pharm-ponv

Question 1

who is high risk for ponv

Answer 1

1. females
2. Fatties (obese)
3. full stomach/ fatty foods
4. history of PONV
5. motion sickness, migraine
6. anxiety
7. use of post op opiates

Question 2

who is least at risk for PONV

Answer 2

smokers

Question 3

young,girls, non smoker, use of post op opiates has a___% chance of ponv

Answer 3

50%

Question 4

what procedures have higher risk?

Answer 4

1. craniotoy
2. strabismus repair
3. ENT/ T&A
4. orthopedic shoulder repair
5. certain cosmetic procedures (chest augmentation)
6. intra-abdominal
7. Laparoscopic procedures
8. heria repair (especially under spinal) .
9. GYN procedures
10. orchiopexy

Question 5

what does surgery length do to incidence of PONV

Answer 5

longer=more risk

Question 6

rank the PONV causers (in order of highest incidence to lowest)

Answer 6

1. general (gas and opiates)
2. SAB
3. regional

Question 7

what drugs increase chance of PONV

Answer 7

1. opiates (balanced anesthesia)
2. nitrous
3. ketamine
4. anticholinesterases

Question 8

1. what conditons increase PONV

2. how does the treatment of this cause PONV

Answer 8

1. pain can cause PONV

2. opiates to treat pain trigger the CRTZ in the brain and cause nausea (very important fact)

Question 9

what 5 other conditions cause PONV?

Answer 9

1. movement (thru vestibular stimulation)
2. orthostatic hypotension/dehydraton
3. hypoglycemia
4. hypoxia
5. oral intake too soon after procedure

Question 10

what are the 3 acts of vomiting?

Answer 10

nausea
retching
vomiting

Question 11

nausea

Answer 11

typically associated with decreased gastric motility and increased small intestine tone and reverse peristalsis in small intestine

Question 12

retching:

Answer 12

“dry heaves”, spasmodic respiratory movements conducted with closed glottis causing herination of abdominal esophagus into thoracid cavity due to negative pressure (due to resp effort with glottis closed)

Question 13

vomiting (phase 1)

Answer 13

when gastric and small intestinal contents are expelled
1. deep breath; glottis closes; larynx raises and opens upper esophageal sphincter; soft palate raises to close off posterior nares

Question 14

vomiting phase 2

Answer 14

diaphragm contracts sharply downward; creates neg pressure in thorax which opens esophagus and distal esophageal sphincter

Question 15

vomiting (phase 3)

Answer 15

simultaneous downward movement of diaphragm and contraction of abdomen walls squeezes the stomach elevating intragastric pressure. pylorus is closed and esophagus is open, vomit is expelled.

Question 16

who is at risk for PONV?

Answer 16

1. children and adolescents
2. women (d/t gonadotropin and estrogen)
3. history of PONV
4. non smokers
5. anxious persons/ anxiety
6. obesity (d/t larger gastrc volume, higher chance of reflux, amount of fat soluble drugs accumulated, and gall bladder/gi disease
7. Oral Intake: excess fatty foods (slows peristalsis), full stomach, currently intoxicated
8. use of post op opiates
9. history of motion sickness

Question 17

can nauser be triggered from multiple things at once?

Answer 17

yes

Question 18

what can stimulation of pharynx cause

Answer 18

N/V (ilicits emetic resopnse)

Question 19

why does car/ motion sickness occur

Answer 19

labyrinthine (vestibular) apparats and auricular branch of the tympanum of the ear detects motion stimulus from histhamine or ACH receptors

Question 20

1. what is the name of the receptors that detect overdistention and altered gastric motility which can lead to N/V?
2. In what organs of the abdomen are they located?

Answer 20

1. mechanoreceptors

2. bladder, gall bladder, uterus

Question 21

1. where are chemical stimulus detectors located in the abdomen?
2. what do they sense?

Answer 21

1. hepatic portal vein detectors

2. chemicals in the venous drainage of gut

Question 22

gastric and duodenal chemoreceptors detect what?

Answer 22

irritation from toxins such as serotonin

Question 23

what nerve sends signals regarding nausea to the brain?

Answer 23

vagus

Question 24

1. vagus nerve from gut sends signal to ___,___ & ___ receptors in brain?
2. what is the name of these areas of the brain?

Answer 24

1. histhamine, cholinergic or enkephalin receptors

2. nucleus tractus solitarius; centros of postrema and subpostrema

Question 25

what parts of the brain are affected by emotions, sights, smells or thoughts?

Answer 25

higher brain centers in the cortex and limbic system

Question 26

1. where is the chemoreceptor trigger zone (CRTZ , CTZ),

2. what does it do?

Answer 26

1. located in the postrema on the floor of the fourth ventricle of brain;
2. identify absorbed toxins, or disturbances (hypotension and metabolic acid-base changes)which is reflected as nausea and vomiting

Question 27

what must coordinate in order for vomiting to occur?

Answer 27

afferent stimuli detect the need to vomit and coordinate the response in the vomiting center in the lateral reticular formation of the brainstem close to foruth ventricle.

Question 28

what are the receptors that have a role in receiving emetic impulses?

Answer 28

histhamine, serotonin, opiod, muscarenic, and dopaminergic

Question 29

how do antihisthamines block nausea?

Answer 29

antagonizes H1 & H2

Question 30

what does H2 stimulation cause?

Answer 30

increased gastric hydrogen ion concentration

Question 31

where are H2 receptors found besides the stomach/

Answer 31

in the CNS with some in the heart

Question 32

how does a H2 blocker work?

Answer 32

blocking histhamine stimulation of H2 receptors prevents increases in cAMP (cAMP activates the proton pump of gastric parietsl cells which secrete H+ ion)