Ch. 19 - N/V Flashcards
1
Q
N/V
A
- 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
2
Q
N/V Pathophysiology
A
- 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
3
Q
N/V Clinical Presentation
A
- Nausea - feeling the need to vomit
- Retching - involuntary rhythmic diaphragm and stomach muscle contraction
- 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
4
Q
N/V Treatment Goals
A
- Provide symptomatic relief
- Identify/correct underlying cause
- Prevent/correct complications
- Prevent future occurrences
5
Q
N/V General Treatment Approach
A
- 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
6
Q
N/V Nonpharmocologic
A
- 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
7
Q
Preventions for Motion Sickness
A
- 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
8
Q
Motion Sickness Pharmacologic
A
- 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
9
Q
Overindulgence Pharmacologic
A
-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
10
Q
N/V Product Selection Guidelines
A
- Consider medical conditions and status
- Also consider lifestyle, medication use, frequency of N/V, preferences, and allergies when selecting
11
Q
Preggo N/V
A
- 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
12
Q
Elderly N/V
A
- 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
13
Q
Lactation N/V
A
- Avoid antihistamines
- Bismuth subsalicylate should be used cautiously since it’s excreted slowly in breast milk
- Little evidence on ginger’s safety
14
Q
Children N/V
A
- 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
15
Q
Ginger -N/V
A
- 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
