Preparing & administering Infusions

Mark Tomlin

Consultant Pharmacist: Critical Care

Southampton University Hospitals NHS Trust

Why Parenteral?

• Rapid onset of action

• Achieving high blood/tissue concentrations

• Reliability

• Initial loading

Whether an alternative route should be considered?

• Injections are expensive and hazardous• IM, SC may be painful or have erratic absorption• Oral route may be unavailable, but consider

NG, NJ, PEG/J• Nausea, vomiting, diarrhoea, ileostomy, gut

surgery• Rectal inappropriate clinically/pharmaceutical• Transdermal

What route ?

• Central • Or peripheral

What route ?

• Central• Measuring CVP, PAWP• Concentrates in fluid

restricted patients• Too irritant peripherally• Slow and risky to gain

access – needs experience & practice

• Or peripheral• Easy and safer

access• Large volumes• Familiar route

Where to prepare?

Treatment Room

Aseptic Suite in Pharmacy (CIVAS)Toilet

Theatres

When to prepare ?

Immediately before Use

Before the weekend A week before you need it

Before they go to theatre

24 hours before you need it

How to prepare & administer

• Reconstituting Cefuroxime 750mg vial• Administering Metronidazole 500mg IV• Preparing Rifampicin IV• Diluting Propofol• Piggy – backing• Y –site into a running infusion• How to find the correct diluent• Lignocaine, Saline, Water, Potassium• Potassium

What IV fluid - 1 ?

• Crystalloid • or colloid?

What IV fluid - 1 ?

• Crystalloid• Most familiar• Cheap• May need large

volumes• Relatively slow

increase in CVP• Will move out of

vascular space

• or colloid?• HDU/ITU and critically

ill only• Expensive• Rapid increase in CVP• Small volumes• Water redistribution

out of tissues

What IV fluid - 2 ?

• Saline, Glucose or Dextrose/saline

• What strength ?

• The list of choices

• Serum sodium

• Diabetes

• Acid-base

Fluid balance

• A simple question of input equal to output• A straight question of 3L in, and 3L out• A question of giving sufficient fluid to achieve 1mg/kg/hr

urine output• A complex balance of forces to achieve a urine output of

about 1mg/kg/hr (assuming normal renal function) without causing heart failure, pulmonary or peripheral oedema

• Achieving an adequate urine output (accounting for other losses) with a maintenance dose, and giving treatment doses to sustain BP&CO

• Giving a fluid challenge to ask the question about whether the patient is adequately filled (BP, CRT)

Problems with infusions and fluids

• Forget it is still running !• Incorrect calculation

Wrong doseWrong rate Wrong concentration (Flolan) Wrong infusion device or Wrong set-up

• Changes - equipment, rates & concentrations• The F word and when to use it?