Chapter 9 Pulmonary Artery Catheterization

Rovinder S. Sandhu, MD, Michael D. Pasquale, MD

INTRODUCTION

Pulmonary artery catheterization (PAC) has been the subject of enormous controversy regarding its utility since its introduction by Swan and Ganz and coworkers in 1970.¹ Detailed discussion regarding this controversy is beyond the scope of this chapter. However, a study performed by Connors and colleagues in 1996² comparing outcomes of critically ill patients managed with or without a PAC within the first 24 hours after admission to an intensive care unit (ICU) revealed an association between PAC and an increased relative risk of hospital mortality and increased utilization of resources. This paper reignited the controversy and made clinicians reevaluate the efficacy and safety of the pulmonary artery (PA) catheter. Many studies show no benefit or harm from PAC³^–⁵; others show decreased mortality.^6,⁷ Amid the controversy, physicians continue to use PAC in critically ill patients, although no validated indications exist for its use.

PA catheters are used to provide various hemodynamic parameters. Directly measured data include heart rate, waveforms, cardiac output, pulmonary artery pressures, right atrial pressure (central venous pressure [CVP]), pulmonary arterial occlusion pressure (PAOP; wedge), and mixed venous oxygen saturation. In addition, using these parameters, many other values—including mean arterial blood pressure, body surface area, stroke volume, systemic and pulmonary vascular resistance, ventricular stroke work, and oxygen delivery and consumption—can be calculated.⁸

INDICATIONS ⁹

• Diagnosis of shock states

• Differentiation of high versus low-pressure pulmonary edema

• Diagnosis of primary pulmonary hypertension

• Diagnosis of valvular disease, intracardiac shunts, cardiac tamponade, and pulmonary embolus

• Monitoring and management of complicated acute myocardial infarction

• Assessment of hemodynamic response to therapies

• Management of multiorgan system failure and/or severe burns

• Management of hemodynamic instability after cardiac surgery

• Assessment of response to treatment in patients with primary pulmonary hypertension

• Aspiration of air emboli

In addition, PAC may be useful in perioperative monitoring of high-risk patients undergoing high-risk procedures.

As with any other invasive procedure, PAC has its own inherent technical complications during insertion. The overall risks of complications have been reported to be anywhere from 5% to 15%. These include complications related to venous access and to right heart catheterization and PAC as well as infectious and thrombotic complications.¹⁰

OPERATIVE STEPS

Step 1 Assess patient’s need for pulmonary artery catheterization

Step 2 Review patient’s chart—particularly checking for history of coagulation abnormalities and history of deep venous thrombosis

Step 3 Choose appropriate site for placement (i.e., internal jugular or subclavian)

Step 4 Obtain consent

Step 5 Gather supplies

Step 6 Perform a “time out” between the physician and bedside nurse

Step 7 Prep the patient—including correct patient positioning for particular site

Step 8 Cannulate the vein

Step 9 Place guidewire

Step 10 Place the cordis over the guidewire

Step 11 Remove the guidewire

Step 12 Aspirate blood from the cordis

Step 13 Flush the cordis

Step 14 Flush the ports of the pulmonary artery catheter

Step 15 Attach catheter to transducer and check frequency response

Step 16 Place pulmonary artery catheter through the cordis to 20 cm

Step 17 Inflate balloon and follow until a pulmonary artery occlusion tracing is identified

Step 18 Deflate balloon and identify pulmonary artery tracing

Step 19 Secure catheter

Step 20 Place sterile dressing

Step 21 Check placement with chest x-ray

OPERATIVE PROCEDURE

Prior to placing a PA catheter, one must obtain all necessary equipment and review the patient’s chart.

1. Informed consent should be obtained from the patient or power of attorney.

2. Review the patient’s chart to make certain no contraindications exist (e.g., coagulopathy, tricuspid or pulmonary valve mechanical prosthetics, right heart mass, tricuspid or pulmonary valve endocarditis, history of heparin-induced thrombocytopenia [many PA catheters are heparin-coated; non-coated ones are available], and history of left bundle branch block).

3. An experienced nurse should be available and in the room to assist with the procedure, along with a physician experienced in PAC and waveform analysis.

4. All necessary equipment should be gathered including introducer sheath, PA catheter, transducers, and flushes. In addition, as in central vein catheterization, maximal sterile-barrier precautions should be used (mask, cap, gown, sterile gloves, and a large sterile drape).

5. Although most patients are critically ill or in the operating room while having a PA catheter placed, appropriate sedation and local anesthetic should be used.

The first step in PAC is to obtain venous access. A PA catheter can be introduced most commonly through internal jugular, subclavian, and femoral sheath intro-ducers. If needed, the external jugular vein or antecubital fossa can be used. Each site has specific risks. Review Chapter 8, Central Vein Catheterization, for insertion of introducer sheaths and complications in accessing these sites. Each site has its own advantages and disadvantages for subsequently placing a PA catheter.

1. Internal jugular vein

a. Lower risk of pneumothorax.

b. Right-sided offers the most direct approach to the heart.

c. Left-sided offers a less direct approach to the heart and may make achieving a PAC more difficult.

d. Risk of carotid puncture and dilation with a large-bore sheath introducer may lead to cardiovascular accident or neck hematoma and loss of airway.

2. Subclavian vein

a. Higher risk of pneumothorax.

b. Usually high rate of successful PAC in right or left-sided placements.

c. Subclavian arterial puncture may be more difficult to control, especially in coagulopathic patients, and may lead to hemothorax.

3. Femoral vein

a. No risk of pneumothorax.

b. Arterial puncture is easier to control with pressure, although peripheral embolization is of concern.

c. Difficult PAC; fluoroscopy may be useful.

d. History of internal jugular vein catheterization filter is an absolute contraindication.

4. External jugular and antecubital approaches

a. Usually require fluoroscopy.

b. Difficult for PAC, although published rates of success are in excess of 75%.^11,¹²

c. Higher rates of thrombosis in peripheral veins.

Complications of central vein catheterization are discussed in Chapter 8, Central Vein Catheterization. These include pneumothorax, hemothorax (grade 2), thoracic duct injury (grade 2/3), arterial puncture, possible pseudoaneurysm formation or arteriovenous fistula formation (grade 1/2/3), air embolism (grade 2/5), cardiac perforation with associated cardiac tamponade (grade 3/4/5), thrombus (grade 1/2/5), and infections (grade 1).

Once central vein catheterization is achieved, one can prepare for PAC. Many different PA catheters exist; they all have some similarities (Fig. 9-1):

1. Yellow port—PA port

2. Blue port—CVP port

3. Pink port—1.5-cc balloon port

4. Clear port—infusion port (if available)

5. PA catheter marked at 10-cc intervals for monitoring placement