Lidocaine is an amide local anaesthetic initially used intravenously as an antiarrhythmic agent. At some point it was proposed that intravenous lidocaine (IVL) had an analgesic effect that could be potentially beneficial in perioperative settings. Since these preliminary reports, a large body of evidence confirmed that IVL had anti-inflammatory and opiate-sparing effects, a combination of characteristics leading to an array of effects such as a decrease in postoperative pain and opiate consumption, and a reduction in the duration of digestive ileus. Additional studies demonstrated IVL to possess antithrombotic, antimicrobial and antitumoral effects. Beneficial effects of IVL have been characterized in abdominal surgery but remain controversial in other types of surgeries. Because the quality of evidence was limited, due to inconsistency, imprecision and study quality, recent conclusions from meta-analysis pooling together all types of surgery stated the uncertainty about IVL benefits. Additional indications such as the prevention of propofol-induced injection pain, prevention of hyperalgesia, protection against bronchial reactivity by bronchotracheal relaxation during surgery, and the increase in depth of general anaesthesia have since emerged. IVL is rapidly distributed in the body and metabolized by the liver. With the commonly recommended doses, lidocaine's therapeutic index remains very high and the plasma concentrations stay largely below the cardiotoxic and neurotoxic threshold levels, a notion that may be used by clinicians to draw conclusions on the benefit-risk profile of IVL in comparison to other analgesic strategies. The purpose of this review is to address the pharmacokinetic and pharmacodynamic properties of lidocaine in healthy and pathological conditions.

We have demonstrated that as compared with median-nerve-type motor response, injection performed after a radial-nerve-type motor response promoted reproducible and remarkable ultrasound spread characteristics associated with complete sensory block of the 3 cords at 30 minutes.

The present study showed that the ultrasound approaches were less painful and more comfortable than neurostimulation to place axillary blocks. We also showed that, although pain intensity resulting from blocks placement was similar with the ultrasound approaches, very comfortable procedures were more frequent with the out-of-plane than with the in-plane approach.