Vascular Access and Monitoring Flashcards
A central venous catheter is inserted until the top resides where?
Just outside the right atrium and superior vena cava.
Which port on a CVC is used to monitor a patients CVP?
Use the distal port because it is the closest to the heart.
List types of CVC’s.
Tunneled, non-tunneled, implanted device (or port), and peripherally inserted central catheter.
List indications for central venous catheter placement.
Long term access, difficult access, hemodynamic monitoring, dialysis, administration of caustic medications, introduction of a transvenous pacemaker, and parental nutrition.
What are the three sites for CVC insertion?
Subclavian, internal jugular, femoral.
Following insertion of ALL CVCs a CXR (chest x-ray) is required?
NO. Subclavian and external jugulars need an x-ray, but femoral does not (couldn’t see it on chest x-ray anyways).
The gauge of the distal port on a non-tunneled CVC is?
Usually is a 16gauge. The other ports will be 18g if it’s a triple lumen.
Monitoring the CVP requires the transducer to be levelled at the what?
The phlebostatic axis.
List complications of CVCs.
Hematoma, infections, wrong placement, pneumothorax, air embolus, or loss of a guide wire.
List 2 indications to perform blood sampling via radial artery puncture.
Accessing patients current status, acid/base balance, confirm treatment plan, and to evaluate your current interventions.
List contraindications for radial arterial sampling.
A failed Allen’s test, trauma or burn to the site, to many attempts at the site, previous surgery, graft, or fistulas.
What volume of blood is required for your ABG sample via arterial puncture?
1 mL
What angle do you hold the needle at for arterial puncture?
30 to 45 degrees
What are indications for an arterial line?
Frequent lab testing including ABG’s, monitoring SPO2 and CO2 levels in patients with respiratory problems, the need for accurate continuous blood pressure monitoring, and can also be used in conjunction with ICP monitoring.
What are some complications related to arterial monitoring?
Pain, hematoma, hemorrhage, artery laceration and injury, arterial vasospasm, pseudoaneurysm formation, arteriovenous fistula, infection, limb ischemia, thrombosis/embolism, and nerve damage/neuropathy.
What sites can be used for an arterial line?
Radial, femoral, brachial, dorsalis pedis
Where do you level to for arterial lines?
To the phlebostatic axis (just like central venous lines). The patient needs to be supine but the head can be elevated up to 30 degrees.
What is the external landmark for the right atrium?
The phlebostatic axis which is landmarked using the 4th intercostal space at mid axillary line. Levelling the transducer to this point helps correct for hydrostatic pressure changes in vessels above and below the heart.
What happens to the readings if the transducer isn’t properly leveled?
The readings will be falsely low if leveled above the phlebostatic axis, and the readings will be falsely high if leveled below the phlebostatic axis.
What is the most essential aspect of caring for a patient with an arterial line?
Ensuring accurate and proper functioning of the system. The system must be accurately zeroed and leveled. This must be done with each patient movement, and if working flights, you’ll also have to zero with any altitude changes.
How does intra-arterial monitoring work?
An arterial catheter is inserted (obviously the catheter is hollow), pressures are transmitted to a transducer that converts the pressure to an electric signal which is then amplified and displayed as a wave form and numerical value.
What size of bag is normally used for a hemodynamic monitoring system? At what pressure/flow?
A 500mL bag of normal saline pumped up with a pressure infuser to green zone (300mmHg) which gives you a continuous flow of about 3mL/hr.
What is a dynamic response test (aka square wave test)?
It determines to what degree a system is dampened and so if adjustments need to be made. These results can either be optimally dampened (1.5 oscillations), over dampened (<1.5 oscillations), or under dampened (>1.5 oscillations).
What happens in an under dampened system? Causes?
It can overestimate the systolic and underestimate the diastolic pressures. It can be caused when tubing is too long or too small of bore (increases resistance). Also check for bubbles.
What happens in an over dampened system? Causes?
It can underestimate the systolic and overestimate the diastolic pressures. Can be caused by air bubbles, a kinked catheter, blood clots in the catheter, tubing that is too short or incorrect type, a loose connection, and either no fluid in the flush bag or it is not pressured up.
In an arterial wave form, what does the dicrotic notch indicate?
It is due to closer of the aortic valve and so marks the end of systole and the start of diastole.
If you are monitoring a patient and see a sudden change in arterial waveform from the noted trend, what do you do?
You need to investigate and so reassess your patient. Has their mentation changed? Is there a problem with the equipment or connections? What’s the blood pressure? Etc.
Your patient has an arterial line. How do you approach and assess the line?
Note the location and how it is secured. Assess the site for redness, drainage, or swelling and check for circulation (cap refill, hand warmth). Verify you have the correct tubing attached to a transducer with a 500mL bag of normal saline pressured up to 300mmHg. Is the system zeroed and levelled? Then assess the waveform and do a square wave test. Compare the arterial blood pressure to a non-invasive pressure.
How do you properly take an arterial blood sample?
Clean the port to be used on the 3 way stop cock with an alcohol swab. Turn on the syringe port and withdraw 3mL of blood with a waste syringe so that a pure arterial blood sample is pulled up into the tubing. Then use your arterial blood draw syringe to draw up a 1mL sample. Clear the blood from the line by first flushing the port by turning off the 3 way to the patient and using a waste syringe to withdraw saline from the system to clear the port. Then turn off the syringe port thus opening the system back up to the patient and intermittently flush the remaining blood in order to ensure you don’t cause any ischemia during the procedure. Once done, recheck the site and ensure there is still good perfusion.
What needs to be done with your arterial line post insertion prior to taking any reading?
Leveling to the phlebostatic axis and zeroing it.
