Pulmonary Artery Pressure Measurement

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Pulmonary Artery Pressure Measurement

• Issued May 2004

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Lecture Content

• Patient Positioning
• Identify Phelbostatic Axis
• Leveling
• Square Wave Test
• Obtain PA Reading

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Patient Positioning

• Supine
• Head of bed 0-60

Angels 45º 30º 0º
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Leveling

• Eliminates effects of hydrostatic forces on the
  observed hemodynamic pressures
• Ensure air-fluid interface of the transducer is
  leveled before zeroing and/or obtaining pressure
  readings
• Phlebostatic axis
• Level of left atrium
• 4th ICS ½ AP diameter
• Mark the chest with washable felt pen

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Identify Phlebostatic Axis
Intersection of the 4th ICS and ½ the
anterior-posterior diameter of the chest
McHale DL, Carlson KK. AACN Procedure Manual for
Critical Care 4th ed WB Saunders Philadelphia,
Pa 2001 (479) With permission from Elsevier
6
Mark location chest wall with washable felt pen
Used with permission of PACEP Collaborative
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Level Transducer System
Ensure air-fluid interface of the transducer is
level to phelbostatic axis.
Used with permission of PACEP Collaborative
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Level Transducer System

• Relevel the transducer with any
• change in the patients position
• Referencing the system 1 cm
• above the left atrium decreases
• the pressure by 0.73 mm Hg
• Referencing the system 1 cm
• below the left atrium increases
• the pressure by 0.73 mm Hg

Angels 45º 30º 0º
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Square Wave Test

• Determines the ability of the
• transducer to correctly reflect
• pressures
• Perform at the beginning of
• each shift

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Square Wave Test
Figure A Expected square wave test
Figure B Over damped
Reprinted from Darovic GO. Hemodynamic
Monitoring Invasive and Noninvasive Clinical
Application 2nd ed. Philadelphia,Pa WB Saunders
Co1995161-162 Used with permission from Elsevier
Figure C Under damped
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Under Damped System

• Over responsive,
• exaggerated, artificially
• spiked waveform
• SBP erroneously high
• DBP erroneously low
• Causes small air
• bubbles, too long of
• tubing, defective
• transducer

Reprinted from Darovic GO. Hemodynamic
Monitoring Invasive and Noninvasive Clinical
Application 2nd ed. Philadelphia,Pa WB Saunders
Co1995161-162 Used with permission from Elsevier
12
Over Damped System

• Sluggish, artificially
• rounded blunted
• appearance
• SBP erroneously low
• DBP erroneously high
• Causes large air
• bubbles in system,
• compliant tubing,
• loose/open connections,
• low fluid level in flush bag

Reprinted from Darovic GO. Hemodynamic
Monitoring Invasive and Noninvasive Clinical
Application 2nd ed. Philadelphia,Pa WB Saunders
Co1995161-162 Used with permission from Elsevier
13
PAP Documentation

• Measure at end expiration
• Measure pressures from a graphic tracing
• Measure pulmonary capillary wedge pressure at
  end-expiration using the mean of the a wave
• a wave indicates atrial contraction and falls
  
• within the P QRS interval of the
  corresponding
• ECG complex

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Respiratory Component

• Changes in intrathoracic pressure
• during respiration change PAP
• readings
• Record and trend pressure readings at end
  expiration

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Used with permission of PACEP Collaborative
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Used with permission of PACEP Collaborative
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Used with permission of PACEP Collaborative
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Respiratory Variation
Spontaneous ventilation
Mechanical ventilation
Aherns TS, Taylor LK. Hemodynamic Waveform
Analysis. Philadelphia, Pa WB Saunders 1992
27 Used with permission from Elsevier
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Used with permission of PACEP Collaborative
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Used with permission of PACEP Collaborative
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Used with permission of PACEP Collaborative
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Used with permission of PACEP Collaborative
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Need Further Assistance?
For more information or further assistance,
please contact a clinical practice specialist
with the AACN Practice Resource Network.
Email practice_at_aacn.org Phone [phone],
x217