Referred Pain

Question 1

Pain definition

Answer 1

Unpleasant sensory and emotional experience associated with actual or potential tissue damage, or described in terms of such damage

Question 2

Pain pathways

Answer 2

Sensation picked up by peripheral nociceptors and then relayed to the posterior horn of the spinal cord
Travels in the spinothalamic tract to reach the contralateral cortex (through thalamus)

Question 3

2 types of pain fibers

Answer 3

Adelta (fast)

C (slow)

Question 4

Sympathetic innervation

1. Foregut
2. Midgut
3. Kidneys
4. Hindgut

Answer 4

1. Greater splanchnic nerve (T5-9/10)
2. Lesser splanchnic nerve T10-11
3. Least splanchnic nerve T12
4. Splanchnic lumbar nerves, sacral splanchnic nerves L1/2

Question 5

Do pain fibers travel along parasympathetic or sympathetic fibers to the spinal cord?

Answer 5

Sympathetic fibers

Question 6

3 functions of sympathetic innervation of the abdomen

Answer 6

Controls arterial blood flow through vasoconstriction
Tonic inhibitory influence on mucosal secretion
Inhibitory on smooth muscle

Question 7

Referred pain definition

Answer 7

Pain perceived in regions innervated by nerves other than those that innervate the site of noxious stimulation

Question 8

Projected pain definition

Answer 8

Stimulation of a sensory nerve along its path may induce pain that is projected to the tissue innervated by the stimulated nerve

Question 9

Somatic pain definition

Answer 9

The activation of peripheral nociceptors without actual damage to the nerves
Hurts where the damage is (bodily pain)

Question 10

Visceral referred pain vs somatic referred pain

Answer 10

Visceral: from visceral nerve to somatic area (inflammation of gut causes pain of the dermatomes on abdomen)
Somatic: between a somatic nerve and somatic area (irritation of diaphragm causes shoulder pain)

Question 11

Visceral pain

Answer 11

Stretching, distension, or ischemia of the viscera

Tends to be poorly localized and often ill defined

Question 12

McBurney’s point

Answer 12

1/3 of the way from the anterior-posterior iliac spine to the umbilicus
On the right

Question 13

Migration of pain in appendicitis

Answer 13

Initially the pain is felt in the mid-abdomen as visceral pain (from bowel distension, inflammation, ischemia, and transmitted by C fibers)
Migrates to the RLQ and is appreciated as somatic pain (direct irritation of the overlying somatic nociceptive nerves of the parietal peritoneum by inflammation/noxious agents)

Question 14

Rovsing’s sign

Answer 14

Pain in the right lower quadrant during left sided pressure suggests appendicitis
(Press on left side, say it hurts at McBurney’s point)

Question 15

Modified Rovsing’s sign

Answer 15

Right lower quadrant pain on quick withdrawal (referred rebound tenderness)
Because you slam the peritoneum onto the inflamed appendix
Push on the left side and then quickly remove hand and it hurts a lot at McBurney’s point

Question 16

Psoas and obturator signs

Answer 16

Flexion and movement irritate the retroperitoneal parietal peritoneum overlying the psoas and/or obturator muscles and evoke somatic pain sensation

Question 17

Cutaneous hyperesthesia

Answer 17

Picking up the abdominal skin is normally not painful, but in appendicitis may see localized pain

Question 18

Guarding

Answer 18

Tensing of the abdominal wall musculature when palpated

Question 19

Rigidity

Answer 19

Abdominal wall muscles so tense you can tap-dance on the abdomen
Constant guarding
Like when the appendix bursts

Question 20

Appendix is part of which segment of the gut?

Answer 20

Midgut

Question 21

Valentino’s syndrome

Answer 21

Perforated ulcer masquerading clinically as appendicitis

Big initial epigastric pain that migrated to the lower quadrant (because acid and food accumulated there)

Question 22

Biliary colic

Answer 22

Gallstones preventing gallbladder emptying

Upper abdominal visceral pain from stretch receptors in gallbladder wall, that may radiate around or through to the back

Question 23

Cholecystitis

Answer 23

More localized pain where the gallbladder is

Question 24

Murphy’s sign

Answer 24

As gallbladder becomes inflamed somatic pain is perceived in the right upper quadrant, with tenderness on deep inspiration

Question 25

Kehr’s sign

Answer 25

Left shoulder pain

From splenic rupture or other conditions that result in irritation to the diaphragm

Question 26

Post-laparoscopy shoulder pain

Answer 26

CO2 irritation of the diaphragm

Right side more than left

Question 27

What type of nerve is the phrenic nerve?

Answer 27

Somatic nerve
Innervates the diaphragm with motor and sensory nerves
Pain from the diaphragm is interpreted as pain from the C3-5 dermatomes (shoulder)