The efficacy of injecting a distillate of the pitcher plant (Sarraceniaceae) adjacent to the palmar digital nerves of horses to ameliorate lameness caused by digital pain

This study aimed to determine the efficacy of instilling extract of the pitcher plant around the palmar digital nerves of horses to ameliorate digit pain causing lameness. Five mixed breed horses were recruited. Horses were determined to be lame because of pain in the distal portion of one or both thoracic limbs by a positive response to a basisesamoid nerve block using 2%^mepivacaine hydrochloride. Gait was evaluated pre- and post-nerve block at 30 min, 3, 7,14 and 21 days. At the 3-week evaluation, the basisesamoid nerve block was repeated using the extract, and the gait was evaluated at similar times. Lameness was evaluated objectively using a wireless, inertial, sensor-based, motion analysis system. The basisesamoid nerve block significantly ameliorated lameness at 30 min when gait was evaluated, but it had no significant effect on lameness after this time. The product containing extract of the pitcher plant had no significant effect on lameness when administered as a basisesamoid nerve block at any time. Extract of the pitcher plant administered adjacent to the medial and lateral palmar digital nerves (i.e., a basisesamoid nerve block) had no efficacy in ameliorating lameness in the distal portion of one or both thoracic limbs. Extract of the pitcher plant likely has no value for treating horses for chronic pain when administered as a regional nerve block.

Injectable and topical local anesthetics for acute dental pain: 2 systematic reviews

BACKGROUND

Local anesthesia is essential for pain control in dentistry. The authors assessed the comparative effect of local anesthetics on acute dental pain after tooth extraction and in patients with symptomatic irreversible pulpitis.

TYPES OF STUDIES REVIEWED

The authors searched MEDLINE, EMBASE, Cochrane Central Register of Controlled Trials, and the US Clinical Trials registry through November 21, 2020. The authors included randomized controlled trials (RCTs) comparing long- vs short-acting injectable anesthetics to reduce pain after tooth extraction (systematic review 1) and evaluated the effect of topical anesthetics in patients with symptomatic pulpitis (systematic review 2). Pairs of reviewers screened articles, abstracted data, and assessed risk of bias using a modified version of the Cochrane risk of bias 2.0 tool. The authors assessed the certainty of the evidence using the Grading of Recommendations Assessment, Development and Evaluation approach.

RESULTS

Fourteen RCTs comparing long- vs short-acting local anesthetics suggest that bupivacaine may decrease the use of rescue analgesia and may not result in additional adverse effects (low certainty evidence). Bupivacaine probably reduces the amount of analgesic consumption compared with lidocaine with epinephrine (mean difference, -1.91 doses; 95% CI, -3.35 to -0.46; moderate certainty) and mepivacaine (mean difference, -1.58 doses; 95% CI, -2.21 to -0.95; moderate certainty). Five RCTs suggest that both benzocaine 10% and 20% may increase the number of people experiencing pain reduction compared with placebo when managing acute irreversible pulpitis (low certainty).

PRACTICAL IMPLICATIONS

Bupivacaine may be superior to lidocaine with epinephrine and mepivacaine with regard to time to and amount of analgesic consumption. Benzocaine may be superior to placebo in reducing pain for 20 through 30 minutes after application.

Mepivacaine Versus Bupivacaine for Spinal Anesthesia: A Systematic Review and Meta-analysis of Random Controlled Trials

INTRODUCTION

Bupivacaine is a more widely used anesthetic than mepivacaine. However, the long-acting effects of bupivacaine often lead to slow and unpredictable return. As an intermediate-acting local anesthetic, mepivacaine can enable earlier ambulation and thus has other benefits. We performed a systematic review and meta-analysis of available randomized controlled trials (RCTs) comparing the anesthetic effects of mepivacaine and bupivacaine.

METHODS

On August 12, 2021, a search was performed in PubMed, Embase, and the Cochrane Library. Effect estimates with 95% CI were combined using a random effects model. We performed sensitivity analyses to explore sources of heterogeneity and stability of results.

RESULTS

Of the 406 papers screened, 14 population-based randomized controlled trials were included, with a total of 1007 patients. Overall, compared to bupivacaine, mepivacaine was associated with higher numbers of motor block 3 (OR, 4.05; 95% CI 1.92-8.57), shorter length of stay (SMD, - 0.77; 95% CI - 1.52 to - 0.03), faster recovery from motor block (SMD, - 1.45; 95% CI - 2.39 to - 0.51), and shorter time to return to voiding (SMD, - 1.24; 95% CI - 1.83 to - 0.64). Mepivacaine was associated with a higher incidence of transient neurologic symptoms (TNS) and transient nerve root irritation (TRI) (OR, 9.18; 95% CI 2.42-34.88). There was no statistical difference between the two anesthetics in terms of pain index on the postoperative day (SMD, 0.20; 95% CI - 0.06 to 0.46) and incidence of urinary retention (OR, 0.98; 95% CI 0.47-2.03).

CONCLUSIONS

Mepivacaine may have advantages over bupivacaine in terms of achieving motor block 3, shorter length of stay, earlier recovery from motor block, and earlier time to return to voiding, but it may have a higher incidence of TNS or TRI than bupivacaine. Therefore, mepivacaine may be used before bupivacaine in spinal anesthesia.

Effects of intra-articular administration of lidocaine, mepivacaine, and the preservative methyl parahydroxybenzoate on synovial fluid biomarkers of horses

OBJECTIVE

To compare the extent of inflammation and catabolic collagen response in the middle carpal joints (MCJs) of healthy horses following intra-articular injection of 2% lidocaine, 2% mepivacaine, lactated Ringer solution (LRS), or 0.1% methyl parahydroxybenzoate.

ANIMALS

17 adult horses.

PROCEDURES

In the first of 2 experiments, the left middle carpal joint (MCJ) of each of 12 horses was injected with 10 mL of 2% lidocaine (n = 3), 2% mepivacaine (3), or LRS (control; 6). After a 4-week washout period, the right MCJ of the horses that received lidocaine or mepivacaine was injected with 10 mL of LRS, and the right MCJ of horses that received LRS was injected with 10 mL of 2% lidocaine (n = 3) or 2% mepivacaine (3). In experiment 2, the left MCJ of each of 5 horses was injected with 10 mL of 0.1% methyl parahydroxybenzoate. After a 48-hour washout period, the right MCJ of each horse was injected with 10 mL of LRS. Synovial fluid (SF) samples were aseptically collected before and at predetermined times after each injection. Synovial fluid WBC count, neutrophil percentage, and total protein, neutrophil myeloperoxidase, neutrophil elastase, and Coll2-1 concentrations were compared among treatments.

RESULTS

Both lidocaine and mepivacaine induced SF changes indicative of inflammation and a catabolic collagen response, but the magnitude of those changes was more pronounced for lidocaine. Methyl parahydroxybenzoate did not cause any SF changes indicative of inflammation.

CONCLUSIONS AND CLINICAL RELEVANCE

Results suggested that mepivacaine was safer than lidocaine for intra-articular injection in horses.

Effect of 3% chloroprocaine hydrochloride when used for median and ulnar regional nerve blocks in lame horses

OBJECTIVE

To assess onset of analgesia for 3% chloroprocaine hydrochloride and 2% mepivacaine hydrochloride when used for median and ulnar nerve blocks in lame horses.

ANIMALS

6 naturally lame horses.

PROCEDURES

A crossover experiment was conducted. Horses were assigned to 1 of 2 treatment groups (3% chloroprocaine or 2% mepivacaine first). Median and ulnar nerve blocks were performed in the lame limb with the assigned treatment. Lameness was objectively evaluated before treatment administration and at various points for 120 minutes after treatment with a wireless inertial sensor-based motion analysis system. Following a 7-day washout period, horses then received the other treatment and lameness evaluations were repeated.

RESULTS

Median and ulnar nerve blocks performed with 3% chloroprocaine resulted in more consistent, rapid, and profound amelioration of lameness than did blocks performed with 2% mepivacaine. Lameness decreased more between 20 and 40 minutes after injection when 3% chloroprocaine was used than when 2% mepivacaine was used. Complete resolution of lameness was detected a mean of 9 minutes after injection when median and ulnar nerve blocks were performed with 3% chloroprocaine and a mean of 28 minutes after injection when performed with 2% mepivacaine.

CONCLUSIONS AND CLINICAL RELEVANCE

3% chloroprocaine had a more rapid onset and provided better analgesia for median and ulnar nerve blocks in horses with naturally occurring lameness, compared with 2% mepivacaine. These favorable properties suggest that 3% chloroprocaine would be useful for performance of median and ulnar regional nerve blocks during complicated lameness evaluations.

Retrospective analysis of mepivacaine, prilocaine and chloroprocaine for low-dose spinal anaesthesia in outpatient perianal procedures

PURPOSE

Perianal procedures are carried out in an outpatient setting regularly. The purpose of this retrospective analysis was to investigate the impact of different local anaesthetics (LA) for spinal anaesthesia (SPA) on operating room (OR) efficiency (perioperative process times, turnaround times) and postoperative recovery. This study aims on the determination of the optimal LA for low-dose SPA in the specific setting of a high-volume day-surgery centre.

METHODS

Anaesthesia records of all patients undergoing perianal outpatient surgery under saddle-block SPA at the Mannheim University Medical Centre from 2008 until 2017 were analysed. Patients were categorized as having received prilocaine, mepivacaine or chloroprocaine.

RESULTS

Two thousand seven hundred forty-six patients were included. Postoperative recovery was faster for chloroprocaine 1% compared with both other LAs. Preoperative processes but not process times in the OR were shorter for chloroprocaine. In contrary, turnaround times were significantly prolonged when chloroprocaine had been used, leading to reduction of OR efficiency.

CONCLUSION

Low-dose SPA provides reliable blocks for perianal surgery. Considerations on the choice of LA for SPA must include not only the recovery profile, but also the impact on OR efficiency. Due to shorter turnaround times and a manageable prolonged duration of stay, prilocaine is the preferable LA for low-dose SPA in perianal outpatient surgery at a high-volume day-surgery centre.

Multi-Acupuncture Point Injections and Their Anatomical Study in Relation to Neck and Shoulder Pain Syndrome (So-Called Katakori) in Japan

Katakori is a symptom name that is unique to Japan, and refers to myofascial pain syndrome-like clinical signs in the shoulder girdle. Various methods of pain relief for katakori have been reported, but in the present study, we examined the clinical effects of multi-acupuncture point injections (MAPI) in the acupuncture points with which we empirically achieved an effect, as well as the anatomical sites affected by liquid medicine. The subjects were idiopathic katakori patients (n = 9), and three cadavers for anatomical investigation. BL-10, GB-21, LI-16, SI-14, and BL-38 as the WHO notation were selected as the acupuncture point. Injections of 1 mL of 1% w/v mepivacaine were introduced at the same time into each of these points in the patients. Assessment items were the Pain Relief Score and the therapeutic effect period. Dissections were centered at the puncture sites of cadavers. India ink was similarly injected into each point, and each site that was darkly-stained with India ink was evaluated. Katakori pain in the present study was significantly reduced by MAPI. Regardless of the presence or absence of trigger points, pain was significantly reduced in these cases. Dark staining with India ink at each of the points in the anatomical analysis was as follows: BL-10: over the rectus capitis posterior minor muscle and rectus capitis posterior major muscle fascia; GB-21: over the supraspinatus muscle fascia; LI-16: over the supraspinatus muscle fascia; SI-14: over the rhomboid muscle fascia; and BL-38: over the rhomboid muscle fascia. The anatomical study suggested that the drug effect was exerted on the muscles above and below the muscle fascia, as well as the peripheral nerves because the points of action in acupuncture were darkly-stained in the spaces between the muscle and the muscle fascia.

Mepivacaine: a closer look at its properties and current utility

The use of mepivacaine in dentistry has remained strong since its introduction in the 1960s. It has retained its place as a valuable local anesthetic, either as a primary agent or as an alternative to lidocaine or articaine. Mepivacaine is commonly used in medically compromised patients--for whom elevations in blood pressure or heart rate are not advisable--in a formulation with a vasoconstrictor, or in pediatric populations in a formulation without a vasoconstrictor. Pharmacologically, these are the 2 groups most susceptible to side effects and toxicity, thus mepivacaine is commonly indicated. Most often the decision to use mepivacaine is based on its vasoconstrictor effect or lack thereof (depending on the formulation). However, the pharmacokinetics of mepivacaine are not well understood or assumed to be similar to that of other local anesthetics. It is important to understand the unique pharmacologic characteristics of mepivacaine in order to minimize the potential for inadvertent toxicity.

[Pharmakological characteristic of some amide local anesthetics, currently used in dental clinics]

Along with the brief history of amide local anesthetics development, their most important properties (from the viewpoint of use in clinical dental practice), are also reviewed. In particular, some properties of most commonly used local anesthetics, such as lidocaine, mepivacaine, prilocaine, bupivacaine and articaine are analysed. The most important data concerning pharmacological mechanisms of mentioned anesthetics' action, that cause certain features and peculiarities of their clinical application are given in condensed form. Besides, some precaution measures that must be taken into account in specific clinical cases together with the history and current status of each patient are mentioned as well.

Ultrasound-guided posterior approach to brachial plexus for the treatment of upper phantom limb syndrome

The purpose of the case is to report the clinical value of the ultrasound-guided posterior approach to the brachial plexus in the treatment of phantom limb syndrome after an upper extremity amputation. The author experienced ultrasound guidance as sole technique to localize the brachial plexus for the purpose of placing a catheter for continuous infusion of a local anesthetic in a patient where standard landmark-based nerve stimulation for placement of a continuous perineural block was not possible.

Ultrasound-guided treatment of meralgia paresthetica (lateral femoral cutaneous neuropathy): technical description and results of treatment in 20 consecutive patients

OBJECTIVES

The purposes of this study were to describe a technique for treatment of meralgia paresthetica (lateral femoral cutaneous neuropathy) using ultrasound guidance and to report the results of treatment.

METHODS

Twenty consecutive patients (7 male and 13 female; age range, 23-66 years; mean, 39 years) with meralgia paresthetica confirmed by electromyography were treated with perineural injection of 1 mL of methylprednisolone acetate (40 mg/mL) and 8 mL of mepivacaine, 2%, under direct ultrasound guidance. Main outcome measures included the technical success of the procedure, visual analog scale score for the lateral femoral cutaneous nerve (pain, burning sensation, and paresthesia), and visual analog scale global quality of life score.

RESULTS

Technical success (successful nerve block at the distribution of the lateral femoral cutaneous nerve) was achieved in all patients. Five patients felt slight sharp pain during needle insertion. The symptoms in 16 patients (80%) diminished progressively after the first week. The 4 remaining patients (20%) required a further perineural injection. The symptoms disappeared in all patients 2 months after injection (mean visual analog scale score ± SD for lateral femoral cutaneous neuropathy at baseline, 8.1 ± 2.1; at 2 months, 2.1 ± 0.5; t = 6.2; P < .001). The mean visual analog scale quality of life scored decreased from 6.9 ± 3.2 to 2.3 ± 2.5 (t = 5.3; P < .002).

CONCLUSIONS

Treatment of meralgia paresthetica with ultrasound-guided perineural injections resulted in substantial symptom relief in most patients 2 months after injection. Randomized placebo-controlled trials of this treatment should be considered in the future.

Testing whether the epidural works: too time consuming?

BACKGROUND

When using epidural anaesthesia (EDA) for pain relief after major surgery, a failure rate of 10% is common. A crucial step in improving the care of patients with EDA is to define the position of the epidural catheter. The aim of this study was to investigate how much time it takes to determine whether the block is sufficient by assessing the extent of loss of cold sensation before induction of anaesthesia.

METHODS

One hundred patients listed for abdominal surgery were included in the study. After an epidural catheter had been inserted and an intrathecal or an intravenous position had been made unlikely by the use of a test dose, the patient was given a bolus dose of local anaesthetic plus an opioid in the epidural catheter. The epidural block was tested every 2 min, starting at 5 min and ending at 15 min. When at least four segments were blocked bilaterally, the testing was stopped, the time was noted and the patient was anaesthetised.

RESULTS

An epidural block was demonstrated after 5-6 min in 37 patients, after 7-8 min in 43 additional patients and after 9-10 min in 15 patients. In one patient, it took 12 min and in three patients, it took 15 min. In two patients, no epidural block could be demonstrated.

CONCLUSION

Testing an epidural anaesthetic before the induction of anaesthesia takes only 5-10 extra minutes. Knowing whether the catheter is correctly placed means better quality of care, giving the anaesthetist better prerequisites for taking care of the patient post-operatively.

Periprostatic nerve block before ultrasound-guided prostate biopsy: a comparison of two local anesthetics

The objective of the present study was to evaluate the efficacy of the periprostatic nerve block (PNB) of the prostate-vesicular junction with low volume and high concentration of anesthetics in relieving pain during prostate biopsy. Two hundred and twenty patients were enrolled and randomized to receive PNB with 5 ml 2% lidocaine (group 1110 pts) and PNB with 5 ml 2% mepivacaine (group 2, 110 pts). The anesthetic was administered through a single puncture on each side at the prostate-vesicular junction using a 22-gauge needle. All patients filled in a ten visual analogue pain score scale (VAS) from 0 = no discomfort to 10 = severe pain, for the assessment of pain experienced during biopsy. The two groups were homogeneous concerning the anthropometrical data. The mean pain score with lidocaine was 1.4 +/- 1.02 (CI 95% = 1.53 to 3.57) and with mepivacaine was 1.3 +/- 1.06 (CI 95% = 2.66 +/- 4.84) with no statistical significant difference between groups (p = 0.43). No general or local adverse effects were observed between the anaesthetics. The use of a low volume (2.5 ml on each side) and high concentration (2%) of local anesthetics (lidocaine/mepivacaine) almost completely suppresses pain and discomfort associated with prostate biopsy. The anatomy of neurovascular bundle regions appears favourable to the administration of small amounts of anesthetic.

The pillar pain in the carpal tunnel's surgery. Neurogenic inflammation? A new therapeutic approach with local anaesthetic

AIM

After the surgical decompression of the transverse carpal ligament as treatment of the tunnel carpal syndrome, pillar pain manifestation is possible. This is a painful and temporary invaliding syndrome with unknown aetiology. Aim of the study is to demonstrate that pillar pain is based on autonomic irritation that disappears with simple infiltration of local anaesthetic (LA), or rather by neuromodulation.

METHODS

Eighty-four patients were enrolled for this study and underwent an open release technique surgery. They were then asked for regular postoperative follow-ups.

RESULTS

Thirty-two out of 84 patients (38%) developed pillar pain. Accordingly, injection of LA as pain treatment has since been studied and results compared with the conventional protocol for this painful syndrome.

CONCLUSION

Even if the number of the patients considered is not great, there is evidence of a decrement of pillar pain by means of LA injections. Excellent functional outcomes and satisfaction were achieved using LA infiltrations for pillar pain after carpal tunnel decompression. The minimally invasive technique offers a quick, easy, effective, and inexpensive method useful to minimize and cure in a few days the pillar pain.

Reduction of pulmonary edema by short-acting local anesthetics

BACKGROUND AND OBJECTIVES

Local anesthetics (LAs) possess a variety of effects that cannot be explained by the typical block of neuronal sodium channels. Antithrombotic effects of LAs are well known, but LAs also act as bactericides. Therefore, an investigation of the influence of LAs on the inflammatory response of the isolated rat lung (n = 78) to an N-formyl-l-leucin-methionyl-l-phenylalanine (FMLP) stimulus was performed.

METHODS

The experiments were performed on isolated and ventilated rat lungs perfused with cell-free and plasma-free buffer. LAs (lidocaine and mepivacaine) were injected in various concentrations before application and activation of human granulocytes by FMLP. Pulmonary arterial pressure (PAP) and lung weight gain were monitored continuously. LAs in final dosages from 10(-2) to 10(-7) mg/kg body weight (n = 6 each) were injected into the pulmonary artery before treatment with FMLP (10(-6) M) to induce pulmonary arterial hypertension. Perfusate samples were taken intermittently to determine thromboxane A(2) (TX A(2)) and endothelin-1 concentrations. Microscopic analyses were performed to assess the degree of lung injury.

RESULTS

Pretreatment with LAs significantly reduced the FMLP-induced PAP increase (treatment group v sham group: 0.5 to 5 mm Hg v 8 mm Hg; P < .05) and the release of endothelin-1 (2.4 v 5 fmol/mL). Histologic damage seen as acute granulocytic alveolitis was reduced by lidocaine and mepivacaine, even below clinically relevant concentrations.

CONCLUSION

LA pretreatment reduces inflammatory reactions after FMLP stimulus.

Comparison between neurotropin and mepivacaine for stellate ganglion injection

Neurotropin, a nonproteinaceous extract from the inflamed skin of rabbits inoculated with vaccinia virus, is reported to decrease pain effectively when used for stellate ganglion (SG) injection. We compared the effects of neurotropin SG injection with those of mepivacaine on pain relief, as well as comparing the side effects. One hundred and eighty-eight SG injections in 15 patients (5 with postherpetic neuralgia and 10 with sudden deafness) were performed either with 1% mepivacaine 6 ml or with neurotropin 3 ml combined with saline 3 ml in turn. Fifteen min before and after the injection, the pain score, according to a visual analog scale (VAS; only in patients with postherpetic neuralgia); blood pressure; and heart rate were checked, and the number of procedures with Horner's sign was determined. VAS scores decreased significantly with both injections. Horner's sign was observed on the block side in all procedures with the mepivacaine injection, but it was seen in only 48 procedures with the neurotropin injection. Blood pressure and heart rate did not change. In conclusion, the SG injection of neurotropin decreased the VAS score in postherpetic neuralgia to the same extent as mepivacaine. The incidence of Horner's sign was significantly lower with neurotropin than with mepivacaine.

A comparison of mepivacaine versus lidocaine for episcleral (sub-tenon's) block for cataract surgery in an ambulatory setting

BACKGROUND AND OBJECTIVES

For eye surgery, motor block is still often requested by the surgeon. For cataract surgery, rapid block resolution allows eyelids to move and allows eye-patch removal. Therefore, short-duration block is useful in early rehabilitation for ambulatory surgery. Lidocaine is classically assumed to have shorter duration than mepivacaine. Therefore, lidocaine alone might be considered as an alternative to mepivacaine.

METHODS

In this randomized, double-blind study, we compared mepivacaine 2% (n = 22) and lidocaine 2% (n = 25) in 47 patients who received episcleral (sub-Tenon's) block for cataract surgery. Akinesia score was measured 1, 5, 10, and 15 minutes and 1, 2, 4, and 6 hours after the end of injection. Primary outcome was block duration (time from injection to full recovery). Secondary outcomes were time to block onset and best akinesia score for each patient. Complications were recorded.

RESULTS

The 2 groups were similar for demographic and anesthetic features. We observed no significant difference between mepivacaine and lidocaine in terms of onset, quality of akinesia, and block duration. One case of ocular hypertonia and 1 case of strabismus were observed in the lidocaine group, which could be imputed to hyaluronidase unavailability during the study period or to increased lidocaine myotoxicity.

CONCLUSIONS

We found no argument to favor lidocaine over mepivacaine in episcleral (sub-Tenon's) eye block, especially in terms of motor-block duration.

Nerve blocks at the wrist for carpal tunnel release revisited: the use of sensory-nerve and motor-nerve stimulation techniques

BACKGROUND AND OBJECTIVES

Because the median nerve at the wrist has mainly sensory endings, the aim of this study was to assess the response of the median nerve to nerve stimulation at the wrist and to evaluate the quality of median nerve block. A control group of patients who received blinded injections was analyzed and compared post hoc.

METHODS

One hundred and eleven patients scheduled for ambulatory endoscopic carpal-tunnel release performed under median and ulnar nerve blocks at the wrist were prospectively studied. The blocks were performed with a nerve stimulator. Nerve-stimulation techniques were explained to the patient before the block was performed. The patient was trained to inform the anesthetist of their perception of an electrical paresthesia that was synchronized to the nerve stimulator. The anesthetist recorded the first response of the patient to nerve stimulation: sensory (S), sensory-motor (SM), or motor response (M). When the minimal stimulating current was obtained, an equal volume of 4 mL of 1.5% mepivacaine was injected on median and ulnar nerves. If necessary, a lateral subcutaneous injection of 2 mL of 1.5% mepivacaine was administered at the wrist crease in the musculocutaneous nerve area. Thirty-five patients who received blinded local anesthetics injections were included post hoc. Quality of anesthesia was compared between groups.

RESULTS

Responses included 89 S (80.2%), 18 SM (16.2%), and 4 M (3.71%). No differences occurred in time to perform the block, minimal current intensity, and efficacy. More punctures were necessary in the M group compared with the S group and the control group (P < .05). The onset time of sensory blocks increased significantly in control-group patients (P < .05), but the duration of the nerve-block procedure decreased in comparison with the M group. Respectively, 10% and 20% of patients experienced mild or severe pain in the nerve-stimulation group and control group. At 20 minutes, the block was complete for the median and ulnar nerves in 96.4% and 85% of the nerve-stimulation patients and control patients (P < .05). Two patients in the control group experienced painful mechanical paresthesia. Neither permanent nor transient nerve injuries were observed during or after the nerve block or surgery.

CONCLUSION

This study describes how infrequently an initial motor response is identified when a nerve stimulator is used on the median nerve at the wrist. A very high success rate of median and ulnar nerve block at the wrist is obtained by use of sensory or sensory-motor-nerve stimulation and less than 10 mL of anesthetic solution.

Biochronomer™ technology

Biochronomer (AP Pharma) is a fourth-generation poly(ortho ester) prepared by the condensation of diols and a diketene acetal. The polymer contains a copolymerised latent acid whose concentration controls erosion rate. The polymer has been shown to undergo a surface erosion process and a number of applications have been explored. Among these, the delivery of plasmid DNA for vaccines is currently of most interest. This application takes advantage of the acid-labile nature of the polymer, which leads to rapid polymer hydrolysis and hence rapid release of plasmid DNA once internalised in the acidic environment within the endosomes, and the non-acidic environment within the polymer that conserves plasmid DNA conformation. A low molecular semisolid polymer is now in Phase II clinical trials for the delivery of mepivacaine to control postoperative pain, and in Phase I clinical trials for the systemic delivery of granisetron to control nausea.

The effects of clonidine added to mepivacaine for paronychia surgery under axillary brachial plexus block

We hypothesized that onset of sensory block is delayed in infected versus healthy tissues within the same nerve distribution after axillary brachial plexus block (ABPB) and that clonidine added to mepivacaine would enhance anesthesia and postoperative analgesia. Forty-one outpatients undergoing thumb/index paronychia surgery under ABPB were randomly assigned to receive in a double-blind fashion 400 mg mepivacaine plus either 100 microg clonidine (clonidine group, n = 21) or 2 mL saline (placebo group, n = 20). Onset of sensory block in the infected area was delayed compared with healthy areas of the same nerve distribution (24.7 +/- 5.5 min versus 21.3 +/- 7.2; P = 0.02 for median and 21.6 +/- 7.8 min; P = 0.04 for radial) within the placebo group. In the clonidine group, when compared to placebo i) onset of sensory block in both the median and radial nerve territories was accelerated (11.1 +/- 5.6 and 10.5 +/- 5.2 versus 21.3 +/- 7.2 and 21.6 +/- 7.8 min, respectively; P < 0.001), ii) onset of sensory block in the region of infection was accelerated (9.1 +/- 1.9 versus 24.7 +/- 5.5 min; P < 0.001), iii) duration of anesthesia (275 +/- 75 versus 163 +/- 57; P = 0.04) and time to first analgesic requirement (279 +/- 87 versus 197 +/- 84 min; P = 0.002) were prolonged with decreased visual analog scale scores at this time (30 +/- 18 versus 70 +/- 24; P < 0.001), and iv) verbal numeric rating scores were decreased at 24 h (1.7 +/- 2.2 versus 4.1 +/- 3.0; P = 0.002) and 48 h (0.1 +/- 0.5 versus 1.5 +/- 2.4; P = 0.01) postoperatively. Our findings suggest that in the setting of distal infected tissue surgery under ABPB infected tissues are resistant to anesthesia compared with healthy areas within the same nerve distribution and clonidine added to mepivacaine enhances both anesthesia and postoperative analgesia.

Effects of head-up tilt after stellate ganglion block on QT interval and QT dispersion

BACKGROUND AND OBJECTIVES

The aim of this study is to examine the effects of head-up tilt (70 degrees ) 30 minutes after right or left stellate ganglion block (SGB) on RR interval, QT interval, the rate-corrected QT (QTc) interval, QT dispersion (QTD), and the rate-corrected QT dispersion (QTcD) using computerized measurement.

METHODS

Ten healthy volunteers underwent both right and left SGBs using 7 mL 1% mepivacaine with a 7-day interval between the two blocks. A 12-lead electrocardiogram was monitored to measure parameters before SGB; 30 minutes after SGB (before head-up tilt); and immediately, 5, 10, and 15 minutes after head-up tilt.

RESULTS

Right SGB induced significant increases in QT interval, QTc interval, QTD, and QTcD from 30 minutes after the block through 15 minutes after head-up tilt. There were significant increases of QT interval, QTc interval, and QTcD between before and immediately after head-up tilt in right SGB. Left SGB induced significant decreases of QT interval and QTc interval from 30 minutes after SGB through 15 minutes after head-up tilt. Left SGB also induced a significant decrease of QTD from immediately after through 10 minutes after head-up tilt.

CONCLUSIONS

Significant increases of QT interval, QTc interval, and QTcD, which are associated with an increased risk of ventricular arrhythmias and cardiac events, occur immediately after head-up tilt in right SGB. However, head-up tilt does not induce increases of QT interval, QTc interval, QTD, and QTcD in left SGB.

The bifid axillary artery

The anesthetic of a patient who presented for vascular access under axillary block is described. After physical examination and ultrasound study, the patient was found to have a bifid axillary artery. Because of neurologic anomalies associated with this vascular variation, an interscalene block was chosen for the procedure. The clinical implications of a bifid axillary artery when an axillary block is contemplated are discussed.

Intraarticular corticosteroid injection: pain relief in osteoarthritis of the hip?

OBJECTIVE

Osteoarthritis (OA) is one of the most common causes of morbidity in the elderly population, and surgery is often preceded by years of pain and disability. Intraarticular corticosteroid injections in osteoarthritic joints may play a role in the therapeutic plan and can afford quick pain relief but do not alter the underlying disease. There is a paucity of well controlled studies that provide recommendations for the use of corticosteroids in OA of the hip.

METHODS

A prospective analysis of 80 patients with OA of the hip and pain at rest and on bearing weight for more than 4 weeks was performed. Patients were randomized into 2 groups; group 1 (n = 40) received corticosteroid (80 mg triamcinolone acetonide) and group 2 (n = 40) local anesthetic (1% mepivacaine), injected into the hip joint under fluoroscopy. Pain, functional ability, range of motion of the joint, and analgesics consumed were registered 3 weeks postinjection. The treatment was blind for the patients and the investigators performing the followup.

RESULTS

Pain for all modalities decreased after corticosteroid injection, but pain at rest decreased the most. There was significant pain reduction at the 3 (and 12) week followup. Joint range of motion increased significantly for all directions. Functional ability improved significantly after injection. We found no significant pain relief or improvement of functional ability in patients treated with local anesthetics.

CONCLUSION

This study suggests that intraarticular corticosteroids might improve pain and range of motion of the affected joint in patients with hip OA.

Median versus musculocutaneous nerve response with single-injection infraclavicular coracoid block

BACKGROUND AND OBJECTIVES

Local anesthetic injection after elicitation of a distal motor response with a nerve stimulator is believed to produce a more clinically efficient infraclavicular coracoid block than after elicitation of a proximal motor response. The aim of this study was to investigate whether elicitation of a median or of a musculocutaneous-type nerve response influenced the quality of anesthesia.

METHODS

Randomized, prospective, single-blind study. One hundred thirty patients received a coracoid block with 40 mL plain mepivacaine 1.5% after stimulation of median nerve fibers (group 1) or musculocutaneous nerve fibers (group 2). Patients were assessed for sensory and motor block at 5 and 20 minutes.

RESULTS

Significantly higher rates of complete anesthesia at 20 minutes were found in the cutaneous distributions of the radial and ulnar nerves in group 1. Significantly higher rates of complete paralysis were found for elbow extension, wrist flexion, and finger and thumb movements in group 1 at 20 minutes. Differences in the extent of anesthesia and paralysis were more remarkable at 5 minutes than at 20 minutes.

CONCLUSIONS

Elicitation of a median nerve response improved the efficacy of infraclavicular coracoid block when compared with a musculocutaneous nerve response. Complete paralysis and complete anesthesia of the upper limb were low in both groups.

Continuous local cooling for pain relief following total hip arthroplasty

This study is the first to evaluate whether continuous cryotherapy can relieve pain soon after total hip arthroplasty (THA). Patients who had undergone THA for osteoarthritis were divided into 2 prospective, randomized groups: the cryotherapy group was fitted with a computer-controlled cooling device for 4 days, and the control group was not. The pain scores measured on a visual analog scale between days 1 and 4 following surgery were significantly lower for the cryotherapy group than for the control group. Furthermore, postoperative analgesic use by the cryotherapy group was significantly lower than by the control group. The results of this study support the potential benefit of a cold compressive device for pain reduction during the postoperative recovery of patients undergoing THA.

Amniotic fluid embolism with second trimester pregnancy termination: a case report

PURPOSE

Describe the diagnosis, clinical features, pathophysiology, treatment and anesthetic management of amniotic fluid embolism (AFE) in a patient undergoing second trimester pregnancy termination.

CLINICAL FEATURES

A 30-yr-old gravida 2, para 1, woman was admitted for a dilatation and evacuation procedure for underlying intra-uterine fetal demise in her second trimester of pregnancy. Hypotension, shock, respiratory arrest, pulseless electrical activity, hemorrhage, disseminated intravascular coagulopathy, requiring cardiopulmonary resuscitation and blood transfusion complicated her intraoperative care. AFE was considered the most likely cause of this intraoperative event.

CONCLUSIONS

It is now recognized that the pathophysiological features of AFE are similar to a type-1 hypersensitivity reaction ranging from mild systemic reaction to anaphylaxis and shock. AFE has a high maternal and fetal morbidity and mortality rate, requiring prompt recognition and treatment. In patients with cardiovascular instability, the treatment of AFE is similar to anaphylaxis requiring aggressive fluid hydration, cardiopulmonary resuscitation, administration of blood products and the use of vasopressors.

Toothache of Nonodontogenic Origin: A Case Report

This article describes the diagnosis and treatment of a patient exhibiting nonodontogenic tooth pain. A 25-yr-old female patient presented to postgraduate endodontics, SUNY at Stony Brook, for evaluation and treatment of pain associated with the upper and lower left quadrants. After thorough intraoral and extraoral examinations, it was determined that the pain was referred to the dentition from a trigger point in the masseter muscle. An extraoral injection of 3% Carbocaine was administered into the trigger point, and the pain abated within 5 min. The patient has experienced no recurrence of this pain for 12 months. Consideration of nonodontogenic dental pain should be included in a differential diagnosis.

[Comparative efficiency of local anesthetics from the group of complex amides during therapeutic stomatological interventions]

The efficiency of infiltration, conduction, and intraligamental anesthesia with different drugs for dental interventions was evaluated in 331 patients without concomitant somatic diseases. The efficiency of local anesthesia depends primarily on the drug; other essential factors are the route of this drug administration and type of intervention in the oral cavity. The most effective of the studied anesthetics was 4% artisane with epinephrine 1:100,000; 3% prolocaine with epinephrine 1:100,000 ranked second. These anesthetics maximally realized their effects at intraligamental injection during the treatment of caries and periodontitis.

Oral dexketoprofen for pain treatment during diagnostic hysteroscopy in postmenopausal women

OBJECTIVE

To assess the efficacy of dexketoprofen (DEX) in reducing pain at different stages of the hysteroscopic procedure in comparison with local anaesthesia in menopausal women.

METHODS

Menopausal patients affected by uterine bleeding submitted to diagnostic hysteroscopy, were randomised to receive either 25 mg DEX tablet (n = 148) or intracervical injection of 5 ml mepivacaine 2% (n = 150). Pain suffered during the procedure itself and 30, 60, 120 min after, was scored on the 11 point Visual Analogic Scale, recorded and analysed.

RESULTS

No statistical difference were noted during the procedure itself in both groups of treatment. Patients treated with DEX has significantly less postoperative pain.

CONCLUSIONS

DEX is not superior to mepivacaine in reducing the discomfort of the procedure but does significantly reduce postoperative pain.

Interscalene brachial plexus block with continuous intraarticular infusion of ropivacaine

Providing intraarticular analgesia with a continuous infusion of local anesthetic via a disposable infusion pump has gained popularity. Despite the prevalence of this technique, data comparing this method of analgesia to conventional regional anesthesia are not available. We present a prospective study that compared a single-dose interscalene block with a single-dose interscalene block plus continuous intraarticular infusion of local anesthetic. Forty patients scheduled for shoulder arthroscopy were entered in this prospective, double-blinded study. All patients received an interscalene brachial plexus block as their primary anesthetic. Patients were randomly assigned to 1 of 2 groups: 1. interscalene block with 1.5% mepivacaine (40 mL) followed by a postoperative intraarticular infusion of 0.5% ropivacaine at 2 mL/h, or 2. interscalene block with 0.5% ropivacaine (40 mL) followed by a postoperative intraarticular infusion of 0.9% saline (placebo) at 2 mL/h. Postoperative infusions were maintained for 48 h. Visual analog scale pain scores and postoperative oxycodone consumption were measured for 48 h. Visual analog scale scores at rest and with ambulation in the Mepivacaine/Intraarticular Ropivacaine group were reduced when compared with the Ropivacaine/Saline group (rest: P = 0.003, ambulation: P = 0.006). Oxycodone consumption was also decreased (28 +/- 21 mg vs 44 +/- 28 mg, P = 0.046), respectively. We conclude that a brachial plexus block with 1.5% mepivacaine and a continuous intraarticular infusion of 0.5% ropivacaine at 2 mL/h provides improved analgesia for minor surgery at 24 and 48 h versus a single-injection interscalene block with 0.5% ropivacaine.

A comparison of the effects of local analgesic solution in the navicular bursa of horses with lameness caused by solar toe or solar heel pain

We hypothesised that analgesia of the navicular bursa is not selective for the navicular apparatus; and that solar pain in some horses can be temporarily abolished or attenuated by analgesia of the navicular bursa. To test this hypothesis, we caused lameness in horses by inducing pain in the dorsal margin or the angles of the sole and then evaluated the ability of a local analgesic solution administered into the navicular bursa to attenuate lameness. The response of horses with solar pain in the dorsal or palmar aspect of the foot to 3.5 ml local analgesic solution administered into the navicular bursa was examined. Lameness was induced in 6 horses by creating solar pain in the dorsal aspect of one forefoot and, at another time, the palmar aspect of the other forefoot, with set-screws inserted into a custom-made shoe. Horses were videotaped trotting before and after application of set-screws and after administering 3.5 ml local analgesic solution into the navicular bursa. Lameness scores were assigned by examining videotaped gaits. Scores were significantly lower (P<0.05) for all horses with set-screws applied to the dorsal margin of the sole after administration of local analgesic solution into the navicular bursa. In conclusion, analgesia of the navicular bursa was less effective in desensitising the angles of the sole than in desensitising the dorsal margin of the sole. Pain arising from the sole should not be excluded as a cause of lameness when lameness is attenuated by analgesia of the navicular bursa.

The effect of bilateral palmar digital nerve analgesia on the compressive force experienced by the navicular bone in horses with navicular disease

Horses with navicular disease have an increased load on the navicular bone in early stance. This has been suggested to be a response to pain in the heel region. Seven horses with clinical, radiographic and scintigraphic signs of navicular disease underwent forceplate and kinematic analysis before and after desensitisation of the heel region with a bilateral palmar digital nerve block. The compressive force exerted on the navicular bone during stance, and stride kinematics, were determined in each state. After regional analgesia of the palmar digital nerves (PDNB) the compressive force on the navicular bone was lower throughout stance. The mean +/- s.d. peak force at the beginning of stance was 7.05+/-1.10 N/kg before, and 6.46+/-1.15 N/kg after PDNB (P = 0.01) and at the end of stance the mean peak values were 5.00+/-2.05 N/kg before, and 4.39+/-1.65 N/kg after PDNB (P = 0.05). We explained this finding as indicating that the horse responds to heel pain (including pain in the navicular region) by contracting the deep digital flexor muscle to unload the heels. This increases the compressive load on the navicular bone, which may cause remodelling and, in some horses, damage to the overlying flexor cartilage, which is then painful and identified as navicular disease. This mechanism identifies navicular disease as a possible end point for a variety of heel related conditions.

Headshaking in horses: possible aetiopathogenesis suggested by the results of diagnostic tests and several treatment regimes used in 20 cases

Twenty mature horses with typical headshaking of 2 week-7 year duration were studied. Clinical examinations included radiography of the head and nasopharyngeal endoscopy. All were assessed at rest and at exercise, both before and after fitting an occlusive nasal mask, application of tinted contact lenses and the perineural anaesthesia of the infraorbital and posterior ethmoidal branches of the trigeminal nerve. Infraorbital anaesthesia had no effect in 6/7 cases but 11/17 (65%) cases showed a 90-100% improvement following posterior ethmoidal nerve anaesthesia. Tinted contact lenses had no apparent long-term benefit, although 2 cases showed a transient improvement. We found no other evidence to suggest a photic aetiology in the current series of cases. Treatment regimens based on the results of the diagnostic investigative methods included sclerosis of the posterior ethmoidal branch of the trigeminal nerve. This was effective in some cases but the benefits were temporary. Cyproheptadine alone was ineffective but the addition of carbamazepine resulted in 80-100% improvement in 80% of cases. Carbemazepine alone was effective in 88% of cases but results were unpredictable at predefined dose rates. The positive response to carbamazepine, combined with the clinical features is consistent with involvement of the trigeminal nerve, particularly the more proximal branches such as the posterior ethmoidal nerve. Headshaking has some clinical features in common with trigeminal neuralgia in humans. As a result of the findings detailed in this paper, we conclude that a trigeminal neuritis or neuralgia may be the basis of the underlying aetiopathology of equine headshaking. Initial observations of the positive response of headshakers to carbamazepine therapy is encouraging. However, future studies will include a more detailed investigation of dosages, duration of effectiveness (in some cases it appears short-lived) and other effects. In practice there is a realistic possibility of controlling but not curing headshaking with carbamazepine therapy at the present time. Other future investigations will include details of the functional anatomy of the trigeminal nerve and the role of the P2 myelin protein in headshaking and other neurological disease.

The 'three in one' block as locoregional analgesia in an emergency department

The 'three in one' block is a well-known locoregional technique for per- and post-operative anaesthesia. This 'three in one' block was investigated in an emergency department with three combinations of local anaesthetics as a locoregional way of pain relief for patients with fractures of the upper femur. A double-blind prospective study was conducted with 61 consecutive patients. A good regression of the linear visual analogue scale (LVAS), good haemodynamic stability and great patient satisfaction were found for all groups of patients at different times after installation of the block. Side effects were few and are avoidable by reducing the amount of local anaesthetic given to elderly patients with a low bodyweight. The technique failed in only four patients due to technical reasons. It was concluded that the 'three in one' block is a fast, safe, reliable and easy technique for pain relief in an emergency department. Good analgesia was achieved for patients with fractures of the upper femur with no need to change the position of the patient.

Bone atrophy in complex regional pain syndrome patients measured by microdensitometry

PURPOSE

To determine the usefulness of quantitative measurement of bone atrophy in the diagnosis and the long-term follow-up of patients with complex regional pain syndrome (CRPS). The bone-sparing effect of a 5-hydroxytriptamine (5-HT2) antagonist was also studied.

METHODS

Bone mass was measured by computerized micro-densitometry at the middle position of the second metacarpal. The effect of repeated stellate ganglion blocks (SGBs) three times per week with mepivacaine (n = 11), administration of a 5-HT2 antagonist (sarpogrelate hydrochloride, 300 mg a day po) (n = 12), and combined therapy (n = 10) were compared by micro-densitometry and conventional visual analogue scale (VAS) for analgesia after three months of treatment.

RESULTS

In CRPS patients, metacarpal index (cortical bone thickness), maximum bone density (cortical bone density), minimum bone density (trabecular bone density), and average bone density were reduced on the affected side (14.1%, 12.1%, 25.0% and 19.3% respectively). The rate of reduction in bone mass correlated with the duration of the disease (P < 0.05). Therapy with the 5-HT2 receptor antagonist (with or without repeated SGBs) decreased pain intensity (from 6.10 to 3.81 with SGB, from 6.30 to 2.91 without SGB, respectively; P < 0.01) and bone atrophy evaluated by micro-densitometry (P < 0.05). In contrast, repeated SGBs alone reduced pain intensity (from 6.30 to 2.91; P < 0.01) but did not ameliorate bone atrophy.

CONCLUSION

Bone micro-densitometry is useful in the assessment and follow-up of CRPS and for evaluation of treatment. The 5-HT2 antagonist, sarpogrelate hydrochloride, is a promising treatment for CRPS patients.

Symptoms of spinal stenosis do not improve after epidural steroid injection

OBJECTIVE

This study was carried out to evaluate the therapeutic effect of epidural steroid injection on pseudoclaudication in patients with lumbar degenerative spinal canal stenosis.

DESIGN

Fifty-three patients who complained of pseudoclaudication of less than 20 m in walking distance were randomly divided into three groups. Group 1 (n = 16) underwent epidural injection with 8 ml of saline. Group 2 (n = 18) underwent epidural block with 8 ml of 1% mepivacaine. Group 3 (n = 19) underwent epidural block with a combination of 8 ml of 1% mepivacaine and 40 mg of methylprednisolone. The criteria of evaluation were as follows: excellent effect, > 100 m in walking distance; good effect, 20-100 m in walking distance; poor effect, <20 m in walking distance.

RESULTS

In group 1, the numbers of patients who showed a good effect were two (12.5%) after 1 week, one (6.5%) after 1 month, and one (6.5%) after 3 months. In group 2, the numbers of patients who showed a good or excellent result were 10 (55.5%) after 1 week, three (16.7%) after 1 month, and one (5.6%) after 3 months. In group 3, the numbers of patients who showed a good or excellent result were 12 (63.2%) after 1 week, three (15.8%) after 1 month, and one (5.3%) after 3 months. There was no significant difference in the effectiveness of treatment between group 2 and group 3 throughout the time course.

CONCLUSION

The results suggest that epidural steroid injection has no beneficial effect on the pseudoclaudication associated with spinal canal stenosis as compared with epidural block with a local anesthetic alone.

Comparison of the effect of EMLA and semicircular subcutaneous anaesthesia in the prevention of tourniquet pain during plexus block anaesthesia of the arm

In 54 patients who were to undergo surgery of the upper extremity in plexus block anaesthesia the effect of 5 g EMLA (group E) on tourniquet pain was examined and compared with the effect of a semicircular subcutaneous anaesthesia using 10 ml 0.25% bupivacaine (group B) or 10 ml 1% mepivacaine (group M). Among the patients with satisfactory brachial plexus analgesia allowing for surgery (n = 51), the incidence of tourniquet pain was not significantly different between groups E, M and B. Notably, there was no significant difference in the time of tourniquet application. We conclude that topical application of EMLA is as effective as a semicircular subcutaneous anaesthesia with mepivacaine or bupivacaine in the prevention of tourniquet pain during brachial plexus anaesthesia.

[The utility of digital infiltration of mepivacaine and ketorolac in postoperative analgesia of the unilateral hallux valgus]

OBJECTIVES

To determine whether locally injected ketorolac provides analgesia additional to that of mepivacaine, and also to prevent, diminish or delay the peripheral hypersensitivity response of postoperative pain.

PATIENTS AND METHODS

Prospective, randomized, double-blind study of 72 patients scheduled for surgery to correct unilateral hallux valgus. Group 1 (n = 24) received median infiltration at the first metatarsus of 5 ml of 2% mepivacaine and 1 ml (30 mg) of ketorolac. Group 2 (n = 21) received local infiltration of 5 ml of 2% mepivacaine and 1 ml of saline solution. Group 3, the control group (n = 27) received the same solution as did group 2, plus 30 mg of ketorolac intravenously. The postoperative analgesia prescribed was 10 mg of ketorolac orally every 8 hours. Pain was measured on a visual analog scale (VAS) 0, 1, 4, 8 and 24 hours after surgery. Time elapsed until the appearance of pain, number of ketorolac pills consumed and overall patient satisfaction were recorded.

RESULTS

There were no differences in anthropometric characteristics. Time until pain appeared was significantly longer in group 1 than in groups 2 and 3 (14.66 +/- 7.19, 5.90 +/- 2.27 and 8.70 +/- 5.02 hours, respectively). The VAS scores were significantly lower in group 1 after the fourth postoperative hour. Analgesic consumption was significantly lower in group 1.

CONCLUSIONS

Infiltration of 30 mg of ketorolac along with mepivacaine delays the appearance of postoperative pain and diminishes it in the first 24 hours after surgery to correct hallux valgus, in comparison with infiltration of mepivacaine alone plus intravenous ketorolac.

Evaluation of periapical injection of Ketorolac for management of endodontic pain

Effective pain management of the endodontic emergency patient is often a problem. Ketorolac tromethamine is the first nonsteroidal anti-inflammatory drug available for intramuscular injection in the United States. Although its analgesic efficacy is comparable with opiates after intramuscular injection, to date no study has evaluated its efficacy after intraoral periapical injection. Fifty-two endodontic emergency patients were injected (injection routes = intraoral infiltration/intramuscular deltoid) on a double-blind basis with either: (i) placebo/placebo, (ii) 30 mg ketorolac/placebo, (iii) placebo/30 mg ketorolac, or (iv) 2% mepivicaine with 1:20 K levonordefrin/placebo. Infiltration injection of ketorolac at on oral site produced significant analgesic effects, particularly in treating pain of mandibular origin. These results suggest that intraoral injection of ketorolac may prove to be a useful adjunct in the management of endodontic pain patients. Further studies are required to replicate these findings and to develop optimal treatment combinations.

Anaphylactic shock following povidone

OBJECTIVE

To report a patient with an anaphylactic reaction related to povidone administration.

CASE SUMMARY

A 37-year-old man with a history of allergic rhinitis presented with urticaria, dyspnea, wheezing, rhinorrhea, and dysphonia 20 minutes after the intraarticular administration of mepivacaine hydrochloride and paramethasone acetate in his right knee. Two months after this episode, he was admitted for controlled provocation tests. Tests on mepivacaine were negative. The preparation of paramethasone contained the excipients benzalkonium chloride, polysorbate 80, and povidone. In vitro tests and provocation were negative with polysorbate 80 and benzalkonium chloride, but positive with povidone.

DISCUSSION

Povidone, a mixture of synthetic polymers, is commonly used as an excipient in pharmaceutical products, an additive in food products, and a dispersant and stabilizer in hairsprays. Although it is well tolerated when used topically or parenterally, local and systemic effects have been reported. Furthermore, multiorgan involvement resulting from accumulation of the drug in the reticuloendothelial system has been described. The immunologic properties of povidone have not been explored in humans, but have been in animals. In fact, the capacity of povidone to release histamine and its immunogenicity are proportional to its molecular weight. An immunoglobulin (Ig) E-mediated hypersensitivity reaction in asthma has been reported. In our case, povidone was responsible for the syndrome. However, we cannot determine the exact mechanism. An unspecific histamine release and/or an IgE-mediated hypersensitivity could be involved.

CONCLUSIONS

Povidone was responsible for a severe anaphylactic reaction in our patient. The possibility of an iatrogenic adverse effect caused by the excipient but not by the active ingredient should be considered in patients exhibiting similar symptoms. We believe that the excipients used in the preparation of all medicines should be disclosed.

A rabbit tooth-pulp assay to quantify efficacy and duration of antinociception by local anesthetics infiltrated into maxillary tissues

The rabbit tooth-pulp assay is well established as a method for measuring the efficacy and potency of parenteral analgesic drugs. We describe a method for administration of local anesthetic drugs into the maxillary arch and subsequent measurements of antinociceptive action. It was possible to use two different methods of ED50 estimation and to provide measures of the potency, efficacy, and duration of local anesthetic drugs. These measurements corresponded with in vitro estimates of potency and duration and with intrinsic observations of the clinical actions.

The use of topical anesthesia in diagnostic hysteroscopy and endometrial biopsy

STUDY OBJECTIVE

To determine whether the pain and discomfort of routine hysteroscopy with endometrial biopsy to diagnose infertility and endometrial pathology can be minimized by topical application of mepivacaine.

DESIGN

Prospective, randomized, double-blind study.

SETTING

The Department of Obstetrics and Gynecology at a teaching hospital in Rome, Italy.

PATIENTS

Eighteen women undergoing diagnostic hysteroscopy.

INTERVENTIONS

Hysteroscopy and endometrial biopsy were performed after transcervical injection of 5 ml 2% mepivacaine or 5 ml saline solution into the uterine cavity.

MEASUREMENTS AND MAIN RESULTS

Difficulty introducing the hysteroscope was rated by the operator on a scale of 1 to 3. An observer scored visible signs of each woman's distress using a three-point scale. The patients reported their pain 15, 30, 60, 120 minutes after the procedure on a visual analog scale. Mepivacaine was more effective than placebo according to all measurements.

CONCLUSIONS

Topical mepivacaine reduced the pain experienced during and after hysteroscopy and endometrial biopsy.

[The effect of continuous epidural infusion of a combination of 1% mepivacaine and buprenorphine for post-operative pain relief]

Using a portable 2 ml.hr-1 type infusor (Baxter Infusor), the effect of continuous epidural infusion for post-operative pain relief for 72 hours was studied in 32 patients after upper abdominal surgery. The patients were randomly allocated into four groups: Group 1 (n = 8) received continuous epidural infusion of 1% mepivacaine and buprenorphine 0.2 mg (48 ml.hr-1); group 2 (n = 8) 1% mepivacaine and buprenorphine 0.4 mg (48 ml.hr-1); Group 3 (n = 8) saline and buprenorphine 0.2 mg (48 ml.hr-1); Group 4 (n = 8) saline and buprenorphine 0.4 mg (48 ml.hr-1). The effect was evaluated at intervals of 12-hour until 72 hours postoperatively. Patients received supplemental buprenorphine intramuscularly as needed. In each period during the 12 to 72-hour after operation, the percentage of the patients who needed no supplemental buprenorphine was 62.5-100%, which is higher than during the 0 to 12-hour (25.0%). The percentage of the patients who showed no pain on coughing and changing in position in Group 1 and 2 was higher than in Group 3 and 4 in each period (P less than 0.05 12-24 and 36-72 hr). Continuous epidural infusion using Baxter Infusor with the combination of 1% mepivacaine and buprenorphine is effective for alleviating postoperative pain during the 12 to 72 hours after the operation, and for prevention of pulmonary complications.