) was administered transdermally using a transducer (continuous ultrasound )

Inclusion Criteria: Men and women aged 18 to 25 years Exclusion Criteria: individuals who had a disease that could affect the experiment, such as systemic disease,impairment of the sensory system(e.g.neuropathy,diabetes),cardiovascular disorders(e.g. increased blood pressure),pain due to an injury to the upper extremity,tumours,malignant and precancerous tissue,acute infection and broken skin in the area; and individuals taking medication to relieve disease symptoms were excluded

Ebrahimi S, Abbasnia K, Motealleh A, Kooroshfard N, Kamali F, Ghaffarinezhad F. Effect of lidocaine phonophoresis on sensory blockade: pulsed or continuous mode of therapeutic ultrasound? Physiotherapy. 2012 Mar;98(1):57-63. doi: 10.1016/j.physio.2011.01.009.