Nausea and Vomiting Flashcards
What is nausea?
Unpleasant awareness of the urge to vomit
Proceeded or accompanied by increased perspiration, salivation, tachycardia, increased respiration rate, lack of appetite and headache
What is vomiting?
Emesis
Forceful expulsion of stomach contents
Acute vs delayed (acute is within 24 hours, delayed is after 24 hours)
Breakthrough (when you’re taking something and you’re still vomiting)
What is retching?
Dry heaves
Strong, involuntary and unsuccessful effort to vomit
Describe the pathophysiology of nausea and vomiting
The area that coordinates vomiting is called the vomiting centre is called the vomiting centre
The vomiting centre receives the integrates afferent impulses and stimuli
The vomiting centre then sends efferent impulses to salivation centre, respiratory centre, pharyngeal , GI and abdominal muscles
What are the neurotransmitters and receptors involved in nausea and vomiting?
Dopamine Histaminic Acetylcholine Vasopressin Serotonin Unknown neurotransmitters
What are the centre involved with nausea and vomiting?
Chemoreceptor trigger zone (CTZ)
Cerebral cortex and limbic system
Vestibular function disturbances
Sensory receptors in GI tract
What is nausea and vomiting associated with?
It is a symptom of over 75 different conditions
Nausea and vomiting is associated with motion sickness, post chemotherapy nausea and vomiting, pregnancy-associated nausea and vomiting, post operative nausea and vomiting, medication-induced nausea and vomiting
What causes visceral afferent stimulation?
Mechanical obstruction Motility disorders Peritoneal irritation Infections Topical GI irritants Other
What are CNS disorders that can cause nausea and vomiting?
Vestibular disorders Increased intracranial pressure Infections Psychogenic Other
What causes CTZ irritation?
Initiated or withdrawn drugs
Systemic disorders
What needs to be considered while doing a differential diagnosis of motion sickness?
Vestibular disease Gastroenteritis Metabolic disorders Toxin exposures Mountain sickness
What are complications due to vomiting?
Dehydration Aspiration Malnutrition Electrolyte imbalance Acid-base imbalance Dental caries Esophageal rupture
What are signs and symptoms of dehydration in adults?
Increased third
Decreased urination
Feeling weak or light-headed
Dry mouth/tongue
What are signs and symptoms of dehydration in children?
Dry mouth and tongue
Sunken and/or dry eyes
Sunken fontanelle (soft spot)
Decreased urine output (i.e., dry diapers for several hours)
Dark urine
Fast heartbeat
Thirst (drinks extremely eagerly)
Absence of tears when crying
Decreased skin turgor (increased axillary skin folds, “doughy” skin (may indicate hypernatremia), when pinched, skin returns to normal very slowly)
Unusual listless, sleepiness, decreased alertness or tiredness (body if “floppy”, lightheadedness when sitting/standing, difficulty in waking child up)
Weight loss
Describe weight loss as a sign/symptom of dehydration in children
Noticeable decrease in “tummy size”
Clothes/diapers fit loosely
Less than 3% body weight loss = minimal/no dehydration
3-9% body weight loss = mild/moderate dehydration
Over 9% body weight loss = severe dehydration
How can nausea and vomiting be classified?
Simple
Complex
Describe simple nausea and vomiting
Occasional episodes, self-limiting or relieved by minimal use of an anti-emetic
Consequences are mild
Not related to administration or exposure to noxious agents
Describe complex nausea and vomiting
Symptoms are not adequately or readily relieved by single anti-emetic
Consequences are severe
Caused by noxious agents or psychogenic events
Describe motion sickness
Very common condition; 58% of children experience car-sickness and up to 100% of travellers on ships experience seasickness
Greatest incidence occurs from ages 3 to 12 (children under 2 are immune to motion sickness)
Females are more prone than males (especially during pregnancy and menstruation)
What are the signs and symptoms of motion sickness?
Vomiting Malaise/apathy Yawning Feeling restless Feeling warm Drowsiness Belching Excessive salivation Flatulence Breaking into a cold sweat Headaches Migraines Loss of appetite
What are risk factors for motion sickness?
Type of travel (boat > air > car > train) Stimulus intensity and frequency Duration of directional change Smoke Poor ventilation Individual predisposition
What are the goals of treatment of nausea and vomiting?
Eliminate or reduce symptoms of nausea
Prevent or reduce the frequency of vomiting
Prevent complications of nausea and vomiting
What are treatment approaches for motion sickness?
Counsel on non-drug methods
Recommend anti-emetic to prevent or treat if needed
Treat children in the same manner as adults (watch for age restrictions of medications)
Rehydrate patient if vomiting occurs or patient is dehydrated
What are pharmacological treatments based on?
Availability (OTC vs Rx) Previous response Route of administration Cost Side effects Patient preference
What are the non-prescription therapies available for motion sickness?
Dimenhydrinate (DMH; Gravol)
Diphenhydramine (Benadryl)
Scopolamine (Transderm V)
Ginger root (zingiber officinale Roscoe; Gravol - Natural Source)