No full-text available
To read the full-text of this research,
you can request a copy directly from the authors.
Comparison of Three Modified Lidocaine Solutions for Use in Eyelid Anesthesia
Abstract
To compare pain on injection and the efficacy of anesthesia of three modified lidocaine solutions for use in eyelid surgery: 1) 2% lidocaine with 1:100,000 epinephrine, 2) 2% lidocaine with 1:100,000 epinephrine buffered 9:1 with 8.4% sodium bicarbonate, and 3) 2% lidocaine with 1:100,000 epinephrine diluted 1:9 with 0.9% bacteriostatic saline solution (with benzyl alcohol).
In this prospective, randomized, double-masked, controlled clinical trial, 30 consecutive patients undergoing bilateral identical eyelid surgery were randomized to one of three treatment groups. Group 1 received buffered solution on one side and stock solution on the other, group 2 received bacteriostatic saline diluted solution on one side and stock solution on the other, and group 3 received buffered solution on one side and bacteriostatic saline diluted solution on the other. Patients used a 5-point scale to rate the perceived pain on injection and the pain felt during the operative procedure.
Comparison of mean injection pain scores showed that buffered solution was significantly less painful than unmodified solution (2.2 versus 3.1, p < 0.05), bacteriostatic saline modified solution was significantly less painful than unmodified solution (0.9 versus 3.3, p < 0.05), bacteriostatic saline modified solution was significantly less painful than buffered solution (1.2 versus 2.3, p < 0.05). Comparison of mean intraoperative pain scores demonstrated no significant difference between the solutions in any of the treatment groups.
For local anesthesia in eyelid surgery, bacteriostatic saline modified solution provides more comfort on injection than either buffered or unmodified lidocaine-epinephrine solution and provides an adequate level of anesthesia that does not differ significantly from either the buffered or unmodified solutions.
... PS has been explored as an alternative local anaesthetic option for a variety of indications. These include pain associated with: venipuncture [13], insertion of intravenous catheters [14][15][16][17], subcutaneous drug administration [18], intravenous drug administration [10], intra-articular injections [19], cervical dilatation for suction and curettage [20], periocular surgery [21][22][23][24] and periocular botulinum toxin A injections [25][26][27][28]. ...
... A wide variety of techniques have been adopted with supporting evidence available for the following: solution modification (buffering, dilution, warming), skin cooling with ice, tactile distraction with vibration, slower rate of injection S.V. Hunt and R. Malhotra [21]. The meta-analysis included one study by Yuen and Dolman [23] incorporating PS for anaesthesia in the periocular region in a double-blinded randomised controlled trial comparing injectionassociated pain, and efficacy of anaesthesia for eyelid surgery [23]. They compared 2% lidocaine with 1:100,000 epinephrine (L2E), buffered 2% lidocaine with 1:100,000 epinephrine (BL2E), and L2E diluted 1:9 with PS. ...
... A wide variety of techniques have been adopted with supporting evidence available for the following: solution modification (buffering, dilution, warming), skin cooling with ice, tactile distraction with vibration, slower rate of injection S.V. Hunt and R. Malhotra [21]. The meta-analysis included one study by Yuen and Dolman [23] incorporating PS for anaesthesia in the periocular region in a double-blinded randomised controlled trial comparing injectionassociated pain, and efficacy of anaesthesia for eyelid surgery [23]. They compared 2% lidocaine with 1:100,000 epinephrine (L2E), buffered 2% lidocaine with 1:100,000 epinephrine (BL2E), and L2E diluted 1:9 with PS. ...
We review evidence regarding the use of 0.9% benzyl alcohol in 0.9% sodium chloride solution for periocular injections (‘preserved saline’) including botulinum toxin A injections and local anaesthesia. A literature search was undertaken using search terms ‘bacteriostatic saline’, ‘benzyl-alcohol saline’, ‘benzyl alcohol sodium chloride’ and ‘preserved saline’. Bibliographies identified further sources. There have been 62 studies published on the subject of preserved-saline since 1928. Significantly lower injection-associated pain levels for periocular/facial botulinum toxin injections reconstituted with preserved-saline rather than preservative-free saline are reported by 5 studies. Significantly lower injection-associated pain with preserved-saline diluted lidocaine and epinephrine solution for eyelid anaesthesia compared with unmodified or buffered lidocaine with epinephrine, and adequate anaesthesia, was reported by one study. Thirty-one studies have explored preserved-saline for anaesthetic and seven for bacteriostatic properties, with very low infection rates after periocular botulinum toxin injections, and reduced rates of infection in indwelling catheters when preserved saline is used to flush. A meta-analysis concluded that lidocaine-containing solutions are more effective at reducing pain from insertion of intravenous catheters. Patient-perceived pain related to periorbital injections of local anaesthesia is reduced when the anaesthetic is diluted with benzyl alcohol-preserved saline compared with other dilution or buffering options. Pain is similarly reduced for periocular botulinum toxin injections reconstituted with preserved saline compared with unpreserved saline. Benzyl-alcohol preserved-saline is inexpensive but costlier than unpreserved-saline, with minimal reported complications, particularly with periocular administration, and offers the opportunity to improve the patient experience.
... 47 To date, the medical literature advocating warming and/or buffering techniques has resided almost exclusively with the medical subspecialties. 13,[15][16][17][18][19][21][22][23][24]37,[31][32][33][34][35][36][38][39][40]43,[48][49][50][51][52][53][54][55][56][57][58][59][60][61][62][63] Despite the fairly extensive literature documenting these techniques and their efficacy, it was not until 1998 that two scholarly pieces advocating buffering and warming techniques first appeared in the primary care medical literature. 14,64 Since that time, an additional review of these techniques has appeared in a primary care nursing journal. ...
Background. The authors conducted a study that considered family physicians'-and dentists' knowledge and application of techniques to reduce the pain associated with anesthetic injections. They also assessed practitioners' discomfort with patients' injection pain and needle anxiety/phobia. Methods. The authors designed a questionnaire about awareness and use of 10 techniques for reducing pain of anesthetic injection and mailed it to 2,000 randomly selected family physicians and general dentists. They analyzed the data to examine differences between disciplines regarding awareness and use of techniques, reasons for not using techniques, number of injections given per week, and predictive value of certain demographic variables on reported use of individual techniques and on practitioner reactions to patients'pain and anxiety. Results. The response rate was 35 percent. The authors used the chi(2) test for differences between disciplines' awareness of and use or normse of techniques, Wilcoxon testing to assess differences between disciplines' median values of number of weekly injections and logistic regression to study demographic variables' predictive values (P =.01). General dentists give more injections than do family physicians. Differences existed between disciplines' awareness and use of eight of 10 techniques. Disciplines reported cost and time issues as reasons for not using some techniques. Number of years in practice and age were associated with use of six techniques. Dentists reported feeling greater personal effects of patients'pain and needle anxiety/phobia than did family physicians. Conclusions. Those not using painlessening techniques inaccurately identified time and cost as problems, suggesting that respondents may be less familiar with these techniques than otherwise reported. Further study is recommended. Clinical Implications. Pain reduction techniques for anesthetic injection cost little to implement, are not time liabilities, and can lessen avoidable pain and reduce the incidence of needle phobia.
... 29 It has been demonstrated that saline-modified anesthetic solution provides more comfort on injection than either buffered or unmodified lidocaine solution. 29,30 The time to onset of anesthesia after IANB was found to be similar for both buffered and unbuffered lidocaine solution in the current study. Similarly, faster onset with buffering could not be demonstrated by Whitcomb et al. 12 and Hobeich et al. 13 for IANB and maxillary infiltrations, respectively. ...
Purpose:
Buffering of anesthetic solutions has been suggested to reduce pain on injection and onset of anesthesia. The purpose of this study was to assess the reduction in pain on injection during inferior alveolar nerve block administration in children.
Methods:
A double blind crossover study was designed where 30 six- to 12-year-old patients received two sessions of inferior alveolar nerve block scheduled one week apart. Two percent lidocaine with 1:200,000 epinephrine was given during one appointment, and a buffered solution was given during the other. Pain on injection was assessed using the sound, eye, and motor (SEM) scale, and the time to onset was assessed after gingival probing. The Heft-Parker visual analogue scale (HP-VAS) was self recorded by the patient after administration of local anesthesia.
Results:
When tested using Mann-Whitney analysis, no significant differences were found between the SEM scores (P=0.71) and HP-VAS scores (P=0.93) for the two solutions used. Student's t test was used to assess the difference in the onset of anesthesia, which was also found to be statistically insignificant (P=0.824).
Conclusion:
Buffered lidocaine did not reduce the pain on injection or time to onset of anesthesia for inferior alveolar nerve block in children.
... Pain is reduced predominantly by the inher- ent anesthetic property of benzyl alco- hol rather than by changes in pH as occurs with bicarbonate buffering. 2 Second, an additional technique that has been shown to be effective is application of a vibrating device in the vicinity of the injection. 3 The precise underlying neurophysiological mecha- nisms remain incompletely under- stood, but can be simplified conceptu- ally as a competing regional signal being simultaneously interpreted by the central nervous system, decreasing the perception of pain. ...
We enjoyed the “Five things” article by Strazar and Lalonde.1 Their tips on minimizing pain during administration of local anesthesia are very useful and easily applied. As ophthalmologists and oculoplastic surgeons operating in the exquisitely sensitive periocular skin, we are particularly interested in minimizing pain during injection — both to maximize patient comfort and to prevent serious complications, up to and including vision loss, which can occur with sudden patient movement and intraocular needle penetration. We would like to add 2 more “things to know” about minimizing injection pain associated with local anesthesia.
First, we have found an alternative additive to the local anesthetic to be more effective than sodium bicarbonate at reducing pain during infiltration. We mix all of our lidocaine for local infiltration 1:1 with 0.9% bacteriostatic saline (containing benzyl alcohol). Pain is reduced predominantly by the inherent anesthetic property of benzyl alcohol rather than by changes in pH as occurs with bicarbonate buffering.2
Second, an additional technique that has been shown to be effective is application of a vibrating device in the vicinity of the injection.3 The precise underlying neurophysiological mechanisms remain incompletely understood, but can be simplified conceptually as a competing regional signal being simultaneously interpreted by the central nervous system, decreasing the perception of pain. These additional tips can be considered when infiltrating anesthesia into sensitive areas of the body.
Also, we would like to caution the readership about perpendicular injections in the eyelid tissue. The skin in this area is very thin (especially in elderly patients), and to avoid unintentional globe penetration we believe the needle should be inserted parallel to the skin.
... [2][3][4][5][6][7] Diluting lidocaine with 0.9% bacteriostatic saline (containing benzyl alcohol) has been shown to reduce injection pain in eyelid surgery. 8 Cooling the skin immediately before treatment reduces the pain of dermatologic laser procedures 9 -11 but may be difficult to perform in the periocular region because of the risk of corneal injury. Similarly, topical anesthetic agents, such as eutectic mixture of local anesthetic cream, applied to the skin 1 hour before injection are commonly used on the limbs of infants and children, but inadvertent ocular application when used on the eyelids has been reported to cause corneal de-epithelialization. 12 Sedative agents, such as midazolam, may be useful in anxious patients, but this requires the input of an anesthetist and it is often difficult to finely control the level of sedation; it is arguably preferable not to have patients sedated during eyelid surgery if patient cooperation is required intraoperatively to assess the height of the eyelids. ...
To investigate whether a vibrating device applied in a circular motion to the forehead reduces the pain of local anesthetic injection in upper eyelid surgery.
Prospective, interventional, cross-over, randomized, controlled clinical trial.
Eighty patients undergoing bilateral upper eyelid surgery under local anesthesia.
A vibrating device was applied in a circular motion to participants' foreheads while local anesthetic was injected into 1 eyelid. During injection of anesthetic on the contralateral lid, the device was applied to the forehead in static fashion with the vibration switched off (placebo). The order of intervention was randomized.
After both injections had been given, participants were asked to specify their pain ratings for each injection on a scale of 0 to 10, with 0 representing no pain and 10 indicating the worst pain imaginable. Participants were also asked to qualitatively compare the 2 sides.
The mean pain scores were 3.3 for the vibration-assisted side and 4.5 for the placebo. This difference was statistically significant (P=0.0003); 73% of participants found the vibrated side to be better than the placebo, with 35% finding it a lot or quite a bit better.
Vibration-assisted anesthesia during upper eyelid surgery has a beneficial effect that is highly statistically significant and is clinically significant in terms of patients' qualitative assessment of pain. Further research is needed to determine whether this constitutes a quantitatively clinically significant improvement in pain management.
The author(s) have no proprietary or commercial interest in any materials discussed in this article.
Background
Although local anesthetics have been extensively studied, limited evidence is available regarding the optimal solution for maximizing patient comfort in minor oculoplastic procedures.
Objectives
To determine the optimal anesthetic solution for local infiltration in minor oculoplastic surgeries to maximize patient comfort.
Methods
This systematic review with network meta-analysis of prospective studies was conducted to understand the efficacy of different local anesthetics in combination to maximize patient comfort. The study was designed according to the Cochrane Handbook for Systematic Reviews of Interventions. The population comprised patients receiving local infiltration anesthesia in minor oculoplastic surgeries. Various anesthetics with adjuvants were compared with respect to injection pain, operative bleeding, and complications. Random-effects model was performed. The primary outcome of injection pain was measured using the visual analog scale (VAS) or a preference question (which intervention was the least painful). Other outcomes were operative bleeding and complications, which were evaluated with a similar preference question.
Results
Eleven randomized controlled trials (RCTs) of 521 patients (917 eyes) were included. The network meta-analysis revealed that “bicarbonate-buffered lidocaine with epinephrine” led to a significant decrease in injection pain (preference question) compared to “prilocaine with felypressin” and “lidocaine with epinephrine,” whereas no significant differences were detected in the analysis of injection pain measured using the VAS.
Conclusions
“Bicarbonate-buffered lidocaine with epinephrine” may be the optimal anesthetic solution for local infiltration in minor oculoplastic surgeries due to reduced injection pain, operative bleeding, and postoperative swelling. However, this should be interpreted cautiously as the confidence in the evidence was very low.
The clinical trial registration number
CRD42021260332 (PROSPERO)
Background:
Perceived pain during local anesthesia injections can be effected by the injection sequence.
Objective:
We sought to compare pain levels during local anesthesia injections during upper lid blepharoplasty (ULB) using 2 surgical sequences.
Materials and methods:
We conducted a prospective, randomized clinical trial. Patients with ULB were randomized to either have local anesthesia injection followed by ULB in the right eyelid and then in the left (Group A) or to have local anesthesia injection to both eyelids followed by ULB on both eyelids (Group B). Pain was assessed using a visual analog scale (VAS) for pain score of 0 to 10.
Results:
Forty patients were included and randomized. The mean VAS score in Group A was 2.60 ± 1.84 and 3.30 ± 1.62 (right and left, respectively, p value = .035). The mean VAS score in Group B was 2.55 ± 1.63 and 2.80 ± 1.67 (right and left eyelids, respectively, p value = .258). No intergroup difference in pain was found.
Conclusion:
Patients having sequential anesthesia during ULB perceived more pain on injection to the second eyelid, whereas patients having local anesthesia followed by ULB perceived the same amount of pain in both eyes. Pain levels in both groups were similar. Local anesthesia injections in both groups were well tolerated.
Purpose:
Various factors help minimize pain during the injection of local anesthetic. The majority of current evidence involves nonspecific injection sites. The objective of this review was to provide a comprehensive summary of all existing evidence for methods used to reduce injection pain specifically in the context of periocular procedures.
Methods:
A literature search of the MEDLINE, EMBASE, and Scopus databases was conducted to identify all relevant experimental and observational studies from 1946 to 2018. Studies were included of patients undergoing periocular surgery under subcutaneous local anesthesia whereby outcomes were reported following a specific intervention intended to help reduce pain. Risk of bias was assessed using recognized tools. A subgroup meta-analysis was performed to indirectly compare pooled intervention-versus-control differences for various pain reduction interventions.
Results:
Following the review of 2089 search results, 23 articles representing 1135 patients were included. The methods assessed in the studies included choice of anesthetic agent, buffering, warming, dilution, needle type, administration of an inhalational anesthetic, application of topical anesthetics, iontophoresis, skin cooling with ice, tactile distraction with vibration, and decreasing the rate of injection.
Conclusions:
Methods demonstrating best efficacy included solution modification (buffering, dilution, warming), skin cooling with ice, vibration, transconjunctival topical anesthetic before injection, and decreased rate of injection. Further study is warranted for modification of equipment factors, topical anesthetics, and strategies to reduce pain because of anesthetic infiltration.
Proparacaine or tetracaine drops can be applied to the ocular surface to help minimize the discomfort of subconjunctival injections. Facial prep solutions, bright lights, and repeated opening of eyes intraoperatively to adjust lid height may cause drying and ocular irritation. Treating both eyes helps increase patient comfort and cooperation. Tetracaine is the most potent topical agent1 and can be used directly on the tarsal plate during procedures such as ptosis repair in which anesthetic use is minimized to avoid levator muscle paralysis. Use of topical anesthetic drops should be limited in all patients to prevent iatrogenic corneal epitheliopathy. The postoperative analgesic regimen should never include topical ocular anesthetic agents.
Lidocaine administration produces pain due to its acidic pH.
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.
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.
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.
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.
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.
Increasing the pH of lidocaine decreased pain on injection and augmented patient comfort and satisfaction.
Context
Botulinum A exotoxin is used for various indications, including the treatment of dynamic forehead lines.Objective
To determine whether injection with botulinum A exotoxin reconstituted with preservative-containing normal saline (isotonic sodium chloride) is less painful than injection with exotoxin that has been reconstituted with preservative-free saline.Design
Two arms: (1) retrospective study; (2) double-blind, randomized controlled trial.Setting
A multiple-physician dermatology practice.Patients
(1) Retrospective study—20 consecutive adult patients presenting for treatment of upper-face dynamic lines; (2) prospective study—15 consecutive adult patients presenting for treatment of upper-face dynamic lines.Intervention
In prospective study only, one side (left or right) of the face was treated with exotoxin reconstituted with preservative-containing saline, and the other side, with exotoxin reconstituted with preservative-free saline.Main Outcome Measures
(1) Retrospective study—discomfort at current treatment (with preservative-containing saline) compared with discomfort with most recent prior treatment (with preservative-free saline); (2) prospective study—discomfort on the side treated with preservative-containing saline compared with discomfort on the side treated with preservative-free saline.Results
(1) Retrospective study—18 (90%) of 20 patients reported that treatment with exotoxin reconstituted with preserved saline was less painful than prior treatment with exotoxin reconstituted with preservative-free saline; (2) prospective study—15 (100%) of 15 patients reported less pain in the side of their face treated with exotoxin reconstituted with preservative-containing saline (P<.001). Pain on the preservative-containing side was 54% less. No difference in treatment efficacy between the sides was observed by investigators or patients.Conclusion
Use of preservative-containing saline to reconstitute botulinum A exotoxin can significantly decrease patient discomfort on injection.
Background:
Circular excision by secondary-intention healing is useful for small skin defects (diameter <10 mm). But the injection pain as the local anesthesia is administered one of the patients' biggest concerns. Buffered lidocaine can effectively relieve the injection pain, but it might increase the potential complications. This study examined the effect of buffered lidocaine on wound healing.
Methods:
Patients undergoing circular excision by secondary-intention healing were divided into 2 groups and were administered buffered or unbuffered lidocaine as the local anesthesia. Comparative parameters included injection pain, postoperative pain, complication rate, scar width, and scar quality at 6 months. Statistical differences between the 2 agents were assessed.
Results:
The patients in the buffered group experienced 0.9 fewer scaled injection pain units than did the patients in the unbuffered group (p = 0.009). Complication rates and scar appearance did not show any statistical difference between the 2 groups.
Conclusion:
Buffered lidocaine is useful to relieve the injection pain during the secondary-intention healing, and it is safe to use if it is applied properly.
Ocular adnexal surgery comprises both lacrimal and eyelid surgery. This fi rst chapter is a
general introducti on of the subjects, outlined in this thesis. The essenti als of the anatomy
and physiology of the lacrimal drainage system are summarized. Primary acquired
nasolacrimal duct obstructi on is defi ned and diff erent treatment opti ons are discussed.
The normal upper eyelid anatomy is briefl y described and diff erent eyelid abnormaliti es
together with their treatment possibiliti es are discussed.
OBJETIVO: Comparar a dor causada pela injeção de solução de lidocaína 2% e epinefrina 1:100.000 com a injeção de solução de lidocaína 2% e epinefrina 1:100.000 tamponada com bicarbonato sódico 8,4% na proporção de 9:1 durante a realização de anestesia local em pacientes a serem submetidos a blefaroplastia superior bilateral. MÉTODOS: Estudo prospectivo duplo-cego, onde 25 pacientes foram submetidos a blefaroplastia superior, sob anestesia local. Cada pálpebra recebia uma das duas soluções anestésicas modificadas definidas por sorteio realizado por um dos pesquisadores que não participava do procedimento cirúrgico. Foram observadas as alterações na frequência cardíaca, pressão arterial sistêmica e saturação de oxigênio, comparadas aos índices de base do próprio paciente, obtidas previamente no início do procedimento. Ao término das aplicações, solicitava-se ao paciente uma nota (de 0 a 4) referente a dor. RESULTADOS: Apenas dois parâmetros (frequência cardíaca e saturação de O2) apresentaram diferença estatisticamente significativa durante a aplicação das duas soluções. CONCLUSÃO: Não houve diferença estatisticamente significativa entre a sensação de dor causada pela injeção de solução de lidocaína 2% e epinefrina 1:100.000 com a aplicação da mesma solução tamponada com bicarbonato sódico 8,4% na proporção de 9:1, em pacientes submetidos a blefaroplastia superior bilateral.
Ray and colleagues1 present data on variation in birth sex ratios among Ontario newborns, showing a significant male-biased sex ratio at birth among multiparous Indian and South Korean mothers. The authors suggest that women from these countries may be using prenatal sex determination and selective termination. However, there are plausible, adaptive reasons for variations in both individual- and population-level sex ratios.
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 methods
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.
Plain Language Summary
Adjusting the pH of lidocaine solution for reducing pain on injection
Lidocaine is frequently used to anaesthetize the skin prior to invasive procedures. Its administration produces pain that is thought to be due to the acidic pH of commercial preparations (pH levels between 3.5 and 7.0 compared with the physiologic pH which is between 7.35 and 7.45). The objective of this review was to determine the effect of increasing the pH of a commercial lidocaine preparation on pain associated with its injection in adults and children. We included 23 studies with 1067 participants in the meta‐analysis. Increasing the pH of lidocaine reduced pain and improved patients' comfort and satisfaction. No adverse events were reported. Therefore, increasing the pH of commercial lidocaine solutions with bicarbonate immediately prior to their use should be considered.
A patient with the rare condition of pachydermoperiostosis with secondary ptosis and floppy eyelid was successfully treated with a combination of levator advancement and an upper eyelid tarsal strip. This is the second report in the literature of combined floppy eyelid and ptosis with this condition and the first report of this surgical approach for its management. The histopathology of the excised eyelid tissue found changes consistent with both pachydermoperiostosis and floppy eyelid syndrome.
To determine whether there is a difference in the incidence of short-term complications using plain lidocaine with epinephrine versus the buffered equivalent in eyelid surgery.
The authors performed a prospective, double-masked, randomized study in patients scheduled for combined upper eyelid blepharoplasty and levator advancement ptosis repair surgery with local anesthesia. Exclusion criteria included: documented allergies to lidocaine and/or epinephrine; known pregnancy; profound cognitive impairment; inability to understand the visual analog scale or the informed consent; and previous eyelid surgery. Each subject was his/her own control by using the unbuffered local anesthetic in one eye, while the buffered solution was used in the other eye. The surgeon completed a specific standardized data collection form for quantifying both intraoperative and postoperative complications, such as bleeding, bruising, and edema. Data regarding pain on injection and postoperative pain were collected from patients using a visual analog pain scale.
Thirty-nine patients were included in this study, of which 18 experienced less pain during the injection on the side where buffered lidocaine was used, 11 reported no difference, and 10 reported less pain in the eye injected with unbuffered lidocaine. Injection pain revealed a mean operative pain rating of 4.01 +/- 2.45 in the eye with buffered lidocaine versus 4.49 +/- 2.58 in the control (p = 0.06). There were no significant differences between the buffered and unbuffered lidocaine eyes as regards postoperative bleeding, swelling, or pain, and there was a trend toward less pain on injection with the buffered solution.
There were no significant differences in postoperative pain, swelling, or bleeding with the use of plain versus buffered lidocaine in eyelid surgery. There was a trend for the buffered anesthetic to cause less pain on injection.
To evaluate the long-term results at the donor site in children who underwent harvesting of autogenous fascia lata for frontalis suspension in ptosis correction.
The study design consists of a retrospective, nonrandomized case series. Medical records of 30 patients were reviewed. Each patient was reexamined, evaluating bulging at the donor site. Muscle prolapse was graded as not visible and not palpable, not visible but palpable, mildly visible, or obviously visible. Measurement of the width and length of the leg scar was recorded. Discomfort at the donor site was graded as no discomfort, occasional discomfort, or frequent discomfort.
The mean age of the patients was 7 years (range, 1-15), with a mean follow-up period of 27 months (range, 3-63 months). Fifteen patients (50%) had invisible and impalpable bulging, 2 patients (6.7%) had invisible but palpable bulging, 5 patients (16.7%) had mildly visible bulging, and 8 patients (26.7%) had obviously visible bulging. The mean width of the scar was 7.5 mm, and the mean length was 3.6 cm. Twenty-seven patients (90%) had no functional discomfort of the leg, 2 patients (6.7%) had occasional discomfort, and 1 patient (3.3%) had frequent discomfort that occurred during exercise.
After fascia lata harvesting, most patients had no cosmetic complaints or functional complications. The technique of harvesting fascia lata using a Crawford stripper seems to be safe and satisfactory.
To report the efficacy of the Wies procedure (transverse blepharotomy and marginal rotation) in the management of trichiasis or cicatricial entropion of the upper or lower eyelid.
A retrospective chart review was performed of all cases of Wies eyelid rotations supervised or performed by one surgeon for cicatricial entropion or trichiasis of the upper or lower eyelids over a 16-year period to assess the indications, success rate and complications of the procedure. Where follow-up was less than 6 months, telephone interviews were conducted to assess patient satisfaction with the surgery. Patients not meeting these criteria were excluded from the final analysis. Success was defined as no recurrence of the entropion or trichiasis and/or patient satisfaction at least 6 months postoperatively. Statistical analysis was performed using a chi(2) test.
126 eyelids (77 upper lids, 49 lower lids) were identified in 89 patients (53 single eyelid, 33 multiple eyelids) who underwent a Wies procedure with a minimum follow-up period of 6 months. The mean follow-up period was 67 months (range 6-188 months). The overall success rate was 85%. 13 eyelids (10%) developed complications. 18 eyelids (14%) developed recurrences that required a second procedure. 10 of these second procedures were repeat Wies procedures, one of which was followed by electrolysis. All of these second Wies procedures were successful.
The Wies procedure (transverse blepharotomy and marginal rotation) is reasonably successful in managing trichiasis and cicatricial entropion of either upper or lower eyelids.
To compare pain on injection of two modified anesthetic lidocaine solutions for use in upper blepharoplasty: 2% lidocaine with 1:100,000 epinephrine, and 2% lidocaine with 1:100,000 epinephrine buffered 9:1 with 8.4% sodium bicarbonate.
In this prospective, double-masked study, 25 consecutive patients undergoing upper blepharoplasty were submitted to the anesthesic procedure. Each eyelid received one of two modified lidocaine solutions. Heart rate, systemic arterial pressure and oxygen saturation level were obtained before, during and after injection of two different anesthetic solutions. Patients used a 4-point scale to rate the perceived pain on injection.
All parameters were statistically analyzed and there was a significant difference in heart rate and oxygen saturation level.
Pain on injection of eyelid anesthesia does not differ significantly with either buffered or unmodified lidocaine solutions.
To assess the effectiveness of bicanalicular silicone intubation (SI) in acquired partial nasolacrimal duct (NLD) obstruction.
Retrospective nonrandomized case series
72 tear ducts from 53 patients with severe epiphora due to acquired partial NLD obstruction underwent bicanalicular SI. Mean age at intubation was 55.9 years. The silicone tubes were removed after, on average, 10.4 weeks. Mean follow up period was 29.3 months (range 6 to 66 months). The results were assessed using the Munk score: 0-1: complete success, 2: partial success and 3-4: failure.
Complete success was reported in 47% (31/66). Partial success was reported in 3% (2/66), and no improvement in 50% (33/66). 12% (8/66) was subsequently treated with dacryocystorhinostomy (DCR).
In patients with acquired partial NLD obstruction, we noted a low success-rate for bicanalicular SI. Although it may be considered in patients who refuse DCR surgery, the relatively poor outcome compared to DCR does not justify its systematic use for this indication.
Botulinum A exotoxin is used for various indications, including the treatment of dynamic forehead lines.
To determine whether injection with botulinum A exotoxin reconstituted with preservative-containing normal saline (isotonic sodium chloride) is less painful than injection with exotoxin that has been reconstituted with preservative-free saline.
Two arms: (1) retrospective study; (2) double-blind, randomized controlled trial.
A multiple-physician dermatology practice.
(1) Retrospective study-20 consecutive adult patients presenting for treatment of upper-face dynamic lines; (2) prospective study-15 consecutive adult patients presenting for treatment of upper-face dynamic lines.
In prospective study only, one side (left or right) of the face was treated with exotoxin reconstituted with preservative-containing saline, and the other side, with exotoxin reconstituted with preservative-free saline.
(1) Retrospective study-discomfort at current treatment (with preservative-containing saline) compared with discomfort with most recent prior treatment (with preservative-free saline); (2) prospective study-discomfort on the side treated with preservative-containing saline compared with discomfort on the side treated with preservative-free saline.
(1) Retrospective study-18 (90%) of 20 patients reported that treatment with exotoxin reconstituted with preserved saline was less painful than prior treatment with exotoxin reconstituted with preservative-free saline; (2) prospective study-15 (100%) of 15 patients reported less pain in the side of their face treated with exotoxin reconstituted with preservative-containing saline (P<.001). Pain on the preservative-containing side was 54% less. No difference in treatment efficacy between the sides was observed by investigators or patients.
Use of preservative-containing saline to reconstitute botulinum A exotoxin can significantly decrease patient discomfort on injection.
Pain from local anaesthetic injection for minor eyelid surgery can often be severe enough to be the most unpleasant part of the procedure. This study was aimed at assessing the efficacy of 50 : 50 N(2)O/O( 2) (Entonox) in relieving such pain.
In this randomised placebo-controlled double blind trial, 100 patients were randomised to receive either Entonox or air. Questions regarding pain during the administration of local anaesthetic, discomfort during the procedure and side effects experienced were asked by an investigator who was blinded to the type of gas inhaled.
The difference in pain score between the Entonox and control groups was not statistically significant (p = 0.474). The difference in discomfort score between the two groups was also not statistically significant (p = 0.948). More side effects were noted with Entonox than with air (p = 0.003, statistically significant). However, this was not clinically significant.
Entonox has been used effectively in different specialties for pain relief. However, our study was unable to show this beneficial effect in relieving pain from local anaesthetic injections for minor eyelid surgery.
To demonstrate that injection of botulinum toxin type A is less painful when mixed with preserved saline compared with the suggested preservative-free saline reconstitution.
Two different injections were compared on 20 patients who had prior botulinum toxin type A treatments. Each side was injected with toxin reconstituted with either preserved or nonpreserved (0.9%) saline. The investigators and patients were blinded, and outcome was assessed with a verbal scale. Clinical outcome was subjectively and informally assessed by patient questioning and physician observation.
Injection of botulinum toxin type A was noted to be less painful with the use of the preserved compared with the nonpreserved preparation (P<0.0001). The preserved reconstitution appeared to have no effect on clinical outcome.
Injection of botulinum toxin reconstituted with preserved saline is less painful than nonpreserved saline preparations.
The authors conducted a study that considered family physicians' and dentists' knowledge and application of techniques to reduce the pain associated with anesthetic injections. They also assessed practitioners' discomfort with patients' injection pain and needle anxiety/phobia.
The authors designed a questionnaire about awareness and use of 10 techniques for reducing pain of anesthetic injection and mailed it to 2,000 randomly selected family physicians and general dentists. They analyzed the data to examine differences between disciplines regarding awareness and use of techniques, reasons for not using techniques, number of injections given per week, and predictive value of certain demographic variables on reported use of individual techniques and on practitioner reactions to patients' pain and anxiety.
The response rate was 35 percent. The authors used the chi2 test for differences between disciplines' awareness of and use or nonuse of techniques, Wilcoxon testing to assess differences between disciplines' median values of number of weekly injections and logistic regression to study demographic variables' predictive values (P = .01). General dentists give more injections than do family physicians. Differences existed between disciplines' awareness and use of eight of 10 techniques. Disciplines reported cost and time issues as reasons for not using some techniques. Number of years in practice and age were associated with use of six techniques. Dentists reported feeling greater personal effects of patients' pain and needle anxiety/phobia than did family physicians.
Those not using pain-lessening techniques inaccurately identified time and cost as problems, suggesting that respondents may be less familiar with these techniques than otherwise reported. Further study is recommended.
Pain reduction techniques for anesthetic injection cost little to implement, are not time liabilities, and can lessen avoidable pain and reduce the incidence of needle phobia.
Pain is a side effect of botulinum toxin type-A (BTX-A) injections. The efficiency of the preservative-containing saline solution used as the "dilution solution" for controlling the pain felt during multiple injections in different areas has been investigated by a prospective, randomized, single-blinded, controlled study. A total of 93 patients were divided into three groups for the study. All the patients were given BTX-A. Of these 93 patients, 60 received injections in the upper face, 15 in the neck, and 18 in the axillary regions. The visual analog scale (VAS), a single-dimension pain intensity rating scale, was used to evaluate pain perception. The average VAS values for pain sensation experienced by the groups were 1.2 of 10 points for the upper face area in the experimental group (n = 60) and 4.5 point for the control group. In the neck region (n = 15), the respective scores were 0.6 in the experimental group and 3.9 in the control group. Finally, in the axillary region (n = 18), the respective values were 0.9 and 5.1. The authors conclude that the preservative-containing saline solution significantly decreased pain perception during BTX-A injections (p = 0.000).
A double-masked, randomized clinical trial was conducted to determine if subcutaneous eyelid injections of a bicarbonate-buffered lidocaine-epinephrine-hyaluronidase mixture were less painful than unbuffered injections. Twenty-one patients received both buffered (pH = 7.4) and unbuffered (pH = 4.6) injections. After each injection, patients recorded pain on a scale of 0, "no pain," to 10, "severe pain." Mean pain score for buffered injections was 2.0 versus 4.1 for unbuffered injections (P = 0.0003). Seventeen (81%) of 21 patients ranked the buffered injection less painful. Use of a bicarbonate-buffered lidocaine-epinephrine-hyaluronidase mixture is effective in making ophthalmic anesthesia less painful.
The effects on anaesthesia of adding hyaluronidase to subcutaneous lignocaine were evaluated in a volunteer's forearm.(i) Onset of anaesthetic was immediate.(ii) Loss of surface contour was minimal due to rapid spread of infiltrate.(iii) The area of anaesthesia was more than doubled compared to the control without hyaluronidase. The indications for the use of hyaluronidase in plastic surgery and its effectiveness as an adjunct to nerve blocks are discussed. © 1986 The Trustees of British Association of Plastic Surgeons.
Benzyl alcohol is reported to be painless on injection and to provide limited dermal anesthesia. Benzyl alcohol has also been recommended as an adjuvant to lidocaine to reduce lidocaine's injection pain. There is insufficient data on pain of injection and duration of anesthesia for lidocaine containing benzyl alcohol.
We conducted a randomized, placebo-controlled, double-blinded comparison of intradermal 1% lidocaine with 0.86% benzyl alcohol and plain 1% lidocaine for pain of injection and duration of anesthesia.
Twenty subjects received the above two agents plus normal saline with and without 0.9% benzyl alcohol, with all solutions adjusted to 375 +/- 13 mosm/L.
Lidocaine containing benzyl alcohol was 27% less painful upon injection and provided anesthesia 29% longer than plain lidocaine.
Benzyl alcohol is itself an effective anesthetic and can reduce the pain of injection for lidocaine without adversely affecting its anesthetic properties.
Forty volunteers were asked to compare pain from injection of buffered versus unbuffered local anesthetics given for upper lid and lower lid blepharoplasty. The concentration of the solution was 1 part 8.4% sodium bicarbonate to 5 parts local anesthetic. The surgeons performing the operations were asked to identify any difference in onset of action, hemostasis, or duration of action. Thirty-five of the 40 patients found the buffered anesthetic to be less painful and better tolerated. No difference in hemostasis or duration of action was noted between the buffered or unbuffered solutions, but the buffered solution produced faster onset of action.
Infiltration of commonly used local anesthetics is painful. It has been speculated that the pain on infiltration is a direct consequence of the acidity of the anesthetic solution.
To compare the degree of pain of intradermal infiltration and the duration of anesthesia for 1% lidocaine with epinephrine 1:100,000, 1% lidocaine with epinephrine 1:100,000 with 80 meq/L sodium bicarbonate, bacteriostatic saline solution with 1% lidocaine with epinephrine 1:300,000, and bacteriostatic saline solution with 1% lidocaine with epinephrine 1:100,000.
The study was performed in three phases: 1) double-blind comparison study, 2 and 3) open clinical trials.
Bacteriostatic saline solution with epinephrine 1:300,000 is significantly less painful on intradermal infiltration than lidocaine with epinephrine 1:100,000 with sodium bicarbonate 80 meq/mL. The saline preparation is an effective anesthetic alternative for superficial surgical procedures such as shave and scissors excision, light curettage and electrodesiccation, and superficial CO2 laser vaporization.
The pH values of bacteriostatic saline solution with epinephrine 1:300,000 and lidocaine with epinephrine diluted with bacteriostatic saline solution are 5.3 and 4.2, respectively. Both were found to be less painful than 1% lidocaine with epinephrine with sodium bicarbonate 84 meq/mL, which had a pH of 7.4. It is unlikely that the pain of infiltration is a simple function of the pH of the anesthetic solution.