pencils DDS parenteral drug delivery

IV winged steel needle “butterfly needle”

wings facilitate insertion & may be taped for stability

catheters

made of flexible plastic or silicone

“over the needle” catheter- needle inside is flexible catheter, it is removed after insertion

catheters cont

bc of their flexibility they can be used for longer term IV administration than needles… they are less likely to damage the vein

gauges 

increase in gauge # the smaller the diameter 

ex: 28-31 G insulin needles very thin to minimize pain 

central IV

superior vena cava or right atrium

rapid dilution, less risk of irritation

catheter insertion sites: subclavian & jugular vein

central catheters and lumen

central catheters can have more than one lumen

each lumen could be for a diff purpose (diff infusion fluids)

each lumen could have a diff gauge (large gauge for high volume or viscous fluids)

scalp (peripheral) 

common for infants under 6 months 

scalp has many superficial veins 

midline

areas are basilic, cephalic, or brachial veins

midline advantages

good for pts w poor peripheral vein access

x-ray not needed to confirm placement

hemodilution

allows for longer therapy than peripheral sites (up to 4 weeks)

bolus (push) 

injection given over a very short time usually several minutes up to 30 min 

potentially dangerous method of drug administration if injected too quickly (may lead to dangerously high drug lvls, local & systemic)

notable features about IV administration

it provides rapid action (IV injected drug reach heart & brain in 10-20 sec & circulation in 1 min

a wide volume range may be injected/infused (1ml-3L can be injected/infused)

IM diverse possibilities

potentially 2nd to IV in onset (IM onset about 3-5 min bc muscles are well perfused)

IM sites can act as depot injection sites- act as a storage reservoir where medication is slowly absorbed and prolonged effect

IM injection volumes 

gluteal buttock- 5ml in each cheek total of 10ml altogether 

deltoid- 2ml 

no more than 1ml if it is a child less than 3 

IM compared to IV

easier administration site, IM sites accept more diverse formulations

IM accepts oil & suspension formulations

notable features of SC administration

SC injected drug can be absorbed directly into blood vessels and into the lymphatic capillaries

lymphatic capillaries slowly drain interstitial fluid to the lymph nodes then the bloodstream

SC onset slower than IV & IM due to the poorer blood supply & slow lymphatic transport

SC injection volume= 2ml

provides relatively safe administration route (lower risk of hitting vein or nerve) (SC most common for self injecting)

intradermal injection volume 

0.1ml