BEDSIDE HEMODYNAMIC MONITORING Flashcards
What is a Swan-Ganz catheter?
A Swan-Ganz catheter is a soft, flexible catheter with an inflatable balloon at its tip used in right-sided heart catheterization.
How many lumens does the most common Swan-Ganz catheter have?
The most common Swan-Ganz catheter has four lumens.
What is the function of the distal port in a Swan-Ganz catheter?
The distal port allows for measurement of pulmonary artery (PA) pressure when the balloon is deflated and pulmonary artery wedge pressure (PAWP) when inflated.
What is measured using the thermocouple in a Swan-Ganz catheter?
Cardiac output (CO) is measured using the temperature-sensing thermocouple.
What can be directly measured with a Swan-Ganz catheter?
Direct measurements include vascular pressures and oxygen saturations, CO, and systemic venous oxygen saturation (SvO2).
How is a Swan-Ganz catheter inserted?
Venous access is obtained by introducing an 8 French sheath into the internal jugular or subclavian vein, followed by passing a 7.5 French Swan-Ganz catheter through the sheath.
What does the a wave in pressure waveforms correspond to?
The a wave is produced by atrial contraction and follows the electrical P wave on ECG.
What indicates that the Swan-Ganz catheter is in the wedge position?
An atrial tracing reflecting left atrial pressure will be seen when the catheter is in the wedge position.
What does the PAWP approximate?
The pulmonary artery wedge pressure (PAWP) approximates left atrial pressure.
How is cardiac output determined using thermodilution?
10 mL of normal saline is injected into the right atrium, causing a drop in temperature that is measured continuously.
What is the Fick method used for?
The Fick method is used to calculate cardiac output based on oxygen consumption and arteriovenous oxygen difference.
What are normal values for right atrial pressure?
Normal values for right atrial pressure are 0–6 mm Hg.
What clinical situations indicate the use of a Swan-Ganz catheter?
Indications include heart failure/shock, acute myocardial infarction, and perioperative management in high-risk patients.
True or False: The Swan-Ganz catheter is indicated for routine management of pulmonary edema.
False
What is pulmonary hypertension defined as?
Pulmonary hypertension (PH) is defined as a mean pulmonary artery pressure ≥20 mm Hg.
Fill in the blank: The Swan-Ganz catheter is primarily used for _______.
right-sided heart catheterization.
What are the normal values for pulmonary artery wedge pressure?
Normal values for pulmonary artery wedge pressure are 6–12 mm Hg.
What can cause discordance between pulmonary capillary wedge pressure and left ventricular end-diastolic pressure?
Common causes include mitral stenosis and pulmonary vein stenosis.
What measurement is indicated by the v wave in pressure waveforms?
The v wave is caused by venous filling of the atrium during ventricular systole.
What is the significance of the area under the curve in thermodilution?
The area under the curve is inversely related to cardiac output.
What does the y descent in pressure waveforms indicate?
The y descent is produced by rapid atrial emptying when the tricuspid valve opens at the onset of diastole.
What is the purpose of fluoroscopy during Swan-Ganz catheter placement?
Fluoroscopy is used to confirm that the catheter is in a distal pulmonary arteriole.
What are the derived hemodynamic parameters from a Swan-Ganz catheter?
Derived parameters include cardiac index, stroke volume index, and vascular resistances.
What is a major randomized trial regarding Swan-Ganz catheters in heart failure patients?
The ESCAPE trial showed no significant difference in mortality and days out of hospital at 6 months.
What is pulmonary hypertension (PH) defined as?
A mean pulmonary artery pressure (mPAP) of ≥20 mm Hg
What are the three types of pulmonary hypertension?
- Precapillary PH
- Postcapillary PH
- Combined pre- and postcapillary PH
What is required to diagnose and assess the severity of pulmonary arterial hypertension?
Swan-Ganz measurement
How is pulmonary vascular resistance (PVR) calculated?
PVR = (mean PA - PCWP) / cardiac output
In what situations are Swan-Ganz measurements particularly used?
- Assess reversible PH
- Determine eligibility for calcium-channel blockers
- Diagnose heart failure with preserved ejection fraction (HFPEF)
What defines a vasodilatory response in pulmonary arterial hypertension?
Reductions in mean PA pressures by ≥10 mm Hg to values ≤40 mm Hg
What agents are used to assess response in pulmonary arterial hypertension?
- Inhaled nitric oxide
- Adenosine
- Epoprostenol
What is a characteristic finding in pericardial tamponade as seen on Swan-Ganz catheterization?
Equalization of diastolic pressures across all chambers
What are absolute contraindications for placement of a Swan-Ganz catheter?
- Right-sided endocarditis
- Mechanical tricuspid or pulmonic valve prosthesis
- Presence of thrombus or tumor in a right-sided heart chamber
What are relative contraindications for placement of a Swan-Ganz catheter?
- Coagulopathy
- Recent implantation of a permanent pacemaker or cardioverter defibrillator
- Left bundle branch block
- Bioprosthetic tricuspid or pulmonic valve
What hemodynamic parameters can differentiate different etiologies of shock?
Parameters vary by etiology, including RA, RV, PA, PCWP pressures and cardiac output
What is a diagnostic indicator of an atrial septal defect using Swan-Ganz catheterization?
A step-up in mean oxygen saturation of 7% between the caval chambers and the right atrium
What complications are associated with the use of a Swan-Ganz catheter?
- Bleeding
- Infection
- Transient right bundle branch block
- Complete heart block
- Ventricular tachyarrhythmias
- Pulmonary infarction
- Thrombophlebitis
- Endocarditis
- Catheter knotting
How can the complications of Swan-Ganz catheterization be minimized?
- Use fluoroscopy for placement
- Remove catheter after first data set
- Minimize duration of catheter placement
- Limit use of introducer side arm for medications
- Ensure trained personnel manipulate the catheter
- Obtain daily chest radiographs
What should be checked if the wedge tracing is abnormal?
- Check chest radiograph for catheter position
- Aspirate and flush the catheter
- Check all connecting lines and stopcocks
- Confirm pressure transducers are zeroed
- Check balloon inflation
What should be checked if the cardiac output does not make sense?
- Average at least three values
- Verify catheter tip position via chest radiograph
- Ensure computer calibration is correct
