**Author details**

Technique:

18 Current Topics in Anesthesiology

feasible

cuff.

plied to puncture site.

• An IV cannula is inserted in the extremity opposite the block side.

is inflated followed by deflation the distal cuff.

**4. Local anaesthetics for peripheral nerve blocks**

• Anaesthesia onset is almost immediate.

(FDA) approval for this purpose [43].

application does not exceed 4 h [44].

**5. Topical anaesthetics**

• A double pneumatic tourniquet is placed with proximal cuff high on the upper arm.

bandage is wrapped around the arm to exsanguinate the extremity completely.

• Inject preservative‐free local anaesthetic (recommended maximum dose is 3 mg/kg).

• A peripheral IV cannula is placed on the limbs on which surgery is to be done as distal as

• The block arm is elevated for 1–2 min to allow passive exsanguination, and then, Esmarch

• The distal cuff is inflated to 50–100 mmHg above systolic BP after which the proximal cuff

• After injection IV cannula is removed from anaesthetised hand and pressure is quickly ap‐

• When the patient reports tourniquet pain inflate the distal cuff and deflate the proximal

There are a wide variety of local anaesthetic agents available for peripheral nerve blocks. Important points to consider when making the choice are onset and duration of action, dura‐ tion of the surgical procedure and anticipated degree of pain. Caution is to be used if one decided to use additives to local anaesthetics for peripheral nerve blocks to prolong their effect as none of the additives discussed in this chapter have got the Food and Drug Administration

Topical anaesthetics are used for procedures such as vein cannulation, laceration repair to avoid infiltrative local anaesthesia injections and associated pain. They are widely used in the paediatric population. There are many dosage forms in clinical use, for example, gels, sprays, creams, ointments, patches. Skin absorption is variable and accounts for the systemic toxicity. This complication is rare provided the skin is intact with the exception of 5% EMLA cream, a eutectic mixture of 2.5% lidocaine and 2.5% prilocaine. Commonly available forms are Ametop (4% tetracaine) and EMLA, and more recently, a 4% lidocaine topical cream has been introduced. It is better tolerated on the skin while having flexible application times. Onset of action for Ametop is between 30 and 40 min and has a duration of action of about 4–5 h. EMLA on the other hand has a slower onset of about 60 min with a short duration of action of about 2 h. Toxicity is largely related to the age of the patients and possible damage in the skin. It is recommended that in those below 3 months, duration of application should not be more than 1 h, while for age group between 3 and 12 months maximum duration of Jesse Musokota Mumba<sup>1</sup> \*, Freddy Kasandji Kabambi<sup>2</sup> and Christian Tshebeletso Ngaka2

\*Address all correspondence to: jesse@jesmuira.com

1 Head of Anaesthesia and Critical Care, Ondangwa Private Hospital, Namibia

2 Department of Anaesthesia and Perioperative Medicine, University of Cape Town, South Africa
