Indications contraindications and complications of pulmonary artery catherisation

One may feel an understandable reluctance to subject one's fragile patient to an investigation which has received such terrible publicity. However, one must remember: PACs don't kill people, people kill people. In the wrong hands even a peripheral cannula is a lethal weapon.

Indications for insertion of a PA catheter

There are no hard indications, per se. The decision should rest on the need to answer a specific question about the haemodynamically unstable patient, which cannot be answered with a less invasive technique. Essentially, you would ask of the PAC, “Why is my patient hypotensive? Should I fill my patient more, or should I try to push the vasopressors? Is there room to move with fluids?”

• Cardiac output measurement especially in a patient with arrhythmia or aortic balloon pump, where PiCCO cant be used
• Unequal right and left ventricular failure
• Complex haemodynamic instability, some combination of obstructive, distributive, cardiogenic and hypovolemic shock
• To differentiate cardiogenic pulmonary edema from non-cardiogenic
• To guide use of vasopressors, inotropes, fluids and diuretics – when the patient has a haemodynamic problem combined with pulmonary oedema and ventricular dysfunction.

• To titrate pulmonary antihypertensives in ARDS (like nitric oxide and prostacyclin)

A good 2009 review article on the historical changes in the utility of the PA catheter presents a list of "modern" indications, which resembles the following:

• Cardiogenic shock during supportive therapy
• Discordant right and left ventricular failure
• Severe chronic heart failure requiring inotropic, vasopressor, and vasodilator therapy
• Suspected “pseudosepsis” (high cardiac output, low systemic vascular resistance, elevated right atrial and pulmonary capillary wedge pressures)
• Potentially reversible systolic heart failure such as fulminant myocarditis and peripartum cardiomyopathy
• Haemodynamic differential diagnosis of pulmonary hypertension
• To assess response to therapy in patients with precapillary and mixed types of pulmonary hypertension
• Cardiac / pulmonary transplantation workup

Contraindications

• Tricuspid or pulmonary valve prosthesis  which can be damaged
• Tricuspid or pulmonary valve vegetations  which can be dislodged
• Endocarditis in general
• Right heart mass (be it tumor or clot)
• Delicate structures in the right heart (eg. transvenous pacing wire lead)
• Infective endocarditis of the tricuspid or pulmonary valve
• Severe tricuspid or pulmonic stenosis
• Anything that increases the risk of perforation, eg. extremely dilated thinned atrium or ventricle

Complications

• Same as CVC:
  • Perforation of SVC
  • Haemothorax, pneumothorax
  • Atrial fibrillation
• Unique to PA catheter
  • Ventricular Arrhythmia
  • Thromboembolic events (the catheter is a nidus for clot formation)
  • Mural thrombi in the right heart (up to 30%)
  • Air embolism from ruptured balloon
  • Pulmonary infarction
  • Endocarditis of the pulmonary valve ( 2%)
• Right bundle branch block
• Pulmonary artery rupture: 0.2% risk,  30% mortality
  • Management:
    • Lay the patient ruptured side down
    • Intubate them with a double-lumen tube
    • Increase the PEEP to put pressure on the wound
    • Repair in cardiothoracic theatre
  • Risk factors: pulmonary hypertension, mitral valve disease, anticoagulants and age over 60
• Damage to the valves
  •  Never pull the catheter back with the balloon inflated! You could tear the valve leaflets
• Knotting on structures or on itself ( ~ 1%)
  • If it has gone into the right ventricle by 25-30cm and its still not in the pulmonary artery, you start to worry
  • If you already have LBBB, this causes complete heart block
  • If you are lucky, it is a transient phenomenon and you only need to pace them transcutaneously for a brief period. If you are unlucky, you have injured the AV node, and the patient needs prolonged transvenous pacing