Introduction to Intravenous Access

Introduction & Overview of the Course

Introduction to Intravenous Access

Applications• Contrast injections

– CT– MRI– Intravenous urography– Venography

• Radiopharmaceuticals

• Drug administration – Buscopan, Glucagon– Frusemide

Venepuncture in Radiotherapy• Phlebotomy

– blood tests– White cell count

• pre chemotherapy• when large areas of bone marrow are treated

– Haemoglobin• tumour needs to be well oxygenated for maximal effect of

radiation

– Urea and Electrolytes– LFTs– Calcium concentration– PSA, Ca 125, aFP

Venepuncture in Radiotherapy

• Any types of scan CT, MRI, radionuclide

• Identification of kidney volume within treatment field– testicular seminoma- treatment to para-aortic

nodes. Should not be more than 1/3 kidney tissue in field

Venous anatomy• Superficial and deep

– arteries mainly deep

• Relatively thin walled

• Blood at low pressure

• Contain valves - can be problematic as cannula tip may be occluded by them

• Variable – some veins may be absent in certain individuals

• Bouncy - tendons hard• Can become very fragile in old age – liable to

“blow” leading to extravasation and haematoma. Use finest bore cannula possible

• Chemotherapy causes them to thin, sclerose and become hard to find

Venous anatomy

Venous anatomy of the hand

• 1. Digital Dorsal veins2. Dorsal Metacarpal veins3. Dorsal venous network

4. Cephalic vein5. Basilic vein

Posterior

Superficial venous anatomy of the arm

• 1. Cephalic vein2. Median Cubital vein

3. Accessory Cephalic vein4. Basilic vein

5. Cephalic vein6. Median antebrachial vein

Anterior

Venous anatomy of the arm

• Median cubital vein often prominent

• Also links to basilic vein which becomes axillary vein – most direct route to systemic venous circulation

• Preferable to cephalic vein which passes through clavipectoral fascia and may slow down passage of contrast for dynamic imaging

Superficial venous anatomy of the arm• Basilic vein

Ascends along the medial surface of the forearm; near the elbow, the vein changes to a position in front of the medial epicondyle where it is joined by the median cubital vein. It then runs along the medial margin of the biceps muscle to the middle of the upper arm, where it pierces the deep fascia to run alongside the brachial artery, becoming the axillary vein.

Cephalic vein

Ascends on the front of the lateral side of the forearm to the front of the elbow, where it communicates with the basilic vein through the median cubital vein. Then ascends along the lateral surface of the biceps muscle to the lower border of pectoralis major muscle, where it turns to pierce the clavipectoral fascia and pass beneath the clavicle. It then terminates in the axillary vein. There are valves at the termination of the cephalic vein. The sharp angles and valves may hinder the passage of a catheter along the cephalic system.

Median cubital vein

The median cubital vein arises from the cephalic vein just below the bend in the elbow and runs obliquely upwards to join the basilic vein just above the elbow. It is separated from the brachial

artery by the bicipital aponeurosis, which is a thickened portion of deep fascia.

Why veins are suitable for IV cannulation?

• Superficial• Palpable • Visible• Blood at low pressure• Relatively large internal diameter• Tough vascular wall – able to form seal around

cannula• Offer rapid route to systemic circulation• Many choices remote from sensitive structures

Vacutainer system• Used for phlebotomy

(blood samples)• Needle is screwed

onto barrel• Vacutainer tubes are

pushed inside barrel and suck out required volume of blood

• Allows for multiple blood samples to be safely taken

Vacutainer tube• Evacuated plastic tube containing different

chemicals depending on the type of blood test to be performed

Venflon cannula• Indwelling cannula

• Or when arm or hand likely to move possibly resulting in needle cutting out of vein

Indwelling portion

Stylet (removed)

Bung

Butterfly needle

• Useful for short-term use

• May have luer lock or diaphragm connector

Needle shape

Which way is correct?

Injection procedure• Identify correct patient• Explain procedure and obtain verbal consent• Obtain any relevant medical history

– History of reaction– Lymph node dissection

• Wash and glove hands• Tourniquet applied. Why?• Skin cleaned with alcohol

– allow to dry. Why?

Injection procedure

• Identify vein - should be straight proximal to the site of insertion

• Apply traction to skin distal to insertion point– helps to immobilise vein

• Introduce needle or cannula at an angle of about 15-30o

depending on depth of vein-too steep – likely to pass right through vein-too shallow – risk subcutaneous needle tip or vein dissection

• May feel slight pop as vessel wall penetrated• Should see blood flush back into end of cannula or tubing

of butterfly• Tape butterfly to arm/hand• Check with saline injection

Injection procedure for venflon• Advance plastic cannula off stylet

further into vein (hold stylet still) up to hub

• Press on arm proximal to insertion site to block vein and remove stylet (discard into sharps)

• Screw bung onto end

• Check correctly sited with saline– what is saline made of and what is

concentration?

• Apply dressing to venflon

Tips for finding veins• It is usually worth while asking the patient “Do you have a

good vein?”• Tight tourniquet

– but don’t give them ischaemia!• Make sure the patients arm is below the level of the heart• Clench and unclench fist• Usually visible as a blue line, but sometimes only palpable• Veins are bouncy, tendons are hard• Rub skin where you think vein is - why?• Bathing hands in warm water can help if all else fails• Applying the tourniquet for a minute and then letting it down,

waiting about 30 secs and then re-applying it also helps distend poor veins.

Which gauge?

• Depends on application

• Small injections (a few millilitres) or slow flow can use narrow gauge (23G, 25G)

• Rapid high volume injections e.g 100 mls IV bolus for CT requires larger gauge (20G)

Topical anaesthesia• EMLA

• Ametop

• Ethyl chloride

Removal

• Place sterile cotton swab over puncture site

• Withdraw needle smoothly

• Immediately press swab onto puncture site– hold for 2-3 minutes

• Check whether bleeding has stopped– who might bleed for longer?

• Apply dressing

Dangers• Haematoma• Extravasation

– compartment syndrome

• Sepsis• Vessel dissection• Arterial puncture!• Nerve damage• Air or other embolus• Maladministration

– wrong substance– wrong amount– out of date

Needle phobia• Use of anaesthetic creams

– particularly children

• Get them to look away

• Don’t lie but you can play down the pain– “like a sharp scratch”

• Get them to lie down

• If you don’t feel confident get someone else to do it.

• If likely to faint head between knees if sitting on chair

Administration Of IV Contrast Media

Radiographers performing IV administration

• Adequate training is paramount• Operate to agreed protocol and written scheme of

work• Employing authority should be informed &

assured of competency

Radiographers performing IV administration

• Need to be aware of:• Related anatomy, physiology and pathology• Correct choice and disposal of equipment

used• Criteria for choosing a vein• Indications/contraindications• Potential problems that can arise

Before the injection – the injector

• The person who administers the contrast medium should have a basic medical history of the patient, particularly relating to risk factors

• Be adequately trained in resuscitation procedures.

General Safety Issues

• Low osmolar CM agents are 5 to 10 times safer than the older high osmolar ones

• Major life-threatening contrast reaction is rare.– Incidence of severe reactions = 0.04%– Incidence of very severe reactions = 0.004%

• To minimise risk, it is important to identify individuals for whom there is an increased risk of an adverse event

• Appropriate steps to reduce the risk should always be taken.

Practical Safety Issues

• A Radiologist should be immediately available in the department to deal with an adverse reaction

• If risk factors present, decision to use CM must be made by supervising radiologist

• Avoid dehydrated patients due to increased risk of nephrotoxicity

• Facilities for treatment of adverse reaction should be readily available and regularly checked

Practical Safety Issues

• Do not leave patient alone in first 5 minutes post injection

• Advisable that patient remains on premises for at least 15 mins post injection. Most severe reactions occur within this time. – If patient = increased risk then this should be 30 mins.

• All CM reactions should be included in radiological report

Patient Information & Consent

• Patients should be fully informed about procedure and understand what it involves.

• Appropriate information leaflets should be available in dept.

• Person administering CM must ensure the patient understands that CM is to be given and agrees.

Identifying Patients at Risk

• Ultimate responsibility lies with prescriber• Essential information needed from patient:

– Previous contrast reaction– Asthma (increases risk by factor of 6 with LOCM)– Renal problems– Diabetes Mellitus– Metformin therapy

• This should always be checked before injection• Refer to Radiologist if any of the above present

Previous contrast reaction

• Determine– Exact nature of previous reaction– Agent used on that occasion

• Re-examine need for contrast agent, assessing risk-benefit ratio

• If deemed necessary– Use different, non-ionic or iso-osmolar agent to that previously

used– Close medical supervision– Leave cannula in place and observe pt for 30 mins– Treat any adverse reaction promptly. Have emergency drugs

available

Asthma

• Increased risk x6 with iso-osmolar non-ionic contrast

• Is the asthma currently well controlled?

• Defer if not or patient wheezy

• If well controlled re-assess need and take same action as for previous contrast reaction

Other Special Cases

• Pregnancy– In exceptional circumstances OK to administer CM –

risk of thyroid suppression in Foetus

• Lactation– Small % injected dose enters breast milk. No special

precautions required

• Thyroid– IV CM should not be administered if patient is

hyperthyroid. Affects treatment for Thyroid cancer.

Before the injection

• Check the date & type of contrast agent• Check the quantity & concentration of

contrast agent• Route of administrations• Check the temperature (affects viscosity)

& condition of glass container (ie not broken)

• Check the patients details (correct?), h/o reactions / allergies (review patients notes if possible / look up patient history on RIS)

Before the injection

• Check to ensure clarity of contrast agent (ie no foreign particles in solution)

• Check the above details with the radiologist or injecting radiographer.

• Ensure request form has been signed!• Check emergency equipment available

During the Injection

• To avoid potential complications, the patient’s full cooperation must be obtained.

• Communicating with the patient before, during and after the contrast medium injection is essential.

• If the patient reports pain or the sensation of swelling at the injection site, injection should be discontinued.

• Intravenous injections may cause heat and discomfort but rarely cause pain unless there is extravasation

Injections methods vary depending on vascular access, clinical problems, and type of examination. The method of delivery, either by hand or power injector, also vary per procedure.

Preventing Extravasation

• Check IV for free return of blood.

• Inspect and palpate the site early in the injection.

• If extravasation – STOP the injection immediately.

Extravasation. Therapy

Can be very painful

Depends on local protocol: • <20ml

• elevation recommended, • Observe

• >20ml• Call Radiologist• Cold compress: decreases

inflammatory response, blistering

After the injection

• The patient should not be left alone following injection, particularly during the first 5 mins

• Before patient leaves your care– Ask if feeling OK. If not monitor; get medical assistance if do not

recover – Check puncture site for bleeding or haematoma – If bleeding or haematoma developing achieve haemostasis by

further pressing with cottonwool

• Dispose of sharps safely• After examination, check pt is fit to travel• Do not let them leave if there is any doubt

Record keeping

• Name of injector (usually initialled)• Date & type of contrast medium • Quantity & concentration of contrast medium• Record any adverse reaction to the administrated

contrast medium (even though the reaction could very mild).

• Any adverse reactions should be reported to manufacturer