Misc Topics

Question 1

What term describes the following: a stimulus that is normally expected to produce pain

Answer 1

allogenic

Question 2

What term describes the following: a stimulus that does not normally produce pain.

Answer 2

Allodynia

Question 3

Define dysesthesia

Answer 3

Abnormal or unpleasant sense of touch

Question 4

Provide an example of a condition that produces dysesthesia

Answer 4

Diabetic neuropathy that causes a burning sensation

Question 5

Where does pain modulation occur?

Answer 5

The spinal cord. During central sensitization, the inhibitory pathway can become impaired. This is why antidepressants that increase norepinephrine and serotonin can help treat chronic pain.

Question 6

List some examples of tricyclic antidepressants

Answer 6

Amitriptyline
Nortriptyline
Imipramine

TCAs have the most significant side effects including: QT prolongation and orthostatic hypotension

Question 7

List some examples of serotonin & norepinephrine reuptake inhibitors

Answer 7

Venlafaxine
Duloxetine
Minacipran

The combination of a SNRI and SSRI can precipitate serotonin syndrome

Question 8

What does CPRS stand for and what are the two types?

Answer 8

Complex regional pain syndrome

Type 1: reflex sympathetic dystrophy
Type 2: causalgia

Type 2 is always preceded by a nerve injury

Question 9

CPRS is characterized by what?

Answer 9

Neuropathic pain with autonomic involvement. Risk factors include females and previous trauma or surgery.

Question 10

List some treatments for CPRS

Answer 10

Ketamine
Memantine (NMDA antagonist)
Gabapentin
Regional sympathetic block
PT
Steroids
Amitriptyline

Question 11

What does the thoracic paravertebral nerve block target?

Answer 11

The ventral ramus of the spinal nerve as it exits the vertebral foramen. This block is used for breast surgery, thoracotomies and rib fractures. The block needs to be performed at each dermatome to be anesthetized

Question 12

What kind of coverage does a thoracic paravertebral nerve block provide?

Answer 12

This block creates a unilateral sympathetic and sensory block along each dermatome. It can be thought of as a unilateral epidural block

Question 13

List some common complications of a celiac plexus block

Answer 13

orthostatic hypotension
retroperitoneal hematoma
hematuria
diarrhea
abdominal aortic aneurysm
back pain
retrograde migration of injectate

Question 14

What type of pain is a cervical plexus block useful for?

Answer 14

Cancer pain of the abdominal organs including: stomach, liver, pancreas, distal esophagus and colon (except descending)

Question 15

What type of pain is a superior hypogastric plexus block used for?

Answer 15

Cancer pain to the pelvic organs including uterus, ovaries, prostate and descending colon

Question 16

What is the sphenopalatine block commonly used to treat?

Answer 16

post dural puncture headache

Question 17

Describe how the anatomy of the optic nerve impacts the type of anesthesia for a retrobulbar block

Answer 17

The optic nerve is actually part of the central nervous system. Because it is wrapped in the meningeal sheath and surrounded by CSF, injection of local anesthetic into the optic sheath provides direct entry to the brain - like a spinal for the optic sheath

Question 18

What complication can occur during a retrobulbar block if local anesthesia migrates toward the optic chiasm?

Answer 18

If LA migrates, it can anesthetize cranial nerve 2 and 3 on the opposite side and cause blindness in the contralateral eye (amaurosis)

Question 19

Why can apnea occur after a retrobulbar block?

Answer 19

Local anesthesia that reaches the brainstem can cause apnea (post retrobulbar block apnea). Usually occurs 2-3 minutes after the injection with spontaneous ventilation resuming 15-20 minutes later. Full recovery may take up to an hour

Question 20

What are some indications that post retrobulbar block apnea may occur?

Answer 20

Shortly after the block, if a pupil that was small has dilated, you should anticipate apnea and be ready to provide support until the local has cleared from the CSF

Question 21

What types of procedures are TAP blocks best suited for?

Answer 21

Procedures that involve T9-T12 distribution. Bilateral TAP blocks are needed from midline incisions or laparoscopic surgery.

Innervation of the anterolateral abdominal wall arises from the anterior rami of T7-L1

Question 22

What are the components of the triangle of Petit?

Answer 22

External oblique
Latissimus dorsi
Iliac crest

Question 23

What are complications of the a TAP block despite using ultrasound guidance?

Answer 23

Peritoneal puncture and liver hematoma. The tip of the needle should be positioned in the fascial plane between the internal oblique and the transverse abdominis muscle

Question 24

Inhibition of COX-1 causes what effects?

Answer 24

COX 1 is always present and is responsible for normal physiologic function. Inhibition of it can cause gastric irritation, reduced renal blood flow and impaired platelet function

Question 25

Inhibition of COX 2 produces what?

Answer 25

Analgesia, anti inflammatory and antipyretic effects. COX 2 is not always present and expressed during inflammation. Analgesia from COX 2 inhibitors has a ceiling effect unlike opioids.

Question 26

List some common non selective COX Inhibitors and then some COX 2 selective inhibitors

Answer 26

Non selective: aspirin, ibuprofen, naproxen, ketorolac, diclofenac

COX 2 selective: celecoxib and any drug with the suffix -coxib

Question 27

How do COX inhibitors increase the risk of brochospasm?

Answer 27

Decreased prostaglandins lead to leukotrienes that can induce a bronchospasm

Question 28

List some cardiovascular complications of COX inhibitor use

Answer 28

Increased risk of HTN, MI and heart failure. Complication rate is higher with COX 2 inhibitors compared to COX 1. COX 2 inhibitors were supposed to be associated with less side effects but increased CV risk has caused most to be removed from the market except Celebrex.

Question 29

How many morphine equivalents is 30mg ketorolac equal to?

Answer 29

IV ketorolac is equivalent to about 10mg morphine IV