Adjuvant use of intravenous lidocaine for procedural burn pain relief: a randomized double-blind, placebo-controlled, cross-over trial. Intravenous lidocaine in central pain: a double-blind, placebo-controlled, psychophysical study. Expanding the use of topical anesthesia in wound management: sequential layered application of topical lidocaine with epinephrine. Clinical studies with computer-assisted initial lidocaine therapy. Lidocaine test in neuralgia. A double-blind randomized comparison of lidocaine and saline for cervical anesthesia. Evaluation of lidocaine as an analgesic when added to hypertonic saline for sclerotherapy. Concentration-effect relationship of intravenous lidocaine on the allodynia of complex regional pain syndrome types I and II. A randomized controlled trial of intracameral lidocaine during phacoemulsification under topical anesthesia.
Pain is a major issue for patients with severe burn. High dose intravenous opioids form the mainstay of procedural burns pain management; however it was suggested that intravenous lidocaine assists with minimising the pain experience. This study aimed to evaluate whether intravenous lidocaine improved analgesic efficacy and decreased opioid consumption during a burn wound care procedure.
                A prospective double-blind randomized crossover study compared intravenous lidocaine versus placebo alongside patient controlled analgesia (PCA) in 45 patients with severe burn undergoing wound care procedures (i.e. dressing change±debridement) on two consecutive days. Subjects were randomised to either the intervention or control condition on the first dressing day, and received the alternate condition on the second dressing day. During the intervention condition, subjects received lidocaine of 1.5 mg/kg/body weight followed by two boluses of 0.5 mg/kg at 5-min intervals followed by a continuous infusion. During the control condition, 0.9% sodium chloride was administered at an equivalent volume, dose and rate to that of lidocaine. Primary end points included pain intensity as measured by verbal rating scale (VRS), time to rescue analgesia, opioid requests and consumption and overall anxiety and level of satisfaction.
                Changes in the VRS score was significantly lower for lidocaine [difference (95% CI)=0.36 (0.17-0.55)] as compared to placebo. However, there were no significant clinical or statistical differences regarding the effects of lidocaine and placebo on opioid requests and consumption, anxiety or level of satisfaction during the first and second dressing procedures.
                In this study, the clinical benefit of intravenous lidocaine for pain relief during burn wound dressing changes in terms of overall pain scores and opioid consumption was unremarkable. Further investigations using different lidocaine regimes for the management of procedural burn pain are warranted.
                Copyright © 2011 Elsevier Ltd and ISBI. All rights reserved. To investigate the effects of systemic administration of lidocaine on different components of neuropathic central pains by quantitative sensory testing.
                The efficacy of systemic lidocaine (5 mg/kg IV over 30 minutes) was evaluated in a double-blind, placebo-controlled, and cross-over fashion, on both spontaneous ongoing pain and evoked pains (allodynia and hyperalgesia) in 16 patients with chronic poststroke (n = 6) or spinal cord injury (n = 10) related pain.
                Lidocaine was significantly superior to the placebo (saline) in reducing the intensity of spontaneous ongoing pain for up to 45 minutes after the injection: 10 of 16 patients (62.5%) receiving lidocaine showed a significant reduction in spontaneous pain, whereas only six patients showed this after the placebo. Lidocaine also significantly reduced the intensity of brush-induced allodynia and mechanical hyperalgesia, but was no better than the placebo against thermal allodynia and hyperalgesia. In general, the side effects were moderate and consisted mainly of lightheadedness (44%).
                Systemic lidocaine can induce a significant and selective reduction of several components of pain caused by CNS injuries. The observed preferential antihyperalgesic and antiallodynic effects of this drug suggest a selective central action on the mechanisms underlying these evoked pains. Topical anesthesia eliminates the need for injection of anesthetic. Most studies on the use of topical anesthesia were done on children, using 3 active ingredients (lidocaine, epinephrine, tetracaine, or tetracaine, adrenaline, cocaine) for relatively small wounds of the face and scalp.
                To demonstrate that topical anesthesia is effective and safe in adults of all ages and for larger wounds, using a preparation with 2 active ingredients, topical lidocaine and epinephrine (TLE).
                One hundred patients were enrolled in a randomized controlled trial, with 50 in each group. The study group received TLE using a unique method of "sequential layered application." The control group received 2% lidocaine infiltration anesthesia. Patients rated the pain from the application of anesthesia and from suturing, using a 0 to 10 visual analog pain scale. Follow-up interviews were conducted to assess for complications and to rate patients' wound repair experience.
                Patients in the study group reported significantly less pain from TLE application, with 66% reporting no pain vs 0% reporting no pain from the infiltration in the control group (P < .001). There was no difference in pain during wound repair between the 2 groups (P approximately .59). On follow-up, 95% of patients contacted in the TLE group rated their experience in regard to pain as "excellent," compared to 5% of patients in the control group (P < .001).
                Topical lidocaine and epinephrine "sequential layered application" is an effective, safe, and less painful method of anesthesia for a wide variety of lacerations. Patients recall their experience with this technique very favorably. A randomized prospective study compared achievement and maintenance of therapeutic plasma concentrations in patients receiving computer-assisted (CA) initial lidocaine hydrochloride therapy, designed pharmacokinetically to achieve and maintain a chosen plasma concentration, v conventional lidocaine therapy (CT). A separate audit of outcome was also conducted. The CA regimens provided more effective concentrations in the first hour than did CT, 2.65 v 1.5 micrograms/mL average. In the audit, ventricular fibrillation occurred in two of 78 CA v eight of 78 CT patients. Dosage adjustments were required in two CA patients v 33 CT patients. The CA therapy improved therapeutic precision, reduced dosage adjustments, and may have improved safety during initial lidocaine therapy before fitting to plasma concentration data for subsequent feedback. An improved clinical computer program now also fits to plasma concentration data. It is accessed and used routinely by hospitals over an international time-sharing network. Ten patients with organic nerve injury causing chronic neuropathic pain were tested for the effects of intravenous lidocaine versus saline upon psychophysical somatosensory variables. The variables assessed were the subjective magnitude of pain, area of mechanical hyperalgesia and presence and magnitude of thermal heat/cold hyperalgesia. The study methods applied to evaluate these conditions were the conventional testing of somatosensory submodalities with area mapping and the subjective magnitude estimation of spontaneous pain. It was found that spontaneous pain and mechanical hyperalgesia were consistently improved, transiently, by intravenous administration of lidocaine in all 10 patients; areas of hyperalgesia which extended beyond the territory of the nerve also improved transiently. Spontaneous pain and mechanical hyperalgesia, but not hypoesthesia, were transiently improved by injection of saline in only 1 of the 10 patients. This outcome is probably due to a placebo effect. This improvement is in keeping with the inhibition of anomalous neural impulses which can be generated anywhere along the sensory channels responsible for generating spontaneous pain and hyperalgesia. Thus, intravenous lidocaine is proposed as a diagnostic aid in the examination of patients complaining of complex sensory disorders associated with nerve injury. The transient pain relief may allow a fuller identification of the area of sensory loss. To compare bacteriostatic saline and buffered lidocaine for cervical anesthesia to blunt the reported pain during brief suction curettage.
                A double-blind randomized clinical trial was conducted on women presenting for pregnancy termination procedures. Participants received either paracervical submucosal injections of bacteriostatic saline or 1% buffered lidocaine just before cervical dilation. Self-reported pain intensity was assessed at three time points during and 30 minutes after the procedure.
                Fifty-two of 135 eligible women presenting for pregnancy termination procedures participated in the study. Pain intensity ratings in lidocaine and saline treatment subjects did not differ significantly at any point. Our study had a power of 0.94 to detect more than a 15% difference on the 21-point box scale between the two solutions. Only one patient requested her block be repeated, and she had received lidocaine originally. Furthermore, of those women receiving lidocaine, 11% reported mild toxicity symptoms.
                To minimize lidocaine toxicity for a brief suction curettage procedure, bacteriostatic saline or very dilute lidocaine could be considered for the paracervical injection solution. The local anesthetic mechanism may be distention rather than blockage of specific autonomic nerves when there is no waiting period. This would mean that the term paracervical block could be changed to cervical anesthesia. The efficacy of sclerosing agents for the treatment of telangiectasias and reticular veins is well established. The injection of these agents is often associated with pain, and it is not uncommon for sclerotherapists to include lidocaine with the sclerosants in an attempt to reduce the pain associated with treatment. However, there are concerns that this may reduce the overall efficacy of the treatment because of dilution of the sclerosant. Patient comfort and overall outcome associated with treatment using HS with lidocaine (LIDO) versus that using HS alone was compared.
                Forty-two patients were prospectively entered into the study and randomized blindly to sclerotherapy with 23.4% HS or 19% LIDO. Study subjects and treating physicians were blinded to the injection solution used. Injection sites were chosen for veins ranging in size from 0.1 to 3 mm. Photographs of the area to be treated were taken, and the patients rated their pain. They were then observed at regular intervals for four months, and clinical data was collected. Thirty-five subjects completed the full follow-up period, and photographs of the injected area were taken again. Three investigators blinded to the treatment assignment then evaluated the photographs and scored the treatment efficacy according to a standardized system.
                In the HS group, 61.9% (13 of 21) patients rated their pain as none or mild, whereas 90.5% (19 of 21) of patients in the LIDO group had no or mild discomfort. This difference is significant, with a P value of.034. There was no difference in the overall efficacy of treatment between the two groups. The groups had similar rates of vein thrombosis and skin necrosis.
                Although lidocaine is often used with sclerosing agents, there are no previous reports in the literature to evaluate its effectiveness in reducing the pain experienced by the patient. In this study, patients receiving LIDO experienced significantly less discomfort at the time of injection than patients who received HS alone. There were no differences in the effectiveness of treatment or in the incidence of complications between the two groups. Several lines of evidence suggest that neuropathic pain (including Complex Regional Pain Syndrome [CRPS] I and CRPS II) is mediated in part by an increase in the density of voltage-sensitive sodium channels in injured axons and the dorsal root ganglion of injured axons. This study sought to characterize the effects of intravenous lidocaine (a sodium channel blocker) on acute sensory thresholds within the painful area and the size of the painful area in patients suffering from CRPS I and II.
                This study used a randomized, double-blind, placebo-controlled design in 16 subjects suffering from CRPS I and II with a prominent allodynia. Each subject received an intravenous infusion of lidocaine and diphenhydramine separated by 1 week. A computer-controlled infusion pump targeted stair-step increases in plasma levels of lidocaine of 1, 2, and 3 microg/ml. At baseline and at each plasma level, spontaneous and evoked pain scores and neurosensory testing within the painful area were measured. The neurosensory testing consisted of thermal thresholds, tactile thresholds and the area of allodynia to punctate, and stroking and thermal stimuli.
                Intravenous lidocaine and diphenhydramine had no significant effect on the cool, warm, or cold pain thresholds. However, lidocaine caused a significant elevation of the hot pain thresholds in the painful area. Intravenous lidocaine caused a significantly decreased response to stroking and cool stimuli in the allodynic area. There was also a significant decrease in pain scores to cool stimuli at all plasma levels and the spontaneous pain at the highest plasma level.
                This study demonstrates that intravenous lidocaine affects pain in response to cool stimuli more than mechanical pain in subjects with neuropathic pain. There is a lesser effect on spontaneous pain and pain induced by stroking stimuli and no effect on the pain induced by punctate stimuli. To test the hypothesis that adjunctive intracameral 1% lidocaine reduces intraoperative pain during phacoemulsification using topical anesthesia.
                Prospective, double-masked, randomized, controlled trial.
                A total of 200 patients undergoing routine phacoemulsification under topical 1% tetracaine were studied.
                Randomization to 0.5 ml intracameral, unpreserved, epinephrine-free 1% lidocaine or placebo was conducted.
                Intraoperative pain was quantified by the patients using a 0-10 visual analog pain scale.
                Intraoperative pain scores (+/- standard deviation) for the lidocaine and control groups were 1.29 +/-1.24 and 1.44 +/- 1.33, respectively (P > 0.35).
                In a rigorously double-masked, prospective, randomized, controlled trial there was no significant reduction in intraoperative pain when intracameral 1% lidocaine was used during phacoemulsification under topical anesthesia.
As current clinical evidence is based on only one single RCT as well as case series and reports, intravenous lidocaine must be considered a pharmacological agent under investigation in burns care, the effectiveness of which is yet to be determined with further well-designed and conducted clinical trials.