Perivascular Axillary Block III: Blockade Following 40 ml of 0.5%, 1% or 1.5% Mepivacaine with Adrenaline

Abstract

Perivascular axillary blockade was performed on 90 patients with the aid of a catheter technique. All blockades were performed by the same anaesthetist, who practised perivascular axillary blockade three or four times a day. The patients were randomly allocated to three groups. The injected volume of local anaesthetic was constant in each group: 40 ml mepivacaine with adrenaline. The concentration and, consequently, the amount (mg) were variable factors: 1/2% (200 mg), 1% (400 mg) and 1 1/2% (600 mg). Sensory and motor blockade were tested 30 min after each injection. All three groups showed a high incidence of analgesia (70%-100%) in all cutaneous segments, and none of the blockades showed total failure of the sensory blockade. The lowest incidence of sensory blockade was found in the areas innervated by the axillary, the radial and the musculocutaneous nerves, but no difference was found between the groups. However, the motor blockade was found to improve with increasing concentration of local anaesthetic solution.

Increased body mass index and ASA physical status IV are risk factors for block failure in ambulatory surgery — an analysis of 9,342 blocks

“…Naja and Lonnqvist 15 recommend using a nerve stimulator for thoracic and lumbar paravertebral blocks in elderly patients and patients with cardiopulmonary disease, but the authors do not discuss ASA class as a predictor of block failure. Several studies 5,8,9 have also found that more experienced anesthesiologists have higher rates of surgical block. Therefore, patients at high risk for block failure, especially those with high ASA class who might benefit most from regional anesthesia, should be cared for by more experienced anesthesiologists.…”

Upper Extremity Blocks

“…When considering the total mass (dose) of a local anesthetic, decisions are best skewed toward using a lower volume, concentration, and dose. Although it may appear counterintuitive, the work of Vester-Andersen and colleagues, [15][16][17] along with other confirmatory investigations, [18][19][20] concentration-dependent neurotoxicity and dose-dependent systemic toxicity. Therefore, traditional local anesthetic volumes for an upper extremity plexus block are generally between 20 and 40 mL, depending on the approach chosen, and concentrations to produce surgical anesthesia should be 1.5% or less for lidocaine or mepivacaine, 0.75% or less for ropivacaine, and 0.5% or less for bupivacaine.…”

Perivaskuläre axilläre Plexusanästhesie

“…Vester-Andersen et al [37] haben mithilfe mehrerer Vergleichsstudien, in denen verschiedene Konzentrationen und Volumina von Mepivacain für diese Art der perivaskulären Plexusanästhesie untersucht wurden, ein Optimum für den Blockadeerfolg bei Verwendung von 50 ml 1%iger Mepivacainlösung gefunden. Diese Studien belegen, dass für die perivaskuläre Plexusanästhe-sie ein bestimmtes Volumen erforderlich ist, um einen ausreichenden Blockadeerfolg zu generieren [35,36,37]. Publikationen über mit dieser erstmals von Selander [26] beschriebenen perivaskulären Technik durchgeführte Blockaden bestä-tigen, dass es sich um eine einfach durchzuführende Methode handelt, deren wesentlicher Vorteil darin besteht, sowohl als "Single-shot"-Verfahren als auch als kontinuierliche Technik eingesetzt werden zu können [3,13].…”

“…In der hier vorgestellten Technik ist der N. musculocutaneus im Gegensatz zu alternativen axillären Blockaden in einem den übrigen Nerven (Nn. medianus, ulnaris) vergleichbaren Prozentsatz blockiert [4,5,35,36,37]. Probleme mit der Blutsperre werden bei dieser Technik lediglich bei 0,3% der Patienten gefunden [3].…”