Methaemoglobinaemia in pregnancy with chronic kidney disease an uncommon case: A case report.

The development of methaemoglobinaemia due to prilocaine, which is used for local anaesthesia, is a rare, life-threatening, but well-known side effect. The development of this side-effect in a pregnant patient with chronic kidney disease can lead to foetal distress. The case presented here is of a 21-year old pregnant female with chronic kidney disease who required haemodialysis in the 22nd week of pregnancy due to the progression to end-stage kidney disease. During haemodialysis, a right jugular tunneled double-lumen catheter was inserted using prilocaine as the local anaesthetic. Prilocaine-induced methaemoglobinaemia was diagnosed. In the 24-hour follow-up, the methaemoglobin level decreased to normal with oxygen supply of 10-15 L/min, 2 units of erythrocyte suspension and accompanying haemodialysis.

Topical anesthetics for pediatric laser treatment.

Topical anesthetic agent causes transient insensibility to pain in a limited area of skin, and provides effective anesthesia in a short onset time, short duration, with seldom local or systemic side effects on intact skin and is simple to use. Topical formulations may offer significant benefits for prevention of procedural pain. Currently, they are considered to be the most effective anesthesia for laser treatments. Unfortunately, there is no standard anesthetic technique for this procedure. Lasers are being widely used in numerous dermatological and esthetics treatments in childhood. The advancement of new knowledge in laser technology have contributed to the development of new lasers that are commonly used in a pediatric population, such as Pulsed Dye, Carbon-dioxide and Nd:YAG laser. The most commonly used topical anesthetics in young patients for minimally or moderately painful laser cutaneous procedures are Lidocaine, Prilocaine, Tetracaine gel and combinations thereof.

Transient Methemoglobinemia in three Neonates due to Maternal Pudendal Anesthesia.

Methemoglobin (MetHb) is a form of hemoglobin which contains iron in ferric state. The delivery of oxygen to tissues is impaired and cellular hypoxia develops with an increase in MetHb levels. Methemoglobinemia is a rare but potentially lethal complication of local anesthetics. In this clinical brief, three cases of transient neonatal methemoglobinemia, caused by maternal pudendal anesthesia with prilocaine, are reported.

Topic anaesthesia with a eutectic mixture of lidocaine/prilocaine cream after elective caesarean section: a randomised, placebo-controlled trial.

PURPOSE: Aim of the study was to investigate the topical application of a eutectic mixture of lidocaine/prilocaine (EMLA®) cream after caesarean section (CS) and its effect on postoperative pain, time to mobilisation, and time to discharge. MATERIALS AND METHODS: A total of 189 pregnant women were enrolled; full data sets were available for 139 of them, who were prospectively randomised to receive either placebo (control group) or EMLA® cream (study group) on the CS lesion directly as well as 24 h after surgery. Postoperative pain was assessed 24 and 48 h after surgery using the short form of the McGill Pain Questionnaire (SF-MPQ). Additional analgesic pain medication on demand was assessed in both groups. RESULTS: A total of 62 women were allocated randomly to the study and 77 patients to the control group before primary CS. There were no statistically significant differences regarding demographic and surgical parameters comparing both collectives. In addition, the postoperative total pain scores after 24 h [McGill total: 38.5 (0-102) vs. 50 (0-120) p = 0.0889] as well as after 48 h [24 (0-79) vs. 30.5 (0-92); p = 0.1455] showed no significant differences. Furthermore, time to mobilisation (hours) [9.68 (2.18-51.38) vs. 9.47 (4.18-41.77); p = 0.5919] and time to discharge (hours) [98.6 (54.08-170.15) vs. 98.2 (43.45-195.87); p = 0.5331] were comparable. CONCLUSION: The postoperative application of EMLA® cream after CS did not reduce postoperative pain or time to mobilisation or discharge, so that its use in this context has to be seen critically.

Paraesthesia after local anaesthetics: an analysis of reports to the FDA Adverse Event Reporting System.

This study was aimed to evaluate the possible alert signals of paraesthesia by local anaesthetics, focusing on those used in dentistry. A case/non-case study of spontaneous adverse events recorded in FAERS (FDA Adverse Event Reporting System) between 2004 and 2011 was performed. Cases were represented by the reports of reactions grouped under the term 'Paraesthesias and dysaesthesias' involving local anaesthetics (ATC: N01B*); non-cases were all other reports of the same drugs. Reporting odds ratios (ROR) with the relevant 95% confidence intervals (95CI) were calculated. Alert signal was considered when number of cases >3 and lower limit of ROR 95CI > 1. To estimate the specificity of signals for dentistry, the analysis was restricted to the specific term "Oral Paraesthesia" and to reports concerning dental practice. Overall, 528 reports of 'Paraesthesias and dysaesthesias' were retrieved, corresponding to 573 drug-reaction pairs (247 lidocaine, 99 bupivacaine, 85 articaine, 30 prilocaine, 112 others). The signal was significant only for articaine (ROR=18.38; 95CI = 13.95-24.21) and prilocaine (2.66; 1.82-3.90). The analysis of the specific term "Oral Paraesthesia" retrieved 82 reports corresponding to 90 drug-reaction pairs (37 articaine, 19 lidocaine, 14 prilocaine, 7 bupivacaine, 13 others) and confirmed the signal for articaine (58.77; 37.82-91.31) and prilocaine (8.73; 4.89-15.57). The analysis of reports concerning dental procedures retrieved a signal for articaine, both for any procedures (8.84; 2.79-27.97) and for non-surgical ones (15.79; 1.87-133.46). In conclusion, among local anaesthetics, only articaine and prilocaine generated a signal of paraesthesia, especially when used in dentistry.

Transient neonatal methemoglobinemia caused by maternal pudendal anesthesia in delivery with prilocaine: report of two cases.

This paper reports two cases of transient neonatal methemoglobinemia caused by maternal pudendal anesthesia with prilocaine. In the first case a two-hour-old, 3100 gram term-male infant was admitted to Neonatal Intensive Care Unit (NICU) because of central cyanosis. He was born from a 21-year-old mother with spontaneous vaginal delivery. Central cyanosis was noted without respiratory distress. Oxygen saturation was recorded as 72% with pulse oximetry in room air and with oxygen given by mask. Chest radiogram, echocardiography and laboratory findings were found to be normal except a methemoglobin level of 28%. No etiology was found, except for maternal prilocaine administration during labor. In the second case a six-hour-old 3300 gram, full-term male neonate born by spontaneous vaginal delivery was admitted to NICU for central cyanosis. The neonate was noted to have central cyanosis with respiratory distress. Oxygen saturation with pulse oximetry was 70% with mask oxygen therapy. Methemoglobin level was 42%. The neonate was treated with single dose intravenous ascorbic acid (300 mg/kg) to which he responded dramatically at 24 hours of life. No other etiology was detected except pudendal anesthesia during delivery with prilocaine. According to the authors, prilocaine administered before delivery to provide maternal local pudendal anesthesia may cause transient neonatal methemoglobinemia. All neonates born to mothers who receive potential oxidant drugs like prilocaine just before the time of delivery should be carefully monitored for methemoglobinemia.

[The surface anesthesia in outpatient pediatric department].

The combination of even parts lidocaine and prilocaine in crème substance was used for surface anesthesia in 73 children, aged 1,5-16 years. Such surgical interventions as molluscum contagiosum eradication, laser wart resection and prepuce synechia dissection were performed. The described anesthetic was highly effective in all areas, but the nasolabial triangle. Resection of warts larger then 0,5 sm required either additional infiltrative anesthesia or step-wise resection. Local allergic reaction was registered in one case, no systemic reactions were noticed. Generally, the used method of surface anesthesia proved to be highly appropriate in pediatric practice.

Trigeminal nerve injuries in relation to the local anaesthesia in mandibular injections.

OBJECTIVE: This study reports the signs and symptoms that are the features of trigeminal nerve injuries caused by local anaesthesia (LA). METHODS: Thirty-three patients with nerve injury following LA were assessed. All data were analysed using the SPSS statistical programme and Microsoft Excel. RESULTS: Lingual nerve injury (LNI; n = 16) and inferior alveolar nerve injury (IANI; n = 17) patients were studied. LNI were more likely to be permanent. Neuropathy was demonstrable in all patients with varying degrees of paraesthesia, dysaesthesia (in the form of burning pain) allodynia and hyperalgesia. All injuries were unilateral. A significantly greater proportion of LNI patients (75%) had received multiple injections, in comparison to IANI patients (41%) (p <0.05). Fifty percent of patients with LNI reported pain on injection. The presenting signs and symptoms of both LNI and IANI included pain. These symptoms of neuropathy were constant in 88% of the IANI group and in 44% of LNI patients. Functional difficulties were different between the LNI and IANI groups, a key difference being the presence of severely altered taste perception in nine patients with LA-induced LNI. CONCLUSIONS: Chronic pain is often a symptom after local anaesthetic-induced nerve injury. Patients in the study population with lingual nerve injury were significantly more likely to have received multiple injections compared to those with IANI.

Double-blind, randomized, intraindividual comparison study of the efficacy of prilocaine and lidocaine in tumescent local anesthesia.

BACKGROUND: Tumescent local anesthesia (TLA) with lidocaine or prilocaine solutions is widely used in dermatology. OBJECTIVE: Comparison of efficacy and safety of lidocaine and prilocaine in liposuctions with TLA. METHODS: TLA was performed using defined dilutions of lidocaine or prilocaine. Half-side comparisons were applied on 26 patients undergoing symmetric liposuction. Pain reduction (overall sensation and pain at lancet prick) and tolerance were assessed before, during and 2-24 h after liposuction. RESULTS: No differences in overall pain sensation between the substances were detected during and after liposuction except a more rapid onset with lidocaine (less pain after 15 min, p < 0.043). Local tolerance of both substances was excellent. CONCLUSION: Lidocaine and prilocaine used in TLA for liposuction show good efficacy and tolerance. A fixed combination of lidocaine and prilocaine may reduce the risk of side effects when great quantities of TLA are needed.

Safety of lidocaine 15% and prilocaine 5% topical ointment used as local anesthesia for intense pulsed light treatment.

BACKGROUND: Literature cautions against applying lidocaine 15%/prilocaine 5% over an area larger than 300 cm(2). The area of the face, neck, and chest is 400 cm(2) or greater. OBJECTIVE: To investigate the safety of lidocaine 15%/prilocaine 5% topical anesthetic ointment used as anesthesia for intense pulsed light (IPL) treatment. METHODS AND MATERIALS: Lidocaine 15%/prilocaine 5% ointment was applied to the face only (n=10) for 30 +/- 15 minutes or to the face, neck, and chest (n=10) for a total of 60 +/- 15 minutes before IPL. Blood lidocaine and prilocaine levels were measured. Adverse events were recorded. RESULTS: For the entire cohort, blood was drawn 25.6 +/- 6.6 minutes after IPL was completed. In the face only group, the mean lidocaine level was 0.122 +/- 0.125 microg/mL, and the mean prilocaine level was 0.048 +/- 0.029 microg/mL. In the face, neck, and chest group, the mean lidocaine level was 0.272 +/- 0.208 microg/mL, and the mean prilocaine level was 0.087 +/- 0.060 microg/mL. No adverse events related to systemic toxicity were observed or reported to the nurse. At the 24-hour follow-up, no subject reported symptoms of systemic toxicity after leaving the clinic. CONCLUSION: Under the conditions of this study, topical lidocaine 15%/prilocaine 5% produces low levels of systemic absorption.

Plain articaine or prilocaine for spinal anaesthesia in day-case knee arthroscopy: a double-blind randomized trial.

BACKGROUND: Both prilocaine and articaine are short-acting local anaesthetics suited for spinal anaesthesia for day-case knee arthroscopy. Articaine is thought to have a faster onset and shorter duration of action than prilocaine, although no comparative study has been published in the anaesthetic literature. METHODS: In this prospective randomized double-blind study, spinal anaesthesia was performed in 72 ASA I-II patients undergoing knee arthroscopy with 50 mg of either plain prilocaine or plain articaine. The primary outcome variable was duration of motor block. Secondary outcomes were onset of sensory and motor blocks, maximum spread of the sensory block, time to spontaneous voiding, and side-effects. RESULTS: Time to full motor function recovery was shorter after articaine than prilocaine [mean (SD) 140 (33) vs 184 (46) min, respectively, P<0.001]. Time to spontaneous voiding was shorter after articaine than prilocaine [mean (SD) 184 (39) vs 227 (45) min, respectively, P<0.001]. One patient in the articaine group reported mild transient neurological symptoms (TNS) limited to the first postoperative day, but there were no significant differences in adverse effects between the groups. CONCLUSIONS: Spinal anaesthesia with plain articaine 50 mg resulted in a faster recovery of motor function and earlier spontaneous voiding compared with plain prilocaine 50 mg. Surgical anaesthesia was not different. The incidence of TNS was low.

Prilocaine induced methaemoglobinaemia in a medically compromised patient. Was this an inevitable consequence of the dose administered?

Patient M, a 45-year old female, was admitted for extractions with local anaesthetic, sedation and monitoring. This was to be carried out on an in patient basis due to the patient's extensive medical history which included rheumatic heart disease, previous deep vein thrombosis and severe ulcerative colitis. Patient M also gave a history of allergy to penicillin and lignocaine. The procedure was completed without incident, local anaesthesia having been achieved using Citanest with Octapressin (prilocaine 30 mg/ml and felypressin 0.03 unit/ml 2 ml cartridge). However, on recovery Patient M's oxygen saturations dropped to 90% on air and although she had no symptoms, the levels could not be improved with supplemental oxygen. A diagnosis of methaemoglobinaemia (MetHb) was established, a rare complication associated with the administration of prilocaine. Patient M was transferred to the high dependency unit and was given methylthioninium chloride (methylene blue) intravenously. Her oxygen saturations quickly returned to normal and she was discharged the following day. This case highlights issues relating to the risk of developing MetHb, what is considered the maximum safe dose of prilocaine and some incongruities the authors feel exist in the literature.

Frequency of transient ipsilateral vocal cord paralysis in patients undergoing carotid endarterectomy under local anesthesia.

BACKGROUND: Especially because of improvements in clinical neurologic monitoring, carotid endarterectomy done under local anesthesia has become the technique of choice in several centers. Temporary ipsilateral vocal nerve palsies due to local anesthetics have been described, however. Such complications are most important in situations where there is a pre-existing contralateral paralysis. We therefore examined the effect of local anesthesia on vocal cord function to better understand its possible consequences. METHODS: This prospective study included 28 patients undergoing carotid endarterectomy under local anesthesia. Vocal cord function was evaluated before, during, and after surgery (postoperative day 1) using flexible laryngoscopy. Anesthesia was performed by injecting 20 to 40 mL of a mixture of long-acting (ropivacaine) and short-acting (prilocaine) anesthetic. RESULTS: All patients had normal vocal cord function preoperatively. Twelve patients (43%) were found to have intraoperative ipsilateral vocal cord paralysis. It resolved in all cases < or =24 hours. There were no significant differences in operating time or volume or frequency of anesthetic administration in patients with temporary vocal cord paralysis compared with those without. CONCLUSION: Local anesthesia led to temporary ipsilateral vocal cord paralysis in almost half of these patients. Because pre-existing paralysis is of a relevant frequency (up to 3%), a preoperative evaluation of vocal cord function before carotid endarterectomy under local anesthesia is recommended to avoid intraoperative bilateral paralysis. In patients with preoperative contralateral vocal cord paralysis, surgery under general anesthesia should be considered.

Transdermal diclofenac patch vs eutectic mixture of local anesthetics for venous cannulation pain.

PURPOSE: To compare the efficacy and side effects of transdermal diclofenac patch with eutectic mixture of local anesthetic (EMLA) cream in attenuating venous cannulation pain. METHODS: Adult ASA I or II patients undergoing elective surgery were randomly divided into three groups of 150 each. Group 1 (Control) patients received a placebo patch; Group 2 (EMLA) patients received EMLA cream; Group 3 (Diclofenac) patients received a transdermal diclofenac patch. The patches were applied at the proposed venous cannulation site 60 min prior to cannulation and pain resulting from an 18G cannula was assessed on an ten-point visual analogue scale (VAS). The cannulation site was observed for blanching, erythema, induration and edema for up to 24 hr. RESULTS: The incidence of venous cannulation pain was 100% in the control group, as compared to 37% and 48% of patients who experienced pain in the EMLA (P = 0.001) and diclofenac (P = 0.001) groups, respectively. The severity of venous cannulation pain [median (VAS) with interquartile ranges] was also higher in the control group: 6 (3) as compared to VAS sores of 0 (1) and 0 (2) in the EMLA (P = 0.001) and diclofenac (P = 0.001) groups. Blanching occurred with greater frequency in the EMLA group compared with the diclofenac (P = 0.001 at six hours) and placebo groups (P = 0.001 at six hours). Erythema, induration and edema were reduced in the diclofenac group compared with the EMLA (P = 0.001 for all comparisons) and placebo groups (P = 0.04 for edema at six hours and P = 0.001 for other comparisons). CONCLUSION: Transdermal diclofenac patch and EMLA are equally effective in reducing venous cannulation pain, but signs of erythema, induration and edema are less frequently observed with the transdermal diclofenac patch.

[Tumescent anaesthesia for dermatological surgery. Plasma concentrations of lidocaine and prilocaine]. / Tumeszenzlokalanästhesie bei dermatologischen Eingriffen. Plasmakonzentrationen von Lidocain und Prilocain.

BACKGROUND: Tumescent anaesthesia is currently used for several dermatological procedures. The objective of this study was to determine the plasma concentrations of local anaesthetics under real operating conditions with this anaesthetic technique. METHODS: A total of 31 patients received 3 different anaesthetic solutions with prilocaine and lidocaine for several surgical procedures. The concentrations of local anaesthetics, methemoglobin, epinephrine as well as the occurrence of adverse reactions were determined 30 min, 1 h, 3 h, 6 h, 12 h and 24 h after administration RESULTS: Maximum plasma concentrations of prilocaine were measured predominantly after 3 and 6 h, for lidocaine after 6 h. In two patients maximum plasma levels occurred 24 h after infiltration. Although toxic concentrations were not exceeded, side-effects could be observed in four patients. CONCLUSIONS: Even if the measured concentrations of local anaesthetics appeared to be safe, slight and moderate side-effects could be observed in 12.9% of cases. Maximum plasma levels of local anaesthetics may still occur 24 h after administration.