Nausea And Vomiting Flashcards
Vomiting
Forceful expulsion of gastric contents from the mouth
What physical actions create vomiting
Powerful sustained contraction of abdo muscles
Diapragm descent
Opening of LOS
Gastric Retropulsion
Which muscles contract during vomiting
Abdominal muscles
Diapragm
Nausea
Unpleasant sensation and awareness of urge to vomit
What are effects of prolonged nausea
Dehydration
Anorexia
Broken ribs - repetitive vomiting
Refusal of medications
Cyclic vomiting syndrome
Rapid fire Projectile vomiting lasting a few hrs to several days abt 10 times a yr followed by asymptomatic periods
Gastroparesis symptoms
Early satiety after eating
Postprandial fullness
Nausea
Vomiting
Belching
Bloating
What can cause nausea and vomiting
Chemo
Radiotherapy
GI disease
Infections
Severe pain
Intra cranial disease
Labyrinthine/vestibular disorder
Pregnancy
Psychological
Migraine
Circulatory syncope
Exogenous emetic substances
Which nucleus receives sensory inputs and coordinates motor outputs for vomiting
Nucleus tractus solitarius
What nuclei cause vomiting
Nucleus ambiguus
Ventral resp group of neurones
Dorsal motor vagal nucleus
Which type of drugs are commonly used for motion sickness
Muscarinic receptor agonists
How does diphenhydramine work
H1 receptor antagonist
M2 receptor antagonist
What molecule is diphenhydramine usually combined with and why
8-chlorotheophylline -> dramamine
Counteract drowsiness
What is a side effect of diphenhydramine
Drowsiness
What type of drug is cyclizine
H1 receptor antagonist
What can cyclizine be used to treat
Vertigo
Motion sickness
Labyrinthine disorders
What type of drugs are phenothiazines, metoclopramide, and domperidone
Dopamine d2 receptor antagonists
Side effects of D2 receptor antagonists
Pseudoparkinsonism
Acute distonia
Akathisia
Tardive dyskinesia
What is the only drug to treat gastroparesis
Metoclopramide
What is metoclopramide used to treat
Post operative care
Gastritis
Migraine
Dysmenorrhea
Drug/treatment induced emesis inc anaesthesia radio and chemo
GE reflux
Gastroparesis
Functional dyspepsia
Can domperidone cross the BBB
no
Can diphenhydramine cross the BBB
Yes
Why can domperidone not be used when cardiac function is impaired or pt has underlying cardiac disease
Can cause ventricular arrhythmia
What drug types reduce vestibular system signalling to the NTS to prevent nausea and vomiting
M3/5 receptor antagonists
H1 receptor antagonists
Are anti emetic drugs disease specific
No except for motion sickness
What are effects of the severe nausea and vomiting experienced by chemotherapy patients without anti emetic treatments
Treatment refusal
Tears in oesophag-gastric mucosa
Vertebral collapse
Metabolic alkalosis
Hypokalaemia
Hypocholoraemia
Extracellular fluid depletion
Dehydration - exacerbates nephrotoxicity
Malabsorption
Anorexia
Stress
Incapacitation
What are the 3 types of vomiting
Acute
Delayed
Anticipatory
Cannabinoid hyperemesis syndrome
Some chronic cannabis users develop severe cyclic vomiting and abdo pain starting in 3rd decade
Can THC be used to treat mild moderate or severe emesis
Mild or moderate
What are 5-HT3 receptor antagonists used to treat
Acute chemotherapy and radiation induced emesis
How does chemo cause vomiting
Chemo causes 5HT to be released from upper GI enterochromaffin cells which activates and sensitises the vagus nerve, cell breakdown releases inflammatory mediators
Are 5-HT3 receptor agonists effective against acute or delayed emesis
Acute
What causes acute emesis after chemo
5HT released from enterochromaffin cells activates 5HT3 receptors on vagus
What causes delayed emesis after chemo
Cell breakdown produces inflammatory mediators
What is given with 5HT receptor agonists for moderately severe emesis
Dexamethasone
What are NK1 receptor antagonists used for
Further control when given with other antiemetics
What part of the brain do dopamine receptor antagonists act on
Area postrema
Are NK1 receptor agonists better for acute or delayed emesis
Delayed
How do NK1 receptor antagonists work
Block actions of substance P - a NT used by vagus and some brainstem nerves
What combination of drugs is given for severe emesis
5HT3 receptor antagonist + NK1 receptor antagonist + Dexamethasone
What can cause vomiting in palliative patients
Opiate medications
Reflux
Gastric stasis
Intestinal obstruction
How is partial bowel obstruction treated
Stim GI propulsion - metoclopramide prucalopride
How is total bowel obstruction treated
Reduce inflammation - dexamethasone
Reduce fluid build up in bowel - octreatide, nasogastric tube, venting, gastronomy tube
Types of anti emetics
5HT3 antagonists
NK1 antagonists
D2 antagonists
H1 antagonists
Anticholinergic
Corticosteroid
Naturals
Adjuncts
What type of drug is olanzapine
Atypical antipsychotic
Antagonises loads of receptors
What can olazapine be used for
Nausea (given w 5HT3 NK1 and Dexamethasone)
Breakthrough vomiting
Interoception
Sensations of all tissues of the body, of physiological conditions or internal states, and of self awareness
Which brain areas have sustained activation during nausea
Interoceptive
Limbic
Somatosensory
Cognitive
What conditions cause gastric dysrhythmia
Gastroparesis
Functional dyspepsia
GERD
Motion sickness
Cycling vomiting syndrome
Nausea of pregnancy
Abdominal malignancy
Chronic renal failure
Anorexia
Chronic intestinal pseudo obstruction
Ischemic gastropathy
What is the only anti emetic used for gastroparesis
Metoclopramide
Tachygastria
Electrical activity in stomach in random uncontrolled pattern
