presentation of the topic describing the importance of use of invasive monitoring for patient under anesthesia undergoing surgery

1. ARTERIAL AND CVP MONITORING
IN PERIOPERATIVE PERIOD
Mohamed Khelifa
Anesthesia Technologist
Certified Patient Safety Officer
Alwakra Hospital

2. HYMODYNAMIC MONITORING
 For patient undergoing surgery associated with rapid hemodynamic
changes, adequate hemodynamic monitoring should be available at all
times With the Ability to measure and record almost all vital physiologic
parameters.
 The development of acute hemodynamic changes may be observed and
Corrective actions may be taken in an attempt to correct adverse
hemodynamics And improve outcome.
 This is based on the presumption that the data obtained from these
monitors are interpreted correctly and that therapeutic decisions are
Implemented in a timely fashion.

3. INVASIVE ARTERIAL BLOOD
PRESSURE MONITORING

4. Invasive Blood Pressure ( IBP)
 Invasive blood pressure monitors are pressure monitoring systems
Designed to acquire pressure information for display and processing.
This can be used to monitor arterial, central venous, pulmonary artery,
left atrial, right atrial, femoral arterial, umbilical venous, umbilical
arterial and intracranial pressures.

5.  Monitoring beat to beat arterial pressure in
cardiac surgeries.
 In critical care unit
 ABG samples
Indications

6. Basic Principles
 The pressure waveform of the arterial pulse is transmitted via the
Column of fluid to a pressure transducer where it is converted into
an electrical signal.
 This electrical signal is the processed , amplified, and converted
into a visual display by a microprocessor.

7. Meaning
 Insertion of a catheter in artery for direct measurement of systolic ,
diastolic , and mean arterial pressure ( MAP)
 MAP = SBP + ( 2X DBP )
3

8. Equipment and Supplies to be prepared
 Monitor
 Transducer
 Arterial catheter
 Pressure Cable
 Pressure Bag
 Flush: 500 cc NS

10. Leveling
 The pressure transducer must be set at the appropriate level in
relation to the patient in order to measure blood pressure correctly.
 This is usually taken to the level with patient’s heart , at the 4th
intercostal space , in the mid-axillary line
 A transducer too low over reads , a transducer too high under reads.

11. Zeroing
 For a pressure transducer to read accurately , atmospheric pressure
must Be discounted from the pressure measurement.
 This is done by exposing the transducer to atmospheric pressure and
Calibrating the pressure reading to zero.
 A transducer should be zeroed several times per day to eliminate any
Baseline drift.

13. Sites for insertion of catheters
 Radial artery
 Ulnar artery
 Femoral artery
 Dorsalis pedis artery
 Brachial artery
 Axillary artery

16. Complications
 Infections
 Dislodgement
 Dissection
 Thrombosis
 Vascular Compromise
 Displacement of cannula

17. Normal arterial pressure waveforms
o The systolic waveform component consist a steep pressure upstroke ,
peak and ensuing decline and immediately follow the ECG R wave.
o The downslope of the arterial pressure waveform is interrupted by the
dicrotic notch . Continues its decline during diastole after ECG T wave ,
and reaches at end-diastole.
o As the pressure wave travels from the central aorta to the periphery ,
the Arterial upstroke becomes steeper, the systolic peak increases , the
dicrotic notch Appears later ,the diastolic wave becomes more
prominent , and end-diastolic Pressure decreases.

20. Abnormal arterial pressure waveforms
 Morphologic features of individual arterial pressure waveforms can
provide important diagnostic information.

22. Waveform analysis for prediction of intravascular
Volume responsiveness
 Variations in arterial blood pressure observed during positive pressure
Ventilation , as well as a variety of derived indices ,are the most widely
Studied of these dynamic indicators.
 They result from changes in thoracic pressure and lung volume
that occur during the respiratory cycle

24. CENTRAL VENOUS PRESSURE MONITORING

25. Introduction
Central venous pressure measurement is often associated with intensive
And critical care setting. However , with increasing numbers of critically
ill patients being cares for a medical and surgical wards, it is essential
that clinicians are able to record central venous pressure measurement
accurately and recognize normal and abnormal parameters.

26. INDICATION FOR CVP MONITORING
 Patients with hypotension who are not responding to
basic clinical management.
 Continuing hypovolemia secondary to major fluid
shifts or loss.
 Patient requiring infusions of inotropes.
Central Venous pressure assesses…
 Intravascular volume status
 Right ventricular function
 Patient response to drugs &/or fluids

27. Reason for measuring CVP
 Circulating blood flows into the right atrium via the inferior
and superior vena cava. The pressure in the right atrium is known
as central venous Pressure ( CVP)
 Normal values = 2 – 8 mmhg
 Low CVP = hypovolaemia or decrease venous return
 High CVP = over hydration , increase venous return, or right-sided
Heart failure.

28. SITES FOR INSERTION OF CVP CATHETERS
 Subclavian vein
 Internal or external jugular vein
 Median basilica vein
 Femoral vein

29. Measurement of CVP
The transducer is fixed at the level of the right atrium and connected to the
patient ‘s CVP catheter via fluid filled extension tubing.
 More care should be taken to avoid bubbles and kinks .
The transducer is then “zeroed” to atmospheric pressure by turning its 3-way tap
so that is open to the transducer and to the room air ,but closed to the patient.
 The 3-way tap is then turned so that it is now closed to room air and open
between the patient and the transducer.

30. Leveling and Zeroing
 Leveling
 Before /After insertion
 After patient’s bed or transducer move.
 Aligns transducer with catheter tip.
 Zeroing
 Performed before insertion & readings
 Level and zero transducer at the
phlebostatic axis

31. PHLEBOSTATIC AXIS
 The approximate anatomic location of the right atrium, located
At the fourth intercostal space, halfway between the anterior and
Posterior chest wall.
 The purpose of leveling is to line up the air fluid interface with
Left atrium to correct for changes in hydrostatic pressure in blood
Vessels above and below the level of the heart.

32. More on Leveling & Zeroing
 HOB 0 – 60 Degrees
 No lateral positioning
 Phlebostatic axis with any position (dotted line)

33. LEVELLING
PLACEMENT OF THE TRANSDUCER AT THE EXACT HEIGHT OF THE
PHLEBOSTATIC AXIS IS LEVELLING. WHY?
 To eliminate effects of hydrostatic pressure in the transducer.
WHEN TO LEVEL ?
 Level before and after the pressure system is attached to the patient.
 After any change in bed height / patient position
 Change in waveforms and its values.
 When the system is disconnected.
 At the beginning of each shift.

34. TRANSDUCER
 The transducer is a devise that converts the pressure waves
generated by vascular blood flow into electrical signals that can be
displayed on electronic monitoring equipment.
 The transducer cable attaches the transducer to the monitor, which
displays a pressure waveform and numeric readout.

35. ZEROING
ZEROING IS DONE SO AS TO ELIMINATE THE EFFECT OF ATMOSPHERIC
PRESSURE ON THE TRANSDUCER, USING ZERO TO REPRESENT THE CURRENT
ATMOSPHERIC PRESSURE.
 It is required to negate the effects of the atmospheric pressure.
 Done before and after the pressure system is attached to the patient.
 When significant change in waveforms and values is noted.
 When the system is disconnected.
 At the beginning of each shift.

36. PROCEDURE
 Pre-procedure Preparation by an anesthesia technician
or technologist ( monitoring set up)
 Assemble all the equipment
 Prepare a transducer kit
 Explain the procedure to the patient & ensure informed
consent is obtained
 Maintain proper position, draping
 Skin preparation
 Ask for any history of allergies
 Local anesthesia before procedure
 Monitor Lab values( PT/PTT/HB/CBC)
 Post procedure chest X-ray

37. CVP CATHETER

40. DURING PROCEDURE
 Monitor Vitals Signs
 Monitor the waves , ECG
 Attach transducer kit &check the wave form
 Monitor the CVP

41. Factors Affecting CVP
 Factors that increase CVP includes
 Hypervolemia
 Forced exhalation
 Tension pneumothorax
 Heart failure
 Pleural effusion
 Decreased cardiac output
 Cardiac Temponade
 Mechanical ventilation and the application of PEEP ventilation mode.
 Pulmonary Hypertension
 Pulmonary Embolism

42. Care of patient with central line
 Assessment
 Patency
 Monitor CVP in every shift (normal CVP 2- 8mmhg or 5 – 10 cm
water
 Change of dressing
 Maintain pressure
 Documentation
Complications
 Dislodgement of central venous catheter
Infections
Hematoma

43. Relative contraindication
 Coagulopathies and bleeding disorder (monitor platelet count,PT,PTT )
 Current or recent use of fibrinolytics or anticoagulants.
 Insertion sites that are infected or burned, or where previous vascular
Surgery has been performed, or involve catheter placement through
vascular grafts.
 Patients with high risk of pneumothorax such as those with COPD
or those on mechanical ventilation with high PEEP or CPAP .
 Patient with suspected or confirmed vena cava injury.

44. System Maintenance
 Change tubing and fluid bag q 96 hours
No pressures through CVP port
Antibiotics,NS boluses, blood, IV pushes are allowed through the
CVP line
Trouble Shouting
 Damped wave forms
 Pressure bag inflated to 300 mmhg
Reposition extremity or patient
Verify appropriate scale
 Flush or aspirate line
 check or replace module or cable
 Inability to obtain zero wave form
 Connections between cable and monitor
Position of stopcocks
 Retry zeroing after above adjustments.

45. References
1- MILLER’S 8 edition
2- Physical principles of intra-arterial blood pressure measurement
anesthesia
3- Kaplan’s cardiac anesthesia the eco era 6 edition
4 – Scheer B,Perel A ,Pfeiffer UJ,Clinical Review: complication and risk
factors of peripheral arterial catheters used for hemodynamic monitoring
in anesthesia and intensive care medicine.cri.care.2002 jun,6(3):199-204
EPub 2002 apr18.review.pubmed MID : 12133178 PubMed PMID:12133178
PubMed central.PMCID:PMC 137445
5 – Web Resources

46. THANK YOU