Buffered lidocaine 1%/epinephrine 1:100,000 with sodium bicarbonate (sodium hydrogen carbonate) in a 3:1 ratio is less painful than a 9:1 ratio: A double-blind, randomized, placebo-controlled, crossover trial

A Buffered Local Anesthetic Without Epinephrine: Development, Characterization, and In Vivo Efficacy and Toxicity Analysis

Lidocaine hydrochloride (HCl) 2% with 1:100,000 epinephrine (LW/E) is widely used to prevent pain during dental procedures and has been associated with injection sting, jittering effects, slow onset, and a bitter aftertaste. Since LW/E's introduction in 1948, no significant modifications have been proposed. This study aims to design and characterize an improved dental lidocaine HCl injectable formulation without epinephrine (LW/O/E) via buffers, sweeteners, and amino acids. LW/O/E injections were prepared with pH and osmolality values of 6.5-7.0 and 590-610 mOsm/kg. Using the electronic tongue (ETongue), the LW/O/E injectable formulations were characterized for viscosity, injectability, and taste analysis. The results were compared with the LW/E control. In vivo efficacy and anesthetic duration of the samples were measured through radiant heat tail-flick latency (RHTFL) and hot plate (HP) tests and local toxicity was assessed after a single intra-oral injection in Sprague Dawley rats (SDR). The viscosity and injectability values of the LW/O/E samples were found to be comparable to the LW/E injection. ETongue taste analysis showed an improvement in bitterness reduction of the LW/O/E samples compared to the LW/E formulation. Toxicity studies of samples in SDR showed minor and transient signs of erythema/eschar and edema. Anesthetic duration via RHTFL and HP paw withdrawal latency time in SDR were found to be comparable for the LW/O/E Sample 3A and the LW/E injection (p < 0.05). In conclusion, the buffered, higher osmolality and reduced bitterness developed LW/O/E formulation (Sample 3A) could be considered a promising alternative to the LW/E formulation for dental use.

Optimizing pediatric periprocedural pain management part II-Adjunct therapies to support the use of infiltrative anesthetics

Pediatric procedure-related pain management is often incompletely understood, inadequately addressed, and critical in influencing a child's lifelong relationship with the larger healthcare community. We present a comprehensive review of infiltrative anesthetics, including a comparison of their mechanisms of action and relative safety and efficacy data to help guide clinical selection. We also describe the multimodal utilization of adjunct therapies-in series and in parallel-to support the optimization of pediatric periprocedural pain management, enhance the patient experience, and provide alternatives to sedation medication and general anesthesia.

Evaluation of the efficacy of buffered local anesthetic in extraction of infected teeth-randomized double-blind study

PURPOSE

In the presence of infection, acidic pH of a lignocaine local anesthetic causes undesirable effects such as burning on injection, relatively slow onset, and lack of numbness. Buffered lignocaine will increase the pH of the solution and may resolve above problems. Thus, the objective of this study is to compare the efficacy of buffered lignocaine with that of commercial lignocaine.

METHOD

Seventy patients with infected teeth were randomly divided into two equal groups. The study group received buffered lignocaine (8.4% sodium bicarbonate added to 2% lignocaine mixture) while the control received commercial lignocaine preparation (2% lignocaine with 1:80,000 adrenaline). Burning while injection, pain using VAS scale and onset of action with EPT (electric pulp tester) were recorded.

RESULTS

In the study group, the VAS score after injection was 1.20 ± 0.68 and the control group was 2.57 ± 0.92 (p = 0.001). There was a statistically significant reduction in pain reduction in the study group. The time of onset was 3.97 ± 0.71 and 5.67 ± 1.15 min, respectively, and the difference was statically significant. Only one-third of the study group experienced burning on injection as compared to two-thirds in the control group.

CONCLUSION

Buffered lignocaine is more effective as compared to commercial lignocaine in the extraction of infected teeth.

CTRI NUMBER

CTRI/2022/01/039476.

Sustainable dermatology-A practical guide for the Australian dermatologist

Globally, healthcare systems can account for up to 10% of national CO2 emissions. There is increasing awareness of the need to act to reduce the impact on our planet by living sustainably in our personal and professional lives. Literature on sustainability can be complex, and with so many demands on our attention and time, it is challenging for the practising dermatologist to grasp where to begin. This manuscript provides a practical guide with quantifiable impacts for each action. With mindful use of resources, both profitability and the well-being of patients and doctors can align with environmental protection.

Buffered versus Non-buffered Local Anaesthesia in Minor Oral Surgery - A Comparative Study

Introduction

Commercially available local anaesthetics are acidic solutions associated with the vasopressor sting on injection, relatively slower onset of action and pain during palatal injections. The above drawbacks can be addressed by anaesthetic buffering. This prospective study was aimed at comparing the efficacy of buffered and non-buffered local anaesthesia in the extraction of grossly decayed maxillary molar teeth in relation to pain on local infiltration, onset and duration of action of local anaesthesia.

Materials and Methods

This is a prospective randomised controlled trial done on 100 patients who required bilateral extraction of maxillary molar teeth. In the study group, patients were given buffered local anaesthesia (which was prepared by mixing 2% lignocaine with 1:80,000 adrenaline and 8.4% sodium bicarbonate) before extraction. In the control group, non-buffered local anaesthesia (2% lignocaine with 1:80,000 adrenaline) was given before extraction.

Results

Statistical data confirmed that buffering reduces pain on infiltration, decreases the onset and increases the duration of action of the local anaesthesia compared to non-buffered local anaesthesia. All the parameters measured were statistically significant (P = 0.001).

Discussion

The study concludes that buffered local anaesthesia was more beneficial than non-buffered local anaesthesia in reducing pain on injection, providing a quicker onset of local anaesthesia and increasing the duration of action of the local anaesthesia. Buffering is a safe, easy and efficient process and should be routinely followed to provide a better experience to the patients.

Buffered 2% articaine in buccal infiltration of mandibular molars: a randomized triple-blind clinical trial

This crossover study aimed to compare the anesthetic effects of buffered 2% articaine with 1:200,000 epinephrine with that of non-buffered 4% articaine with 1:200,000 epinephrine. Forty-seven volunteers were administered two doses of anesthesia in the buccal region of the second mandibular molars in two sessions using 1.8 mL of different local anesthetic solutions. The onset time and duration of pulp anesthesia, soft tissue pressure pain threshold, and the score of pain on puncture and burning during injection were evaluated. The operator, volunteers, and statistician were blinded. There were no significant differences in the parameters: onset of soft tissue anesthesia (p = 0.80), duration of soft tissue anesthesia (p = 0.10), onset of pulpal anesthesia in the second (p = 0.28) and first molars (p = 0.45), duration of pulp anesthesia of the second (p = 0.60) and first molars (p = 0.30), pain during puncture (p = 0.82) and injection (p = 0.80). No significant adverse events were observed. Buffered 2% articaine with 1:200,000 epinephrine did not differ from non-buffered 4% articaine with 1:200,000 epinephrine considering anesthetic success, safety, onset, duration of anesthesia, and pain on injection.

Buffered Versus Nonbuffered Local Anesthetics and Local Pain Scores in Upper Eyelid Blepharoplasty: Randomized Controlled Trial

PURPOSE

This split-face study aimed to see whether different types of local anesthetics or their buffered/nonbuffered combinations produce lower pain scores in upper eyelid blepharoplasty.

METHODS

The study involved 288 patients, randomly divided into 9 groups: 1) 2% lidocaine with epinephrine-Lid + Epi; 2) 2% lidocaine with epinephrine and 0.5% bupivacaine (1:1)-Lid + Epi + Bupi; 3) 2% lidocaine with 0.5% bupivacaine (1:1)-Lid + Bupi; 4) 0.5% bupivacaine-Bupi; 5) 2% lidocaine-Lid; 6) 4% articaine hydrochloride with epinephrine-Art + Epi; 7) buffered 2% lidocaine/epinephrine with sodium bicarbonate (SB) in a 3:1 ratio-Lid + Epi + SB; 8) buffered 2% lidocaine with SB in a 3:1 ratio-Lid + SB; 9) buffered 4% articaine hydrochloride/epinephrine with SB in a 3:1 ratio-Art + Epi + SB. Following the injection of the first eyelid and a 5-minute period of soft pressure on the injection site, patients were asked to rate their pain level on the Wong-Baker Face Pain Rating Visual Analogue Scale. Rating of the pain level was repeated 15 and 30 minutes following anesthetic administration.

RESULTS

The lowest pain scores at the first time point were observed in Lid + SB when compared with all of the other groups ( p < 0.05). At the final time point, significantly lower scores were also observed in Lid + SB, Lid + Epi + SB, and Art + Epi + SB when compared with the Lid + Epi group ( p < 0.05).

CONCLUSION

These findings could help surgeons select an appropriate combination of local anesthetics, particularly in patients with lower pain threshold and tolerance because buffered combinations of local anesthetics produce significantly lower pain scores compared with nonbuffered solutions.

Pain Management in Dermatology

BACKGROUND

The dermatologist has to deal with many situations where the patient feels pain and must therefore know how to manage it.

SUMMARY

The aim of this review was to explore the treatments available to manage pain in dermatology in different circumstances, with an emphasis on pharmacological and non-pharmacological interventions specifically studied in dermatology.

Effects of lidocaine incorporation (without epinephrine) on pain and 2-week complications of botulinum toxin: a double-blind randomized placebo-controlled clinical trial

No study has assessed the effects of the incorporation of isolated lidocaine into botulinum toxin for reducing its pain or complications. Studies on the dilution of botulinum toxin with other materials are as well extremely few, small, and limited methodologically. Therefore, we aimed to evaluate, for the first time, the effects of the incorporation of lidocaine alone into botulinum toxin type A on post-injection pain and complications. In this 2-week prospective, multicenter, double-blind randomized placebo-controlled clinical trial, 729 participants (667 females) were enrolled. They were randomized into placebo and lidocaine dilutions (about 2:1), and then into two brands of toxins (Dysport versus Xeomin). Hence, there were 4 subgroups. In the 2 experimental subgroups, botulinum toxin was diluted with 2% lidocaine without adrenaline; in the 2 control subgroups, botulinum toxin was diluted with normal saline as a placebo. After injection, the pain level was recorded (as an 11-scale numerical rating scale from 0 to 10). After 2 weeks, post-injection complications were assessed based on the participants' reports and the surgeon's observations. Data were analyzed using 3-way ANCOVA, multiple binary logistic regression, and bivariable analyses (α = 0.05, β ≤ 0.1). The mean ± SD pain levels in the lidocaine group (n = 263) and the placebo group (n = 466) were 3.51 ± 2.04 and 4.15 ± 2.35, respectively. The mean ± SD pain levels in the subgroups 'Xeomin-Lidocaine (n = 61), Dysport-Lidocaine (n = 202), Xeomin-Placebo (n = 133), and Dysport-Placebo (n = 333)' were respectively 3.39 ± 1.86, 3.55 ± 2.09, 4.61 ± 2.49, and 3.97 ± 2.24. Lidocaine incorporation (P = 0.001), Dysport brand (P = 0.030), and younger age (P = 0.032) [but not sex (P = 0.406)] reduced pain. The only significant findings for 2-week complications were for the associations observed between aging with increased asymmetry (P = 0.022, OR = 1.032) and a need for a retouch (P = 0.039, OR = 1.021). Botulinum toxin dilution with lidocaine alone (without adrenaline or other ingredients) can reduce pain without affecting postinjection complications. Toxin brands may cause different extents of pain. Aging, but not sex, may increase pain. Two-week complications were not affected by any factors, except aging in the case of asymmetry and the need for a botulinum toxin retouch.

Local anaesthetics in dermatological surgery: a review of adjuncts and pain reduction techniques

A variety of adjuncts for local anaesthesia (LA) exists for dermatological surgery, along with many options to reduce the pain of LA. This review aims to summarize the evidence relating to such adjuncts and methods to reduce the pain of LA. Adjuncts to LA can be an important consideration to optimize anaesthetic effect. Current evidence suggests that buffering and warming of LA fluid, along with cooling, pinching and administering vibrations to the skin are effective at reducing pain during administration. In this review, no significant difference in pain reduction was found between cooling and administering vibrations to the skin. Studies demonstrate that, overall, LA injection into distal sites is safe. However, the evidence specific to dermatological surgery is limited with regard to ways to reduce pain during LA injection and in determining the safety of LA for distal sites with confidence. Further high-quality research in the form of multicentre randomized controlled trials is required.

Local Anesthesia in Interventional Radiology

Interventional radiology is an evolving field that treats a variety of diseases. Local anesthetics is an important component of pain management during interventional radiologic procedures. It is highly effective and generally safe for routine procedures. However, local anesthetics can be associated with painful initial injection, allergic reactions, and rare but potentially devastating systemic toxicities. Recent evidence has shown that buffered solution and warm local anesthetics may reduce injection discomfort and improve clinical efficacy. Sensible safety practices and prompt recognition/treatment of the systemic toxicity are of paramount importance to provide safe local anesthesia. Interventional radiologists should be familiar with the basic pharmacology, common local anesthetics, optimizing strategies, complications, and management to provide safe and effective local anesthesia for patients.

Dermatological Conditions Inducing Acute and Chronic Pain

Pain is a common condition in dermatology. The aim of this review is to analyse the characteristics of pain in dermatology. Some skin diseases are conventionally known to cause pain; e.g. ulcers, pyoderma gangrenosum and herpes zoster. Common dermatoses, such as psoriasis or atopic dermatitis, can also cause significant pain. Some conditions are characterized by neuropathic pain and/or pruritus, without visible primary lesions: e.g. the neurocutaneous diseases, including small fibre neuropathies. Patients often fear pain in skin surgery; however, surgical procedures are rather well tolerated and any pain is mainly due to administration of local anaesthetic. Some therapies may also be uncomfortable for the patient, such as photodynamic therapy or aesthetic procedures. Thus, pain in dermatology is common, and its aetiology and characteristics are very varied. Knowledge of the different situations that cause pain will enable dermatologists to propose suitable analgesic solutions.

Comparison of the WALANT and the PFNB techniques in the surgical treatment of unimalleolar fractures: a prospective study

The popliteal fossa nerve block (PFNB) technique is one of the most popular anesthesia method in the foot and ankle surgery. The wide awake local anesthesia no tourniquet (WALANT) technique is an local anesthetic method and it has been gaining popularity in orthopedic surgery in recent years. Our aim is to compare the efficacy of the WALANT and the PFNB techniques in pain management. This prospective study included 40 patients with lateral malleolar and medial malleolar fractures. The first group was anesthetized using the WALANT technique; in the second group, PFNB was performed. All patients were evaluated for intrasurgical bleeding amounts, mean arterial pressure, surgery time and VAS scores for presurgical pain, pain during the local anesthetic injection sequence, mean intrasurgical pain, mean postsurgical pain. A total of 40 patients in both groups were successfully operated on with the WALANT and the PFNB techniques. When the two groups were compared, statistically significant differences were observed for mean intrasurgical VAS (p = 0.033), mean postsurgical VAS (p = 0.038) and intrasurgical bleeding (p = 0.006). No significant difference was found in pain scores during anesthetic injection (p = 0.529), mean arterial pressure (p = 0.583) and surgery time (p = 0.277). The PFNB technique is more successful in pain management in the treatment of the unimalleolar fractures. Intrasurgical bleeding amounts were less detected in the WALANT tech- nique. The both techniques are a reliable and suitable anesthetic method in the surgical treatment of uni- malleolar fractures.

Spinal Injections

Spinal pain is a common complaint and cause of disability in the United States, affecting most individuals at some point in their lives. The complex anatomy of the spine leads to multiple potential and coexisting etiologies for pain, and the differentiation of these sources can present a diagnostic challenge. Image-guided spinal injections can provide both diagnostic information identifying pain location as well as prolonged therapeutic relief as an alternative to medical management. Anesthetic and corticosteroid medications can be administered within the epidural space through transforaminal or interlaminar approaches, blocking various sensory nerves, or directly within the facet joints. Proceduralists must be aware of associated patient considerations, techniques, and potential complications to perform the procedures safely. We discuss image-guided spinal injection techniques, based on best practices and our experiences.

Pharmacological and clinical implications of local anaesthetic mixtures: a narrative review

Various techniques have been explored to prolong the duration and improve the efficacy of local anaesthetic nerve blocks. Some of these involve mixing local anaesthetics or adding adjuncts. We did a literature review of studies published between 01 May 2011 and 01 May 2021 that studied specific combinations of local anaesthetics and adjuncts. The rationale behind mixing long- and short-acting local anaesthetics to hasten onset and extend duration is flawed on pharmacokinetic principles. Most local anaesthetic adjuncts are not licensed for use in this manner and the consequences of untested admixtures and adjuncts range from making the solution ineffective to potential harm. Pharmaceutical compatibility needs to be established before administration. The compatibility of drugs from the same class cannot be inferred and each admixture requires individual review. Precipitation on mixing (steroids, non-steroidal anti-inflammatory drugs) and subsequent embolisation can lead to serious adverse events, although these are rare. The additive itself or its preservative can have neurotoxic (adrenaline, midazolam) and/or chondrotoxic properties (non-steroidal anti-inflammatory drugs). The prolongation of block may occur at the expense of motor block quality (ketamine) or block onset (magnesium). Adverse effects for some adjuncts appear to be dose-dependent and recommendations concerning optimal dosing are lacking. An important confounding factor is whether studies used systemic administration of the adjunct as a control to accurately identify an additional benefit of perineural administration. The challenge of how best to prolong block duration while minimising adverse events remains a topic of interest with further research required.