CANNULATION &
VENESECTION
AMANDA HARPER
CLINICAL SKILLS
COORDINATOR
LEARNING OUTCOMES OF
THE WORKSHOP
• Assessment of patient
• Demonstrate the correct technique for performing
cannulation & venesection as per SUHT policy &
procedure
• Selection of the appropriate device
• Identify and recognise the complications that are
associated with cannulation & venesection
• Correct documentation as per SUHT policy
Patient Assessment
&
Vein Selection
THE ASSESSMENT
CONSIDER THE FOLLOWING POINTS:
• Age / size / history / condition / dependency of
the patient
• History of previous cannulation / venesection
• Type / length of treatment required
• Number of tests ordered
• What medication is the patient on?
• Fluid status
• History of blood disorders
Conditions that affect the
position of the device: • Amputation
• Stroke
• Mastectomy or other Breast / Lymph Surgery
• Renal Fistula
• Lymphoedema or Cellulitsis
• Diabetes / Vascular Disease / Arthritis
• Trauma / Fractures / Burns
• Social History
Questions to ask the patient
• OBTAIN CONSENT
• Have you had a cannula / blood test before?
• Were there any complications / adverse
reactions?
• Do you have any allergies?
• Consider needle phobia
• Would you like a local topical anaesthetic
before I insert the cannula or take blood?
• Which is your dominant arm?
Attributes of an ideal vein
are: • Be engorged, bouncy & soft
• Refill after it has been depressed
• Be visible
• Feel round
• Be well supported by surrounding
structures
• Be straight & ‘free of valves’
Veins to be avoided: • Thrombosed, fibrosed or sclerosed
• Inflamed or bruised or painful
• Thin or fragile
• Mobile
• Near bony prominences and joints
• Near sites of infection or oedema
• AVOID THE VALVES
• For venesection avoid the arm with an
IV line running
Methods for improving
venous access:
• Apply a disposable tourniquet
• Lower the level of the arm below the heart
• Ask the patient to open and close their fist
• Light tapping / rubbing of the veins
• Warm compresses over the selected vein
• Warm water
• Relax the patient / consider the environment
WHICH
VEIN?
Antecubital Fossa
Cephalic
1st Intercostal
Brachial Artery
Basillic
Radial
Median Cubital
Vein
Radial
Artery
Median
Veins
Ulnar Artery
Ulnar
Arteries
Nerves
DIGITAL
DORSAL
VEIN
DORSAL
METACARPAL
VEINS
DORSAL
VENOUS
NETWORK
CEPHALIC
VEIN
BASILLIC
VEIN
VEINS TO BE USED ARE:
• METACARPAL VEINS
• CEPHALIC VEIN
• BASILIC VEIN
• MEDIAN CUBITAL VEIN
GROUP EXERCISE
In pairs, use a tourniquet to identify each
others:
• Veins
• Arteries
• Valves
• Ligaments
CANNULA
SELECTION
Selecting the right cannula
Two key points to consider:
• What is the cannula going to used for?
• The condition, location and size of the
vein selected?
You should try to select the smallest
gauge possible that will accommodate the
intravenous therapy that is prescribed.
Colour
Size
Flow
Ml/min
Uses
Brown
14
275
Rapid transfusions of whole blood.
Emergency situations.
Grey
16
173
Rapid transfusions of whole blood.
Emergency situations
Green
18
100
Blood transfusions
Pink
20
60
IV infusions. Bolus’
Blue
22
25
Bolus’. Maintenance infusions
Yellow 24
13
Bolus medications. Short term
infusions. Neonates
Purple
26
Neonates
SGH, exceptions to this rule: Patients Condition
Cannula Size
All obstetric patients
Grey
Active gastrointestinal
(GI bleed)
At risk of GI bleed
Brown or Grey
At risk of epileptic fit
Green
At risk of cardiac event
Green
At risk of neurological event
Green
Grey
VENESECTION
DEVICE SELECTION
VACUTAINER
• Quicker collection than other methods
• Closed system
• Exact amount of blood obtained
• Reduces the risk of haemolysis of the sample
• Reduces the risk of needlestick injury
BOTTLES & BLOOD FORMS
• E-QUEST SYSTEM for blood requests &
results within SUHT
• ALWAYS ensure that the GROUP &
SAVE or CROSSMATCH request has
been correctly completed & signed for by
the requesting MEDICAL PRACTIONER
Serum
E.D.T.A.
AB Levels
FBC & ESR
Coagulation
INR / APTR
Cross Match
Group &
Save
Glucose
Lithium
Heparin, PST,
U&E’s, Bone &
Liver
Trace
Elements
ORDER OF DRAW
• NO ADDITIVES (Green, Red, Dark Blue)
• COAGULATION (Light Blue)
• OTHER ADDITIVES (Gold, Lilac, Pink & Grey)
EXCEPTION to this is when Blood Cultures have
been requested, these MUST BE filled first –
aerobic (Blue) followed by anaerobic (Pink)
Risks and
Complications of
Cannulation &
Venesection
Risks - During Insertion
• Infection
• Transfixation
• Haemorrhage
• Pain
• Haematoma
• Nerve damage
• Vaso-vagal episode
• Arterial puncture
• Needle phobias
• Allergies
• Catheter embolism
• Needlestick injury
(cannulation)
Transfixation
Skin
Vein wall
Vein wall
Haematoma/Bruising
• Transfixation
• Tourniquet too tight / left on too long
/ use of RUBBER GLOVE!
• Arterial puncture
• Repeated insertion sites
Future Complications of
Cannulation
• Phlebitis — septic / mechanical / chemical
• Infection
• Drug reaction / Allergy
• Infiltration
• Extravasation
• Thrombosis / Embolism
• Speed shock
• Fluid overload
Phlebitis
• TYPES OF:
Infiltration
• “The inadvertent administration of non-
vesicant (non-toxic) solution/medication into
surrounding tissues."
(Royal Marsden Manual, 2004)
• The cannula may still appear to be patent, so
early recognition is vital to avoid tissue damage.
• Examples of fluid include: Normal Saline &
5% Dextrose
Extravasation
• “the inadvertent administration of a vesicant
substance (toxic) into the tissues
surrounding a vein.”
(Royal Marsden Manual, 2004)
• Examples of fluid include: 10% Dextrose,
Chemotherapy & Potassium
Thrombus Formation
• Correct flushing technique - pulsated pushpause & positive pressure, prevents blood
being left in the cannula & removes debris
from the internal catheter wall (use 5mls
of Normal Saline).
• Flushing blocked cannula can lead to
pulmonary embolus (30% PMs show
undiagnosed PE).
Signs of Cannula
Related Infection
• Phlebitis
• Pyrexia
• Feeling unwell
• Raised white blood cell count
Site preparation
• As cannulation / venesection is performed using an
aseptic non-touch technique it is imperative
that the vein is cleaned PRIOR TO THE
PROCEDURE, wearing clean non-latex gloves
• Clean the vein for 30 seconds with 2%
chlorhexidine in 70% alcohol solution, cleaning the
vein in a criss-cross motion
• Allow vein to air dry
• DO NOT re-touch or palpate the vein once
cleaned
• Consider hair clipping if appropriate
DOCUMENTATION
• SEE CANNULA CARE PLAN includes:
• Time & date of blood sample / cannula
insertion
• Site of insertion
• Gauge and batch number of the cannula
• What blood samples have been taken
• Number of attempts (MAX 2 per person)
• Any complications noted (e.g. haematoma)
• Print & sign your name
• Evidence verbal consent has been obtained