| ||||||||||||||
|
|
|||||||||||||

From the *Department of Anaesthesia, Guy's & St. Thomas' NHS Foundation Trust, London, UK; and
Department of Anaesthesia, St Richard's Hospital, Royal West Sussex NHS Trust, Chichester, UK.
Address correspondence and reprint requests to Teodor Goroszeniuk, FCA RCSI, Department of Anaesthesia, Guy's Hospital, Guy's & St. Thomas' NHS Foundation Trust, St. Thomas St., London SE1 9RT, UK. Address e-mail to teogoroszeniuk{at}doctors.org.uk.
Abstract
BACKGROUND: The addition of clonidine to local anesthesia prolongs the local anesthetic action, but in humans, the contribution of a peripheral mechanism remains unclear.
METHODS: We investigated clonidine's peripheral effect in 20 healthy volunteers undergoing double-blind, subcutaneous infiltration of 0.5% lidocaine with normal saline to one forearm and then, immediately, of lidocaine with 10 µg clonidine to the contralateral arm. Pinprick sensation was tested every 15 min for 6 h.
RESULTS: Median time to return of normal sensation was 3.5 h for lidocaine alone, but at least 6 h if combined with clonidine (P < 0.001).
CONCLUSIONS: Clonidine has a significant peripheral action in enhancing duration of local anesthesia on superficial co-infiltration with lidocaine.
|