FMP Hemodynamics/Monitoring – Qs And As
Arterial Line (A-line) overview ✔️Ans - Thin catheter inserted into an
artery (commonly the radial) in order to monitor blood pressure and mean
arterial pressure in real time. This catheter is more firm than an
intravenous line (IV).
-Also used for collection of arterial blood gas (ABG)
-Displayed as a red waveform usually near the bottom on the monitor
Direct, accurate, and continuous display of blood pressure, useful when
titrating vasoactive or antihypertensive infusions
Can serve as an alternative trigger source for IABP timing
Arterial Line setup ✔️Ans - Consider performing the Allen test prior to
placement
-Occlude radial and ulnar arteries with three fingers. Have patient
clench/unclench fist x10. Palm and fingers should be blanched. Release
arteries and assess time for palm and fingers to become flushed with blood.
If the capillary refill time is less than 6 seconds the test is considered
positive, suggesting good arterial blood flow and indicating the artery is
suitable for cannulation.
Spike pressure bag and prime rigid tubing to pressure of 300mmHg.
-Be sure to bleed air all the way through stopcock
Once cannulation is performed, connect catheter to primed rigid tubing
and pressure-monitoring transducer
Leveling the transducer ✔️Ans - Most common cause of error is
incorrect leveling of the transducer
1) Patient position = 0-60 degrees HOB
2) Phlebostatic axis (reference point for zeroing hemodynamic monitoring
device, helps to ensure the accuracy of the various pressure readings) - 4th
ICS, midaxillary, approx. level of L atrium
,3) Mark point on patient's chest (~2 mm Hg ERROR FOR EVERY INCH
MISALIGNED)
4) Secure transducer to patient at phlebostatic axis. Place 4x4s over
marked point, and then tape transducer directly over
Zeroing arterial line ✔️Ans - 1. The spot where the zeroing takes place is
at the transducer (shown by the above image). Start by turning the
stopcock (white part of the transducer) off to the patient. In the picture,
this would be turning the stop cock 90 degrees to the left. This blocks air
from getting into the patient while zeroing.
2. Next, take off the cap on the transducer (the clear cap behind the stop
cock). Some of these already have holes in them which would mean that
you don't have to take it off. Make sure to keep line sterile.
3. Press the "zero" button on your monitor. Wait for it to zero the line.
4. Place the clear cap back on the transducer.
5. Turn the stop cock back upwards (in the picture above, it would be
turning it 90 degrees to the right). This allows the pressure line to actually
monitor the pressure (BP or CVP)...and you're done!
Arterial waveform ✔️Ans - Diastolic pressure: Lowest point of waveform
Systolic pressure: Highest point of waveform
Dicrotic notch: Point at which aortic valve closes, small notch in waveform
following peak. Transition from systolic to diastolic phase Slur in this part
of the waveform may indicate aortic valve stenosis.
Diastolic decay curve: Gradual downslope until lowest point is reached,
represents gradual decrease in pressure between systole and diastole
"Rule of 3s" for Arterial Lines ✔️Ans - Pressure bag must have
300mmHg pressure
, Fluid delivered through art line to maintain patency/prevent clotting at
3mL/hr
Flick test should produce no more than 3 oscillations, and flick test should
be performed for no more than 3 seconds
Transducer Overdampening ✔️Ans - Overdampening: system is not
dynamic, too much pressure on artery makes arterial pressure appear
artificially low
-In addition to waveform changes, look for disparity between NIBP and
arterial pressure
"Overdamping = Obstruction"
-Kinked line
-Obstruction/air in the tube
-Pressure bag overfilled or overpressurized
Transducer Underdampening ✔️Ans - Underdampening: system is too
dynamic, not enough pressure on artery makes arterial pressure appear
artificially high
-In addition to waveform changes, look for disparity between NIBP and
arterial pressure
Common causes:
-Pressure bag not full/leak in line
-Hypothermia
-Catheter whip/movement
Transducer Flick Test ✔️Ans - PROCEDURE:
Give fast flush of fluid through line for no more than 3 seconds
There should be no more than 3 oscillations following flush
For each oscillation, the amplitude should be no greater than 1/3rd of the
previous oscillation
INTERPRETATION:
No oscillations
-Overdampening
Arterial Line (A-line) overview ✔️Ans - Thin catheter inserted into an
artery (commonly the radial) in order to monitor blood pressure and mean
arterial pressure in real time. This catheter is more firm than an
intravenous line (IV).
-Also used for collection of arterial blood gas (ABG)
-Displayed as a red waveform usually near the bottom on the monitor
Direct, accurate, and continuous display of blood pressure, useful when
titrating vasoactive or antihypertensive infusions
Can serve as an alternative trigger source for IABP timing
Arterial Line setup ✔️Ans - Consider performing the Allen test prior to
placement
-Occlude radial and ulnar arteries with three fingers. Have patient
clench/unclench fist x10. Palm and fingers should be blanched. Release
arteries and assess time for palm and fingers to become flushed with blood.
If the capillary refill time is less than 6 seconds the test is considered
positive, suggesting good arterial blood flow and indicating the artery is
suitable for cannulation.
Spike pressure bag and prime rigid tubing to pressure of 300mmHg.
-Be sure to bleed air all the way through stopcock
Once cannulation is performed, connect catheter to primed rigid tubing
and pressure-monitoring transducer
Leveling the transducer ✔️Ans - Most common cause of error is
incorrect leveling of the transducer
1) Patient position = 0-60 degrees HOB
2) Phlebostatic axis (reference point for zeroing hemodynamic monitoring
device, helps to ensure the accuracy of the various pressure readings) - 4th
ICS, midaxillary, approx. level of L atrium
,3) Mark point on patient's chest (~2 mm Hg ERROR FOR EVERY INCH
MISALIGNED)
4) Secure transducer to patient at phlebostatic axis. Place 4x4s over
marked point, and then tape transducer directly over
Zeroing arterial line ✔️Ans - 1. The spot where the zeroing takes place is
at the transducer (shown by the above image). Start by turning the
stopcock (white part of the transducer) off to the patient. In the picture,
this would be turning the stop cock 90 degrees to the left. This blocks air
from getting into the patient while zeroing.
2. Next, take off the cap on the transducer (the clear cap behind the stop
cock). Some of these already have holes in them which would mean that
you don't have to take it off. Make sure to keep line sterile.
3. Press the "zero" button on your monitor. Wait for it to zero the line.
4. Place the clear cap back on the transducer.
5. Turn the stop cock back upwards (in the picture above, it would be
turning it 90 degrees to the right). This allows the pressure line to actually
monitor the pressure (BP or CVP)...and you're done!
Arterial waveform ✔️Ans - Diastolic pressure: Lowest point of waveform
Systolic pressure: Highest point of waveform
Dicrotic notch: Point at which aortic valve closes, small notch in waveform
following peak. Transition from systolic to diastolic phase Slur in this part
of the waveform may indicate aortic valve stenosis.
Diastolic decay curve: Gradual downslope until lowest point is reached,
represents gradual decrease in pressure between systole and diastole
"Rule of 3s" for Arterial Lines ✔️Ans - Pressure bag must have
300mmHg pressure
, Fluid delivered through art line to maintain patency/prevent clotting at
3mL/hr
Flick test should produce no more than 3 oscillations, and flick test should
be performed for no more than 3 seconds
Transducer Overdampening ✔️Ans - Overdampening: system is not
dynamic, too much pressure on artery makes arterial pressure appear
artificially low
-In addition to waveform changes, look for disparity between NIBP and
arterial pressure
"Overdamping = Obstruction"
-Kinked line
-Obstruction/air in the tube
-Pressure bag overfilled or overpressurized
Transducer Underdampening ✔️Ans - Underdampening: system is too
dynamic, not enough pressure on artery makes arterial pressure appear
artificially high
-In addition to waveform changes, look for disparity between NIBP and
arterial pressure
Common causes:
-Pressure bag not full/leak in line
-Hypothermia
-Catheter whip/movement
Transducer Flick Test ✔️Ans - PROCEDURE:
Give fast flush of fluid through line for no more than 3 seconds
There should be no more than 3 oscillations following flush
For each oscillation, the amplitude should be no greater than 1/3rd of the
previous oscillation
INTERPRETATION:
No oscillations
-Overdampening
