Misc. Flashcards
What is suxamethonium apnoea?
A small subset of the population has an autosomal dominant mutation, leading to a lack of the specific acetylcholinesterase in the plasma which acts to break down suxamethonium, terminating its muscle relaxant effect. Therefore, the effects of suxamethonium are prolonged and the patient needs to be mechanically ventilated and observed in ITU until the effects of it wear off.
What is the normal range of sodium (ECF)?
135-145mmol/l
What is the normal range of potassium (ECF)?
3.4-4.9mmol/l
What is the normal range of chloride (ECF)?
95-105mmol/l
What is the normal range of bicarbonate HCO-3?
21-28mmol/l
What is the normal range of urea?
2.5-7.1mmol/l
What is the normal range of creatinine?
40-130mmol/l
What is the normal range of calcium?
2.5mmol/l
What is the normal range of albumin?
40-52g/l
In terms of fluid loss, what constitutes ‘insensible losses’ and how much do these account for on average each day?
This is fluid lost through the skin, respiration and normal faeces. It accounts for around 800ml/day
Where will dextrose 5% water be distributed in the body?
As it can cross the lipid bilayer, it will be distributed in the ICF compartment and the ECF compartment.
Where does saline 0.9% NaCl get distributed?
Just in the ECF
What do measured losses account for?
Urine, surgical drains, fistulae, vomit and diarrhoea
How many litres of fluid is the body composed of?
40 litres approximately
Of the 40 litres of fluid, what percentage is extracellular fluid and what percent is intercellular?
1/3 = ECF (15L) 2/3 = ICF (25L)
Of the extracellular fluid, what is this divided into?
Intravascular and interstitial fluid
How much of the ECF is intravascular and how much is interstitial?
20% intravascular and 80% interstitial
What is the action of albumin?
It is the protein that travels in the blood vessels, keeping water within the vessels. Hence why when albumin levels drop, there is an increase in interstitial fluid and people become oedematous
Why is Hartmann’s liked by surgeons?
It is the fluid replacement that is most comparable to normal physiological distribution e.g. Na 131, K 5, and Cl 111.
What are the CYP450 inducers?
PC BRAS Phenytoin Carbamazepine Barbiturates Rifampicin Alcohol Sulphonylureas St John's wort
What are the CYP450 inhibitors?
GOA DEVI2CES Grapefruit juice Omeprazole Allopurinol Amiodarone Disulfiram Ethanol (acute) Vancomycin Isoniazid Ciprofloxacin Erythromycin Sulphonamides Sodium valproate
Which drugs are inhibited/induced by the inhibitors and induces?
- Warfarin
- Statins
- Lithium
- Corticosteroids
- COCP
- Desogestrel
Which drugs should be stopped before surgery?
- Anti-platelets - 7 days prior (aspirin, clopiodgrel)
- Anticoagulants - warfarin - 5 days prior (INR must be 1.5 at surgery)
- Hypoglycaemics day of - gliclazide, piogiltazo, metformin
- COCP/HRT 4 weeks prior
What are the hepatotoxic drugs? (5)
- Amiodarone
- Statins
- A/Ps
- Azathioprine
- Sodium valproate
What are the nephrotoxic drugs? (8)
- ACEi / ARBs
- NSAIDs
- Diuretics
- Tetracyclines
- Gentamicin
- Vancomycin
- Nitrofurantoin
- Metformin
Which drugs will accumulate in renal failure? (5)
- Opioids
- Digoxin
- Atenolol
- Allopurinol
- Sulphonylureas
What are the side effects of steroids? mnemonic NSTEROIDS
NSTEROIDS
- Neutrophilia
- Stomach ulcers
- Thin skin
- oEdema
- R+L heart failure
- Osteoporosis
- Infection
- Diabetes
- Cushing’s syndrome + Confusion (elderly)
Why should steroids never be stopped suddenly?
There is a risk of Addison’s crisis
What are the contraindications for NSAIDs?
NSAID N - nephrotoxic - AKI S - systolic dysfunction - heart failure A - asthma I - indigestion - ulcers (PPI) D - dyscrasia - clot
Which folate antagonists should not be given simultaneously and why?
Trimethoprim and methotrexate - leads to bone marrow suppression, pancytopenia and neutropenic sepsis
What are the side effects of diuretics? (3)
- Hypokalaemia
- Hyponatraemia
- Renal failure
What happens in the renin-angiotensin-aldosterone system?
Renin is produced by the kidneys. Renin is an enzyme that splits the protein angiotensinogen into angiotensin I. ACE converts angiotensin I into angiotensin II.
Where in the kidneys is renin produced?
Produced by the juxtaglomerular cells in the afferent arterioles in the kidneys
Where is angiotensin-converting enzyme found?
In the lungs primarily but also in the kidneys