Transducer System Setup and Zeroing
Learn more about Clinical Skills today! Standardize education and management competency among nurses, therapists and other health professionals to ensure knowledge and skills are current and reflect best practices and the latest clinical guidelines.
The transducer system must be leveled and zeroed to provide accurate hemodynamic values.
Route tubes and catheters having different purposes in different, standardized directions (e.g., IV lines routed toward the head; enteric lines toward the feet).undefined#ref4">4
Transducer systems provide a catheter-to-monitor interface so intravascular and intracardiac pressure can be measured. The transducer detects a biophysical event and converts it to an electronic signal.
Fluid-filled pressure monitoring systems used for bedside hemodynamic pressure monitoring are based on the principle that a change in pressure at any point in an unobstructed system results in similar pressure changes at all other points in the system.
Intravascular and intracardiac pressure transducers detect the pressure generated in various areas of the cardiovascular system and convert that pressure wave into an electrical signal, which is transmitted to the monitoring equipment for representation as a waveform on the oscilloscope. Invasive measurement of intravascular pressure requires insertion of a catheter into a central vein or an artery. Invasive measurement of intracardiac (right atrial [RA] and pulmonary artery [PA]) pressure requires insertion of a catheter into the PA.
A single-pressure transducer system is used to measure pressure from a single catheter (e.g., arterial or central venous) (Figure 1). A double-pressure transducer system is used to measure pressure from two catheters (e.g., arterial and central venous) or two ports (e.g., PA and RA) from a single catheter (e.g., PA catheter) (Figure 2). A triple-pressure transducer system is commonly used to measure pressure from the arterial and PA catheters (Figure 3). With this system, arterial pressure, PA pressure, and RA pressure can be obtained. All hemodynamic values (PA, RA, and arterial) are referenced to the level of the atria. The external reference point of the atria is the phlebostatic axis.
Labeling the tubing reduces the chance of misconnection, especially in circumstances where multiple IV lines or devices are in use.3
See Supplies tab at the top of the page.
Rationale: The decision to use heparin should be based on the clinical risk of occlusion and patient factors, such as heparin sensitivities.2
Although heparin may prevent thrombosis, it has been associated with thrombocytopenia and other hematologic complications. A heparinized 0.9% sodium chloride solution for the flush bag comes as a premixed solution. Ensure that the solution contains the correct strength of heparin before hanging it.
Rationale: The label indicates when the flush bag needs to be changed.
Rationale: Evacuating air from the flush bag prevents air from being flushed to the patient if the bag runs out of 0.9% sodium chloride solution. Filling the drip chamber halfway prevents air bubbles from entering the tubing and allows the nurse to see that the solution is flowing during a manual flush of the invasive line.
Rationale: Priming the tubing under pressure increases turbulence and may cause air bubbles to enter the tubing.
Never allow air in a hemodynamic system. Air microemboli or macroemboli can migrate to major organs and present a potentially life-threatening complication.
Rationale: Flushing eliminates air from the system.
Rationale: The manufacturer places vented caps to permit sterilization of the entire system. Replacing the vented cap with a nonvented cap prevents bacteria and air from entering the system.
Rationale: Inflating the pressure bag to 300 mm Hg allows 3 ml/hr of flush solution to be delivered through the catheter, thus maintaining catheter patency and minimizing clot formation.5
Rationale: Waveforms vary in amplitude depending on the pressure in the system and the pressure wave being monitored. Scales may vary based on monitoring equipment and may be adjusted based on the patient’s pressure levels.
Rationale: Removing the cap allows the monitor to use atmospheric pressure as a reference for zero.
Rationale: Zeroing negates the effects of atmospheric pressure.
Rationale: Turning the stopcock permits pressure monitoring and maintains catheter patency.
Rationale: The fast-flush square wave test helps determine whether the transducer system is accurately reproducing the hemodynamic pressure and waveforms.
Rationale: Checking the solution level helps ensure catheter patency.
Rationale: A pressure level of 300 mm Hg maintains catheter patency.
Rationale: Checking the system ensures system integrity, safety, and accuracy. A crack or loss of integrity in the transducer can result in inaccurate hemodynamic readings.
Adapted from Johnson, K.L. (Ed.). (2024). AACN procedure manual for progressive and critical care (8th ed.). St. Louis: Elsevier.
Clinical Review: Joyce Foresman-Capuzzi, DNP, RN, CCNS, CEN, CPEN, CTRN, TCRN, CPN, CCRN, AFN-BC, SANE-A, GERO-BC, NPD-BC, EBP-C, NHDP-BC, EMT-P, FAEN
Published: January 2024
Cookies are used by this site. To decline or learn more, visit our cookie notice.
Copyright © 2024 Elsevier, its licensors, and contributors. All rights are reserved, including those for text and data mining, AI training, and similar technologies.