Pulmonary Artery Catheter Insertion (Assist) and Pressure Monitoring

Transcription

1 PROCEDURE 72 Pulmonary Artery Catheter Insertion (Assist) and Pressure Monitoring Reba McVay PURPOSE: Pulmonary artery (PA) catheters are used to determine hemodynamic status in critically ill patients. PA catheters provide information about right-sided and left-sided intracardiac pressures and cardiac output. Additional functions available are fi beroptic monitoring of mixed venous oxygen saturation, intracardiac pacing, and assessment of right-ventricular volumes and ejection fraction. Hemodynamic information obtained with a PA catheter is used to aid diagnosis and guide therapeutic intervention, including administration of fl uids and diuretics and titration of vasoactive and inotropic medications. PREREQUISITE NURSING KNOWLEDGE Knowledge of the normal cardiovascular and pulmonary anatomy and physiology is needed. Knowledge of principles of aseptic technique is essential. Basic dysrhythmia recognition and treatment of lifethreatening dysrhythmias should be understood. Advanced cardiac life support (ACLS) knowledge and skills are needed. Knowledge of the components of the PA catheter ( Fig ) and the location of the PA catheter in the heart and PA (Fig ) is necessary. Knowledge of the setup of the hemodynamic monitoring system (see Procedure 75 ) is needed. Understanding of normal hemodynamic values (see Table 64-1 ) is essential. The PA catheter contains a proximal injectate lumen port, a PA distal lumen port, a thermistor connector, and a balloon-inflation port with valve. Some catheters also have two infusion ports, right atrial (RA) and right ventricular (RV) lumens that can be used for infusion of medications and intravenous fluids. The PA distal lumen is used to monitor systolic, diastolic, and mean pressures in the PA. This lumen also allows for sampling of mixed venous blood. The proximal injectate lumen is used to monitor the RA pressure and inject the solution used to obtain cardiac output (CO). The ballooninflation port is used to advance the PA catheter tip to the wedge position and measure the pulmonary artery occlusion pressure (PAOP). PAOP may be referred to as pulmonary artery wedge pressure or the pulmonary capillary wedge pressure. The PA diastolic pressure and the PAOP are indirect measures of left ventricular (LV) end-diastolic pressure. Usually, the PAOP is approximately 1 to 4 mm Hg less than the pulmonary artery diastolic pressure (PADP). Because these two pressures are similar, the PADP is commonly followed, which minimizes the frequency of balloon inflation, thus decreasing the potential of balloon rupture and PA trauma. Differences between the PADP and the PAOP may exist for patients with pulmonary hypertension, chronic obstructive lung disease, acute respiratory distress syndrome, pulmonary embolus, and tachycardia. See Procedure 71 for common indications for insertion of a PA catheter. Hemodynamic monitoring with a PA catheter has no absolute contraindications, but an assessment of risk versus benefit to the patient should be considered. Relative contraindications to PA catheter insertion include presence of fever, presence of a mechanical tricuspid valve, presence of an endocardial pacemaker, and a coagulopathic state. A patient with left bundle-branch block may have a right bundle-branch block develop during PA catheter insertion, resulting in complete heart block. In these patients, a temporary pacemaker should be readily available. PA pressures may be elevated as a result of PA hypertension, pulmonary disease, mitral valve disease, LV failure, atrial or ventricular left-to-right shunt, pulmonary emboli, or hypervolemia. PA pressures may be low due to hypovolemia or low pulmonary vascular resistance (e.g., vasodilation). Transduced waveforms that are viewable during insertion include RA, RV, PA, and PA occlusion (PAO; Figs and 72-3 ). The RA and PAO waveforms have a, c, and v waves: The a wave reflects atrial contraction, the c wave reflects closure of the atrioventricular valve, and the v wave reflects passive filling of the atria during ventricular systole (Figs and 72-5 ). 609

2 610 Unit II Cardiovascular System Figure 72-1 Anatomy of the pulmonary artery (PA) catheter. The standard 7.5-Fr thermodilution PA catheter is 110 cm in length and contains four lumens. It is constructed of radiopaque polyvinyl chloride. Black markings are on the catheter in 10-cm increments beginning at the distal end. At the distal end of the catheter is a latex rubber balloon of 1.5-mL capacity, which, when inflated, extends slightly beyond the tip of the catheter without obstructing it. Balloon inflation cushions the tip of the catheter and prevents contact with the right-ventricular wall during insertion. The balloon also acts to float the catheter into position and allows measurement of the pulmonary artery occlusion pressure. The narrow black bands represent 10-cm lengths, and the wide black bands indicate 50-cm lengths. (From Visalli F, Evans P: The Swan-Ganz catheter: A program for teaching safe effective use, Nursing 81[11]:1, 1981.) Figure 72-2 Pulmonary artery (PA) catheter location within the heart. Pulmonary artery occlusion pressure (PAOP) is an indirect measure of left-atrial (LA) and left-ventricular (LV) end-diastolic pressure. Pulmonary artery occlusion pressure (PAOP) is also referred to as pulmonary artery wedge pressure (PAWP). (From Kersten LD: Comprehensive respiratory nursing, Philadelphia, 1989, Saunders.)

3 72 Pulmonary Artery Catheter Insertion (Assist) and Pressure Monitoring 611 Figure 72-3 Schematic of waveform progression as a pulmonary artery (PA) catheter is inserted through the various cardiac chambers. (From Abbott Critical Care Systems, Mountain View, CA.) Figure 72-4 Identification of a, c, and v waves in the waveform for right-atrial and central venous pressure. Atrial waveforms are characterized by three components: a, c, and v waves. The a wave reflects atrial contraction, the c wave reflects closure of the tricuspid valve, and the v wave reflects passive filling of the atria. (From Ahrens TS, Taylor LK: Hemodynamic waveform analysis, Philadelphia, 1992, Saunders.) The a wave reflects ventricular filling at end diastole. The mean of the a wave is determined by averaging the top and bottom values of the a wave. Elevated a and v waves may be evident in right atrial pressure (RAP/central venous pressure [CVP]) and in PAOP waveforms. These elevations may occur in patients with cardiac tamponade, constrictive pericardial disease, and hypervolemia. Elevated a waves in the RAP/CVP waveform may occur in patients with pulmonic or tricuspid valve stenosis, RV ischemia or infarction, RV failure, PA hypertension, and atrioventricular (AV) dissociation. Elevated a waves in the PAOP waveform may occur in patients with mitral valve stenosis, acute LV ischemia or infarction, LV failure, and AV dissociation. Elevated v waves in the RAP/CVP waveform may occur in patients with tricuspid valve insufficiency. Elevated v waves in the PAOP waveform may occur in patients with mitral valve insufficiency or a ruptured papillary muscle. Insertion and placement verification should occur as follows: The PA catheter is typically inserted through the subclavian, internal jugular, or femoral veins.

4 612 Unit II Cardiovascular System Figure 72-5 Normal pulmonary artery occlusion pressure (PAOP) waveform. Note the delay in the a, c, and v waves because of the time needed for the mechanical events to show a pressure change. This waveform is from a spontaneously breathing patient. The arrow indicates end expiration, where the mean of a wave pressure is measured. Pulmonary artery occlusion pressure (PAOP) is also referred to as pulmonary artery wedge pressure (PAWP). The standard 7.5 Fr PA catheter is 110 cm long and has black markings at 10-cm increments and wide black markings at 50-cm increments (see Fig ). The catheter should reach the PA after being advanced approximately 40 to 55 cm from the internal jugular vein, 35 to 50 cm from the subclavian vein, and 60 cm from the femoral vein. Verification of PA catheter position is validated with waveform analysis. Correct catheter position shows a PAO waveform when the balloon is inflated and a PA waveform when the balloon is deflated. Confirmation of the PA catheter position is also verified with chest radiography. The PA catheter balloon contains latex, which may cause allergic reactions. Latex-free catheters are available. EQUIPMENT PA catheter (non heparin-coated PA catheters and latexfree PA catheters are available) Percutaneous sheath introducer kit and sterile catheter sleeve Pressure modules and cables for interface with the monitor Cardiac output cable with a thermistor/injectate sensor and/or continuous CO monitor Pressure-transducer system, including flush solution recommended according to institutional standards, a pressure bag or device, pressure tubing with transducers, and flush device (see Procedure 75 ) Dual-channel recorder Sterile normal saline intravenous (IV) solution for flushing of the introducer and catheter infusion ports Antiseptic solution (e.g., 2% chlorhexidine based preparation) Head covers, fluid-shield masks, sterile gowns, sterile gloves, nonsterile gloves, and full sterile drapes 1% lidocaine without epinephrine Sterile basin or cup Sterile water or normal saline solution Sterile dressing supplies Stopcocks (may be included in some pressure-tubing systems) Sterile injectable or noninjectable caps Leveling device (low-intensity laser or carpenter level) Additional equipment, to have available as needed, includes the following: Fluoroscope or ultrasound machine Emergency resuscitation equipment Temporary pacing equipment Indelible marker Transducer holder and IV pole Heparin 3-mL syringe, slip tip and Luer-Lock Chlorhexidine-impregnated sponge PATIENT AND FAMILY EDUCATION Provide the patient and family with information about the PA catheter, the reason for the PA catheter, and an explanation of the equipment. Rationale: The patient and family will understand the procedure, why it is needed, and how it will help manage care. Patient and family anxiety may decrease. Explain the patient s expected participation during the procedure. Rationale: This explanation will encourage patient assistance.

5 72 Pulmonary Artery Catheter Insertion (Assist) and Pressure Monitoring 613 PATIENT ASSESSMENT AND PREPARATION Patient Assessment Determine baseline hemodynamic, cardiovascular, peripheral vascular, and neurovascular status. Rationale: Assessment provides data that can be used for comparison with postinsertion assessment data and hemodynamic values. Determine the patient s baseline pulmonary status. If the patient is mechanically ventilated, note the type of support, ventilator mode, and presence or absence of positive endexpiratory pressure (PEEP) or continuous positive airway pressure. Rationale: The presence of positive pressure mechanical ventilation alters hemodynamic waveforms and pressures. Assess the patient s medical history specifically related to problems with venous access sites, cardiac anatomy, and pulmonary anatomy. Rationale: Identification of obstructions or disease should be made before the insertion attempt. Assess the patient s current laboratory profile, including electrolyte, coagulation, and arterial blood gas results. Rationale: Laboratory abnormalities are identified. Baseline coagulation studies are helpful in determination of the risk for bleeding. Electrolyte and arterial blood gas imbalances may increase cardiac irritability. Patient Preparation Verify that the patient is the correct patient using two identifiers. Rationale: Before performing a procedure, the nurse should ensure the correct identification of the patient for the intended intervention. Ensure that the patient and family understand preprocedural teaching. Answer questions as they arise, and reinforce information as needed. Rationale: Understanding of previously taught information is evaluated and reinforced. Ensure that informed consent has been obtained. Rationale: Informed consent protects the rights of the patient and makes a competent decision possible for the patient. Perform a preprocedure verification and time out. Rationale: Ensures patient safety. Validate the patency of the alternate central or peripheral IV access catheter. Rationale: Access may be needed for administration of emergency medications or fluids. Assist the patient to the supine position. Rationale: This position prepares the patient for skin preparation, catheter insertion, and setup of the sterile field. Sedate the patient and/or give analgesics as prescribed and needed. Rationale: Movement of the patient may inhibit insertion of the PA catheter. Pressure Monitoring Assisting With PA Catheter Insertion 1. HH 2. Prepare the flush solution for the pressure-transducer systems (see Procedure 75 ). A. Use an IV bag of normal saline. B. Follow institutional standards for adding heparin to the IV bag, if heparin is prescribed and not contraindicated. (Level B *) 3. Prime or flush the pressuretransducer systems (see Procedure 75 ). 4. Apply and inflate the pressure bag or device to 300 mm Hg. 5. Connect the pressure cables (RA and PA) to the bedside monitor (see Fig ). Heparinized flush solutions are commonly used to minimize thrombi and fibrin deposits on catheters that might lead to thrombosis or bacterial colonization of the catheter. Removes air bubbles. Air bubbles introduced into the patient s circulation can cause air embolism. Air bubbles within the tubing dampen the waveform. Each flush device delivers 1 3 ml/hr to maintain patency of the hemodynamic system. Connects the pressure-transducer systems to the bedside monitoring system. Although heparin may prevent thrombosis, 24,29 it has been associated with thrombocytopenia and other hematologic complications.5 Further research is needed regarding use of heparin versus normal saline to maintain PA catheter patency. Air is more easily removed from the hemodynamic tubing when the system is not under pressure. * Level B: Well-designed, controlled studies with results that consistently support a specifi c action, intervention, or treatment. Procedure continues on following page

6 614 Unit II Cardiovascular System 6. Set the scales on the bedside monitor for each anticipated pressure waveform. 7. Level the RA (proximal) air-fluid interface (zeroing stopcock) and the PA (distal) air-fluid interface (zeroing stopcock) to the phlebostatic axis (see Figs and 75-9 ). 8. Zero the system connected to the PA (distal) lumen and to the RA (proximal) lumen of the PA catheter by turning the stopcock of each system off to the patient, opening it to air, and zeroing the monitoring system (see Procedure Prepares the bedside monitor. The phlebostatic axis approximates the level of the atria and is the reference point for patients in the supine position. Prepares each monitoring system so that pressures can be obtained during catheter insertion. The scale for the RA/CVP pressure commonly is set at 20 mm Hg, and the PA scale commonly is set at 40 mm Hg. Scale settings may vary based on monitoring equipment. The scales can be adjusted if needed after the PA catheter is inserted based on patient pressures. The reference point for the atria changes when a patient is in the lateral position (see Fig ). 75 ). 9. HH 10. PE All healthcare personnel involved in the procedure need to apply head coverings, fluid-shield masks, and sterile gowns. 11. Assist the physician or advanced practice nurse as needed with opening the packaging of sterile drapes, and opening the PA catheter and introducer kits. 12. When the sheath introducer is in place, connect a normal saline IV solution to the infusion port. 13. Connect the pressure-transducer system to the PA distal and proximal ports of the PA catheter when the physician, advanced practice nurse, or other healthcare professional inserting the PA catheter hands them off to the critical care nurse. Aids in preparing for the procedure. Maintains the patency of the sheath introducer infusion port. Provides assistance in preparing the catheter. 14. Flush the air from the catheter. Removes air from the pulmonary artery catheter. 15. If inserting a PA catheter with the ability to monitor mixed venous oxygenation, the fiberoptics are calibrated before removal from the package (see Procedure 16 ). 16. Observe as the physician or advanced practice nurse wiggles the PA catheter (sometimes called whipping ). Calibrates the system before insertion. The movement of the catheter will be seen on the monitor. This ensures that there are no connection issues or catheter defects before insertion. The patient will be fully draped with exposure of only the insertion site. Flush additional infusion ports and attach sterile injectable or noninjectable caps. Follow manufacturer guidelines for catheter calibration.

7 72 Pulmonary Artery Catheter Insertion (Assist) and Pressure Monitoring The physician or advanced practice nurse will insert the PA catheter through a sterile catheter sleeve (see Procedure 71 ). 18. As insertion begins, continuously monitor and print the electrocardiogram (ECG) and PA distal pressure waveform strip. 19. After the tip of the PA catheter is in the right atrium, inflate the balloon with no more than ml of air and close the gate valve or the stopcock (Fig ). 20. Observe for RA, RV, PA, and then PAO waveforms (see Fig ). 21. Verify that the PA catheter tip is in the proper position. A. When the balloon is deflated, the PA waveform is displayed on the monitor. B. When the balloon is inflated, the PAO waveform is displayed on the monitor. Maintains sterility of the PA catheter to allow repositioning of the catheter. 8 Provides documentation of RA, RV, and PA pressures during insertion and dysrhythmia occurrence during insertion. The inflated balloon helps to advance the PA catheter through the right side of the heart and into the PA, minimizing the chance of endocardial damage. Closing the gate valve or the stopcock holds air in the balloon during insertion. Placement in the PA is validated with waveform analysis. When the balloon is inflated, the catheter floats from the PA to a smaller pulmonary arteriole. Additional research is needed to determine how long the sleeve remains sterile. A dual-channel recorder is preferred so the ECG and the PA waveform can be simultaneously recorded. The presence of the tip of the catheter in the right atrium is determined by observing the waveform (for RA/ CVP waveform with a, c, v waves) from the catheter s distal lumen during insertion (see Fig ). Use the syringe from the PA insertion kit. It will not allow more than 1.5 ml of air to be used. Clearly communicate with the physician, advanced practice nurse, or other healthcare professional inserting the catheter: A. If the provider requests, Inflate the balloon. B. The critical care nurse should respond, Inflating the balloon and Balloon inflated and locked. Monitor the ECG tracing as the PA catheter is inserted because ventricular dysrhythmias may result from RV irritability. RV pressures are obtained only during insertion. The catheter usually reaches the PA after being advanced approximately cm from the internal jugular vein, cm from the subclavian vein, and 60 cm from the femoral vein. Placement may vary depending on patient size. A chest radiograph is obtained to verify catheter position. Procedure continues on following page Sliding gate valve Catheter Arrow aligned indicates open position CLOSED Arrow offset indicates closed position OPEN Gate Valve Operation Figure 72-6 Pulmonary artery catheter gate valve. Top left: Gate valve in the open position. Bottom left: Gate valve in the closed position. (From Baxter Edwards Corporation.)

8 616 Unit II Cardiovascular System 22. After the PA catheter is in place: A. Open the balloon inflation gate valve or stopcock. B. Remove the balloon syringe. 23. Reassess accurate leveling and secure the pressure transducer system (see Procedure 75 ). 24. Zero both the RA and PA pressure transducer systems (see Procedure 75 ). 25. Observe the waveform and perform a dynamic response test (square wave test; see Fig ). 26. Assist if needed with applying an occlusive, sterile dressing to the insertion site (see Procedure 66 ). 27. Connect the thermistor connector of the PA catheter to the CO monitor or module (see Procedure 64 ). 28. Document the external centimeter marking of the PA catheter at the introducer exit site. The gate valve or stopcock is closed during insertion to retain air in the balloon. The air is then passively released so that continuous monitoring of the PA waveform can be performed. Ensures that the air-filled interface (zeroing stopcock) is maintained at the level of the phlebostatic axis. If the air-fluid interface is above the phlebostatic axis, PA pressures are falsely low. If the air-fluid interface is below the phlebostatic axis, PA pressures are falsely high. Allows the monitor to use atmospheric pressure as a reference for zero. Determines whether the system is damped. This will ensure that the pressure waveform components are clearly defined and aids in accurate measurement. Reduces the risk for infection. Allows the core temperature to be monitored and is needed for CO measurement. Identifies the length of the PA catheter inserted and allows for evaluation of PA catheter movement. 29. Set the monitor alarms. Activates the bedside and central alarm system. 30. Remove PE and sterile equipment and discard used supplies in appropriate receptacles. Removes and safely discards used supplies. Air is expelled from the syringe, and the empty syringe is reconnected to the balloon inflation valve port. Clearly communicate with the physician, advanced practice nurse, or other healthcare professional inserting the catheter: A. If the physician, advanced practice nurse, or other healthcare professional requests, Deflate the balloon. B. The critical care nurse should respond, Deflating the balloon and Balloon deflated. Leveling ensures accuracy. The point of the phlebostatic axis should be marked with an indelible marker, especially with use of a pole-mount setup. The square wave test can be performed by activating and quickly releasing the fast flush. A sharp upstroke should terminate in a flat line at the maximal indicator on the monitor. This should be followed by an immediate rapid downstroke extending below baseline with 1 2 oscillations within 0.12 second and a quick return to baseline. Follow institutional standards for application of a chlorhexidineimpregnated sponge (see Procedure 66 ). If the centimeter marking is not visible at the exit site, measure the distance from the introducer exit site to the nearest visible marking. Upper and lower alarm limits are set on the basis of the patient s current clinical status and hemodynamic values.

9 72 Pulmonary Artery Catheter Insertion (Assist) and Pressure Monitoring HH 32. Ensure chest radiograph is Verifies PA catheter positioning. completed. Obtaining PA Pressure Measurements RA/CVP 1. Position the patient in the supine position with the head of the bed from 0 to 45 degrees. (Level B * ) 2. Run a dual-channel strip of the ECG and RA waveform (Fig ). 3. Measure RA pressure at end expiration. Studies have determined that the RA and PA pressures are accurate in this position. 3,6,7,10,18,20,22,34,35 RA pressures should be measured from the graphic strip because the effect of ventilation can be identified. The effects of intrathoracic pressure on the RAP is minimized at the end-expiration phase of the respiratory cycle. RA and PA pressures may be accurate for patients in the supine position with the head of the bed elevated up to 60 degrees, 7,22 but additional studies are needed to support this. Only one study 19 supports the accuracy of hemodynamic values for patients in the lateral positions; other studies do not. 3,13,18,26,34 The majority of studies support the accuracy of hemodynamic monitoring for patients in the prone position. 1,2,12,17,21,27,32 Two studies demonstrated that prone positioning caused an increase in hemodynamic values. 28,31 The digital monitor data can be used to measure RA pressure if ventilation does not cause respiratory variation of the RA pressure waveform. Some monitors have the capability of freeze framing waveforms. A cursor can be used to measure pressure measurements. *Level B: Well-designed, controlled studies with results that consistently support a specifi c action, intervention, or treatment. Procedure continues on following page Figure 72-7 Note vertical lines drawn from the beginning of the P wave of two of the electrocardiogram complexes down to the right atrial (RA) waveform. The first positive deflection of the RA waveform is the a wave; the second positive deflection is the v wave. The c wave, which would lie between the a wave and the v wave, is not evident in this strip. CVP, central venous pressure.

10 618 Unit II Cardiovascular System 4. With the dual-channel recorded strip, draw a vertical line from the beginning of the P wave of one of the ECG complexes down to the RA waveform. Repeat this with the next ECG complex (see Fig ). 5. Align the PR interval with the Compares electrical activity with mechanical activity. Usually three waves are present on the RA waveform. The a wave correlates with this interval. RA waveform. 6. Identify the a wave. The a wave is seen approximately ms after the P wave. The c wave follows the a wave, and the v wave follows the c wave. 7. Identify the scale setting of the RA waveform on the monitor (Fig ). 8. Measure the mean of the a wave to obtain the RAP (see Fig ). Optimizes the view of the waveform and aids in measurement of the pressure. The a wave represents atrial contraction and reflects right ventricular filling at end diastole. At times, the c wave is not present. The a wave reflects atrial contraction. The c wave reflects closure of the tricuspid valve. The v wave reflects passive filling of the atria. The RAP scale commonly is set at 20 mm Hg and may be adjusted to the patient s RAP to optimize the view of the waveform. Scale settings may vary based on monitoring equipment. Figure 72-8 Obtaining measurements of right-atrial and central venous pressures (RA/CVP). Aligning the a wave on the RA/CVP waveform with the PR interval on the electrocardiogram facilitates accurate measurement of RA/CVP at end diastole. (From Ahrens TS, Taylor LK: Hemodynamic waveform analysis, Philadelphia, 1992, Saunders.)

11 72 Pulmonary Artery Catheter Insertion (Assist) and Pressure Monitoring 619 PA Systolic and Diastolic Pressures 1. Position the patient in the supine position with the head of the bed from 0 to 45 degrees. (Level B * ) 2. Print a dual-channel strip of the ECG and PA waveform (Fig ). Studies have determined that the RA and PA pressures are accurate in this position. 3,6,7,10,18,20,22,34,35 PA pressures are measured from the graphic strip when respiratory variation of the waveform is noted because the effect of ventilation can be identified. RA and PA pressures may be accurate for patients in the supine position with the head of the bed elevated up to 60 degrees, 7,22 but additional studies are needed to support this. Only one study 19 supports the accuracy of hemodynamic values for patients in the lateral positions; other studies 3,13,18,26,33 do not. The majority of the studies 1,2,12,17,21,27,32 support the accuracy of hemodynamic monitoring for patients in the prone position, yet two studies showed that prone positioning caused an increase in hemodynamic values. 28,31 Some monitors have the capability of freeze framing waveforms. A cursor can be used to measure pressures. *Level B: Well-designed, controlled studies with results that consistently support a specifi c action, intervention, or treatment. Procedure continues on following page Figure 72-9 Obtaining measurements of pressure in the pulmonary artery (PA). For systolic pressure, align the peak of the systolic waveform with the QT interval on the electrocardiogram. For PA diastolic pressure, use the end of the QRS as a marker to detect the PA diastolic phase. Obtain the reading just before the upstroke of the systolic waveform. (From Ahrens TS, Taylor LK: Hemodynamic waveform analysis, Philadelphia, 1992, Saunders.)

12 620 Unit II Cardiovascular System 3. Measure the PA pressure at end expiration. 4. Identify the QT interval on the ECG strip. 5. Align the QT interval with the PA waveform. 6. Identify the scale setting of the PA waveform on the monitor. 7. Measure the PA systolic pressure at the peak of the systolic waveform on the PA waveform (see Fig ). 8. Align the end of the QRS complex with the PA waveform (see Fig ). 9. Measure the PA diastolic pressure at the point of the intersection of this line (see Fig ). PAOP 1. Position the patient in the supine position with the head of the bed from 0 to 45 degrees. (Level B *) 2. Fill the PA balloon syringe with 1.5 ml of air. 3. Connect the PA balloon syringe to the gate valve or stopcock of the balloon port of the PA catheter (see Fig ). The effects of intrathoracic pressure on the PAP is minimized at the end-expiration phase of the respiratory cycle. Represents ventricular depolarization. Allows comparison of cardiac electrical activity with mechanical activity. Optimizes the view of the waveform and aids in measurement of the pressure. Reflects the highest PA systolic pressure. Compares electrical activity with mechanical activity. The end of the QRS complex correlates with ventricular enddiastolic pressure. This point occurs just before the upstroke of the systolic pressure. Studies have determined that the RA and PA pressures are accurate in this position. 3,6,7,10,18,20,22,34,35 More than 1.5 ml of air may rupture the PA balloon and the pulmonary arteriole. This port is designed for balloon air inflation. The PAP scale commonly is set at 40 mm Hg and may be adjusted to the patient s PAP to optimize the view of the waveform. Scale settings may vary based on monitoring equipment. RA and PA pressures may be accurate for patients in the supine position with the head of the bed elevated up to 60 degrees, 7,22 but additional studies are needed to support this. Only one study 19 supports the accuracy of hemodynamic values for patients in the lateral positions; other studies 3,13,18,26,33 do not. The majority of the studies 1,2,12,17,21,27,32 support the accuracy of hemodynamic monitoring for patients in the prone position, but two studies demonstrated that prone positioning caused an increase in hemodynamic values. 28,31 *Level B: Well-designed, controlled studies with results that consistently support a specifi c action, intervention, or treatment.

13 72 Pulmonary Artery Catheter Insertion (Assist) and Pressure Monitoring Print a dual-channel strip of the ECG and PA waveform. 5. Slowly inflate the balloon with air until the PA waveform changes to a PAO waveform (Fig ). 6. Inflate the balloon for no more than 8 15 seconds (2 4 respiratory cycles). 7. Disconnect the syringe from the balloon-inflation port to passively deflate the balloon. (Level M * ) 8. Observe the monitor to verify the PAO waveform changes back to the PA waveform. 9. Expel air from the balloon syringe. The PAO pressures are measured from the graphic strip because the effect of ventilation can be identified. A slight resistance is usually felt during inflation of the balloon. Only enough air needed to convert the PA waveform to a PAO waveform should be instilled. Thus the entire amount of 1.5 ml of air is not necessarily needed. Prolonged inflation of the balloon can cause pulmonary arteriole infarction and/or rupture, with potentially life-threatening hemorrhage. 14 Allows air to passively escape from the balloon. Ensures adequate balloon deflation and safe positioning of the PA catheter for continuous monitoring. The syringe should remain empty when reconnected so that accidental balloon inflation does not occur. Some monitors have the capability of freeze framing waveforms. A cursor can be used to measure pressures. Avoid overinflation of the balloon because it can cause pulmonary arteriole infarction or rupture, resulting in potentially lifethreatening hemorrhage. 14 Active withdrawal of air from the balloon can weaken the balloon, pull the balloon structure into the inflation lumen, and possibly cause balloon rupture. *Level M: Manufacturer s recommendations only. Procedure continues on following page Figure Change in pulmonary artery pressure (PAP) waveform to pulmonary artery occlusion pressure waveform with balloon inflation. The balloon is inflated while the bedside monitor is observed for change in the waveform. Balloon inflation (arrow) in patient with normal pulmonary artery occlusion pressure. Pulmonary artery occlusion pressure (PAOP) is also referred to as pulmonary artery wedge pressure (PAWP).

14 622 Unit II Cardiovascular System 10. Reconnect the empty balloon syringe to the balloon-inflation port. 11. Follow institutional standard regarding keeping the gate valve or the stopcock open. 12. With the dual-channel recorded strip, draw a vertical line from the beginning of the P wave of one of the ECG complexes down to the PAO waveform. Repeat this with the next ECG complex. 13. Align the end of a QRS complex of the ECG strip with the PAO waveform (Fig ). The syringe that is manufactured for the PA catheter should be connected to the PA balloon port to avoid loss of the custom designed syringe. This syringe can be filled with only 1.5 ml of air, thus serving as a safety feature to minimize the chance of balloon overinflation. The most important considerations are that the balloon syringe is attached to the balloon-inflation port, the syringe is empty, and the PA distal waveform reflects a pulmonary artery waveform. Compares cardiac electrical activity with mechanical activity. Two waves ( a and v ) to three waves ( a, c, and v waves) will be present on the PAO waveform. Aligns relationship of cardiac electrical activity with mechanical activity The c waves commonly are not present on PAO waveforms because of the distance the pressure needs to travel back to the transducer. Figure Obtaining measurement of the pulmonary artery occlusion pressure (PAOP). For accurate readings, align the a wave from the PAO waveform with the end of the QRS on the electrocardiogram at end diastole. Pulmonary artery occlusion pressure (PAOP) is also referred to as pulmonary artery wedge pressure (PAWP). (From Ahrens TS, Taylor LK: Hemodynamic waveform analysis, Philadelphia, 1992, Saunders.)

15 72 Pulmonary Artery Catheter Insertion (Assist) and Pressure Monitoring Identify the a wave (see Fig ). 15. Identify the scale of the PAO tracing. 16. Measure the mean of the a wave to obtain the PAOP (see Fig ). 17. Compare the PADP with the PAOP. 18. Follow PADP if a close correlation is found between PADP and PAOP. 19. Follow the PAOP if > 4 mm Hg of difference is found between PAOP and PADP. The a wave correlates with the end of the QRS complex. The c wave follows the a wave, and the v wave follows the c wave. Aids in determination of pressure measurement. The a wave represents atrial contraction and reflects LV filling at end diastole. The PAOP is commonly 1 4 mm Hg less than the PADP. PADPs that correlate with PAOPs represent LV filling pressures. Considered an accurate measurement of LV filling pressures. Ensures the accuracy of measurements. Measurement of Hemodynamic Pressures at End Expiration 1. Measure all hemodynamic pressures at end expiration to ensure accuracy. 2. Determine end expiration by observing the rise and fall of the chest during breathing and use of printed graphics of hemodynamic, respiratory, capnography, or continuous airway pressure waveforms. Atmospheric and alveolar pressures are approximately equal at end expiration. Intrathoracic pressure is closest to zero at end expiration. Measurement of hemodynamic pressures is most accurate at end expiration because pulmonary pressures have minimal effect on intracardiac pressures. Aids in the determination of the end expiratory phase of ventilation. Determining End Expiration for the Patient Breathing Spontaneously 1. Record a strip of the PA waveform. 2. Note that the pressure waveform dips down during the inspiratory phase of spontaneous breathing (Fig ). 3. Note that the pressure waveform elevates during the expiratory phase of breathing (see Fig ). A labeled recording aids in determination of accurate hemodynamic pressure values. Intrapleural pressure decreases during spontaneous inspiration, and this decrease is reflected by a fall in cardiac pressures. At end-expiration atmospheric and intrathoracic pressures (pleural and alveolar) are equalized; thus cardiac pressures are most accurately reflected. If only two waves are present, the first wave is the a wave and the second wave is the v wave. The PA scale commonly is set at 40 mm Hg. If PEEP is being used and the PEEP is more than 10 cm H 2 O, adjustments in determination of the pressures may be necessary. Follow institutional standards. Significant differences between PADP and PAOP may exist for patients with pulmonary hypertension, chronic obstructive lung disease, acute respiratory distress syndrome, pulmonary embolus, and tachycardia. Minimizes the number of times the PA balloon is inflated. In patients who are breathing spontaneously, the normal inspiratory : expiratory ratio is approximately 1 : 2. Procedure continues on following page

16 624 Unit II Cardiovascular System Figure Respiratory fluctuations of pulmonary artery pressure (PAP) waveform in a spontaneously breathing patient. The location of inspiration (I) is marked on the waveform. The points just before inspiration are end expiration, where readings are taken. 4. Measure the pressure at the end of the expiratory phase (see Fig ). Ensures accurate and consistent pressure measurements. Determining End Expiration for the Patient Receiving Positive Pressure Mechanical Ventilation 1. Record a strip of the PA A labeled recording aids in waveform. determination of accurate 2. Note that the pressure waveform elevates as a breath is delivered by the ventilator (Fig ). hemodynamic pressure values. As the ventilator delivers a positive pressure breath to the lungs, an increase in intrathoracic pressure results. This increase in intrathoracic pressure causes an increase in cardiac pressures. 3. Note that the pressure waveform As the mechanical breath is exhaled, dips down as the breath is intrathoracic pressures decrease and exhaled (see Fig ). cardiac pressures are most accurately and consistently measured. Determining End Expiration for the Patient Receiving Intermittent Mandatory Mechanical Ventilation 1. Record a strip of the PA waveform. 2. If the patient is receiving intermittent mandatory ventilation, measure the pressure during the end expiration. 3. Note that the pressure waveform elevates as a breath is delivered by the ventilator (Fig ). A labeled recording aids in determination of accurate hemodynamic pressure monitoring. Aids in accuracy of pressure measurements. As the ventilator delivers a breath to the lungs, an increase in intrathoracic pressure results. This increase in pressure causes an increase in cardiac pressures. Procedure continues on following page

17 72 Pulmonary Artery Catheter Insertion (Assist) and Pressure Monitoring Figure Patient on mechanical ventilation (on pressure support type ventilator) who had no spontaneous respiration because of neuromuscular-blocking agent (vecuronium). The point of end expiration is located just before the ventilator artifact. Pulmonary artery occlusion pressure (PAOP) is also referred to as pulmonary artery wedge pressure (PAWP). Figure Intermittent mandatory ventilation mode of ventilation and the effect on the pulmonary artery waveform. (From Ahrens TS, Taylor LK: Hemodynamic waveform analysis, Philadelphia, 1992, Saunders.) 625

18 626 Unit II Cardiovascular System 4. Note that the pressure waveform dips down as the breath is exhaled (see Fig ). As the mechanical breath is exhaled, intrathoracic pressure decreases and cardiac pressures are more accurately reflected. 5. Identify the patient s spontaneous breath (see Fig ). This breath may occur just before triggered ventilator breaths. 6. Determine end expiration. Ensures accuracy of measurements. Airway pressure waveforms can be used to facilitate identification of end expiration. Expected Outcomes Accurate placement of the PA catheter Adequate and appropriate waveforms Ability to obtain accurate cardiac pressure measurements and associated hemodynamic data Evaluation of information obtained to guide diagnostic and therapeutic interventions Unexpected Outcomes Pneumothorax or hemothorax Infection/sepsis Ventricular dysrhythmias Heart block Misplacement Hemorrhage Hematoma Pericardial or ventricular rupture Venous air embolism Cardiac tamponade PA infarction PA rupture PA catheter balloon rupture PA catheter knotting Pseudoaneurysm formation Heparin-induced thrombocytopenia Thrombosis Valvular damage Pain Patient Monitoring and Care Steps Rationale Reportable Conditions 1. Recheck transducer leveling whenever patient position changes. 2. Zero the transducer during initial setup or before insertion if disconnection occurs between the transducer and the monitoring cable, if disconnection occurs between the monitoring cable and the monitor, and when the values obtained do not fit the clinical picture. Ensures accurate reference point for the left atrium. Ensures accuracy of the hemodynamic monitoring system. These conditions should be reported if they persist despite nursing interventions.

19 72 Pulmonary Artery Catheter Insertion (Assist) and Pressure Monitoring 627 Patient Monitoring and Care Steps Rationale Reportable Conditions 3. Place sterile injectable or noninjectable caps on all stopcocks. Replace with new sterile caps whenever the caps are removed. 4. Monitor the pressure-transducer system (pressure tubing, transducer, stopcocks, etc.) for air and eliminate air from the system. 5. Continuously monitor hemodynamic waveforms and obtain hemodynamic values (pulmonary artery systolic pressure, PADP, RAP) hourly and as necessary with condition changes and to evaluate therapy interventions. Follow institutional standards for obtaining hemodynamic values. 6. Obtain CO, cardiac index, and systemic vascular resistance and additional parameters after catheter insertion and as necessary per patient condition and interventions. 7. Change the hemodynamic monitoring system (flush solution, pressure tubing, transducers, and stopcocks) every 96 hours. (Level B *) The flush solution may need to be changed more frequently if near empty of solution. 8. Perform a dynamic response test (square wave test) at the start of each shift, with a change of the waveform, or after the system is opened to air (see Fig ). 9. Label the tubing with the date and time the system was prepared. 10. Maintain the pressure bag or device at 300 mm Hg. Continued Stopcocks can be a source of contamination. Stopcocks that are part of the initial setup are packaged with vented caps. Vented caps need to be replaced with sterile injectable or noninjectable caps to maintain a closed system and reduce the risk of contamination and infection. Air in the transducer system affects the accuracy of pressure measurements. Air emboli are also potentially fatal. Provides for continuous waveform analysis and assessment of patient status. Monitors patient status and response to therapeutic interventions. The Centers for Disease Control and Prevention (CDC), 23 the Infusion Nurses Society, 16 and research findings 23,25 recommend that the hemodynamic flush system can be used safely for 96 hours. This recommendation is based on research conducted with disposable pressure-monitoring systems used for peripheral and central lines. An optimally damped system provides an accurate waveform. Identifies when the system needs to be changed. At 300 mm Hg, each flush device delivers approximately 1 3 ml/hr to maintain patency of the system. Suspected air emboli Abnormal hemodynamic waveforms or pressures Abnormal hemodynamic parameters or significant changes in hemodynamic parameters Overdamped or underdamped waveforms that cannot be corrected with troubleshooting procedures * Level B: Well-designed, controlled studies with results that consistently support a specifi c action, intervention, or treatment. Procedure continues on following page

20 628 Unit II Cardiovascular System Patient Monitoring and Care Steps Rationale Reportable Conditions 11. Do not fast flush the distal lumen of the PA catheter for longer than 2 seconds Never flush the distal lumen of the PA catheter when the balloon is wedged in the pulmonary artery. 13. Use aseptic technique when withdrawing from or flushing the PA catheter. 14. Clear the system, including stopcocks, of all traces of blood after blood withdrawal. 15. Maintain sterility and integrity of the plastic sleeve covering the PA catheter. 16. Blood products and albumin should never be infused through the PA catheter. 17. IV fluids are never infused via the distal lumen of the PA catheter and are sometimes infused via the proximal lumen of the PA catheter when IV access is necessary. 18. Replace gauze dressings every 2 days and transparent dressings at least every 5 7 days and more frequently as needed. 15,16,24,30 (Level D *) 19. Perform central venous catheter site care (see Procedure 66 ). 20. Print PA waveform strips to place on the patient s chart at the start of each shift and whenever a change in the waveform occurs. Continued PA rupture may occur with prolonged flushing of high-pressure fluid. Excessive PA pressure may cause PA damage or rupture. Prevents contamination of the system and related infection. Blood can become a medium for bacterial growth. 24 Clots also may be flushed into the catheter if all blood is not eliminated. Any tear in the sleeve breaks the sterile barrier, making catheter repositioning no longer possible. Viscous blood may occlude the catheter. The accuracy of the PA monitoring system may be adversely affected. PA monitoring is not possible, and a life-threatening situation can occur (e.g., undetected wedged PA catheter). Decreases the risk for infection at the catheter site. The Centers for Disease Control and Prevention (CDC) and the Infusion Nurses Society recommend replacing the dressing when it becomes damp, loosened, or soiled or when inspection of the site is necessary. 15,16,24 Ensures consistency of dressing change and indicates when the next change will occur. The printed waveform allows assessment of the adequacy of the waveform, the presence of damping, and if respiratory variation is present. Hemoptysis Hemoptysis Defects in the integrity of the plastic sleeve Signs or symptoms of infection * Level D: Peer-reviewed professional and organizational standards with the support of clinical study recommendations.

21 72 Pulmonary Artery Catheter Insertion (Assist) and Pressure Monitoring 629 Patient Monitoring and Care Continued Steps Rationale Reportable Conditions 21. Assess the need for the PA catheter daily. If long-term use of the PA catheter is needed, consider changing the PA catheter every 7 days. (Level B * ) 22. Follow institutional standards for assessing pain. Administer analgesia as prescribed. The Centers for Disease Control and Prevention (CDC) 24 and research findings 4,11 recommend that PA catheters do not need to be changed more frequently than every 7 days. There are no specific recommendations regarding routine replacement of PA catheters that need to be in place for >7 days. 11,24 Guidewire exchanges should not be used routinely. A guidewire exchange should only be used to replace a catheter that is malfunctioning. 24 Signs and symptoms of infection at the PA catheter insertion site Signs and symptoms of sepsis Identifies need for pain interventions. Continued pain despite pain interventions *Level B: Well-designed, controlled studies with results that consistently support a specifi c action, intervention, or treatment. Documentation Documentation should include the following: Patient and family education Completion of informed consent Universal protocol requirements Insertion of the PA catheter External centimeter marking of PA catheter noted at exit site Patient tolerance of procedure Confirmation of PA catheter placement (e.g., waveforms, chest radiograph) Date and time of PA catheter site care and dressing change Pain assessment, interventions, and effectiveness Cardiac rhythm during PA catheter insertion and monitoring Site assessment PA pressures (RA/CVP, RV, PA systolic, diastolic, mean, and PAOP) Waveforms (RA/CVP, RV, pulmonary artery pressure, PAOP) CO/CI and systemic vascular resistance Occurrence of unexpected outcomes and interventions References and Additional Readings For a complete list of references and additional readings for this procedure, scan this QR code with any freely available smartphone code reader app, or visit