When are pulmonary artery catheters (PACs) recommended for use in critically ill patients?

Pulmonary Artery Catheter Use in Critically Ill Patients

Routine use of pulmonary artery catheters (PACs) is not recommended in critically ill patients, but selective use may be considered when severe hemodynamic abnormalities that significantly affect management cannot be corrected or adequately assessed before surgery or with non-invasive methods. 1

When PACs Should NOT Be Used

Routine placement is contraindicated in the following scenarios:

• Unselected critically ill patients, even those at elevated risk 1
• Patients undergoing noncardiac surgery with standard perioperative risk 1
• Patients with sepsis-induced ARDS who do not require specific pulmonary vascular resistance measurements 1
• Low-risk surgical patients with stable hemodynamics 1

The evidence against routine use is strong: a randomized trial of 1,994 high-risk surgical patients (ASA class III-IV) showed no mortality or morbidity benefit, with an increased incidence of pulmonary embolism in the PAC group 1. A systematic review of 5 studies (n=2,395) confirmed that PAC-guided management did not alter perioperative outcomes compared to central venous pressure monitoring 1.

When PACs MAY Be Considered (Class IIb Recommendation)

PAC placement may be reasonable in specific high-acuity situations where hemodynamic data will directly alter management:

Specific Clinical Scenarios:

• Decompensated heart failure with persistent severe symptoms despite initial therapy 1
• Severe valvular disease (mitral regurgitation, tricuspid regurgitation) when non-invasive assessment is inadequate 1, 2
• Combined shock states requiring differentiation of cardiogenic, distributive, or mixed etiologies 1
• Severe pulmonary hypertension when accurate pulmonary vascular resistance measurement is needed for therapeutic decisions 1, 2
• Cardiogenic shock complicating acute myocardial infarction to characterize hemodynamics and guide inotrope/vasopressor therapy 2
• Severely injured trauma patients in shock, particularly those of advanced age 1

Critical Prerequisites for Use:

The decision must satisfy all three parameters 1:

1. Patient disease severity: Hemodynamic abnormalities that cannot be corrected before surgery or adequately characterized non-invasively
2. Surgical procedure: Major operations with significant intraoperative/postoperative fluid shifts
3. Practice setting: Demonstrated expertise in PAC insertion, data acquisition, and interpretation by the clinical team

Key Clinical Pitfall

The PAC is a monitoring device, not a therapeutic intervention. 3, 4 Outcome benefit depends entirely on linking the hemodynamic data to evidence-based treatment protocols. Studies show that physicians and nurses frequently misinterpret PAC waveforms and derived data 5, which may explain why observational studies suggested harm despite the device being neutral in randomized trials. Without expertise in interpretation and a clear management algorithm based on PAC data, placement provides no benefit and exposes patients to procedural risks (arrhythmias, venous thrombosis, pulmonary artery rupture, catheter-related infections) 2.

Alternative Approaches

Less invasive monitoring should be prioritized when adequate for clinical decision-making:

• Transthoracic or transesophageal echocardiography for cardiac function and volume status assessment 3, 6
• Transpulmonary thermodilution for cardiac output monitoring 3
• Central venous pressure monitoring for basic volume assessment in lower-risk patients 1

Special Populations

In septic shock patients, PAC use did not improve outcomes in randomized trials and is not recommended for routine management 1. However, in selected cases with refractory shock and pulmonary hypertension where therapeutic decisions hinge on pulmonary vascular resistance measurements, PAC may provide diagnostic value 1.

In perioperative cardiac patients, the 2024 AHA/ACC guidelines maintain that PAC may be considered only when underlying cardiovascular conditions (decompensated HF, severe valvular disease, pulmonary hypertension) significantly affect hemodynamics and cannot be corrected preoperatively 1.