CURRENT Essentials of Critical Care.pdf

Chapter 1 Monitoring & Support 19■■Pulmonary Artery CatheterEssential Concepts• Measures pressure in pulmonary artery (PA), central venouspressure (CVP), and pulmonary artery wedge pressure (PAWP)(estimate of left atrial pressure)• Most measure cardiac output using thermodilution; some withoximeter probe for mixed venous O 2 saturation• Blood can be sampled from distal tip (mixed venous blood) orfrom proximal port (central venous blood)• Calculate cardiac index (CI), systemic vascular resistance(SVR), and pulmonary vascular resistance (PVR)Essentials of Management• Indications: cardiogenic shock, cardiogenic pulmonary edema,acute myocardial infarction with hemodynamic compromise,cardiac tamponade• May be helpful in patients with acute hypoxemic respiratoryfailure, sepsis and septic shock, but value unknown• Use caution in estimating PAWP with tachycardia, pulmonaryhypertension, large intrathoracic pressure swings during respiratorycycle• Measure pressures at “end-expiration”• Inflate balloon only enough to achieve “wedge” position (do notexceed 1.5 mL)• Optimal PAWP 18 mm Hg in patient with cardiogenic shock• Increased pulmonary edema (normal lungs) when PAWP 25mm Hg; in noncardiogenic pulmonary edema, PAWP shouldbe 10 mm Hg, if patient is hemodynamically stable• Mixed venous PO 2 30 mm Hg associated with poor organ oxygenationand lactic acidosis; but 30 mm Hg is not a reliablesign of adequate oxygenation• Relative contraindications: coagulopathy, thrombocytopenia,bacteremia, anticipated use of thrombolytic agents• Complications: bleeding, pneumothorax, arrhythmias, heartblock and bradycardia, pulmonary artery, infection■ PearlIn cardiac tamponade, look for equalization of RA and LA pressuresby displaying pressure waveforms on same screen at same scale.ReferenceCruz K, Franklin C: The pulmonary artery catheter: uses and controversies.Crit Care Clin 2001;17:271-91. [PMID: 11450316]