DOSING AND CALCULATIONS Flashcards
what are the high risk medications for making calculation errors?
A-PINCH
A - antimicrobials
P - potassium and electrolytes
I - insulin
N - narcotics
C - chemotherapy
H - heparin and anticoagulants
how can you avoid calculation errors with insulin?
Only use insulin syringes to withdraw insulin from vial
Always write units in full (do not abbreviate)
what standard of practice is in place to check drug calculations?
independent second checks
what are the conversion factors between different weight measurements?
what does %weight/weight (%w/w) mean?
In 1% w/w preparation there is 1g of medicine in 100g of final product
Example hydrocortisone 0.5% w/w
0.5g of hydrocortisone in 100g of cream
what does %weight/volume (%w/v) mean?
In 1% preparation there is 1g of medicine in 100ml of final product
Example sodium chloride 0.9% w/v
0.9g sodium chloride in 100ml of infusion
what does %volume/volume (%v/v) mean?
In a 1% v/v solution there is 1ml of liquid medicine in 100ml of final product
how do you interpret ratios of medications?
1:1000 means 1g in 1000ml
1:100000 means 1g in 100000ml
what are some basic weight conversions?
1 stone = 14lbs
1lb = 450g
1 stone = 6.35kg
what are some height conversions?
1 foot = 12 inches
1 inch = 25.4mm
1 foot = 304.8mm
where would you find the BNF conversion chart for opioids?
prescribing in palliative care
what dose of opioid would you provide for breakthrough pain?
1/10-1/6 of the total daily dose
where would you find the BNF conversion chart for benzodiazepines?
hypnotics and anxiolytics
where would you find the BNF conversion table for corticosteroids?
glucocorticoid therapy
how do you calculate the infusion rate?
rate = volume / time
