Topical local anaesthesia

Callear AB. The effect of temperatnre on the discomfort caused by topical local anaesthesia. J R Soc Med 1995 88(12) 709p-llp. 

Its solution finds usage as a topical local anaesthesia in dentistry. It has also been employed in several ear and nose drops for the relief of pain along with other drugs. 

Bone scintigraphy involves venepuncture, a time delay following injection of the isotope and a significant subsequent period immobilised on the scanner. Topical local anaesthetic should be used prior to venepuncture. Play therapy should be utilised as the use of play specialists has been shown to reduce the need for general anaesthesia (Department of Health 2003). 

The site of drug action means where a drug acts and mechanism means how the drug acts. Drug which act only at the site of application (i.e. localized region) are termed as local or topical action for example, ointments, paste, creams and certain other local preparations used externally produce only local effect. The local anaesthetics like lignocaine, procaine produce anaesthesia (local) in a localized region only. 

Local anaesthetics can be applied topically, deposited around peripheral nerves, or infiltrated into tissues. Central neural blockade can be produced by injection into the subarachnoid or epidural spaces. Less common uses are for intravenous regional anaesthesia and attenuation of cardiovascular responses to tracheal intubation. The membrane-stabilising effect of local anaesthetics has been utilised in the treatment of myocardial arrhythmias. 

Topical anaesthesia prior to venepuncture may be necessary. This technique with EMLA (eutectic mixture of local anaesthetics) cream may be used by radiographers under patient group directions. See Chapter 12. 

---