Subcutaneous injection of lidocaine around ischemic ankle provides safe and effective foot analgesia in patients with critical limb ischemia.

OBJECTIVE: It is often difficult to alleviate foot pain associated with critical limb ischemia (CLI) using common analgesics. Neuraxial block is contraindicated in anticoagulant therapy. This study was designed to determine the response to subcutaneous injection of lidocaine around the network of peripheral nerves around the ankle in patients with CLI pain on anticoagulants and antiplatelets. METHODS: Sixteen patients with CLI pain in the foot were enrolled in this double-blind placebo-controlled crossover study. Patients were randomized to receive either 2% lidocaine or saline via catheters inserted into the subcutaneous area around the ankle. After recurrence of pain, the patients were crossed over to receive the alternative treatment. Pain was assessed with a numerical rating scale (NRS) before and 15 min after injection. Patients used a descriptive scale to grade pain control and were asked to determine the duration of analgesia in each arm of the study. RESULTS: No serious complications including protracted bleeding occurred. Lidocaine significantly decreased the NRS on movement from 10 (6, 10) [median (range)] to 2 (0, 10) (p < .001), and the differences in the Δ change in NRS between lidocaine and placebo were significant (p = .009). Of the 16 patients, 14 patients were very satisfied after lidocaine but only one described the same after saline. The effect of lidocaine and placebo lasted 11 (0, 28) and 1 (0, 22) h, respectively. CONCLUSION: Subcutaneous injection of lidocaine around the ischemic ankle affectively alleviated pain in patients with CLI without serious adverse effects under anticoagulant therapy.

Asenapine versus olanzapine for the treatment of nausea and vomiting in patients with cancer: A retrospective study.

AIM: Patients with cancer often experience nausea and vomiting (N/V), but may have difficulty using olanzapine (OLZ), a common antiemetic. Asenapine (ASE) is a multi-acting receptor-targeted antipsychotic like OLZ, although there is little evidence that ASE serves as an antiemetic. The aim of this study was to evaluate the efficacy and tolerability of ASE compared to those of OLZ for the treatment of N/V in patients with cancer. METHODS: This retrospective study involved patients who received 5 mg ASE, 5 mg OLZ, or 2.5 mg OLZ for 2 days. Daily worst N/V was rated on a scale of 0 (none) to 3 (very much). The primary endpoint was the proportion of patients who had a response, defined as any reduction in N/V score. A complete response (CR) was defined as a score reduction to 0. Secondary endpoints included the proportion of patients with CR and adverse events. RESULTS: Between April 2017 and March 2023, 212 patients were enrolled to receive treatment: 5 mg ASE (n = 34), 5 mg OLZ (n = 102), or 2.5 mg OLZ (n = 76). No significant differences in response rates (52.9% vs. 58.8% vs. 52.6%, p = 0.671) or secondary endpoints were observed between the groups. Patients receiving ASE were more likely to experience oral hypoesthesia (p = 0.004). CONCLUSION: This preliminary study suggests that ASE may be effective for N/V. Further studies are required to confirm these findings.

Case Reports of Transdermal Fentanyl Patch Administration Difficulties in Cancer Patients with Excess Sweating.

(Case 1) A 45-year-old male was diagnosed with prostate cancer. Treatment was administered using bicalutamide and leuprorelin acetate, while a transdermal fentanyl (TDF) was applied for pain relief. However, TDF continued to peel off owing to excessive sweating, even when reinforced by a protective layer. As such, TDF was discontinued and pain control was initiated using other medicines. Sweating occurred irregularly because of hot flashes, approximately four to five times per day. (Case 2) A 37-year-old male was diagnosed with a malignant thymoma and sacral metastasis. For analgesic control, etodolac tablets, carbamazepine tablets, and TDF were administered. Subsequently, the dose of the TDF was gradually increased, but the analgesic effect was low; thus, fentanyl blood concentration was measured. The measurements showed that even higher TDF doses did not increase fentanyl blood levels. During this period, full body sweating began to occur to a large extent due to unknown causes, and it was thought that the absorption of fentanyl decreased. When using a TDF, it is necessary to monitor patients for any sweating during treatment, while also considering changes in medication in some cases. This should promote the maintenance and improvement of the quality of life of the affected patients.

Pharmacokinetic Analysis, Analgesic Effects, and Adverse Effects of Tapentadol in Cancer Patients with Pain.

In this study, we conducted a pharmacokinetic analysis of tapentadol (TP) in Japanese patients with cancer pain and identified covariates influencing pharmacokinetic parameters. In addition, the analgesic effects and adverse effects of TP were investigated. Data were collected from in-patients with cancer pain who had been administered TP as an extended-release formula. The median (range) estimated clearance (CL/F) and distribution volume (Vd/F) of TP were 86.7 (31.3-213.7) L/h and 1288 (189-6736) L, respectively. There was a strong negative correlation between CL/F and age, Child-Pugh score, and albumin-bilirubin (ALBI) score. The subjects were further divided into two groups according to the factors highly correlated with CL/F. The CL/F of patients in the Child-Pugh B group was 0.46-times that of patients in the Child-Pugh A group. In addition, the CL/F of patients with an ALBI score > -2.40 was 0.56-times that of patients with ALBI scores ≤-2.40, and both differences were statistically significant (p < 0.05). The mean intensity of pain over 24 h was investigated daily from before starting TP for the first 7 d of the treatment. TP reduced pain in six of nine patients; the mean pain visual analogue scale score decreased significantly from 59.2 mm before administration to 42.5 mm at days 5-7. Overall, the Child-Pugh and ALBI scores significantly affected the clearance of TP, which was reduced in patients with impaired liver function. These results suggest that TP is an opioid with a sufficient analgesic effect for cancer patients.

Short-term results of intrathecal injection of low-dose bupivacaine in outpatients with chronic low back and lower extremity pain.

PURPOSE: To investigate the safety and efficacy of intrathecal injection as an alternative to epidural injection for analgesia. METHODS: Seventy consecutive outpatients with chronic low back and lower extremity pain received lumbar intrathecal injection of low-dose isobaric bupivacaine using a 25-gauge pencil-point needle. The patients received 0.5, 1.0, and 1.5 mg of bupivacaine at 1-week intervals to determine the optimal dose. Thereafter, they received two more weekly injections with the optimal dose. The safety and efficacy of the treatment were assessed over a 1-year period. RESULTS: No serious adverse events were encountered. The optimal dose of bupivacaine (1.0 mg in 60% of patients) alleviated pain and disability (both, p < 0.0001) and provided anesthesia below L1 (L5-T6). Motor block was negligible, and balance impairment improved relative to baseline (p < 0.0001). CONCLUSION: Intrathecal injection of low-dose bupivacaine offers a safe and effective treatment for chronic low back and lower extremity pain. TRIAL REGISTRATION: The study was approved by the Kitasato University Hospital Ethics Committee, and written informed consent was obtained from all individual participants included in the study. This trial was registered with the University Hospital Medical Information Network (UMIN000008670). These slides can be retrieved under electronic supplementary material.

The Initial Subjective Sensory Change in the Dermatome During Intrathecal Injection of Plain Bupivacaine Predicts the Spread of Sensory Blockade: A Prospective Multi-Level Modeling Study.

BACKGROUND: Predicting the spread of anesthesia after intrathecal injection of plain local anesthetics is challenging owing to both patient and anesthesiologist-related factors. OBJECTIVES: This study aimed to examine the initial patient-reported sensory changes during intrathecal injections and used multi-level analyses to examine the relationships between these changes and other major factors affecting the spread of anesthesia. METHODS: The participants were 120 consecutive patients with the American Society of Anesthesiologists status I and II, who were scheduled for open repair of inguinal hernias under spinal anesthesia. Lumbar puncture was performed at the midline of the L3 - L4 vertebrae and 3 mL of 0.5% isobaric bupivacaine was administered at 0.25 mL/s. The onset, dermatome, and side of the initial subjective sensory changes (ISSCs) were assessed by patient report. The extent of sensory loss to ice and pinprick stimuli, the degree of motor block in lower extremities, blood pressure, and heart rate were examined at 5-minutes intervals for 20 minutes after intrathecal injection. RESULTS: All patients reported ISSCs after 9 (4, 18) seconds [median (minimum, maximum)] of the intrathecal injection onset. In 66.7% of the patients, ISSCs occurred in the L1 - L5 dermatomes. Three patients experienced pain during the early intraoperative period, and described ISSCs in the sacral dermatome. Height, mean blood pressure, and ISSCs were significantly correlated with sensory loss. Faster onset, lower dermatome, and floor-side of ISSCs predicted a narrower area of sensory loss, with dermatome as the most important indicator. CONCLUSIONS: Our findings demonstrate that ISSC, primarily based on dermatome, is a significant predictor for spinal anesthesia spread.

[Clinical Effects of Opioid Switching to Tapentadol - Retrospective Analysis of Efficacy and Adverse Effects].

The objective of our study was to evaluate the efficacy and adverse effects of opioid switching to tapentadol(TP). It was a retrospective survey carried out at the Kitasato University Hospital outpatient clinic between September 2014 and May 2016. We evaluated pain intensity using the visual analogue scale and the occurrence of adverse effects before switching, at the first evaluation after switching, and during the steady state of TP administration. We included 10 patients; of these, 3 patients discontinued TP owing to uncontrolled pain. The conversion ratio of the previously administered opioids to TP was 1.17 at the time of the first evaluation after switching and 1.42 during the steady state. The mean(±SD)pain intensity was 4.2±2.2 before opioid switching and 4.6±2.2 at the time of the first evaluation after switching. The mean(±SD)pain intensity in the 7 patients excluding the 3 patients who discontinued TP was 4.3±2.0 before opioid switching and 2.7±1.9 during the steady state. Somnolence improved in 5 patients and constipation improved in 2 patients when a stable dose was achieved. Opioid switching to TP was appropriately accomplished using the conversion ratio. Furthermore, pain, sleepiness, and constipation improved following successful titration. These data suggest that TP can be useful in the treatment of cancer pain, in addition to the currently used opioid preparations.

Clinical features and predictors of patients with critical limb ischemia who responded to autologous mononuclear cell transplantation for therapeutic angiogenesis.

The clinical features of patients with critical limb ischemia (CLI) who responded to angiogenesis using autologous peripheral blood mononuclear cell transplantation (PB-MNC) have not yet been fully characterized, and there are no useful predictors to judge the curative effect in the early period after PB-MNC. This study sought to clarify the clinical features and predictors in patients with CLI who were successfully treated using PB-MNC. 30 consecutive patients [arteriosclerosis obliterans: 24 patients, thromboangiitis obliterans: 6 patients] who were diagnosed with major amputation despite maximal medical therapy were enrolled in this study. The study endpoint was major amputation within 3 months after PB-MNC. The collected data were evaluated for correlation between patients with and without major amputation within 3 months after PB-MNC. Six patients underwent major amputation and 1 patient underwent minor amputation. In the patients with major amputation, transcutaneous oxygen tension before PB-MNC and transplanted CD34-positive cells were lower than those of patients without major amputation. In the patients with amputation, interleukin-6 (IL-6) continued to increase after the first PB-MNC, and basic fibroblast growth factor (bFGF) decreased within 3 days after the first PB-MNC. PB-MNC was useful for the patients who were managed for inflammation and who had revascularization of the upper-popliteal arteries and two of the infra-popliteal arteries by endovascular and/or surgical revascularization. Variation in IL-6 and bFGF in the early period after PB-MNC could be useful predictors for the requirement of amputation within 3 months after PB-MNC.

Visual/emotional stimuli and treatment with antidepressants alter Numerical Rating Scale score in patients with chronic pain.

STUDY OBJECTIVE: To examine the impact of visual stimulation (exciting red and tranquilizing green) on the score of the Numerical Rating Scale (NRS) questionnaire in patients with chronic pain. DESIGN: Prospective randomized study. SETTING: Outpatient pain clinic of a university hospital. PATIENTS: Two hundred outpatients with chronic pain. INTERVENTIONS: Patients were randomly assigned to receive the NRS questionnaire printed on either red paper (red group) or green paper (green group). MEASUREMENTS: The questionnaire included 5 questions consisting of the NRS in the worst, in the least, and in the average pain during last week and the NRS at rest and on movement at present. Calculation of the sample size was based on power of 0.8 and α=.01. MAIN RESULTS: The NRS scores were not different between the 2 groups. In patients on antidepressants (n=76) and with depression (n=49), the NRS scores, except the NRS in the worst pain during last week score in patients on antidepressants, were significantly higher in the red group than in the green group (all P≤.040). In the red group, the NRS scores were significantly higher in patients with than without depression (all P≤.003), whereas there was no difference in the scores between patients of the green group with and without depression. CONCLUSION: Our findings suggest that visual/emotional stimuli and treatment with antidepressants alter the NRS score in patients with chronic pain.

Response to intravenous fentanyl infusion predicts subsequent response to transdermal fentanyl.

PURPOSE: Prediction of the response to transdermal fentanyl (FENtd) before its use for chronic pain is desirable. We tested the hypothesis that the response to intravenous fentanyl infusion (FENiv) can predict the response to FENtd, including the analgesic and adverse effects. METHODS: The study subjects were 70 consecutive patients with chronic pain. The response to fentanyl at 0.1 mg diluted in 50 ml of physiological saline and infused over 30 min was tested. This was followed by treatment with FENtd (Durotep MT patch 2.1 mg) at a dose of 12.5 µg/h for 2 weeks. Pain intensity before and after FENiv and 2 weeks after FENtd, and the response to treatment, were assessed by the numerical rating scale (NRS), clinical global impression-improvement scale (CGI-I), satisfaction scale (SS), and adverse effects. RESULTS: The NRS score decreased significantly from 7 (4-9) [median (range)] at baseline to 3 (0-8) after FENiv (p < 0.001), and to 4 (1-8) after FENtd (p < 0.001). The effects of FENiv, as evaluated by ΔNRS, CGI-I, and SS, were significantly greater than those of FENtd (p < 0.001, each), but not by the frequency and the severity of adverse effects, with the exception of dizziness. ΔNRS, and severity of adverse effects (drowsiness, dizziness, nausea, dry mouth, and pruritus) of FENiv correlated significantly with those of FENtd (rs > 0.04, each). CONCLUSIONS: The analgesic and side effects after intravenous fentanyl infusion can be used to predict the response to short-term transdermal treatment with fentanyl.

Immediate analgesic effect of 8% lidocaine applied to the oral mucosa in patients with trigeminal neuralgia.

BACKGROUND: Trigeminal nerve block is widely used for trigeminal neuralgia (TN), though with much painful procedure and potential serious complications. The pain of TN occurs most frequently in the second and the third divisions of the trigeminal nerve, which are distributed in intraoral mucous membrane as well as face skin. Here, we examined the response to intraoral application of 8% lidocaine (LDC) in patients with oral TN pain in a double-blind, placebo (PBO)-controlled crossover study. METHODS: Twenty-four outpatients with oral TN pain were randomized to receive intraoral application of either 8% LDC or saline PBO to the painful area. Following 7-days period, patients were crossed over to receive the alternative treatment. The pain was assessed with a numerical rating scale (NRS) before and 15 minutes after treatment. Patients used a descriptive scale to grade pain outcome and were asked to note any recurrence and the latency for recurrence after therapy. RESULTS: Intraoral LDC, but not PBO, significantly decreased the NRS from 5 (4, 8) (median [25, 75 percentiles]) to 1 (0, 4) (P = 0.001). Of the 24 patients, 19 described marked or moderate relief of pain after LDC but only three described the same after PBO application. The effect of LDC and PBO persisted for 2.8 (0.3, 3.0) and 0 (0, 0) hours, respectively. CONCLUSIONS: Intraoral application of 8% LDC produced prompt analgesia without serious side effects in patients with TN who presented with severe intraoral pain.

[Xenon light therapy].

The xenon light, generated by high-intensity electrical stimulation of xenon gas, is used to sterilize wounds, aid tissue repair, and relieve pain as a low-level light therapy. The light produced consists of non-coherent beams of multiple wavelengths in the ultraviolet to infrared spectrum. This broad-band light can be emitted in a continuous wave or pulsed mode, with the wave band chosen and the energy distribution controlled for the purpose. Specifically, wavelengths in the 500-700 nm range are suitable for treating superficial tissue, and wavelengths between 800 and 1,000 nm are suitable for deeper-seated tissues, due to longer optical penetration distances through tissue. One of the most common benefits in the xenon light therapy is considered to be the wide and deep irradiation of optimal rays to living tissue. Research into the use of xenon light for tissue repair and pain reduction is restricted within open-label studies and case reports. The present review expounded the effects of xenon light therapy on the basis of the available evidence in vitro and in vivo studies using a laser beam of single wavelength.

[Three patients with cervical disc herniation whose severe pain was relieved with oral mini-pulse therapy of betamethasone].

Three patients with severe neck and radicular pain due to cervical disc herniation was not relieved of pain by common drug medication such as NSAIDs and anticonvulsants. Patients underwent oral mini-pulse therapy of betamethasone as the initial dose of 8 mg x day(-1) in the form of 8 tablets of 0.5 mg in a single dose twice a day (after breakfast and after lunch). The daily dose was reduced by half every 4 days, and the therapy was continued for 16 days. In all patients, the pain disappeared completely within the opening 10 days of the therapy, and the pain did not relapse after the therapy. All adverse events of betamethasone including irritation, insomnia and overeating disappeared without medication within several days.

[Continuous intrathecal anesthesia for total hip arthroplasty in a patient with ankylosing spondylitis].

A 73-year-old man suffering from ankylosing spondylitis with limited motion of the whole spine was scheduled for right total hip arthroplasty. Ten years before, the patient had undergone left total hip arthroplasty under general anesthesia, in which epidural anesthesia impossible, intrathecal anesthesia insufficient, and tracheal intubation difficult. In the present operation, an 18 gauge epidural catheter was inserted into the epidural space at L3-4 using paramedian approach. Six ml of contrast medium was administered via the catheter, with high resistance on injection and the spread of epidural contrast medium was limited to L2 and L3. Therefore, the catheter was removed and reinserted into the intrathecal space at L3-4. Two ml of contrast medium demonstrated good spread in the intrathecal space from T12 to S2. Next injection of 0.5% isobaric bupivacaine 2.4ml produced bilateral cold sensory blockade from T10 to S5. Two hours after this injection, a single bolus of 1 ml followed by a continuous infusion at a rate of 0.5 ml x hr(-1) with 0.5% isobaric bupivacaine was commenced. There was no pain at rest and on movement, and no additional analgesics and hypertensive drugs were used until 4 hours following the discontinuation of the continuous intrathecal anesthesia in the morning after the operation. No adverse events including post-dural puncture headache were observed. Continuous intrathecal anesthesia may be effective for total hip arthroplasty in patients with ankylosing spondylitis.

Lidocaine eye drops attenuate pain associated with ophthalmic postherpetic neuralgia.

BACKGROUND: Topical lidocaine (LDC) treatment using a gel or patch preparation is effective in the treatment of postherpetic neuralgia (PHN), but neither is suited for the eye in patients with ophthalmic PHN. Herein, we examined the effect of LDC 4% eye drops on ophthalmic PHN pain. METHODS: Twenty-four patients with ophthalmic PHN were randomized to receive 0.4 mL eye drops of either LDC 4% or saline placebo (PBO) in the painful eye. After a 7-day period, the patients were crossed over to receive the alternative eye drops. The pain in the eye and the forehead was assessed with a visual analog scale (VAS) before and 15 minutes after treatment. Patients used a descriptive scale to grade pain outcome and were asked to note whether the pain returned and how long after therapy it recurred. RESULTS: LDC significantly decreased the VAS score of persistent pain in the eye (baseline: 5.9 +/- 2.2 cm; 15 minutes after eye drops: 0.9 +/- 1.8 cm, mean +/- SD [P < 0.01]) and in the forehead (baseline: 6.3 +/- 2.0 cm; 15 minutes after eye drops: 2.6 +/- 2.7 cm [P < 0.01]). The delta change in these VAS scores between LDC and PBO was significant (P < 0.01). Moreover, pain was described as moderate or better by 23 patients after they received LDC and 4 patients of the PBO group. The effect of LDC persisted for a median of 36 hours (range, 8-96 hours) after application. CONCLUSIONS: This study suggests that LDC provides a significant improvement of ophthalmic PHN because of its prompt analgesia, lack of systemic side effects, and convenience of use.

Effects of intravenous prostaglandin E1 on pain and body temperature in patients with post-herpetic neuralgia.

OBJECTIVE: Bathing, heating, or sympathetic blockade often alleviates pain due to post-herpetic neuralgia (PHN), suggesting that blood flow may affect PHN pain. Here, we examined the effect of prostaglandin E1 (PGE), which improves blood circulation, on pain and body temperature in patients with PHN. DESIGN: Twenty-four patients with PHN were enrolled in a randomized, double-blind, placebo-controlled, crossover study. After 30-minute rest in a temperature-controlled (20 degrees C) and intravenous cannulation, patients were randomized to receive either 60 microg of PGE dissolved in 100 mL of saline, or 100 mL of saline at an infusion rate of 0.03 microg/kg/min. Following a 7-day washout period, patients were crossed over to receive the other treatment. The visual analog scale (VAS) of ongoing pain and tactile allodynia, and skin and the tympanic temperatures were measured before and after infusion. RESULTS: The two solutions significantly decreased the VAS for ongoing pain, and the reduction was greater with PGE than placebo (P < 0.05). Although the temperatures of the forehead, hand, foot, chest, abdomen, and the most painful region were significantly increased in the two solutions, the elevation in the foot and the most painful region was greater with PGE than placebo (P < 0.01). The tympanic temperature did not significantly change following infusion of PGE. CONCLUSIONS: Intravenous infusion of PGE produces analgesia associated with elevation of skin temperature in patients with PHN.

Comparison of cutaneous anesthetic effect of 8% lidocaine spray with lidocaine patch using current perception threshold test.

OBJECTIVE: A lidocaine patch is often used for topical anesthesia prior to venipuncture, but needs to be applied for several hours before the puncture, and the site is fixed. A metered-dose lidocaine pump spray could be used to produce cutaneous topical anesthesia. In this study, we compared the anesthesia between the spray and the patch. DESIGN: Thirteen healthy male volunteers received three treatments of metered-dose 8% lidocaine spray, a lidocaine patch, and no application as control measurement, in a random order separated by at least 2 days. Each treatment was applied topically on the forearm. Sensory nerve fibers (Abeta, Adelta, and C fibers) were evaluated with a series of 5, 250, and 2,000 Hz stimuli using current perception threshold (CPT) before and 30 minutes after each application. RESULTS: Under the control condition, CPTs measured at baseline and at 30 minutes were similar for 2,000 and 250 Hz stimuli, but significantly reduced for 5 Hz stimulation at 30 minutes. Under patch application, CPTs for 2,000 and 250 Hz stimuli at 30 minutes after application were significantly higher than baseline, while CPTs for 5 Hz stimulation at baseline and 30 minutes after application were similar. Under spray application, CPTs for all stimuli at 30 minutes were significantly higher than baseline. CONCLUSIONS: Similar to the lidocaine patch, the lidocaine spray produces cutaneous weak anesthesia at 30 minutes after treatment. The spray seems to produce local anesthesia faster than the patch.

Efficacy of a metered-dose 8% lidocaine pump spray for patients with post-herpetic neuralgia.

OBJECTIVE: Topical lidocaine patch is effective in the treatment of post-herpetic neuralgia (PHN), but not suited for paroxysmal pain because of the long latency of analgesia. Here, we examined the efficacy of 8% lidocaine pump spray (Xylocaine pump spray, XPS) for PHN. DESIGN: Twenty-four patients with PHN were recruited into a randomized, double-blind, placebo-controlled, crossover study (study 1), and 100 patients with PHN were recruited into an open-labeled study (study 2). In study 1, patients were randomized to receive either XPS or saline placebo pump spray (PPS) applied to the painful skin areas. Following a 7-day period, patients were crossed over to receive the alternative treatment. In study 2, XPS was prescribed for patients who were advised to use the spray anytime, with a 2-hour gap between applications, for 2 weeks. The pain was assessed with a visual analogue scale (VAS). Details of use were noted in the diary. RESULTS: In study 1, greater decreases in VAS of persistent pain followed application of XPS (baseline: 6.1 +/- 1.7 cm, 15-minute post-spray: 2.3 +/- 2.5 cm, mean +/- SD) than with PPS (6.1 +/- 1.7 cm, 5.7 +/- 1.6 cm, [P < 0.01]). The effect persisted for a median of 4.5 hours (range, 2 to 24 hours) after application. In study 2, 13 of 100 patients discontinued the treatment because of mild local side effects or insufficient effect. In the remaining 87 patients, XPS maintained significant pain relief relative to baseline throughout the 2-week period. Satisfaction with the therapy was reported by 79% of patients. CONCLUSIONS: In both studies, XPS provided a significant improvement in PHN due to its prompt analgesia, lack of systemic side effects, and convenience of use.

8% Lidocaine pump spray relieves pain associated with peripheral blood flow disorders.

OBJECTIVES: It is often difficult to reduce pain associated with peripheral blood flow disorders (PBFD) using standard analgesics. We assessed the analgesic effects of a metered-dose 8% lidocaine in patients with PBFD. METHODS: Twenty-four patients with PBFD-related pain were enrolled in this double-blind placebo-controlled crossover study. Patients were randomized to receive either 8% lidocaine or saline on the painful site with a metered-dose spray. After a 3-day period, patients were crossed over to receive the alternative treatment. Pain was assessed with a visual analog scale (VAS) before and 15 minutes after the treatment. Patients were also asked to record the time at which pain appeared again. The blood concentration of lidocaine was measured at 15, 30, and 60 minutes after lidocaine application. RESULTS: There were no significant differences in VAS before treatment between the placebo and lidocaine treatments. However, lidocaine significantly decreased VAS at rest from 5.5+/-3.1 cm (mean+/-SD) to 0.6+/-0.9 cm and on movement from 8.4+/-2.0 cm to 1.7+/-1.7 cm, resulting in a significant difference between the 2 sprays. The median time to recurrence of pain was 3 hours. The blood concentration of lidocaine was less than 0.3 microg/mL in all patients. DISCUSSION: A metered-dose 8% lidocaine pump spray produced prompt analgesia in patients with PBFD-related pain without severe side effects.

The analgesic effect of a metered-dose 8% lidocaine pump spray in posttraumatic peripheral neuropathy: a pilot study.

BACKGROUND: A topical lidocaine patch is effective in the treatment of posttraumatic peripheral neuropathy (PTPN), but it is not suited for breakthrough pain because of difficulty with an additional application. Here, we examined the effect of 8% lidocaine pump spray (Xylocaine pump spray, XPS) on peripheral neuropathic pain caused by surgery or injury. METHODS: Thirty-one patients with PTPN were randomized to receive either XPS or saline placebo pump spray applied to painful skin areas. The optimal dose of up to 30 sprays (0.1 mL/single spray, 30 times) was individually determined as the dose which completely covered the painful site. After a 7-day period, the patients were crossed over to receive the optimal dose of the alternative spray. Pain was assessed with a visual analog scale. RESULTS: XPS, but not placebo pump spray, significantly decreased the visual analog scale for continuing pain and tactile allodynia. The effect persisted for a median of 5 h (range, 2-60 h) after application. Mild side effects were reported in three patients with XPS consisting of local irritation (n = 3) and local flare (n = 1). All adverse events disappeared without medication within a few hours. CONCLUSIONS: The present study suggests that XPS provides a significant improvement in PTPN due to its prompt analgesia, lack of systemic side effects and convenience.