Ch. 19 - N/V

Question 1

N/V

Answer 1

• Can arise from a variety of sources including pregnancy, motion sickness, viral gastroenteritis, “upset stomach”
• No accurate epidemiology
• Nausea is more common in women and occurs more frequently in pregnancy/menstruation (50-80%)
• Hyperemesis gravidarum occurs in ~1% of preggo and requires hydration and hospitalization
• Motion sickness severity is hard to quanitfy due to individual variability/susceptibility
• Other treatable source arises from gastroenteritis which causes inflammation of stomach/small intestine which leads to vomiting and diarrhea
• Most commonly caused by rotavirus and norovirus in autumn/winter and is usually self limiting
• Rotavirus commonly vaccinated against as a child and noro usually arises from a foodborne illness

Question 2

N/V Pathophysiology

Answer 2

• Involves CNS and GI tract
• Vomiting center in medulla oblongata includes CTZ, vestibular apparatus, cerebral cortex, and visceral GI treat afferent nerves
• CTZ goes outside BBB so it is stimulated by spinal fluid and bloodstream
• Vestibular apparatus is a bony labyrinth that detects motion and body position
• Serotonin, DA, Histamine type 1, ACh, and opioid receptors act to stimulate vomiting
• Complicated secondary defense to secondary mechanisms
• Coordination of muscle tissues and muscles like abdominal muscles, diaphragm, laryngeal tissues, pharyngeal tissues, epiglottis, soft palette, fundus, and stomach muscles
• Motion sickness: stimulated by labyrinth apparatus; easier to avoid than treat, activated by ACh and histamine
• Pregnancy - not sure which receptors are involved but believed to be multi-factorial, antiemetics may be used on a benefit:risk basis
• Viral gastroenteritis - dopamine, serotonin, ACh, histamine; target these receptors to treat

Question 3

N/V Clinical Presentation

Answer 3

1. Nausea - feeling the need to vomit
2. Retching - involuntary rhythmic diaphragm and stomach muscle contraction
3. Vomiting - rapid, forceful expulsion of GI contents
   - Usually self-limiting
   - Acute complications: dehydration, esophageal tears, aspiration, malnutrition, electrolyte imbalance, herniation
   - Dehydration and electrolyte imbalances are the BIG concern, especially in children (send to PCP)
   - Signs/Symptoms of dehydration: dry mouth, decreased skin turgor, excessive thirst, decreased urination, dizziness, decreased BP
   - If these signs/symptoms are seen, send to PCP

Question 4

N/V Treatment Goals

Answer 4

1. Provide symptomatic relief
2. Identify/correct underlying cause
3. Prevent/correct complications
4. Prevent future occurrences

Question 5

N/V General Treatment Approach

Answer 5

• Usually self-limiting so be sure to evaluate patient well to determine if self-treatment is necessary
• Severe cases: dehydration/electrolyte imbalance requires hospitalization and medical evaluation
• ORS: oral rehydration salts that can contain NaCl, K+, glucose, or dextrose to return loss of electrolytes or fluids

Question 6

N/V Nonpharmocologic

Answer 6

• ORS: for dehydration with N/V
• Mix 1/2 a teaspoon of salt, 6 teaspoons of sugar, and 1 L of water; glucose based so no K+ (supplement with bananas or OJ), better at rehydrating than water alone
• Don’t use products with too much sugar since this can worsen diarrhea
• Children < 10 kg: 60-120 mL of solution; >10 kg: 120-240 mL of solution
• Mild-Moderate dehydration: 50-100 mL/kg over 3-4 hours
• Severe dehydration: ER for IV transfusion
• Adults should replace 30-50% of fluid loss in 24 hours but can base fluid need from thirst
• 5 mL/5 minutes after vomiting for kids, 15 mL/5 minutes for adults (only after actively vomiting)
• Use preventative measures for motion sickness
• Nonpharm is better for preggo and BF

Question 7

Preventions for Motion Sickness

Answer 7

• Avoid reading while traveling
• Avoid excess food and alcohol while traveling
• Sit where motion is minimized: car - front seat, driving, plane - over wings, boat - mid-ship, above deck
• Avoid strong odors

Question 8

Motion Sickness Pharmacologic

Answer 8

• Antihistamines - safe and effective, well tolerated
• Meclizine only non-Rx approved for N/V
• Diphenhydramine and doxylamine are off-label uses
• Use with caution with asthmatics, bronchitis, emphysema, closed-angle glaucoma, and BPH
• SE: dry mouth confusion, dizziness, tremors, constipation, drowsiness (most common SE)
• Don’t use with alcohol, hynotics, and sedatives
• Meclizine should be less sedating than diphen/doxy
• If using diphenhydramine, don’t pair with medications metabolized by CYP2D6

Question 9

Overindulgence Pharmacologic

Answer 9

-N/V can occur with overeating or eating disagreeable foods
-Can cause heartburn, indigestion, and upset stomach
-Antacids and H2RA are good for indigestion and sour stomach
-Prolonged nausea/bloating may indicate dysmobility which requires pharmacologic treatment
Bismuth salicylate - some benefit for consumption nausea - approved for nausea, heartburn, and fullness
-Phosphorylated carbonhydrate solution (PCS) is also good for nausea: Hyperosmolar that acts on stomach wall to decrease smooth wall contraction and delay gastric emptying
-Don’t substitute with soda, too much sugar
-PCS, adults: 15-30 mL/15 minutes until distress subsides
-PCS, kids (2-12 y.o.): 5-10 mL/15 minute
-Don’t dilute with other fluids immediately before or after
-ASE: stomach pain, diarrhea
-Caution in those with diabetes and fructose intolerance

Question 10

N/V Product Selection Guidelines

Answer 10

• Consider medical conditions and status

- Also consider lifestyle, medication use, frequency of N/V, preferences, and allergies when selecting

Question 11

Preggo N/V

Answer 11

• NONPHARM is primary
• No spicy or fatty foods (at least decrease)
• Bland carbs can help in the morning
• Use multivitamin at conception to decrease NVP
• Pyridoxine: good at 1.9mg/day, can cross breast milk and decrease its production (1st line)
• May be equally effective to ginger

Question 12

Elderly N/V

Answer 12

• Avoid antihistamines if possible
• PCS can be used in nondiabetics
• Accupuncture/acupressure bandages shouldn’t be used on those with pacemakers
• Also use nonpharm. techniques like avoiding trigger foods and scents

Question 13

Lactation N/V

Answer 13

• Avoid antihistamines
• Bismuth subsalicylate should be used cautiously since it’s excreted slowly in breast milk
• Little evidence on ginger’s safety

Question 14

Children N/V

Answer 14

• Increased risk of dehydration complications
• Increased risk of serious causes like GERD and obstructions
• Mild dehydration: <3% of body weight loss, Moderate: 3-9%, Severe: >9%
• Treat mild to moderate dehydration with rehydration
• Don’t use antihistamines or bismuth

Question 15

Ginger -N/V

Answer 15

• Possible complementary therapy of N/V
• Used with nausea in preggo, motion sickness, and surgery
• Superior to placebo with no higher risks to fetus
• May cause hypotensive/anticoagulant effects and can further upset GI treat
• 250 mg 4x a day for nausea
• Equally effective as pyridoxine
• Don’t exceed 1 g per day

Question 16

Pyridoxine (Vitamin B6) -N/V

Answer 16

• Water soluble vitamin important for metabolic fxns
• Dosing: 10-25 mg TID
• Generally well tolerated, long use of large doses causes SE
• Studies overall show effectiveness and may be used off-label for preggo and severe N/V

Question 17

Acupressure -N/V

Answer 17

-Pressure on P6 on either wrist, can use prn

Question 18

Aromatherapy - N/V

Answer 18

• Peppermint oil for N/V, no reliable evidence
• Isopropyl alcohol more effective than placebo but less effective than antiemetic medications
• Overall, lacking evidence

Question 19

N/V Summary

Answer 19

• Antihistamines: motion sickness (minus excluded pops)
• PCS: overeating, also antacids, H2RAs, and bismuth
• ORS: important for dehydration, give smaller, frequent doses to those who are consistently vomiting, safe for everyone
• Pyroxidine: first line for NVP
• Ginger and acupressure more efficacious than aromatherapy

Question 20

N/V Assessment

Answer 20

• Evaluate general appearance, mental status, volume status, and abdominal pain
• Take vital signs and concurrent symptoms
• If N/V from toxin, especially in kids, see medical professional
• If severe nausea/diarrhea for several hours in kids or >48 hours in adults, assess for dehydration
• If dehydrated or malnourished, send for medical eval.
• Ask about other medications taking or used for N/V

Question 21

N/V Counseling

Answer 21

• Identify and correct cause
• Avoid overeating or exacerbation of motion sickness
• Symptomatic treatment usually utilized
• Proper use, ASE, CI, and when to see doctor

Question 22

N/V Evaluation

Answer 22

• Follow up within 24 hours
• Usually done best by phone call
• Determine if N/V has decreased or ceased
• Determine if residual, serious symptoms remain
• Prolonged N/V (24-48 hours) or worsening/changing symptoms should be referred for medical evaluation
• Check for further counseling opportunities

Question 23

N/V Adult Exclusions

Answer 23

• Ketones + Dehydration in diabetic patients
• Food poisoning that hasn’t cleared up in 24 hours
• Severe abdominal pain in mid/right lower quadrant
• Fever or diarrhea
• Severe upper right quad. pain after eating
• Blood in vomit
• Yellow skin or eyes
• Stiff neck with or w/o headache
• Head injury
• Glaucoma, BPH, bronchitis, emphysema, asthma
• Pregnancy or BF
• N/V from chemo or other disorders
• Drug-induced N/V
• Anorexic, bulimic

Question 24

N/V Children Exclusions

Answer 24

• Signs of severe dehydration
• Unwilling/unable to care for N/V at home
• Stiff neck, <6 mo. vomiting clear fluid 3x
• Refusal to drink fluid
• Lack of urination over 8-12 hours
• Lethargic, listless, crying
• Vomiting with each feeding
• Repeated projectile vomit over 8+ hours
• Vomit contains red, black, or green fluid
• Diarrhea, distended abdomen, fever, or severe headache
• Suspected poisoning
• Following head or stomach injury
• <1 mo. with 3 large diarrhea stools
• <12 weeks with fever
• <12 weeks and vomiting 2x
• <1 year with 8 diarrhea stools in 8 hours
• Recurrent, severe, acute stomach pain
• High risk children (diabetic, CNS, hernia)

Question 25

NVP Prevention

Answer 25

- Taking multivitamin for 3 months prior to conception - Eat several dry crackers before getting out of bed and relax for 10-15 minutes - Get out of bed slowly and don't make sudden movements - Nibble on dry toast or crackers before breakfast - Fresh air in area where meals are prepared and served - Eat small meals every 1-2 hours - Avoid areas with excessive heat or humidity - When nauseous, small sips of carbonated beverages or fruit juices - Avoid greasy or fatty foods as well as spicy or acidic foods - Avoid triggers - Avoid iron-containing supplements - Eat dry, bland, high-protein foods