Sign Out
Click on icon to see table/diagram/imageRecommended doses: The previously suggested concentrations and volumes serve only as a guide. Toxic doses vary widely between patients and toxic effects may occur after any local anaesthetic procedure.
Careful observation of the patient must therefore be maintained. It is recommended that the dose of lidocaine at any one time should not exceed 3 mg/kg . However, the dose administered must be tailored to the individual patient and procedure, and the maximum doses here quoted should be used as a guide only.
Hypotension: During thoracic, lumbar and caudal epidural anaesthesia, a marked fall in blood pressure and/or intercostal paralysis may be seen, possibly due to the use of excessive doses, improper positioning of the patient or accidental disposition of the anaesthetic within the subarachnoid space. Hypotension and bradycardia may occur as a result of sympathetic blockade.
Test dose: For epidural anaesthesia, a 3-5 mL test dose of a local anaesthetic solution preferably containing up to 15 micrograms of adrenaline should be administered.
Verbal contact and repeated monitoring of heart rate and blood pressure should be maintained for 5 minutes after the test dose after which, in the absence of signs of subarachnoid or intravascular injection, the main dose may be administered.
Use of a test dose containing adrenaline may have further advantages in that an intravascular injection of adrenaline will be quickly recognised by an increase in heart rate, usually within about 40 seconds. To detect this, the heart rate and rhythm should be monitored with an electrocardiogram.
Prior to administration of the total dose, aspiration should be repeated. The main dose should be injected slowly, with continual assessment of the patient. If toxic symptoms or signs occur, the injection should be stopped immediately.
