Local anesthetic resistance in a pregnant patient with lumbosacral plexopathy

Suspected local anesthetic resistance after intrathecal, perineural, intraarticular and subcutaneous injections: a case report

Background

Local anesthetic (LA) resistance is an exceedingly rare phenomenon. Incidence is unknown given the rarity of disease. Often, inadequate response to LA can be attributed to many factors including suboptimal dosing, maldistribution, or poor procedural technique. However, in the absence of these technical factors, true LA resistance can be attributed to mutations in the voltage gated sodium channel and is strongly associated with hypermobility conditions such as Ehlers Danlos and muscular dystrophies such as Emery-Dreifuss. There have also been reports describing LA resistance after scorpion bites, although the underlying mechanism for this type of resistance is unknown. We aim to present a case of suspected LA resistance in the setting of multiple failed LA delivery.

Case Description

In this case report, we describe a patient with suspected LA resistance after failed intrathecal, perineural, intraarticular and subcutaneous delivery of LA. Our patient was unresponsive to three different LAs at varying doses.

Conclusions

Patients with failure to achieve adequate anesthesia with more than one route of LA administration should be evaluated for LA resistance. A thorough medical history and physical examination, along with a focus on identifying prior LA failure such as with dental procedures, and physical examination findings suggestive of connective tissue disorders may help establish the diagnosis with confirmatory genetic testing.

Resistance to local anesthetics: Truth or myth?

The report of anesthetic technique failure is crucial and the etiology of the problem should be determined. We describe a case of locoregional anesthesia failure, in which, after excluding its most common causes, the resistance to local anesthetics was considered as the most probable clinical hypothesis. For this reason, a genetic test was performed, as well as the efficacy of other local anesthetics was evaluated, constituting a different approach in the cases of locoregional anesthesia failure. True resistance to local anesthetics is difficult to diagnose so information about this is scarce in the literature. One of the proposed causes is a mutation of sodium channels where local anesthetics bind. If not recognized, the application of locorregional anesthesia in this patient's condition can lead to unpleasant experiences and unnecessary risks, related to toxic levels of local anesthetics. For this reason, the resistance to local anesthetics should be always precluded in cases of strong clinical suspicion. This approach could be applied in similar cases.

Anesthesia for inguinal hernia repair: Experience with a tertiary hospital-based surgical outreach in a developing world

Background

The dearth of adequate facilities and anesthetists limits the number and extent of surgical cases that can be attended to in surgical outreach programs. Inguinal hernia remains a common health burden in the developing world. Tertiary hospitals provide good anesthetic complements to safe surgeries and will be a veritable tool in surgical outreaches.

Objectives

The objective of the study is to assess the types/techniques of anesthesia used in uncomplicated open inguinal hernia repair in a tertiary hospital-based surgical outreach program.

Materials and Methods

This study was a prospective analysis of anesthetic techniques used in all uncomplicated inguinal hernia repairs performed in outreach program over 1 week in May 2018. Data were collected with a pro forma, analyzed with SPSS, and presented in tables and figures.

Results

One hundred and ninety-five patients with uncomplicated inguinal hernias were recruited for the study. The patients' age ranged from 0 to 89 years, with a mean age of 33.62 ± 22.75 years. Most cases occurred in children. The male-to-female ratio was 7:1, and the majority were primary hernia repairs. Eighty-seven (44.6%) patients had local anesthesia (LA), 65 (33.3%) had general anesthesia (GA), while 43 (22.1%) had spinal anesthesia (SA). One hundred and sixty-two (83.1%) patients needed intraoperative analgesic augmentation. One hundred and sixty-nine (86.7%) patients were operated as day-case surgeries, while 26 (13.3%) patients were discharged the day after surgery. The failure rate of LA and SA put together was 74.6%, but there was no conversion to GA. Anesthetic complication was observed in 3.4% of cases.

Conclusion

Organizing inguinal hernia repair outreach in a tertiary hospital offers the benefit of a full complement of anesthesia, which ensures safe and smooth surgery with low anesthetic complications. Most cases were done as daycare surgeries despite the high failure rate of LA and SA.

Résumé

Contexte

Le manque d'installations adéquates et d'anesthésistes limite le nombre et l'étendue des cas chirurgicaux qui peuvent être traités dans les programmes de proximité chirurgicale. La hernie inguinale reste un fardeau de santé courant dans les pays en développement. Les hôpitaux tertiaires fournissent de bons compléments anesthésiques aux chirurgies sûres et seront un véritable outil dans les interventions chirurgicales.

Objectifs

Évaluer les types / techniques d'anesthésie utilisés dans la réparation de hernie inguinale ouverte non compliquée dans un programme de proximité chirurgicale en milieu hospitalier tertiaire.

Méthode

Une analyse prospective des techniques d'anesthésie utilisées dans toutes les réparations de hernie inguinale non compliquées effectuées dans le cadre d'un programme de sensibilisation sur une semaine en mai 2018. Les données ont été recueillies à l'aide d'un formulaire, analysées avec SPSS et présentées sous forme de tableaux et de figures.

Résultats

Cent quatre-vingt-quinze patients atteints de hernies inguinales non compliquées ont été recrutés pour l'étude. L'âge des patients variait de 0 à 89 ans avec un âge moyen de 33,62 + 22,75 ans. La plupart des cas sont survenus chez des enfants. Le ratio homme / femme était de 7: 1 et la majorité était des réparations primaires de hernie. Quatre-vingt-sept (44,6%) des patients ont eu une anesthésie locale (LA), 65 (33,3%) une anesthésie générale (AG), tandis que 43 (22,1%) une anesthésie rachidienne (SA). Cent soixante-deux (83,1%) patients ont eu besoin d'une augmentation analgésique peropératoire. Cent soixante-neuf (86,7%) patients ont été opérés en garderie tandis que 26 (13,3%) patients ont obtenu leur congé le lendemain de la chirurgie. Le taux d'échec de LA et SA réunis était de 74,6%, mais il n'y a pas eu de conversion en GA. Une complication anesthésique a été observée dans 3,4% des cas.

Conclusion

l'organisation de soins de proximité pour la réparation de la hernie inguinale dans un hôpital tertiaire offre l'avantage d'un complément complet d'anesthésie qui garantit une chirurgie sûre et en douceur avec de faibles complications anesthésiques. La plupart des cas ont été pratiqués en garderie malgré le taux d'échec élevé de l'anesthésie locale et rachidienne.

Mots-clés

Réparation de hernie inguinale, chirurgie de jour, anesthésie générale, anesthésie locale, anesthésie rachidienne.

Local anesthetic resistance in a Crohn's patient undergoing cesarean delivery

INTRODUCTION

Patient resistance to local anesthetics is rarely considered as the cause of regional anesthesia failure.

CASE REPORT

We report a case of resistance to local anesthetics in a patient with Crohn's disease who underwent cesarean section under continuous spinal anesthesia.

DISCUSSION

Resistance to local anesthetics may be more common than we think, especially among patients with chronic pain. Providers should consider local anesthetic resistance when regional anesthesia is unsuccessful. Further research is needed to determine if skin wheal tests and/or a different local anesthetic could improve results.

Approach to failed spinal anaesthesia for caesarean section

Failure of spinal anaesthesia for caesarean section may have deleterious consequences for the mother as well as the newborn baby. In this article, we discuss the mechanisms of failure of spinal anaesthesia as well as the approach to a failed block. We performed a literature search in Google Scholar, PubMed, and Cochrane databases for original and review articles concerning failed spinal anaesthesia and caesarean section. Strategies for a failed spinal anaesthetic include manoeuvers to salvage the block, repeating the block, epidural anaesthesia or a combined spinal-epidural (CSE) technique, or resorting to general anaesthesia. Factors influencing the choice of these alternative options are discussed. A "failed spinal algorithm" can guide the anaesthesiologist and help reduce morbidity and mortality.

Evaluation of failed and high blocks associated with spinal anesthesia for Cesarean delivery following inadequate labour epidural: a retrospective cohort study

PURPOSE

The purpose of this retrospective cohort study was to investigate factors associated with failed and high spinal blocks in patients who received spinal anesthesia for Cesarean delivery following a labour epidural that was inadequate for surgical anesthesia.

METHODS

We searched our perioperative database for women with a labour epidural who received spinal or combined spinal-epidural anesthesia for Cesarean delivery due to the inadequacy of the existing epidural. The primary outcome was the occurrence of failed spinal blocks, and the secondary outcome was the occurrence of high blocks following spinal administration.

RESULTS

Of the 263 patients in the analysis, there were 29 (11%) failed spinals and nine (3%) high spinals. There was a significant difference between patients with failed spinals and those with successful spinals with regards to receipt of an epidural top-up dose for Cesarean delivery within 30 min of the spinal, type of neuraxial block, body mass index, age, and dose of hyperbaric bupivacaine. In a multivariable analysis, only receipt of an epidural top-up dose was associated with failure (OR, 6.0; 95% CI, 2.1 to 17.0; P < 0.001). As for the risk of a high spinal, patient characteristics and block details were not different amongst patients, except for a younger age in those with a high block.

CONCLUSIONS

Administration of spinal anesthesia within 30 min of an epidural top-up dose is associated with increased risk of failure. We speculate that this may be due in part to the presence of a large volume of local anesthetic in the epidural space, which may be mistaken for cerebrospinal fluid during spinal placement.

Effect of previous scorpion bite(s) on the action of intrathecal bupivacaine: A case control study

Background:

During the routine practice in the institution, it was observed that there were persistent incidents of inadequate/failed spinal anaesthesia in patients with a history of single or multiple scorpion bite/s. To test any possible correlation between scorpion bite and the altered response to spinal anaesthesia, a case control study was conducted involving patients with a history of scorpion bite/s and without such a history.

Methods:

Randomly selected 70 (n=70) patients of either sex and age range of 18-80 years, were divided into two equal groups, giving past history of one or multiple scorpion bites and giving no such a history. The anaesthetic management was identical inclusive of subarachnoid block with 3.5 ml. 0.5% bupivacaine heavy. The onsets of sensory, motor and peaks of sensory and motor blocks were observed with the pin-prick method and Bromage scale. After waiting for 20 min, if the block was inadequate, then balanced general anaesthesia was administered. The analysis of the data and application of various statistical tests was carried out using Chi-square test, percentages, independent sample t-test and paired t-test.

Results:

Demographically both groups were comparable. In scorpion bite group, the time of onsets of both sensory and motor blocks and time for the peak of sensory and motor blocks were significantly prolonged, 4 patients had failed/inadequate sensory block and 5 patients had failed/inadequate motor block while all the patients in non-bite group had adequate intra-operative block.

Conclusion:

We conclude that there appears to be a direct correlation between the histories of old, single or multiple scorpion bites and development of resistance to effect of local anaesthetics administered intra-thecally.

Does scorpion bite lead to development of resistance to the effect of local anaesthetics?

A patient posted for vaginal hysterectomy was administered subarachnoid block, which failed, so was repeated in one space above. The block failed again, after waiting for 30 min. Patient gave a history of scorpion bite twice, once at the age of 17 years on her right foot and again about 8 months back. Thereafter, balanced general anaesthesia was given. On eighth post-operative day, after explaining about her possible special condition (?Resistance to local anaesthetic agents), the patient was given left median, ulnar and radial nerve blocks at the wrist and local infiltration near the anatomical snuff box. There was neither sensory nor motor block. The scorpion venom is known to affect the pumping mechanism of sodium channels in the nerve fibres, which are involved in the mechanism of action of local anaesthetic drugs, it may be responsible for the development of 'resistance' to the action of local anaesthetic agents.

Bupivacaine concentrations in the lumbar cerebrospinal fluid of patients during spinal anaesthesia

BACKGROUND

Data on bupivacaine concentrations in the cerebral spinal fluid (CSF) during spinal anaesthesia are scarce. The purpose of this study was to determine the concentration of bupivacaine in the lumbar CSF of patients with an adequate level of spinal anaesthesia after injection of plain bupivacaine 0.5%.

METHODS

Sixty patients with an adequate level of spinal block after standardized administration of plain bupivacaine 20 mg in men and of 17.5 mg in women were studied. To measure the CSF bupivacaine concentration, we performed a second lumbar spinal puncture and obtained a CSF sample at a randomized time point 5-45 min after the bupivacaine injection. In addition, we calculated the half-life of bupivacaine in the CSF and tested the hypothesis that the level of spinal block is related to the lumbar CSF bupivacaine concentration.

RESULTS

Men and women had CSF bupivacaine concentrations ranging from 95.4 to 773.0 microg ml(-1) (median 242.4 microg ml(-1)) and from 25.9 to 781.0 microg ml(-1) (median 187.6 microg ml(-1)), respectively. The large variability of bupivacaine concentrations obtained at similar times after subarachnoid administration made calculation of a meaningful half-life of bupivacaine in CSF impossible. There was no association between CSF bupivacaine concentration and spinal block level, and CSF bupivacaine concentrations for the same spinal block level differed between patients by six-fold.

CONCLUSIONS

There is a large variability of CSF bupivacaine concentrations in patients with an adequate level of spinal anaesthesia.

Large intrathecal volume: a cause of true failed spinal anesthesia

A 37-year-old woman scheduled for postpartum tubal ligation received two intrathecal doses of 2% hyperbaric mepivacaine (44 mg and 40 mg) and a subsequent single dose of 5% hyperbaric lidocaine (62.5 mg). Her sensory level never extended beyond S1. She subsequently underwent an uneventful general anesthetic, and had no residual sensory or motor deficits. An examination of the patient's lumbosacral magnetic resonance imaging (MRI) scan revealed an unusually large thecal volume. A large lumbosacral intrathecal volume may result in significant dilution or poor redistribution of hyperbaric local anesthetic. The final sensory level may be reduced or absent as a result. Intrathecal volume may be the most important non-modifiable factor affecting intrathecal distribution of local anesthetics; however, it cannot be easily measured or predicted. True failed spinal anesthesia should be distinguished from technical mishap, i.e., failing to introduce the anesthetic into the intrathecal space. The differential of a truly failed single-injection spinal anesthetic may include a large thecal volume, dural ectasias, cysts, and simple anatomic sacral restriction. To minimize maldistribution and neurotoxicity, the sum dose of all intrathecal local anesthetics administered for a single procedure should not significantly exceed the maximum recommended single-dose amount.

Complete failure of spinal anaesthesia in obstetrics

Intrathecal anaesthesia, either as a single shot-spinal or as part of a combined spinal-epidural technique, is now widely accepted as the management of choice for caesarean section. It generally produces rapid and predictable anaesthesia, yet occasionally fails for no apparent reason. Four case reports of seemingly inexplicable complete failure of intrathecal anaesthesia are presented, together with a literature review of other cases and possible causes of the failure, which include anatomical abnormality, drug failure and management failure.