An overview of different techniques of local anesthesia used for minor surgical procedures.

1. Local anesthesia for
minor surgical
procedures

2. Contents
●Introduction & background
●Lignocaine as local anesthetic
●Preparation of the patient
●Safety hints for anesthetic usage
●How to Administer the Local Anesthetic
●Recommended Dosages of lignocaine
2

3. Introduction and
background
3

4. Local anesthetics
● Drugs which produce a reversible loss of
sensation in a localized part of the body when
applied directly onto nerve tissues or mucous
membranes
● Local anesthetics are ‘local’ only because of
how they are administered.
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5. General considerations
● In most cases the technical aspect of administering
anesthesia for a minor surgical procedure in an office or
outpatient department to an ambulatory patient presents
no particular difficulty or problem.
● The pharmacologic actions of the anesthetic agents
employed are precise and predictable; thus the results
are satisfactory in most instances.
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6. Background
● Local anesthetics work by reversibly blocking nerve conduction.
● They primarily block the sensation of sharp pain; they do not
block pressure sensation.
● Therefore, in an area that has been adequately anesthetized, the
patient will not feel the sharp needle stick during suture
placement but may feel a vague sensation of pressure.
● This information should be shared with the patient.
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7. “It is imperative to realize that the old axiom that
the skill and knowledge is more important than
the agent or method employed
applies only if adequate equipment for
administration as well as management of all
possible complications is available.
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8. Lignocaine as local
anesthetic
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9. Lignocaine as LA
● A local anesthetic can be defined as a drug which reversibly
prevents transmission of the nerve impulse in the region to which it
is applied, without affecting consciousness.
● The efficacy profile of lignocaine as a local anesthetic is
characterized by a rapid onset of action and intermediate duration of
efficacy.
● Therefore, lignocaine is suitable for infiltration, block, and surface
anesthesia.
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10. Lignocaine – mechanism of action
● Lignocaine blocks fast voltage-gated sodium channels in the cell
membrane of postsynaptic neurons, preventing depolarization and
inhibiting the generation and propagation of nerve impulses.
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11. Lignocaine with adrenaline
Role of adrenaline
●Adrenaline constricts blood vessels, through its action on the adrenergic
receptors found in the walls of blood vessels.
●It is used to slow the dispersal, and thereby prolong the effect, of local
anaesthetics and reduce the systemic exposure of the drug and therefore
reduce the potential for adverse drug reaction.
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12. Lignocaine with adrenaline
Advantages of the combination
Because of vasoconstriction effect of adrenaline:
●Prolongs effect of local anesthesia
●Reduces systemic side effects
●Reduces bleeding at surgical site
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13. Lignocaine with adrenaline
Precautions
Not to be used in
● Children under 12 years of age.
● People who are allergic to other amide-type local anaesthetics
● Anaesthesia of the fingers, toes, tip of nose, ears or penis.
● The injection should not be given into a vein, or into inflamed or
infected tissues.
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14. Preparation of the
patient
Preoperative considerations
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15. Preparation of patient and preoperative
considerations
● Complete histories, physicals, and the usual laboratory studies are to be
carried out
● patients then arrive in the outpatient department several hours before surgery
and receive preoperative medication, usually in smaller amounts than in-
patients
● They are anesthetized in the usual manner with minimal amounts of various
anesthetic agents during the surgical intervention and are then kept in a
recovery room until able to return to their homes with the aid of an escort.
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16. Preparation of patient and preoperative
considerations
Ambulatory surgical patient should be managed
like the hospitalized surgical patient:
● The signing of a consent form
● withhold all solid foods and fluids at least 6-8
hours before surgery; and pre-medication
according to specific needs.
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17. Choice of anesthesia
● Local and regional anesthesia have numerous advantages
that are particularly apparent in office anesthesia.
● It is the safest method of anesthetizing patients who have
eaten recently because the incidence of vomiting with
tracheo-bronchial aspiration is very low.
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18. Choice of anesthesia
● The patient is conscious throughout the operation and is
therefore able to cooperate with the surgeon.
● The patient should be able to leave the office unassisted
after a short waiting period.
● A minimum of equipment and technical help is required.
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19. Choice of anesthesia
● Local or regional anesthesia does not produce amnesia,
and the incidence of anesthetic emergencies is
substantially lower than with other methods.
● Most regional block procedures can be performed safely
in the office for minor surgical procedures.
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20. Principles to render anesthetic agents as safe as
possible
● Employ the weakest effective solution that will
accomplish the desired effect.
● Terminate the injection at the slightest sign of
an overdose.
● Observe the patient carefully at all times and
be properly prepared to treat complications.
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21. Principles to render anesthetic agents as safe as
possible
● The maximum dose of local anesthetic agent
administered for a specific surgical procedure
varies with agent, operation, age, and physical
status of the patient.
● Vasoconstrictor agents, such as epinephrine,
are added to most local anesthetic agents- to
decrease -their rate of absorption and prolong
the duration of effective analgesia.
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22. Dosing and administration technique
PATIENT FACTORS IN DOSING
● Before injecting patients with an LA, it is
important to consider their age, comorbidities,
and medications, as all of these are factors in
dosing decisions.
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23. PATIENT FACTORS IN DOSING
● Infants younger than 4 months of age have been shown to have
higher plasma concentrations of LAs when given the adult
equivalent dose
● The elderly, those older than 70 years, also deserve special
dosing considerations.
● Diminished blood flow to those organs responsible for
metabolism of LAs leads to decreased plasma clearance of
LAs in those affected.
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24. PATIENT FACTORS IN DOSING
Renal impairment
● Lidocaine appears to be very well tolerated. Lidocaine is
metabolized by a hepatic route. Plasma clearance of lidocaine
is unchanged in the renal patient. Dosing guidelines are
unchanged.
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25. PATIENT FACTORS IN DOSING
Hepatic impairment
● Amide Las are mainly metabolized via the liver, so hepatic
dysfunction would greatly alter plasma concentrations of LAs.
● patients with end-stage liver disease have a 60% decrease in
plasma clearance rates of Las
● under normal office minor procedure circumstances, no
reduction in dosing is recommended for isolated mild hepatic
impairment. 25

26. PATIENT FACTORS IN DOSING
Cardiac disease
● For patients with well-controlled disease, no dosage
adjustment is required.
● For patients with more severe disease, a reduction of as much
as 20% for repeat regional block has been recommended
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27. Safety hints for
anesthetic usage
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28. Safety hints for anesthetic usage
Caution about injections
● It is quite dangerous to insert the syringe needle in the wrong place
and inject the solution into an artery by mistake.
● A good habit to develop when giving any type of injection is to draw
back on the syringe (i.e., pull back on the plunger) before injecting
the solution.
● If you draw back and get blood, reposition the needle and draw
back again. This technique prevents an accidental intra-arterial
injection, which can cause serious complications. 28

29. Safety hints for anesthetic usage
Caution about maximal safe dosage
● Be aware of how much you are injecting to avoid exceeding the
safe doses.
● Average-sized wounds (up to 4–5 cm) usually present no problem,
but it is easy to forget about dosage concerns when you are
working on larger wounds.
● All anesthetic agents have systemic as well as local effects.
● The safe dosage is based on the total weight of the patient
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30. How to Administer the
Local Anesthetic
Techinques
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31. 1. Direct Infiltration Around the Wound
● In many cases, injecting the anesthetic agent
around the wound is an easy and reliable way
to anesthetize the area.
● It is best to use as small a needle as possible
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32. 1. Direct Infiltration Around the Wound
● You can inject directly into the wound to get
the anesthetic into the surrounding
● skin if the wound is reasonably clean.
Alternatively, inject in the non-injured skin
along the outside of the wound. Inject until
you see the skin start to swell.
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33. 1. Direct Infiltration Around the Wound
● One technique is to push the needle into the
tissues completely to the hub, and then slowly
infiltrate the anesthetic as you bring the
needle out of the tissues.
● Be sure to allow enough time for the agent to
take effect before starting your procedure (at
least 5 minutes).
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34. 2. Nerve Blocks
● In some areas of the body, discrete nerves that are responsible
for sensation to the injured area are easy to locate.
● In these instances, local anesthesia can be infiltrated around (not
into) the sensory nerve for pain control to the area around the
wound.
● This approach is advantageous because the patient needs to
undergo fewer injections than if you anesthetize the entire wound
margins directly.
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35. 2. Nerve Blocks
● Nerve blocks are also a good choice when the wound is deep,
because they often give a more complete block of the entire area,
not just the skin.
● This approach is especially appropriate for larger wounds,
because it usually requires less anesthetic agent than direct
infiltration.
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36. 3. Nerve Blocks for Hand Injuries
● Digital Block
● Wrist Block
Note: Epinephrine should not be used for anesthetizing the hand and
fingers.
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37. Digital block
● A digital block is the best way to evaluate and
treat a wound on the finger.
● The digital nerves supply sensation to the
volar and dorsal surfaces of the finger.
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38. Digital block – procedure
1. The injection is done from the dorsal (not volar) surface near the
metacarpophalangeal (MCP) knuckle.
2. Insert the needle into the web space, when present (the thumb and little finger are not
bordered on both sides by web spaces).
3. Aim the needle toward the MCP joint of the affected finger, moving in a volar direction.
4. Be careful not to inject too superficially on the volar side, or your injection will miss the
area around the nerve.
5. Inject 2–3 ml of solution into each side of the affected finger.
6. Infiltrate 1–2 ml along the dorsal skin of the digit, just distal to the MCP knuckle.
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39. Digital block – procedure
39

40. Wrist Block
● Three nerves supply sensation to the hand: the median
nerve, ulnar nerve, and superficial branch of the radial
nerve.
● If you infiltrate around all three nerves, you effectively
anesthetize the entire hand.
● If an injury is within the distribution of any one or two
nerves, simply infiltrate around the nerves that you need
to anesthetize, based on the injury.
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41. Wrist Block
41

42. Wrist Block – median nerve
● The median nerve supplies sensation to the volar surface
of the hand, from the lateral half of the ring finger to the
thumb, and to the dorsal aspect of the fingers distal to
the PIP joint, from the lateral half of the ring finger to the
thumb.
42

43. Wrist Block – median nerve
Wrist block, median nerve. PL = palmaris longus, FCR = flexor carpi radialis 43

44. Wrist Block – median nerve (procedure)
1. Have the patient flex the wrist. The FCR and PL (if present) become
noticeable in the distal forearm; the FCR is the more lateral of the two
tendons.
2. Insert the needle just proximal to the wrist crease and medial to the FCR
tendon.
3. Draw back on the syringe and slowly inject 3–5 ml of anesthetic in the
tissues deep to the skin.
4. If the patient describes minor tingling, the needle is in the proper position. If
the patient describes electric shocks or severe pain, the needle may be in
the nerve. Stop injecting the anesthetic, and back the needle out a few mm
before continuing to inject the anesthetic solution. Do not inject the
anesthetic directly into the nerve.
44

45. Wrist Block – Ulnar Nerve
● The ulnar nerve supplies the remainder of the volar
surface of the hand and the volar and dorsal surfaces of
the ring and little fingers.
● The dorsal ulnar side of the hand is innervated by a
branch of the ulnar nerve that comes off proximal to the
wrist in the distal forearm.
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46. Wrist Block – Ulnar Nerve
46Wrist block, ulnar nerve. Note that the nerve lies between the artery and
flexor carpi ulnaris (FCU) tendon.

47. Wrist Block – Ulnar Nerve (procedure)
1. Have the patient flex the wrist. The FCU is palpable along the medial
edge of the distal forearm.
2. Insert the needle just proximal to the wrist crease and just lateral to
the FCU tendon.
3. Draw back on the syringe before injecting the anesthetic to ensure
that the needle is not in the ulnar artery. If blood is drawn back,
remove the needle and hold pressure over the area for several
minutes.
47

48. Wrist Block – Ulnar Nerve (procedure)
4. Slowly inject 1–2 ml of local anesthetic.
5. To block the nerve branch that supplies sensation to the dorsal
aspect of the hand, inject 1 ml of local anesthetic subcutaneously in
the tissues overlying the ulnar nerve.
6. Advance the needle onto the dorsum of the wrist, and inject another
3–4 ml. Go about halfway around the wrist on the dorsal surface.
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49. Wrist Block – Superficial Branch of the Radial Nerve
● The superficial branch of the radial nerve supplies
sensation to the dorsum of the hand from the ring finger
to the thumb; the dorsum of the thumb; and the dorsum of
the index, middle, long, and ring fingers to the PIP joint.
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50. Wrist Block – Superficial Branch of the Radial Nerve
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51. Superficial Branch of the Radial Nerve (procedure)
1. Feel for the radial artery pulse in the distal forearm, approximately 2
cm proximal to the wrist crease.
2. Insert the needle laterally to the point where you feel the pulse, and
inject 1–2 ml of local anesthetic subcutaneously. Draw back on the
syringe before injection.
3. Advance the needle into the tissues on the dorsum of the distal
forearm.
4. Inject an additional 3–4 ml of solution halfway around the dorsal
surface of the wrist.
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52. Ankle blocks
● Excellent for exploration and repair of sole
lacerations.
● The sural nerve supplies a variable part of the
heel and lateral border of the sole, the tibial
nerve the rest.
● Three other nerves supply the dorsum of the
foot.
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53. Ankle blocks
53

54. Tibial Nerve
● The landmark is the midpoint between the most prominent point of the
medial malleolus and the Achilles tendon.
● The tibial artery pulse may be felt and the nerve wraps around this.
● Advance the needle such that it feels it would just slide behind the tibia
~0.5-2 cm depending on patient size.
● If you hit bone you are to anterior or too deep.
● Infiltrate ~0.1mls/kg (max 5mls) of LA and massage.
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55. Facial Nerve blocks
● Vital for accurate repairs of the vermillion border of the lip.
● In younger children used in conjunction with sedative agent. Blocking
nerves bilaterally is necessary for central lacerations.
● Standard technique is ~0.05 mls/kg (max 2.5mls) 1% lignocaine using
25G needle and 3 ml syringe for both.
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56. Infraorbital Nerve block
● Supplies medial cheek and upper lip. Does not cover gums, teeth or nose.
Exits through the infraorbital foramen. This is a large foramen that can
be located medial to the zygomatic arch in a line between the pupil and
upper canine.
● It is most easily accessed from the intraoral route. One hand lifts lip then
insert needle at reflection of the oral mucosa above canine.
● Advance ~0.5-1cm towards foramen, do not attempt to enter foramen as
retrograde spread of LA can produce very extensive facial blocks.
● Infiltrate gently and massage as with usual technique.
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57. Infraorbital Nerve block
57

58. Mental nerve block
● Supplies chin and lower lip (not gums or teeth).
● Exits mandible through the mental foramen, a small foramen
located in the middle of the mandible just posterior to the
lower canine.
● The intraoral route is again easier. Evert the lip, insert the
needle ~0.5-1cm at the reflection of the oral mucosa just
posterior to the canine.
● Inject gently and massage. 58

59. Mental nerve block
59

60. Recommended Dosages
of lignocaine
60

61. Recommended Dosages of lignocaine
61
Xylocaine injection (without epinephrine)
Procedure Conc (%) Vol (ml)
Total dose
(mg)
Infiltration
Percutaneous 0.5 or 1 1-60 5-300
Intravenous regional 0.5 10-60 50-300

62. Recommended Dosages of lignocaine
62
Xylocaine injection (without epinephrine)
Procedure Conc (%) Vol (ml)
Total dose
(mg)
Peripheral Nerve Blocks
Brachial 1.5 15-20 225-300
Dental 2 1-5 20-100
Intercostal 1 3 30
Paravertebral 1 3-5 30-50
Pudendal (each side) 1 10 100

63. Recommended Dosages of lignocaine
63
Xylocaine injection (without epinephrine)
Procedure Conc (%) Vol (ml)
Total dose
(mg)
Paracervical
Obstetrical analgesia
(each side)
1 10 100
Sympathetic Nerve Blocks
Cervical (stellate
ganglion)
1 5 50
Lumbar 1 5-10 50-100

64. Recommended Dosages of lignocaine
64
Xylocaine injection (without epinephrine)
Procedure Conc (%) Vol (ml)
Total dose
(mg)
Infiltration
Percutaneous 0.5 or 1 1-60 5-300
Intravenous regional 0.5 10-60 50-300

65. 65