Blocks of the Scalp

The scalp is supplied by branches of the trigeminal nerve (ventral portion) and the cervical plexus, both of which can be blocked by a subcutaneous injection of local anesthetic. Scalp blocks are performed using short, 25-gauge intradermal needles. After cleaning the scalp with a bactericidal solution, a circular line is drawn from the glabella to the occiput and divided into four parts at the intersections of the sagittal and frontal planes. Depending on the site of the lesion, a ring of anesthesia is provided along the selected quarter by injecting a solution of 0.5% to 1% lidocaine with a 1:200,000 concentration of epinephrine subcutaneously and intraperiosteally (and intramuscularly in the temporal fossa). The total dose must not exceed 10 mg/kg of lidocaine. These blocks are not commonly used in pediatrics. They are usually restricted to surgical repair of large wounds of the scalp in adolescents with a full stomach, and for most patients, local anesthesia by infiltrating the edges of the wound is preferable.