Periarticular Infiltration Compared to Single Femoral Nerve Block in Total Knee Arthroplasty: A Prospective Randomized Study.

Objective To compare patients undergoing total knee arthroplasty (TKA) under spinal anesthesia and single femoral nerve block (FNB) with subjects undergoing TKA under spinal anesthesia and periarticular infiltration (PAI). Materials and Methods A total of 100 patients undergoing primary TKA were randomized into two groups. Group 1 included patients undergoing surgery under FNB associated with spinal anesthesia, while group 2 included patients undergoing TKA under IPA and spinal anesthesia. The assessment of these subjects in the early postoperative period included pain, active flexion, active extension, elevation of the extended limb, and morphine use. Results There was no significant difference in the types of analgesia concerning pain, the elevation of the extended limb, and morphine use. Active flexion and extension were better in the PAI group ( p = 0.04 and p = 0.02 respectively). Conclusion We conclude that the techniques are similar regarding pain control, limb elevation, and morphine use. The use of IPA provided better active flexion and extension during the hospital stay compared to single FNB in patients undergoing TKA.

[Principles of the pharmacology of local anesthetics]. / Grundlagen der Pharmakologie von Lokalanästhetika.

The development of local anesthetics revolutionized the performance of painful interventions. Local anesthetics have an effect on voltage-gated sodium channels in nerve fibers and modulate the conduction of impulses. With respect to the chemical structure, local anesthetics can be divided into amide and ester types. The structural differences of local anesthetics have an influence on the duration of action, the degradation pathways and specific side effects. Severe adverse events include cardiotoxicity and neurotoxicity. In addition to basic measures, such as the monitoring and securing of vital parameters, lipid infusion represents a treatment option in cases of intoxication. The recent developments of local anesthetics are particularly concerned with the reduction of toxicity and prolonging the duration of action.

Evaluation of a modified ultrasound-assisted technique for mid-thoracic epidural placement: a prospective observational study.

BACKGROUND: Although mid-thoracic epidural analgesia benefits patients undergoing major surgery, technical difficulties often discourage its use. Improvements in technology are warranted to improve the success rate on first pass and patient comfort. The previously reported ultrasound-assisted technique using a generic needle insertion site failed to demonstrate superiority over conventional landmark techniques. A stratified needle insertion site based on sonoanatomic features may improve the technique. METHODS: Patients who presented for elective abdominal or thoracic surgery requesting thoracic epidural analgesia for postoperative pain control were included in this observational study. A modified ultrasound-assisted technique using a stratified needle insertion site based on ultrasound images was adopted. The number of needle passes, needle skin punctures, procedure time, overall success rate, and incidence of procedure complications were recorded. RESULTS: One hundred and twenty-eight subjects were included. The first-pass success and overall success rates were 75% (96/128) and 98% (126/128), respectively. In 95% (122/128) of patients, only one needle skin puncture was needed to access the epidural space. The median [IQR] time needed from needle insertion to access the epidural space was 59 [47-122] seconds. No complications were observed during the procedure. CONCLUSIONS: This modified ultrasound-assisted mid-thoracic epidural technique has the potential to improve success rates and reduce the needling time. The data shown in our study may be a feasible basis for a prospective study comparing our ultrasound-assisted epidural placements to conventional landmark-based techniques.

Modified thoracoabdominal nerves block through perichondrial approach for laparoscopic cholecystectomy

SUMMARY OBJECTIVE: A new block, namely, modified thoracoabdominal nerves block through perichondrial approach, is administered below the costal cartilage. We sought to compare the analgesic efficacy of the modified thoracoabdominal nerves block through perichondrial approach block with local anesthetic infiltration at the port sites in an adult population who underwent laparoscopic cholecystectomy. METHODS: Patients who will undergo laparoscopic cholecystectomy were randomized to receive bilateral ultrasound-guided modified thoracoabdominal nerves block through perichondrial approach blocks or local anesthetic infiltration at the port insertion sites. The primary outcome was the total amount of tramadol used in the first 12 h postoperatively. The secondary outcomes were total IV tramadol consumption for the first postoperative 24 h and visual analog scale scores. RESULTS: The modified thoracoabdominal nerves block through perichondrial approach group had significantly less tramadol use in the first 12 h postoperatively (p<0.001). The modified thoracoabdominal nerves block through perichondrial approach group's visual analog scale scores at rest (static) and with movement (dynamic) were significantly lower compared with the port infiltration group (p<0.05). CONCLUSION: Patients who received modified thoracoabdominal nerves block through perichondrial approach block had significantly less analgesic consumption and better pain scores than those who received port-site injections after laparoscopic cholecystectomy.

Perineural low dexamethasone dose as adjuvant in supraclavicular brachial plexus block for arteriovenous fistula creation in end stage renal disease: a randomized controlled trial

Abstract Background and aims: Dexamethasone as adjunct to local anesthetic solution improves the quality of brachial plexus block (BPB). However, evidence for its efficacy at low doses (< 4 mg) is lacking. This study was designed to evaluate the duration of analgesia attained with low dose dexamethasone as adjuvant to local anesthetic for creation of arteriovenous fistula (AVF) under BPB. Methods: Sixty-six patients scheduled for AVF creation were randomly allocated to receive either saline (control) or 2 mg dexamethasone, together with 0.5% ropivacaine and 0.2% lignocaine. The primary outcome was duration of analgesia, defined as time from performing the block to the first analgesic request. The secondary outcomes were time from injection to complete sensory block, time from injection to complete motor block, duration of motor block, postoperative analgesic consumption, and fistula patency at three months. Results: All the blocks were effective. In the group that received dexamethasone, the time to first analgesic request was significantly delayed (432 ± 43.8 minutes vs. 386.4 ± 40.2 minutes; p < 0.01). The onset of sensory and motor blockade occurred faster in dexamethasone group and overall analgesic consumption was also reduced. However, dexamethasone addition did not prolong the duration of motor block. There was no statistically significant difference in the patency of fistulas between the two groups at three months. (p = 0.34). Conclusion: Addition of low-dose perineural dexamethasone to local anesthetic solution significantly prolonged the duration of analgesia. Further trials are warranted to compare the adverse effects between dexamethasone doses of 4 mg and lower.

Systemic Ropivacaine Concentrations Following Local Infiltration Analgesia and Femoral Nerve Block in Older Patients Undergoing Total Knee Arthroplasty.

Purpose: The study examined the pharmacokinetic profile of fixed formulation mixtures comprising 225 mg of ropivacaine for local infiltration analgesia with or without epinephrine, and femoral nerve block in older patients presenting for orthopedic surgery and explored potential influences of block type, age, and body weight on this profile. Patients and Methods: Twenty four patients scheduled for total knee arthroplasty were randomly assigned to three groups: femoral nerve block, local infiltration analgesia with epinephrine and local infiltration analgesia without epinephrine. Blood samples were collected at 10, 30, 60, and 120 min following the block and total plasma concentrations of ropivacaine were quantified by high performance liquid chromatography. Results: The mean individual peak total plasma concentrations of ropivacaine in local infiltration analgesia with and without epinephrine, and femoral nerve block group were 0.334, 0.490 and 0.545 µg mL-1 (p = 0.16). Local infiltration with epinephrine group had significantly lower plasma ropivacaine concentrations at 30, 60 and 120 minutes. The plasma ropivacaine concentrations exceeded 2.2 µg mL-1 in one patient. Age, but not body weight, had a moderate correlation with peak plasma ropivacaine concentration (r = 0.37, p = 0.08). Conclusion: Administration of a fixed 225 mg dose of ropivacaine for local infiltration analgesia with epinephrine and femoral nerve block results in plasma ropivacaine concentrations below the toxicity threshold, indicating their safety. The use of local infiltration analgesia with epinephrine provides a greater safety margin, as local infiltration analgesia without epinephrine may lead to ropivacaine concentrations associated with symptoms of local anesthetic toxicity.

[Principles of the pharmacology of local anesthetics]. / Grundlagen der Pharmakologie von Lokalanästhetika.

The development of local anesthetics revolutionized the performance of painful interventions. Local anesthetics have an effect on voltage-gated sodium channels in nerve fibers and modulate the conduction of impulses. With respect to the chemical structure, local anesthetics can be divided into amide and ester types. The structural differences of local anesthetics have an influence on the duration of action, the degradation pathways and specific side effects. Severe adverse events include cardiotoxicity and neurotoxicity. In addition to basic measures, such as the monitoring and securing of vital parameters, lipid infusion represents a treatment option in cases of intoxication. The recent developments of local anesthetics are particularly concerned with the reduction of toxicity and prolonging the duration of action.

Current status of the combined spinal-epidural technique in obstetrics and surgery.

Epidural and spinal blocks are well-accepted neuraxial techniques but both have several disadvantages. Combined spinal-epidural (CSE) can combine the best features of both techniques and reduce or eliminate these disadvantages. It provides the rapidity, density, and reliability of subarachnoid block with the flexibility of catheter epidural technique to extend the duration of anesthesia/analgesia (and to improve spinal block). It is an excellent technique for determining minimum intrathecal drug doses. Although most commonly employed in obstetric practice, CSE is also used in a wide variety of non-obstetric surgical procedures including orthopedic, vascular, gynecological, urological, and general surgical procedures. The needle-through-needle technique remains the most commonly used method to perform CSE. Several technical variations including Sequential CSE and Epidural Volume Extention (EVE) are commonly used particularly in obstetric and high-risk patients such as those with cardiac disease where a slower onset of sympathetic block is desirable. The risks of complications such as epidural catheter migration through the dural hole, neurological complications, and subarachnoid spread of epidurally administered drugs are possible but have not been a clinically relevant problem in the 40+ years of their existence. In obstetrics, CSE is used for labor pain because it produces rapid-onset analgesia with reduced local anesthetic consumption and less motor block. The epidural catheter placed as part of a CSE is more reliable than a catheter placed as part of a conventional epidural. Less breakthrough pain throughout labor is noted and fewer catheters require replacing. Side effects of CSE include greater potential for hypotension and more fetal heart rate abnormalities. CSE is also used for cesarean delivery. The main purpose is to decrease the spinal dose so that spinal-induced hypotension can be reduced. However, reducing the spinal dose requires an epidural catheter to avoid intra-operative pain when surgery is prolonged.

Perineural low dexamethasone dose as adjuvant in supraclavicular brachial plexus block for arteriovenous fistula creation in end stage renal disease: a randomized controlled trial.

BACKGROUND AND AIMS: Dexamethasone as adjunct to local anesthetic solution improves the quality of brachial plexus block (BPB). However, evidence for its efficacy at low doses (< 4 mg) is lacking. This study was designed to evaluate the duration of analgesia attained with low dose dexamethasone as adjuvant to local anesthetic for creation of arteriovenous fistula (AVF) under BPB. METHODS: Sixty-six patients scheduled for AVF creation were randomly allocated to receive either saline (control) or 2 mg dexamethasone, together with 0.5% ropivacaine and 0.2% lignocaine. The primary outcome was duration of analgesia, defined as time from performing the block to the first analgesic request. The secondary outcomes were time from injection to complete sensory block, time from injection to complete motor block, duration of motor block, postoperative analgesic consumption, and fistula patency at three months. RESULTS: All the blocks were effective. In the group that received dexamethasone, the time to first analgesic request was significantly delayed (432 ± 43.8 minutes vs. 386.4 ± 40.2 minutes; p < 0.01). The onset of sensory and motor blockade occurred faster in dexamethasone group and overall analgesic consumption was also reduced. However, dexamethasone addition did not prolong the duration of motor block. There was no statistically significant difference in the patency of fistulas between the two groups at three months. (p = 0.34). CONCLUSION: Addition of low-dose perineural dexamethasone to local anesthetic solution significantly prolonged the duration of analgesia. Further trials are warranted to compare the adverse effects between dexamethasone doses of 4 mg and lower.

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

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

Effects of dyclonine hydrochloride mucilage on gag reflex in patients with chronic pharyngitis undergoing gastroscopy / 中国基层医药

Objective:To investigate the effects of dyclonine hydrochloride mucilage administered for oropharyngeal anesthesia on gag reflex in patients with chronic pharyngitis during gastroscopy.Methods:A total of 100 patients with chronic pharyngitis who met American Society of Anesthesiologists Classification I-II and received treatment in The First Affiliated Hospital of Ximen University from January to December 2020 were included in this study. Using the principle of voluntariness, these patients were divided into dyclonine hydrochloride mucilage (D) and control (C) groups, with 50 patients in each group. Ten minutes before anesthesia induction, patients in Group D took 10 mL of dyclonine hydrochloride mucilage in the mouth, but did not swallow it, and those in Group C were identically given equal volume of placebo. Ten minutes later, dyclonine hydrochloride mucilage or placebo was swallowed. For anesthesia induction, 20 μg Fentanyl and 2-4 mg/kg Propofol were intravenously administered. A gastroscopy examination was performed after the patient's consciousness disappeared. The patient's cough and body movement response scores during gastroscopy were recorded. Before anesthesia induction (T0), before endoscope insertion (T1), after endoscope insertion (T2), and after endoscope withdrawal (T3), mean arterial pressure and heart rate were recorded.Results:The incidence rate of cough and body movement in Group D were 20% (10/50) and 24% (12/50), which were significantly lower than 72% (36/50) and 68% (34/50) in Group C ( χ2 = 27.21, 19.49, both P < 0.001). At T1, mean arterial pressure in Group D and Group C was (62.21 ± 10.32) mmHg and (63.82 ± 10.51) mmHg(1 mmHg=0.133 kPa), respectively, which were significantly lower than (70.21 ± 13.13) mmHg and (70.91 ± 14.02) mmHg at T0 ( t = 3.15, 5.82, both P < 0.05). At T2, mean arterial pressure and heart rate in Group C were (80.13 ± 11.92) mmHg and (90.02 ± 15.63) beats/minute, respectively, which were significantly higher than (70.91 ± 14.02) mmHg and (78.75 ± 14.93) beats/minute at T0 in the same group ( t = 5.99, 4.03, both P < 0.05) and were also significantly higher than (66.21 ± 12.33) mmHg and (76.53 ± 10.31) beats/minute] at T2 in Group D ( t = 2.07, 2.67, both P < 0.05). Conclusion:Dyclonine hydrochloride mucilage administered for oropharyngeal anesthesia can effectively suppress gag reflex in patients with chronic pharyngitis and increase hemodynamic stability during gastroscopy.

Continuous Thoracic Paravertebral Block to Treat Electrical Storm.

Continuous ganglion block is increasingly being used to help manage ventricular tachyarrhythmias. We present the cases of 2 patients in whom we used continuous left thoracic paravertebral block to achieve sympathetic denervation and improvement in drug-refractory ventricular tachyarrhythmias. Whether as destination therapy or bridging therapy, we conclude that the block is safe, improves patients' comfort, and is superior in several ways to stellate ganglion block and other single-injection techniques.

Magnesium-Based Trigger Point Infiltrations Versus Local Anaesthetic Infiltrations in Chronic Pelvic Myofascial Pain: A Randomized, Double-Blind, Controlled Study.

OBJECTIVE: To determine if a novel, magnesium-based trigger point infiltration formulation is more effective in treating chronic myofascial pelvic pain than lidocaine-only infiltration. METHODS: This was a single-centre, double-blind, randomized controlled trial of women diagnosed with chronic pelvic myofascial pain associated with trigger points. We compared a novel magnesium-based infiltration formulation with lidocaine infiltration of trigger points and with a control group of participants who were waitlisted for a chronic pain clinic. Treatment groups completed a 12-week program that included 8 trigger point injection treatments and 9 visits during which pain scores were recorded and questionnaires administered. The primary outcome measure was change in mean pain score between baseline and the final visit. Secondary outcomes included pain with function scores, scores on the World Health Organization Quality of Life questionnaire, procedural pain, concomitant medication use, and complications. RESULTS: We assigned 44 women diagnosed with chronic myofascial pelvic pain associated with trigger points to either the magnesium-based infiltrate (n = 15), lidocaine infiltrate (n = 17), or waitlist (n = 12) group. In the intent-to-treat analysis, a clinically relevant decrease in mean pain score out of 10 was observed in the magnesium-based (-2.6 ± 3.2) and lidocaine (-2.9 ± 3.1) infiltration groups, but not in the waitlist group (-0.5 ± 2.3). The per protocol analysis post-hoc tests, adjusted for multiple comparisons, found a significant difference in the average change in pain score between the magnesium-based infiltrate and the waitlist groups (P = 0.045), while differences between the lidocaine infiltrate and waitlist groups approached statistical significance (P = 0.052). Both treatment groups saw improvements in pain with function and quality of life scores. CONCLUSION: While this study is underpowered, it does not support the use of a magnesium-based trigger point infiltrate in the treatment of chronic myofascial pelvic pain over lidocaine-only infiltration. Nonetheless, these results are consistent with current management recommendations and suggest improvements in pain, pain with function, and quality of life scores with either magnesium-based or lidocaine-only infiltration. We outline an approach to assessment and treatment that can be adopted by general gynaecologists.

The Diagnostic Role of Neurophysiological Tests for Premature Ejaculation: A Prospective Multicenter Study.

PURPOSE: Premature ejaculation (PE) is one of the most common male sexual dysfunctions. Local anesthetics (LAs) and dapoxetine are frequently used to treat PE; however, previous studies show variable efficacy. This study aims to determine the efficacy of LAs and dapoxetine using a novel classification based on neurophysiological tests. MATERIALS AND METHODS: This multicenter cohort study enrolled adult men (568) with an intravaginal ejaculatory latency time (IELT) ≤2 minutes. Patients were divided into 4 groups according to the results of neurophysiological tests and assigned different treatments for 12 weeks: 1) penile sensory hyperexcitability type (Sens)-LAs; 2) penile sympathetic hyperexcitability type (Symp)-dapoxetine; 3) mixed type (Mixed)-both LAs and dapoxetine; 4) normal type (Norm)-both LAs and dapoxetine. Self-estimated IELT and patient-reported outcomes were recorded. RESULTS: The total percentage of men achieving IELT >2 minutes and ≥5 minutes after treatment were 82.7% and 76.7%, respectively. For men with abnormal results of neurophysiological tests, 401 (86.6%) had improved IELT >2 minutes after the 12-week treatment course, in which 375 (81.0%) achieved IELT ≥5 minutes. All patient-reported outcome measures improved in each group after 12 weeks of treatment, with greater improvements among those with abnormal neurophysiological tests. CONCLUSIONS: The efficacy of LAs and dapoxetine increased in PE patients with abnormal results of neurophysiological tests. This novel classification of PE using neurophysiological tests could help guide and improve efficacy of PE therapies.

Effects of ultrasound-guided nerve block combined with dexmedetomidine on postoperative oxidative stress in patients with hip fracture and diabetes / 中国医师进修杂志

Objective:To explore the effect of ultrasound-guided nerve block combined with dexmedetomidine (DEX) on postoperative oxidative stress in patients with hip fracture and diabetes.Methods:From March 2017 to December 2019, 78 patients with diabetes who underwent hip fracture surgery were enrolled and divided into two groups by random number table method, with 39 cases in each group. After the operation, the control group was treated with ultrasound-guided femoral nerve combined with lateral femoral cutaneous nerve block with 0.375% ropivacaine, and the study group was treated with ultrasound-guided femoral nerve combined with lateral femoral cutaneous nerve block with 0.375% ropivacaine and DEX 0.5 μg/kg. Patients in both groups were received patient controlling intravenous analgesia (PCIA) after the operation, and visual analogue scoring (VAS) was used to evaluate the resting pain score of the patients at 4 h (T 1), 8 h (T 2), 16 h (T 3), 24 h (T 4), 36 h (T 5) and 48 h after operation (T 6). The levels of serum superoxide dismutase (SOD), malondialdehyde (MDA), 8-hydroxydeoxyuridine (8-OHdG), at T 1 and T 6 were compared between the two groups. The management system of continuous glucose monitoring system (CGMS) was used to calculate the mean amplitude of glycemic excursions(MAGE), largest amplitude of glycemic excursions (LAGE), absolute means of daily differences (MODD) of the patients during 48 h after operation, and the correlation between the blood glucose fluctuation indicators and the oxidative stress of the study group were compared. Results:The scores of VAS in the study group at T 1-T 6 were lower than those in the control group , the difference were statistically significant ( P<0.05). At T 6, the level of serum SOD in the study group was higher than that in the control group: (79.58 ± 13.55) kU/L vs. (64.16 ± 11.95) kU/L; the level of serum MDA and 8-OhdG in the study group were higher than those in the control group: (4.36 ± 0.81) μmol/L vs. (5.64 ± 0.94) μmol/L, (1.06 ± 0.19) μg/L vs.(1.42 ± 0.22) μg/L, the differences were statistically significant ( P<0.05). The levels of MAGE, LAGE, MODD in the study group were lower than those in the control group: (2.42 ± 0.47) mmol/L vs. (5.19 ± 0.96) mmol/L, (3.47 ± 0.64) mmol/L vs. (7.61 ± 1.32) mmol/L, (1.21 ± 0.27) mmol/L vs. (2.74 ± 0.46) mmol/L, the differences were statistically significant ( P<0.05). The correlation analysis showed that the blood glucose fluctuation indicators MAGE, LAGE and MODD of the study group were negatively correlated with SOD, and were positively correlated with MDA, 8-OHdG ( P<0.05). Conclusions:The use of ultrasound-guided nerve block combined with dexmedetomidine (DEX) for patients with hip fracture and diabetes can improve the analgesic effect, reduce oxidative stress of the patients, and improve the blood glucose fluctuation indicators.

Analgesic effects of ultrasound-guided rectus sheath block in open gastrectomy / 中国基层医药

Objective:To investigate the analgesic effects of ultrasound-guided rectus abdominis sheath block (RSB) in open gastrectomy.Methods:Forty-one patients with gastric cancer who underwent open gastrectomy in Binzhou Hospital of Traditional Chinese Medicine from December 2019 to December 2020 were included in this study. They were randomly assigned to undergo either RSB with 40 mL of 0.375% ropivacaine (group A, n = 21) or RSB with 40 mL of 0.9% sodium chloride injection (group B, n = 20) based on total intravenous anesthesia. After skin sutures, patient-controlled analgesia (PCA) was performed. Intraoperative dose of remifentanil and postoperative dose of PCA drug were compared between the two groups. Results:Intraoperative dose of remifentanil was significantly lower in the group A than that in the group B [(1 021.4 ± 172.0) μg vs. (1 415.0 ± 330.6) μg, t = -4.04, P = 0.001]. Postoperative doses of PCA drug used by 1 and 2 hours after surgery were (1.14 ± 0.90) mL and (0.85 ± 0.70) mL respectively in group A, which were significantly lower than (1.85 ± 0.70) mL and (1.45 ± 1.00) mL in the group B ( t = -5.96, -2.75, P < 0.001, P = 0.009). There were no significant differences in postoperative doses of PCA drug used by 3, 6, 12, 24, 48 and 72 hours after surgery between the two groups (both P > 0.05). Conclusion:RSB with 40 mL of ropivacaine applied to both sides of the incision before open gastrectomy can reduce the dose of remifentanil used during surgery and the dose of PCA drug used within 2 hours after surgery.

Complicaciones asociadas a la anestesia bucal: diagnóstico y manejo / Complications associated with oral anesthesia: diagnosis and management

La seguridad en el uso de los anestésicos locales y de los diferentes abordajes anestésicos en odontología, hacen que la práctica de la anestesia dental sea considerada segura. Los autores reportan las diferentes complicaciones inherentes al uso de la anestesia dental y las consideradas sistémicas, describiendo en cada una de ellas sus características, signos, síntomas y estrategias para solventarlas. (AU)

The safety in the use of local anesthetics and the different anesthetic approaches in dentistry make the practice of dental anesthesia considered safe. The authors report the different complications inherent to the use of dental anesthesia and those considered systemic, describing in each of them their characteristics, signs, symptoms and strategies to solve them. (AU)

Use of lidocaine with phenylephrine (Co-phenylcaine) spray for anaesthesia of the external auditory canal.

OBJECTIVE: A method is described for topical local anaesthesia of the tympanic membrane and ear canal using lidocaine and phenylephrine (Co-phenylcaine) spray and soaked micropatties. DISCUSSION: The advantages of this method are discussed in comparison to existing methods.