Nausea and Vomiting

Pathophysiology of motion sickness

When the inner ear labyrinth apparatus detects a body position that conflicts with sensory inputs such as vision

Pathophysiology of nausea and vomiting associated with pregnancy (NVP)

Not known but may be a combination of genetic, endocrine, and GI factors

Pathophysiology of acute/viral gastroenteritis

Inflammation of the stomach and small intestines that manifests with acute vomiting and diarrhea, often caused by rotavirus and norovirus

Pathophysiology of NV associated with overeating

Gut distension and decrease in GI motility that stimulates mechanoreceptors

Name and describe the three processes associated with NV

- Nausea (characterized by a person's subjective feeling of a need to vomit)

- Retching (involuntary rhythmic diaphragmatic and abdominal contractions prior to vomiting)

- Vomiting (rapid, forceful expulsion of GI tract contents)

Some signs and symptoms of dehydration in children

- Restlessness or irritability

- Rapid or deep breathing

- Tachycardia

- Decreased skin turgor

- Prolonged capillary refill in the fingertip after release of a gentle squeeze

Criteria for minimal dehydration in kids

<3% body weight loss

Criteria for mild-moderate dehydration in kids

3-9% body weight loss

Criteria for severe dehydration in kids

>9% body weight loss

FDA-approved pharmacologic therapy for motion sickness

Meclizine, dimenhydrinate, diphenhydramine

Off-label pharmacologic therapy for motion sickness

Doxylamine

Pharmacologic therapy for nausea associated with food or beverages

Antacids, H2RAs, Bismuth Subsalicylate, Phosphorated Carbohydrate Solution

Nonpharmacological recommendations for NVP

- Eating frequent small meals

- Avoiding spicy or fatty foods

- Take a prenatal multivitamin one month before planned conception

Treatment considerations for NV for geriatric population

- Do not use antihistamines (anticholinergic effect)

- PCS can be used

- Use nonpharm options such as avoiding trigger foods and scents

Treatment considerations for NV for lactation

- Do not use antihistamines

- BSS is barely absorbed by the infant but alternatives are preferred

- Little evidence supports safety of ginger

Treatment considerations for NV for children

- Do not use antihistamines or BSS

- Oral rehydration therapy appropriate for mild-moderate dehydration

Physical assessments for patients presenting with NV

- General appearance

- Mental status

- Vital signs

- Volume status

- Presence and severity of any abdominal pain

How long before follow-up

Within 24 hours

NV Treatment Goals

- Provide symptomatic relief

- Identify and correct the underlying cause

- Prevent and correct complications

- Prevent future occurrences

Adult exclusion criteria: Suspected food poisoning that does not clear up after ____________

24 hours

Adult exclusion criteria: Severe abdominal pain in the ____________________ quadrants

Middle or right lower quadrants (could be appendicitis or bowel obstruction)

Adult exclusion criteria: Severe _____________ quadrant pain, especially after eating fatty foods

Right upper quadrant (could be cholecystitis or pancreatitis)

Adult exclusion criteria: _________ skin or eye discoloration and ___________ urine

Yellow skin and dark urine (could be hepatitis)

Adult exclusion criteria: Persons with ____________________ (list medical conditions)

Glaucoma, BPH, bronchitis, emphysema, or asthma (adverse reactions to OTC antiemetics)

Adult exclusion criteria: N/V caused by ________________ (list therapies or disorders)

Cancer chemotherapy, radiation therapy, serious metabolic disorders, CNS, GI, or endocrine disorders

Adult exclusion criteria: Drug-induced N/V: adverse effects of drugs used therapeutically such as__________________

Opioids, NSAIDs, antibiotics, estrogens

Adult exclusion criteria: Drug-induced N/V: toxic doses of drugs used therapeutically such as________________

Digoxin, theophylline, lithium, ethanol

Adult exclusion criteria: Chronic disease-induced N/V: ____________________

Gastroparesis with diabetes, diabetic ketoacidosis or hyperosmolar hyperglycemic state with diabetes, GERD

Other adult exclusion criteria

- Urine ketones/high blood glucose with signs of dehydration in diabetic patients (could be DKA or HHS)

- N/V with fever or diarrhea (could be infectious disease)

- Blood in the vomitus (could be ulcers, esophageal tears, severe nosebleed)

- Stiff neck and sensitivity to normal light (could be meningitis)

- Head injury with N/V, blurry vision, numbness, and tingling

- Pregnancy (severe symptoms) or breastfeeding

- Psychogenic-induced N/V, bulimia, anorexia

Pediatric exclusion criteria: Age < ___________, weight < _________, vomited clear fluids ________ times, watery diarrhea

6 months, 17.6 lb (8 kg), 3 times

Pediatric exclusion criteria: > ___________% reduction in body weight

9%

Pediatric exclusion criteria: Lack of urination in the past _______________ hours

8-12 hours

Pediatric exclusion criteria: Age < ______________ with ___________ large diarrhea stools

1 month, 3 large diarrhea stools (could be sepsis)

Pediatric exclusion criteria: Age < ______________ with vomiting __________ times

12 weeks, 2 times (could be GI obstruction, pyloric stenosis)

Pediatric exclusion criteria: Age < _______________ with _____________ diarrhea stools in the last _____________ hours

12 weeks, 8 stools, 8 hours

Pediatric exclusion criteria: Severe headache that persists for _______________ (time)

more than 2 hours (could be meningitis or first migraine)

Pediatric exclusion criteria: Child has concomitant disorder that may complicate management such as ____________

Diabetes, CNS disease, hernia

Other pediatric exclusion criteria

- Signs of severe dehydration present

- Caregiver is unable/unwilling to manage child's N/V at home

- N/V accompanied by stiff neck, refusal to drink liquids, lethargy, unusually sleepy, listless, crying, vomiting with each feeding, projectile vomiting for > 8 hours, colored fluid in vomit

- Vomiting with head or abdominal injury

- Suspected poisoning

- Vomiting occurs with recurrent, severe, acute abdominal pain (especially if abdomen is swollen)

Nonpharmacological options to prevent motion sickness

- Avoid reading during travel

- Focus line of vision straight ahead

- Avoid excess food/alcohol while traveling

- Stay where motion is least experienced (front of car, near wings of airplane)

- Avoid strong odors

- Drive vehicle if possible

Prevention of N/V in pregnancy: take prenatal vitamin ___________________ (when)

1 month prior to conception

Prevention of N/V in pregnancy: Eat small meals every ____________ hours to avoid a full stomach

1-2 hours

Prevention of N/V in pregnancy: Morning routine

- Before getting out of bed, eat several dry crackers and relax in bed for 10-15 minutes

- Get out of bed very slowly and do not make any sudden movements

- Before eating breakfast, nibble on dry toast and crackers

Prevention of N/V in pregnancy: Other strategies

- Make sure there is plenty of fresh air in the area where meals are prepared and eaten

- Avoid areas of excessive heat or humidity

- When nauseated, take small sips of carbonated beverages or fruit juices

- Avoid greasy, fatty, spicy, or acidic foods

- Avoid sensory stimuli such as odors, noises, or flickering lights

- Avoid iron-containing supplements

- Eat dry, bland, and high-protein foods

Antiemetic antihistamine MOA

Compete with histamine at central and peripheral H1 receptors, preventing histamine-receptor interactions and subsequent mediator release

Examples of antiemetic antihistamines

- Meclizine

- Diphenhydramine

- Doxylamine

Meclizine and diphenhydramine indications

- Prevention and treatment of nausea, vomiting, or dizziness associated with motion sickness

- When used for motion sickness, take at least 30-60 minutes before departure and continue throughout travel

Doxylamine indications

First line for N/V during pregnancy

Antiemetic antihistamine side effects

- Dry mouth

- Confusion

- Dizziness

- Tremors

- Constipation

- Drowsiness

Rank the antiemetic antihistamines from most drowsy to least drowsy

- Diphenhydramine > Doxylamine > Meclizine

Antiemetic antihistamine cautions

- Caution in patients with respiratory conditions, angle-closure glaucoma, BPH due to urinary retention

Antiemetic antihistamine contraindications

- Concomitant use with other CNS depressants (alcohol, hypnotics, sedatives)

- Older adults

Phosphorated carbohydrate solution (PCS) MOA

Hyperosmolar solution that decreases smooth muscle contraction and delay gastric emptying time, which relieves N/V

PCS indications

Nausea associated with food or beverages

PCS side effects

Stomach pain, diarrhea

PCS cautions

Caution in diabetic patients

PCS contraindications

Hereditary fructose intolerance

Bismuth subsalicylate MOA

- Forms bismuth oxychloride and salicylic acid in presence of gastric acid

- Has antibacterial and antisecretory actions

- Binds enterotoxins

Bismuth subsalicylate indications

Nausea associated with consumption or nonulcer dyspepsia

Bismuth subsalicylate side effects

Harmless black staining of stool and darkening of the tongue

Bismuth subsalicylate contraindications

- Avoid in children < 12 years old

- May interfere with radiographic intestinal studies

Ginger indication

- Nausea related to pregnancy, motion sickness, or surgery

Ginger evidence for pregnancy

- May be superior to placebo in preventing NVP

- May be as effective as pyridoxine

- Risk to pregnancy unknown (insufficient data)

Ginger side effects

- Mild adverse GI effects (heartburn, diarrhea, mouth irritation)

- Possible anticoagulant and hypotensive effects

Pyridoxine indications

NVP

Pyridoxine evidence for NVP

First line for NVP with or without doxylamine

Ginger evidence for motion sickness

No strong available data

Ginger evidence for nausea from surgery

At least 1 gram of ginger was effective

Pyridoxine risks

Excreted in breast milk and high doses may inhibit prolactin secretion

Acupressure indications

NVP and motion sickness

How to perform acupressure

Apply pressure 3 finger widths from the middle crease of wrist

Evidence for acupressure

- May be more effective for preventing postoperative N/V than NVP

- Dosing had mixed results for efficacy

Acupressure risks

Do not use acupressure product in patients with a pacemaker

Cannabinoids indication

N/V

Cannabinoids evidence

- Lacking studies on safety and quality of CBD

Cannabinoids risks

- Potential liver injury, drug interactions, and male reproductive toxicity

- Products containing CBD are not standardized

Pros of ORS powder

75 mEq/L of sodium can reduce duration of diarrhea, stool output, and vomiting

Cons of ORS powder

Improper mixing for children can lead to electrolyte complications and injury

Pros of pre-mixed ORS solution

Preferred over powder for children (safe and convenient)

Cons of pre-mixed ORS solution

May be more expensive

Pros of cereal-based ORS

Reduces stool volume in cholera

Cons of cereal-based ORS

May not alter stool volume in children with non-cholera acute diarrhea

How much ORS to give child under 10 kg experiencing minimal weight loss

60-120 mL after each vomiting/diarrhea episode

How much ORS to give child over 10 kg experiencing minimal weight loss

120-240 mL after each vomiting/diarrhea episode

How much ORS to give child experiencing mild-moderate weight loss

50-100 mL/kg over 3-4 hours and 10 mL/kg for each vomiting/diarrhea episode

How much ORS to give to children over 6 and adults for minimal weight loss

Increase fluids in regular diet

How much ORS to give to children over 6 and adults for mild-moderate weight loss

Begin ORS at 2-4 L over 3 hours and replace ongoing losses

How long after vomiting should you wait before giving ORS?

10 minutes

Give young children _____ mL of ORS every ________ minutes

5 mL every 5 minutes

Give older children and adults _______ mL of ORS every _________ minutes

15 mL every 5 minutes