Guided Lecture Notes, Chapter 9, Hemodynamic Monitoring

Guided Lecture Notes, Chapter 9, Hemodynamic Monitoring

Guided Lecture Notes, Chapter 9, Hemodynamic Monitoring

Learning Objective 1 Describe the type of information provided by, and common indications for, hemodynamic monitoring.

  • Review indications. (Refer to PowerPoint Slide 2.)
  • Explain hemodynamic monitoring provides information at the bedside about intracardiac and intravascular pressures, and cardiac output. It is used in critical care settings.

Learning Objective 2 State the basic components of a pressure monitoring system and describe nursing interventions that ensure accuracy of pressure readings and waveforms.

  • Review the components of the system. (Refer to PowerPoint Slide 2.)
  • Explain that a pressure monitoring system transmits pressures from the cardiac chambers and intravascular space through a fluid-filled noncompliant pressure tubing to a transducer that converts this into an electrical signal, giving a digital value.
  • The Square-Wave Test. Explain that the square-wave test ensures accuracy of the system by evaluating dynamic response. To test, the nurse flushes the device and rapidly releases while observing the bedside monitor for changes in the waveform. (Refer to PowerPoint Slide 4.)
  • Square-Wave Test. (Refer to PowerPoint Slide 4.)
  • Explain that overdamped systems may be caused by system leaks, blood clots, long tubing or large air bubbles in the tubing or transducer, produce erroneously low systolic pressures and, occasionally, erroneously low diastolic pressures.
  • Explain that underdamped systems may be caused by small air bubbles in the system or very rigid pressure tubing can produce erroneously high systolic pressures and erroneously low diastolic pressures.
  • Leveling and Zeroing. (Refer to PowerPoint Slide 5.)
  • Explain that the system must be leveled to an external landmark and zeroed to atmospheric pressure.
  • The external landmark is the phlebostatic axis—fourth intercostals space, midaxillary line. The site should be marked to ensure consistent leveling.
  • The nurse uses a carpenter or laser light level to align the phlebostatic axis with the air–fluid interface (the stopcock nearest the transducer).
  • If the transducer is above the phlebostatic axis, there may be false low readings.
  • If the transducer is below the phlebostatic axis, there may be false high readings.

Learning Objective 3. Describe nursing interventions associated with arterial pressure monitoring.

  • Discuss alarm settings and parameters.
  • Discuss the importance of visualizing the site at all times.

Learning Objective 4. Interpret data obtained through arterial pressure monitoring.

  • Describe waveform. (Refer to PowerPoint Slide 10.)
  • Upstroke is rapid ejection of blood from the left ventricle into the aorta.
  • Dicrotic notch is closure of the aortic valve and the beginning of diastole.
  • End point is the end of diastole.
  • The value measured at the peak is systolic pressure and the value at the lowest point of the waveform is diastolic pressure.
  • MAP evaluates perfusion of organs normal being 70 to 105 mmHg.
  • Discuss complications.

Learning Objective 5. Describe nursing interventions associated with central venous pressure monitoring.

  • Monitor for complications such as infection, thrombosis, pneumothorax, and air embolism.
  • Sterile dressing change per organization protocol and CDC recommendations.

Learning Objective 6. Interpret data obtained through central venous pressure monitoring.

  • Explain that the CVP measurement is associated with alterations in intravascular volume status and can be used in conjunction with clinical data such as breath sounds, heart and respiratory rate, JVD, and urine output.

Learning Objective 7. Describe nursing interventions associated with pulmonary artery pressure monitoring.

  • Describe the lumens.
  • Distal—opens into the pulmonary artery. Measures mixed venous O2 saturation. Not recommended for fluid administration.
  • Proximal lumen—opens into the right atrium. Obtain right atrial pressure measurements. May infuse fluids and inject solution for cardiac output measurement through this lumen.
  • Thermistor—measures the patient’s core temperature
  • Balloon inflation–when inflated causes pulmonary artery occlusion and provides a pulmonary artery wedge pressure

Learning Objective 8. Interpret data obtained through pulmonary artery pressure monitoring.

  • Define the various pressures obtained from the pulmonary catheter. (Refer to Table 9-2.)
  • Discuss normal values and causes of variances as described in Table 9-2.

Learning Objective 9. Describe methods commonly used in the critical care setting to determine cardiac output.

  • Define normal values and parameters. (Refer to PowerPoint Slides 20 and 21.)
  • Explain that stroke volume is influenced by the following, refer to Figure 9-12 for factors that increase or decrease cardiac output:
  • Preload
  • Afterload
  • Contractility
  • Describe the methods for obtaining CO. Explain that thermodilution is the gold standard and is most widely used.

Learning Objective 10. List factors that affect oxygen demand and oxygen delivery, and describe methods used to evaluate the balance of oxygen supply, oxygen consumption, and oxygen demand.

  • Explain the concept of oxygen supply versus oxygen demand.
  • Explain that oxygen consumption is determined by oxygen demand, oxygen delivery, and oxygen extraction.
  • Discuss lab measurements that evaluate oxygen delivery.
  • Lactate
  • pH
  • Base excess/base deficit
  • Mixed venous saturation
  • Discuss methods for measuring oxygenation status regionally. (Refer to PowerPoint Slide 43.)
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