CPS Revision 20/03

You have an 87 year old lady who requires gentamicin as part of treatment for sepsis. In order to calculate the correct dose you must calculate her creatinine clearance.

Her adjusted body weight (ABW) is 55.6kg. Creatinine is 80.

What is her creatinine clearance?

CrCl (ml/min) in females = ((140 – age in years) x 1.04 x ABW in kg ÷ Serum creatinine (micromoles/l).

You are asked to prescribe a unit of blood (350ml) over 3 hours by your consultant. The student nurse asks for your help in checking she has got the drip rate right. What rate is required for the unit to be given over 3 hours at 15 drops/ml?

You have a patient with a low magnesium and need to prescribe a transfusion of magnesium sulphate in 250ml 5% glucose. How many g of glucose will they receive?

The plasma concentration of a drug (P, mg/L) given to a patient can be expressed as P = 0.1d + 32. d is dose given in mg.

The plasma concentration of a drug was found to be 130mg/L.

What dose of drug was given to the patient? (with units)

0.1ml of an enzyme produces 3.7 x10-7 moles of a product per minute.

What is the activity of the enzyme in units per litre of serum?

(1 unit is the amount of enzyme that produces 1 µmol of product per minute)