Dosing and calculations Flashcards
what are 6 medications that can cause serious harm in calculation error?
APINCH
Antimicrobials
Potassium and electrolytes
Insulin
Narcotics
Chemotherapy
Heparin and anticoagulants
what are 3 cautions needed when administering insulin?
only use insulin syringe - scale in units rather than ml
do not withdraw insulin from insulin pen or refill cartilage
Write units in full for insulin
why are children vulnerable to dosing and calculation errors?
small dose errors have more of an effect on a child
doses need to be calculated on weight - individualised dosing
liquids vary in strengths
confusion between ml and mg dosing
non-licensed preparations
what is the ideal body weight?
used to calculate dose of water soluble medications (e.g. gentamicin) to avoid obese people being overdosed
what is the general formula for lean body weight?
LBW = actual body weight - body fat weight
what are 4 ways to estimate paediatric weight in an emergency?
body length - broselow emergency paediatrics tape
Age - paediatric emergency drug chart
Weight = (age + 4) x2 - up to 10 years
concentration =
mass/volume
what is a weight/weight percentage?
weight of active ingredient in 100g of medication
e.g. 0.5% cream = 0.5g in 100g of cream
what is weight/volume percentage?
weight of medication in 100ml of solution
0.9% saline = 0.9g of NaCl in 100ml of solution
what is volume/volume percentage?
ml of liquid medicine in 100ml of final product
How many lb in a stone?
14 pounds
how many grams in 1lb?
450g in 1lb
how many kg in one stone?
6.35kg in one stone
how many inches in a foot?
12 inches
how many mm in 1 inch?
25.4mm in 1 inch
what is 1 foot in mm?
1 foot = 304.8mm
what is the usual conversion between oral codeine and oral morphine?
codeine is 10x weaker than morphine orally
what is the usual conversion from oral to SC/IV morphine?
Oral morphine is half as potent as SC/IV
what is the conversion from SC/IV diamorphine to oral morphine?
SC/IV diamorphine 3x stronger than oral morphine
what is the opioid dosing for breakthrough pain?
1/10th to 1/6th the daily dose
what is the equivalent dose of chlordiazepoxide to 5mg diazepam?
12.5mg chlordiazepoxide
where can benzodiazepine dose equivalents to diazepam be found in the BNF?
hypnotics and anxiolytics treatment summary
where can you find dose conversions for steroids compared to 5mg of prednisolone in the BNF?
glucocorticoid therapy treatment summary
what is the conversion for 5mg of pred to dexamethasone based on glucocorticoid activity?
750micrograms dex for 5mg pred
how to calculate volume of parenteral medicine?
volume required = (dose X volume of solution)/amount of medicine in solution
