Pulmonary Artery Catheter Insertion (Assist) and Pressure Monitoring

Transcription

1 P ROCEDURE 72 Pulmonary Artery Catheter Insertion (Assist) and Pressure Monitoring P U R P O S E : Pulmonary artery (PA) catheters are used to determine hemodynamic status in critically ill patients. PA catheters provide information about right- and left-sided intracardiac pressures and cardiac output (CO). Additional functions available are fiberoptic 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 guide therapeutic intervention, including administration of fluids and diuretics and titration of vasoactive and inotropic medications. Teresa Preuss Debra Lynn-McHale Wiegand PREREQUISITE NURSING KNOWLEDGE Knowledge of the normal cardiovascular anatomy and physiology Knowledge of the normal pulmonary anatomy and physiology Knowledge of principles of aseptic technique Basic dysrhythmia recognition and treatment of lifethreatening dysrhythmias Advanced cardiac life support knowledge and skills Anatomy of the PA catheter (Fig. 72-1) and the location of the PA catheter in the heart and pulmonary artery (Fig. 72-2) The setup of the hemodynamic monitoring system (see Procedure 75). Understanding of normal hemodynamic values (see Table 63-1). The pulmonary artery catheter contains a proximal injectate lumen port, a PA distal lumen port, a thermistor connector, and a balloon-inflation valve. Some catheters also have two infusion ports, an RA and an RV lumen 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 pulmonary artery. This lumen also allows for sampling of mixed venous blood. The proximal injectate lumen is used to monitor the right atrial pressure and inject the solution used to obtain CO. The balloon-inflation valve is used to obtain the pulmonary artery waveform pressure (PAWP). Pulmonary artery wedge pressure may be referred to as pulmonary artery occlusion pressure. The PA diastolic pressure and the PAWP are indirect measures of left ventricular end-diastolic pressure (LVEDP). Usually, the PAWP 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. This minimizes the frequency of balloon inflation and thus decreases the potential of balloon rupture. Differences between the PADP and the PAWP may exist for patients with pulmonary hypertension, chronic obstructive lung disease, acute respiratory distress syndrome (ARDS), pulmonary embolus, and tachycardia. Indications for PA catheter therapy (see Procedure 71 for additional indications) are as follows: Aid in the diagnosis of complications after acute myocardial infarction (MI) that may include heart failure, cardiogenic shock, papillary muscle rupture, mitral regurgitation, ventricular septal rupture, or cardiac rupture with tamponade 549

2 550 Unit II Cardiovascular System Figure 72-1 Anatomy of the pulmonary artery (PA) catheter. The standard No. 7.5-Fr thermodilution PA catheter is 110 cm in length and contains four lumens. It is constructed of radiopaque polyvinyl chloride. In 10-cm increments, there are black markings on the catheter 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 wedge pressure. The narrow black bands represent 10-cm lengths and the wide black bands indicate 50-cm lengths. (From Visalli, F., and Evans, P. [1981]. The Swan-Ganz catheter: a program for teaching safe effective use. Nursing, 81[11], 1.) Figure 72-2 Pulmonary artery (PA) catheter location within the heart. Pulmonary artery wedge pressure (PAWP) is an indirect measure of left arterial and left ventricular end-diastolic pressure. (From Kersten, L.D. [1989]. Comprehensive Respiratory Nursing. Philadelphia: W.B. Saunders.)

3 72 Pulmonary Artery Catheter Insertion (Assist) and Pressure Monitoring 551 Assessment of ventricular function in heart failure Management of high-risk cardiac patients undergoing surgical procedures during preoperative, intraoperative, or postoperative periods Differentiation of hypotensive states, such as hypovolemia, sepsis, heart failure, and cardiac tamponade Hemodynamic monitoring and evaluation of patients with major organ dysfunction who require fluid management and infusion of vasoactive medications, such as patients with burns, trauma, acute respiratory distress syndrome (ARDS), or gastrointestinal bleeding There are no absolute contraindications to hemodynamic monitoring with a PA catheter, but an assessment of risk versus benefit to the patient should be considered. Relative contraindications to pulmonary artery catheter insertion include presence of fever, presence of a mechanical tricuspid valve, and coagulopathic state. A patient with left bundle branch block may develop a right bundle branch block during PA catheter insertion resulting in complete heart block. In these patients a temporary pacing mode should be readily available. Pulmonary artery pressures may be elevated as a result of pulmonary artery hypertension, pulmonary disease, mitral valve disease, left ventricular failure, atrial or ventricular left-to-right shunt, pulmonary emboli, or hypervolemia. Pulmonary artery pressures may be decreased due to hypovolemia or vasodilation. Waveforms that occur during insertion, including right atrial (RA), right ventricular (RV), PA, and pulmonary artery wedge (PAW) (Fig. 72-3). 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). The a wave reflects right 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/CVP) and in PAWP 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 stenosis, right ventricular ischemia or infarction, right ventricular failure, pulmonary artery hypertension, and atrioventricular (AV) dissociation. Elevated a waves in the PAWP waveform may occur in patients with mitral stenosis, acute left ventricular ischemia or infarction, left ventricular failure, and AV dissociation. Elevated v waves in the RAP/CVP waveform may occur in patients with tricuspid insufficiency. Elevated v waves in the PAWP waveform may occur in patients with mitral insufficiency or a ruptured papillary muscle. Insertion and placement verification should occur as follows: The PA catheter may be inserted through the subclavian, internal jugular, femoral, external jugular, or antecubital veins. Placement of a central venous catheter in a subclavian site instead of a jugular or femoral site reduces the risk for infection. 20 The standard 7.5-F PA catheter is 110 cm long and has black markings at 10-cm increments and wide black markings at 50-cm increments to facilitate insertion and positioning (see Fig. 72-1). The catheter should reach the PA after being advanced 45 to 55 cm from the internal jugular vein or 70 to 80 cm from a femoral or an antecubital vein. Verification of PA catheter placement is validated by waveform analysis. Correct catheter placement demonstrates a PAW tracing when the balloon is inflated and a PA tracing when the balloon is deflated. Catheter placement is also verified by chest x-ray. The PA catheter contains latex which may cause allergic reactions. Figure 72-3 Schematic of waveform progression as a pulmonary artery catheter is inserted through the various cardiac chambers. (From Abbott Critical Care Systems, Mountain View, CA.)

4 W _ /24/05 4:37 PM Unit II Page 552 Cardiovascular System Figure 72-4 Identification of a, c, and v waves in the waveform for right atrial and central venous pressure (RA/CVP). Atrial waveforms are characterized by three components: a, c, and v waves. The a wave reflects atrial cotraction, the c wave reflects closure of the tricuspid valve, and the v wave reflects passive filling of the atria. (From Ahrens, T.S., and Taylor, L.K. [1992]. Hemodynamic Waveform Analysis. Philadelphia: W.B. Saunders.) Figure 72-5 Normal pulmonary artery wedge pressure (PAWP) waveform and components. Note the delay in the a, c, and v waves because of the time it takes 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. EQUIPMENT PA catheter (non-heparin-coated 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 Pressure transducer system, including flush solution recommended according to institution standard, a pressure bag or device, pressure tubing with flush device, and transducers Dual-channel recorder Sterile normal saline intravenous fluid for flushing the introducer and catheter infusion ports

5 72 Pulmonary Artery Catheter Insertion (Assist) and Pressure Monitoring 553 Antiseptic solution (e.g., 2% chlorhexidine-based preparation) Caps, fluid-shield masks, sterile gowns, sterile gloves, nonsterile gloves and sterile drapes 1% lidocaine without epinephrine Sterile basin or cup Sterile water or normal saline Sterile dressing supplies Stopcocks (may be included in some pressure tubing systems) Nonvented caps for stopcocks Additional equipment as needed includes the following: Fluoroscope Emergency equipment Temporary pacing equipment Indelible marker Transducer holder PATIENT AND FAMILY EDUCATION Provide the patient and family with information about the PA catheter, reason for the PA catheter, and explanation of the equipment. Rationale: Assists the patient and family to understand the procedure, why it is needed, and how it will help the patient. Decreases patient and family anxiety. Explain the patient s expected participation during the procedure. Rationale: Encourages patient assistance. PATIENT ASSESSMENT AND PREPARATION Patient Assessment Determine baseline hemodynamic, cardiovascular, peripheral vascular, and neurovascular status. Rationale: 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 end-expiratory pressure (PEEP) or continuous positive airway pressure (CPAP). Rationale: The presence of mechanical ventilation alters hemodynamic waveforms and pressures. Assess the patient s past medical history specifically related to problems with venous access sites, cardiac anatomy, and pulmonary anatomy. Rationale: Identification of obstructions or disease should be made prior to the insertion attempt. Assess the patient s current laboratory profile, including electrolyte, coagulation and arterial blood gas studies. Rationale: Identifies laboratory abnormalities. Baseline coagulation studies are helpful in determining the risk for bleeding. Electrolyte and arterial blood gas imbalances may increase cardiac irritability. Patient Preparation Ensure that the patient and family understand preprocedural teaching. Answer questions as they arise and reinforce information as needed. Rationale: Evaluates and reinforces understanding of previously taught information. Ensure that informed consent has been obtained. Rationale: Protects the rights of the patient and makes a competent decision possible for the patient. Validate the patency of the peripheral IV line. Rationale: Access may be needed for administration of emergency medications or fluids. Assist the patient to the supine position. Rationale: Prepares the patient for skin preparation, catheter insertion, and setup of the sterile field. Sedate the patient or provide prescribed analgesics as needed. Rationale: Movement of the patient may inhibit insertion of the PA catheter. Procedure Pressure Monitoring Assisting With PA Catheter Insertion 1. Wash hands. Reduces the possible transmission of microorganisms and body secretions; standard precautions. 2. Follow institutional standard for Heparinized flush solutions are Although heparin may prevent adding heparin to flush solution commonly used to minimize thrombi thrombosis, 20 it has been (see Procedure 75). and fibrin deposits on catheters that associated with thrombocymight lead to thrombosis or bacterial colonization of the catheter. topenia and other hematologic complications. 4 Further research is needed regarding use of heparin versus normal saline to maintain PA line patency. Procedure continues on the following page

6 554 Unit II Cardiovascular System Procedure 3. Prime or flush the entire pressure Removes air bubbles. Air bubbles Air is more easily removed transducer system (see Procedure 75). introduced into the patient s from the hemodynamic circulation can cause air embolism. tubing when the system is Air bubbles within the tubing will not under pressure. dampen the waveform. 4. Apply and maintain pressure in the Each flush device delivers 1 to pressure bag or device at 300 mm Hg. 3 ml/hr to maintain patency of the hemodynamic system. 5. Wash hands and don caps, fluid shield Reduces the transmission of masks, sterile gowns, and gloves for microorganisms and body all health care personnel involved secretions; standard precautions. in procedure. 6. Assist the physician or advanced Aids in maintaining sterility. practice nurse with opening the PA catheter and introducer kits. 7. When the sheath introducer is in place, Maintains the patency of the sheath connect a normal saline IV solution introducer infusion port. to the infusion port. 8. Connect the pressure transducer/flush Removes air from the pulmonary Flush additional infusion ports system to the PA distal and proximal ports artery catheter. prior to insertion. of the PA catheter and flush all lumens. 9. Connect the pressure cables from the Connects the pulmonary artery PA distal and proximal injectate catheter to the bedside monitoring transducers to the bedside monitor system. (see Fig. 75-2). 10. Connect the thermistor connector Allows the core temperature to be of the PA catheter to the CO monitor monitored and is needed for or module (see Fig. 75-3). CO measurement. 11. If inserting a PA catheter with the Calibrates the system. Follow manufacturer guidelines ability to monitor mixed venous for catheter calibration. oxygenation, the fiberoptics are calibrated prior to removal from the package (see Procedure 14). 12. Set the scales for each pressure tracing. Permits waveform analysis. 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. Scales are adjusted based on patient pressures. 13. Examine the PA catheter for defects Faulty catheters are replaced. The inflated balloon can be in construction and check balloon placed in a container of integrity. sterile normal saline or water. No air bubbles should be seen. If air bubbles are seen, there is a defect in the balloon integrity. 14. Level the RA (proximal injectate) The phlebostatic axis approximates The reference point for the air-fluid interface (zeroing stopcock) the level of the atria and is the atria changes when a patient and the PA (distal) air-fluid interface reference point for patients in is in the lateral position (zeroing stopcock) to the the supine position (see Fig. 75-7). (see Fig. 75-8). phlebostatic axis.

7 Procedure 72 Pulmonary Artery Catheter Insertion (Assist) and Pressure Monitoring Zero the system connected to the Prepares the monitoring system so that PA lumen and RA lumen of the PA pressures can be obtained during PA catheter by turning the stopcock catheter insertion. off to the patient, opening it to air, and zeroing the monitoring system (see Procedure 75). 16. The physician or advanced practice A sterile sleeve prevents contamination Research has not yet nurse places a sterile plastic sleeve over of the PA catheter, allows repositioning determined how long the the PA catheter, attaching it to the PA of the catheter after the initial insertion, sleeve remains sterile. catheter before the catheter is inserted. 20 and reduces blood stream infections As insertion begins, continuously Provides documentation of RA, RV, A dual-channel recorder is run an ECG and PA distal and PA pressures during insertion preferred, because then the waveform strip. and dysrhythmia occurrence during ECG and the PA waveform insertion. can be simultaneously recorded. 18. After the tip of the PA catheter is The presence of the tip of the catheter The inflated balloon advances in the right atrium, inflate the balloon in the right atrium is validated by the PA catheter through the with no more than 1.25 to 1.5 ml of waveform analysis (see Fig. 72-3). right side of the heart and air and close the gate valve or the Closing the gate valve or the stopcock into the PA, minimizing the stopcock (Fig. 72-6). holds air in the balloon during chance of endocardial insertion. damage. 19. Observe for RA, RV, PA, and then Placement in the PA is validated Monitor the ECG tracing as PAW waveforms (see Fig. 72-3). by waveform analysis. the PA catheter is inserted, because ventricular dysrhythmias may occur due to right ventricular irritability. Right ventricular pressures are obtained only during insertion. 20. Verify that the catheter is in the proper When the balloon is inflated, the The catheter usually reaches the position. When the balloon is deflated, catheter floats from the pulmonary PA after being advanced the monitor shows a PA tracing; when artery to a smaller arteriole 45 to 55 cm from the internal the balloon is inflated, the monitor will (see Fig. 72-3). jugular or subclavian vein or show a PAW tracing. 70 to 80 cm from a femoral or antecubital vein. Placement may vary depending on patient size. A chest x-ray is obtained to verify catheter position. Procedure continues on the following page Sliding gate valve Catheter Arrow aligned indicates open position CLOSED Arrow offset indicates closed position OPEN Figure 72-6 Gate valve in the open position on the pulmonary artery (PA) (distal) lumen of the PA catheter. (From Baxter Edwards Corporation.) Gate Valve Operation

8 556 Unit II Cardiovascular System Procedure 21. After the pulmonary artery catheter The gate valve or stopcock is closed Air is expelled from the is in place, open the balloon inflation during insertion to retain air in the PA syringe, and the empty gate valve or stopcock and remove balloon. The air is then released syringe is reconnected to the the PA syringe. so that continuous monitoring end of the balloon inflation of the PA waveform can be valve. performed. 22. Reassess accurate leveling and secure Ensures that the air-filled interface Leveling ensures accuracy. The the system to the patient s chest or arm (zeroing stopcock) is maintained point of the phlebostatic axis or to a pole mount. at the level of the phlebostatic axis. should be marked with an If the air-fluid interface is above indelible marker, especially the phlebostatic axis, PA pressures if using a pole-mount setup. will be falsely low. If the air-fluid interface is below the phlebostatic axis, PA pressures will be falsely high. 23. Zero both the RA and PA hemodynamic Ensures accuracy of the system with monitoring systems (see Procedure 75). the established reference point. 24. Observe the waveform and perform a Results indicate whether the system dynamic response test (square wave test) is correctly damped. (see Fig. 59-3). 25. Place a sterile, occlusive dressing Reduces the risk for infection. on the insertion site. 26. Document the external cm marking Identifies the length of the PA If the cm marking is not visible at of the PA catheter at the introducer catheter inserted and allows for the exit site, measure the distance exit site. evaluation of PA catheter from the introducer exit site to movement. the nearest visible marking. 27. Set the alarms. Upper and lower alarm Activates the bedside and central limits are set on the basis of the alarm system. patient s current clinical status and hemodynamic values. 28. Discard used supplies and wash hands. Reduces the transmission of microorganisms; standard precautions. 29. Obtain the chest x-ray. Verifies catheter placement. Obtaining PA Pressure Measurements RA/CVP 1. Position the patient in the supine Studies have determined that the RA and PA pressures may be position with the head of the bed RA and PA pressures are accurate accurate for patients in the from 0 to 45 degrees. (Level VI: Clinical in this position. 3,5,6,9,14,16,18,28,29 supine position with the head studies in a variety of patient of the bed elevated up to populations and situations to support recommendations.) 60 degrees, 6,18 but additional studies are needed to support this. Only one study 15 supports the accuracy of hemodynamic values for patients in the lateral positions; other studies do not. 3,11,14,22,27 The majority of studies support the accuracy of hemodynamic monitoring for patients in the prone position. 1,2,10,13,17,23,26 Two studies demonstrated that prone positioning caused an increase in hemodynamic values. 24,25

9 Procedure 72 Pulmonary Artery Catheter Insertion (Assist) and Pressure Monitoring Run a dual-channel strip of the ECG RA pressures should be determined Digital data can be used to and RA waveform (Fig. 72-7). from the graphic strip, because determine RA pressure if the effect of ventilation can be ventilation does not affect the identified. RA pressure waveform. Some monitors have the capability of freeze framing waveforms. A cursor can be used to determine pressure measurements. 3. Measure RA pressure at end-expiration. Measurement is most accurate as the effects of pulmonary pressures are minimized. 4. Using the dual-channel recorded strip, Compares electrical activity to At times, the c wave is not draw a vertical line from the beginning mechanical activity. Usually present. of the P wave of one of the ECG three waves are present on complexes down to the RA waveform. the RA waveform. Repeat this with the next ECG complex (see Fig. 72-7). 5. Align the PR interval with the RA The a wave correlates with this waveform. interval. 6. Identify the a wave. The a wave is seen approximately The a wave reflects atrial 80 to 100 milliseconds after the contraction. The c wave reflects P wave. The c wave follows closure of the tricuspid valve. the a wave, and the v wave follows The v wave reflects passive the c wave. filling of the atria (see Fig. 72-4). 7. Identify the scale of the RA tracing Aids in determining the pressure RA scale commonly is set at (Fig. 72-8). measurement. 20 mm Hg. 8. Measure the mean of the a wave to obtain The a wave represents atrial the RA pressure (RAP) (see Fig. 72-8). contraction and reflects right ventricular filling at end-diastole. PA Systolic and Diastolic Pressures 1. Position the patient in the supine Studies have determined that the RA RA and PA pressures may be position with the head of the bed and PA pressures are accurate accurate for patients in the from 0 to 45 degrees. (Level VI: Clinical in this position. 3,5,6,9,14,16,18,28,29 supine position with the head studies in a variety of patient populations of the bed elevated up to and situations to support 60 degrees, 6,18 but additional recommendations.) studies are needed to support this. Only one study 15 supports the accuracy of hemodynamic values for patients in the lateral Procedure continues on the following page Figure 72-7 Note vertical lines drawn from the beginning of the P wave of two of the electrocardiogram (ECG) 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.

10 558 Unit II Cardiovascular System 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, T.S., and Taylor, L.K. [1992]. Hemodynamic Waveform Analysis. Philadelphia: W.B. Saunders.) Procedure positions; other studies 3,11,14,22,27 do not. The majority of studies 1,2,10,13,17,23,26 support the accuracy of hemodynamic monitoring for patients in the prone position; yet two studies demonstrated that prone positioning caused an increase in hemodynamic values. 24,25 2. Run a dual-channel strip of the ECG PA pressures are determined from the Some monitors have the and PA waveform (Fig. 72-9). graphic strip, because the effect of capability of freeze framing ventilation can be identified. waveforms. A cursor can be used to determine pressure measurements. 3. Measure the PA pressure at Measurement is most accurate as the end-expiration. effects of pulmonary pressures are minimized. 4. Identify the QT interval on the Demonstrates ventricular ECG strip. depolarization. 5. Align the QT interval with Compares electrical activity to the PA waveform. mechanical activity.

11 72 Pulmonary Artery Catheter Insertion (Assist) and Pressure Monitoring 559 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 (ECG). 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, T.S., and Taylor, L.K. [1992]. Hemodynamic Waveform Analysis. Philadelphia: W.B. Saunders.) Procedure 6. Identify the scale of the PA tracing. Aids in determining the pressure PA scale is commonly set measurement. at 40 mm Hg. 7. Measure the PA systolic pressure at the This reflects the highest systolic peak of the systolic waveform on pressure. the PA waveform (see Fig. 72-9). 8. Align the end of the QRS complex with The end of the QRS complex the PA waveform (see Fig. 72-9). correlates with ventricular end-diastolic pressure. 9. Measure the PA diastolic pressure This point occurs just before the at the point of the intersection of upstroke of the systolic pressure. this line (see Fig. 72-9). PAWP 1. Position the patient in the supine Studies have determined that the RA RA and PA pressures may be position with the head of the bed and PA pressures are accurate accurate for patients in the from 0 to 45 degrees. (Level VI: Clinical in this position. 3,5,6,9,14,16,18,28,29 supine position with the head studies in a variety of patient of the bed elevated up to populations and situations to support 60 degrees, 6,18 but additional recommendations.) studies are needed to support this. Only one study 15 supports the accuracy of hemodynamic values for patients in the lateral Procedure continues on the following page

12 560 Unit II Cardiovascular System Procedure positions; other studies 3,11,14,22,27 do not. The majority of studies 1,2,10,13,17,23,26 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. 24,25 2. Fill the PA syringe with 1.5 ml of air. More than 1.5 ml of air may rupture the PA balloon and the pulmonary arteriole. 3. Connect the PA syringe to the gate This port is designed for PA balloon valve or stopcock of the balloon port air inflation. of the PA catheter (see Fig. 72-6). 4. Run a dual-channel strip of the ECG The PAW pressures are determined Some monitors have the and PA waveform. from the graphic strip, because capability of freeze framing the effect of ventilation can be identified. waveforms. A cursor can be used to determine pressure measurements. 5. Slowly inflate the balloon with air until A slight resistance is usually felt Only enough air is needed to the PA waveform changes to a PAW during inflation of the balloon. convert the PA waveform to a waveform (Fig ). Overinflation of the balloon can PAW waveform. Thus, the cause pulmonary arteriole infarction entire amount of 1.5 ml of air or rupture, resulting in potentially is not necessarily needed. life-threatening hemorrhage Inflate the PA balloon for no more than Prolonged inflation of the balloon can 8 to 15 seconds (two to four respiratory cause pulmonary arteriole infarction cycles). and rupture, with potentially life-threatening hemorrhage. 12 Figure Change in pulmonary artery pressure (PAP) waveform to pulmonary artery wedge pressure (PAWP) waveform with balloon inflation. The balloon is inflated while observing the bedside monitor for change in the waveform. Balloon inflation (arrow) in patient with normal PAWP.

13 Procedure 72 Pulmonary Artery Catheter Insertion (Assist) and Pressure Monitoring Disconnect the syringe from the Allows air to passively escape from Active withdrawal of air from balloon-inflation port. the balloon. the balloon can weaken the balloon, pull the balloon structure into the inflation lumen, and possibly cause balloon rupture. 8. Observe the monitor as the PAW Ensures adequate balloon deflation. waveform changes back to the PA waveform. 9. Expel air from the syringe. The syringe should remain empty so that accidental balloon inflation does not occur. 10. Reconnect the syringe to the end The syringe that is manufactured for of the balloon-inflation valve. the PA catheter should be connected to the PA line so that it is not lost. This syringe can only be filled with 1.5 ml of air, thus serving as a safety feature to minimize the chance of balloon overinflation. 11. Close the gate valve or stopcock at the Prevents accidental use of the end of the balloon-inflation valve. balloon-inflation valve. 12. Using the dual-channel recorded strip, Compares electrical activity to c waves commonly are not draw a vertical line from the beginning mechanical activity. Two to three present on PAW waveforms of the P wave of one of the ECG waves will be present on the PAW due to the distance the complexes down to the PAW waveform. waveform. pressure needs to travel back Repeat this with the next ECG complex. to the transducer. 13. Align the end of a QRS complex of the Compares electrical activity to ECG strip with the PAW waveform mechanical activity. (Fig ). 14. Identify the a wave (see Fig ). The a wave correlates with the end If only two waves are present, of the QRS complex. The c wave the first wave is the a wave follows the a wave, and the v wave and the second wave is the follows the c wave. v wave. 15. Identify the scale of the PAW tracing. Aids in determining pressure PA scale commonly is set at measurement. 40 mm Hg. 16. Measure the mean of the a wave to The a wave represents atrial If PEEP is being used and obtain the PAWP (see Fig. 72-5). contraction and reflects left the PEEP is more than ventricular filling at end-diastole. 10 cm H 2 O, adjustments in determining the pressures may be necessary. Follow institutional standard. 17. Compare the PADP with the PAWP. The PAWP is commonly 1 to 4 mm Hg less than the PADP. Significant differences between PADP and PAWP may exist for patients with pulmonary hypertension, chronic obstructive lung disease, ARDS, pulmonary embolus, and tachycardia. PADPs that correlate with PAWPs represent left ventricular filling pressures. Procedure continues on the following page

14 562 Unit II Cardiovascular System Figure Obtaining measurement of the pulmonary artery wedge pressure (PAWP). For accurate readings, align the a wave from the PAW waveform with the end of the QRS on the electrocardiogram (ECG) at end-diastole. (From Ahrens, T.S., and Taylor, L.K. [1992]. Hemodynamic Waveform Analysis. Philadelphia: W.B. Saunders.) Procedure 18. Follow PA diastolic pressures if there Ensures accuracy of determination of Minimizes the number of times is a close correlation between PADP left ventricular filling pressures. the PA balloon is inflated. and PAWP. 19. Follow the PAWP if there is greater than Ensures accuracy of measurements. 4 mm Hg of difference between PAWP and PADP. Measurement of Hemodynamic Pressures at End-Expiration 1. Measure all hemodynamic pressures at Atmospheric and alveolar pressures end-expiration to ensure accuracy. are approximately equal at endexpiration. 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. 2. Determine end-expiration by observing Determines accuracy of the rise and fall of the chest during end-expiration. breathing and use graphic hemodynamic, respiratory, or continuous airway pressure waveforms.

15 Procedure 72 Pulmonary Artery Catheter Insertion (Assist) and Pressure Monitoring 563 Determining End-Expiration for the Patient Breathing Spontaneously 1. Record a strip of the PA waveform. A labeled recording aids in In patients who are breathing determination of accurate spontaneously, the normal hemodynamic pressure values. inspiratory:expiratory ratio is approximately 1:2. 2. Note that the pressure waveform dips Pleural pressure decreases down during the inspiratory phase of during spontaneous inspiration, breathing (Fig ). and this decrease is reflected by a fall in the cardiac pressures. 3. Note that the pressure waveform elevates As pleural pressures equalize, the during the expiratory phase of breathing cardiac pressures reflect a more (see Fig ). true normal. 4. Measure the pressure at the end of the Ensures accurate and consistent expiratory phase (see Fig ). pressure measurements. Determining End-Expiration for the Patient Receiving Mechanical Ventilation 1. Record a strip of the PA waveform. A labeled recording aids in determination of accurate hemodynamic pressure values. 2. Note that the pressure waveform elevates As the ventilator delivers a as a breath is delivered by the ventilator breath to the lungs, an increase (Fig ). in pleural pressure results. This increase in pleural pressure causes an increase in intracardiac pressures. 3. Note that the pressure waveform dips As the mechanical breath is exhaled, down as the breath is exhaled pulmonary pressures decrease and (see Fig ). intracardiac pressures are accurately and consistently measured. Procedure continues on the following page 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 will be taken.

16 564 Unit II Cardiovascular System Figure Mechanically ventilated patient (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. Procedure Determining End-Expiration for the Patient Receiving Intermittent Mandatory Mechanical Ventilation 1. Record a strip of the PA waveform. A labeled recording aides in determination of accurate hemodynamic pressure monitoring. 2. If the patient is receiving Ensures accurate determination intermittent mandatory of pressure values. ventilation, measure the pressure during the end-expiration. 3. Note that the pressure As the ventilator delivers waveform elevates as a breath a breath to the lungs, is delivered by the ventilator (Fig ). an increase in pleural pressure results. This increase in pleural pressure causes an increase in intracardiac pressures. 4. Note that the pressure waveform As the mechanical breath dips down as the breath is exhaled, pulmonary is exhaled (see Fig ). pressures decrease and intracardiac pressures are more accurately reflected. 5. Identify the patient s spontaneous This breath may occur just breath (see Fig ). prior to triggered ventilator breaths. 6. Determine end-expiration. Ensures accuracy of measurements.

17 W _072 2/24/05 4:37 PM Page Pulmonary Artery Catheter Insertion (Assist) and Pressure Monitoring 565 Figure IMV mode of ventilation and the effect on the pulmonary artery (PA) waveform. (From Ahrens, T.S., and Taylor, L.K. [1992]. Hemodynamic Waveform Analysis. Philadelphia: W.B. Saunders.) Expected Outcomes Unexpected Outcomes Accurate placement of the pulmonary artery catheter Adequate and appropriate waveforms Ability to obtain accurate information about cardiac pressures Evaluation of information obtained to guide therapeutic interventions Pneumothorax or hemothorax Infection Ventricular dysrhythmias Heart block Misplacement (e.g., carotid artery, subclavian artery) Hemorrhage Hematoma Pericardial or ventricular rupture Venous air embolism Cardiac tamponade Sepsis Pulmonary artery infarction Pulmonary artery rupture Pulmonary artery catheter balloon rupture Pulmonary artery catheter knotting Heparin-induced thrombocytopenia Thrombosis Valvular damage Patient Monitoring and Care Steps Rationale Reportable Conditions These conditions should be reported if they persist despite nursing interventions. 1. Recheck leveling whenever patient position changes. Ensures accurate reference point for the left atrium. Procedure continues on the following page

18 566 Unit II Cardiovascular System Patient Monitoring and Care Continued Steps Rationale Reportable Conditions 2. Zero the transducer during initial Ensures accuracy of the hemodynamic setup or before insertion, if monitoring system; minimizes disconnection occurs between the the risk for contamination transducer and the monitoring cable, of the system. if disconnection occurs between the monitoring cable and the monitor, and when the values obtained do not fit the clinical picture. Follow manufacturer recommendations for disposable systems. 3. Place sterile nonvented caps on all Stopcocks can be a source of stopcocks. Replace with new, sterile contamination. Stopcocks that are caps whenever the caps are removed. part of the initial setup are commonly vented. Vented caps need to be replaced with nonvented caps to maintain sterility. 4. Monitor the pressure transducer Air emboli are potentially fatal. Suspected air emboli system (pressure tubing, transducer, stopcocks, etc.) for air and eliminate air from the system. 5. Continuously monitor hemodynamic Provides for continuous waveform Abnormal hemodynamic waveforms and obtain hemodynamic analysis and assessment of patient waveforms and/or pressures values (pulmonary artery systolic status. pressure [PASP], PADP, RAP) hourly and as necessary with condition changes. 6. Obtain CO, CI, and systemic vascular Monitors patient status. Abnormal hemodynamic resistance and additional parameters parameters or significant immediately after catheter insertion changes in hemodynamic and as necessary per patient condition. parameters 7. Change the hemodynamic monitoring The Centers for Disease Control and system (flush solution, pressure Prevention (CDC) 20 and research tubing, transducers, and stopcocks) findings 19,21 recommend that the every 96 hours. (Level V: Clinical hemodynamic flush system can be studies in more than one or two used safely for 96 hours. This different patient populations and recommendation is based on research situations to support recommendations.) conducted with disposable pressure The flush solution may need to be monitoring systems used for changed more frequently if near peripheral and central lines. empty of solution. 8. Perform a dynamic response test An optimally damped system Overdamped or underdamped (square wave test) at the start of each provides an accurate waveform. waveforms that cannot be shift, with a change of the waveform, corrected with troubleshooting or when the system is opened to air procedures (see Fig. 59-3). 9. Label the tubing with the date and Identifies when the system needs time the system was prepared. to be changed. 10. Maintain the pressure bag or device At 300 mm Hg each flush device will at 300 mm Hg. deliver approximately 1 to 3 ml/hour to maintain patency of the system. 11. Do not fast-flush the catheter for Pulmonary artery rupture may longer than 2 seconds. 8 potentially occur with prolonged flushing of high-pressure fluid.

19 72 Pulmonary Artery Catheter Insertion (Assist) and Pressure Monitoring 567 Patient Monitoring and Care Continued Steps Rationale Reportable Conditions 12. Never flush the PA catheter when Excessive PA pressure may cause the balloon is wedged in the PA damage and/or rupture. pulmonary artery. 13. Use aseptic technique when withdrawing Prevents bacterial contamination from or flushing the PA catheter. of the system. 14. Clear the system, including stopcocks, Blood can become a medium for of all traces of blood after blood bacterial growth. 20 Clots also may be withdrawal. flushed into the catheter if all blood is not eliminated. 15. Maintain sterility and integrity of Any tear in the sleeve will break the Defects in the integrity the plastic sleeve covering the PA sterile barrier, making catheter of plastic sleeve catheter. repositioning no longer possible. 16. Blood products and albumin Viscous blood may occlude the should never be infused through catheter. The accuracy of the PA the PA catheter. monitoring system may be adversely affected. 17. IV fluids are never infused via the PA monitoring is not possible, and a distal lumen of the PA catheter and life-threatening situation can occur are rarely infused via the proximal (e.g., undetected wedged PA catheter). lumen of the PA catheter. 18. Replace gauze dressings every Decreases the risk for infection at the Signs or symptoms of 2 days and transparent dressings at catheter site. The CDC recommends infection least every 7 days. 20 Cleanse the site replacing the dressing when the with an antiseptic solution (e.g., 2% dressing becomes damp, loosened, chlorhexidine-based preparation). soiled, or when inspection of the site is necessary Date, time, and initial the dressing Ensures consistency of dressing change change. and indicates when the next change will occur. 20. Follow institutional standard for Routine use of antimicrobial ointment application of antimicrobial at central venous catheter sites is not ointment to catheter sites. recommended Obtain PA waveform strips to The printed waveform allows place on the patient s chart at the assessment of the adequacy of the start of each shift and whenever waveform, presence of damping, there is a change in the waveform. or respiratory variation. 22. Consider changing PA catheters The CDC recommends that PA Signs and symptoms of every 7 days. catheters do not need to be changed infection. more frequently than every 7 days. 20 The CDC makes no specific recommendation regarding routine replacement of PA catheters that need to be in place for greater than 7 days. 20 Documentation Documentation should include the following: Patient and family education Insertion of the PA catheter External cm marking of PA catheter noted at exit site Patient tolerance of procedure Confirmation of PA catheter placement (e.g., waveforms, chest x-ray) Cardiac rhythm during PA catheter insertion and monitoring Site assessment PA pressures (RA/CVP, PA systolic, diastolic, mean, and PAWP) Waveforms (RA/CVP, PAP, PAWP) CO/CI and SVR Occurrence of unexpected outcomes and interventions

20 568 Unit II Cardiovascular System References 1. Blanch, L., et al. (1997). Short term effects of prone position in critically ill patients with acute respiratory distress syndrome. Intensive Care Med, 23, Brussel, T., et al. (1993). Mechanical ventilation in the prone position for acute respiratory failure after cardiac surgery. J Cardiothorac Vasc Anesth, 7, Cason, C.L., et al. (1990). Effects of backrest elevation and position on pulmonary artery pressures. Cardiovasc Nurs, 26, Chong, B.H. (1995). Heparin-induced thrombocytopenia. British J Haematology, 89, Chulay, M., and Miller, T. (1984). The effect of backrest elevation on pulmonary artery and pulmonary capillary wedge pressures in patients after cardiac surgery. Heart Lung, 13, Clochesy, J., Hinshaw, A.D., and Otto, C.W. (1984). Effects of change of position on pulmonary artery and pulmonary capillary wedge pressure in mechanically ventilated patients. NITA, 7, Cohen, Y., et al. (1998). The hands-off catheter in the prevention of systemic infections associated with pulmonary artery catheter: A prospective study. Am J Respir Crit Care Med, 157, Daily, E.K., and Schroeder, J.S. (1994). Techniques in Bedside Hemodynamic Monitoring. 5th ed. St. Louis: Mosby. 9. Dobbin, K., et al. (1992). Pulmonary artery pressure measurement in patients with elevated pressures: Effect of backrest elevation and method of measurement. Am J Crit Care, 1, Fridrich, P., et al. (1996). The effects of long-term prone positioning in patients with trauma-induced adult respiratory distress syndrome. Anesth Analg, 83, Groom, L., Frisch, S.R., and Elliot, M. (1990). Reproducibility and accuracy of pulmonary artery pressure measurement in supine and lateral positions. Heart Lung, 19, Hannan, A.T., Brown, M., and Bigman, O. (1984). Pulmonary artery catheter induced hemorrhage. Chest, 85, Jolliet, P., Bulpa, P., and Chevrolet, J.C. (1998). Effects of prone position on gas exchange and hemodynamics in severe acute respiratory distress syndrome. Crit Care Med, 26, Keating, D., et al. (1986). Effect of sidelying positions on pulmonary artery pressures. Heart Lung, 15, Kennedy, G.T., Bryant, A., and Crawford, M.H. (1984). The effects of lateral body positioning on measurements of pulmonary artery and pulmonary wedge pressures. Heart Lung, 13, Lambert, C.W., and Cason, C.L. (1990). Backrest elevation and pulmonary artery pressures: Research analysis. Dimensions Crit Care Nurs, 9, Langer, M., et al. (1988). The prone position in ARDS patients. Chest, 94, Laulive, J.L. (1982). Pulmonary artery pressures and position changes in the critically ill adult. Dimensions Crit Care Nurs, 1, Luskin, R.L., et al. (1986). Extended use of disposable pressure transducers: A bacteriologic evaluation. JAMA, 255, O Grady, N.P., et al. (2002). Guidelines for the prevention of intravascular catheter-related infections. Am J Infect Control, 30, O Malley, M.K., et al. (1994). Value of routine pressure monitoring system changes after 72 hours of use. Crit Care Med, 22, Osika, C. (1989). Measurement of pulmonary artery pressures: Supine verses side-lying head-elevated positions. Heart Lung, 18, Pappert, D., et al. (1994). Influence of positioning on ventilation-perfusion relationships in severe adult respiratory distress syndrome. Chest, 106, Pelosi, P., et al. (1998). Effects of the prone position on respiratory mechanics and gas exchange during acute lung injury. Am J Respir Crit Care Med, 157, Voggenreiter, G., et al. (1999). Intermittent prone positioning in the treatment of severe and moderate posttraumatic lung injury. Crit Care Med, 27, Vollman, K.M., and Bander, J.J. (1996). Improved oxygenation utilizing a prone positioner in patients with acute respiratory distress syndrome. Intensive Care Med, 22, Wild, L. (1984). Effect of lateral recumbent positions on measurement of pulmonary artery and pulmonary artery wedge pressures in critically ill adults. Heart Lung, 13, Wilson, A.E., et al. (1996). Effect of backrest position on hemodynamic and right ventricular measurements in critically ill adults. Am J Crit Care, 5, Woods, S.L., and Mansfield, L.W. (1976). Effect of body position upon pulmonary artery and pulmonary capillary wedge pressures in noncritically ill patients. Heart Lung, 5, Additional Readings Anonymous. (1997). Pulmonary artery catheter consensus conference: Consensus statement. Crit Care Med, 25, Ahrens, T.S., and Taylor, L.A. (1992). Hemodynamic Waveform Analysis. Philadelphia: W.B. Saunders. Bridges, E.J., and Woods, S.L. (1993). Pulmonary artery pressure measurement: State of art. Heart Lung, 22, Campbell, M.L., and Greenberg, C.A. (1988). Pulmonary artery wedge pressure at end-expiration. Focus Crit Care, 15, Cason, C.L., and Lambert, C.W. (1993). Positioning during hemodynamic monitoring: Evaluating the research. Dimensions Crit Care Nurs, 12, Daily, E.K. (2001). Hemodynamic waveform analysis. J Cardiovasc Nurs, 15, 6-22, Darovic, G.O. (2002). Hemodynamic Monitoring: Invasive and Noninvasive Clinical Application. 3rd ed. Philadelphia: W.B. Saunders. Ducharme, F.M., et al. (1988). Incidence of infection related to arterial catheterization in children: A prospective study. Crit Care Med, 16, Grap, M.J., Pettrey, L., and Thornby, D. (1997). Hemodynamic monitoring: A comparison of research and practice. Am J Crit Care, 6, Houghton, D., et al. (2002). Routine daily chest radiography in patients with pulmonary artery catheters. Am J Crit Care, 11, Keckeisen, M. (1997). Protocols for Practice: Hemodynamic Monitoring Series Pulmonary Artery Pressure Monitoring. Aliso Viejo, Ca: American Association of Critical-Care Nurses. Kee, L.L., et al. (1993). Echocardiographic determination of valid zero reference levels in supine and lateral positions. Am J Crit Care, 2, Liu, C., and Webb, C. (2000). From the Food and Drug Administration. Pulmonary artery rupture: Serious complication associated with pulmonary artery catheters. Internat J Trauma Nurs, 6, Mermel, L.A., et al. (1991). The pathogenesis and epidemiology of catheter-related infection with pulmonary artery Swan-Ganz catheters: A prospective study utilizing molecular subtyping. Am J Med, 91, 197S-205S. Ott, K., Johnson, K., and Ahrens, T. (2001). New technologies in the assessment of hemodynamic parameters. J Cardiovasc Nurs, 15,