Article

Pain-temperature relation in the application of local anesthesia

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Abstract

One hundred and thirty-six patients attending for local anaesthetic procedures in the trigeminal area were assigned to four groups. Each group was injected with the anaesthetic solution at temperatures 10 degrees C, 18 degrees C, 37 degrees C and 42 degrees C, respectively. Measurement of pain during injection was made on a numeric scale. The results show a strong relationship between the temperature of the anaesthetic solution and the pain of the injection (p < 0.001). This demonstrates that warming the anaesthetic solution significantly reduces the pain felt by the patient during injection, especially at 42 degrees C.

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... One way of reducing the perception of pain during injection is to warm local anesthetic solutions. Ex-periments of pain perception during the injection of anesthetic solutions at 10°C, 18°C, 37°C and 42°C in the trigeminal area have shown a linear relationship between increased temperature of the anesthetic solutions and a reduction in the perception of pain during injection 6 . Also, previous reports have shown effectiveness of warming anesthetic solutions in areas of the head and the perception of lower intensity of pain during injection using 2% procaine and 1:80.000 ...
... Also, previous reports have shown effectiveness of warming anesthetic solutions in areas of the head and the perception of lower intensity of pain during injection using 2% procaine and 1:80.000 epinephrine at 42°C in plastic surgery 6 , 2% lidocaine and 1:200.000 epinephrine at 37°C in cataract surgery 7 , and 1% lidocaine and 1:100.000 ...
... The aim of this research is to determine the effectiveness of the use of anesthesia at 42°C (107.6°F) in reducing the perception of pain during dental anesthetic injection, compared to use of anesthesia at room temperature (21°C; 69.8°F) in maxillary dental infiltration technique, taking into account the positive results reported by Alonso et al. 6 using anesthesia at 42°C. ...
Article
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Aim: To determine the effectiveness of anesthesia warming control pain feeling during the administration of anesthesia in maxillary infiltration technique nerve block. Methods: A double-blind clinical trial study was designed. Fifty-six volunteers students (mean age 23.1±2.71 years) of Universidad Austral de Chile Dental School (Valdivia, Chile) were participated. They were given 0.9 ml of 2% lidocaine with 1: 100,000 epinephrine (Alphacaine®; Nova DFL - Brazil) by two punctions at buccal vestibule of lateral incisor. In a hemi-arch a warm anesthesia of 42ºC (107.6°F) was administered; and after one week in to contralateral side a room temperature (21ºC; 69.8°F) was administered. In both times with a standard speed. The level of intensity pain perceived during injection was registered and compared by visual analog scale (VAS) of 100mm (Wilcoxon test p
... All but 1 study included in this review was in adolescents and adults. 5,[34][35][36][37][38][39][40][41][42][43][44][45][46][47][48][49] The single children's study was for dental anesthesia. 50 Eight studies included only healthy volunteers. ...
... 37 Two studies injected local anesthetics in other areas of the face. 34,35 Sixteen studies used lidocaine, 5,35-45,47-50 1 study used bupivacaine, 41 and 1 study used procaine. 34 Ten studies used plain local anesthetics, 5,34,35,37,38,40,43,46,47,50 4 studies used buffered local anesthetics, 36,42,45,49 and 4 studies used both (represented in the forest plot graphs and accompanying tables as study A for nonbuffered, and study B for buffered). ...
... 34,35 Sixteen studies used lidocaine, 5,35-45,47-50 1 study used bupivacaine, 41 and 1 study used procaine. 34 Ten studies used plain local anesthetics, 5,34,35,37,38,40,43,46,47,50 4 studies used buffered local anesthetics, 36,42,45,49 and 4 studies used both (represented in the forest plot graphs and accompanying tables as study A for nonbuffered, and study B for buffered). 39,41,44,48 Epinephrine was added to the local anesthetic in 6 studies. ...
Article
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Local anesthetics are the main class of analgesics used for pain management during laceration repair and other minor surgeries; however, they are administered by injection, which is painful. Warming local anesthetics has been proposed as a cost-free intervention that reduces injection pain. A systematic review of the effectiveness of this technique has not yet been undertaken. We determine the effectiveness of warming local anesthetics to reduce pain in adults and children undergoing local anesthetic infiltration into intradermal or subcutaneous tissue. We used published articles from MEDLINE (1950 to June 2010), EMBASE (1980 to June 2010), CINAHL (1982 to June 2010), the Cochrane Library (second quarter 2010), International Pharmaceutical Abstracts (1970 to June 2010), and ProQuest Dissertations and Theses database (1938 to June 2010). We included studies with randomized or pseudorandomized designs and healthy subjects or patients receiving subcutaneous or intradermal injection of local anesthetics that were warmed (body temperature) or not (room temperature). Studies of regional anesthesia and intraarticular, spinal, or periorbital administration of local anesthetics were excluded. Data were extracted onto predesigned forms and verified by 2 reviewers. Quality was assessed with the Cochrane risk of bias tool. The primary outcome was self-reported pain as assessed by a visual analog or numeric rating scale. Data were combined with mean differences with 95% confidence intervals (CIs) by using a random-effects model. Twenty-nine studies were retrieved for close examination and 19 studies met inclusion criteria. A total of 18 studies with 831 patients could be included in a meta-analysis. Seventeen studies had an unclear risk of bias and 1 had a high risk of bias. A mean difference of -11 mm (95% CI -14 to -7 mm) on a 100-mm scale was found in favor of warming local anesthetics. Subgroup analysis of 8 studies investigating the effect of warming on buffered local anesthetics yielded similar results: -7 mm (95% CI -12 to -3 mm). Warming local anesthetics leads to less pain during injection and therefore should be done before administration.
... One method proven to reduce the perception of pain is to warm local anesthetics. [6][7][8] Reports in dentistry are inconsistent. Rogers et al 9 showed that the warmed anesthetic injection was significantly more comfortable than one at room temperature. ...
... A baby bottle warmer was used (Phillips Avent ® , Amsterdam, the Netherlands) similar to that used in previous reports. 6,11,12 The cartridge of anesthetic was left in a hermetically sealed plastic bag that was placed in the warmer containing 300 mL of cold water (21°C). Using the maximum power of the apparatus, the anesthetic fluid reached 42°C (107.6°F) in 3 min 50 seconds. ...
Article
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Background The purpose of this study is to determine the effectiveness of warming anesthesia on the control of the pain produced during the administration of dental anesthesia injection and to analyze the role of Transient Receptor Potential Vanilloid-1 nociceptor channels in this effect. Patients and methods A double-blind, split-mouth randomized clinical trial was designed. Seventy-two volunteer students (22.1±2.45 years old; 51 men) from the School of Dentistry at the Universidad Austral de Chile (Valdivia, Chile) participated. They were each administered 0.9 mL of lidocaine HCl 2% with epinephrine 1:100,000 (Alphacaine®) using two injections in the buccal vestibule at the level of the upper lateral incisor teeth. Anesthesia was administered in a hemiarch at 42°C (107.6°F) and after 1 week, anesthesia was administered by randomized sequence on the contralateral side at room temperature (21°C–69.8°F) at a standardized speed. The intensity of pain perceived during the injection was compared using a 100 mm visual analog scale (VAS; Wilcoxon test p<0.05). Results The use of anesthesia at room temperature produced an average VAS for pain of 35.3±16.71 mm and anesthesia at 42°C produced VAS for pain of 15±14.67 mm (p<0.001). Conclusion The use of anesthesia at 42°C significantly reduced the pain during the injection of anesthesia compared to its use at room temperature during maxillary injections. The physiological mechanism of the temperature on pain reduction could be due to a synergic action on the permeabilization of the Transient Receptor Potential Vanilloid-1 channels, allowing the passage of anesthetic inside the nociceptors.
... More than 30 years ago, a British dentist, Dr. R. Boggia, first described the technique of warming anesthetic preparations as a means of decreasing the 12 The warming of lidocaine to 37 C, or slightly beyond, as a means of effectively reducing injection pain has been replicated in numerous well-controlled studies. [12][13][14][15][16][17][18][19][20][21][22][23] Warming has not been found to affect the anesthetic action or duration of effect adversely. 15 Apart from warming techniques, buffering techniques also have been shown to be highly effective in reducing the pain of anesthetic injection. ...
... 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. ...
Conference Paper
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.
... Only two studies were found, again not discussed by Sultan and Curran (2007), which included larger sample sizes (Allen et al., 2008;Alonso et al., 1993). Unfortunately, their results only cause more uncertainly as Allen et al. (2008) found no benefit in warming (n=140) whereas Alonso et al. (1993) found significant reduction in pain with warm local anaesthetic use (n=136). ...
... Only two studies were found, again not discussed by Sultan and Curran (2007), which included larger sample sizes (Allen et al., 2008;Alonso et al., 1993). Unfortunately, their results only cause more uncertainly as Allen et al. (2008) found no benefit in warming (n=140) whereas Alonso et al. (1993) found significant reduction in pain with warm local anaesthetic use (n=136). ...
Article
Ring block is the most common technique used to anaesthetise digits prior to nail surgery (Serour et al., 2002). However, this can be a painful experience for the patient and potentially affect the success of the surgery (Connolly et al., 1994; Hayward et al., 2006; Yang et al., 2006). Local anaesthetics work by creating a reversible block to both the generation and conduction of a nerve impulse (Malamed, 2004; Saunders and Longworth, 2006). In order to achieve a digital block, the plantar digital nerves must be flooded with local anaesthetic via two separate injections originating from the dorsal surface either side of the toe (Lorimer et al., 2006). Prior to anaesthesia being achieved, the individual can experience discomfort or pain from both the penetration of the needle through the skin and the infiltration of the agent as it is deposited (Kuscu et al. 2008). The pain experienced by patients from these two separate aspects of the injection can be significant and may not always correlate directly with the level of actual tissue damage (Boon et al., 2006; Kumar and Clark, 2005). In attempting to address the pain caused by the needle penetrating the skin, Browne et al. (2000) found that the use of EMLA ® (AstraZeneca, Sweden), a topical local anaesthetic, was effective prior to digital ring block. However, a more recent randomised control trial by Serour et al. (2002) found its use to be ineffective on the toe and was critical of the methodology used in the study by Browne et al. (2000). Either way, application of EMLA ® is expensive and impractical for nail surgery due to its 60 minute application time (Liu et al., 2003; Serour et al., 2002).
... Before and immediately after the injection the subjective response to pain of injection was assessed by asking the patient to choose an integer between 0 and 10 on an ordinal analogue scale, where 0 represented no pain and 10 the worst pain imaginable. Linear visual analogue scales, where a mark is made on a continuous line, are a commonly used method of scoring pain (10)(11)(12)(13)(14)(15). Like Bell et al (15), however, we felt that many of the elderly patients lying supine would have difficulties accurately placing a mark at the desired location on such a scale. ...
... Warming local anesthetic fluids resulted in lower injection pain in parabulbar anesthesia (15, 28) but a similar approach in RBA failed to give any significant differences (29). Investigations on human tissue distant from the eye gave conflicting results (13,14,(30)(31)(32)(33). ...
Article
To assess how the speed of injection of local anesthetic solutions affected pain of injection, bulbar akinesia and analgesia with retrobulbar anesthesia (RBA). 70 patients undergoing RBA for cataract surgery were enrolled in a prospective masked trial. They were allocated randomly to receive 5 ml anesthetic solution injected either within 20 seconds (group A) or within 60 seconds (group B). Additionally, akinesia of the orbicularis muscle was created according to O'Brien's technique. The pain of injection was registered on an ordinal analogue scale immediately before and after RBA. The following data were collected before and 20 minutes after retrobulbar injection: eye motility (Kestenbaum test), and corneal sensitivity (0: no sensitivity; 1: sensitivity remaining). Data were also collected on age, sex, and bulbar length, and any side effects of the intervention. Injection pain did not differ in the two groups. After RBA horizontal and vertical eye motility was slightly lower in group A than group B. Persistent motility was found in 18 patients in group A and 16 in group B. Median horizontal and vertical motility was 0 mm in both groups. Four patients in group A and five in group B had corneal sensitivity persisting after RBA. This comparison of different injection velocities brought to light no significant differences regarding bulbar analgesia and akinesia after RBA.
... Various literatures have reported that warming local anaesthetic solutions to temperatures close to core body temperature reduced the pain associated with their intradermal or subcutaneous injection. [7][8][9][10][11][12][13][14] Authors have postulated that warming lignocaine possibly increases the speed of its action by causing a temperature-dependent shift in its pKa. 15 This alteration in the reaction equilibrium of the lignocaine hydrochloride solution makes more of the active form available to inhibit nerve impulse conduction before any noxious stimulus associated with delivery can be registered by nociceptors. ...
Article
Full-text available
Introduction: Intraurethral instillation of 2% lignocaine hydrochloride is associated with discomfort and stinging sensation, especially to male patients. This study was aimed to determine whether slow instillation and cooled gel reduce this discomfort. Materials and Methods: A prospective randomized study was done comparing initial and procedural discomfort between 2% lignocaine instilled at room temperature and cooled to 4° C, and that instilled over 2 seconds and 10 seconds. Hundred and sixty male patients were divided into two groups of eighty each for the two studies. Results: Significant reduction in initial discomfort was observed with 10ml of 2% lignocaine hydrochloride cooled to 4° C and also when instilled over 10 seconds. Although procedural discomfort was also lesser in these two sets, it was not statistically significant. Conclusions: Discomfort, the most common complaint of male patients during rigid cystoscopy, can be reduced by slow instillation of lignocaine hydrochloride gel and also if the gel is cooled to 4° C.
... Alonso et al 31 reported an inverse relationship between temperature and pain and reported that the highest mean pain level occurred at 10°C followed by 18 o C, 37°C and 42 o C. ...
Article
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Background: Maintaining primary teeth in the oral cavity is of prime importance, and grossly carious teeth may require pulp therapy for the same. Pain on injection and incomplete anesthesia causes failure of the procedure and result in fear and anxiety. Various methods have evolved to overcome this; such as distraction, topical anesthesia, etc. A few techniques regaining popularity in dentistry in recent times is the warming or buffering of the solution prior to administration. This study thus aimed to compare and evaluate the anesthetic efficacy and the patient’s pain reaction to pre-warmed, buffered and conventional 2% lignocaine for the success of Inferior Alveolar Nerve Block in mandibular primary molars undergoing pulp therapy. Methods: The study is a randomized, split-mouth trial. Sixty children between six -12 years, requiring pulp therapy bilaterally on mandibular primary molars, were administered conventional, buffered or pre-warmed 2% lignocaine on two separate appointments. Various parameters were assessed using objective and subjective scales. Results: Pre-warmed and buffered anesthetics had lesser pain on injection (p<0.001, p<0.001) and pulp therapy (p=0.001, p=0.014), faster onset of action (p=0.004, p=0.001), lower SEM Sound (p=0.035, p=0.028), Eye (p< 0.001, p=0.013) and Motor (p=0.008, p=0.021) scores and shorter duration of action (p< 0.001, p=0.015). No significant difference was found between the two modified solutions. Thus pre-warmed and buffered anesthetic solutions fared better than the conventional solution for all parameters but had no advantage over each other. Conclusion: Buffering or pre-warming the anesthetic solution reduces pain on administration and during procedures in children. Trial registration number: CTRI/2017/02/007922
... [10] Various authors havefound that anesthetic formulations with higher pH values had faster onset. [10][11][12][13][14] Warming lignocaine to 37°C has been found to reduce significantly the pain of injection during peribulbar local anaesthesia. [15,16]Simpler method has been describedin literatures for warming local anesthetic solution which may cause a change in the pKa resulting in more rapid onset of neuronal blockade. ...
Article
Full-text available
To know the exact amount of 7.5%W/V B.P sodium bicarbonate (NaHCO3)necessary to getbufferingpH of 2% lignocaine without adrenaline ,with 1:80,000 adrenaline and with 1:2,00,000 adrenaline. Methodology : 10 ml of Type:1 (2% lignocaine without adrenaline), Type:2(2% lignocaine with 1:80,000) and Type:3 (2% lignocaine with 1:2,00,000 adrenaline ) were selected for study. In laboratory 7.5% W/V BP NaHCO3 was added in each anesthetic solution until pH of each mixture reaches body physiologic pH-7.2.pH was measured with pH measurement strips and confirmed by digital pH meter. Same procedure was performed for ten time and mean value was obtained. Result: It was found that required amount of 7.5% W/V B.P NaHCO3to get physiologic pH of local anesthetic solution was 1.6ml for Type:1, 2.1ml for Type:2 and 2.5ml for Type:3. Solution got precipitated at 0.4ml , 1.9ml, 2ml of 7.5% W/V BP NaHCO3for Type:1, Type:2 and Type:3 respectively. Conclusion: Precise amount of buffering agent require to obtain buffered pH of local anesthetic solution is 0.1ml for Type:1, 1.8ml for Type:2, 1.5ml for Type:3. These values are just smaller value at which solution get precipitates. There is no major pH changes for Type:1. So it is not advisable to buffer Type:1 local anesthetic solution. Anesthetic – to – bicarbonate solution ratio is 10:1.8 for Type:2 and 10:1.5ml for Type:3. Further study may be required to validate our results.
... [10] Various authors havefound that anesthetic formulations with higher pH values had faster onset. [10][11][12][13][14] Warming lignocaine to 37°C has been found to reduce significantly the pain of injection during peribulbar local anaesthesia. [15,16]Simpler method has been describedin literatures for warming local anesthetic solution which may cause a change in the pKa resulting in more rapid onset of neuronal blockade. ...
Article
Full-text available
Purpose: To know the exact amount of 7.5%W/V B.P sodium bicarbonate (NaHCO 3)necessary to getbufferingpH of 2% lignocaine without adrenaline ,with 1:80,000 adrenaline and with 1:2,00,000 adrenaline. Methodology : 10 ml of Type:1 (2% lignocaine without adrenaline), Type:2(2% lignocaine with 1:80,000) and Type:3 (2% lignocaine with 1:2,00,000 adrenaline) were selected for study. In laboratory 7.5% W/V BP NaHCO 3 was added in each anesthetic solution until pH of each mixture reaches body physiologic pH-7.2.pH was measured with pH measurement strips and confirmed by digital pH meter. Same procedure was performed for ten time and mean value was obtained. Result: It was found that required amount of 7.5% W/V B.P NaHCO 3 to get physiologic pH of local anesthetic solution was 1.6ml for Type:1, 2.1ml for Type:2 and 2.5ml for Type:3. Solution got precipitated at 0.4ml , 1.9ml, 2ml of 7.5% W/V BP NaHCO 3 for Type:1, Type:2 and Type:3 respectively. Conclusion: Precise amount of buffering agent require to obtain buffered pH of local anesthetic solution is 0.1ml for Type:1, 1.8ml for Type:2, 1.5ml for Type:3. These values are just smaller value at which solution get precipitates. There is no major pH changes for Type:1. So it is not advisable to buffer Type:1 local anesthetic solution. Anesthetic – to – bicarbonate solution ratio is 10:1.8 for Type:2 and 10:1.5ml for Type:3. Further study may be required to validate our results.
... This gelling system was merely induced by the temperature change, and was produced without the application of organic solvent and chemical cross-linking agent, thus avoiding the additional toxicity to human body. The formulation was heated and subcutaneously injected within the injectable temperature window acceptable by human body (Alonso et al., 1993;Hashmi and Davis, 2010). In this study, paliperidone (PAL), which was stable during the preparation (Kumar and Randhawa, 2013). ...
Article
Novel biodegradable in situ forming organogel, obtained via the self-assembly of long chain fatty acid in pharmaceutical oil, was prepared and characterized. Different from traditional organogels, the use of organic solvent was avoided in this gel system, in consideration of its tissue irritation. Four kinds of fatty acids were employed as organogelators, which could successfully gel with injectable soybean oil. The gelation procedure was thermo-reversible. Phase transition temperature and time were depended on carbon chain length and concentration of gelators. Optimized formulations containing drug were then injected subcutaneously in rats for pharmacokinetic study. Results showed the steady drug release for one week with the well-controlled burst, which fitted well with the drug release mechanism of both drug diffusion and frame erosion. In vivo imaging of the organogel with fluorescence in live animals suggested that the organogel matrix was gradually absorbed and completely up-taken in nine days. Histopathological analysis of the surrounding tissues was carried out and revealed an overall good biocompatibility property of the implants over drug release period. This research demonstrates that this thermo-sensitive in situ forming organogel system represents a potentially promising platform for sustained drug delivery.
... 4 A further study of 136 patients undergoing facial injection with 2% procaine demonstrated a statisti cally significant linear correlation between mean pain score and temperature of local anaesthetic between 10°C and 42 0c. 5 The mechanism by which warming reduces discomfort is not clear but there are several possible explanations. A colder solution may cause greater nociceptor stimulation. ...
Article
Eye is the official journal of the Royal College of Ophthalmologists. It aims to provide the practising ophthalmologist with information on the latest clinical and laboratory-based research.
... Bell et al (1996) and Alonso et al (1993) ...
Article
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Local anaesthetics (LAs) are used by medical practitioners in a number of clinical settings. The choice of agent and mode of administration is influenced by their experience, speciality and knowledge of the evidence base. Patients often express concern about the discomfort experienced during injection. Although short lived, the pain of LA administration in some patients is severe enough for them to decline future surgery. Methods to minimise the pain of LA administration relate to (1) the patient, (2) the LA, and (3) the injection technique (table 1). This article aims to provide a practical guide to doctors of all specialities who use LAs.
Article
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Background Both precooling the site and injecting a warm anesthetic solution have proven to be efficient in reducing pain individually. However, there is insufficient data on evaluating the efficiency of precooling the site of injection along with the simultaneous administration of a warm local anesthetic solution on the same site in a single patient. Aim The aim of this study was to evaluate and compare the efficacy, pain perception, hemodynamic changes, and adverse effects of a warm local anesthetic solution injected on precooled injection sites using 2% lignocaine with the conventional local anesthetic technique during inferior alveolar nerve block in 7–9-year-old children. Methods A split-mouth, double-blinded, randomized clinical trial was conducted on 70 children who received 2% lignocaine with either technique A or B during the first or second appointment of the treatment procedure. The pain perception, anesthetic efficacy, pulse rate, oxygen saturation levels, and adverse events were evaluated. Results Pain during injection and treatment after administration of the warm local anesthesia (LA) technique was less as compared to the conventional block technique. Anesthetic success was observed with a faster onset of action (212.57 ± 32.51 s) and shorter duration of LA (165.16 ± 33.09 min) in the warm local technique as compared to the conventional technique. No significant differences were found with regard to heart rate and oxygen saturation levels between the two techniques. Administrating warm LA solutions at precooled injection sites revealed fewer adverse events. Conclusion Injecting warm LA solution on precooled injection sites causes less discomfort and anxiety in children, which makes it more suitable for the child as well as the pediatric dentist.
Article
This study was conducted to compare the effects of heat preservation by two recommended methods, heated infiltration solutions and forced-air heating blankets, in patients undergoing liposuction under general anesthesia. Forty patients were divided into four groups based on whether heated infiltration solutions or forced-air heating blankets were used. Group A received general anesthesia liposuction plastic surgery routine temperature care. Based on the care measures of group A, heated infiltration solutions were used in group B; forced-air heating blanket was used in group C; and heated infiltration solutions and forced-air heating blankets were both used in group D. The primary end point was intraoperative and perioperative temperature measured with an infrared tympanic membrane thermometer. Secondary end points included surgical outcomes, subjective experience, and adverse events. Compared with group A, the intraoperative body temperatures of groups B, C, and D were significantly higher, indicating that the two intervention methods were helpful on increasing the core body temperature. Pairwise comparisons of these three groups showed that there was no significant difference between group C and group D. However, using forced-air heating blankets had a marked effect compared with using heated infiltration solutions alone at three time points. The same trend could be seen in other surgical outcomes. Heated infiltration solutions and forced-air heating blankets could reduce the incidence of intraoperative hypothermia and improve patients’ prognosis after liposuction under general anesthesia. Compared with the heated infiltration fluid, the forced-air heating blanket may have a better thermal insulation effect. This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266.
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Background: The efficacy of 2% lignocaine is reduced in a hot tooth. Local aesthetic agents can be preheated and buffered to increase their effectiveness. The present investigation was carried out due to limited information concerning adult patients with symptomatic irreversible pulpitis in mandibular teeth. Methods: A total of 252 individuals were included in the clinical trial in accordance with the selection criteria only after clinical study was registered with the Clinical Trial Registry of India (CTRI/2020/09/027796). Scores on the visual analog scale (VAS) and electric pulp test (EPT) on a 1-10 scale were recorded prior to the commencement of therapy. In this double-blinded study, patients were randomly divided by a co-investigator using computer randomisation (www.randomizer.org) into three groups, group A: inferior alveolar nerve blocks (IANB) with 2% lignocaine preheated at 42 °C (injected at 37 °C) (N = 84), group B: IANB of 2% lignocaine buffered with 0.18 ml of 8.4% sodium bicarbonate (N = 80) and group C: 2% lignocaine (N = 88). Excluding the dropouts of individuals (n = 11), wherein the anaesthesia failed, a total of 241 people were finally assessed 15 minutes after profound anaesthesia, endodontic access, and intraoperative pain were quantified using VAS. Pain on injection for all three groups was recorded immediately after IANB with VAS. The analysis was performed using one way ANOVA with Tukey's post hoc test and Paired T-Test using SPSS version 21. Results: Preheated, Buffered, and conventional 2% lignocaine showed statistically significant reduction in intraoperative pain (P < 0.001) compared to pre-operative but on inter-group comparison preheated and buffered showed highly significant pain reduction compared with conventional 2% lignocaine (P < 0.001). Conclusions: Warm and buffered local anaesthetic (LA) were effective in reducing intraoperative discomfort than conventional LA. Preheated local anesthetics caused the least pain, followed by buffered local anesthetics, while conventional local anesthetics caused the most pain.
Chapter
The proficient performance of arthrocentesis and soft tissue injections are foundational skills for the rheumatologist. Beyond the requirements for the use of sterile equipment, skin antisepsis, and aseptic practice, there are many procedural options that contribute to significant individual practice variation. The common technical aspects of these procedures are reviewed, including indications and contraindications, risks, hardware selection, anesthetics, and injectates.KeywordsArthrocentesisIntraarticular procedureCorticosteroid injection
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Objective/background Endovenous thermal ablation (EVTA) is the recommended first line intervention for superficial venous incompetence (SVI). While the infiltration of perivenous tumescent local anaesthesia (TLA) is key to procedural success, it is paradoxically the predominant source of patient reported discomfort. This randomised controlled trial investigates the potential to reduce peri-procedural pain and improve patient reported outcome measures (PROMs), including quality of life (QoL) using TLA buffered to physiological pH. Methods Patients undergoing great saphenous vein EVTA with concomitant phlebectomies were randomised to either standard (ST) or buffered (BT) TLA. Follow up assessments were performed at weeks 1, 6, and 12. The primary outcome was patient reported peri-procedural pain on a 100 mm visual analogue scale (VAS). Secondary outcomes were one week post-procedural pain VAS and analgesia use, QoL (disease specific: Aberdeen Varicose Vein Questionnaire [AVVQ]; generic: Short Form-36 [SF-36] and EuroQol 5 Dimensions Questionnaire [EQ-5D]), patient satisfaction VAS, technical success on duplex ultrasound (DUS) examination, and complications. Results Ninety-seven patients were randomised: 50 to ST and 47 to BT. The groups had comparable baseline demographics, Clinical Etiologic Anatomic Pathological, Venous Clinical Severity Score, QoL, and DUS parameters. Equally, intra-procedural parameters (volume of TLA, length of ablation, and linear energy delivered) were also comparable. Peri-procedural pain scores were significantly lower in the BT group with a mean ± SD score of 2.86 ± 3.57 versus 4.44 ± 2.94 (p = .001). Pain scores and analgesia use over the subsequent week were equivalent. SF-36 Bodily Pain domain scores were significantly better in the BT group at week 1 (77 vs. 62; p = .008). AVVQ, SF-36, and EQ-5D scores were otherwise similar between the groups throughout follow up, significantly improving over baseline. Technical success was high in both groups, with no major complications and few minor complications. Conclusion Buffered TLA offers a significantly lower peri-procedural pain experience for patients undergoing EVTA and should replace current tumescent formulae.
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Background: Digital nerve block is associated with pain. In a search for methods to reduce the discomfort, we investigated how the volume of anaesthetic fluid influences pain during subcutaneous digital nerve block, and how it affects the success of the anaesthesia. Methods: A randomized blinded prospective study was performed on 36 healthy volunteers. The single injection subcutaneous digital block technique was used to anaesthetize the participants´ 4th digit on both hands. The same amount of lidocaine was used, but in two different volumes; 1 ml 2% lidocaine and 2ml 1% lidocaine. After each injection the participant was asked to estimate pain intensity on a visual analogue scale (VAS). The distribution of anaesthesia was then measured by using a Semmes-Weinstein 4.56 monofilament. Finally, participants gave a verbal assessment of which injection was least painful. Results: In total, 72 blocks were performed. There were no statistically significant differences in pain intensity or preference between the two groups. Furthermore, the 1 ml injection gave poorer anaesthesia and had longer time to onset. Neither injection anaesthetized the dorsal aspect of the proximal phalanx. Conclusions: The two volumes cause the same degree of discomfort. Greater volume gives a greater area of distribution and more rapid onset of anaesthesia. It seems unreasonable to use a smaller volume of more concentrated anaesthetic when performing the subcutaneous technique.
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Purpose: Warm local anesthetic solutions are suspected to reduce pain of injection. The authors assessed the effect of warming local anesthetic solutions on pain of injection and on bulbar akinesia and analgesia of retro-bulbar anesthesia (RBA). Methods: Seventy patients undergoing RBA for cataract surgery were enrolled into a prospective, double-blind trial. They were allocated randomly to receive 5 ml of either warm (37 ± 1°C) or cold (20 ± 1°C) anesthetic solution for RBA. Additionally, O’Brien’s method was used immediately before RBA to create akinesia of the orbicularis oculi muscle. The following data were collected additionally before and 20 minutes after retrobulbar injection: eye motility (Kestenbaum test) and corneal sensitivity at four different sites (0, no sensitivity; 1, sensitivity remaining). The pain of injection was registered using an ordinal analogous scale before and immediately after the injection. Results: The scores for injection pain (4.5 ± 2.3 points), horizontal eye motility (0.2 ± 0.8 mm), and vertical eye motility (0.9 ± 2.1 mm) were all lower for the warm group than the cold group (pain score 5.2 ± 2.6 points, horizontal eye motility 0.7 ± 1.6 mm, vertical eye motility 1.2 ± 2.0 mm). Two patients in the warm group and four patients in the cold group had remaining corneal sensitivity. None of the differences were significant. Conclusions: Our data indicate no significant difference in injection pain, bulbar analgesia and akinesia after RBA between warm and cold anesthetic solutions.
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In situ forming injectable biodegradable implants for subcutan or intramuscular administration offer many advantages for controlled drug delivery have become an alternative systems to common parenteral depot systems such as microspheres and standart implants. In this review; these newer implant systems were investigated with their depot formation mechanisms, materials used as depot components, preparation methods, applications, advantages and disadvantages.
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To investigate the effects of warming vs buffering, and warming with buffering, on the pain of lidocaine infiltration. A randomized, double-blind clinical trial was conducted using volunteers aged 18 years or more and without an allergy to lidocaine. The study consisted of two parts, each comparing two solutions. The solutions for Part I were warm (38.9 degrees C; 102 degrees F) plain lidocaine and room-temperature buffered lidocaine. Warm buffered lidocaine and room-temperature buffered lidocaine were used for Part II. The subjects received two standardized 0.5-mL intradermal injections, one study solution in each forearm. Immediately after each injection, pain was assessed using a 100-mm visual analog pain scale. Pain scores were analyzed by the sign test, with significance defined as p < 0.05. Part I (n = 10): Nine subjects reported room-temperature buffered lidocaine to be less painful than warm plain lidocaine. Mean pain scores were 28 mm lower for room-temperature buffered lidocaine than they were for warm plain lidocaine (p < 0.01). Part II (n = 24): Eleven subjects found warm buffered lidocaine to be the least painful, 11 reported room-temperature buffered lidocaine to be the least painful, and two reported no difference. A mean pain score difference of 2.1 mm favoring warm buffered lidocaine was not statistically significant. Part II had a power of 80% to detect a 10-mm difference between the two solutions at alpha = 0.05. To reduce the pain of lidocane infiltration, buffering is more effective than warming. Warming does not enhance buffering.
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Objective To determine whether the temperature of 2% lignocaine hydrochloride gel affects the initial discomfort during instillation into the male urethra.Patients and methodsSixty consenting men were randomized to receive 11 mL of 2% lignocaine hydrochloride gel (Instillagel, Farco-Pharma GmbH, Cologne, Germany) at 4°C, 22°C or 40°C. The three groups were well matched for age and numbers of previous flexible cystoscopies. The gel was instilled by one operator and the patients were then immediately asked to score the pain on instillation using a 100-mm nongraphical visual analogue scale.ResultsCompared with the control group (at 22°C), there was a statistically significant reduction in pain score in the group receiving cold gel (Student’s t-test, P<0.05).Conclusion The cooling of 2% lignocaine gel significantly reduced the initial discomfort associated with its delivery into the male urethra before any form of urethral instrumentation.
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Local anaesthetics produce pain and burning on subcutaneous infiltration. This transient discomfort often proves to be the most unpleasant aspect of minor surgical procedures. This study aimed to elucidate if warming local anaesthetic to 37°C reduces pain of digital injection. Thirty-six patients attending a department of podiatry for nail surgery participated in this randomized, double blind study. Pain levels were assessed utilizing a visual analogue scale. Each subject was randomly allocated to receive 1 ml of local anaesthetic at either 37°C or 5°C. Pain scores for warm local anaesthetic solution (median 2.6, upper quartile 6.1, lower quartile 1.5) were significantly less painful on digital injection than cold solution (median 9.3, upper quartile 11, lower quartile 8.2) which was confirmed by statistical analysis using SPSS for Windows (Wilcoxon's signed ranks test, matched pairs [z=−2.90, P=0.0038]).
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To determine the effects of warming and buffering of 0.5% bupivacaine on the pain associated with intradermal injection and the time of onset of anesthesia, 40 adult volunteers were entered into a randomized, double-blind study conducted at a community teaching hospital. The three-part study compared room temperature (20 degrees) bupivacaine buffered to a pH of 7.1 with the following solutions: buffered bupivacaine warmed to 37 degrees C, unbuffered bupivacaine at room temperature, and unbuffered bupivacaine warmed to 37 degrees C. The same crossover protocol was followed for each part of the study. Subjects received 0.5-mL intradermal injections through 27-gauge needles over 30 seconds, one study solution in each forearm. Immediately after each injection, pain was assessed using a 100-mm visual analog pain scale. The time of onset of anesthesia (loss of intradermal sensation to pinprick) was measured by stopwatch. The mean perceived pain score for the warm buffered bupivacaine (51 mm) was significantly lower than for the room temperature buffered solution (63 mm, P = .003). Similarly, there was a statistical difference between the room temperature buffered and unbuffered solutions (65 v 78 mm, P < .001). The differences in mean pain scores for the room temperature buffered bupivacaine, compared with the other three solutions, suggest that warming and buffering have an additive effect. In this model, the latency of action of bupivacaine was not affected by alkalinization. However, warming bupivacaine to 37 degrees C reduced the time of onset to intradermal anesthesia by 12.1 seconds (95% confidence interval, 0.6 to 23.6). These results suggest that warming is more effective than buffering to reduce the pain of infiltration of bupivacaine and the time of onset of intradermal anesthesia.
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The aim of this randomized controlled study was to determine whether administration of lignocaine with adrenaline is less painful when injected at room temperature compared to refrigerated temperature. A cohort of 50 patients undergoing unilateral carpal tunnel decompression was randomized to room temperature or refrigerated local anaesthetic. Pain scores were assessed using a 10 mm visual analogue scale. Mean pain scores were 4.0 (SD +/- 1.5) for room temperature and 6.5 (SD +/- 1.7) for refrigerated local anaesthetic (P < 0.001). This study demonstrates that patients experience greater pain levels with administration of local anaesthetic at refrigerated temperatures prior to open carpal tunnel release.
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Background: There is little published in the English literature on the use of very dilute solutions oflignocaine and adrenaline in general surgery. Methods: The author used 0.1 per cent lignocaine with 1:1,000,000 adrenaline in 328 patientsfollowing premedication with pethidine, chlorpromazine and diazepam. The response to surgery was evaluated using six categories. Results: Ninety three per cent of patients were categorized in the top three categories of perfect,excellent and very good. Good and fair categories were seen in seven patients. The "poor" category which meant conversion to endotracheal general anaesthesia was not recorded. Thediscussion section deals with the method of preparing the solution, technical considerations, relative contraindications, complications in 2 common operations, drawbacks of the technique andits advantages. Conclusion: Lignocaine 0.1% With Adrenaline1:1,000,000 solution is effective, inexpensive and safe.
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Subkütan veya intramüsküler uygulanan, in situ oluşan enjektabl biyoparçalanabilir implantlar, etkin maddelerin kontrollü salımı açısından birçok avantaj sunan, mikroküreler ve standart implantlar gibi genel parenteral depo sistemlerine alternatif olma yolunda olan sistemlerdir. Bu derlemede, bu yeni implant sistemler; depo oluşum mekanizmaları, depo oluşturmada kullanılan materyalleri, hazırlama yöntemleri, uygulamaları, avantajları ve dezavantajları açısından incelenmiştir.
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To determine whether warming of lidocaine decreases the pain of its injection during digital nerve block. Prospective, randomized, double-blind, controlled trial. Twenty healthy volunteers received bilateral digital nerve blocks of their middle finger. They were first randomly assigned to receive either room-temperature (21 degrees C) or heated (42 degrees C) 2% lidocaine in their first block. They were then randomly assigned to receive the first block in either the right or left hand. The blocks were performed in a standardized fashion by a single physician, who was blinded to which solution was being used. The volunteers rated the pain of each digital block on a 100-mm visual analog scale (VAS). Efficacy of each digital block was tested at 5 minutes. Heating of the lidocaine was associated with a significantly lower median VAS pain score (31.5 versus 25.0; P < .05). There was no difference in pain score between the two solutions in relation to which hand was used (P = .29) or whether the injection was the first or the second (P = .37). When all factors (temperature, order, and hand) were considered in the ANOVA with respect to VAS pain score, the only significant relation found was that between the temperature of the solution and the VAS pain score (P = .028). Heating of lidocaine decreases the pain of injection during digital nerve block.
Article
A prospective, randomised, double blind trial was carried out to test whether or not the application of topical anaesthetic cream (EMLA cream) before infiltration of local anaesthetic would decrease the discomfort of correction of prominent ears under local anaesthetic. 23 patients were entered into the trial. They acted as their own controls, one ear having EMLA cream applied approximately 2 h prior to surgery, and the other Aqueous cream. Immediately after surgery, the patients were asked to complete two scales describing the amount of pain they had felt in each ear, both at the time of injection of local anaesthetic and during the surgery. They were also asked whether they thought the inconvenience associated with the use of the EMLA cream was worth any improvement they felt. The results showed that, compared to the placebo cream, EMLA cream significantly decreased the pain felt both at the time of injection (p < 0.005) and during the surgery (p < 0.01). However, only 62% of patients asked felt that the inconvenience associated with the use of EMLA cream was worth the benefits that it conveyed.
Article
The most frequent complaint noted with the use of lidocaine (or other amide local anesthetic) is stinging or burning pain associated with subcutaneous infiltration. The purpose of this study was to evaluate the efficacy of warming buffered lidocaine for reducing the pain of infiltration. Forty adult volunteers were entered into a randomized, crossover study conducted at a community teaching hospital. Blinded subjects underwent 1-mL subcutaneous injections of the study agent through 27-gauge needles over 30 seconds. Following a crossover protocol, "room temperature" buffered lidocaine (20 degrees C) was injected into one midvolar forearm and "body temperature" buffered lidocaine (37 degrees C) into the opposite arm. The order and the handedness of the two injections were randomized; an independent observer prepared the anesthetic solutions. Pain was assessed using a 100-mm visual analog pain scale and subjects' comparison of pain on injection. Twenty subjects (50%) reported that 20 degrees C buffered lidocaine was more painful and 17 (42.5%) reported that the 37 degrees C solution was more painful (sign test, P = .74). Similarly, a median pain score difference of 5.0 mm favoring 37 degrees C lidocaine was not statistically significant (sign rank test, P = .42). The order or the initial side of the injection did not influence the pain scores. The study had a power of 80% to detect a 10-mm difference between the two solutions at alpha = .05. These results suggest that warming buffered lidocaine to body temperature (37 degrees C) does not reduce the pain of subcutaneous infiltration.
Article
Peribulbar anesthesia is the preferred technique of local anesthesia of the majority of cataract surgeons. Local anesthetic injections at other sites in the body have been shown to be less painful if the solution is warmed to body temperature before injection. To determine whether this is of advantage with peribulbar anesthesia, the authors performed a prospective, randomized, single, blind trial comparing local anesthetic injections that have been warmed to room temperature. Forty consecutive patients undergoing routine cataract surgery were randomized into two groups of 20 patients and received local anesthetic at 20 degrees C or 37 degrees C. The peribulbar injection contained a solution of 5 ml 2% Lignocaine, 5 ml 0.5% bupivicaine (Marcaine), and 1550 IU hyaluronidase (HYlase) in a 10-ml syringe on a 25-mm, 25-gauge needle. Seven milliliters of the final solution was injected transcutaneously at the junction of the lateral and medial thirds of the lower lid. The patients graded the pain of the injection using a visual analogue scale. The pain sensation of local anesthesia is less when the solution is warmed to body temperature compared with room temperature (P = 0.026, using an unpaired Student's t test). Warming the local anesthetic used in peribulbar anesthesia to body temperature before injection reduces this iatrogenic pain significantly.
Article
The effect of warming local anesthetic on the amount of pain experienced during local infiltration was tested by comparing equal volumes of 40 degrees C- and 21 degrees C-infiltrates in each of 26 subjects. Six subjects were patients undergoing excision of two benign asymptomatic nevi in separate locations, and 20 subjects were healthy adult volunteers who were injected in bilateral antebrachial sites. The warmed and room temperature solutions were randomized to each side, so that each subject received both temperature injections in random order. All subjects and the injector were blinded. The rate of injection was time-controlled (0.05 ml/sec). Following both injections, subjects were asked to rate the pain experienced at each site. In addition, the subject was asked if there was no difference, a slight difference, or a substantial difference between the two sites. A two-tailed paired t-test was used to analyze the mean difference in pain scores for all subjects. Paired analysis of the pain scores for each subject eliminated intersubject variance of pain tolerance. The mean difference in pain score between the room temperature and warmed solutions was +1.5 (p < 0.0001). Of the 21 subjects (81%) who found the warmed solution less painful, 11 (52%) found the difference to be significant, while 10 (48%) found the difference to be slight. Two subjects (8%) found no difference between the two, while 3 subjects (11%) found the colder solution slightly less painful. We conclude that warming local anesthetic to 40 degrees C prior to subcutaneous injection is a simple, inexpensive means of reducing the pain of local infiltration.
Article
The warming of local anaesthetic solutions to reduce the pain felt on injection is common practice in a number of medical sub-specialties. A study was undertaken to assess the effect of temperature on the discomfort caused by local anaesthetic eye drops. Tropical anaesthetics amethocaine 1%, oxybuprocaine 0.4% and lignocaine 4% were studied, and after the application of strict exclusion criteria 60 patients were selected, 20 patients for each anaesthetic. Each patient group received a topical anaesthetic at 42 degrees C in one eye and at room temperature in the other. A 10 point visual analogue scale was used to assess the discomfort experienced. No statistically significant difference was found between the discomfort caused by drops at each temperature for any of the three anaesthetics studied. There appears no benefit in warming topical anaesthetic agents prior to their use.
Article
The authors assess the effect of warming local anesthetic solutions on pain of injection and on bulbar akinesia and analgesia of retrobulbar anesthesia (RBA). Seventy patients undergoing RBA for cataract surgery were enrolled in a prospective, double-blind trial. They were allocated randomly to receive 5 ml either warm (37 degrees C) or cold (20 degrees C) anesthetic solution for RBA. Additionally, O'Brien's method was used to create an akinesia of the orbicularis oculi muscle. The following data were collected before and 20 minutes after retrobulbar injection: pain of injection, eye motility (Kestenbaum test), and corneal sensitivity (0: no sensitivity; 1: sensitivity remaining) at four different sites. The pain of injection was registered using an ordinal analogous scale before and immediately after the injection. Furthermore, data acquisition included any possible side effects and the bulbar length, measured with ultrasound. The score for injection pain (4.5 +/- 2.3 points), horizontal eye motility (0.2 +/- 0.8 mm), vertical eye motility (0.9 +/- 2.1 mm) all were lower for the warm group in comparison to the cold group (average pain score: 5.2 +/- 2.6 points; horizontal eye motility: 0.7 +/- 1.6 mm; vertical eye motility: 1.2 +/- 2.0 mm). Two patients in the warm group and four patients in the cold group had remaining corneal sensitivity. None of the differences were significant. Data indicate no significant difference in bulbar analgesia and akinesia after RBA between injections of warm and cold anesthetic solutions.
Article
Lasers are now well accepted as standard treatment for many cutaneous lesions. Many types of laser treatment require pain relief, the choices being general anaesthesia, (particularly in younger patients), or local or topical anaesthesia (EMLA). There have been few reports on the specific use of local anaesthetic nerve blocks in the laser treatment of cutaneous lesions. We present our experience of 816 nerve blocks in 135 patients (53 males, 82 females; age range 5-73 years, median 27 years) during 877 treatment sessions 96% of the nerve blocks provided complete anaesthesia in the required anatomical area. Only 9 (7%) patients (1.1% of the 816 nerve blocks) developed complications that could be attributed to the anaesthetic blockade. We recommend nerve blocks as a safe and efficacious method of anaesthesia during the laser treatment of cutaneous lesions.
Article
This study compared the pain from intradermal infiltration of (1) plain lidocaine, (2) warmed lidocaine, (3) buffered lidocaine, and (4) warmed, buffered lidocaine. A randomized, double-blind, Latin Square design of 20 volunteers was used. Each volunteer was injected with a series of four test solutions on four separate occasions, for 16 total injections each. Each volunteer served as his or her own control. The mean pain scores for the four solutions were: 44.2 for plain lidocaine, 42.2 for warmed lidocaine, 36.7 for buffered lidocaine, and 29.2 for warmed, buffered lidocaine. Buffered lidocaine was statistically less painful than both plain lidocaine and warmed lidocaine. Warmed, buffered lidocaine was significantly less painful than all other solutions, including buffered lidocaine (P < .005). However, warmed lidocaine did not yield pain scores significantly different from plain lidocaine. In this experimental model, warmed lidocaine was not superior to plain lidocaine, but warmed, buffered lidocaine caused significantly less pain than plain lidocaine, buffered lidocaine, or warmed lidocaine. Thus, there may be benefit from heating the buffered lidocaine now in common clinical use.
Article
To determine whether the temperature of 2% lignocaine hydrochloride gel affects the initial discomfort during instillation into the male urethra. Sixty consenting men were randomized to receive 11 mL of 2% lignocaine hydrochloride gel (Instillagel, Farco-Pharma GmbH, Cologne, Germany) at 4 degrees C, 22 degrees C or 40 degrees C. The three groups were well matched for age and numbers of previous flexible cystoscopies. The gel was instilled by one operator and the patients were then immediately asked to score the pain on instillation using a 100-mm nongraphical visual analogue scale. Compared with the control group (at 22 degrees C), there was a statistically significant reduction in pain score in the group receiving cold gel (Student's t-test, P<0.05). The cooling of 2% lignocaine gel significantly reduced the initial discomfort associated with its delivery into the male urethra before any form of urethral instrumentation.
Article
Biodegradable injectable in situ forming drug delivery systems represent an attractive alternative to microspheres and implants as parenteral depot systems. Their importance will grow as numerous proteins will lose their patent protection in the near future. These devices may offer attractive opportunities for protein delivery and could possibly extend the patent life of protein drugs. The controlled release of bioactive macromolecules via (semi-) solid in situ forming systems has a number of advantages, such as ease of administration, less complicated fabrication, and less stressful manufacturing conditions for sensitive drug molecules. For these reasons, a number of polymeric drug delivery systems with the ability to form a drug reservoir at the injection site are under investigation. Here, we review various strategies used for the preparation of in situ forming parenteral drug depots and their potential benefits/draw-backs, especially with regard to the delivery of protein drug candidates.
Article
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.
Article
: Bupivacaine is a preferred epidural anesthetic in obstetrics because it has a long duration of action and it causes minimal motor blockade. Its major disadvantage is its slow onset of action. This report outlines the use of warm bupivacaine to shorten the latent period of onset of action of bupivacaine while maintaining its properties of long duration of action and minimal motor blockade. (C)1987 American Society of Regional Anesthesia and Pain Medicine
Article
: A double-blind study was performed in which 0.5% bupivacaine with epinephrine 1:200,000 (pH 3.9) was compared with an alkalinized solution of bupivacaine (pH 6.4) for the production of brachial plexus blockade. Twenty to 30 ml of each solution (2 mg/kg) was used for brachial plexus blockade administered by the subclavian perivascular technique. The onset, depth, and duration of analgesia was determined. The results indicate that alkalinization of bupivacaine solution resuits in a more rapid onset of sensory analgesia and a prolonged duration of sensory analgesia. (C)1985 American Society of Regional Anesthesia and Pain Medicine
Article
The injection of local anaesthetic solutions is painful. We report the results of a blinded randomised controlled trial comparing the pain of injection of local anaesthetics at room temperature and body temperature. The results show that local anaesthetic solution injected at body temperature produces significantly less pain than local anaesthetic injected at room temperature.
Article
One hundred adult day-case patients who required intravenous access had cannulae inserted using local anaesthesia with 1% lignocaine, 1% lignocaine with adrenaline or the corresponding pH-adjusted solutions. The local anaesthetic solutions were modified by the addition of 1 ml 8.4% sodium bicarbonate to 10 ml lignocaine. Pain scores at different stages of cannulation were noted and showed a significant reduction after use of pH-adjusted solutions (p less than 0.02 for the plain lignocaine, and less than 0.001 for the lignocaine with adrenaline). Modification of the pH of lignocaine solutions by the addition of sodium bicarbonate is a simple method significantly to reduce the discomfort caused by the infiltration of the local anaesthetic.
Article
The effects of pH buffering on the pain of administration and efficacy of three local anesthetics (1% lidocaine, 1% lidocaine with 1:100,000 epinephrine, and 1% mepivacaine) were investigated in a randomized, prospective, double-blind study of 25 adult volunteers. Plain and buffered solutions of the three local anesthetics were prepared, and a 0.5 intradermal injection of each was administered. Pain of anesthetic infiltration was rated from zero to ten. The area of anesthetized skin surrounding each injection site was measured at time intervals following each injection. Buffering the local anesthetics significantly reduced the mean quantitative pain estimates compared to the nonbuffered controls: 1) 1% lidocaine compared with buffered 1% lidocaine, 4.9 +/- 0.4 versus 1.1 +/- 0.2 (P less than 10(-6)); 2) 1% lidocaine with epinephrine compared with buffered 1% lidocaine with epinephrine, 5.1 +/- 0.4 versus 1.8 +/- 0.4 (P less than 10(-6)); and 3) 1% mepivacaine compared with buffered 1% mepivacaine, 5.1 +/- 0.4 versus 0.9 +/- 0.2 (P less than 10(-6)). Onset, extent, and duration of skin anesthesia were not statistically altered by pH buffering. The pain of local anesthetic administration can be dramatically reduced by buffering the local anesthetic prior to its infiltration. Anesthetic efficacy is not compromised, and patient acceptance may be significantly increased.
Article
Anesthetics produce pain on skin infiltration (1,2). The relation of this local anesthetic-induced pain to pH of the local anesthetic solution has, however, not been evaluated. Commercial preparations of local anesthetics are prepared as acidic solutions of the salts to promote solubility and stability. Further increases of acidity in local anesthetic solutions containing epinephrine are avoided by the addition of epinephrine to plain lidocaine (3); sodium bicarbonate can also be used to increase pH. Such increases in pH, by increasing the ratio of nonionized to ionized local anesthetic, alter the pharmacologic properties of local anesthetics. For example, addition of sodium bicarbonate to preparations of local anesthetics increases spread and duration of sensory blockade and lessens the time to onset of anesthesia (4,5). The present double-blind, randomized study was designed to determine the relation between pH of anesthetic solutions and production of pain associated with infracutaneous injection of the local anesthetic, lidocaine.
Article
Local anesthesia by intradermal administration of lidocaine is employed in virtually all interventional radiologic procedures. Transient burning and/or pain are experienced by almost everyone who receives lidocaine by this route. An anecdotal report has recently been published that suggests that warming of lidocaine to 43 °C reduces or eliminates the pain associated with intradermal lidocaine injection. To verify this, we performed a prospective, blinded trial as described below. There was a preference for warm lidocaine over cold lidocaine for intradermal injection. The difference, however, was unimpressive and appeared to be influenced by individual variations in pain perception and by injector or arm preference.
Article
One hundred forty-eight adult patients having epidural anesthesia for cesarean section, postpartum tubal ligation, lower extremity orthopedic procedures, or lithotriptic therapy were assigned to five groups. Group 1 patients were given a commercially prepared 1.5% lidocaine solution with 1:200,000 epinephrine plus 1 ml of normal saline per 10 ml of lidocaine; the solution pH was 4.6. Group 2 patients were given commercially prepared 1.5% lidocaine solution plus 1:200,000 epinephrine, with 1 mEq (1 ml) NaHCO3 per 10 ml of lidocaine; the solution pH was 7.15. Group 3 patients received the commercial solution of 1.5% lidocaine with 1:200,000 epinephrine; the solution pH was 4.55. Group 4 patients were given a mixture of 18 ml of 2% lidocaine with 30 ml of 1.5% lidocaine, both commercially packaged with 1:200,000 epinephrine, plus 1 mEq (1 ml) of NaHCO3 added per 10 ml of solution; the solution pH was 7.2. Group 5 patients received 1.5% plain lidocaine to which epinephrine was added to a final concentration of 1:200,000; the solution pH was 6.35. Times of onset of analgesia (time between the completion of the anesthetic injection and loss of scratch sensation at the right hip (L-2 dermatome] and of surgical anesthesia (time between completion of injection and loss of discomfort following tetanic stimulation produced by a nerve stimulator applied to skin on the right hip) were significantly more rapid in the groups that received the pH-adjusted solutions (groups 4 and 2). Group 4 had the fastest mean onset time, 1.92 +/- 0.17 min, followed by group 2, 3.31 +/- 0.23 min.(ABSTRACT TRUNCATED AT 250 WORDS)