Toxicity of local anaesthetics

Does Addition of a Longer Acting Local Anesthetic Improve Postoperative Pain After Carpal Tunnel Release? A Randomized Controlled Trial

PURPOSE

Carpal tunnel release (CTR) is a simple and effective treatment for carpal tunnel syndrome in patients who have failed nonsurgical management. This surgery is often performed in the ambulatory clinic under local anesthesia, with lidocaine, a short-acting agent. Few studies have investigated the use of longer acting agents, such as bupivacaine, for outpatient CTR. Therefore, the aim of our study was to compare the postoperative pain experience after CTR with the use of either our standard lidocaine solution (control) or a mixture consisting of lidocaine and bupivacaine in equal amounts (intervention).

METHODS

Patients undergoing CTR were randomized into control or intervention groups. Postoperative pain severity and numbness were recorded at several timepoints within the first 72 hours. The timing and quantity of postoperative analgesic use (acetaminophen and/or ibuprofen) was also documented. Both patients and assessor were blinded to allocation.

RESULTS

Our study cohort included 139 patients: 67 in the control group and 72 in the intervention group. Postoperative pain scores were significantly lower in the intervention group at 6 hours (2.3 vs 3.2) and 8 hours (2.9 vs 3.9). Additionally, patients in the intervention group reported longer time to first analgesic use than those in the control group (5.2 hours vs 3.7 hours). A greater proportion of patients in the intervention group reported postoperative numbness at nearly all time points, compared to the control group.

CONCLUSIONS

Our study shows that a mixture of bupivacaine and lidocaine improves early postoperative pain but causes prolonged finger numbness when compared to lidocaine alone. As both medications are effective and feasible for outpatient CTR, surgeon and patient preference should guide local anesthetic choice.

TYPE OF STUDY/LEVEL OF EVIDENCE

Therapeutic Ib.

Effectiveness of Regional Nerve Blocks Versus Local Anesthetic Infiltration for Elective Hand and Wrist Surgery

BACKGROUND

Pain relief by different methods in elective hand and wrist surgery is pivotal for patients undergoing elective wrist and hand surgery.

AIM

To evaluate the effectiveness and duration of peripheral nerve block versus local surgical site anesthetic infiltration among patients undergoing elective wrist and hand surgery.

SUBJECTS AND METHODS

This study was carried out in the Orthopaedic Department of Duhok Emergency Teaching Hospital, Duhok, Kurdistan region, Iraq. All patients who attended the Orthopaedic Department (total number=496) for elective hand and wrist surgery between November 2021 and November 2022 were included in the study, but only 300 patients completed the study protocol after the exclusion of 196 patients. Three methods of nerve block were used for postoperative pain relief. The degree and duration of pain relief were assessed.

RESULTS

Patients who underwent ultrasound-guided nerve block had more duration of pain relief when compared to those patients who underwent local surgical site anesthetic infiltration and anatomical landmark nerve block (p<0.01), while patients who underwent local surgical site anesthetic infiltration had better pain relief when compared to those patients who underwent ultrasound-guided nerve block and anatomical landmark nerve block (p<0.01 for the group experiencing mild pain and p=0.12 for the group experiencing moderate pain and p<0.01 for the group experiencing severe pain).

CONCLUSION

Ultrasound-guided nerve block is better for a longer duration of pain relief postoperatively than local surgical site anesthetic infiltration, while local surgical site anesthetic infiltration more effectively controls the severity of pain following elective hand and wrist surgery.

Evaluation of the Erector spinae plane block for postoperative analgesia in laparoscopic ventral hernia repair: a randomized placebo controlled trial

BACKGROUND

The Erector spinae plane block (ESPB) reduces postoperative pain after several types of abdominal laparoscopic surgeries. There is sparse data on the effect of ESPB in laparoscopic ventral hernia repair. The purpose of this study was to test the postoperative analgesic efficacy of an ESPB for this procedure.

METHODS

In this prospective, double-blind, randomized controlled study, adult patients undergoing laparoscopic ventral hernia repair were randomly assigned to either bilateral preoperative ESPB with catheters at the level of Th7 (2 × 30 ml of either 2.5 mg/ml ropivacaine or saline), with postoperative catheter top ups every 6 h for 24 h. The primary outcome was rescue opioid consumption during the first hour postoperatively. Secondary outcomes were total opioid consumption at 4 h and 24 h, pain scores, nausea, sedation, as well as Quality of Recovery 15 (QoR-15) and the EuroQol-5 Dimensions (EQ-5D-5L) during the first week.

RESULTS

In total, 64 patients were included in the primary outcome measure. There was no significant difference in rescue opioid consumption (oral morphine equivalents (OME)) at one hour postoperatively, with the ESPB group 26.9 ± 17.1 mg versus 32.4 ± 24.3 mg (mean ± SD) in the placebo group (p= 0.27). There were no significant differences concerning the secondary outcomes during the seven-day observation period. Seven patients received a rescue block postoperatively, providing analgesia in five patients.

CONCLUSION

We found no difference in measured outcomes between ESPB and placebo in laparoscopic ventral hernia repair. Future studies may evaluate whether a block performed using higher concentration and/or at a different thoracic level provides more analgesic efficacy.

TRIAL REGISTRATION

NCT04438369 ; 18/06/2020. .

Sustained release local anesthetics for pain management: relevance and formulation approaches

This review attempted to ascertain the rationale for the formulation of sustained-release local anesthetics and summarize the various formulation approaches designed to date to achieve sustained and localized local analgesic effects. The incidence of pain, which is the concern of patients as well as health care professionals, is increasing due to accidents, surgical procedures, and other diseases. Local anesthetics can be used for the management of moderate to severe acute and chronic pain. They also allow regional analgesia, in situations where the cause and source of the pain are limited to a particular site or region, without the need for loss of consciousness or systemic administration of other analgesics thereby decreasing the risk of potential toxicities. Though they have an interesting antipain efficacy, the short duration of action of local anesthetics makes the need for their multiple injections or opioid adjuvants mandatory. To overcome this problem, different formulations are being designed that help achieve prolonged analgesia with a single dose of administration. Combination with adjuvants, liposomal formulations, lipid-based nanoparticles, thermo-responsive nanogels, microspheres, microcapsules, complexation with multivalent counterions and HP-β-CD, lipid-based nanoparticles, and bio-adhesive films, and polymeric matrices are among the approaches. Further safety studies are required to ensure the safe and effective utilization of sustained-release local anesthetics. Moreover, the release kinetics of the various formulations should be adequately established.

Neurological Complications of Local Anesthesia in Dentistry: A Review

Local anesthesia is a technique that temporarily desensitizes a specific body area, typically for a surgical procedure, dental work, or pain management. It is described as a sensation loss in a specific area of the body due to depression of excitation in the nerve endings or due to the inhibition of the conduction process within the peripheral nerves. It allows for safer and more comfortable medical procedures, reducing the need for general anesthesia and facilitating faster recovery. Local anesthesia is generally safe, but like any medical intervention, it carries potential risks and side effects. The complications related to local anesthetics can be assessed in terms of neurological, vascular, local, systemic, and neurological. In this review article, we discussed the neurological complications of local anesthesia related to the ophthalmic nerve, maxillary nerve, mandibular nerve, branches of the trigeminal nerve, and facial nerve. These include diplopia, ptosis, paralysis of the eye, blindness, paresthesia, trismus, soft tissue lesions, edema, hematoma, facial blanching, infection, allergy, overdose, neuralgia, facial palsy, etc.

Efficacy of lidocaine vs combination of lidocaine and bupivacaine in management of maxillofacial trauma: a clinical comparative study

BACKGROUND

The COVID-19 pandemic has created an unprecedented situation which the treatment of maxillofacial trauma, especially mandibular fractures that were previously managed using general anaesthesia had to be performed under local anaesthesia. In these cases, there was a requirement for an anaesthetic agent that would have a rapid onset but also provide a prolonged effect. The aim of the study was to evaluate the onset, duration, depth, required volume of anaesthesia of lidocaine with epinephrine versus combination of lidocaine and bupivacaine with epinephrine anaesthetic agents in surgical management of isolated mandibular fracture patients.

METHODS

A total of 30 patients with isolated mandibular fractures reported to our hospital included the study group. Patients were randomly distributed to two groups, Group A and Group B. Group A received local anaesthesia using 2% Lidocaine with 1:80,000 adrenaline and Group B received 0.5% Bupivacaine with 1:2,00,000 adrenaline combined with 2% Lidocaine with 1:80,000 adrenaline at a ratio of 1:1. The outcome variables were recorded and the data was tabulated and analysed using un-paired students t test.

RESULTS

The combination of anaesthetic agents had longer duration of action (mean: 182.47 min, P-value: 0.001) and required lesser volume of anaesthetic solutions (mean: 5.38 mL, P-value: 0.001) as compared to usage of lidocaine alone. Although combination group showed quicker onset (mean: 4 min 8 s), the result was insignificant (p-value: 0.345).

CONCLUSION

The study found that the combination of lidocaine and bupivacaine could serve as a potential anaesthetic cocktail in effective surgical management of isolated mandibular fractures.

CLINICAL RELEVANCE

Maxillofacial injuries can be managed efficiently under local anaesthesia using combination of lidocaine and bupivacaine.

The utility of a multi-orifice epidural catheter when using the "Spray-as-You-Go" technique for topical Airway Anesthesia during Flexible Bronchoscopy, a randomised trial

BACKGROUND

Lidocaine administered through the working channel of a flexible bronchoscope can provide effective local anesthesia but cannot achieve good distribution in the airway. This study was undertaken to determine whether lidocaine delivered via a multi-orifice epidural catheter (three orifices/openings) is superior to conventional method and if a better distribution and decreased the cough reflex can be achieved.

METHODS

The patients (N = 100; 50 in each group) were randomized to receive either topical airway anesthesia by the "spray-as-you-go" technique via conventional application (group C) through the working channel of the bronchoscope or via a triple-orifice epidural catheter (group E). The primary outcome measurement was the cough severity, which was documented using a 4-point scale. Bronchoscopists and nurses assessed the coughing. The visual analogue scale (VAS) score for cough, total consumption of propofol and lidocaine, requirement frequency of propofol and topical anesthesia, PACU retention time, and adverse events were also compared.

RESULTS

There was a significant difference in the median cough severity scores between the two groups (group C: 3 vs. group E: 2, P = 0.004). The median visual analogue scale (VAS) scores for the cough, were significantly higher in group C than those in group E (bronchoscopist: 3 vs. 2 P = 0.002; nurse: 3 vs. 2, P < 0.001). The incidence of cough was significantly higher in group C in the trachea, left and right bronchi. The highest respiratory rate was higher in group C than in group E (P < 0.01). Eight patients in group C and two patients in group E had an oxygen saturation below 90% during flexible bronchoscopy(FB) (P = 0.046). More patients in group C required extra topical anesthesia than in group E (P < 0.001). The total lidocaine consumption was also higher in group C than that in group E (P < 0.001).

CONCLUSIONS

Endotracheal topical anesthesia via the multi-orifice epidural catheter (three holes/openings) during flexible bronchoscopy using the "spray-as-you-go" technique was appeared to be superior to the conventional method.

Procedural sedation and analgesia versus nerve blocks for reduction of fractures and dislocations in the emergency department: A systematic review and meta-analysis

Background

Procedural sedation and analgesia (PSA) and peripheral nerve blocks (NBs) are techniques to manage pain and facilitate reduction of dislocated joints or fractures. However, it is unclear if either approach provides any distinct advantage in the emergency department (ED). The aim of this systematic review is to compare these 2 techniques on pain scores, adverse events, patient satisfaction, and length of stay (LOS) in the ED.

Methods

We performed an electronic search of MEDLINE, EMBASE, and the Cochrane Library, and references were hand-searched. Randomized controlled trials (RCTs) comparing PSA with NBs for orthopedic reductions in the ED were included. Outcomes of interest included pain scores, adverse events, patient satisfaction, and LOS in the ED. A total of 2 reviewers independently screened abstracts and extracted data into a standardized form. The Cochrane risk-of-bias tool was used to evaluate study quality. The Grading of Recommendation Assessment Development and Evaluation approach was used to assess the certainty and strength of the evidence. Data on pain scores were pooled using a random-effects model and are reported as standardized mean differences (SMDs) with 95% confidence intervals (CIs).

Results

A total of 6 RCTs (n = 256) were included in a qualitative review, and 4 RCTs (n = 101) were included in the meta-analysis. There was no significant difference in pain scores between the PSA and NB groups (P = 0.47; SMD, 0.45; 95% CI, -0.78 to 1.69; I² = 0.94). There were less adverse events in the NB group (0%-3.3%) compared with the PSA group (0%-20%; n = 256). LOS times were consistently shorter in the NB group (n = 215). Patient satisfaction was comparable in both groups (n = 196).

Conclusion

Based on the available evidence, NBs performed by emergency physicians are as effective as PSA in managing pain during orthopedic reductions in the ED. NBs are associated with fewer adverse events and shorter LOS in the ED. The quality of evidence is low.

Prophylactic effect of intravenous lidocaine against cognitive deficit after cardiac surgery: A PRISMA-compliant meta-analysis and trial sequential analysis

BACKGROUND

This study aimed at providing an updated evidence of the association between intraoperative lidocaine and risk of postcardiac surgery cognitive deficit.

METHODS

Randomized clinical trials (RCTs) investigating effects of intravenous lidocaine against cognitive deficit in adults undergoing cardiac surgeries were retrieved from the EMBASE, MEDLINE, Google scholar, and Cochrane controlled trials register databases from inception till May 2021. Risk of cognitive deficit was the primary endpoint, while secondary endpoints were length of stay (LOS) in intensive care unit/hospital. Impact of individual studies and cumulative evidence reliability were evaluated with sensitivity analyses and trial sequential analysis, respectively.

RESULTS

Six RCTs involving 963 patients published from 1999 to 2019 were included. In early postoperative period (i.e., 2 weeks), the use of intravenous lidocaine (overall incidence = 14.8%) was associated with a lower risk of cognitive deficit compared to that with placebo (overall incidence = 33.1%) (relative risk = 0.49, 95% confidence interval: 0.32-0.75). However, sensitivity analysis and trial sequential analysis signified insufficient evidence to arrive at a firm conclusion. In the late postoperative period (i.e., 6-10 weeks), perioperative intravenous lidocaine (overall incidence = 37.9%) did not reduce the risk of cognitive deficit (relative risk = 0.99, 95% confidence interval: 0.84) compared to the placebo (overall incidence = 38.6%). Intravenous lidocaine was associated with a shortened LOS in intensive care unit/hospital with weak evidence.

CONCLUSION

Our results indicated a prophylactic effect of intravenous lidocaine against cognitive deficit only at the early postoperative period despite insufficient evidence. Further large-scale studies are warranted to assess its use for the prevention of cognitive deficit and enhancement of recovery (e.g., LOS).

Case Report: Synchronous Removal and Implantation of Peritoneal Dialysis Catheter Using Bilateral Transversus Abdominis Plane Block

Background

Peritoneal dialysis (PD) surgery include PD catheter insertion and removal. Both procedures require the use of anesthesia. The end-stage renal disease (ESRD) patients usually have severe comorbidities. The general anesthesia, because of its negative systemic effect, should be omitted in this vulnerable group of the patients. Transversus abdominis plane (TAP) block as a newer method of regional anesthesia is a technique without systemic effect and recently started to be used in ESRD patients for PD catheter placement and/or removal. Here we report a patient in whom we for the first time simultaneously removed and implanted a PD catheter by using a bilateral transversus abdominis plane block.

Case Presentation

The patient was an 80-year-old man who was admitted for removal of malfunctioned PD catheter. Since the patient opted for staying on PD simultaneous implantation of catheter was planned. Because of his age and significant comorbidities, general anesthesia was avoided and bilateral TAP block become our option. In the same anesthesia, using bilateral TAP block, the old PD catheter was removed and a new one was implanted. Until now the patient is on regular PD without any complications.

Conclusion

The TAP block could be used as a primary anesthetic technique in ESRD patients for PD surgery even for synchronous removal and implantation of PD catheter.

The Potential Effect of Lidocaine, Ropivacaine, Levobupivacaine and Morphine on Breast Cancer Pre-Clinical Models: A Systematic Review

Breast cancer (BC) is one of the most common types of cancer and the second leading cause of death in women. Local anaesthetics (LAs) and opioids have been shown to influence cancer progression and metastasis formation in several pre-clinical studies. However, their effects do not seem to promote consensus. A systematic review was conducted using the databases Medline (via PubMed), Scopus, and Web of Science (2010 to December 2021). Search terms included "lidocaine", "ropivacaine", "levobupivacaine", "morphine", "methadone", "breast cancer", "breast carcinoma" and "breast neoplasms" in diverse combinations. The search yielded a total of 784 abstracts for initial review, 23 of which met the inclusion criteria. Here we summarise recent studies on the effect of analgesics and LAs on BC cell lines and animal models and in combination with other treatment regimens. The results suggest that local anaesthetics have anti-tumorigenic properties, hence their clinical application holds therapeutic potential. Regarding morphine, the findings are conflicting, but this opioid appears to be a tumour-promoting agent. Methadone-related results are scarce. Additional research is clearly required to further study the mechanisms underlying the controversial effects of each analgesic or LA to establish the implications upon the outcome and prognosis of BC patients' treatment.

Comparison of the effects of articaine and bupivacaine in impacted mandibular third molar tooth surgery: a randomized, controlled trial

Background

The aim of this randomized, triple-blind trial was to determine the anesthetic, analgesic, and hemodynamic effects of articaine and bupivacaine in the extraction of impacted mandibular third molar teeth.

Methods

Twenty-six patients who underwent removal of bilaterally symmetric mandibular third molars were randomly assigned to articaine and bupivacaine groups in a split-mouth design. The onset of anesthetic action, intraoperative comfort, total amount of solution used, duration of postoperative anesthesia and analgesia, rescue analgesic use, postoperative pain, intraoperative bleeding, and hemodynamic parameters were evaluated.

Results

In the articaine group, the onset of anesthetic activity was faster, intraoperative comfort was greater, and effective anesthesia required less local anesthetic solution. The bupivacaine group showed a significantly longer duration of postoperative anesthesia and analgesia, in addition to lower visual analog scale values at 6 and 48 hours postoperatively. There were no significant differences between the two solutions regarding rescue analgesic medication use, intraoperative bleeding, or hemodynamics.

Conclusion

Articaine showed greater clinical efficacy than bupivacaine in intraoperative anesthesia, achieving faster onset of anesthetic action and greater patient comfort while also requiring less reinforcement during surgery. However, bupivacaine was superior in terms of postoperative anesthesia, reducing postoperative pain due to its residual anesthetic and analgesic effects. Both anesthetic solutions led to similar hemodynamics at low doses in mandibular third molar surgery.

Efficacy of 5% Dextrose Water Injection for Peripheral Entrapment Neuropathy: A Narrative Review

Current non-surgical treatment for peripheral entrapment neuropathy is considered insignificant and unsustainable; thus, it is essential to find an alternative novel treatment. The technique of perineural injection therapy using 5% dextrose water has been progressively used to treat many peripheral entrapment neuropathies and has been proven to have outstanding effects in a few high-quality studies. Currently, the twentieth edition of Harrison’s Principles of Internal Medicine textbook recommends this novel injection therapy as an alternative local treatment for carpal tunnel syndrome (CTS). Hence, this novel approach has become the mainstream method for treating CTS, and other studies have revealed its clinical benefit for other peripheral entrapment neuropathies. In this narrative review, we aimed to provide an insight into this treatment method and summarize the current studies on cases of peripheral entrapment neuropathy treated by this method.

Effect of dexmedetomidine on characteristics of ultrasound-guided supraclavicular brachial plexus block with levobupivacaine-A prospective double-blind randomized controlled trial

Background and Aims:

Levobupivacaine, a less cardiotoxic s-isomer of bupivacaine, is proved to be similar to bupivacaine, hence, proposed as a safer alternative for nerve blocks. We aimed to evaluate the effect of perineural and intravenous dexmedetomidine on characteristics of ultrasound-guided supraclavicular brachial plexus block (BPB) performed with levobupivacaine. The aim of this study is to evaluate the effect of perineural and intravenous dexmedetomidine on characteristics of ultrasound-guided supraclavicular BPB performed with levobupivacaine.

Material and Methods:

A prospective, randomized double-blind control trial done on 120 patients undergoing elective upper limb surgical procedures under supraclavicular BPB. The enrolled patients were allocated to one of the three groups: Group L - 0.5% levobupivacaine +0.9% normal saline (NS) IV infusion; Group LDI - 0.5% levobupivacaine + dexmedetomidine (1 mcg/kg) in NS IV infusion; and Group LDP - 0.5% levobupivacaine +1 mcg/kg of dexmedetomidine perineural + NS IV infusion. The onset and duration of sensory and motor blockade were recorded in minutes. One-way ANOVA was used to observe any differences between the groups, and post hoc comparisons were conducted after Bonferroni correction for multiple comparisons.

Results:

The onset of sensory and motor blockade in Group LDP was significantly shorter than Group L and Group LDI. The duration of sensory blockade in Group LDP was significantly longer than Group LDI and Group L. The duration of motor blockade in Group LDP was prolonged compared to Group LDI and Group L.

Conclusions:

When dexmedetomidine is added as adjunct to levobupivacaine in supraclavicular BPB, onset of sensory and motor blockade is faster in perineural group, whereas duration of sensory and motor blockade and duration of analgesia are more prolonged when used perineurally than intravenously.

Influence of Pharyngeal Anaesthesia on Post-Bronchoscopic Coughing: A Prospective, Single Blinded, Multicentre Trial

Background: Local anaesthesia of the pharynx (LAP) was introduced in the era of rigid bronchoscopy (which was initially a conscious procedure under local anaesthetic), and continued into the era of flexible bronchoscopy (FB) in order to facilitate introduction of the FB. LAP reduces cough and gagging reflex, but its post-procedural effect is unclear. This prospective multicentre trial evaluated the effect of LAP on coughing intensity/time and patient comfort after FB, and the feasibility of FB under propofol sedation alone, without LAP. Material and methods: FB was performed in 74 consecutive patients under sedation with propofol, either alone (35 patients, 47.3%) or with additional LAP (39 patients, 52.7%). A primary endpoint of post-procedural coughing duration in the first 10 min after awakening was evaluated. A secondary endpoint was the cough frequency, quality and development of coughing in the same period during the 10 min post-procedure. Finally, the ease of undertaking the FB and the patient’s tolerance and safety were evaluated from the point of view of the investigator, the assistant technician and the patient. Results: We observed a trend to a shorter cumulative coughing time of 48.6 s in the group without LAP compared to 82.8 s in the group receiving LAP within the first 10 min after the procedure, although this difference was not significant (p = 0.24). There was no significant difference in the cough frequency, quality, peri-procedural complication rate, nor patient tolerance or safety. FB, including any additional procedure, could be performed equally well with or without LAP in both groups. Conclusions: Our study suggests that undertaking FB under deep sedation without LAP does to affect post-procedural cough duration and frequency. However, further prospective randomised controlled trials are needed to further support this finding.

Update on Local Anesthetic Toxicity, Prevention and Treatment During Regional Anesthesia in Infants and Children

Local anesthetic agents play a key role in the treatment and prevention of pain in children. Although generally safe and effective, as with any pharmacologic agent, adverse effects may occur with the administration of these medications. Systemic absorption or inadvertent systemic injection during bolus dosing or continuous infusion can result in local anesthetic systemic toxicity with life-threatening neurological and cardiac complications. The following article reviews the pharmacology of local anesthetic agents, outlines previous reports of systemic toxicity during regional anesthesia, and discusses prevention and treatment algorithms.

Comparison of the onset time between 0.375% ropivacaine and 0.25% levobupivacaine for ultrasound-guided infraclavicular brachial plexus block: a randomized-controlled trial

At centers with pressure on rapid operating room turnover, onset time is one of the important considerations for choosing a local anesthetic drug. To hasten the onset of the block, higher concentrations of local anesthetics are sometimes used. However, the use of diluted local anesthetics may be safer. Therefore, we aimed to compare the onset times of equipotential levobupivacaine and ropivacaine at low concentrations for infraclavicular brachial plexus block. Adult patients undergoing upper extremity surgery under ultrasound-guided infraclavicular brachial plexus block at our center were randomly allocated to the levobupivacaine and ropivacaine groups. Infraclavicular brachial plexus block was induced with 0.25% levobupivacaine or 0.375% ropivacaine depending on the assigned group. The degrees of sensory and motor blockade were assessed for 40 min after the administration of local anesthetics. A total of 46 patients were included in the analysis. Infraclavicular brachial plexus block with 0.25% levobupivacaine and 0.375% ropivacaine provided sufficient surgical anesthesia. The sensory onset time of 0.375% ropivacaine was shorter than that of 0.25% levobupivacaine (group R, 15 [15.0–22.5] min; group L, 30 [17.5–35.0] min, p = 0.001). There were no significant differences in other block characteristics and clinical outcomes between the two groups. Thus, when a quicker block onset is required, 0.375% ropivacaine is a better choice than 0.25% levobupivacaine.

Trial registration ClinicalTrials.gov (NCT03679897).

Image-guided Sports Medicine and Musculoskeletal Tumor Interventions: A Patient-Centered Model

The spectrum of effective musculoskeletal (MSK) interventions is broadening and rapidly evolving. Increasing demands incite a perpetual need to optimize services and interventions by maximizing the diagnostic and therapeutic yield, reducing exposure to ionizing radiation, increasing cost efficiency, as well as identifying and promoting effective procedures to excel in patient satisfaction ratings and outcomes. MSK interventions for the treatment of oncological conditions, and conditions related to sports injury can be performed with different imaging modalities; however, there is usually one optimal image guidance modality for each procedure and individual patient. We describe our patient-centered workflow as a model of care that incorporates state-of-the-art imaging techniques, up-to-date evidence, and value-based practices with the intent of optimizing procedural success and outcomes at a patient-specific level. This model contrasts interventionalist- and imaging modality-centered practices, where procedures are performed based on local preference and selective availability of imaging modality or interventionalists. We discuss rationales, benefits, and limitations of fluoroscopy, ultrasound, computed tomography, and magnetic resonance imaging procedure guidance for a broad range of image-guided MSK interventions to diagnose and treat sports and tumor-related conditions.

Intravenous lipid emulsion modifies synaptic transmission in hippocampal CA1 pyramidal neurons after bupivacaine-induced central nervous system toxicity

Local anesthetics can cause severe toxicity when absorbed systemically. Rapid intravenous administration of lipid emulsion (LE) is the standard of care for severe local anesthetic systemic toxicity which can cause cardiovascular and central nervous system (CNS) injury. The biological mechanism by which LE alleviates CNS toxicity remains unknown and understudied. Previous research has suggested that local anesthetics cause an imbalance of excitatory and inhibitory transmission in the brain. Therefore, this study aimed to observe the effect of LE on glutamate- and GABA-induced currents in CA1 pyramidal neurons after bupivacaine-induced CNS toxicity. We further characterized post-synaptic modifications in these cells to try to elucidate the mechanism by which LE mediates bupivacaine-induced CNS toxicity. Sprague-Dawley rats received intravenous bupivacaine (1 mg kg^-1  min^-1 ) in either normal saline or LE (or LE without bupivacaine) for 5 min. An acute brain slice preparation and a combination of whole-cell patch clamp techniques and whole-cell recordings were used to characterize action potential properties, miniature excitatory, and inhibitory post-synaptic currents, and post-synaptic modifications of excitatory and inhibitory transmission in CA1 hippocampal pyramidal neurons. The expression level of GABAA receptors were assessed with western blotting, whereas H&E and TUNEL staining were used to assess cytoarchitecture and apoptosis levels respectively. Bupivacaine treatment significantly increased the number of observed action potentials, whereas significantly decreasing rheobase, the first interspike interval (ISI), and hyperpolarization-activated cation currents (Ih) in CA1 pyramidal neurons. LE treatment significantly reduced the frequency of miniature inhibitory post-synaptic currents and enhanced GABA-induced paired pulse ratio with 50 ms interval stimulation in bupivacaine-treated rats. Regulation of GABAA levels is a promising mechanism by which LE may ameliorate CNS toxicity after systemic absorption of bupivacaine.

Video-tracking and high-speed bright field microscopy allow the determination of swimming and cardiac effects of D. magna exposed to local anaesthetics

Local anaesthetics are among the most used drugs in clinical practice, but once they are released to the environment, the effects on the aquatic fauna remain uncertain. This study evaluates, for the first time, the impact of tetracaine, lidocaine and bupivacaine on the survival rate and physiological effects of cladocera Daphnia magna. Video-tracking and image processing allowed us to obtain changes in behaviour parameters like swimming average velocity and mean square displacement. We found that tetracaine shows the most severe effect. A high-speed microscopy system was also used to determine the response of D. magna heart to these drugs. Our results show that tetracaine presents dose-dependent area reduction during all cardiac cycle, while bupivacaine and lidocaine did not present significative effects on heart size. The tested drugs, at environmental high concentrations, altered behaviour, heart function and survival of D. magna.

Local Anesthetics: Pharmacology and Special Preparations

Local anesthetics are the only class of drugs that can block transduction and transmission of nociception. Physical properties, mechanism of action, and pharmacokinetics of this class of drugs are reviewed in this article. The clinical use, such intravenous administration of lidocaine, and local and systemic toxic effects are covered. A review of current studies published in the human and veterinary literature on lidocaine patches (Lidoderm) and liposomal bupivacaine (Experal and Nocita) are discussed.

Review on the use of zebrafish embryos to study the effects of anesthetics during early development

Over the years, the potential toxicity of anesthetics has raised serious concerns about its safe use during pregnancy. As evidence emerged from research in animal models, showing that some anesthetic drugs are potential teratogenic, the determination of the risk of exposures to anesthetic drugs at early life stages became mandatory. However, due to inaccessibility and ethical constrains related to experimental conditions, the use of early life stages in mammalian models is limited. In this regard, some animal and nonanimal models have been suggested to surpass mammalian use in experimentation. Among them, the zebrafish embryo test has been recognized as a promising alternative in toxicology research, as well as an inexpensive and practical test. Substantial information collected from developmental research following compounds exposure, has contributed to the application of zebrafish assays in research, although only a few studies have focused on the use of early life stages of zebrafish to evaluate the developmental effects of anesthetics. Based on the recent advances of science and technology, there is a clear potential for zebrafish early life stages to provide new insights into anesthetics teratogenicity. This review provides an overview of recent anesthesia research using zebrafish embryos, demonstrating its usefulness to the anesthesia field, discussing the recent findings on various aspects related to the effects of anesthetics during early life development and the strengths and limitations of this model system.

Delivery of bupivacaine from UHMWPE and its implications for managing pain after joint arthroplasty

Total joint replacement is a widely used and successful surgical approach. Approximately 7 million US adults are currently living with a hip or knee replacement. However, the surgical procedures for total joint replacement are associated with significant postoperative pain, and current strategies do not adequately address this pain, which leads to patient dissatisfaction, reduced mobility, and increased risk of opioid addiction. We hypothesized that the ultra-high-molecular-weight polyethylene (UHMWPE) bearing surfaces used in total joint prosthetics could provide sustained release of the local anesthetic bupivacaine to provide relief from joint pain for an extended period of time after surgery. In this paper, we describe the production of bupivacaine-loaded UHMWPE (BPE) and measure the in vitro bupivacaine release kinetics of BPE. We found that bupivacaine could be released from BPE at clinically relevant rates for up to several days and that BPE possesses antibacterial effects. Therefore, bupivacaine-loaded UHMWPE is a promising material for joint replacement prostheses, and future studies will evaluate its safety and efficacy in in vivo models. STATEMENT OF SIGNIFICANCE: Total joint replacement is associated with significant pain and risk of infection. In our paper, we introduce bupivacaine-loaded ultra-high-molecular-weight polyethylene (BPE), which releases bupivacaine, a pain-treating drug, at doses comparable to currently used doses. Additionally, BPE inhibits the growth of infection-causing bacteria. Therefore, BPE may be able to reduce both postsurgical pain and risk of infection, potentially treating two of the most prominent complications associated with total joint replacement. To our knowledge, this is the first development of a material that can address both complications, and devices incorporating BPE would represent a significant advancement in joint arthroplasty prosthetics. More generally, the incorporation of therapeutic agents into ultra-high-molecular-weight polyethylene could impact many orthopedic procedures owing to its ubiquity.

The Effect of Intraoperative Vertebral Anesthesia on Osteoporotic Fractures Treated With Percutaneous Kyphoplasty: A Prospective Cohort Study

STUDY DESIGN

A prospective randomized cohort study.

OBJECTIVE

The objective of this study was to investigate the effect of intraoperative vertebral anesthesia on osteoporotic vertebral compression fractures (OVCFs) when treated with percutaneous kyphoplasty (PKP).

SUMMARY OF BACKGROUND DATA

Only a few studies have evaluated the intraoperative pain reducing strategies during PKP.

MATERIALS AND METHODS

A total of 64 patients with OVCFs were enrolled in the study. All of the patients were randomized into 2 groups: the traditional local anesthesia group (from the skin to the periosteum, group A) and the experimental group (from the skin to a vertebral body, group B). Visual Analogue Scale (VAS) score was used to evaluate the degree of pain at six time points, that is, VAS before surgery, VAS during balloon dilation, VAS during bone cement injection, VAS soon after surgery, and VAS 12 hours and 24 hours after surgery. In addition, we noted the patients' willingness to undergo reoperation if necessary, and the variations in surgical complications between the 2 groups.

RESULTS

There was no significant difference in VAS score before surgery between the 2 groups (t=1.694, P=0.095). The VAS scores during balloon dilatation, bone cement injection and soon after surgery were significantly different between the 2 groups (t=4.405, P=0.000; t=2.481, P=0.016; t=2.992, P=0.004, respectively). The willingness to undergo reoperation was significantly different between 2 groups (χ=6.020, P=0.049), whereas the complications showed no significant difference (χ=0.000, P=0.754).

CONCLUSIONS

Traditional local anesthesia combined with vertebral anesthesia was effective in alleviating perioperative pain during PKP. No serious complication was noted during the operation.

LEVEL OF EVIDENCE

Level I.

Rectal enema of bupivacaine in cancer patients with tenesmus pain - case series

Introduction: Rectal tenesmus pain in cancer patients most frequently appears in patients with colon cancer, and as a consequence of radiotherapy of the hypogastrium region. Treatment with opioids and adjuvant analgesics is often ineffective. Patients and methods: Here, we report on two female patients diagnosed with colon and ovary cancer, respectively, who had very severe tenesmus pain (numerical rating scale 8-10) despite using high doses of opioids, including methadone with corticosteroids, anticonvulsants, antidepressants and ketamine. Results: In both patients, bupivacaine was administered via a rectal enema. In the first patient, bupivacaine was administered at a dose of 100 mg 0.1% (100 mL), and subsequently 100 mg 0.2% (50 mL), leading to effective analgesia for 8 and 12 hrs, respectively. In the second patient, 100 mg 0.1% (100 mL) was initially administered, followed by 100 mg 0.2% (50 mL), leading to effective analgesia for 12 and 17 hrs, respectively, with only dull abdominal pain reported that was relieved by 100 mg IV ketoprofen and complete disappearance of tenesmus pain. Rectal bupivacaine administration did not cause neurologic adverse effects, heart function disturbances or decreased blood pressure. A volume of 50 mL was enough to cover a painful area in the colon. Initial bupivacaine concentrations in the blood serum did not exceed 50 ng/mL and eventually dropped to 20 ng/mL and below. Conclusions: Administration of 100 mg bupivacaine as a rectal enema is safe and provides effective analgesia, and this procedure may be conducted in hospital departments and out-patient clinics. Furthermore, this procedure in the case of pain recurrence, can be repeated, and by providing effective pain relief often allows time for the patient to be transferred to a specialized pain center.

Convulsion and Atrial Fibrillation after Transforaminal Cervical Epidural Lidocaine Injection

Lidocaine has been widely used as a local anesthetic as well as an antiarrhythmic. Its use in epidural anesthesia is increasing, which has introduced new risk and potential for harm not associated with older indications. We present a case of convulsion and atrial fibrillation seen after transforaminal cervical epidural injection with two milliliters of 2% lidocaine (40 milligrams) that resolved with no long-term sequelae. Patient had a negative serum lidocaine level. With cervical epidural injections being a common treatment for radicular pain, it is important for medical providers to be aware of the various complications associated with this procedure.

Practical guide for the management of systemic toxicity caused by local anesthetics

Systemic toxicity from local anesthetics can occur in any of the wide range of situations in which these agents are used. This practical guide is created to generate a shared awareness of the prevention, diagnosis, and treatment of local anesthetic systemic toxicity among all medical professionals who perform nerve blocks. Systemic toxicity of local anesthetic is induced by an increase of its protein-unbound plasma concentration. Initial symptoms are characterized by central nervous system signs such as excitation, convulsions, followed by loss of consciousness and respiratory arrest. These symptoms are often accompanied with cardiovascular signs such as hypertension, tachycardia and premature ventricular contractions. Further increase of plasma concentration of local anesthetic induces bradycardia, conduction disturbances, circulatory collapse and asystole. The incidence of local anesthetic systemic toxicity is 1-11 cases per 10,000. Infants, patients with decreased liver function and low cardiac output are vulnerable to systemic toxicity. When performing regional anesthesia, the guideline-directed monitoring, securing a venous line, preparation of medication to treat convulsions and lipid emulsions are required. For prevention of local anesthetic systemic toxicity, small-dose, divided administration, using agents with low toxicity such as ropivacaine and levobupivacaine, performing an aspiration test are recommended. If systemic toxicity is suspected, halt administration of local anesthetic, request assistance, secure venous line, airway, administration of 100% oxygen and if necessary tracheal intubation and artificial respiration should be immediately performed. Benzodiazepines are recommended to treat convulsions. Administration of 20% lipid emulsion according to the protocol is recommended to treat severe hypotension and arrhythmia.

Opiate-Free Pain Therapy Using Carbamazepine-Loaded Microparticles Provides Up to 2 Weeks of Pain Relief in a Neuropathic Pain Model

INTRODUCTION

Opioids remain a mainstay in the treatment of acute and chronic pain, despite numerous and potentially dangerous side effects. There is a great unmet medical need for alternative treatments for patients suffering from pain that do not result in addiction or adverse side effects. Anticonvulsants have been shown to be effective in managing pain, though high systemic levels and subsequent side effects limit their widespread usage. Our goal was to determine if the incorporation of an anticonvulsant, carbamazepine, into a biodegradable microparticle for local sustained perineural release would be an efficacious analgesic following a peripheral injury.

METHODS

Following induction of the chronic constriction injury model in Sprague-Dawley rats, mechanical allodynia testing was performed using von Frey filaments and thermal allodynia was evaluated using the Hargreaves method. Histology and blood work were performed to evaluate toxicity as well as to monitor drug and metabolite presence over time.

RESULTS

A 2-fold increase in hindpaw withdrawal thresholds in animals receiving carbamazepine-loaded microparticles relative to controls was observed for up to 14 days after treatment. Drug and metabolite had a peak blood concentration of 54.7 ng/mL and dropped off exponentially to < 5 ng/mL over a few days.

CONCLUSION

This formulation reduced systemic exposure to carbamazepine over 1,000-fold relative to traditional analgesic dosing regimens. This 2-component drug delivery system has been specifically engineered to release a controlled amount of carbamazepine over a 14-day period, providing significant pain relief with no toxicological or observable adverse events via behavioral or histochemical analysis.

Bupivacaine Indirectly Potentiates Glutamate-induced Intracellular Calcium Signaling in Rat Hippocampal Neurons by Impairing Mitochondrial Function in Cocultured Astrocytes

Background

Bupivacaine induces central neurotoxicity at lower blood concentrations than cardiovascular toxicity. However, central sensitivity to bupivacaine is poorly understood. The toxicity mechanism might be related to glutamate-induced excitotoxicity in hippocampal cells.

Methods

The intracellular free Ca2+ concentration ([Ca2+]i), mitochondrial membrane potential, and reactive oxygen species generation were measured by fluorescence and two-photon laser scanning microscopy in fetal rat hippocampal neurons and astrocytes.

Results

In astrocyte/neuron cocultures, 300 μM bupivacaine inhibited glutamate-induced increases in [Ca2+]i in astrocytes by 40% (P &lt; 0.0001; n = 20) but significantly potentiated glutamate-induced increases in [Ca2+]i in neurons by 102% (P = 0.0007; n = 10). Ropivacaine produced concentration-dependent effects similar to bupivacaine (0.3 to 300 μM). Tetrodotoxin did not mimic bupivacaine’s effects. In pure cell cultures, bupivacaine did not affect glutamate-induced increases in [Ca2+]i in neurons but did inhibit increased [Ca2+]i in astrocytes. Moreover, bupivacaine produced a 61% decrease in the mitochondrial membrane potential (n = 20) and a 130% increase in reactive oxygen species generation (n = 15) in astrocytes. Cyclosporin A treatment suppressed bupivacaine’s effects on [Ca2+]i, mitochondrial membrane potential, and reactive oxygen species generation. When astrocyte/neuron cocultures were incubated with 500 μM dihydrokainic acid (a specific glutamate transporter–1 inhibitor), bupivacaine did not potentiate glutamate-induced increases in [Ca2+]i in neurons but still inhibited glutamate-induced increases in [Ca2+]i in astrocytes.

Conclusions

In primary rat hippocampal astrocyte and neuron cocultures, clinically relevant concentrations of bupivacaine selectively impair astrocytic mitochondrial function, thereby suppressing glutamate uptake, which indirectly potentiates glutamate-induced increases in [Ca2+]i in neurons.

Antidepressant Imipramine Protects Bupivacaine-Induced Neurotoxicity in Dorsal Root Ganglion Neurons Through Coactivation of TrkA and TrkB

In our work, we used an in vitro culture model to investigate whether antidepressant imipramine (Ip) may protect bupivacaine (Bv)-induced neurotoxicity in mouse dorsal root ganglion (DRG). Adult mouse DRG was treated with 5 mM Bv in vitro to induce neurotoxicity. DRG was then pre-treated with Ip, prior to Bv, to examine its effects on protecting Bv-induced DRG apoptosis and neurite degeneration. Ip-induced dynamic changes in Trk receptors, including TrkA/B/C and phosphor (p-)TrkA/B/C, were examined by qPCR and Western blot. TrkA and TrkB were inhibited by siRNAs to further investigate their functional role in Ip- and Bv-treated DRG. Ip protected Bv-induced apoptosis and neurite loss in DRG. Ip did not alter TrkA/B/C expressions, whereas significantly augmented protein productions of p-TrkA and p-TrkB, but not p-TrkC. SiRNA-mediated TrkA or TrkB downregulation inhibited Trk receptors, and reduced p-TrkA and p-TrkB in DRG. TrkA or TrkB downregulation alone had no effect on Ip-induced protection in Bv-injured DRG. However, co-inhibition of TrkA and TrkB significantly ameliorated the protective effect of Ip on Bv-induced apoptosis and neurite loss in DRG. Imipramine protected bupivacaine-induced neurotoxicity in DRG, likely via the co-activation of TrkA and TrkB signaling pathways. J. Cell. Biochem. 118: 3960-3967, 2017. © 2017 Wiley Periodicals, Inc.

Subcostal Transverse Abdominis Plane Block for Acute Pain Management: A Review

The subcostal transverse abdominis plane (SCTAP) block is the deposition of local anesthetic in the transverse abdominis plane inferior and parallel to the costal margin. There is a growing consensus that the SCTAP block provides better analgesia for upper abdominal incisions than the traditional transverse abdominis plane block. In addition, when used as part of a four-quadrant transverse abdominis plane block, the SCTAP block may provide adequate analgesia for major abdominal surgery. The purpose of this review is to discuss the SCTAP block, including its indications, technique, local anesthetic solutions, and outcomes.

Cocaine Allergy in Drug-Dependent Patients and Allergic People

BACKGROUND

Adverse reactions to local anesthetics (LAs), especially esters, are not uncommon, but true allergy is rarely diagnosed. To our knowledge, currently there is no reliable method of determining IgE-mediated hypersensitivity to LAs and cocaine.

OBJECTIVE

To assess the clinical value of allergy tests (prick, IgE, challenges, and arrays) in people suffering hypersensitivity reactions (asthma and anaphylaxis) during local anesthesia with cocaine derivatives and drug abusers with allergic symptoms after cocaine inhalation.

METHODS

We selected cocaine-dependent patients and allergic patients who suffered severe reactions during local anesthesia from a database of 23,873 patients. The diagnostic yield (sensitivity, specificity, and predictive value) of allergy tests using cocaine and coca leaf extracts in determining cocaine allergy was assessed, taking a positive challenge as the criterion standard.

RESULTS

After prick tests, specific IgE, and challenge with cocaine extract, 41 of 211 patients (19.4%) were diagnosed as sensitized to cocaine. Prick tests and IgE to coca leaves (coca tea) had a good sensitivity (95.1% and 92.7%, respectively) and specificity (92.3 and 98.8%, respectively) for the diagnosis of cocaine allergy and LA-derived allergy.

CONCLUSIONS

Cocaine may be an important allergen. Drug abusers and patients sensitized to local anesthesia and tobacco are at risk. Both prick tests and specific IgE against coca leaf extract detected sensitization to cocaine. The highest levels were related to severe clinical profiles.

Comparison between Epidural Ropivacaine versus Ropivacaine with Clonidine in Patients Undergoing Abdominal Hysterectomy: A Randomized Study

CONTEXT

Regional anesthesia has emerged as one of the preferred and convenient modes for intra- and post-operative management owing to its advantage of not interfering with the metabolic functions, better tolerability, and decrease in reflex activity. In recent years, ropivacaine has increasingly replaced bupivacaine as a preferred local anesthetic because of its similar analgesic properties, lesser motor blockade, and decreased propensity of cardiotoxicity. Neuraxial adjuvant such as clonidine used in epidural anesthesia offers advantage by augmenting the local anesthetic effect and reducing the anesthetic and analgesic requirement.

AIMS AND OBJECTIVES

Comparison of onset, duration of sensory and motor block, and any adverse effects between 0.5% ropivacaine with normal saline versus 0.5% ropivacaine with clonidine (75 μg/kg).

MATERIALS AND METHODS

This prospective randomized study was carried out in 50 patients (25 in each group) of American Society of Anesthesiologist Grade 1 and 2 scheduled for abdominal hysterectomy under epidural block. Group-1 (ropivacaine-clonidine [RC]): Epidural ropivacaine 20 ml (0.5%) with 0.75 μg/kg clonidine. Group-2 (ropivacaine [R]): Epidural ropivacaine 20 ml (0.5%) with normal saline. Onset, duration of sensory-motor block, heart rate, blood pressure, oxygen saturation, and respiratory rate were recorded.

STATISTICAL ANALYSIS

The statistical analysis was done using Statistical Package for Social Sciences version 15.0. Chi-square test, ANOVA, Student's t-test, and paired t-test were used.

RESULTS

Groups were comparable with regard to demographic data and hemodynamic stability. Onset of sensory and motor blockade was faster in RC group as compared to R group. Duration of postoperative analgesia was significantly prolonged in RC group. No potential side effect was seen in either group.

CONCLUSION

On account of faster onset, hemodynamic stability, and prolonged postoperative analgesia, ropivacaine with clonidine is a better option than ropivacaine alone.

Neuroprotective and anti-inflammatory effects of lidocaine in kainic acid-injected rats

Lidocaine, the most commonly used local anesthetic, inhibits glutamate release from nerve terminals. Given the involvement of glutamate neurotoxicity in the pathogenesis of various neurological disorders, this study investigated the role of lidocaine in hippocampal neuronal death and inflammatory events induced by an i.p. injection of kainic acid (KA) (15 mg/kg), a glutamate analog. The results showed that KA significantly led to neuronal death in the CA3 pyramidal layers of the hippocampus and this effect was attenuated by the systemic administration of lidocaine (0.8 or 4 mg/kg, i.p.) 30 min before KA injection. Moreover, KA-induced microglia activation and gene expression of proinflammatory cytokines, namely, interleukin-1β, interleukin-6, and tumor necrosis factor-α, in the hippocampus were reduced by the lidocaine pretreatment. Altogether, the results suggest that lidocaine can effectively treat glutamate excitotoxicity-related brain disorders.

Clinical usefulness of pectoral nerve block for the management of zoster-associated pain: case reports and technical description

The recently introduced pectoral nerve (Pecs) block is a simple alterative to the conventional thoracic paravertebral block or epidural block for breast surgery. It produces excellent analgesia and can be used to provide balanced anesthesia and as a rescue block in cases where performing a neuraxial blockade is not possible. In the thoracic region, a neuraxial blockade is often used to manage zoster-associated pain. However, this can be challenging for physicians due to the increased risk of hemodynamic instability in the upper thoracic level, and comorbid and contraindicated medical conditions such as coagulopathy. Here, we introduce an ultrasound-guided Pecs block for the management of herpes zoster-associated pain, which could be an effective alternative to other interventional options in the thoracic region.

Topical Nasal Anesthesia in Flexible Bronchoscopy--A Cross-Over Comparison between Two Devices

Introduction

Topical airway anesthesia is known to improve tolerance and patient satisfaction during flexible bronchoscopy (FB). Lidocaine is commonly used, delivered as an atomized spray. The current study assesses safety and patient satisfaction for nasal anesthesia of a new atomization device during outpatient bronchoscopy in lung transplant recipients.

Methods

Using a prospective, non-blinded, cross-over design, patients enrolled between 01-10-2014 and 24-11-2014 received 2% lidocaine using the standard reusable nasal atomizer (CRNA). Those enrolled between 25-11-2014 and 30-01-2015, received a disposable intranasal mucosal atomization device (DIMAD). After each procedure, the treating physician, their assistant and the patient independently rated side-effects and satisfaction, basing their responses on visual analogue scales (VAS). At their next scheduled bronchoscopy during the study period, patients then received the alternative atomizer. Written consent was obtained prior to the first bronchoscopy, and the study approved by the institutional ethics committee.

Results

Of the 252 patients enrolled between 01-10-2014 and 30-01-2015, 80 (32%) received both atomizers. Physicians reported better efficacy (p = 0.001) and fewer side effects (p< = 0.001) for DIMAD in patients exposed to both procedures. Among patients with one visit, physicians and their assistants reported improved efficacy (p = 0.018, p = 0.002) and fewer side effects (p< = 0.001, p = 0.029) for the disposable atomizer, whereas patients reported no difference in efficacy or side effects (p = 0.72 and p = 0.20). No severe adverse events were noted. The cost of the reusable device was 4.08€ per procedure, compared to 3.70€ for the disposable device.

Discussion

Topical nasal anesthesia via a disposable intranasal mucosal atomization device (DIMAD) offers comparable safety and patient comfort, compared to conventional reusable nasal atomizers (CRNA) in lung transplant recipients. Procedural costs were reduced by 0.34€ per procedure.

Trial Registration

clinicaltrials.gov NCT02237651

Lidocaine-induced methemoglobinemia: a clinical reminder

Methemoglobinemia is a rare condition in which the iron in hemoglobin is stabilized in the ferric (Fe(3+)) form, making it unable to bind oxygen and leading to tissue hypoxia and possibly death. The condition may be hereditary or acquired, the latter resulting from ingestion or application of common oxidizing agents such as lidocaine. As management of methemoglobinemia depends on prompt recognition, clinicians who administer or prescribe oxidizing agents must be aware of the clinical symptoms of methemoglobinemia, including cyanosis, pulse oximetry values that do not respond to increased oxygen delivery, and altered mental status. Currently, methylene blue is the drug of choice for the management of methemoglobinemia.

Isoflurane versus sevoflurane with interscalene block for shoulder arthroscopic procedures: Value of process capability indices as an additional tool for data analysis

BACKGROUND AND AIMS

Hypotensive anaesthesia reduces intra-articular bleed and promotes visualisation during arthroscopy. The haemodynamic effects of inhalational agents isoflurane and sevoflurane were studied extensively, and both were found to reduce mean arterial pressures (MBP) to an equivalent magnitude. We investigated the relative ability of isoflurane vis-a-vis sevoflurane to maintain the target systolic blood pressure (SBP) in patients undergoing shoulder arthroscopic procedures.

METHODS

In a prospective randomised study, 59 patients in two groups of 30 and 29 patients each received concomitant general anaesthesia (1.2-1.5 MAC of isoflurane and sevoflurane) and interscalene brachial plexus block. Nitrous oxide was used in both groups. Intraoperatively, serial blood pressure recordings of SBP, diastolic blood pressure (DBP), MBP and heart rates were done at every 3^rd min intervals. The manipulations needed to achieve target SBP (T = 90 mmHg) for optimal arthroscopic visualisation and treat unacceptable hypotensive episodes were noted. Conventional statistical tests and process capability index (PCI) evaluation were both deployed for data analysis.

RESULTS

Lower mean SBP and DBPs were recorded for isoflurane patients as compared to sevoflurane (P < 0.05, for mean, maximum and minimum recordings). Higher mean heart rates were recorded for isoflurane (P < 0.05). PCIs indicated that isoflurane was superior to sevoflurane in the ease of achieving target SBP of 90 mmHg as well as maintaining blood pressures in the range of 80-100 mmHg.

CONCLUSION

Isoflurane provides better intraoperative haemodynamic status vis-a-vis sevoflurane in patients undergoing shoulder arthroscopic surgery with preliminary interscalene blockade. The PCI can be a useful additional medical data analysis tool.

A Randomized Trial of 1% vs 2% Lignocaine by the Spray-as-You-Go Technique for Topical Anesthesia During Flexible Bronchoscopy

BACKGROUND

The optimal concentration of lignocaine to be used during flexible bronchoscopy (FB) remains unknown. This randomized controlled trial compared the efficacy and safety of 1% and 2% lignocaine solution for topical anesthesia during FB.

METHODS

Consecutive patients were randomized to receive either 1% or 2% lignocaine solution through the bronchoscope by the "spray-as-you-go" technique. The primary outcome of the study was the assessment of cough by the operator and the patient using the visual analog scale (VAS) and pain assessment using the faces pain rating scale. The secondary outcomes included total lignocaine dose, oxygenation status, adverse reactions related to lignocaine, and others.

RESULTS

Five hundred patients were randomized (median age, 51 years; 71% men) 1:1 to either group. The median operator VAS score for cough was significantly higher (25 vs 21, P = .015) in the 1% group; however, the patient VAS score was not significantly different (32 vs 27, P = .065). The pain rating was similar between the two groups. The median cumulative dose of lignocaine was significantly higher in the 2% group (397 mg vs 312 mg, P = .0001; 7.1 mg/kg vs 5.7 mg/kg, P = .0001). About 28% of patients in the 2% group exceeded the maximum recommended dose (> 8.2 mg/kg) of lignocaine. No adverse event related to lignocaine overdose was seen in either group.

CONCLUSIONS

One percent lignocaine was found to be as effective as 2% solution for topical anesthesia during FB, albeit at a significantly lower dose as the latter. Thus, 1% lignocaine should be the preferred concentration for topical anesthesia during FB.

TRIAL REGISTRY

ClinicalTrials.gov; No.: NCT01955824; URL: www.clinicaltrials.gov.