PPT - PAIN, NAUSEA, VOMITING, IV FLUIDS Flashcards
What are examples of strong opioids?
Morphine
Diamorphine
Buprenorphine
Dipipanone hydrochloride
Afentanil
Fentanyl
Remifentanil
Methadone
Oxycodone
Pentazocine
Pethidine
Tapentadol
Tramadol
What are examples of weak opioids?
Codeine phosphate
Dihydrocodeine tartrate
Meptazinol
What are the acute side effects of opioids?
Nausea
Sedation
Confusion
Hallucinations
Flushing and sweating
Dry mouth
Hypotension
Pruritis and urticaria (‘morphine itch’ caused by mast cell degranulation)
Delirium
Myoclonus
Hyperalgesia
Visual disturbance
Respiratory depression
What are the chronic side effects of opioids?
Constipation
Difficulty with micturition and urinary retention
Delirium
Sexual dysfunction
Biliary/ureteric spasm
How do you manage respiratory depression from opioid use?
Naloxone
What are the key things to remember about naloxone?
Half life is much shorter than other opioids
Rapid onset - it can restore normal breathing in 2-3 minutes
What ate the features of opioid misuse?
rhinorrhoea
needle track marks
pinpoint pupils
drowsiness
watering eyes
yawning
What is pethidine?
A synthetic opioid which is structurally different from morphine but which has similar actions. Has 10% potency of morphine.
Short half life and similar bioavailability and clearance to morphine.
Short duration of action and may need to be given hourly.
Why do anaesthetists use multi-modal analgesia? (I.e. using more than 1 drug)
To target different parts of the pain pathway
Allows you to use a lower dose if any - particularly important in opioids
What are the main effcts of morphine?
Pain relief
A state of euphoria and mental detachment
Commonly causes nause and vomiting
What is Buprenorphine?
Has both opioid agonist and antagonist proerpties and may precipitate withdrawal symptoms in pt dependant on other opioids
What receptors do we want to target our drugs at for travel sickness?
H1 and M1 in vestibular system
What receptors do we want to target our drugs at for nausea caused by drugs such as opioids?
Target CTZ or vomiitng centre - D2, neurokinine and 5-HT3 receptor
What receptors do we want to target our drugs at for nausea caused by something in the GIT?
Mechanoreceptors
Chemoreceptors
5HT3 receptors
What drugs do we give for post-operative nausea?
Serotonin receptor antagonists e.g. ondansetron
Others:
Glucocorticoids - dexamethasone
Anticholinergic e.g. promethazine
Neurokinin receptor antagonist e.g. aprepitant
Whats the current issue with using cylizine for nausea?
IV cyclizine has actually been shown to give a ‘rush’ so there is abuse potential - recently people have been faking nausea and vomiting in ED in order to receive IV cyclizine
Why did we move away from using IV pethidine for renal colic?
The abuse potential - pt would come in to ED Pethidine seeking
We now use IM diclofenac
Whats the moa of Ondansetron?
5HT3 antagonism both peripherally and in CTZ
Whats the issue with Ondansetron at a high dose?
Can prolong the QT interval
Whats the moa of glucocorticoids for post operative nausea and vomiting?
Not known
Whats the moa of anticholinergic drugs for post operative nausea and vomiting?
Unknown - possibly by blocking communication to vomitin centre
Whats the moa of neurokinin-receptor antagonists for post operative nausea and vomiting?
Blocks neurokinin effect at receptor site (this is a proemetic agent)
Whats the issue with neurokinin receptor antagonists?
Expensive!!
Whats the problem with metoclopramide use for emesis?
It causes acute dystonia - particularly in young females
What can you give to treat drug-induced dystonia reactions?
Procyclidine
Who should not receive metoclopramide?
Anyone under 20 particularly females
What are examples of sodium containing fluids?
0.9% sodium chloride (isotonic)
Hartmanns solution - compound sodium lactate (isotonic)
What are examples of glucose containing fluids?
5% glucose (isotonic)
10% glucose, 20% glucose or 50% glucose (hypertonic examples)
Outline the NICE guidelines for fluid resuscitation?
Give a fluid bolus of 500m crystalloid fluids over <15 minutes (e.g. 0.9% sodium chloride or Hartmanns)
Reassess using ABCDE
If they still need fluid then give further fluid bolus of 250-500ml of crystalloid
Up until the point you reach 2L of fluid - after this point you need to seek expert help
Outline NICE guidance for routine fluid maintenance?
Maintenance IV fluids:
25-30ml/kg/d of water
1mmol/kg/day sodium, potassium + chloride
50-100g/day glucose
Reassess and monitor the pt
How logbook does oramorph last?
4 hours
give 6 times a day or every 4 hours
Whats the risk of using large volumes of 0.9% saline?
Increased risk of hyperchloraemic metabolic acidosis
When is hartmanns contraindicated?
In hyperkalaemia as it contains K+
