1. Local Anesthetics Armamentarium
Dr. Rahaf Y. Al-Habbab BDS. MsD. DABOMS Diplomat of the American Boards of Oral and Maxillofacial Surgery 2012

2. Armamentarium used for Local Anesthesia
The Syringe
The Needle
The Cartridge

3. The Syringe
Types
Non-Disposable (Metallic non-aspirating or aspirating)
Disposable

4. Syringes (Non-Disposable)
Non-Aspirating Syringe
Aspirating Syringe

5. Syringes (Disposable)

6. Component of the Syringe
Threaded Hub
Metal Barrel
Piston (Plunger) with the Harpoon
Finger Grip
Thumb Ring
Needle Adaptor (Hub)
Harpoon
Piston Rod/Plunger
Barrel
Finger Grip
Thumb Ring

7. Syringes
The Harpoon ended plunger is designed to pierce the lower rubber stopper of the cartridge,
to help withdrawn for aspiration
Rubber Stopper

8. Loading the Cartridge The cartridge is inserted into
the syringe either from the side
or from the base.
Aspirating syringe has a device (Harpoon) that is attached to the piston which penetrates the rubber stopper.
Fixate the needle into the threaded hub, making sure it goes through the rubber diaphragm

9. Armamentarium used for Local Anesthesia
The Syringe
The Needle
The Cartridge

10. Components of the Needle
Needle End
Hub
The Bevel
The Shank
The Hub
The Syringe Penetrating End
Shank
Bevel

11. The Needle The Bevel: It is the point or tip of the needle.
The Shank (Shaft): Consist of the diameter of the lumen (needle gauge).
The Hub: It is the plastic or metallic piece that attaches to the syringe.
The Syringe Penetrating End: It is placed into the needle adaptor and perforates the rubber diaphragm of the cartridge.
Bevel

12. The Needle Needles are selected according to the length and gauge.
Gauge: The diameter of needle lumen
(27 or 30 most commonly used)
The smaller the number, the greater the lumen diameter
(30-gauge needle has smaller diameter than 25-gauge)

13. The Needle The Length: Measured from the hub to the tip
Maybe long or short.
Long: It is about 1 5/8 inches or 40mm
Short: It is about 1 inch or 25mm
To allow different depth penetration in the tissue with different techniques, leaving safety length of the needle during use.
The weakest portion of the needle is at the hub, so never insert a needle into the tissue up to the hub.

14. Safe Needle Management
One Hand Recapping Method
Plastic Housing

15. Management of Occupational Blood Exposure
If an exposure occurs:
Should stop immediately.
Wash wound with soap and water.
Antiseptic use and/or bleeding the wound have not been proven to reduce infection, however antiseptic use is not contraindicated.
Bleach and other caustic agents should not be poured directly into the wound.

16. Armamentarium used for Local Anesthesia
The Syringe
The Needle
The Cartridge

17. Anesthetic Carpule (Cartridge)

18. Cartridges Referred to as a Carpule.
Alkali and Pyrogen-free glass are used in the manufacture of the cartridges.
Cartridges contain either 2.2ml or 1.8ml of local anesthetic solution

19. Components of the Cartridges
Consist of Four Parts:
Cylindrical glass tube
Stopper (Plunger)
Aluminum Cap
Diaphragm
Aluminum cap with Rubber Diaphragm
Glass Cartridge
Stopper

20. Cartridges
The Stopper is Located at the end of the cartridge that receive the Harpoon of the aspirating syringe.
The stopper used to be treated with glycrin or wax as a lubericant, but now it is treated with silicone.
The upper rubber sealing cap is present at the top of the cartridge and surrounded by aluminum diaphragm.
The needle pierce the upper rubber cap when the cartridge is loaded.
Storage of cartridges in sterilizing solution is contraindicated because of the danger of contamination by seepage.

21. Carpule Contents Local Anesthetic Agent (To be discussed later)
Vasoconstrictor
Preservative
Vehicle

22. Carpule Contents Local Anesthetic Agent Vasoconstrictor Preservative
Vehicle

23. Vasoconstrictor
Duration and Depth of local anesthesia can be modified by the Amount of vasoconstrictor in the local anesthetic.
The lower the concentration of vasoconstrictor, the less the depth and duration of anesthesia.
Concentration of 1:80,000 or 1:100,000 is most commonly used.

24. Vasoconstrictor Vasoconstrictor used are:
Adrenaline (epinephrine, supranol) 1: to 1:
Noradrenalin (nor-epinephrine) 1:30 000
Neo-Synephrine: 1:2500
Neo-Cobefrin: 1:20 000
Octapressin (Felypressin) similar to that excreted by human posterior pituitary gland.

25. Why add vasoconstrictor to LA?
All LA has some degree of VD effect that leads to:
Increase rate of absorption.
Higher plasma level.
Decrease duration of action.
Increase bleeding at site of injection.

26. Advantages of Adding Vasoconstrictor
Decrease incidence of Toxicity by retarding drug Absorption as toxicity depends on drug amount in bloodstream.
Confines the anesthetic agent to localized area so it increase the effect and duration of anesthesia.
Reduce blood flow to the injected area, so produces bloodless field, prolong the effect of anesthesia with minimum amount of LA to produce the desired effect.
Retard the absorption of local anesthetic drug.

27. Side Effects of Vasoconstrictor Use
Marked elevation of blood pressure.
Tachycardia, as epinephrine stimulate the heart by direct action on the myocardium which result in increase heart rate and cardiac output.
Arrhythmia.
Severe Headache.
Elevate blood sugar level.
May participate in Thyroid crisis in Hyperthyroid patients.

28. Side Effects of Vasoconstrictor Use
Intravascular injection or increased concentration of the VC may produce
toxic manifestation such as Tachycardia, Hypertension, Palpitation, Tremors,
Headache, and Ventricular Fibrillation in rare cases.
These side effects last as long as the blood level of the drug remain elevated.

29. Dilution of VC Agent Dilution referred to as ratio.
1 to 1000 means that there is 1g (1000mg) of drug in 1000ml of solution.
Dilution of 1: or 1: are commonly used

30. Pharmacological Action of Adrenaline
It stimulates both alpha and beta receptors (responsible for excitatory and inhibitory effects)
It inhibits the action of vasodilatation of blood vessels of voluntary muscles and causes relaxation of bronchial muscles
It dilates blood vessels in skeletal muscle and myocardium
It constrict blood vessels in the skin

31. Pharmacological Action of Adrenaline
It increases the heart rate and forces myocardium contraction (patient may complain of palpitation)
It increases cardiac output and elevate blood pressure (systolic) and decrease diastolic pressure as it dilates blood vessels of skeletal muscles and of the heart causing decrease in peripheral resistance.

32. Carpule Contents Local Anesthetic Agent Vasoconstrictor Preservative
Vehicle

33. Preservative (Reducing Agent)
Vasoconstrictors are unstable in solution and may oxidize especially if exposed to sunlight, so solution color is turned into brown color.
Small quantity (0.1%) of sodium bisulphite is added to compete for the available oxygen and maybe oxidized to sodium bisulphate turning the solution into brown color (should be discarded)

34. Carpule Contents Local Anesthetic Agent Vasoconstrictor Preservative
Vehicle

35. Vehicle LA are weak bases that are insoluble in water.
Ringer’s lactate solution is added to minimize discomfort during injection and gives the required volume of anesthetic solution.

36. Ringer’s lactate Solution
Composed of:
0.5gm Sodium Chloride
0.04gm Calcium Chloride
0.02gm Potassium Chloride
Dissolved in 100ml water