diarrhoea and vomitting Flashcards
(33 cards)
What are the major pathophysiological causes of diarrhoea?
- OSMOTIC - excessively eating things like lactose - so water just stays in the lumen
- MALDIGESTION - this is when you digest something that can’t be absorbed by the luminal lining
- SECRETORY- this is when there is abnormal ion channel function, this causes fluid which could contain bacteria toxins into the lumen and this causes the osmotic gap to be less than 50moM/Mg
- INFLAMMATION - the mucus is damaged so can cause problems and inflammation like IBS and ISCHEMIA
- DERRANGED MOTILITY - IBS, surgery , hyperthyroidism
- DIET, POISONING
- SIDE EFFECTS OF DRUGS - such as ethromyocin
What are the symptoms of diarrhoea?
Excessive volume and fluidity of stools (BS ≥ 5), increased frequency of defecation, urgency
- if a patient has bruises this could be a sign because they have hypokalaemia - lack of potassium
How is diarrhoea classified?
- Acute: lasts 3 days to 1-2 weeks, self-limiting
- Chronic: lasts more than 3-4 weeks, recurring diarrhoea, additional symptoms like fever and weight loss
What causes osmotic diarrhoea?
Excess of non-absorbable substances in the lumen, such as lactose, which holds water in the gut
What is maldigestion?
Inability to digest luminal contents due to maldigestion or malabsorption processes
What is secretory diarrhoea?
Abnormal ion transport in mucosal epithelium leading to fluid secretion into the gut lumen due to bacterial toxins, tumours, or genetics
What characterizes inflammatory diarrhoea?
Involves inflammation, often with fever, mucosal disruption, and abnormal absorption of nutrients and electrolytes
What is the osmotic gap for secretory diarrhoea?
< 50 mOsM/Kg
What is the osmotic gap for osmotic diarrhoea?
> 100 mOsM/Kg
What are common complications of diarrhoea?
- Dehydration
- Electrolyte loss
- Nutrient loss
- Failure to thrive in infants
- Micro-nutrient loss
What is the first choice drug for treating diarrhoea?
Loperamide (Imodium) - OPIOIDS
MOD - decrease intestinal motility, slows transits and increases time for absorption
SIDE EFFECTS- constipation, headache, nausea, fewer CNS side effects
codeine and morphine can also be used however has more side effects like drowsiness, dizziness, tachycardia, dry mouth
What is the mechanism of action of opioids in treating diarrhoea?
Decrease intestinal motility and slow intestinal transit to increase absorption of fluid and electrolytes
What is Racecadotril?
An antisecretory agent used as an adjunct to rehydration for symptomatic treatment of uncomplicated acute diarrhoea
What are common triggers for vomiting? V.O.M.I.T
- Vestibular disturbance
- Opioids Obstruction
- Mind
- Infection
- Toxins
What is the role of vomiting in the clinic?
It is a common and debilitating symptom, especially in cancer patients undergoing treatment
What are the consequences of severe vomiting?
- Dehydration
- Acid-base imbalance
- Hypokalaemia
- Mallory Weiss tear
What are the examples of 5-HT3 receptor antagonists?
- Granisetron
- Ondansetron
- Palonosetron
What is the therapeutic use of 5-HT3 receptor antagonists?
Treat acute phase of chemotherapy-induced vomiting and post-operative vomiting
What are the side effects of dopamine receptor antagonists?
- Sedation
- Tardive dyskinesia
- Galactorrhoea
- Impotence
- Postural hypotension
What is the use of Aprepitant?
Blocks NK1 receptors in CTZ, used for chemotherapy-induced emesis, especially delayed emesis
Fill in the blank: Diarrhoea is ________ in its genesis.
multifactorial
What is the role of dexamethasone in vomiting treatment?
Used in chemotherapy-induced vomiting, especially delayed vomiting
What is the main action of anticholinergics in treating vomiting?
Blocks muscarinic receptors in the vomiting pathway
What is the function of neurokinin receptor antagonists?
Block NK1 receptors activated by Substance P, which is emetogenic
