From the Guidelines
For a motor point block diagnostic procedure, the recommended amount of 2% lignocaine (lidocaine) is typically 1-3 ml per motor point, with a maximum dose not exceeding 4.5 mg/kg of body weight or approximately 300 mg in an average adult, as recommended by guidelines for local anesthetic use 1.
Key Considerations
- The dose should be calculated based on the patient's weight to avoid systemic toxicity.
- The procedure should be performed with a 25-27 gauge needle, injecting slowly after negative aspiration to confirm the needle is not in a blood vessel.
- The onset of action is rapid, within 2-5 minutes, and the duration of effect is approximately 1-2 hours.
Local Anesthetic Guidelines
- The maximum recommended dose of lidocaine with epinephrine is 7.0 mg/kg, as stated in the guidelines for monitoring and management of pediatric patients before, during, and after sedation for diagnostic and therapeutic procedures 1.
- The use of epinephrine in local anesthesia is recommended for its benefits in reducing bleeding and prolonging the duration of anesthesia, as discussed in the guidelines for the use of local anesthesia in office-based dermatologic surgery 1.
Patient Safety
- Patients with stable cardiac disease can safely undergo local infiltration anesthesia with epinephrine, but consultation with a cardiologist is recommended if there are concerns about the patient's ability to safely undergo the procedure 1.
- The addition of hyaluronidase to infiltration anesthesia may enhance diffusion of the anesthetic solution, but its benefits in dermatologic procedures are unclear, and it should not be administered to patients with a history of bee sting allergy 1.
From the Research
Motor Point Block Diagnostic with 2% Lignocaine
- The amount of 2% lignocaine for motor point block diagnostic is not directly stated in the provided studies.
- However, the studies provide information on the maximum recommended doses of lignocaine for local analgesia:
- A study published in 1991 2 recommends a maximum dose of 500 mg for plain lignocaine and 670 mg with adrenaline for the infiltration technique of local analgesia.
- Another study published in 1995 3 found that a dose of lignocaine 900 mg with adrenaline did not produce toxic symptoms in 17 adult patients.
- It is also important to note that the concentration of lignocaine can affect the maximum recommended dose:
- The 1991 study 2 states that concentrated 1% and 2% solutions should not be used for the infiltration technique, while the 0.2% solution can permit the use of even higher dosages.
- Other studies provide information on the pharmacokinetics and pharmacodynamics of local anesthetics, including lignocaine:
- A study published in 1984 4 discusses the blood level of local anesthetics and how it is determined by the rate of uptake, tissue redistribution, metabolism, and excretion.
- A study published in 2014 5 discusses the properties and current utility of mepivacaine, another local anesthetic.
- A study published in 1995 6 discusses the effects of alkalinization on the potency of local anesthetics, including lignocaine.