Monitoring in cardiac ananesthesia
Download as PPTX, PDF16 likes3,777 views
The document discusses pulmonary artery catheters, including their history, components, uses, and complications. Key points include: - Pulmonary artery catheters were developed in the 1970s and allow monitoring of right atrial, right ventricular, pulmonary artery, and pulmonary capillary wedge pressures. - The catheter has multiple lumens to monitor pressures and temperatures and inflate a balloon to measure pulmonary capillary wedge pressure. - Indications include high-risk surgery patients and those with heart or lung diseases to guide fluid management. - Waveforms provide information on heart pressures and volumes that can indicate conditions like pulmonary embolism or heart failure. - Potential complications include infection, arrhythmias, and pulmonary damage
Monitoring in cardiac ananesthesia
- 1. Monitoring in Cardiac Anaesthesia: PCWP Dr Abhishek Rathore Moderator : Col Ramprasad
- 2. • History • Pulmonary Artery Catheter • Insertion of PAC • Indications • Waveforms • Complications • Pitfalls
- 3. History • Lewis Daxter (1945): first pulmonary aretry catherization • Swan, Ganz and colleagues (1970): Flow directed PA catheter • Hemodynamic assessment of patients with acute MI.
- 4. Pulmonary artery catheterization • Site: – Any central vein – Rt IJV most preferred – For other sites extra distance required • Lt IJV/ Rt & Lt EJV : 5-10 cm • Femoral veins : 15cm • Antecubital veins : 30-35 cms
- 5. Pulmonary Artery Catheter PA Distal Proximal Injectate RA infusion port Thermistor port Balloon inflation port The standard catheter is 7.5 FR and 110 cm long. Maximal balloon volume 1.5cc
- 6. Pulmonary Artery Catheter • 7.0 to 9.0 Fr • 110 cm length • 10 cm marking • 4 internal lumens • Distal port used for PAP • 2nd lumen: CVP monitoring • 3rd lumen : balloon near the tip • 4th lumen: houses wires for temperature thermistor
- 7. Equipment • Informed consent • 7.5 Fr pulmonary artery catheter (PAC) • 8.5 Fr introducer set with “side-port” • Central line insertion tray and central line dressing kit with sterile dressing • Flush solution, pressure bag, disposable pressure tubing with transducer • Transducer holder
- 8. Quality Control Issues for PA Catheters • “Zero” system at setup • Do square flush wave test, after zeroing, obtaining blood samples, with tubing changes, or if waveform distorted. • Prime tubing and stopcocks by gravity. • Maintain continuous flush system. • Use standard (universal) precautions, aseptic technique • Measure all values at end-expiration .
- 9. Referencing the “zeroing” stopcock to Phlebostatic Axis The phlebostatic axis is the approximate level of the left atrium. It is located midway between the anterior-posterior chest wall at the 4th intercostal space. The patient need not be flat, but must be supine.
- 10. Inserting a PAC
- 11. Indications • Surgical patients associated with high risk of complications from hemodynamic changes • Advance cardiopulmonary diseases • Goal directed fluid therapy
- 13. Waveforms identified by movement of the catheter through the right side of the heart into the pulmonary artery and capillary bed: Right atrial (RA) Right ventricular (RV) Pulmonary artery pressure (PAP) Pulmonary capillary wedge pressure (PCWP) or Pulmonary artery wedge pressure (PAWP)
- 14. a wave follows “P” wave on ECG v wave follows the QRS complex on ECG RAP = mean (average) of a wave Right atrial pressure (RAP) is measured by the distal tip of the PAC on insertion or by the proximal port post insertion. The waveform has two primary characteristics: “a” wave and “v” wave. a = atrial systole v = ventricular systole Right Atrium Tricuspid valve Pulmonic valve P QRS
- 15. Measurement of Right Atrial Pressure (RA) from Pulmonary Artery Catheter Normal RAP = 2 – 6 mmHg The “a” wave represents atrial contraction and estimates atrial filling at end-diastole. Locate the “a” wave by alignment with the PR interval on ECG. Measure the mean (average) of the height of the “a” wave and the bottom of the “a’ wave at end-expiration.
- 16. RA Waveform “c” wave = closure of the tricuspid valve “x” decent = follows closure of the tricuspid valve, “y” decent = follows closure of the pulmonic valve
- 17. Alterations in RA Pressure • Reflects filling volume of the right atrium • Low pressure consistent with hypovolemia: – Trauma-> blood loss – Dehydration – Loss of fluid from drains – Vomiting, diarrhea – Burns – 3rd spacing of fluid • Consistent with tachycardia, ↓ urine output, dry skin & mucous membranes
- 18. Clinical Situations Consistent with Elevations in RA Pressures • Tricuspid stenosis, regurgitation • RV ischemia or failure • Pulmonary hypertension • Pulmonic stenosis • Pulmonary embolism • Atrial ventricular dissociation with loss of synchrony – Atrial arrythmias, A-V conduction blocks)
- 19. Systolic pressure Diastolic pressure Onset of systole follows QRS complex on ECG End diastole occurs at the onset of systole. Right ventricular pressure (RVP) is measured from the distal tip of PAC on insertion or from the RV port (gray) post insertion. RVP has a systolic and diastolic component. QRS Right ventricle
- 21. Alterations in RVP Reflects filling volume of right ventricle Normal RV = 25-30/0-5 mmHg • Low pressure consistent with low volume – Usually accompanies low RAP • Elevation associated with: – Hypervolemia – Pulmonary embolism – Outflow obstruction – RV infarct/failure – Pericarditis/tamponade – LV failure – Primary and secondary pulmonary hypertension (PHTN) – Pulmonic stenosis – COPD
- 22. Pulmonary artery pressure (PAP) is measured from the distal tip of PAC on insertion and distal tip post insertion. It has a systolic and diastolic component. PA systolic PA diastolic Dicrotic notch Represents closure of the pulmonic valve Systolic pressure follows QRS on ECG. Diastole begins at the closure of the pulmonic valve and continues to next onset of systole. Pulmonic valve QRS
- 23. Alterations in PAP Represents filling volume in the pulmonary artery and resistance to flow within the pulmonary circuit Normal PAP = 20-30/8-15 mmHg • Low pressure consistent with hypovolemia – Consistent with ↓ RAP and ↓ RVP • High pressure consistent with – PHTN – COPD – Acute respiratory distress syndrome (ARDS) – Pulmonary embolism (PE) – Mitral stenosis – Left ventricular heart failure
- 24. PAP Waveform
- 25. Pulmonary capillary wedge pressure (PCWP) or pulmonary artery wedge pressure (PAWP) is measured from the distal port of PAC with balloon inflated. The PCWP represents left atrial filling pressure reflected through the pulmonary circuit. Normal value 8-14 mmHg. PCWP = mean (average) of “a” wave a = atrial systole v = ventricular systole
- 26. Catheter tip looks “through” the pulmonary circulation to “see” the left atrial pressure. PCWP indirectly measures left atrial pressure
- 27. Measurement of PCWP from Balloon Port • Inflate balloon with only as much air as needed to create a change in the waveform (no more than 1.5cc air). • Observe for change in waveform. • Locate the “a” wave on the PCWP waveform. – Use the QRS as a marker to detect the “a” waveform. • Measure the mean of the “a” wave to obtain the PCWP • PA diastolic (PAD) should correlate to the PCWP and be 0-5 mmHg greater. (PAD ≥ PCWP) • High levels of positive end expiration pressure (PEEP) will raise the PCWP.
- 28. Alterations of PCWP • Low pressure consistent with hypovolemia • Elevations consistent with: – Mitral stenosis/regurgitation – Aortic stenosis/regurgitation – Acute LV ischemia/infarct – LV failure – Atrial ventricular dissociation with loss of synchrony • Both RA and PCWP elevated in cardiac tamponade, constrictive pericarditis, and hypervolemia
- 29. Once inserted balloon should remain DEFLATED and ONLY reinflated for periodic measurement of PCWP. PAP waveform should be displayed at all other times. Distal tip (Yellow) Proximal tip (Blue) Right ventricular Port (Gray) Distal tip measures PAP and PCWP Proximal tip measures RA and is site for CO measurement and fluid administration Right ventricular port site for fluid administration RA infusion port (white)
- 30. Complications of PA Catheters – Air embolism – Infection – Atrial & ventricular arrhythmias – Hemoptysis ( caused by excessive expansion of the balloon in the wedge position) – Areas of infarction – Thrombus formation /PE – Local endothelial damage – Pulmonary rupture – Thrombophlebitis – Pneumothorax
- 31. Summary of Pulmonary Artery Pressure Waveforms Normal 2-6 mmHg Normal 20-30/0-5 Normal 20-30/8-14 Normal 8-14 mmHg mmHg mmHg
- 32. Pitfalls • Data provided by PAC may not be accurate • Risks for PAC itself • Harm due to knowledge deficiet • Data may not be useful in managing critically ill patients • May result in overtreatment (
- 34. Thank you
- 35. Phlebostatic axis • Reference levels for various body positions. A, Supine/prone. The reference point is the phlebostatic axis, which is the intersection of 2 reference lines: first, an imaginary line from the fourth intercostal space at the point where the space joins the sternum, drawn out to the side of the body; second, a line drawn midway between the anterior and posterior surfaces of the chest. B, Supine with the head of the bed elevated. The phlebostatic level is a horizontal line through the phlebostatic axis. Measurements of pulmonary artery pressure and central venous pressure can be obtained at backrest elevations of up to 60°. C, 30° lateral position. The reference point is one-half the distance from the left sternal border to the surface of the bed. (Based on data from VanEtta et al.6) D, 90° lateral position. In the 90° right lateral position, the reference point is the intersection of the fourth intercostal space at the midsternum. In the 90° left lateral position, the reference point is the intersection of the fourth intercostal space at the left parasternal border.