Randomized Trial of Buffered Versus Plain Lidocaine for Local Anaesthesia in open Carpal Tunnel Decompression

Carpal tunnel release under wide awake local anesthesia with no tourniquet in hemodialysis patients with arteriovenous shunt

INTRODUCTION

Long-term hemodialysis patients experience many hand diseases caused by dialysis-related amyloidosis (DRA), with carpal tunnel syndrome (CTS) being the most common. For the patients with arteriovenous (AV) shunt, surgical decompression remains challenging because of the contraindications of a tourniquet. A technique called wide-awake local anesthesia with no tourniquet (WALANT), in which epinephrine provides hemostasis instead of the tourniquet, can be a good option for hemodialysis patients. The purpose of this study was to assess the prevalence of CTS and related factors in hemodialysis patients, and to establish the efficacy and safety of WALANT on hemodialysis patients with AV shunt.

MATERIALS AND METHODS

This prospective study included 275 hemodialysis patients between March 2013 and July 2019. 43 patients were diagnosed with CTS, involving surgical treatment on 70 wrists. We performed mini-open carpal tunnel release using WALANT on the AV shunt arm (defined as the WALANT group), while using lidocaine and a tourniquet on the arm without an AV shunt (defined as the tourniquet group). The operative time, surgical field bleeding (blood loss and hemostasis score), surgical pain (injection pain and tourniquet pain), outcomes, complications, and satisfaction were compared between the two groups.

RESULTS

The incidence of CTS in hemodialysis patients was 15.6%. Longer dialysis durations were related to higher proportions of patients with CTS. There was no significant difference in blood loss (p=0.184) and hemostasis score (p=0.165) between the two groups. Clinical symptoms improved in all patients, and there were no severe complications. The WALANT group had a significantly longer preparation time of approximately 20minutes, but they had low injection pain and no tourniquet pain. There was also no significant difference in terms of satisfaction levels (p=0.212).

DISCUSSION

CTS is a very common disease among hemodialysis patients. WALANT provided sufficient hemostasis without a tourniquet, despite the patients' high bleeding tendency. The technique also had the advantages of low injection pain, no tourniquet pain, and no major complications. In this respect, WALANT can be a good choice for hemodialysis patients with AV shunt.

LEVEL OF EVIDENCE

II.

A randomized controlled trial of minor hand surgeries comparing wide awake local anesthesia no tourniquet and local anesthesia with tourniquet

INTRODUCTION

Epinephrine and sodium bicarbonate (NaHCO₃) used in wide-awake local anesthesia no tourniquet (WALANT) affect many areas such as hemostasis, injection pain, anesthetic effect and others. However, few clinical trials have focused on injection pain and the duration of anesthetic effect, and no prospective studies have reported the benefits of WALANT post operation. This study compared WALANT with conventional local anesthesia with tourniquet in minor hand surgeries, and aimed to answer following questions: (1) Does WALANT have enough benefits for injection pain and duration of anesthetic effect?; (2) How does WALANT affect postoperative management (such as postoperative pain and use of analgesics)?; (3) How satisfied are the patients with the surgery?

HYPOTHESIS

We hypothesized that WALANT had advantages in injection pain, duration of anesthetic effect, and postoperative management compared to conventional local anesthesia.

MATERIALS AND METHODS

The present study is designed as a randomized prospective one center study. This study included 185 patients who received surgical treatment for the diagnosis of carpal tunnel syndrome, trigger finger, or de Quervain's disease between 2017 and 2019. We randomly allocated the patients to either the WALANT group or the conventional group. We inquired and recorded patients' injection pain, duration of anesthetic effect, postoperative pain, the use of analgesics, and satisfaction with the surgery.

RESULTS

The injection pain was significantly lower in the WALANT group in all procedures (p<0.001). The duration of anesthetic effect was significantly longer in the WALANT group in all procedures (p<0.001). As for the postoperative management of all procedures, the pain score was significantly lower in the WALANT group until the first day after surgery, with the biggest difference at 6hours after surgery. The use of analgesics was significantly lower in the WALANT group until the second day after surgery. Satisfaction with surgery was significantly higher in the WALANT group in all procedures: A1 pulley release (p=0.026), 1st extensor retinaculum (p=0.045), and carpal tunnel release (p=0.003).

DISCUSSION

Our study showed better results in WALANT than in the conventional method, with no tourniquet pain, lower injection pains, longer anesthetic duration, and less postoperative pain. It provided patients with great satisfaction. In addition, WALANT has the potential benefits of no time limit due to tourniquet pain and long anesthetic effect. Therefore, WALANT is comfortable and cost effective, and could be a good alternative to conventional local lidocaine anesthesia.

LEVEL OF EVIDENCE

II.

"Sodium bicarbonate": an adjunct to painless palatal anesthesia

PURPOSE

It is believed that whenever we inject local anesthesia into the palate it is a painful experience for the patients. The aim of this study was to make palatal anesthesia painless by adding 7.4% sodium bicarbonate as an adjunct in local anesthesia.

METHODS

Fifty subjects requiring extraction of maxillary bilateral premolar teeth for orthodontic purpose free from periapical infections. These extractions were divided in such a way that all right-sided extractions were done under 2% lignocaine with 1:80,000 adrenaline; and all left-sided extractions were done under 2% lignocaine with 1:80,000 adrenaline with 7.4% sodium bicarbonate added. All extractions were performed using a consistent intra-alveolar technique by a single operator. Both the patient and the operator were blinded to the contents of the local anesthetic solution. Data records of these patients were procured on the basis of VAS and VRS, requirement of repeated injection, and onset and duration of anesthesia.

RESULTS

Clinical and statistical data confirmed that the addition of sodium bicarbonate in local anesthetics reduces pain and decreased the onset and increased duration of local anesthesia in the palatal site, as compared to injection of local anesthetic without sodium bicarbonate.

CONCLUSION

Effect of sodium bicarbonate on reducing pain while injecting into the palatal aspect was noted in this study.

Management of an Acute Exacerbation of Chronic Neuropathic Pain in the Emergency Department: A Case to Support Ultrasound-Guided Forearm Nerve Blocks

BACKGROUND

Acute on chronic neuropathic pain is often refractory to analgesics and can be challenging to treat in the emergency department (ED). In addition, systemic medications such as opiates and nonsteroidal inflammatory drugs have risks, including hypotension and kidney injury, respectively. Difficulties in managing pain in patients with neuropathy can lead to prolonged ED stays, undesired admissions, and subsequent increased health care costs.

CASE REPORT

We describe the case of a 51-year-old woman who presented to the ED on two separate occasions for left forearm pain secondary to chronic ulnar neuropathy. During her first ED visit, the patient received multiple rounds of intravenous opiates and required hospital admission, which was complicated by opiate-induced hypotension. During her second visit, she underwent an ultrasound-guided ulnar nerve block performed by the emergency physician; her pain resolved and she was discharged home. WHY SHOULD EMERGENCY PHYSICIANS BE AWARE OF THIS?: Ultrasound-guided nerve blocks are an effective, safe, and relatively inexpensive alternative to opioids. Our case demonstrates that emergency providers may be able to perform ultrasound-guided regional anesthesia to treat an acute exacerbation of chronic neuropathic pain.

The Use of a Fine-Gauge Needle to Reduce Pain in Open Carpal Tunnel Decompression: A Randomized Controlled Trial

This randomized controlled study on 86 patients compared the level of pain experienced by patients on instillation of local anaesthetic into the palm with a 23-gauge and a 27-gauge (dental) needle in open carpal tunnel decompression. Patients were asked to score the amount of pain they experienced during the injection of the local anaesthetic and their level of anxiety about future injections using a visual analogue scale (VAS) and a four-point verbal response scale (VRS). The mean pain and anxiety scores on the VAS were significantly lower in the dental needle group. There was significant correlation between the pain and anxiety VAS scores. When infiltrating local anaesthetic into the palm for open carpal tunnel decompression, the use of a fine (dental) needle can reduce the pain on that occasion and the anxiety concerning future injections likely to be experienced by the patient.

Pain Levels after Local Anaesthetic with or without Hyaluronidase in Carpal Tunnel Release: A Randomised Controlled Trial

Purpose. Hyaluronidase is an enzyme that temporarily liquefies the interstitial barrier, allowing easy dispersal of local anaesthetic through cleavage of tissue planes. This prospective, blinded, randomised controlled study investigates the utility of adding hyaluronidase to local anaesthetic in the setting of carpal tunnel release. Methods. 70 consecutive carpal tunnel release patients were recruited and randomised into a control group only receiving local anaesthetic and a hyaluronidase group receiving both hyaluronidase and local anaesthetic. Pain scores were rated using the visual analogue scale (VAS) by patients immediately after local anaesthetic injection and again immediately after the carpal tunnel release. Results. Preoperative VAS scores, taken after local anaesthetic injection, were greater than postoperative VAS scores. Postoperative VAS scores were significantly lower in the hyaluronidase group and tourniquet times were significantly shorter in the hyaluronidase group. Conclusion. Hyaluronidase addition to local anaesthetic in carpal tunnel release resulted in significant reductions in operative time and pain immediately after operation.

Pain on administration of non-alkalinised lidocaine for carpal tunnel decompression: A comparison between the Gale and the "advancing wheal" techniques

METHODS

This study compares two methods of administration of non-alkalinised lidocaine for carpal tunnel decompression in volunteers as well as in patients undergoing carpal tunnel release: The Gale subcutaneous injection technique and another subcutaneous injection technique known as the "advancing wheal" technique. The comparison was done in nine male volunteers and in 20 patients. In the volunteer part of the study, both hands were injected and, hence, each volunteer acted as his own control. In the clinical part of the study, the 20 patients were randomised, with 10 patients receiving the Gale technique and the other 10 receiving the wheal technique.

RESULTS

In volunteers, the advancing wheal technique was associated with less pain; but with a longer duration of injection and a higher number of needle pricks when compared with the Gale technique. Eight volunteers preferred the advancing wheal technique because the overall pain experience was less. One volunteer preferred the Gale technique because it took less time to complete the injection procedure. Clinically, the wheal technique also had a significantly lower mean pain score than the Gale technique.

CONCLUSION

It was concluded that the advancing wheal technique is associated with less pain than the Gale technique.

Does adjusting the pH of lidocaine reduce pain during injection?

BACKGROUND

Receiving local anaestethic injection is painful. A double-blinded randomised study with 32 healthy adult volunteers was performed, with the aim of investigating the effect of buffering lidocaine to reduce the pain during injection.

METHODS

Each participant received two subcutaneous injections of 4.5 ml lidocaine 1% on the lower left and right quadrants of the abdomen. One solution was plain lidocaine (pH 6.55) and the other was lidocaine buffered with sodium bicarbonate in a ratio of 9:1 (pH 7.30). After each injection the participant marked the pain experienced during the injection on a visual analogue scale (VAS; 0 = best, 100 = worst), in addition to verbally stating which injection they found was the least painful.

RESULTS

A total of 20 stated that they preferred the buffered solution, while eight said that they preferred the unbuffered solution (p < 0.002). The mean VAS pain-score was 15 (SD = 12) for the buffered injections and 20 (SD = 12) for the unbuffered injections (p < 0.017).

CONCLUSION

The conclusion is that the pain experienced during the injection of lidocaine can be significantly reduced by buffering the solution before injection.

WITHDRAWN: Adjusting the pH of lidocaine for reducing pain on injection

May 2015

This review was originally published in 2010 and at that time complied with Cochrane’s Commercial Sponsorship Policy. The Commercial Sponsorship policy was updated in 2014 (http://community.cochrane.org/organisational‐policy‐manual/appendix‐5‐commercial‐sponsorship‐policy ). This review is no longer compliant with that policy.

The non conflicted members of the original team of authors have decided not to update the review. We have therefore decided to withdraw the review and seek new authors to update it

The editorial group responsible for this previously published document have withdrawn it from publication.

Combating inadequate anesthesia in periapical infections, with sodium bicarbonate: a clinical double blind study

INTRODUCTION

Local anesthetics are generally much less effective when administered in inflamed tissues.

PURPOSE

This study was conducted to validate the addition of sodium bicarbonate in local anesthetics to increase its effectiveness as local infiltrations in teeth associated with periapical infections.

METHODS

Two hundred subjects requiring extraction of maxillary teeth with periapical infections were enrolled. These subjects were divided in two groups of 100 subjects each. One group received local infiltration with 2 % lignocaine and 1:80,000 adrenaline, and the other group received local infiltration with sodium bicarbonate as an adjunct to the above mentioned local anesthetic solution. All extractions were performed using a consistent intra-alveolar technique by a single operator. Both the patient and the operator were blinded to the contents of local anesthetic solution. Data related to the onset of action of local anesthesia, pain experienced by the patient while undergoing extraction on two scales-"the visual analog scale and the verbal response scale", and any requirement of repeated injections during the procedure was recorded.

RESULTS

Clinical and statistical data confirmed that the addition of sodium bicarbonate in local anesthetics did increase the efficacy of local anesthesia in inflamed tissues.

CONCLUSION

It has been observed in this study that the action of sodium bicarbonate in local anesthetics increases the pH levels of these solutions, thus possibly making them more effective in an acidic environment.

Update/Review: changing of use of local anesthesia in the hand

Supplemental Digital Content is available in the text.

Summary:

Among the many advances in local anesthesia of the hand, some of the most significant changes in the last 5 years have been the following: (1) the acceptance of safety of locally infiltrated epinephrine with lidocaine for hemostasis, which has removed the need for sedation, brachial plexus blocks, and general anesthesia for most common hand surgery operations and minor hand trauma. (2) The elimination of the 2 injection finger block technique in favor of the single injection palmar block. (3) Local anesthesia can now be consistently injected in the hand with minimal pain. (4) Liposomal release of local anesthetic after injection into the surgical site can provide pain control up to 3 days. This article reviews the impact and best evidence related to these changes.

How acidic is the lidocaine we are injecting, and how much bicarbonate should we add?

BACKGROUND

The infiltration of local anesthetics can be painful, which is likely due, in part, to their acidity. In spite of a Cochrane study that recommended neutralizing lidocaine with bicarbonate to decrease the pain of injection, not many surgeons have adopted the practice, and there are many 'recipes' for how much bicarbonate one should add.

OBJECTIVE

To determine the acidity of lidocaine and the correct ratio of bicarbonate that should be added to neutralize lidocaine to achieve body pH.

METHODS

Fifty samples each of commonly used anesthetics (lidocaine 1% and 2%, with and without epinephrine 1:100,000) were obtained and tested for pH. Data were also analyzed according to whether the vials had been previously opened. Ten additional samples of lidocaine 1% with 1:100,000 epinephrine were titrated against sodium bicarbonate 8.4% and tested for pH and the presence of precipitate.

RESULTS

A solution of 1% lidocaine with 1:100,000 epinephrine had a mean (± SD) pH of 4.24±0.42, and 2% lidocaine with 1:100,000 epinephrine had a mean pH of 3.93±0.43. Plain 1% lidocaine had a pH of 6.09±0.16, and plain 2% lidocaine had a pH of 6.00±0.27. Epinephrine-containing solutions were more acidic when they had been previously opened. One per cent lidocaine with epinephrine required 8.4% sodium bicarbonate at a ratio of 1.1 mL:10 mL to 1.8 mL:10 mL to achieve the target tissue pH of 7.38 to 7.62.

CONCLUSION

Lidocaine with epinephrine was approximately 1000 times more acidic than subcutaneous tissue. The addition of bicarbonate to the local anesthetic solution is simple to perform and is inexpensive. The proper volume ratio of 8.4% sodium bicarbonate to 1% lidocaine with 1:100,000 epinephrine is approximately 1 mL:10 mL. Surgeons should be more aware of the simplicity and value of buffering with bicarbonate to decrease the pain of injection.

The effect of buffered lidocaine in local anesthesia: a prospective, randomized, double-blind study

PURPOSE

Open carpal tunnel decompression under local anesthesia is routinely done by many surgeons. However, patients complain of pain during the injection of local anesthesia. This prospective, double-blind, randomized study was to compare the pain visual analog scale (VAS) scores of local anesthesia using lidocaine with and without sodium bicarbonate in patients with bilateral carpal tunnel syndrome.

METHODS

Twenty-five patients underwent bilateral simultaneous carpal tunnel decompression. All had topical anesthetic cream applied on the palm and wrist before the lidocaine block. In a randomized manner, half of the hands were blocked with nonbuffered lidocaine and half were blocked with buffered lidocaine. Pain was evaluated on a VAS score.

RESULTS

The mean pain VAS score in the hand with buffered lidocaine was 4.6 ± 1.5 and 6.5 ± 1.5 for the hand with nonbuffered lidocaine. After adjustment for individual threshold of the pain, the mean pain VAS score changed into 4.6 ± 1.3 with buffered lidocaine and 6.6 ± 1.7 without buffered lidocaine.

CONCLUSIONS

In open carpal tunnel surgery, the use of buffered lidocaine for local anesthesia reduces the anesthetic pain effectively.

TYPE OF STUDY/LEVEL OF EVIDENCE

Therapeutic I.

Patient satisfaction with tourniquet application and local anaesthesia infiltration in carpal tunnel decompression and the relationship with overall satisfaction

This was a prospective study designed to determine what effect poor tolerance to tourniquet application and local anaesthesia infiltration in open carpal tunnel decompression has on overall patient satisfaction with the surgical procedure. Fifty patients were recruited into the study. Visual analogue scores (VAS) were recorded postoperatively for pain related to tourniquet application, local anaesthesia infiltration and the surgical procedure overall. In terms of the procedure, poor tolerance to the tourniquet and local anaesthetic showed no significant relationship to the overall patient satisfaction (Student t-test). The factors, which are related to satisfaction with carpal tunnel decompression, are discussed.

Adjusting the pH of lidocaine for reducing pain on injection

BACKGROUND

Lidocaine administration produces pain due to its acidic pH.

OBJECTIVES

The objective of this review was to determine if adjusting the pH of lidocaine had any effect on pain resulting from non-intravascular injections in adults and children. We tested the hypothesis that adjusting the pH of lidocaine solution to a level closer to the physiologic pH reduces this pain.

SEARCH STRATEGY

We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library, to June 2010); Ovid MEDLINE (1966 to June 2010); EMBASE (1988 to June 2010); LILACS (1982 to June 2010); CINAHL (1982 to June 2010); ISI Web of Science (1999 to June 2010); and abstracts of the meetings of the American Society of Anesthesiologists (ASA). We checked the full articles of selected titles. We did not apply any language restrictions.

SELECTION CRITERIA

We included double-blinded, randomized controlled trials that compared pH-adjusted lidocaine with unadjusted lidocaine. We evaluated pain at the injection site, satisfaction and adverse events. We excluded studies in healthy volunteers.

DATA COLLECTION AND ANALYSIS

We separately analysed parallel-group and crossover trials; trials that evaluated lidocaine with or without epinephrine; and trials with pH-adjusted lidocaine solutions < 7.35 and ≥ 7.35. To explain heterogeneity, we separately analysed studies with a low and higher risk of bias due to the level of allocation concealment; studies that employed a low and a higher volume of injection; and studies that used lidocaine for different types of procedures.

MAIN RESULTS

We included 23 studies of which 10 had a parallel design and 13 were crossover studies. Eight of the 23 studies had moderate to high risk of bias due to the level of allocation concealment.Pain associated with the infiltration of buffered lidocaine was less than the pain associated with infiltration of unbuffered lidocaine in both parallel and crossover trials. In the crossover studies, the difference was -1.98 units (95% confidence interval (CI) -2.62 to -1.34) and in the parallel-group studies it was -0.98 units (95% CI -1.49 to -0.47) on a 0 to 10 scale. The magnitude of the pain decrease associated with buffered lidocaine was larger when the solution contained epinephrine. The risk of bias, volume of injection, and type of procedure failed to explain the heterogeneity of the results.Patients preferred buffered lidocaine (odds ratio 3.01, 95% CI 2.19 to 4.15). No adverse events or toxicity were reported.

AUTHORS' CONCLUSIONS

Increasing the pH of lidocaine decreased pain on injection and augmented patient comfort and satisfaction.

Efficacy of bicarbonate in decreasing pain on intradermal injection of local anesthetics: a meta-analysis

OBJECTIVE

Intradermal injection of local anesthetic often results in pain on injection due in part to the acidic pH of commercially prepared solutions, which are optimized to prolong shelf life. Although there are other possible explanations (eg, noxious properties of local anesthetics, pressure effect of infiltration), the etiology is most likely multifactorial. Although addition of bicarbonate to local anesthetics may decrease pain on intradermal injection, the extent of this analgesic effect is uncertain. We performed a meta-analysis of available trials investigating pain during intradermal injection of buffered local anesthetic preparations.

METHODS

We searched the National Library of Medicine's PubMed database for all relevant articles published on the topic through November 2006. Inclusion criteria included double-blind, randomized controlled trials and use of a visual analog scale to measure pain on infiltration of local anesthetic buffered with sodium bicarbonate compared with that of unbuffered local anesthetic. Meta-analysis was performed using the Review Manager 4.2.7 (The Cochrane Collaboration, 2004). A random-effects model was used.

RESULTS

Our search resulted in 86 abstracts, of which 12 articles met all inclusion criteria. Overall, there were 609 observations for buffered local anesthetic and 615 for unbuffered local anesthetic. Use of buffered local anesthetic resulted in a statistically lower weighted mean difference in visual analog scale of -1.17 (95% confidence interval, -1.68 to -0.67) compared with unbuffered local anesthetic.

CONCLUSIONS

Our systematic review suggests that the use of buffered local anesthetics seems to be associated with a statistical decrease in pain of infiltration when compared with unbuffered local anesthetic.

Improved tolerability of open carpal tunnel release under local anaesthetic: a patient satisfaction survey

Carpal tunnel decompression is the most commonly performed procedure in hand surgery. This study was done to assess the effectiveness and acceptability by patients of open carpal tunnel release under local anaesthetic. We compare our results with both the literature and those of our previous study, after which were made alterations to improve the surgical and anaesthetic technique. These alterations included (a) injecting local anaesthetic with a dental syringe and a 27G needle in two stages along the proposed line of the incision and (b) omitting the use of a tourniquet, relying on the local anaesthetic with adrenaline to maintain a bloodless field during the procedure.