Palatal needle-free anesthesia for upper molars extraction. A randomized clinical trial

BACKGROUND

The aim of this study was to compare the ability of liposomal and non-liposomal lidocaine and prilocaine in hydrogel formulations to promote topical anesthesia in palatal mucosa during upper molar extractions.

METHODS

In this randomized, cross over, triple-blinded clinical trial, a liposomal and a non-liposomal formulation of the eutectic mixture of local anesthetics, 2.5% lidocaine and 2.5% prilocaine, were used to promote palatal anesthesia without the local anesthetic infiltration during bilateral upper molars extractions.

RESULTS

From the total of 40 patients included in this study, the non-liposomal eutectic lidocaine-prilocaine formulation failed in 40% of cases, unlike the liposomal formulation, which was effective for all patients (Fisher's exact test, p < 0.0001). Furthermore, the liposomal formulation (26.75 ± 7,47 min) induced longer anesthesia duration (t-test, p < 0.0001) than the non-liposomal formulation (16.78 ± 4.75 min). No mucosal ulceration or discomfort was reported for both formulations.

CONCLUSION

The liposomal formulation was able to induce adequate anesthesia in palatal mucosa during dental extraction, avoiding the local anesthetic infiltration. For the first time, a topical formulation allowed upper molars surgical removal without injection of any local anesthetic agent into palatal mucosa in adults.

Observational study of adverse reactions related to articaine and lidocaine

PURPOSE

This study determined the frequency of adverse reactions related to the administration of local dental anesthesia with 4% articaine compared with 2% lidocaine, both associated with epinephrine 1:100,000. The null hypothesis was that there is no difference between the administrations of both dental local anesthesia.

METHODS

From a total of 727 patients in an emergency service, 338 and 389 patients were subjected to local anesthesia with lidocaine and articaine, respectively. A questionnaire was completed for each patient that contained patient data, the local anesthesia applied, and any reactions.

RESULTS

The overall frequency of adverse reactions was 3.71%, with sweating and pallor being the most frequently observed. There was an association between adverse reactions and the use of daily medication by patients anesthetized with articaine (p = 0.0266). In contrast, in patients anesthetized with lidocaine, there was an association among the duration of the procedure (p = 0.0423), the type of procedure (p = 0.0146), and first anesthesia exposure (p = 0.0448).

CONCLUSIONS

The low frequency of adverse reactions with use of articaine and lidocaine led to the conclusion that both solutions are safe for use in dentistry.

[Influence of different local anesthetics on atracurium neuromuscular blockade on rats]

INTRODUCTION

The association between Local Anesthetics (LAs) and Neuromuscular Blocking (NMB) drugs in clinical practice, and the possibility of interaction between these drugs has been investigated. LAs act on neuromuscular transmission in a dose-dependent manner and may potentiate the effects of NMB drugs.

OBJECTIVE

The aim of this study was to evaluate, in an experimental model, the effect of lidocaine and racemic bupivacaine on neuromuscular transmission and the influence on neuromuscular blockade produced by atracurium.

METHODS

Male Wistar rats, weighing from 250 g to 300g were used. The preparation was set up based on a technique proposed by Bülbring. Groups were formed (n = 5) according to the drug studied: lidocaine 20 μg.mL^-1 (Group I); racemic bupivacaine 5 μg.mL^-1 (Group II); atracurium 20 μg.mL^-1 (Group III); atracurium 20 μg.mL^-1 in a preparation previously exposed to lidocaine 20 μg.mL^-1 and racemic bupivacaine 5 μg.mL^-1, Groups IV and V, respectively. The following parameters were assessed: 1) Amplitude of hemi diaphragmatic response to indirect stimulation before and 60 minutes after addition of the drugs; 2) Membrane Potentials (MP) and Miniature Endplate Potentials (MEPPs).

RESULTS

Lidocaine and racemic bupivacaine alone did not alter the amplitude of muscle response. With previous use of lidocaine and racemic bupivacaine, the neuromuscular blockade (%) induced by atracurium was 86.66 ± 12.48 and 100, respectively, with a significant difference (p = 0.003), in comparison to the blockade produced by atracurium alone (55.7 ± 11.22). These drugs did not alter membrane potential. Lidocaine initially increased the frequency of MEPPs, followed by blockade. With the use of bupivacaine, the blockade was progressive.

CONCLUSIONS

Lidocaine and racemic bupivacaine had a presynaptic effect expressed by alterations in MEPPs, which may explain the interaction and potentiation of NMB produced by atracurium.

Differential effects and mechanisms of local anesthetics on esophageal carcinoma cell migration, growth, survival and chemosensitivity

Background

Retrospective analysis and pre-clinical studies suggest that local anesthetics have anti-tumoral effects. However, the association between cancer recurrence and the use of local anesthesia is inconclusive and most reports are based on single local anesthetic results.

Methods

The biological effects (growth, migration and survival) of four common local anesthetics on esophageal carcinoma cells were compared. Biochemical assays on molecules involved in cell migration and proliferation were analyzed.

Results

Ropivacaine and bupivacaine significantly inhibited esophageal carcinoma cell migration, at clinically relevant micromolar concentrations. Mepivacaine and lidocaine showed less potent cell migration inhibition than ropivacaine or bupivacaine. All four local anesthetics inhibited cell proliferation. Of note, the effective concentration of anti-proliferative activities requires higher doses. At millimolar concentrations of these local anesthetics, cell apoptosis was moderately affected. Drug combination analysis demonstrated that two of four local anesthetics augmented chemotherapeutic drugs in inhibiting migration. However, all four local anesthetics significantly augmented chemotherapeutic drugs in inhibiting growth and inducing apoptosis. The anti-growth and anti-survival effects of four local anesthetics were attributed to mitochondrial dysfunction and oxidative damage. The anti-migratory effect of local anesthetics is likely through decreasing Rac1 activity.

Conclusions

Our work demonstrates the differential effects and proposes the mechanisms of local anesthetics on esophageal carcinoma cell migration, growth, survival and chemosensitivity.

Postherpetic Neuralgia: Current Evidence on the Topical Film-Forming Spray with Bupivacaine Hydrochloride and a Review of Available Treatment Strategies

PURPOSE OF REVIEW

This is a comprehensive review of the literature about the use of bupivacaine hydrochloride for the treatment of post-herpetic neuralgia (PHN). It briefly reviews the background, biology, diagnosis and conventional treatment for PHN, and then introduces and compares the recent evidence for the use of topical bupivacaine.

RECENT FINDINGS

PHN is defined by pain lasting 90 days or more after the initial presentation of herpes zoster ("Shingles", HZ) rash and is the most common complication of this disease. A product of re-activation of the Varicella-Zoster virus (VZV), HZ is diagnosed more than 1 million times annually in the United States. Approximately 20% of patients with HZ will experience PHN and will continue to suffer intermittent neuropathic symptoms, including itching and pain, that is sharp, stabbing, throbbing or burning, with the pain localized to the site of their original rash. This long-lasting pain compares with the severity of long-standing rheumatics and osteo-arthritis and is accompanied by severe allodynia causing significant suffering, and a financial burden that is manifested in both healthcare costs and loss of quality-adjusted life years. Prevention of PHN may be achieved with the Zoster vaccine, although there is still a large segment of unvaccinated population. Moreover, the Zoster vaccine is not always effective for prevention. Current treatment includes medical (systemic tricyclic antidepressants, anticonvulsants and opioids, topical lidocaine and capsaicin) and interventional (subcutaneous Botox injections, nerve blocks and nerve stimulation) therapies. These therapies are not always effective, and each carries their own profile of side effects and risks. Moreover, up to 50% of patients with PHN are refractory to management. Recent evidence is emerging to support the use of topical local anesthetics for the treatment of PHN. Two small studies recently found topical lidocaine spray to be effective in treating paroxysmal pain attacks associated with PHN. Bupivacaine is a longer-lasting local anesthetic, and a film-forming formulation allows easy and durable application to the affected skin. Recent studies show that topical film-forming bupivacaine is safe and as effective as lidocaine for the treatment of PHN. PHN is an important though common complication of HZ and can cause long-lasting pain and disability. Current treatment for PNH is limited by efficacy and safety profiles of individual therapies. Recent evidence points to topical local anesthetics as an effective and safe alternative to conventional therapy. Film-forming bupivacaine may offer a durable and safe option for this otherwise difficult to treat syndrome.

Effects of local anesthetics on cancer cells

Local anesthetics are widely used during clinical cancer surgeries. Studies have suggested that the use and the type of anesthesia affect cancer outcomes. In vivo studies and clinical data show that the use of local anesthetics is potentially beneficial for cancer treatment. However, the effect of the use of local anesthetics on the survival rate of cancer patients following surgery is controversial and, so far, little is known about the direct effects of local anesthetics on cancer cells. This work reviews and summarizes the published literature regarding the preclinical research methods and findings on the influence of local anesthetics on cancer cells. We hope that a thorough understanding of this subject will help to define optimal anesthetic regimens that lead to better outcomes for clinical cancer patients.

Prospective Comparative Analysis of the Incidence of Vasovagal Reaction and the Effect of Rectal Submucosal Lidocaine Injection in Stapled Hemorrhoidopexy: A Randomized Controlled Trial

Purpose

This study was performed to evaluate the incidence of vasovagal reactions (VVRs) and the efficacy of lidocaine injection for prevention.

Methods

One hundred seventeen patients diagnosed with hemorrhoids and scheduled to undergo a stapled hemorrhoidopexy (SH) were randomly divided according to submucosal injection to the rectum: lidocaine group (n = 53, lidocaine injected just before full closure of the stapler) and control group (n = 58). Outcomes included baseline patient characteristics (American Society of Anesthesiologists physical status classification, body mass index, diabetes mellitus, hypertension, and previous VVR history), vital signs during the operation, incidence of VVRs (hypotension, bradycardia, dizziness, diaphoresis, and nausea/vomiting), and postoperative complications (pain, bleeding, and urinary retention).

Results

Baseline characteristics were similar between groups. The number of patients with lower abdominal pain after firing the stapler and incidence of dizziness were lower for the lidocaine group than for the control group (9.4% vs. 25.9%, P = 0.017; 0% vs. 8.6%, P = 0.035, respectively). However, there were no significant between-group differences in incidence of nausea and diaphoresis (0% vs. 3.4%, P = 0.172) and syncope (1.9% vs. 3.4%, P = 0.612). Fewer patients in the lidocaine group complained of postoperative pain (41.5% vs. 58.6%, P = 0.072), and these patients used analgesics less frequently than those in the control group (28.3% vs. 36.2%, P = 0.374).

Conclusion

Patients who received a submucosal lidocaine injection prior to SH experienced less lower abdominal pain and dizziness compared with those who received standard treatment. A larger, more detailed prospective study is needed for further analysis.

Cytotoxicity of amide-linked local anesthetics on melanoma cells via inhibition of Ras and RhoA signaling independent of sodium channel blockade

BACKGROUND

Substantial clinical and preclinical evidence have indicated the association between amide-linked local anesthesia and the long-term outcomes of cancer patients. However, the potential effects of local anesthesia on cancer recurrence are inconclusive and the underlying mechanisms remain poorly understood.

METHODS

We systematically examined the effects of three commonly used local anesthetics in melanoma cells and analyzed the underlying mechanisms focusing on small GTPases.

RESULTS

Ropivacaine and lidocaine but not bupivacaine inhibited migration and proliferation, and induced apoptosis in melanoma cells. In addition, ropivacaine and lidocaine but not bupivacaine significantly augmented the in vitro efficacy of vemurafenib (a B-Raf inhibitor for melanoma with BRAF V600E mutation) and dacarbazine (a chemotherapeutic drug). Mechanistically, ropivacaine but not bupivacaine decreased the activities of Ras superfamily members with the dominant inhibitory effects on RhoA and Ras, independent of sodium channel blockade. Rescue studies using constitutively active Ras and Rho activator calpeptin demonstrated that ropivacaine inhibited migration mainly through RhoA whereas growth and survival were mainly inhibited through Ras in melanoma cells. We further detected a global reduction of downstream signaling of Ras and RhoA in ropivacaine-treated melanoma cells.

CONCLUSION

Our study is the first to demonstrate the anti-melanoma activity of ropivacaine and lidocaine but not bupivacaine, via targeting small GTPases. Our findings provide preclinical evidence on how amide-linked local anesthetics could affect melanoma patients.

[General anesthesia combined with erector spinae plane block for ductus arteriosus closure: two case reports]

BACKGROUND

Failure of ductus arteriosus closure in preterm neonates results in a left-to-right shunt that leads to variable severities of hemodynamic and respiratory distress. When medical therapy fails, surgical ligation via left lateral thoracotomy remains an alternative approach and can be performed in the operating room or at the bedside with a low mortality rate. Opioid-based anesthesia is a frequent choice among anesthesiologists who manage patent ductus arteriosus cases based on the suppression of the stress response and maintenance of hemodynamic stability. This rationale suggests that regional anesthesia may also be an advantageous technique and may benefit earlier weaning from ventilation. Blocking afferent signals before incision may also modulate the long-term consequences of altered sensory perception and pain responses.

CASE REPORT

We present two cases of general anesthesia combined with erector spinae plane block as part of multimodal anesthesia in premature twins undergoing patent ductus arteriosus closure.

DISCUSSION

In these cases, the use of erector spinae plane block combined with general anesthesia was efficient to minimize the negative impact of surgery and allowed a reduction in the amount of intraoperative opioid use for patent ductus arteriosus closure.

Advances of Nano-Structured Extended-Release Local Anesthetics

Extended-release local anesthetics (LAs) have drawn increasing attention with their promising role in improving analgesia and reducing adverse events of LAs. Nano-structured carriers such as liposomes and polymersomes optimally meet the demands of/for extended-release, and have been utilized in drug delivery over decades and showed satisfactory results with extended-release. Based on mature technology of liposomes, EXPAREL, the first approved liposomal LA loaded with bupivacaine, has seen its success in an extended-release form. At the same time, polymersomes has advances over liposomes with complementary profiles, which inspires the emergence of hybrid carriers. This article summarized the recent research successes on nano-structured extended-release LAs, of which liposomal and polymeric are mainstream systems. Furthermore, with continual optimization, drug delivery systems carry properties beyond simple transportation, such as specificity and responsiveness. In the near future, we may achieve targeted delivery and controlled-release properties to satisfy various analgesic requirements.

[Ankle block]

OBJECTIVE

The so-called ankle block represents a local anesthesia form which enables easy performance of all surgical procedures of the foot and ankle.

INDICATIONS

Interventions distal to the medial and lateral malleoli.

CONTRAINDICATIONS

Acute and chronic infections in the area of injection; allergy to the local anesthesia.

SURGICAL TECHNIQUE

All five sensory foot nerves are blocked. The two deep lying nerves, the tibial nerve and the deep fibular nerve, can be directly anesthetized perineurally using anatomical landmarks. The other three nerves are subcutaneously infiltrated near their branches.

RESULTS

The success rate ranges from 88 to 94%; smaller areas may also be further blocked intraoperatively. The ankle block is a cost-effective procedure which can also be performed without problems in multimorbid patients due to its minor side effects.

Recent advances in polymer-based drug delivery systems for local anesthetics

Local anesthetics, which cause temporary loss of pain by inhibiting the transmission of nerve impulses, have been widely used in clinical practice. However, neurotoxicity and short half-lives have significantly limited their clinical applications. To overcome those barriers, numerous drug delivery systems (DDS) have been designed to encapsulate local anesthetic agents, so that large doses can be released slowly and provide analgesia over a prolonged period. So far, multiple classes of local anesthetic carriers have been investigated, with some of them already on the market. Among those, polymer-based delivery platforms are the most extensively explored, especially in the form of polymeric nanoparticle carriers. This review gives a specific focus on the most commonly used natural and synthetic polymers for local anesthetics delivery, owing to their excellent biocompatibility, biodegradability and versatility. State-of-the-art studies concerning such polymer delivery systems have been discussed in depth. We also highlight the impact of those delivery platforms as well as some key challenges that need to be overcome for their broader clinical applications. STATEMENT OF SIGNIFICANCE: Currently, local anesthetics have been widely used in clinically practices to prevent transmission of nerve impulses. However, the applications of anesthetics are greatly limited due to their neurotoxicity and short half-lives. Moreover, it is difficult to maintain frequent administrations which can cause poor compliance and serious consequences. Numerous drug delivery systems have been developed to solve those issues. In this review, we highlight the recent advances in polymer-based drug delivery systems for local anesthetics. The advantages as well as shortcomings for different types of polymer-based drug delivery systems are summarized in this paper. In the end, we also give prospects for future development of polymer drug delivery systems for anesthetics.

Overlay of a sponge soaked with ropivacaine and multisite infiltration analgesia result in faster recovery after laparoscopic hepatectomy

BACKGROUND

Compared with traditional open surgery, laparoscopic surgery is preferred due to the advantages of less trauma, less pain, and faster recovery. Nevertheless, many patients still suffer from postoperative pain resulting from the surgical incision and associated tissue injury. Many researchers have reported methods to improve postoperative pain control, but there is not a simple and effective method that can be clinically adopted in a widespread manner. We designed this study to prove the hypothesis that application of ropivacaine in the port site and operative site in patients is an effective and convenient method which can decrease postoperative pain and accelerate recovery.

AIM

To evaluate the effects of ropivacaine on pain control after laparoscopic hepatectomy and its contribution to patient recovery.

METHODS

From May 2017 to November 2018, 146 patients undergoing laparoscopic hepatectomy were randomized to receive infiltration of either 7.5 mg/mL ropivacaine around the trocar insertions, incision, and cutting surface of the liver (with a gelatin sponge soaked with ropivacaine) at the end of surgery (ropivacaine group), or normal saline (5 mL) at the same sites at the end of surgery (control group). The degree of pain, nausea, vomiting, heart rate (HR), and blood pressure were collected. The length of postoperative hospitalization, complications, and the levels of stress hormones were also compared between the two groups.

RESULTS

Compared with the control group, the ropivacaine group showed reduced postoperative pain at rest within 12 h (P < 0.05), and pain on movement was reduced within 48 h. The levels of epinephrine, norepinephrine, and cortisol at 24 and 48 h, HR, blood pressure, and cumulative sufentanil consumption in the ropivacaine group were significantly lower than those in the control group (P < 0.05). In the ropivacaine group, hospitalization after operation was shorter, but the difference was not statistically significant. There were no significant differences in postoperative nausea, vomiting, or other complications, including hydrothorax, ascites, peritonitis, flatulence, and venous thrombus (P > 0.05), although fewer patients in the ropivacaine group experienced these situations.

CONCLUSION

Infiltration with ropivacaine in the abdominal wound and covering the cutting surface of the liver with a gelatin sponge soaked with ropivacaine significantly reduce postoperative pain and the consumption of sufentanil.

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.

Lipid-based carriers for the delivery of local anesthetics

INTRODUCTION

There is a clinical need for pharmaceutical dosage forms devised to prolong the acting time of local anesthetic (LA) agents or to reduce their toxicity. Encapsulation of LA in drug delivery systems (DDSs) can provide long-term anesthesia for inpatients (e.g. in immediate postsurgical pain control, avoiding the side effects from systemic analgesia) and diminished systemic toxicity for outpatients (in ambulatory/dentistry procedures). The lipid-based formulations described here, such as liposomes, microemulsions, and lipid nanoparticles, have provided several nanotechnological advances and therapeutic alternatives despite some inherent limitations associated with the fabrication processes, costs, and preclinical evaluation models.

AREAS COVERED

A description of the currently promising lipid-based carriers, including liposomes, microemulsions, and nanostructured lipid carriers, followed by a systematic review of the existing lipid-based formulations proposed for LA. Trends in the research of these LA-in-DDS are then exposed, from the point of view of administration route and alternatives for non-traditionally administered LA molecules.

EXPERT OPINION

Considering the current state and potential future developments in the field, we discuss the reasons for why dozens of formulations published every year fail to reach clinical trials; only one lipid-based formulation for the delivery of local anesthetic (Exparel®) has been approved so far.

Mechanism of local anesthetic-induced disruption of raft-like ordered membrane domains

BACKGROUND

Because ordered membrane domains, called lipid rafts, regulate activation of ion channels related to the nerve pulse, lipids rafts are thought to be a possible target for anesthetic molecules. To understand the mechanism of anesthetic action, we examined influence of representative local anesthetics (LAs); dibucaine, tetracaine, and lidocaine, on raft-like liquid-ordered (L_o)/non-raft-like liquid-disordered (L_d) phase separation.

METHODS

Impact of LAs on the phase separation was observed by fluorescent microscopy. LA-induced perturbation of the L_o and L_d membranes was examined by DPH anisotropy measurements. Incorporation of LAs to the membranes was examined by fluorescent anisotropy of LAs. The biding location of the LAs was indicated by small angle x-ray diffraction (SAXD).

RESULTS

Fluorescent experiments showed that dibucaine eliminated the phase separation the most effectively, followed by tetracaine and lidocaine. The disruption of the phase separation can be explained by their disordering effects on the L_o membrane. SAXD and other experiments further suggested that dibucaine's most potent perturbation of the L_o membrane is attributable to its deeper immersion and bulky molecular structure. Tetracaine, albeit immersed in the L_o membrane as deeply as dibucaine, less perturbs the L_o membrane probably because of its smaller bulkiness. Lidocaine hardly reaches the hydrophobic region, resulting in the weakest L_o membrane perturbation.

CONCLUSION

Dibcaine perturbs the L_o membrane the most effectively, followed by tetracaine and lidocaine. This ranking correlates with their anesthetic potency.

GENERAL SIGNIFICANCE

This study suggests a possible mechanistic link between anesthetic action and perturbation of lipid rafts.

Capsazepine prolongation of the duration of lidocaine block of sensory transmission in mice may be mediated by modulation of HCN channel currents

Background and objectives

Hyperpolarization-activation cyclic nucleotide-gated (HCN) channels contribute to the effects of lidocaine. Capsazepine (CPZ), a competitive inhibitor of capsaicin of transient receptor potential vanilloid-1 channel, has also been found to inhibit HCN channel currents (I _h). This study was designed to investigate whether CPZ could prolong durations of lidocaine in regional anesthesia.

Methods

Mouse HCN1 and HCN2 channels were expressed in human embryonic kidney 293 (HEK 293) cells. The effect of CPZ on I _h was measured by whole-cell patch-clamping recording. Sciatic nerve block model in mice was used for the study in vivo. The mice were randomly divided into seven groups, respectively, receiving lidocaine, CPZ, ZD7288 (HCN channel blocker), CPZ + lidocaine, ZD7288 + lidocaine, ZD7288 + CPZ + lidocaine, forskolin (an activator of adenylyl cyclase) + CPZ + lidocaine. Regional anesthetic durations of lidocaine were determined. Voltage-gated sodium channel currents (I _Na) and I _h were recorded in dorsal root ganglion neurons of mice. The effects of CPZ on I _Na and I _h with or without Cyclic adenosine monophosphate (cAMP) were assessed. Isolated mice sciatic nerve was prepared to evaluate the effect of CPZ on the compound action potentials (CAP).

Results

Capsazepine non-selectively inhibited transfected mHCN1 and mHCN2 channel currents in HEK 293 cells. In sciatic nerve block in vivo, compared to lidocaine alone, adding CPZ extended the durations of lidocaine for noxious sensory block (35.1 ± 3.3 vs. 20.3 ± 1.7 min), tactile sensory block (25.5 ± 4.4 vs. 20.0 ± 3.7 min), thermal sensory block (39.6 ± 6.6 vs. 26.8 ± 5.5 min), and motor function block (28.6 ± 4.1 vs. 20.9 ± 4.2 min). Duration of thermal sensory block was longer in CPZ + lidocaine group than that of ZD7288 + lidocaine group (39.6 ± 6.6 vs. 33.4 ± 4.5 min). Forskolin reversed the prolongation by CPZ on lidocaine durations. CPZ or ZD7288 alone did not produce typical regional anesthetic effects. Increased intracellular concentration of cAMP reversed the inhibition of CPZ on I _h. Although CPZ alone inhibited I _Na at the concentration more than 30 μM, it did not inhibit the CAP amplitudes in isolated sciatic nerves. CPZ dose-dependently enhanced the inhibitory effect of 1% lidocaine on the CAP amplitudes.

Conclusions

Capsazepine may prolong durations of lidocaine in peripheral nerve block by modulation of HCN channel currents.

Intraperitoneal nebulization versus intraperitoneal instillation of ropivacaine for postoperative pain management following laparoscopic donor nephrectomy

BACKGROUND

Laparoscopic donor nephrectomy is considered less painful than open nephrectomy but is still associated with significant postoperative pain. Studies reported that intraperitoneal instillation of local anesthetics provides uncertain pain relief after laparoscopic surgery. This randomized, double-blind study evaluated the effect of intraperitoneal nebulization of ropivacaine on postoperative pain relief after laparoscopic donor nephrectomy.

METHODS

Sixty patients undergoing elective laparoscopic donor nephrectomy were randomly assigned to receive either an instillation of 20 ml 0.5% ropivacaine after the induction of pneumoperitoneum or nebulization of 5 ml 1% ropivacaine before and after surgery. The primary outcome was the degree of pain relief (static and dynamic) after surgery. The secondary outcomes were postoperative fentanyl consumption, incidence of shoulder pain, unassisted walking and postoperative nausea and vomiting (PONV). Data were collected in the postanesthesia care unit (PACU) and at 6, 24, and 48 h after surgery.

RESULTS

Compared to patients in the instillation group, those in the nebulization group showed significant reductions in postoperative pain and fentanyl consumption, and none complained of significant shoulder pain (visual analog scale score ≥ 30 mm). Within 20 h of surgery, 13.3% of patients in the instillation group and 93.3% in the nebulization group started unassisted walking (absolute risk reduction, 38%; P = 0.001). In the nebulization group, PONV was significantly reduced in the PACU and at 6 h.

CONCLUSIONS

Intraperitoneal nebulization of ropivacaine reduced postoperative pain, fentanyl consumption, referred shoulder pain, and PONV while enabling earlier mobility without any difference in the length of hospital stay.

Clinically relevant concentrations of lidocaine inhibit tumor angiogenesis through suppressing VEGF/VEGFR2 signaling

BACKGROUND

Angiogenesis, the formation of blood vessel, is required for invasive tumor growth and metastasis. In this study, the effects of lidocaine, an amide-link local anesthetic, on angiogenesis and tumor growth were investigated.

METHODS

In vitro angiogenesis assays were conducted using human umbilical vascular endothelial cell (HUVEC). Essential molecules involved in vascular endothelial growth factor (VEGF) signaling were analyzed. Tumor angiogenesis was analyzed using in vivo mouse tumor model.

RESULTS

Lidocaine at clinically relevant concentrations inhibited angiogenesis. Lidocaine inhibited endothelial cell in vitro capillary network formation on Matrigel through interfering early stage of angiogenesis. In addition, lidocaine inhibited vascular endothelial growth factor (VEGF)-stimulated endothelial cell migration and proliferation without affecting cell adhesion. Lidocaine also induced endothelial cell apoptosis in the presence of VEGF. Lidocaine suppressed VEGF-activated phosphorylation of VEGF receptor 2 (VEGFR2), PLCγ-PKC-MAPK and FAK-paxillin in endothelial cells, demonstrating that VEGF, PLC, MAPK and FAK-paxillin suppression is associated with the antiangiogenic effect of lidocaine. Importantly, the in vitro observations were translatable to in vivo B16 melanoma mouse model. Lidocaine significantly inhibited tumor angiogenesis, leading to delay of tumor growth.

CONCLUSIONS

This study is the first to report that lidocaine acts as an angiogenesis inhibitor. The findings provide preclinical evidence into the potential mechanisms by which lidocaine may negatively affect cancer growth and metastasis.

Regional Catheters for Outpatient Surgery-a Comprehensive Review

PURPOSE OF REVIEW

This review summarizes and discusses the history of continuous catheter blockade (CCB), its current applications, clinical considerations, economic benefits, potential complications, patient education, and best practice techniques.

RECENT FINDINGS

Regional catheters for outpatient surgery have greatly impacted acute post-operative pain management and recovery. Prior to development, options for acute pain management were limited to the use of opioid pain medications, NSAIDS, neuropathic agents, and the like as local anesthetic duration of action is limited to 4-8 h. Moreover, delivery of opioids post-operatively has been associated with respiratory and central nervous depression, development of opioid use disorder, and many other potential adverse effects. CCB allows for faster recovery time, decreased rates of opioid abuse, and better pain control in patients post-operatively. Outpatient surgical settings continue to focus on efficiency, quality, and safety, including strategies to prevent post-operative nausea, vomiting, and pain. Regional catheters are a valuable tool and help achieve all of the well-established endpoints of enhanced recovery after surgery (ERAS). CCB is growing in popularity with wide indications for a variety of surgeries, and has demonstrated improved patient satisfaction, outcomes, and reductions in many unwanted adverse effects in the outpatient setting.

Ropivacaine inhibits pressure-induced lung endothelial hyperpermeability in models of acute hypertension

AIMS

Increases in hydrostatic pressure results in endothelial hyperpermeability via eNOS-dependent pathways. Ropivacaine is known to inhibit eNOS activation and to attenuate lung injury. Herein, we sought to determine if ropivacaine regulates pressure-induced lung endothelial hyperpermeability.

MAIN METHODS

The effects of ropivacaine on lung permeability were assessed in two models of acute hypertension (AH): the isolated perfused lung preparation where acute increases in left atrial pressure model the hemodynamic changes of severe hypertension, and an animal model of AH induced by norepinephrine. In the IPL model, whole lung filtration coefficient (K_f) was used as the index of lung permeability; pulmonary artery pressure (P_pa), pulmonary capillary pressures (P_pc), and zonal characteristics (ZC) were measured to assess the effects of ropivacaine on hemodynamics and their relationship to K_f2/K_f1. In vivo, ropivacaine effects were investigated on indices of pulmonary edema (changes in P_aO_2, lung wet-to-dry ratio), changes in plasma volume and nitric oxide (NO) production.

KEY FINDINGS

Ropivacaine provided robust protection from pressure-dependent barrier failure; it inhibited pressure-induced increases in K_f without affecting P_pa, P_pc or ZC. In vivo, ropivacaine prevented pressure-induced lung edema and associated hyperpermeability as evidence by maintaining P_aO₂, lung wet-to-dry ratio and plasma volume in levels similar to sham rats. Ropivacaine inhibited pressure-induced NO production as evidenced by decreased lung nitro-tyrosine content when compared to hypertensive lungs.

SIGNIFICANCE

Collectively these data show that ropivacaine inhibits pressure-induced lung endothelial hyperpermeability and suggest that ropivacaine may be a clinically useful agent to prevent endothelial hyperpermeability when pulmonary pressure is acutely increased.

The effect of local anesthetic continuous wound infusion for the prevention of postoperative pneumonia after on-pump cardiac surgery with sternotomy: the STERNOCAT randomized clinical trial

PURPOSE

Postoperative pain after cardiac surgery, exacerbated by cough and sternal mobilization, limits clearance of bronchopulmonary secretions and may predispose to postoperative pneumonia. In this study, we tested the ability of local anesthetic continuous wound infusion to prevent pneumonia after cardiac surgery with sternotomy and cardiopulmonary bypass (CPB) owing to better analgesia and bronchopulmonary drainage.

METHODS

In this randomized, double-blind, placebo-controlled trial conducted in five academic centers, patients undergoing cardiac surgery with sternotomy and CPB were enrolled from February 2012 until November 2014, and were followed over 30 days. Patients were assigned to a 48-h infusion (10 ml h^-1) of L-bupivacaine (12.5 mg h^-1) or placebo (saline) via a pre-sternal multiperforated catheter. Anesthesia and analgesia protocols were standardized. The primary end point was the incidence of pneumonia during the study period, i.e., until hospital discharge or 30 days. We hypothesized a 30% reduction in the incidence of pneumonia.

RESULTS

Among 1493 randomized patients, 1439 completed the trial. Pneumonia occurred in 36/746 patients (4.9%) in the L-bupivacaine group and in 42/739 patients (5.7%) in the placebo group (absolute risk difference taking into account center and baseline risk of postoperative pneumonia, - 1.3% [95% CI - 3.4; 0.8] P = 0.22). In the predefined subgroup of patients at high risk, L-bupivacaine decreased the incidence of pneumonia (absolute risk difference, - 5.6% [95% CI - 10.0; - 1.1], P = 0.01).

CONCLUSIONS

After cardiac surgery with sternotomy, continuous wound infusion of L-bupivacaine failed to decrease the incidence of pneumonia. These findings do not support the use of local anesthetic continuous wound infusion in this indication. Further study should investigate its effect in high-risk patients.

TRIAL REGISTRATION

EudraCT Number: 2011-003292-10; Clinicaltrials.gov Identifier: NCT01648777.

[Perioperative allergy. A 3-year experience]

BACKGROUND

Perioperative hypersensitivity reactions constitute a global health problem, with an estimated incidence of 1 per 100,000 procedures and a mortality rate of 0.1 to 9 %. Main risk factors are a history of allergy to other drugs, atopy, associated psychiatric disorders and previous surgeries.

OBJECTIVES

To determine the frequency of sensitization and the type of drugs involved in perioperative allergy in a tertiary care hospital, over a 3-year period.

METHODS

Retrospective, cross-sectional, descriptive study of perioperative allergy, corroborated by skin tests for each drug and latex, of patients treated at the Allergy and Clinical Immunology Department of Hospital General de Mexico.

RESULTS

Twenty-eight patients diagnosed with perioperative allergy were included. Main triggers were neuromuscular blocking agents (46.42 %), latex (28.52 %) and propofol (14.28 %). The main risk factor was a history of previous surgeries (89.28 %). Most perioperative allergic reactions were mild (71.42 %) and occurred within the postoperative period (60.71 %).

CONCLUSIONS

Initial diagnosis and Treatment should always be carried out by the anesthesiologist or surgeon, who should focus on the withdrawal of possible causative agents.

The analgesic efficacy of the continuous adductor canal block compared to continuous intravenous fentanyl infusion with a single-shot adductor canal block in total knee arthroplasty: a randomized controlled trial

Background

The adductor canal block (ACB) is an effective intervention for postoperative analgesia following total knee arthroplasty (TKA). However, the ideal ACB regimen has not yet been established. We compared the analgesic effects between a continuous ACB group and fentanyl-based intravenous patient-controlled analgesia (IV-PCA) with a single-shot ACB group.

Methods

Patients who underwent TKA were randomly allocated to either a continuous ACB group (Group CACB) or IV-PCA with a single-shot ACB group (Group IVACB). Before the surgery, ultrasound guided ACB with 0.5% ropivacaine 20 cc was provided to all patients. Before skin incision, the infusion system (0.2% ropivacaine through an adductor canal catheter in group CACB vs. intravenous fentanyl in group IVACB) was connected. The postoperative pain severity; the side effects of local anesthetics and opioids; administration of rescue analgesics and anti-emetics; and sensorimotor deficits were measured.

Results

Postoperative pain severity was significantly higher in the IVACB group at 30 min, 4 h, 24 h, and 48 h after surgery. The averages and standard deviations (SD) of the NRS score of postoperative pain were 0.14 ± 0.37, 4.57 ± 2.37, 6.00 ± 1.63, and 4.28 ± 1.49, respectively in the IVACB group. Rescue analgesic requirements and quadriceps muscle strength were not statistically different between the groups throughout the postoperative period. Moreover, rescue antiemetic requirements were higher in group IVACB than group CACB.

Conclusions

In this study, the continuous ACB provided superior analgesia and fewer side effects without any significant motor deficit than the IV-PCA with a single-shot ACB.

Effect of clonidine on the cutaneous silent period during spinal anesthesia

AIM

To investigate the effect of clonidine on the cutaneous silent period (CSP) during spinal anesthesia.

METHODS

A total of 67 adult patients were included in this randomized, prospective, single-center, double-blind trial. They did not have neurological disorders and were scheduled for inguinal hernia repair surgery. This trial was registered on ClinicalTrials.gov (NTC03121261). The patients were randomized into two groups with regards to the intrathecally administered solution: (1) 15 mg of 0.5% levobupivacaine with 50 µg of 0.015% clonidine, or (2) 15 mg of 0.5% levobupivacaine alone. There were 34 patients in the levobupivacaine-clonidine (LC) group and 33 patients in the levobupivacaine (L) group. CSP and its latency were measured four times: prior to the subarachnoid block (SAB), after motor block regression to the 0 level of the Bromage scale, with ongoing sensory blockade, and both 6 and 24 h after SAB.

RESULTS

Only data from 30 patients in each group were analyzed. There were no significant differences between the groups investigated preoperatively and after 24 h. The CSP of the L group at the time point when the Bromage scale was 0 was 44.8 ± 8.1 ms, while in the LC group it measured 40.2 ± 3.8 ms (P = 0.007). The latency in the L group at the time point when the Bromage scale was 0 was 130.3 ± 10.2 ms, and in the LC group it was 144.7 ± 8.3 ms (P < 0.001). The CSP of the L group after 6 h was 59.6 ± 9.8 ms, while in the LC group it was 44.5 ± 5.0 ms (P < 0.001). The latency in the L group after 6 h was 110.4 ± 10.6 ms, while in LC group it was 132.3 ± 9.7 ms (P < 0.001).

CONCLUSION

Intrathecal addition of clonidine to levobupivacaine for SAB in comparison with levobupivacaine alone results in a diminished inhibitory tonus and shortened CSP.