Dose requirement of local anaesthetic to produce grand mal seizure during stellate ganglion block

Abstract

Two case reports illustrate that low doses of local anaesthetics such as bupivacaine 2.5 mg and a mixture of bupivacaine i .25 mg and lidocaine 5 mg can induce grand real seizures if injected into the vertebral artery during stellate ganglion block.The effect of the dose of local anaesthetic agent and technique of administration into the stellate ganglion region discussed as is the relationship between vertebral artery blood flow and cerebral intravascular local anaesthetic concentration required to produce seizure activily. Suggestions are made concerning possible modification of the technique of anterior approach to the stellate ganglion, including test dose size, to reduce the incidence of inadvertent injection into the vertebral artery and subsequent central nervous system toxicity.KEY WORDS: ANAESTHETIC TECHNIQUES, regional, stellate block; COMPL1CA-XlONS, convulsions, local anaesthetics.THE ANTERIOR paratracheal approach at C61 is a technique commonly employed for blockade of the stellate ganglion. One of the serious potential complications with the use of this technique is inadvertent injection of the local anaesthetic solution into the vertebral artery. Previous case reports indicate that doses of bupivacaine as low as 7.5 mg and probably lidoeaine 10 mg can produce grand mal seizures when injected into the vertebral artery. 2"3 The symptoms associated with inadvertent injection of local anaesthetic into the vertebral artery range from transient nausea, dizziness, slurred speech and sedation to temporary blindness, loss of consciousness and, finally, grand mai seizures. The following two case reports document grand mal seizures that occurred during stellate ganglion block with doses of local anaesthetic much lower than those previously reported. The effect of mass of local anaesthetic agent and technique of administration of the drug into the stellate ganglion region is discussed, as is the relationship between vertebral artery blood flow and cerebral intravascular local anaesthetic coneentration required to produce seizure activity.Based on two case reports, some suggestions are made concerning possible modification of the technique of anterior approach to the stellate ganglion, including test dose size, to reduce the incidence of inadvertent intravertebral artery injection and subsequent central nervous system toxicity. CASE REPORTS Case IA diagnostic stellate ganglion block was planned for a 55 year old 60 kg man with diffuse burning pain in the left upper extremity.An intravenous infusion was established in the opposite arm. The patient was placed in a 20 degree head up position and the neck was fully extended. A paratracheal approach was used with a 25 gauge 3.75 cm needle attached to a 10 ml syringe. Bony contact was made at the level of C6 and the needle was then withdrawn 3 mm. Following negative aspiration, a test dose of 0.5 ml of bupivacaine 0.5 per cent was injected.Within five seconds after the injection generalized rigidity developed, which was followed by a grand mal seizure. The s...

The types and severity of complications associated with interscalene brachial plexus block anesthesia: Local and national evidence

“…34 Respiratory events including pneumothorax, 8 phrenic nerve palsy, 43 bronchospasm, 27,39 and reduction of pulmonary function tests 42 have also been reported, as have CNS complications such as central blocks, 14,17,32,38 permanent spinal cord injury, 6,32 and seizures. 15,23,24 Cardiovascular complications, such as myocardial infarction, 18 have been reported, as well as profound hypotension and bradycardia, which have been attributed to the Bezold-Jarisch reflex. 16 Local anesthetic toxicity can cause complications of CNS and cardiovascular function, including seizures, myocardial infarction, and arrhythmias.…”

Allergies to local anesthetics — the real truth

“…Les injections intra-artérielles d'anesthésique local, même en très petites quantités, dans la région de la tête et du cou provoquent des réactions toxiques généralisées. 11 Les réactions vasovagales, les réactions à l'épinéphrine, les crises de panique et les réactions toxiques généralisées aux anesthésiques locaux représentent la grande majorité des réactions défavorables qui surviennent dans ce cas. Les patients repartent souvent convaincus d'être allergiques à l'anesthésique local.…”

“…Intra-arterial injections of even minute quantities of local anesthetics in the head and neck region result in massive toxic reactions. 11 Vasovagal reactions, epinephrine responses, "panic attacks" and systemic toxic reactions to local anesthetics, account for the vast majority of adverse reactions occurring in patients in this setting. Patients frequently come away from these events convinced that they are allergic to the local anesthetic.…”

Iatrogenic vertebral artery injury

“…A total of 16 cases of VA-related complications in the percutaneous nerve block procedures was reported in the literature, which is summarized in Table 2 (63)(64)(65)(66)(67)(68)(69)(70)(71)(72)(73)(74)(75)(76). The complications occurred following stellate ganglion block procedures in the majority of cases.…”