Swan-Ganz (Pulmonary Artery) Catheterization

CHAPTER 215 Swan-Ganz (Pulmonary Artery) Catheterization



Stuart Forman


For over 30 years the use of the balloon-flotation, flow-directed pulmonary artery (PA) thermodilution (Swan-Ganz) catheter has symbolized modern care of the critically ill patient. However, in the past 10 years several studies have found that the PA catheter does not reduce morbidity or mortality. These studies are summarized in the Cochrane Collaborative paper that states “even though the trials measured numbers of deaths in each group at different points of time, all reported that there were no differences between patients who did and did not have a PA catheter inserted” (Harvey and colleagues, 2006). Another meta-analysis in the Journal of the American Medical Association similarly showed that “the use of PA catheter neither increased overall mortality in the hospital nor conferred benefit” (Shah and colleagues, 2005).


Alternatively, early goal-directed therapy (EGDT, which uses a regular central line and monitors central venous pressure [CVP] and central venous oxygen saturation [SCVO2]) in patients with septic shock demonstrated impressive survival rates in a landmark study in 2001 (Rivers and colleagues, 2001). The standard therapy group had an in-hospital mortality rate of 46.5%, compared with 30.5% for those assigned to EGDT. Protocol patients were resuscitated to a CVP of 8 to 12 mm Hg and a mean arterial pressure of 65 mm Hg. If at this point their SCVO2 was below 70%, packed red cells were transfused to a hematocrit of 30% and dobutamine added, if necessary, until their SCVO2 normalized to 70%. If still not there, mean arterial pressure was titrated to 65 mm Hg with either norepinephrine or dopamine (Rivers and colleagues, 2001). Subsequent trials have validated these results with similar or better findings (Otero and colleagues, 2006). As a result, many intensive care units have moved away from the PA catheter and are using less invasive methods such as central lines for CVP monitoring and echocardiograms to evaluate cardiac function (see Chapter 90, Echocardiography, and Chapter 225, Emergency Department, Hospitalist, and Office Ultrasonography [Clinical Ultrasonography]). There is even exciting new technology available that provides continuous measurement of cardiac output using just a radial arterial line. That said, PA catheters still have a major role in critical care. Pinsky and Vincent (2005) proposed an algorithm for use of PA catheters (Fig. 215-1); their criteria for initiation of the protocol “would be ongoing circulatory shock despite initial fluid resuscitation efforts or, in the setting of normotension, persistent tachycardia, metabolic acidosis, lactic acidosis, altered mental status, or decreased urine output, since all these are signs or indirect markers of inadequate tissue perfusion.” Further study is needed to compare PA catheter-derived outcomes with those using a mere central line. As of this writing, PA catheters still remain an important, although less frequently used, assessment tool in critical care.


image

Figure 215-1 Diagnostic and therapeutic algorithm based on mixed venous oxygen saturation (SVO2) measurements: therapeutic options to be considered are presented in the rectangles. SaO2, arterial oxygen saturation; O2ER, oxygen extraction ratio; PEEP, positive end-expiratory pressure; PAOP, pulmonary artery occlusion pressure; image, oxygen consumption.


(From Pinsky MR, Vincent JL: Let us use the pulmonary artery catheter correctly and only when we need it. Crit Care Med 33:1119–1122, 2005.)


This chapter was written for the primary care clinician preparing to insert a PA catheter. All PA catheters generate data such as cardiac output, pulmonary artery wedge pressure, systemic vascular resistance, and stroke work index; therefore, clinicians using PA catheters should be capable of interpreting and acting on these and other results. Many PA catheters are capable of continuously monitoring cardiac output and mixed venous oxygen saturation (SVO2). Further specialized catheters often provide a port or built-in electrode for pacing, four lumens, or the ability to gather specific data regarding right ventricular function. These specialized catheters are beyond the scope of this chapter.


Although many clinicians are proficient with similar procedures and may have cross-over skills, beginners should first observe PA catheter placement several times. Attempts to place the first few catheters should be supervised by a trained, skilled, and experienced clinician. After the clinician gains mastery of the skill of insertion, further study and use of the catheter should increase his or her skills, interest, knowledge, and abilities in the maintenance of a PA catheter as well as in obtaining data. Attending courses devoted to the technology will further enhance proficiency, especially for the subtler applications.



Indications



• Refractory acute respiratory distress syndrome (ARDS) or pulmonary edema, especially in patients with renal failure

• Severe hypoxemia requiring high levels (>10 cm) of positive end-expiratory pressure (PEEP)

• Presence of hemodynamic deterioration due to a mechanical complication (e.g., differentiate between mitral regurgitation and acute ventricular septal defect)

• Evaluation of left ventricular function if echocardiogram not available

• Suspected right ventricular dysfunction or infarction

• Preoperative optimization of extremely high-risk surgical patients

• Oxygen delivery and consumption assessment

• The evaluation of and drug titration for severe pulmonary hypertension


Monitoring



• Titration of drugs or other interventions in a highly unstable patient (e.g., vasodilators, inotropes, pacemaker)

• Refractory heart failure

• Hemodynamically unstable patient unresponsive to conventional therapy

• Unstable myocardial infarction with severely decompensated heart failure

• Right-sided heart failure resulting from severe obstructive lung disease, ARDS, or pulmonary embolism

• Refractory sepsis

• Fluid management in certain complex situations (e.g., shock, postoperative state, ARDS, acute renal failure, intraoperative)


Therapeutic



• Pacing

• Aspiration of air emboli during seated neurosurgery


Contraindications


Contraindications are the same as those for central venous catheterization (see Chapter 211, Central Venous Catheter Insertion), plus the following relative contraindications:


• Diagnostic information could be provided by less invasive means (e.g., echocardiography, a therapeutic trial of fluid administration in the hypovolemic patient)

• Prosthetic right heart valve

• Cardiac-paced patient (temporary, internal, or permanent)*

• Severe hypotension

• Known pulmonary hypertension

• Highly unstable arrhythmias (especially ventricular)

• Right-sided endocarditis or mural thrombus

• Highly unstable respiratory status

• Lack of nursing staff or clinicians trained in use of PA catheters

• Lack of a compatible pressure monitoring apparatus

• Allergy to any component of the catheter (e.g., latex)

note: If the underlying relative contraindication can be altered, catheterization may be worth the risk if there are no alternatives.



Equipment



• Central venous access with an 8.5-Fr percutaneous sheath introducer kit (see Chapter 211, Central Venous Catheter Insertion)

• Radiopaque PA catheter (7 to 7.5 Fr for adults; Fig. 215-2) with syringe for balloon inflation, occlusive caps for each port, and catheter protective shield
image

Figure 215-2 Balloon-tipped thermodilution catheter.


note: Standard thermodilation catheters now usually have four lumens. The distal lumen at the tip measures PA and PA occlusion pressures, and is used for blood sampling. A more proximal lumen (injectate) is used for injecting a thermal bolus for cardiac output measurement (if your Swan-Ganz catheter does not have continuous cardiac output capability). The third lumen is a proximal infusion port for medications; this port may also be used for a thermistor (electrical connection). A fourth lumen is used to inflate the balloon. There may be additional proximal lumens with ports. Catheters coated with chlorhexidine or heparin are also available to reduce the risk of infection and thrombosis, respectively.


• Pressure transducer and monitor (Fig. 215-3)

• High-pressure tubing, connectors, and two three-way stopcocks

• Heparinized saline flush system

• Povidone–iodine solution

• Sterile gowns, drapes, gloves, masks, and goggles

• Surgeon’s cap

• Guidewire if changing central line to an introducer sheath (make sure it is the correct diameter and long enough to properly fit through both catheters)

• Suture and sterile dressing for site

• Supplemental oxygen

• Continuous pulse oximetry, cardiac, and blood pressure monitoring

• Fully stocked code cart and defibrillator nearby

image

Figure 215-3 Pulmonary artery catheter setup.



Preprocedure Patient Preparation


Because PA catheterization is usually an emergency procedure, written informed consent cannot always be obtained. However, explain the indications, risks, benefits, and any available alternatives to the patient and the family, if possible. If the consent is implied, it should be documented. If time allows, the patient or family should sign for informed consent. Venous access may be established by the procedure outlined in Chapter 211, Central Venous Catheter Insertion. As delineated in Chapter 216, Temporary Pacing, catheterization of the right internal jugular vein provides the most direct access to the right atrium and ventricle, but its use may restrict patient mobility. The broad curve of the left subclavian vein may make it more difficult to traverse than the right internal jugular, but it is a reasonable second choice. The left internal jugular and right subclavian veins are acceptable alternatives. The femoral vein is another option, but it is infrequently used and often necessitates the use of fluoroscopy to properly advance the catheter. The external jugular, axillary, and basilic veins are additional options, but are also often difficult to traverse.



Technique



Before Insertion and General Guidelines



1 Supplemental oxygen should be supplied. If the patient is on a ventilator, the ventilatory settings and alarms should be checked. The endotracheal tube should be secured and suctioned.

2 Before the heart undergoes invasive monitoring or an area of the heart is traversed for any reason, record a baseline electrocardiogram (ECG).

3 A “time out” should be taken before this (and any) procedure to make sure you have the right procedure, site, and patient.

4 Because this procedure may induce arrhythmias, an additional, separate intravenous access site should be available. The introducer sheath has a separate intravenous access site if no other access is available.

5 To prevent the loss of a guidewire in a patient, never let go of the guidewire during catheter manipulation.

6 Observe strict sterile technique. Scrub after donning hair cover, goggles or eye protection, mask, and gown; wear sterile gloves and maintain sterile technique throughout the procedure. Optimally, the entire neck and clavicular area are prepared with povidone–iodine if the internal jugular or subclavian routes are to be used; a similarly sized area should be prepared if another route is to be used. Drape as large of an area as possible, including the majority of the patient and the bed. A three-quarter sheet works well for this purpose. Follow universal blood and body fluid precautions.


Conversion to a Sheath or an Introducer


If the venous catheter in place is a multilumen catheter or the single-lumen sheath is not large enough to accept the PA catheter, it must be converted. Use an 8.5-Fr introducer sheath for a 7- or 7.5-Fr PA catheter.


1 Insert a guidewire of proper diameter and sufficient length through the existing venous access line. Always maintain control of the guidewire. (Letting go could allow it to slip into the vein and embolize.) Carefully remove the existing venous access line (catheter or sheath) over the guidewire.

Related posts:

  1. Electrical Cardioversion
  2. Umbilical Vessel Catheterization
  3. Earlobe Repair
  4. Insertion and Removal of Implanon

Stay updated, free articles. Join our Telegram channel
Tags:
May 14, 2017 | Posted by in GENERAL & FAMILY MEDICINE | Comments Off on Swan-Ganz (Pulmonary Artery) Catheterization

Full access? Get Clinical Tree
Get Clinical Tree app for offline access