Hemodynamic Monitoring (Invasive Lines) PDF

# Hemodynamic Monitoring ## Concepts of Hemodynamics ### Cardiac Output (CO) - Formula: CO = HR × SV - Definition: Volume of blood pumped by the heart in one minute. - Normal range: 4 - 8, L/min ### Ejection Fraction (EF) - Definition: Percentage of total blood in the ventricle at the end of di...

# Hemodynamic Monitoring ## Concepts of Hemodynamics ### Cardiac Output (CO) - Formula: CO = HR × SV - Definition: Volume of blood pumped by the heart in one minute. - Normal range: 4 - 8, L/min ### Ejection Fraction (EF) - Definition: Percentage of total blood in the ventricle at the end of diastole that is ejected from the heart with each beat. ## Preload - Definition: Degree of stretch of the cardiac muscle at the end of diastole. - Occurs when the volume in the ventricles is highest. ### Factors Affecting Preload: - Amount of blood in the ventricle (venous return). - Compliance/Extensibility of the ventricle. ### Measurement: - Known as filling pressure, expressed in mmHg. - Normal Central Venous Pressure (CVP): 2 - 6, mmHg. - Used to estimate fluid volume. ### Starling's Law - Part 1: Greater stretch of the heart muscle at the end of diastole leads to a stronger contraction. - Part 2: Excessive filling can lead to decreased cardiac output due to high left ventricular end-diastolic (LVED) volume and pressure. ## Effects of Preload - Increased preload results in: - Increased stroke volume. - Increased cardiac output. - Increased myocardial oxygen demand. - Decreased preload results from: - Dehydration. - Blood loss. - Sepsis. ## Afterload - Definition: Pressure or resistance the ventricle must overcome to eject blood. ### Forces Affecting Afterload: - Systemic and pulmonary arterial pressures. - Systemic vascular resistance (SVR). - Resistance from aortic and pulmonic valves. - Diameter of blood vessels. - Blood viscosity. ## Summary of Hemodynamics - Preload: Volume. - Afterload: Resistance. ## Purpose of Hemodynamics - Measurement of pressure, volume, and oxygenation of blood within the cardiovascular system. - Involves connecting a patient to a transducer via an invasive catheter (e.g., central IV line, arterial line). ## Types of Invasive Lines 1. **Arterial Line** - Used for continuous blood pressure monitoring and blood draws. 2. **Central Venous Catheter (CVC)** - Measures right atrial pressure (CVP). - Normal CVP: 2 - 6, mmHg. 3. **Pulmonary Artery Catheter (Swan-Ganz)** - Measures left atrial pressure (PAWP). - Normal PAWP: 6 - 12, mmHg. ## Monitoring and Calibration - **Transducer:** Converts physiological events into electrical signals. - **Zeroing:** Necessary to ensure accurate readings. - Must be done at least every 8 hours or with position changes. - **Phlebostatic Axis:** Level of the right atrium, located at the 4th intercostal space at the midaxillary line. ## Arterial Line Monitoring - **Mean Arterial Pressure (MAP):** - Formula: MAP = (SBP + (DBP × 2)) / 3 - Normal range: 70 - 105, mmHg. - Minimum MAP of 60, mmHg is needed to perfuse vital organs. ## Complications and Interventions - **Complications:** - Limb impairment. - Infection. - Thrombosis/arterial occlusion. - **Interventions:** - Monitor for perfusion (capillary refill, numbness). - Apply pressure if the line is dislodged. ## Central Venous Pressure (CVP) - **Indications:** Monitor fluid status, guide therapy. - **Nursing Interventions:** - Maintain dressing changes. - Confirm initial placement with chest X-ray. - Monitor trends in CVP readings. ## Pulmonary Artery Catheter - **Purpose:** Reflects pressure of the left atrium and left ventricular preload. - **Placement:** Confirmed with chest X-ray; balloon must be deflated after placement. - **Measurements:** - Low PAWP: Indicates conditions like MI, heart failure. - High PAWP: Indicates conditions like sepsis, hyperthyroidism. These notes summarize the key concepts of hemodynamic monitoring, focusing on preload, afterload, and the purpose of various invasive lines used in clinical settings.