Adjuncts To Anesthesia

Question 1

Aspiration of ____ of volume at a pH of < _____ will be sufficient to produce aspiration pneumonia

Answer 1

25 ml; 2.5

Question 2

Risk factors for aspiration

Answer 2

Full stomach, intestinal obstruction, hiatal hernia, obesity, pregnancy, reflux, emergency sx, & inadequate depth of anesthesia

Question 3

How can you reduce risk of aspiration during induction?

Answer 3

RSI & sellick’s maneuver (cricoid pressure)

Question 4

How do anesthetics increase the risk of aspiration?

Answer 4

Decrease LES tone, and decrease or obliterate gag reflex

Question 5

What type of cells have the highest concentration of Histamine?

Answer 5

Basophils & mast cells

Question 6

Effects of H1 activation on broncial smooth muscle and pulmonary beds

Answer 6

Bronchoconstriction and pulmonary vasodilation

Question 7

Effects of H2 activation on broncial smooth muscle and pulmonary beds

Answer 7

Mild bronchodilation and histamine-mediated pulmonary vasoconstriction

Question 8

H__ receptor activates phospholipase C, while H__ activates cAMP

Answer 8

1; 2

Question 9

Increases capillary permeability & ventricular irritability.
Contraction of intestinal smooth muscle
Attracts leukocytes & induces synthesis of prostaglandin

Answer 9

H1 receptor

Question 10

Increases HR & contractility
Increases gastric acid secretion
Suppresses T lymphocytes

Answer 10

H2 receptors

Question 11

How do H1 & H2 affect peripharal & coronary arteries?

Answer 11

Dilation

Question 12

Located on histamine-secreting cells & mediated negative feedback inhibiting synthesis & release of additional histamine

Answer 12

H3 receptor

Question 13

Metabolizes histamine to inactive metabolites that are excreted in urine

Answer 13

Histamine-N-methyltransferase

Question 14

Although ___ blockers prevent bronchoconstrictive response to histamine, they are ineffective in treating _____

Answer 14

H1; bronchial asthma

Question 15

How do H1 blockers affect ventilatory drive?

Answer 15

Cause significant sedation, but ventilatory drive is unaffected in the absence of other sedatives

Question 16

Why do newer (2nd generation) H1 blockers produce little or no sedation? (Loratidine, fexofenadine, cetirizine)

Answer 16

Limited penetration of BBB

Question 17

Dose of diphenhydramine

Answer 17

25-50 mg (0.5 - 1.5 mg/kg) q 4-6 hrs

Question 18

Which H2 antagonist can be given safely over 2 min w/o SE?

Answer 18

Famotidine

Question 19

_____ decreases hepatic flow & binds p-450. Which H2 antagonists do not effect p-450?

Answer 19

Cimetidine; ranitidine (weak), Famotidine, nizatidine

Question 20

Antacids _____ gastric pH and ________ intragastric volume

Answer 20

Raise, increase

Question 21

Which is better for aspiration, particulates or nonparticulates?

Answer 21

Nonparticulates. Particulates are as bad as acid aspiration

Question 22

Nonparticulates lose their effectiveness ______ after ingestion

Answer 22

30-60 min

Question 23

Antacids slow rate of absorption for which drugs?

Answer 23

Digoxin, cimetidine, & ranitidine

Question 24

Antacids quicken rate of elimination for what?

Answer 24

Phenobarbital

Question 25

Dose and onset of regaln

Answer 25

10-20 mg (0.25mg/kg); 1-3 or 3-5 min onset

Question 26

Reglans prokinetic action in upper GI is not dependent on _____ but is abolished by ______

Answer 26

Vagal innervation; anticholinergic agents

Question 27

Action fo Reglan

Answer 27

Increases LES tone, speeds gastric emptying, & lowers gastric fluid volume (by enhancing stimulation of ACh).
Antiemtic effects by blocking dopamine receptors in CTZ

Question 28

Which pts should reglan be avoided in?

Answer 28

Intestinal obstruciton, parkinsons, & pheochromocytoma (hypertensive crisis)

Question 29

ALL serotonin receptors except ____ are coupled to G proteins & affect adenylate cyclase or phospholipase C. ____ are mediated via an ion channel

Answer 29

5-HT3

Question 30

The 5-HT3 receptor mediates vomiting and is found where?

Answer 30

The GI tract & brain (area postrema)

Question 31

Serotonin is a powerful vasoconstrictor of both arterioles & veins except where?

Answer 31

In heart & skeletal muscle (vasodilation)

Question 32

_______ from released serotonin is a prominent feature of carcinoid syndrome

Answer 32

Bronchoconstriction

Question 33

Activation of _____ causes platelet aggregation

Answer 33

5-HT2

Question 34

Inhibit substance P at central & peripheral receptors. Can be used to reduce PONV as an additive with ondansetron

Answer 34

Neurokinin 1 antagonist. Aprepitant (Emend)

Question 35

Depletes substance P and inhibits pain signal transmission in surgical wounds.

Answer 35

Capsaicin (TRPV1 receptor agonist)

Question 36

Selective activation of ___ chemoreceptors by low doses of ____ stimulate hypoxic drive. What does this cause?

Answer 36

Carotid; Doxapram; produces increase in tidal colume and slight increase in RR

Question 37

Large doses of doxapram stimulate what?

Answer 37

Central respiratory centers in the medulla

Question 38

What type of opioids does Naloxone reverse?

Answer 38

Endogenous & exogenous

Question 39

Low doses of _____ reverse the side effects of epidural opioids w/o necessarily reversing the analgesia

Answer 39

IV naloxone

Question 40

The extent of sympathetic stimulation from abrupt reversal of opioid analgesia is = ?

Answer 40

The amt of opioid being reversed & speed of reversal

Question 41

Histamine _____ arterial BP and _____ heart rate and myocardial contractility

Answer 41

Reduces; increases