Lecture 8 Intro to Analgesia Techniques Part 2 Flashcards
1
Q
- Sites of Action of Local Anesthetics in Pain Pathway
- How do they generally work?
A
- Inhibit Transduction & Transmission
- Block influx of sodium across cell membrane of nerve axons & inhibit conduction of action potentials
2
Q
- How long does lidocaine last if given locally
- Can you keep going lidocaine for pain?
- Which species should you not give iv?
A
- Quick onset, short duration (1-2 hrs)
- Need to remember Toxic dose so have to be careful not to give all
- Dogs: 10mg/kg, Cats: 5mg/kg
- Cats => Do NOT give IV
3
Q
- How long is the onset for bupivicaine
- Duration?
A
- 20min (longer than lidocaine)
- 4-6 hrs (longer than lidocaine)
4
Q
- Does bupivacaine have preservative in it?
- What mode can you not give it?
A
- preservative free**
- Aseptic technique
- NEVER give Bupivacaine IV!!!
5
Q
What drug can you give to help IV catheterization?
A
- Local block of lidocaine with NaHCO3 (so it doesnt sting)
- Aids in placement/success
↓ struggling, stress
6
Q
How to do a Testicular block
A
–2.0mg/kg, divided into each testicle
–I do not block spermatic cord or use bupivacaine
7
Q
How to do an Incisional block
A
- Wound infiltration involves injection of local anesthetic directly into surgical field or incision
- simple, safe, inexpensive
8
Q
Incisional block – Recommendations
A
- Simple, inexpensive, little-no risk if performed correctly
- Individual patient variation in pain threshold, need for additional analgesics, incisional pain
- Perform incisional block pre-skin or pre-linea incision
- (Savvas 2008) => Pre-operative incisional bupivacaine => significantly lower pain scores, ↓ additional analgesics compared to saline or PO incisional block
- Use bupivacaine, repeat @ closure depending on time
9
Q
What are different nerves that can be blocked
A
- Dental*
- Mandibular, infra-orbital, maxillary
- Retrobulbar*
- Femoral/Sciatic*
- Brachial plexus
- RUMM
- Digital
- Intercostal
10
Q
What drug do you usually use dental blocks
A
- Bupivacaine
- Additional 50% LA can be administered for infraorbital nerve block
11
Q
When giving dental blocks what must you always do
A
- Always calculate maximum cumulative dose:
- **BEWARE OF CUMULATIVE LA DOSE LEVELS**
12
Q
- How do you do a Mental Nerve Block
- What does it block?
A
- Middle mental foramen is largest of the three
- Palpate mental foramen just ventral to rostral (mesial) root of 2nd premolar
- Advance needle into opening of foramen in rostral to-caudal direction, slowly inject
- Digital pressure over injection site for 30 to 60 seconds to ensure caudal diffusion into mandibular canal
- Anesthetizes all oral tissues rostral to 2nd premolar on infiltrated side
13
Q
- What are the techniques of the mandibular (inferior alveolar) block?
- What does it anesthetize?
A
- Two techniques: extraoral & intraoral
- Anesthetizes the bone, teeth, soft tissue & tongue on infiltrated side
14
Q
How do you do the Mandibular (Inferior Alveolar) – Extraoral Technique
A
- Palpable notch on ventral mandible cranial to angular process
- If notch cannot be palpated (cats, some dogs) select point on ventral mandible located on a vertical plane with lateral canthus
- Insert & advance needle dorsally along lingual aspect of mandible to midpoint between ventral & dorsal borders of mandible => mandibular foramen where inferior alveolar nerve enters mandibular canal
- Aspirate & slowly inject
Notes:
- Finger placed inside mouth along mandible to palpate foramen & location of needle
- Clinical tips: Keep needle close to mandible with bevel directed toward bone
15
Q
How is a Mandibular (Inferior Alveolar) – Extraoral Technique done
A
- Palpate mandibular foramen intra-orally on lingual surface of mandible
- Needle advanced thru mucosa adjacent to foramen at level of last lower molar tooth
- Needle directed ventro-caudal towards angular process of mandible
- Aspirate & inject slowly
16
Q
How do you do an infraorbital block
A
- Palpate infraorbital foramen in maxilla dorsal to caudal root of upper 3rd premolar
- Insert needle through buccal mucosa in caudal direction, advance needle to entrance of foramen
- Aspirate & inject slowly
18
Q
Go over Infraorbital nerve anatomy
A
- Infraorbital nerve is rostral continuation of maxillary nerve
- Maxillary/infraorbital nerve gives off caudal superior alveolar nerve before entering canal =>
- supplies maxillary 4th premolar & molars
- Within canal it branches to middle superior alveolar nerves => innervate premolars
- Rostral superior alveolar nerves branch just before exiting infraorbital canal to innervate canine & incisor teeth
21
Q
Maxillary Nerve Block anatomic landmarks
A
- Blocked @ distal end before enters foramen
- Nerve runs close to maxillary artery, ventral to ocular globe, zygomatic salivary gland & deep facial vein
22
Q
How do you do the Maxillary N. Block Intraoral/Maxillary Tuberosity approach
A
- Palpate notch where zygomatic arch meets bone surrounding last upper molar
- Insert needle directly adjacent to bone at this level
- Keep needle perpendicular to hard palate
- Advance needle dorsally to level just beyond root tips of last molar
- Aspirate & inject slowly
23
Q
How do you do Maxillary N. Block Infraorbital approach intra-oral
A
- Same as infra-orbital nerve block
- Insert thin, long needle into infraorbital foramen to ~ level of medial canthus and/or ↑ volume LA injected
- May be high risk of injury to neurovascular structures in canal
