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Flashcards in GI System Deck (48):
1

For surgical patients, is there ever a chance for zero PONV

No

2

Define retching

rhythmic action of respiratory muscles preceding vomiting

3

Define Nausea

SUBJECTIVE personal patient experience with or without associated vomiting

4

The Vomiting Center is located where

Lateral reticular formation within the medulla oblongata

5

What two regions located near the vomiting center, once stimulated will initiate vomiting

Nucleus solitarius

Chemoreceptor Trigger Zone (located in the areas postrema near the bottom of the 4th ventricle)

6

What factors stimulate the vomitng center

Peripheral stimulation (sensory afferents of vagal nerve to VC)

CNS (directly relay to CTZ, AP, and NTS)

Chemicals in the CNS/Blood (directly stimulate VC)

7

What are the five CNS areas that are located near the VC and what are the physiological reactions associated with N/V

Balance center (motion sickness)
Vasomotor center (diaphoresis, pallor, tachycardia, cardiac dysrhythmias)
Salivation center
Respiratory center (tachypnea)
Bulbar controls (cerebellum, medulla, and pons)

8

True/False
Although the CTZ, AP, and NTS contain receptors for vomiting, the vomiting reflex is INITIATED from within the vomiting center

True

9

What receptor population live withing the CTZ

Dopamine (D2)
Opioid
Enkephalin

10

What receptor population live within the AP

Dopamine
Opioid
Serotonin (5-HT)

11

What receptro population live within the NTS

Histamine
Enkephalin
Muscarinic

12

What physiologic state is a potent emetic stimulus

Blood in the stomach

13

Between 2-14, incidence of PONV increases or decreases

increases

14

After 14 yoa, incidence of PONV increases or decreases

decreases

15

What anesthetic agents increase PONV

Neostigmine
Etomidate
Methohexital
Opioids
Ketamine
NITROUS OXIDE
All HALOGENATD AGENTS

16

What scoring system is used when a patient is at increased risk for PONV

Apfel scoring system

17

What four risk factors does the apfel scoring system assess

PONV
Use of Postop opioids
Female gender
Nonsmoker

18

If a patient has zero factors on apfel, what is the incidence of PONV

10%

19

If a patient has all four factors on apfel, what is the incidence of PONV

79%

20

If a paitent has 2 factors on apfel, what is the incidence of PONV

39%

*up/down by 20% from here

21

* What receptors can I stimulate to decrease PONV

Muscarinic (M3, M5)
Dopaminergic (D2)
Histamine (H1)
Serotonin (5-HT)

22

What antimuscarinic drug does not cross the bbb and therefore, cannot be used to treat vomiting

Glycopyrollate

23

Sucralfate is classified as an

anti-ulcer agent

24

"prazoles" are

proton pump inhibitors

25

Inhibition of acid production continues how long after administration of prazoles

up to 72 hours

*may not need to give to patient if taken within this time period prior to surgery

26

Misoprostol is used in OB to

induce labor

27

Misoprostal is contraindicated

during pregnancy

28

What is the MOA of metaclopramide

increases LES spincter tone
increases gastric emptying
decreases gastric volume

*centrally acts as a dopaminergic antagonist resulting in antiemetic properties

29

What are the precautions associated with metaclopramide

Contraindicated in intestinal obstruction or pheochromocytoma

Avoid in patient's with parkinson's

May cause tardive dyskinesia

30

Cisapride is a

prokinetic

31

What are the two anti-emetics discussed in lecture

Metoclopramide
Droperidol (potent)

32

True/false
Droperidol is a neuroleptic tranquilizer

true

33

Peripherally, droperidol acts as a

alpha-adrenergic blocker
*decreases ABP

34

Droperidol has what effect on patient's with pheochromocytoma

stimulate the release of catecholamines from the adrenal medulla precipitating a HTN crisis

35

What effect does Droperidol have on cerebral blood flow/ICP

decreases

*Does not decrease CMRO2, problem for pts with CVS disease

36

Droperidol has antidopaminergic activity and therefore can precipitate

extrapyramidal reactions

*dont use in patient's with parkinsons

37

What drugs is countered by droperidol

dopamine
central a-adrenergic agonists

38

What is the "Black Box" warning on droperidol

may cause QT prolongation/torsades de points leading to potentially fatal rhthyms

* use only patients refractory to other anti-emetics. Must monitor EKG

39

Ondansetron works on what receptor type

selective 5-HT3

*does not effect alpha, dopamine, or histamine receptors

40

The phenothiazine hydroxyzine should ONLY be given

IM

*never IV

41

Phenothizaines examples include promethazine, prochlorperazine, and hydroxyzine and involve many reactions including:

sedative-tranquilizer
antiemetic
antihistamine/antipuritic
adrenolytic
anticholinergic
extrapyramidal activity
Potentiator of anesthetics

42

Phenothiazines may cause what syndrome

Neuroleptic Malignant Syndrome

*Fever, muscle ridgidity, AMS, autonomic dysfunction, leukocytosis, elevated CPK

43

Excess Fe is stored as

Ferritin

44

What is the ONLY clinical indication for the use of iron

Treating iron deficiency anemia

45

Iron sodium gluconate complex is given

ONLY IV

46

What is the Gold standard treatment for acute iron toxicity

Deferoxamine

*activated charcoal DOES NOT work

47

What is the central atom in vitamin b12

COBALT

48

Without vitamin b12, what two ESSENTIAL enzymatic rxn couldn't occur

methyltetrahydrofolate to tetrahydrofolate (folate)

methylmalonyl-CoA to succinyl-CoA