9 - Nausea & Vomiting Flashcards
(41 cards)
What is retching?
Strong, involuntary and unsuccessful effort to vomit
What is the area of the brain that coordinates vomiting and what does it do?
- Vomiting center
- Receives and integrates afferent impulses and stimuli and then sends efferent impulses to salivation centre, respiratory centre, pharyngeal, GI, and abdominal muscles
What are the NTs and receptors involved in vomiting?
- Dopamine
- Histamine
- Acetylcholine
- Vasopressin
- Serotonin
What is important pathophysiology for motion sickness?
Vestibular function disturbances
What is mismatched vestibular function?
When what the body is expecting and what the body actually feels don’t match up
What are some causes of nausea and vomiting?
- Visceral afferent stimulation (mechanical obstruction, motility disorders, peritoneal irritation, infections)
- CNS disorders (increased intracranial pressure, infections, psychogenic)
- Irritation of chemoreceptor trigger zone (initiated or withdrawn drugs, systemic disorders)
What are some complications of vomiting?
- Dehydration
- Aspiration
- Malnutrition
- Electrolyte or acid-base imbalance
- Dental caries
- Esophageal rupture
What are signs and symptoms of dehydration in adults?
- Increased thirst
- Decreased urination
- Feeling weak or light-headed
- Dry mouth/tongue
What are signs and symptoms of dehydration in children?
- Dry mouth and tongue
- Decreased urine output
- Dark urine
- Increased heartbeat
- Decreased skin turgor (when pinched, skin returns to normal very slowly)
- Weight loss
What are the 2 classifications of nausea and vomiting and what are symptoms of each?
1) Simple
- Occasional episodes
- Self-limiting or relieved by minimal use of anti-emetic
- Not related to administration/exposure to noxious agent
2) Complex
- Symptoms not adequately or readily relieved by single anti-emetic
- Consequences severe
- Caused by noxious agents or psychogenic events
When is the greatest incidence of motion sickness?
3-12 years old (under 2 are immune)
What are risk factors for motion sickness?
- Type of travel (boat worst and train least)
- Stimulus intensity and frequency
- Duration of directional change
- Poor ventilation
- Individual predisposition
What are the goals of therapy for nausea and vomiting?
- Eliminate or decrease symptoms of nausea
- Prevent or decrease frequency of vomiting
- Prevent complications of nausea and vomiting
What is the mechanism of action of dimenhydrinate and diphenhydramine?
- Blocks ACH and H1 receptors centrally
- Acts on H1 receptors in vomiting centre
What is the dosing of dimenhydrinate for treatment of motion sickness in adults?
50-100 mg every 4 hours if necessary to a maximum of 400 mg per day
What are side effects to dimenhydrinate and diphenhydramine?
- Sedation, blurred vision
- Dry mouth
- Constipation, urinary retention
- Paradoxical excitation in children
What is the mechanism of action of scopolamine?
Blocks ACh in vestibular apparatus
What is scopolamine used for?
Prevention of motion sickness
What is the dosing for scopolamine?
- Apply 1 patch to dry hairless area of post-auricular skin
- Should be applied 4-12 hours before departure
- Disc should not be left on more than 72 hours and can reapply to other eye
- Treatment should not exceed 6 days
Is scopolamine recommended in children?
No
Is ginger recommended in children?
Only over 12 years old
What are side effects to scopolamine?
- Sedation, dizziness, blurred vision
- Constipation
- Rash
- Elderly at increased risk of CNS effects
What is the dosing for ginger root?
- Prevention – 2 tablets/lozenges 30 minutes before departure
- Treatment – 2 tablets/lozenges 1-3 times per day (do not exceed 6 per day)
What is a side effect to ginger root?
Can exacerbate symptoms in patients w/ acute inflammatory skin diseases and can cause contact dermatitis
