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BÀI GIẢNG DÀNH CHO SINH VIÊN Y KHOA, BÁC SĨ, SAU ĐẠI HỌC Introduction to invasive BP monitoring „ Understanding of what is required „ Introduction to waveform analysis „ Understanding of potential complications „ Understanding of the care & safety issues of Arterial lines

Arterial Lines

Peter Branfield

Aims & Objectives

„ Introduction to invasive BP monitoring

„ Understanding of what is required

„ Introduction to waveform analysis

„ Understanding of potential

complications

„ Understanding of the care & safety

issues of Arterial lines

Arterial Blood Pressure (BP)

„ Pressure exerted on arterial wall

„ Determined by flow & resistance

„ BP=SV X HR X SVR

„ MAP more accurately indicates

perfusion

„ MAP = (SBP – DBP)/3 + DBP

Automated Non-invasive BP

– Oscillometry

– Measures blood flow induced oscillation

– Sensed as pressure changes & analysed

Automated Non-invasive BP

„ Can be uncomfortable

„ Pressure risk

„ Occlusion of infusions

„ Important to get the size right

„ Least useful when most needed

„ Greater frequency & accuracy needed

in ICU

Invasive Blood Pressure -Why?

– Cardiovascular instability

– Inotropes or vasodilators

– NIBP difficult or inaccurate

Pressure Transducers

„ Requires correct setting up

– Continuous fluid pathway

– No air bubbles

– Non-compliant manometer tubing– Zeroed to atmospheric pressure– Level with the phlebostatic axis– No additional tubing

flush device

questionable

Sites for Arterial Lines

„ Large limb artery

– Anacrotic notch

• Severe aortic stenosis

Waveforms at Different Sites

steepness & height of

upstroke

location of the dicrotic notch

„ Cannulation can be difficult

„ Potential complications include

– Distal ischaemia – Infection

„ Contributing factors

– Lack of knowledge – Rule –based errors – Busy

– Lack of support /supervision

Durie, Beckmann Gillies 2002

Death by Arterial Line

– ? Stroke

comatose

solution-contaminated samples

Nursing Care

What do you think are the Key issues for

the nursing care of a patient with an

arterial catheter?

5 minutes to discuss

Nursing Care (2)

locks

– To prevent accidental disconnection

an appropriate dressing

– To maintain asepsis

sampling three-way tap

– To ensure correct identification of the arterial line

Nursing Care (3)

„ Never inject anything

into an arterial cannula

or arterial line

– Concentration of a drug into the tissues served by the cannulated artery can result in cell death

– skin necrosis, severe

gangrene, limb ischemia, amputation & permanent disabilities

Accidental Arterial Injection

– Local irritation to intense pain

– Flushing, mottling

– Tinkling, burning

– Muscle contractures, weakness

Accidental Arterial Injection

Nursing Care (4)

„ Ensure that the flush bag has adequate fluid

„ Use only 0.9% sodium chloride

„ Ensure that the pressure in the pressure bag is maintained at 300mmHg

„ Do not allow the flush bag to empty

– To maintain patency of arterial cannula.

– To prevent air embolism

– To maintain accuracy of blood pressure reading

– To maintain accuracy of fluid balance chart

– To prevent backflow of blood

Nursing Care (5)

the transducer set

– Tubing is rigid and non compliant & correct length

– To ensure accuracy in measuring blood pressure Air unlike fluid is compressible as a result the

pressure waveform will be dampened

syringe driver instead of the flush bag

– To prevent fluid overload

Nursing Care (6)

„ Monitor colour & temperature of limb

distal to arterial line & compare to other limb

– To confirm that circulation to the limb is

adequate

– To ensure the early detection of impaired circulation

Nursing Care (7)

„ Monitor and display the arterial

waveform at all times

– To detect cannula disconnection

„ Rezero transducer once per shift

– To ensure accuracy in measuring blood pressure

„ Explanation to patient and relatives

Nursing Care (8)

patient’s phlebostatic axis (fourth intercostal space midaxillary line)

– To ensure accuracy in measuring blood pressure.

appropriate to level the transducer to the

tagus of the ear

– In order to correctly calculate cerebral perfusion pressure (CPP).

Nursing Care (9)

pressure over puncture site for at least 5 minutes until bleeding has stopped

– To prevent bleeding and haematoma formation

– Only if suspected infection

– To detect infection

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Anderson, L.E (Ed.) (1998) Mosby’s medical, nursing, and allied health dictionary (5 th Ed.) St Louis: Mosby Campbell, B (1997) Arterial waveforms: Monitoring changes in configuration Heart and Lung , 26 (3), 205-215 Chulay, M (1995) Ask the experts Critical Care Nurse , 15 (2), 108.

Chulay, M., & Holland, S (1996) Ask the experts Critical Care Nurse , 16 (6), 103-107.

Chulay, M., & Holland, S (1997) Ask the experts Critical Care Nurse, 17 (3), 14-16.

Gamby, A., & Bennett, J (1995) A feasibility study of the use of non-heparinised 0.9% sodium chloride for

transduced arterial and venous lines Intensive and Critical Care Nursing , 11 (3), 148 – 150.

Daily, E., & Schroeder, J (1995) Techniques in bedside hemodynamic monitoring (5 th ed) St Louis: Mosby Darovic, G., Vanriper, J., & Vanriper, S (1995) Arterial pressure monitoring In Darovic, G (Ed.), Hemodynamic Monitoring: Invasive and noninvasive clinical application (pp.177-210) Philadelphia: W.B Saunders

Company.

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monitoring: Invasice and noninvasive clinical application (pp.149-175) Philadelphia: J.B.Lippincott