Low Concentrations Of Local Anesthetics Research Articles

The Continued Evolution of Peripartum Anesthesiologists

(Can J Anaesth. 2022;69:283–288. doi: 10.1007/s12630-021-02159-z) The role of an obstetric anesthesiologist has evolved from providing effective and safe analgesia and anesthesia during cesarean deliveries. Obstetric anesthesiologists now help ensure effective and safe neuraxial catheters; offer low concentrations of local anesthetics for epidural analgesia to minimize instrumental vaginal deliveries and maximize parturient movement; use vasopressors to reduce the risk of parturient hypotension; and develop emergency protocols to best treat adverse outcomes such as pre-eclampsia and hemorrhage.

Epidural Analgesia as a Part of Combined Anesthesia during Abdominal Oncological Surgeries (Results of the Survey among the Russian Anesthesiologists and Resuscitators)

The objective: to analyze the contemporary specific parameters of intraoperative management of epidural analgesia (EA) in combined anesthesia in abdominal oncological surgeries in different medical organizations of Russia.Subjects and Methods. The data necessary for analysis and statistical processing were obtained by developing a formalized questionnaire (21 questions, some of which with the possibility of choosing several answers at the same time – multiple choice), published on the official website of the Association of Anesthesiologists-Resuscitators (https://association-ar.ru/). The survey lasted for 16 days (from May 23, 2022 to June 7, 2022). The survey results were collected using the Google Forms online service and processed using the Google Spreadsheets. Multiple choice responses were processed as absolute numbers and presented as a percentage of the total number of responses to a particular question.Results. The total number of respondents who took part in the survey was 217 specialists from various medical organizations, mostly from the North-Western Federal District of the Russian Federation (34.1%) with more than 15 years of expertise in the specialty (44.7%). According to the survey results, the following specific features of EA during combined anesthesia practice in Russia have been identified: most participants perform EA in the sitting position (63.6%); ropivacaine is the drug of choice among local anesthetics (LA) (84.2%); as a rule, EA is initiated prior to incision (69.6%). During open surgical interventions, 44.7% use a combined EA method (continuous infusion and bolus injection – bolus-based mode), while during laparoscopic surgeries there is no preferred method (combined method – 33.1%; continuous infusion only – 35.5%; bolus injection only – 31.4%). Low concentrations of LA (0.2 ‒ 0.375%) combined with a low volume of administration (4‒10 ml for bolus, 4‒8 ml/h for infusion) are used more often both in open and laparoscopic surgeries. In most cases, achievement of effective EA is supported by lower doses of systemic opioid analgesics (65.4%). Insufficient degree of intraoperative analgesia is managed in different ways, such as using systemic opioids (68.7%), enhancing epidural analgesia (17.5%), and administration of non-opioid analgesics (13.8%).Conclusion. At present, there is no unified approach to the method of EA in combined anesthesia. The results of the survey showed the uncertainty of experts' opinions regarding the choice of LA concentrations for EA, the rate and volume of its administration into the epidural space. Finding the optimal method of intraoperative EA in abdominal oncological surgery is the most important clinical objective in terms of reducing perioperative complications.

Epidural Oxycodone for Acute Pain.

Epidural analgesia is commonly used in labour analgesia and in postoperative pain after major surgery. It is highly effective in severe acute pain, has minimal effects on foetus and newborn, may reduce postoperative complications, and enhance patient satisfaction. In epidural analgesia, low concentrations of local anaesthetics are combined with opioids. Two opioids, morphine and sufentanil, have been approved for epidural use, but there is an interest in evaluating other opioids as well. Oxycodone is one of the most commonly used opioids in acute pain management. However, data on its use in epidural analgesia are sparse. In this narrative review, we describe the preclinical and clinical data on epidural oxycodone. Early data from the 1990s suggested that the epidural administration of oxycodone may not offer any meaningful benefits over intravenous administration, but more recent clinical data show that oxycodone has advantageous pharmacokinetics after epidural administration and that epidural administration is more efficacious than intravenous administration. Further studies are needed on the safety and efficacy of continuous epidural oxycodone administration and its use in epidural admixture.

A Systematic Review and Meta-Analysis of Randomized Controlled Trials of Labor Epidural Analgesia Using Moderately High Concentrations of Plain Local Anesthetics versus Low Concentrations of Local Anesthetics with Opioids.

PurposeCompared to low concentrations of local anesthetics with opioids for labor epidural analgesia, very high concentrations of local anesthetics are associated with an increased risk of assisted vaginal delivery. We aimed to investigate if moderately high concentrations of plain local anesthetics are also associated with this risk.MethodsWe searched for published randomized controlled trials that compared moderately high concentrations of plain local anesthetics (>0.1% but ≤0.125% bupivacaine, >0.1% but ≤0.125% levobupivacaine, or >0.17% but ≤0.2% ropivacaine) to low concentrations of local anesthetics (≤0.1% bupivacaine, ≤0.1% levobupivacaine, or ≤0.17% ropivacaine) with opioids for labor analgesia. Meta-analyses were performed to compare the risk of assisted vaginal delivery and other perinatal outcomes between these two groups.ResultsWe identified nine randomized controlled trials with a total of 1334 participants. Meta-analysis of these nine trials showed no differences in the risks of assisted vaginal delivery (odds ratio [OR] = 1.18; 95% confidence interval [CI], 0.93–1.49) or Cesarean delivery (OR = 0.96; 95% CI, 0.71–1.29) between the two groups. The incidence of motor block was higher in the group of moderately high concentrations (OR = 4.05; 95% CI, 2.19–7.48), while the incidence of pruritus was lower (OR = 0.07; 95% CI, 0.03–0.16).ConclusionThis systematic review and meta-analysis suggests that the current evidence is inadequate to support that moderately high concentrations of plain local anesthetics increase the risk of assisted vaginal delivery compared to low concentrations of local anesthetics with opioids.

A comparative study of low concentration of levobupivacaine versus ropivacaine with fentanyl for patient-controlled epidural labour analgesia

Background and Aims: Lumbar epidural analgesia is considered the modality of choice for labour analgesia. Despite its super analgesia and improved safety profile, it has been associated with maternal adverse effects like higher incidence of instrumental assisted vaginal delivery (AVD) and motor block leading to decreased ambulation. This study was designed to evaluate the efficacy of low concentrations of local anaesthetics (0.1% ropivacaine and 0.1% levobupivacaine) with 2 μg/ml fentanyl as a patient controlled epidural analgesia (PCEA) technique on the incidence of instrumental AVD along with evaluation of obstetric, maternal, and foetal outcomes. Materials and Methods: In this prospective study, 60 labouring parturients were randomly allocated into two equal groups to receive either 0.1% ropivacaine with 2 μg/ml fentanyl or 0.1% levobupivacaine with 2 μg/ml fentanyl as epidural solutions via PCEA pump infusions (4 ml/h) after 15 ml loading dose of the respective solutions. The incidence of instrumental AVD was noted as the primary outcome along with demographic data, maternal and foetal vital parameters, maternal VAS scores, degree of motor blockade and total epidural drug consumption. Results: The incidence of instrumental AVD was found to be 43.3% in the levobupivacaine group and 30% in the ropivacaine group. This difference was not statistically significant. Both the groups were comparable in terms of demographic data, maternal VAS scores, total epidural drug consumption and foetal APGAR scores. Conclusion: The use of newer local anaesthetics (levobupivacaine and ropivacaine) in low concentrations with opioids (fentanyl) as a PCEA technique may offer high maternal satisfaction in terms of quality of pain relief with fewer adverse events like instrumental AVD and adverse foetal outcomes.

Effects of Epidural Labor Analgesia With Low Concentrations of Local Anesthetics on Obstetric Outcomes: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

(Anesth Analg. 2017;124(5):1571–1580) Epidural analgesia may slightly prolong the second stage of labor and increase the instrumental birth rate, especially when high concentrations of local anesthetics are used. Consequently, low concentrations of local anesthetics (LCLAs) have become popular for epidural labor analgesia to help mediate second stage labor. The authors of the present study conducted a systematic review and meta-analysis to compare the effects of epidural analgesia with LCLAs with that of nonepidural analgesia on obstetric outcomes.

Effects of Epidural Labor Analgesia With Low Concentrations of Local Anesthetics on Obstetric Outcomes: A Systematic Review and Meta-analysis of Randomized Controlled Trials.

Low concentrations of local anesthetics (LCLAs) are increasingly popular for epidural labor analgesia. The effects of epidural analgesia with low concentrations of anesthetics on the duration of the second stage of labor and the instrumental birth rate, however, remain controversial. A systematic review was conducted to compare the effects of epidural analgesia with LCLAs with those of nonepidural analgesia on obstetric outcomes. The databases of PubMed, Embase, and the Cochrane controlled trials register were independently searched by 2 researchers, and randomized controlled trials that compared epidural labor analgesia utilizing LCLAs with nonepidural analgesia were retrieved. The primary outcomes were the duration of the second stage of labor and the instrumental birth rate; secondary outcomes included the cesarean delivery rate, the spontaneous vaginal delivery rate, and the duration of the first stage of labor. Ten studies (1809 women) were included. There was no significant difference between groups in the duration of the second stage of labor (mean difference = 5.71 minutes, 95% confidence interval [CI], -6.14 to 17.83; P = .36) or the instrumental birth rate (risk ratio [RR] = 1.52, 95% CI, 0.97-2.4; P = .07). There was no significant difference between groups in the cesarean delivery rate (RR = 0.8, 95% CI, 0.6-1.05; P = .11), the spontaneous vaginal delivery rate (RR = 0.98, 95% CI, 0.91-1.06; P = .62), or the duration of the first stage of labor (mean difference = 17.34 minutes, 95% CI, -5.89 to 40.56; P = .14). Compared with nonepidural analgesia, epidural analgesia with LCLAs is not associated with a prolonged duration of the second stage of labor or an increased instrumental birth rate. The results of this meta-analysis are based on small trials of low quality. These conclusions require confirmation by large-sample and high-quality trials in the future.

Concentración mínima efectiva de bupivacaína para el bloqueo del plexo braquial vía axilar guiado por ecografía

IntroductionThe use of ultrasound in regional anesthesia allows reducing the dosis of local anesthetic used for peripheral nerve block. The present study was performed to determine the minimum effective concentration (MEC90) of bupivacaine for axillary brachial plexus block. MethodsPatients undergoing hand surgery were recruited. To estimate the MEC90, a sequential up-down biased coin method of allocation was used. The bupivacaine dosis was 5mL for each nerve (radial, ulnar, median, and musculocutaneous). The initial concentration was 0.35%. This concentration was changed by 0.05% depending on the previous block: a blockade failure resulted in increased concentration for the next patient; in case of success, the next patient could receive or reduction (0.1 probability) or the same concentration (0.9 probability). Surgical anesthesia was defined as driving force≤2 according to the modified Bromage scale, lack of thermal sensitivity and response to pinprick. Postoperative analgesia was assessed in the recovery room with numeric pain scale and the amount of drugs used within 4h after the blockade. ResultsMEC90 was 0.241% [R2: 0.978, confidence interval: 0.20-0.34%]. No successful block patient reported pain after 4h. ConclusionThis study demonstrated that ultrasound guided axillary brachial plexus block can be performed with the use of low concentration of local anesthetics, increasing the safety of the procedure. Further studies should be conducted to assess blockade duration at low concentrations.

Minimum effective concentration of bupivacaine for axillary brachial plexus block guided by ultrasound

IntroductionThe use of ultrasound in regional anesthesia allows reducing the dose of local anesthetic used for peripheral nerve block. The present study was performed to determine the minimum effective concentration (MEC90) of bupivacaine for axillary brachial plexus block. MethodsPatients undergoing hand surgery were recruited. To estimate the MEC90, a sequential up-down biased coin method of allocation was used. The bupivacaine dose was 5mL for each nerve (radial, ulnar, median, and musculocutaneous). The initial concentration was 0.35%. This concentration was changed by 0.05% depending on the previous block; a blockade failure resulted in increased concentration for the next patient; in case of success, the next patient could receive or reduction (0.1 probability) or the same concentration (0.9 probability). Surgical anesthesia was defined as driving force ≤2 according to the modified Bromage scale, lack of thermal sensitivity and response to pinprick. Postoperative analgesia was assessed in the recovery room with numeric pain scale and the amount of drugs used within 4h after the blockade. ResultsMEC90 was 0.241% [R2: 0.978, confidence interval: 0.20–0.34%]. No patient, with successful block, reported pain after 4h. ConclusionThis study demonstrated that ultrasound guided axillary brachial plexus block can be performed with the use of low concentration of local anesthetics, increasing the safety of the procedure. Further studies should be conducted to assess blockade duration at low concentrations.

Concentração mínima efetiva de bupivacaína para o bloqueio do plexo braquial via axilar guiado por ultrassom

IntroductionThe use of ultrasound in regional anesthesia allows reducing the dose of local anesthetic used for peripheral nerve block. The present study was performed to determine the minimum effective concentration (MEC90) of bupivacaine for axillary brachial plexus block (ABPB). MethodsPatients undergoing hand surgery were recruited. To estimate the MEC90, a sequential up‐down biased coin method of allocation was used. The bupivacaine dose was 5mL for each nerve (radial, ulnar, median, and musculocutaneous). The initial concentration was 0.35%. This concentration was changed by 0.05% depending on the previous block: a blockade failure resulted in increased concentration for the next patient; in case of success, the next patient could receive or reduction (0.1 probability) or the same concentration (0.9 probability). Surgical anesthesia was defined as driving force ≤ 2 according to the modified Bromage scale, lack of thermal sensitivity and response to pinprick. Postoperative analgesia was assessed in the recovery room with numeric pain scale and the amount of drugs used within 4hours after the blockade. ResultsMEC90 was 0.241% [R2: 0.978, confidence interval: 0.20%–0.34%]. No successful block patient reported pain after 4hours. ConclusionThis study demonstrated that ultrasound guided ABPB can be performed with the use of low concentration of local anesthetics, increasing the safety of the procedure. Further studies should be conducted to assess blockade duration at low concentrations.

Influence of Body Mass Index and Epidural Anesthesia on Lung Function

I read with interest the report by Severgnini et al.1 in which they describe that the protective mechanical ventilation improves postoperative pulmonary function in patients undergoing open abdominal surgery with general anesthesia. However, we wish to raise two concerns which may undermine the clinical validity of the authors’ conclusions.First, the authors state that the exclusion criteria included patients with body mass index greater than 40 kg/m2. It means that the inclusion criteria included patients with body mass index 40 kg/m2 or less, and obese patients (mildly obese: body mass index 25–30; obese: body mass index >30) were also included in this study. Obesity is a risk factor for perioperative pulmonary complications as the pathophysiological changes induced by obesity may jeopardize respiratory function and contribute to pulmonary morbidity, such as hypoxemia, hypercapnia, and atelectasis.2 In addition, obesity is an important risk factor for perioperative impairment of spirometric measurements in patients undergoing laparotomy.3 There is a significant negative correlation between perioperative spirometric tests and obesity. The reduction in postoperative lung volumes was significantly greater in obese patients than in normal-weight patients. Also, surgery with general anesthesia may reduce lung volumes and this effect may be greater in the obese patients.4 So, we think the authors should give the information about the proportion of the obese patients in the two groups.Second, the authors state that most patients underwent epidural anesthesia at the T8 to T12 level before general anesthesia and received continuous analgesia after surgery. High thoracic perioperative epidural anesthesia was shown to decrease spirometric measurements by blocking intercostal muscle innervation.5 Even if low concentrations of local anesthetics are used, the sensory levels of epidural anesthesia extending from approximately T4 to L1 are likely to be accompanied by some degree of muscle paralysis.6 It is more likely to block the muscles of the abdominal wall (innervation T6–L1). Even a subtle decrease in abdominal muscle tone will affect dynamic parameters. To avoid the influence of the epidural anesthesia on spirometric measurements, we think it is necessary to perform a pulmonary functional test after the epidural anesthesia. Or else, the authors should give the information about the epidural anesthesia including the dose of the local anesthetics, the direction of the epidural catheter, and the plane of the epidural anesthesia.The authors declare no competing interests.

Painless delivery: Yes or no?

Contemporary obstetrics aims to achieve painless delivery, whereby the life of the mother or fetus would not be compromised. Epidural analgesia is nowadays considered to be the method of choice for the labor pain relief. The aim of this paper is to provide an overview of the basic principles and techniques of performing epidural analgesia, its specificities for women in labor, its effects on the mother and fetus, as well as the dilemmas that accompany this method. The specificities of epidural anesthesia in pregnant women, such as soft tissue edema, increased weight, changes in texture ligaments, lumbar lordosis and engorgement of epidural veins, make it more difficult to perform the epidural block in pregnancy. The most important misconception is the influence of epidural analgesia on operative or instrumental delivery rate. Low concentrations of local anesthetic in combination with small doses of opioids, together with active management of labor by an obstetrician, would lead to increased spontaneous delivery rate. Epidural analgesia is currently the most effective and the safest method of anesthesia delivery.

Case Scenario: Compartment Syndrome of the Forearm in Patient with an Infraclavicular Catheter

Case Scenario: Compartment Syndrome of the Forearm in Patient with an Infraclavicular Catheter

Preconditioning Depolarizing Ramp Currents Enhance the Effect of Sodium Channel Blockers in Primary Sensory Afferents

The conformational state of voltage-gated sodium channels is an important determinant for the efficacy of both local anesthesia and electrical neuromodulation techniques. This study investigated the role of subthreshold preconditioning ramp currents on axonal nerve excitability parameters in the presence of sodium channel blockers in myelinated A and unmyelinated C fibers. A- and C-fiber compound action potentials were recorded extracellularly in vitro in saphenous nerve from adult rats. Nerve fibers were stimulated with a supramaximal current pulse either alone or after a 300-msec conditioning polarizing ramp current (between -10% and +100% of the original threshold current) in the presence and absence of lidocaine and tetrodotoxin (TTX). A computerized threshold tracking program (QTRAC), Institute of Neurology, University College London, London, UK) was used to determine the membrane thresholds. Preconditioning ramp currents of weak strengths increased membrane excitability. Stronger preconditioning ramp currents enhanced the potency of lidocaine and TTX to increase excitability thresholds. In A and C fibers stimulated with ramp currents of 110% (A fibers) and 40% (C fibers), lidocaine (80 μM) induced a 168 ± 15% (p < 0.001) and 302 ± 23% (p < 0.001) increase in threshold, respectively (no ramp current: 135 ± 9% and 124 ± 4%, respectively). TTX (16 nM) induced an increase in threshold of 455 ± 45% (p < 0.001) and 214 ± 22% (p = 0.005), respectively (no ramp current: 205 ± 12% and 128 ± 6%, respectively). Slow preconditioning ramp stimuli inactivate sodium currents. In the presence of sodium channel blockers, stronger ramp stimuli cause an increase in threshold, which is larger than that caused by the sodium channel blocker alone. Therefore, we conclude that small depolarizing ramp currents could be used to increase excitability threshold in the presence of low concentrations of local anesthetics. These additive effects might represent a target to address with peripheral nerve stimulation in order to suppress afferent pain signaling.

Molecular Dynamics Study on the Encapsulation of Prilocaine in Liposomes at Physiological pH

In this work, we investigated the concentration effects on the encapsulation of prilocaine (PLC), an aminoamide local anesthetic, into a small unilamellar liposome, at physiological pH. On the line of our previous work, we have carried out Molecular Dynamics (MD) simulations using a coarse grain (CG) model that allow us to reach the microsecond time scale. At physiological pH there is a partition between protonated and neutral PLCs. In order to estimate the protonated/neutral PLC ratio at physiological pH (7.4), we have used the Henderson-Hasselbach equation. We have studied three PLC:lipid molar concentrations, ranging between 10:10 to 1:4. We essentially found that all neutral PLC molecules rapidly diffuse into the hydrophobic region of the vesicle adopting an asymmetric bimodal distribution. Moreover, protonated PLC molecules partition between the external monolayer of the vesicle and the water phase, having a high rate of exchange between this two phases, with no access to the inner part of the liposome in a concentration dependent way. In this way, we found that the behavior of PLCs at physiological pH is a combination of high and low pH, especially at low concentration of local anesthetics.

Apnea and unconsciousness after accidental subdural placement of an epidural catheter

Apnea and unconsciousness after accidental subdural placement of an epidural catheter

Local Anesthetis and Adjuvants in Pediatric Regional Anesthesia

The pediatric loco-regional techniques are considered very safe and effective, first of all because they target the therapy directly to the site of surgery, decreasing the risks of intravenous analgesia. The quality of local anesthesia is influenced by structural and biophysical characteristics of local anesthetics drug, dose, site of injection, mixture of local anesthetics and possible addition of a vasoconstrictor or an adjuvant to prolong the analgesic effect. In children, unlike adults, small nerve diameters and short distance between Ranvier nodes permit to use large volumes and low concentrations of local anesthetics. The clinical practice has shown that in pediatric population, effective analgesia is obtained by 1% mepivacaine, 1% lidocaine and 0.25% bupivacaine or better 0.2% ropivacaine, 0.2-0.25% levobupivacaine. In addition, levobupivacaine and ropivacaine have a better profile in terms of safety in comparison to bupivacaine and are the local anesthetics of choice for the daily clinical practice also in children as in adults. Among the adjuvant, clonidine and ketamine showed the best pharmacokinetic and pharmacodynamic profiles of effective and safety, improving and prolonging the action of associated local anesthetics. Therefore, the use of enantiomers, in association with adjuvants as clonidine or ketamine, using the multimodal approach of integrated anesthesia, makes the clinical practice effective and safe in the pediatric operating rooms. This review focuses on the overview of local anesthetics and adjuvants used today in locoregional pediatric anesthesia, with an emphasis on the advantages and disadvantages of each drug.

Further biochemical characterization of [3H]dihydroazapetine binding to alpha-adrenoceptorrelated proteins from the rat vas deferens.

Abstract The binding of [3H]dihydroazapetine, a reversible blocker of the α-adrenoceptor, has been characterized in a membrane preparation from the rat vas deferens. Binding is rapid, reversible and shows evidence of saturation. Postganglionic sympathetic denervation of the tissue does not decrease binding to the subcellular fraction. Drugs known to act on the α-adrenoceptor are specific inhibitors of [3H]dihydroazapetine binding while those acting on other receptors are without effect. Scatchard plot analysis suggests that two specific binding components are present, one of which has a similar dissociation constant for [3H]dihydro-azapetine to that determined pharmacologically. [3H]Dihydroazapetine binding is lowest in the physiological pH range and tends to decrease with increasing temperature in the range of 25 to 60°. Calcium, magnesium, sodium and potassium inhibit binding of [3H]dihydroazapetine with the divalent ions being approximately 100 times more potent. Studies with group selective reagents indicate that a disulphide bridge, and sulphydryl and carbonyl groups, are at or near the binding site and are necessary for binding. The site is protein possibly with involvement of phospholipids. Specific binding of [3H]dihydroazapetine is inhibited by low concentrations of local anaesthetics suggesting that the binding site of the antagonist may be related to the ‘calcium mobilization’ site of the α-adrenoceptor.

Activation of TRPA1 by Membrane Permeable Local Anesthetics

BackgroundLow concentrations of local anesthetics (LAs) suppress cellular excitability by inhibiting voltage-gated Na+ channels. In contrast, LAs at high concentrations can be excitatory and neurotoxic. We recently demonstrated that LA-evoked activation of sensory neurons is mediated by the capsaicin receptor TRPV1, and, to a lesser extent by the irritant receptor TRPA1. LA-induced activation and sensitization of TRPV1 involves a domain that is similar, but not identical to the vanilloid-binding domain. Additionally, activation of TRPV1 by LAs involves PLC and PI(4,5)P2-signalling. In the present study we aimed to characterize essential structural determinants for LA-evoked activation of TRPA1.ResultsRecombinant rodent and human TRPA1 were expressed in HEK293t cells and investigated by means of whole-cell patch clamp recordings. The LA lidocaine activates TRPA1 in a concentration-dependent manner. The membrane impermeable lidocaine-derivative QX-314 is inactive when applied extracellularly. Lidocaine-activated TRPA1-currents are blocked by the TRPA1-antagonist HC-030031. Lidocaine is also an inhibitor of TRPA1, an effect that is more obvious in rodent than in human TRPA1. This species-specific difference is linked to the pore region (transmembrane domain 5 and 6) as described for activation of TRPA1 by menthol. Unlike menthol-sensitivity however, lidocaine-sensitivity is not similarly determined by serine- and threonine-residues within TM5. Instead, intracellular cysteine residues known to be covalently bound by reactive TRPA1-agonists seem to mediate activation of TRPA1 by LAs.ConclusionsThe structural determinants involved in activation of TRPA1 by LAs are disparate from those involved in activation by menthol or those involved in activation of TRPV1 by LAs.

Epidural analgesia for labor: Current techniques.

Epidural analgesia is an extremely effective and popular treatment for labor pain. In this review, we trace the history of the use of epidural analgesia and its refinements. We then outline the goals of treatment and methods used to attain those goals. The use of low concentrations of local anesthetics, combined with lipid-soluble opioids, does not impede the progress of labor or depress the newborn. The incidence of side effects is low. Maintenance of analgesia that allows patient control enhances patient satisfaction.