Pulmonary Artery Catheter

R.Srihari

• Introduction• Physiologic Measurements• Indications• Contraindications• Preparation• Technique• Interpretation of hemodynamic values and

waveforms• Complications

Introduction

• Pulmonary artery catheters (also called as Swan-Ganz catheter) are used for evaluation of a range of condition

Although their routine use has fallen out of favour, they are still occasionally placed for management of critically ill patients

Physiological Measurements

• Direct measurements of the following can be obtained from an accurately placed pulmonary artery catheter(PAC)

– Central Venous Pressure(CVP)– Right sided intracardiac pressures(RA/V)– Pulmonary artery pressure(Pap)– Pulmonary artery occlusion pressure (PAOP)– Cardiac Output– Mixed Venous Oxygen Saturation(SvO2)

• Indirect measurements that are possible:– Systemic Vascular Resistance– Pulmonary Vascular Resistance– Cardiac Index– Stroke volume index– Oxygen delivery– Oxygen uptake

Indications

• Diagnostic:– Differentiation among causes of shock– Differentiation between mechanisms of

pulmonary edema– Evaluation of pulmonary hypertension– Diagnosis of pericardial tamponade– Diagnosis of right to left intracardiac shunts– Unexplained dyspnea

• Therapeutic:– Management of perioperative patients with unstable

cardiac status– Management of complicated myocardial infarction– Management of patients following cardiac surgery/high risk

surgery– Management of severe preecclampsia– Guide to pharmacologic therapy– Burns/ Renal Failure/ Heart failure/Sepsis/ Decompensated

cirrhosis– Assess response to pulmonary hypertension specific

therapy

Contraindications

• Absolute:

• Infection at insertion site

• Presence of RV assist device

• Insertion during CPB• Lack of consent

• Relative:

• Coagulopathy• Thrombocytopenia• Electrolyte disturbances (K/Mg/Na/Ca)• Severe Pulmonary HTN

Making decision to place pulmonary artery catheter

• In critically ill or perioperative patients

decision to place a pulmonary artery catheter should be based on patient’s hemodynamic status or diagnosis

that cannot be answered satisfactory by clinical or non-invasive assessment

Preparation

• Patient has to be monitored with continuous ECG throughout the procedure, in supine position regardless of the approach

• Aseptic precautions must be employed

• Cautions should be taken while cannulating via IJV/ Subclavian vein

• Equipments:– 2% chlorhexidine skin preparation solution– Sterile gown, gloves, face shield and cap– Sterile gauze pads – 1% lidocaine -5 cc– Seeker needle 23G– Introducer needle 18G– J-tip guidewire– Transduction tubing– Sterile catheter flush solution– Sheath– Pulonary catheter– Sterile sleeve for catheter– 2-0 silk suture– Sterile dressing

Technique1. Aseptic precautions undertaken2. Local infiltration done3. Check balloon integrity by inflating with 1.5ml of

air 4. Check lumens patency by flushing with saline 0.9% 5. Cover catheter with sterile sleeve provided6. Cannulate vein with Seldinger technique7. Place sheath 8. Pass catheter through sheath with tip curved

towards the heart

9. Once tip of catheter passed through introducer sheath inflate balloon at level of right ventricle

10. The progress of the catheter through right atrium and ventricle into pulmonary artery and wedge position can be monitored by changes in pressure trace

11. After acquiring wedge pressure deflate balloon

• Important tip:– When advancing catheter- always inflate tip– When withdrawing catheter- always deflate– Once in pulmonary artery - NEVER INFLATE

AGAINST RESISTANCE - RISK OF PULMONARY ARTERY RUPTURE

Interpretation of hemodynamic values and waveforms

• Ensuring accurate measurements:– Zeroing and Referencing– Correct placement– Fast flush test

• Zeroing and Referencing:– PAC must be appropriately zeroed and referenced

to obtain accurate readings in supine position/30 degrees semi-recumbent position

• Correct placement :– By either pressure waveform/ fluoroscopic

guidance

• Rapid flush test:

Catheter waveforms and pressures

• Pressure waveforms can be obtained from – Right atrium– Right ventricle – Pulmonary artery

• Right atrium:– In presence of a a competent tricuspid valve, RA

pressure waveform reflect both• Venous return to RA during ventricular systole• RV End Diastolic Pressure

– Normal RA pressure: 0-7 mmHg

• Elevated RA pressure:– Diseases of RV( infarction/ cardiomyopathy)– Pulmonary hypertension– Pulmonic stenosis– Left to right shunts– Pericardial diseases– LV systolic failure– Hypervolemia

• Differentiating among etiologies depends on – Clinical– Radiographical– Echocardiographic features

+PAC findings

Eg: Increased RA Pressure and Mean pulmonary Pressure PAH Increased RAP and Normal Pa pressures RV disease/ Pulmonary stenosis

• Abnormal RA waveforms:– Tall v waves: Tricuspid Regurgitation– Giant/ cannon a waves: • Ventricular tachycardia• Ventricular pacing • Complete heart block• Tricuspid stenosis

– Loss of a waves:• Atrial fibrillation/ Atrial flutter

• Right Ventricle:– Transitioning from SVC or RA to RV:• Once balloon is inflated in the SVC/RA the catheter is

slowly advanced

When catheter tip is across tricuspid valve pressure waveform changes and systolic pressure increases

• 2 pressures are typically measured in right ventricular pressure waveform– Peak RV systolic pressure 15-25mmHg– Peak RV diastolic pressure 3-12 mmHg

• As a general rule elevations in RV pressure:– Diseases increasing pulmonary artery pressure– Pulmonic valve disorders– Diseases affecting right ventricle

• Pulmonary vascular and pulmonary valve disorders a/w increased RV systolic pressures

• RV disorders – ischemia/infarction/failure – a/w increased RV End diastolic pressure

• Pulmonary artery:– The risk of arrhythmias is greatest while catheter tip is

in RV

Thus, catheter should be advanced from RV to PA without delay

– When catheter tip passes pulmonary valve Diastolic pressure increases and characteristic dichrotic notch appears in waveform

• Normal pulmonary artery pressures:– Systolic 15-25mmHg– Diastolic 8-15 mmHg– Mean 16 (10-22mmHg)

• Main components of PA tracing:– Systolic and Diastolic pressure– Dichrotic notch(due to closure of pulmonic valve)

• Increase in mean pulmonary pressure:– Acute:

• Venous Thromboembolism• Hypoxemia induced Pulmonary Vasoconstriction

– Acute on Chronic:• Hypoxemia induced pulm VC in patient with chronic

cardiopulmonary disease

– Chronic:• Pulmonary hypertension

• Types of PHT:– Primary– Due to Heart Disease– Due to Lung Disease– Due to chronic venous thromboembolism– Miscellaneous ( Sickle Cell Anemia)

Pulmonary arterial occlusion pressure

• Once catheter tip has reached PA, it should be advanced until PAOP is identified by decrease in pressure and change in waveform

The balloon should then be deflated and PA tracing should reappear

If PCOP tracing persists catheter should be withdrawn with definitive PA tracing obtained

• Final position of the catheter within PA must be such that PCOP tracing is obtained whenever 75-100% of 1.5ml maximum volume of balloon is insufflated– If < 1ml of air is injected and PAOP is seen then it is

overwedged needs to be withdrawn

– If after maximal inflation fails to result in PCOP tracing or after 2-3 seconds delay too proximal – advanced with balloon inflated

• PCWP/PAOP interprets Left atrial pressures

more importantly – LVEDP

– Best measured in • Supine position • At end of expiration • Zone 3 (most dependent region)

– Normal PCWP- 6-15 mmHg ; Mean :9mmHg

• Abnormal PAOP:– Increased LVEDP Increased PAOP• LV systolic HF• LV Distolic HF• Mitral and Aortic valve disease• Hypertrophic cardiomyopathy• Hypervolemia• Large R-L shunts• Pericardial disease

• Decreased PCWP:– Hypovolemia– Obstructive shock due to large pulmonary embolus

• Abnormal waveforms– Large a waves:

• MS• LV systolic /diastolic function• LV volume overload • MI

– Large v waves - MR

• Calculation of cardiac output:– 2 methods• Thermodilution method• Fick’s Method

– Better measurement with Cardiac index • Normal – 2.8- 4.2 l/min/m2

• Decreased CO:

– Systolic HF– Diastolic HF– MR– Hypovolemia– Pulmonary HT– RVF

• Increased CO:

– Systemic A-V fistulas– Anemia– Beriberi– Renal Disease– Sepsis

• Other uses of pulmonary artery catheter:– Detection of Left to right shunts– Estimation of systemic and pulmonary vascular

resistance

Complications

• General:– Immediate:

• Bleeding• Arterial Puncture• Air embolism• Thoracic duct injury ( L side)• Pneumothorax/hemothorax

– Delayed:• Infections• Thrombosis

• Related to insertion of PAC:– Arrhythmias (most common- Ventricular/ RBBB)– Misplacement– Knotting– Myocardial/valve/vessel rupture

• Related to maintenance and use of PAC:– Pulmonary artery perforation– Thromboembolism– Infection

Thank You