Mod 4: Local Anaesthetic Adverse Effects

Question 1

Appropriate Injection technique is required to maximize pt comfort during an injection and involves what?

Answer 1

1. Tightly stretching skin at injection site
2. Inject needle perpendicular to skin
3. Rapid insertion of needle through skin
4. Injecting solution slowly
5. Using smallest yet effective volume

Question 2

Appropriate equipment to be used to maximize pt comfort, this should be?

Answer 2

Highest gauge needle and smallest syringe possible for particular clinical situation.

Question 3

Name 2 topical agents that may reduce pt discomfort during injection?

Answer 3

EMLA, ELA-max creams also ethyl chloride (cold spray) may be used

Question 4

The addition of Bicarbonate to LA’s can be useful in reducing pt discomfort how? and in what quantity?

Answer 4

By increasing the LA’s pH closer to physiological pH may reduce pain at injection site. 1cc of bicarbonate to 10cc of drug for Lidacaine, 0.1cc per 10cc of bupivicaine

Question 5

The closer to what temperature reduces pain of injection?

Answer 5

Body temperature 37 degrees C

Question 6

How can a pt be distracted in order to reduce pain of injection?

Answer 6

1. Talking to them.

2. Allowing pt to listen to music

Question 7

Local adverse reactions can occur with LA’s, Name them.

Answer 7

1. Nerve damage
2. Tendon damage
3. Vessel damage
4. Tourniquet effect
5. Broken needle
6. Infection
7. Intravascular Injection

Question 8

Name the 3 systemic adverse reactions.

Answer 8

1. Systemic Toxicity reactions
2. Hypersensitivity reactions
3. Vasovagal reactions

Question 9

Systemic Toxicity has 2 stages, early and late, which present differently, how?

Answer 9

In early stage the CNS stimulation is apparent - restlessness, excitability.
In later stage the CNS depression is noted - dizziness, oral numbness, confusion, tinnitus, double vision, tremors, muscle twitching, convulsions, seizure, coma, respiratory collapse.
The leads to CVS depression - decreased myocardial contractability, bradycardia reducing output and hypottension

Question 10

Prevention of systemic toxicity reactions involves?

Answer 10

1. Avoid IV injection (aspiration)
2. Assess liver function
3. Calculate MSD
4. Be aware of current Meds.

Question 11

What enzyme is responsible for metabolizing LA?

Answer 11

Cytochrome P4503A4 enzyme

Question 12

Specific Inhibitors of amide LA metabolism include?

Answer 12

Itraconazole, Ketoconazole (azole antifungals)
Erythromycin, clarythromycon, cyclosporin (macrolides)
Amprenavir, Indinavir, Nelfinavir, Ritonavir (HIV protease inhibitors)
Diltiezam, Mibefradil (calcium channel blockers)

Question 13

Describe the treatment protocol for Systemic toxicity.

Answer 13

1. Stop injection, withdraw allergen, reassure pt
2. Activate emergency plan
3. Time check determine if 911 assistance is required
4. Maintain/establish airway
5. O2 10l/min
6. CPR if needed
7. Tourniquet above injection site
8. Convulsions - Valium 10mg PO or 5mg IV
9. Establish IV
10. Hypotension - Ephidrine 0.5mg IM or IV
11. CV collapse - Atropine 0.4mg IV
12. Document after incident or transfer.

Question 14

Are allergic reactions more prevalent in ester’s or amide’s?

Answer 14

Esters

Question 15

What is responsible for most LA allergies?

Answer 15

PABA

Question 16

LA hypersensitivity usually occurs within how long?

Answer 16

30 mins of injection

Question 17

Anaphylaxis causes wide spread mast cell degranulation triggered by an allergen characterized by?

Answer 17

Histamine release
Vasodilation
Bronchospasm
Hypotension ultimately CV collapse

Question 18

Signs and symptoms of histamine release. and treatment.

Answer 18

S&S: Wheals, Hives, Pruritis
Rx:Benadryl (dyphenhydramine) 50-75mg IM
Decadron (dexamethasone phosphate) 4-8mg IM

Question 19

Signs and symptoms of vasodilation and treatment

Answer 19

S&S: Sweling of eyelids, lips, cheeks, pharynx, larynx, wheezing, cyanosis
Rx: Epinephrine 0.3-0.5mg of 1:1000 conc IM. q 15mins x 3
Benadryl (dyphenhydramine) 50-75mg IM
Decadron (dexamethasone phosphate) 4-8mg IM

Question 20

Signs and symptoms of bronchospasm and treatment

Answer 20

S&S: Wheezing, Dyspnea
Rx: Epinephrine 0.3-0.5mg of 1:1000 conc IM. q 15min x 3
Aerosol bronchodilator (ventolin, proventil) 2 puffs q 4-6

Question 21

Rx protocol for Hypersensitivity/anaphylactic reactions.

Answer 21

1. Stop injection, withdraw allergen, reassure pt
   2.Activate emergency plan
   3.Time check determine if 911 assistance is required
2. Trendelenberg position
3. Maintain/establish airway
4. O2 10l/min
   7.CPR if needed
   8.Epinephrine 0.3-0.5mg of 1:1000 conc IM. q 15min
   9.Tourniquet above injection site
   10.Epinephrine 0.2cc of 1:1000 conc Iat injection site
5. Benadryl (dyphenhydramine) 50-75mg IM
   12 Aerosol bronchodilator (ventolin)
   13.Decadron 6mg IM
   14.Establish IV
6. Document after transfer

Question 22

What are signs and symptoms of Vasovagal attack?

Answer 22

Tachycardia
Diaphorysis (cool/clammy)
Pallor
Hypotension

Question 23

Which LA can be used in Pregnancy? and what is its class?

Answer 23

Lidocaine, class B

Question 24

In pregnancy when should LA be avoided?

Answer 24

In 1st trimester