Lidocaine v bupivacaine in facial plastic surgery. A clinical trial

The ideal local anesthetic agent for facial plastic surgery should have rapid onset, good surgical anesthesia, and reasonably long duration. The purpose of this prospective, randomized, double-blind study was to compare 1% lidocaine hydrochloride with 1:200,000 epinephrine with 0.5% bupivacaine hydrochloride with 1:200,000 epinephrine, a newer, longer-acting local anesthetic, in different facial operations. The results suggest that bupivacaine is an effective and safe agent for these procedures.     

Local anesthesia in rhinoplasty: a new twist?

Twenty volunteers were asked to compare pain upon injection during septorhinoplasty using buffered versus unbuffered local anesthetics. The concentration of the buffer was one part sodium bicarbonate to five parts local. The surgeons performing the operation were asked to identify any difference in hemostasis or duration of anesthesia. Eighteen of twenty 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 solution, however, faster onset of action was noted with the buffered solution. The addition of sodium bicarbonate as a buffering agent to the local anesthetics lidocaine and bupivacaine can significantly reduce pain upon injection. A solution of 5cc 2% lidocaine with 1:100,000 epinephrine, 5cc 0.25% bupivacaine with 1:200,000 epinephrine, and 2cc of 7.5% sodium bicarbonate mixed just prior to injection is a safe, effective, less painful local anesthetic with rapid onset of action and full efficacy.     

Structural effects of the topical lidocaine-prilocaine anesthetic Emla on the tympanic membrane

A eutectic mixture of two anesthetic solutions is that of lidocaine and prilocaine, which is available commercially as Emla (eutectic mixture of local anesthetics). This solution is commonly used in clinics in superficial skin surgery and when inserting intravenous catheters, and we also wanted to determine its surface effects when applied onto the tympanic membranes (TM) of rats and guinea pigs as animal models. The animals were observed by otomicroscopy for 2 weeks up to 5 months after administrations of the anesthetic solution. Tissue specimens were then obtained for light microscopy and fine structural analysis. The application of Emla caused minor structural changes to the rat TM, but hardly any alterations to that of the guinea pig. The changes displayed were an overall increased thickness, with typical submucosal edema but only slight epithelial reaction. In comparison with previous results with lidocaine, phenol and Bonain's solution, Emla seemed to be harmless to the structure of the TM. However, the efficacy of Emla as a topical TM anesthetic remains to be proved in future clinical trials.     

Myringotomy under topical anesthesia with phenol

Myringotomy is a common outpatient surgical procedure. It can be performed under general inhaled anesthesia, but it is usually carried out under local anesthesia by lidocaine infiltration or instillation of different anesthetic agents. We present our experience with myringotomy and tympanic tube placement using topical anesthesia with 88% phenol as an outpatient procedure. We report 55 patients in which we performed 81 treatments. In this series, only two ears (2.47%) did not tolerate the surgical procedure, tube insertion under general anesthesia being necessary in one case. Topical anesthesia with phenol facilitates the outpatient treatment of adult otitis media with effusion.     

Treatment of cochlear tinnitus with transtympanic infusion of 4% lidocaine into the tympanic cavity

Tinnitus is an otological symptom that is encountered often, yet its treatment is difficult. If tinnitus is of cochlear origin, a reasonable assumption is that a total depression of the cochlear function will abolish cochlear tinnitus. To achieve this depression, transtympanic infusion of a local anesthetic (4% lidocaine) to anesthetize the inner ear was conducted in a patient suffering from tinnitus. Transtympanic infusion of 4% lidocaine was performed as a treatment for cochlear tinnitus, and its efficacy was investigated. The overall efficacy rate for the 292 patients with 369 affected ears was 81%. In the investigation of the treatment results in cases of different underlying ear diseases, the efficacy rate was high for tinnitus accompanying sudden deafness and labyrinthine vertigo. However, vestibular symptoms, such as vertigo and nausea, developed after lidocaine infusion. No permanent side effects were noted. Lidocaine infusion is thought to be a useful treatment option for tinnitus and should be considered before surgical treatment. Inner ear anesthesia into the tympanic cavity has been carried out in patients who had cochlear tinnitus and in whom conservative methods of therapy, such as oral medication, had proved unsuccessful. This treatment method is useful as a local therapy for cochlear tinnitus.     

Use of dilute epinephrine as an aid in facial nerve monitoring.

Facial nerve monitoring during otologic and neurotologic procedures has been previously described, and its use is becoming routine. Although these procedures are done under general anesthesia, lidocaine is often used as a vehicle for epinephrine to aid hemostasis during the procedure. The routine use of lidocaine in these preparations presents the theoretical and sometimes real problem of anesthetizing the facial nerve at the start of the procedure, thereby invalidating subsequent attempts at monitoring and stimulation. We present the data from our experience with 74 patients using an epinephrine solution 1:100,000 for infiltration without any local anesthetic. We have found this procedure to be effective in maintaining hemostasis, quite safe and well tolerated, and without adverse effects on the desired monitoring of the facial nerve.     

Dose response of topical anesthetic on laryngeal neuromuscular electrical transmission

OBJECTIVES: Our purpose was to determine the effect of a dose response to decreasing concentrations of topical anesthetic upon laryngeal neuromuscular electrical transmission. METHODS: We performed a prospective study at a neurolaryngology referral center. Forty-three patients were divided into 5 groups. Each patient underwent laryngeal electromyography (EMG) of a thyroarytenoid muscle before and 60 seconds after topical laryngotracheal lidocaine hydrochloride, normal saline solution, or nothing was applied. The pretreatment and posttreatment measurements were recorded with the same indwelling EMG electrode. Group 1 (n = 12) received 4% lidocaine, group 2 (n = 9) received 2% lidocaine, and group 3 (n = 8) received 1% lidocaine. Group 4 (n = 5) received topical normal saline solution instead of lidocaine. A fifth group (group 5, n = 9) had 2 EMG recordings measured, each separated by 60 seconds, without topical anesthetic. RESULTS: Groups 1, 2, and 3 showed significant decreases in the maximum peak-to-peak amplitude of the EMG recording (48.5%, 49.7%, 44.7%, respectively). Groups 4 and 5 failed to show a significant change in peak-to-peak amplitude after 60 seconds. There was no dose response change in EMG with decreasing lidocaine concentrations. CONCLUSIONS: All concentrations of lidocaine administered in this study decreased the laryngeal neuromuscular electrical transmission as measured by laryngeal EMG. This group of patients did not exhibit any dose response to anesthetic concentration. This finding is clinically significant for both diagnostic and therapeutic uses of laryngeal EMG preceded by administration of topical anesthetic.     

Zur Ototoxizität von Lokalanästhetika. Eine tierexperimentelle Studie

Summary In 67 guinea pigs, the compound action potentials and cochlear microphonics were led off over a period of 8 days via an indwelling electrode after the bulla tympanica of the animals had been perfused with 1% local anesthetic solutions (tetracaine, lidocaine with and without epinephrine). At first there was a reversible reduction in the functional capacity of the internal ear. A subsequent short recovery phase was followed by an irreversible constant loss of hearing.     

Does topical lidocaine with adrenaline have an effect on morbidity in pediatric tonsillectomy?

OBJECTIVE: To evaluate the efficacy of lidocaine with adrenaline on post-operative morbidity in pediatric patients after tonsillectomy. STUDY DESIGN: A double blind prospective randomized controlled clinical study. METHODS: The study is consisting of two groups of pediatric patients following tonsillectomy performed in a university hospital. One group received lidocaine with adrenaline soaked swabs packed in their tonsillar fossae while the control group received saline-soaked swabs. Chi-square and two-tailed unpaired Student's t-tests were used to compare the two independent groups. p<0.05 was accepted as statistically significant. RESULTS: No significant pain-relieving effect was seen in the lidocaine with adrenaline group (p>0.05) and also the other post-operative parameters such as nausea, fever, vomiting, odor, bleeding, otalgia and trismus were not statistically different between the two groups based on chi-square analysis (p>0.05). There were no complications associated with lidocaine and adrenaline. CONCLUSION: We suggest that application of topical lidocaine with adrenaline seems to be a safe and easy medication for local anesthetic use. However, in our study, lidocaine with adrenaline offered no advantage over placebo in the control of post-operative pain and other morbidity related factors following pediatric tonsillectomy. We therefore do not recommend topical application of lidocaine with adrenaline for reducing morbidity in pediatric tonsil surgery.     

EMLA® cream as local anesthetic for radiofrequency turbinate tissue reduction

Radiofrequency volumetric tissue reduction is a minimally invasive technique in the treatment of turbinate hypertrophy and is generally performed under local anesthesia. However, perioperative discomfort and pain are common side effects and studies concerning the technique of choice to anesthetize the nasal mucosa in this procedure are lacking. The aim of this prospective controlled trial is to assess the effectiveness of EMLA^® cream as a topical anesthetic for radiofrequency volumetric tissue reduction of inferior turbinates comparing its effect with that obtained using a traditional anesthetic technique. 200 consecutive patients undergoing volumetric tissue reduction with topical anesthesia were enrolled. Patients were divided into two groups: Group A included 100 patients treated by placing cotton pledgets soaked with lidocaine 10 % in the inferior meatus followed by the injection of 2 % lidocaine into the head of the inferior turbinate; Group B included 100 patients treated with EMLA^® cream. Patients were evaluated before and after surgery using rhinomanometry for obstructive symptoms. Four VAS about pain, troublesome swallowing, choking sensation and intraoperative anxiety were submitted to each patient immediately after surgery and after 2 months to assess various aspects of perioperative discomfort. A significant increase of nasal airflow was observed without differences between the two groups. Subjective evaluation regarding perioperative discomfort showed significant differences between Groups A and B immediately after surgery although it was less pronounced 2 months later. The results of this study suggest that EMLA^® cream is an efficient tool in obtaining an adequate anesthetic effect in this procedure.     

Structural effects of the topical lidocaine-prilocaine anesthetic Emla on the tympanic membrane

Summary A eutectic mixture of two anesthetic solutions is that of lidocaine and prilocaine, which is available commercially as Emla (eutectic mixture of local anesthetics). This solution is commonly used in clinics in superficial skin surgery and when inserting intravenous catheters, and we also wanted to determine its surface effects when applied onto the tympanic membranes (TM) of rats and guinea pigs as animal models. The animals were observed by otomicroscopy for 2 weeks up to 5 months after administrations of the anesthetic solution. Tissue specimens were then obtained for light microscopy and fine structural analysis. The application of Emla caused minor structural changes to the rat TM, but hardly any alterations to that of the guinea pig. The changes displayed were an overall increased thickness, with typical submucosal edema but only slight epithelial reaction. In comparison with previous results with lidocaine, phenol and Bonain's solution, Emla seemed to be harmless to the structure of the TM. However, the efficacy of Emla as a topical TM anesthetic remains to be proved in future clinical trials.     

Bupivacaine for Postoperative Analgesia Following Endoscopic Sinus Surgery

This prospective study was conducted to examine pain after endoscopic sinus surgery (ESS). The hypothesis was that a long-acting anesthetic agent would result in patients experiencing less pain in the 24-hour postoperative period and therefore needing fewer oral analgesics. We randomized 100 patients undergoing ESS to receive either lidocaine (1% or 2%) with epinephrine or bupivacaine (0.25% or 0.5%) with epinephrine as an anesthetic and for a sphenopalatine block. Postoperative pain was assessed with a standard numeric pain assessment scale at baseline and at 2, 6, and 24 hours after surgery. The use of analgesics during this period was also documented. We compared the results between patients receiving bupivacaine and those receiving lidocaine, as well as between patients who required nasal packing and those who did not. We discovered that in general, pain after ESS was less severe than expected. We further found that the type of anesthetic used did not significantly affect postoperative pain; pain score changes and use of analgesics were similar between the two anesthesia groups. Postoperative pain was also similar between the “packing” and “no packing” groups. Although patients receiving packing had consistently lower increases in pain (and in fact many patients in this group had decreases in pain from baseline), none of the differences between group means was statistically significant.     

Toxicity of topical administration of lidocaine

It is frequently described in international literature the possibility of toxicity by local anesthesics. The lidocaine is one of them. The problems with its local use are more frequent and known but topic toxicity is also possible. We want to describe a case of toxicity by topical administration of lidocaine (Xylocain) which caused neurological disease with convulsions, and cardiological disease with ventricular fibrillation, in a patient who came for a thyroplasty. Patient's evolution was satisfactory.     

Experimental basis for lidocaine therapy in cochlear disorders.

In order to further our basic understanding of the effects of lidocaine hydrochloride in the inner ear, cochlear potentials and blood flow (CBF) were assessed after intravenous (i.v.), anterior inferior cerebellar artery (AICA), and local round window (RW) lidocaine administrations in guinea pigs and rats. Lidocaine RW applications produced a dose dependent decrease in compound action potentials (CAP) and cochlear microphonics (CM). The sensitivity changes were more pronounced at high frequencies. These findings suggest that lidocaine has specific pharmacological action in the inner ear other than simple anesthesia of the auditory nerve. The basal turn endocochlear potentials (EP) were not altered by topical lidocaine, implicating altered organ of Corti function following local application of lidocaine. RW applications of lidocaine had no effect on CBF or systemic blood pressure (BP). I.v. infusions caused substantial reductions in BP. In the case of systemic infusions the percent changes in CBF were equal to and accountable by the BP changes. The microinfusions (50 mg/ml, 100 nl/min) through AICA produced a 30%, long lasting increase in CBF. However, neither systemic lidocaine nor AICA infusions had an effect on CAP or CM. These findings indicate that systemically given lidocaine may not cross the blood-cochlear barrier and that the cochlear electrophysiological effects due to lidocaine when given locally are partly mediated by direct influence on cochlear hair cell function; they also suggest that lidocaine-induced interference with active ion transport in the lateral wall or an influence on CBF are not contributing factors.     

Electrophysiological effects of the clinically used local anesthetics lidocaine,lidocaine-prilocaine and phenol on the rat's inner ear

Summary Local anesthetics, even if applied to the outer ear canal, may still enter the middle ear, running the risk of penetrating the round window. To elucidate the effect of certain topical anesthetics on the inner ear, the round window niche in the laboratory rat's middle ear was exposed separately to lidocaine, lidocaine-prilocaine and phenol. Auditory brain-stem responses (ABR) were recorded at 2, 4, 6, 8, 12, 16, 20, and 31.5 kHz before the application, and 24 h, 3 weeks, 2 months and 6 months after exposure. After terminating the 6-month ABR measurements, the animals were sacrificed and the temporal bones fixed and decalcified for light microscopic analysis. All three drugs affected the ABR thresholds and the cochlear morphology with a pattern characteristic for each drug. At 24 h, all three substances caused severe impairment of ABR thresholds, followed by a period of restitution lasting up to 2 months. Even 6 months after exposure, the ABR thresholds at and above 12 kHz were impaired, as compared with the pre-treatment level, for all substances tested. In the lower frequencies the original ABR threshold was reached in the order: (1) lidocaine, (2) lidocaine-prilocaine, (3) phenol. The cochlear structures were unaffected by lidocaine, whereas lidocaine-prilocaine and phenol caused morphological damage which was most pronounced after exposure to phenol. The heterogeneity of the changes in the ABR thresholds suggests differences in the mechanism of action of each type of local anesthetic investigated. The effects following lidocaine were transient. However, clinicians must be aware of the ototoxic potential of both lidocaine and phenol.     

The effects of dexamethasone and levobupivacaine on postoperative pain in Modified Radiofrequency Assisted Uvulopalatoplasty (MRAUP) surgery

The objective of this prospective, randomized study was to evaluate the effect of pre-emptive local infiltration of lidocaine, lidocaine plus dexamethasone, levobupivacaine and levobupivacaine plus dexamethasone on postoperative pain in Modified Radiofrequency Assisted Uvulopalatoplasty (MRAUP) cases. Sixty adult patients (44 males and 16 females) aged 32–51 years with simple snoring were divided into four groups. The anesthesia of the patients in the first group was achieved with lidocaine HCl, in the second group, with lidocaine HCl and dexamethasone sodium phosphate, in the third group, with levobupivacaine, and in the fourth group, levobupivacaine and dexamethasone sodium phosphate. All the patients were applied Modified Radiofrequency Assisted Uvulopalatoplasty technique. The pain experienced by the patients during swallowing and at rest on the 1st, 3rd, 5th, 7th, and 10th day and analgesic consumption were evaluated using standard 10 cm visual analog scales. The mean duration of operation in the group that received lidocaine HCl was 22 ± 3 min, while in the group that received levobupivacaine HCl was 27 ± 4 min. There were statistically significant differences between the groups for analgesic effects on the 1st, 3rd, 5th, and 7th day and for the amount of analgesics used, on the 1st, 3rd, and 5th day. The best results were obtained in the group that received levobupivacaine HCl and steroid (p < 0.001). Steroid and local anesthetic combinations are superior to controls in the management of postoperative pain in MRAUP surgery.     

Late effects of topical anesthetics on the healing of guinea pig tympanic membranes after myringotomy

BACKGROUND: The optimal local anesthetic for myringotomies or the insertion of tympanostomy tubes in adults should be easy and rapid to use, be painless during application, provide good anesthesia, be reversible, be inexpensive, and not cause any long-term damage to the tympanic membrane (TM). OBJECTIVE: To evaluate the histologic effects of topical anesthetic agents on the healing of the TM after myringotomy. METHODS: Sixty male albino guinea pigs were randomly assigned to 1 of 5 groups. Of the 5 groups, 2 were used as controls: one group underwent a myringotomy and the other group did not. The remaining 3 groups had both TMs treated with a topical anesthetic (phenol, tetracaine base, and eutectic mixture of lidocaine and prilocaine in a cream) prior to myringotomy. All TMs were inspected periodically and then harvested at 3 months or 6 months postoperatively for histologic examination. RESULTS: The TMs of the group treated with tetracaine appeared the most normal at 6 months (P=.001). However, histologic evaluation failed to demonstrate any significant differences in the thickness of the TM or the lamina propria (P=.45), the amount (P=.80) and orientation (P=.07) of collagen, or the number of infiltrating lymphocytes (P=.70). CONCLUSION: Based on the histologic findings, all 3 topical anesthetic agents appear to cause equivalent changes to the TM when used for a myringotomy.     

Clinical utility of local over general anesthetic tonsillectomy using the BiZact™ device

PurposeTonsillectomy under general anesthesia may be viewed preferentially to local anesthesia, due to mitigation of potential airway compromise secondary to intraoperative hemorrhage, patient discomfort and anxiety. However, this is offset by risk of increased trauma (via the endotracheal tube and gag), adverse medication reactions and cost. Here we evaluated the case for use of local anesthesia in tonsillectomy using the BiZact? (Medtronic) device by comparing surgical outcomes and cost factors across patients where either local or general anesthesia was employed.Materials and methodsRetrospective cohort study of 59 BiZact? tonsillectomy patients (38 under local anesthetic, and 21 under general anesthetic) from a single surgeon at Tauranga Hospital (public) and Grace Hospital (private) in New Zealand; March 2018 to June 2021.ResultsNeither patient group had any primary postoperative hemorrhage and there was comparable incidence of secondary hemorrhage (one case in each cohort). Local anesthetic tonsillectomy was well tolerated with only 2 patients requiring conversion to general anesthetic secondary to anxiety. Local anesthetic proved to be cost-effective, with a halving of hospital length of stay and significant associated overall cost saving, and did not add significantly to operating or total theatre time. Local anesthetic tonsillectomies where perioperative sedation was not required were associated with additional reductions in recovery and overall hospital stay, and cost.ConclusionsLocal anesthetic BiZact? tonsillectomy is evidently safe and cost-effective.     

Nasal nitric oxide is not altered by topical anesthesia

This prospective study was undertaken to determine whether topical nasal anesthetic agents affect nasal nitric oxide (NO) output in healthy adults. Seven volunteers (aged: 29-56 (40.6 +/- 10.7) years, six male), were recruited. A topical anesthetic (4% lidocaine or 0.5% tetracaine) was sprayed into the subject's right nostril while the left nostril served as a control. Unilateral nasal NO and nasal volume were measured before administration of the anesthetic and at 15 and 30 minutes after the administration. The mean (+/- SD) unilateral nasal NO output was 307 +/- 45.9 nL/minute from the right nostril (exposure side) before the topical application of lidocaine. At 30 minutes after topical application (n = 6), it was 295.5 +/- 41.5 in the right nostril and 297.5 +/- 39.8 in the left (control side). In the tetracaine group (n = 7), the mean (+/- SD) unilateral nasal NO output was 302 +/- 53.3 before the administration and 307 +/- 39.7 at 30 minutes after the administration in the right nostril. The mean NO output in the left nostril at 30 minutes after the administration was 297.7 +/- 40.75. In neither group was there any significant difference in nasal NO output between either the pre- and postlocal anesthetic application on the exposure side (Group 1, P = 0.76; group 2, P = 0.41) or the two nostrils after topical anesthesia application (group 1, P = 0.83; group 2, P = 0.62). Topical anesthesia with either lidocaine or tetracaine does not alter nasal NO output. NO measurement should not be affected in circumstances that require topical anesthesia of the nasal cavity.     

Malignant hyperthermia and the otolaryngologist

Malignant hyperthermia is a rare disorder that can occur in patients who are sensitive to certain agents used in general anesthesia. The treatment of malignant hyperthermia has not changed over the years, but prevention strategies have evolved. These strategies include an increased emphasis on how patients are managed prior to a surgical procedure, on the selection of the particular anesthetic agent, and on postoperative vigilance. Susceptible patients who undergo simple excisions or a low degree of surgical stress can receive treatment safely in the office or ambulatory surgery center and be discharged the same day, provided that all known triggering agents are avoided. For more extensive procedures that cause a moderate level of surgical stress to susceptible patients, facilities for managing malignant hyperthermia should be readily available. Susceptible patients who undergo high-stress invasive procedures should be hospitalized. Routine preoperative prophylactic drug administration, even with dantrolene, is no longer considered necessary for any susceptible patients. All local anesthetics--including lidocaine, which had been previously contraindicated--are now considered to be safe for use in patients who are susceptible to malignant hyperthermia. In this article, we review the prevention, diagnosis, and management of malignant hyperthermia. We also report our experience in anesthetizing a patient who had a history of malignant hyperthermia--a case that illustrates the uncertainty that can complicate the management of such patients.