Hemodynamics Study Guide PDF

# Hemodynamics Study Guide ## Key Concepts - **Cardiac Output (CO):** Amount of blood pumped by each ventricle in one minute. - **Formula:** CO = Stroke Volume (SV) x Heart Rate (HR) - **Normal Range:** 4 - 8 L/min - **Cardiac Index (CI):** CO divided by body surface area (BSA). - **Normal Range:*...

# Hemodynamics Study Guide ## Key Concepts - **Cardiac Output (CO):** Amount of blood pumped by each ventricle in one minute. - **Formula:** CO = Stroke Volume (SV) x Heart Rate (HR) - **Normal Range:** 4 - 8 L/min - **Cardiac Index (CI):** CO divided by body surface area (BSA). - **Normal Range:** 2.2 - 4 L/min/m² - **Preload:** Volume in the ventricle at the end of diastole. - Reflects fluid volume status - **Afterload:** Resistance the left ventricle must overcome to pump blood. - **High Afterload:** Increased workload for the heart. - **Low Afterload:** Decreased resistance. - **Contractility:** Strength of ventricular contraction. ## Hemodynamic Parameters 1. **PAWP:** Reflects left atrial pressure. - **Normal:** 6 - 12 mmHg 2. **RAP or CVP:** Reflects right atrial pressure and fluid volume. - **Normal:** 2 - 8 mmHg 3. **MAP:** Average arterial pressure during one cardiac cycle. - **Normal:** 70 - 100 mmHg - **Formula:** MAP = SBP + 2(DBP)/3 4. **CI:** CO adjusted for BSA. - **Normal:** 2.2 - 4 L/min/m² 5. **CO:** Volume of blood pumped per minute. - **Normal:** 4 - 8 L/min 6. **PAP:** - **Pulmonary Artery Pressure= PAS (Systolic):** 20 - 30 mmHg - **PAD (Diastolic):** 8 - 12 mmHg - **PAM:** ~25 mmHg - **Increased PAWP:** Indicates fluid overload. - **Decreased PAWP:** Suggests hypovolemia. - **Increased CVP:** Indicates fluid volume excess. - **Decreased CVP:** Suggests fluid deficit. ## Hemodynamic Monitoring - Measures pressure, flow, and oxygenation in the cardiovascular system. - Goal: Assess heart function, fluid balance, and effects of drugs on CO. - **Parameters Measured:** - **Pulmonary Artery Wedge Pressure (PAWP):** Reflects left atrial pressure (via Swan-Ganz catheter). - **Central Venous Pressure (CVP):** Reflects right ventricular preload (via triple-lumen catheter or PA catheter). - **Pulmonary Arterial Pressures (PA):** Monitored using Swan-Ganz catheter - **CO/CI:** Assesses cardiac output and function. ## Pulmonary Artery Catheter (Swan-Ganz) - **Purpose:** Inserted into a central vein and floated into the pulmonary artery to measure: - **Pulmonary Artery Pressures (PAS, PAD).** - **PAWP:** Indirect measure of left atrial pressure - **CVP:** Right atrial pressure. - **CO and CI** - **Key Features:** 1. **Balloon Tip:** - Inflate Max of 1.5 mL for Max 15 sec to measure PAWP. - Overinflation of balloon (Wedging) can cause rupture of PA. 2. **Lumens:** - **2 Proximal Lumen:** Measures CVP; used for fluids, meds, or blood draws. - **Distal Lumen:** Measures PAS, PAD, and PAM. - **Temp sensor near distal tip** 3. **Markings:** - Thin lines = 10 cm, thick lines = 50 cm - Helps monitor catheter placement. ## Principles of Invasive Pressure Monitoring & Phlebostatic Axis - **Purpose:** Ensures accurate pressure readings during hemodynamic monitoring. - **Key Points:** 1. **Equipment Setup:** - Must be referenced and zero-balanced to the environment. - Optimize dynamic response characteristics for precise readings. 2. **Referencing**: PT in supine position - Align transducer to the phlebostatic axis: - Intersection of midaxillary line (between anterior and posterior) and through 4th intercostal space - Represents the level of the atria when the patient is supine. 3. **Zeroing:** - Confirms that when pressure w/in system is zero, the monitor reads zero. - **How:** Open reference stopcock to air (off to patient). - Perform during initial setup and periodically thereafter. - **Goal:** Maintain proper equipment alignment and calibration for reliable measurements. ## Pulmonary Artery (PA) Monitoring - **Purpose:** Guides management of cardiopulmonary conditions by providing detailed measurements of heart function and fluid volume. - **Key Details:** 1. **PA Pressure Tracing:** - Before balloon inflation, the waveform resembles arterial tracing: - Features a systolic peak, dicrotic notch, and diastolic low point. - As the balloon inflates and “wedges,” the waveform changes shape and amplitude. 2. **Measurements:** - **PAWP:** Inflated balloon measures left atrial pressure - **PAS/PAD:** Indicate pulmonary artery pressures. - PAWP and PAD are sensitive indicators of heart function and fluid volume status - Allows precise manipulation of preload - **Specialized Features:** - Atrial electrode, Fiberoptic sensor for mixed venous O2 saturation. - Continuous: right ventricular volume, EF, and CO monitoring data w/ additional ports for IV access ## Pulmonary Artery Waveforms - **Waveform Stages During Insertion:** 1. **Right Atrium (RA):** Low pressure with smooth waves. 2. **Right Ventricle (RV):** - Recorded only during insertion; note for the cardiologist. - Sharp peaks with increased systolic pressure. 3. **Pulmonary Artery (PA):** Clear systolic/diastolic pressures with a dicrotic notch. 4. **PAWP (Wedge Pressure):** Flattened waveform during balloon inflation. ## Complications of Pulmonary Artery Catheter 1. **Infection and Sepsis:** - Use aseptic technique during insertion & maintenance - Change tubing, flush bag, stopcock and transducer every 96 hours. 2. **Air Emboli (e.g Disconnection):** - Monitor Ballon integrity - Luer-lok connections and alarms on 3. **Pulmonary Artery Rupture/Infarction:** - Avoid overinflating the balloon, Do not exceed 1.5 mL during inflation. - Over wedging can rupture the pulmonary artery due to excessive pressure. - Monitor waveforms continuously - Maintain continuous flush system 4. **Ventricular Dysrhythmias:** - Monitor ECG during catheter insertion, removal, or migration of PA catheter. ## Central Venous Pressure (CVP) Monitoring - Measurement of right ventricular preload that reflects fluid volume - Obtained from: - Central venous catheter - PA catheter - Similar to PAWP waveforms ## Measuring Cardiac Output - Continuous Cardiac Output (CCO) - PA catheter with thermal filament located in right atrium - Senses change in temperature of blood as it passes through right ventricle - Measures every 30 to 60 seconds - Reflects average CO for past 3 to 6 minutes ## What Do the Values Mean? - PA, CVP, and PAWP measure heart function and fluid balance - PA pressures = pressure in the pulmonary artery - CVP = measurement of vena cava or right atrium; reflects fluid volume status - PAWP = measures Left atrial pressure - To sum it up.... These numbers are really evaluating preload, which is a volume issue ## A-Line Monitoring - **Purpose:** Provides continuous BP monitoring - **Placement:** - Radial artery is commonly used. - Sutured in place, then immobilize arm (w/ board) to secure. Don't want movement - Perform an Allen test to assess collateral circulation before insertion. - **Used For:** - PTs on vasopressors, FQ ABG sampling, Shock, acute hemodynamic instability, acute hypotension, PT needs continuous monitoring of BP - **Note:** NEVER GIVE IV FLUIDS THROUGH ART LINE ## A-Line Waveforms - Correspond to ECG rhythm, QRS corresponding to atrial wave form - **Dicrotic Notch:** Indicates valve closure. - **Square Wave Test:** Confirms proper zeroing and flushing of the A-line system. ## Nursing Interventions with A-Line 1. **Hemorrhage Prevention:** - Ensure Tight Luer-Lok connections including tubing. - Activate monitor alarms. - Check arterial waveform (look for a good dicrotic notch). 2. **Infection Monitoring:** - Monitor for local signs of inflammation. - Change pressure tubing, flush bag, and transducer every 96 hours. 3. **Circulation Monitoring:** - Perform Allen test before insertion: - **Positive Allen Test:** Pinkness doesn't return in 6-7 seconds. - Hourly checks for circulation (look for paralysis, pain, paresthesia). Emergency if impaired 4. **Ensure Correct Waveform and A-Line BP Correlation:** - Ensure A-line BP matches ECG waveform. 5. **Leveling and Zeroing:** - Calibrate the A-line system. 6. **Removing A-Line:** - Remove sutures first. - Hold pressure for 5 minutes (radial) or 10 minutes (femoral). - Monitor closely for bleeding. ## Noninvasive Hemodynamic Monitoring - Uses external sensor pads placed around heart to measure cardiac output (CO) and cardiac index (CI) - **Advantages:** Less invasive than Swan-Ganz Catheter # Cardiogenic Shock Overview ## Definitions - **Cardiogenic Shock:** - A syndrome characterized by decreased tissue perfusion and impaired cellular metabolism due to an imbalance in oxygen/nutrient supply and demand. - **Pathophysiology:** - **Systolic Dysfunction:** Heart cannot pump blood forward (↓ stroke volume and cardiac output < 4 L/min). - **Diastolic Dysfunction:** Heart cannot fill properly (↓filling → ↓ stroke volume). - Results in severe pump failure, vasoconstriction, and increased central venous pressure (CVP) and pulmonary artery wedge pressure (PAWP). ## Causes - **Systolic Dysfunction:** - Myocardial infarction (most common) - Cardiomyopathy, blunt cardiac injury - Severe systemic or pulmonary hypertension - Myocardial depression from metabolic issues. - **Result:** Impaired contractility, thin/weak heart muscle, low ejection fraction (<50%). - **Diastolic Dysfunction:** - Cardiac tamponade (requires pericardiocentesis) - Ventricular hypertrophy, cardiomyopathy - Structural issues: valvular stenosis/regurgitation, tension pneumothorax, ventricular septal rupture. - **Result:** Impaired filling/ relaxation, Thick/stiff heart muscle, normal ejection fraction. ## Clinical Manifestations - **Early Signs:** - Tachycardia, hypotension, narrow pulse pressure - Increased myocardial oxygen Consumption - Angina, fatigue, a sense of impending doom - Signs of hemodynamic instability - **Physical Findings:** - Cool, clammy skin, pallor, delayed capillary refill - Pulmonary congestion (crackles), tachypnea - Anxiety, confusion, agitation - Decreased urine output ## Complications - **Cardiac Arrest:** - Due to organ hypoperfusion and myocardial workload. - **Causes:** - Persistent myocardial ischemia or ventricular dysrhythmias. - **Associated Diagnoses:** - Acute coronary syndromes, ventricular rupture, pulmonary embolism. ## Diagnostics - **Lab Tests:** - Troponin, BNP, CPK-MB, BMP, CBC, lactic acid - **Imaging:** - **Echocardiogram:** Assess ejection fraction. - **12-lead ECG:** Identify ischemia, infarction, or dysrhythmias - **Chest X-ray:** Detect pulmonary congestion or structural issues. ## Nursing Assessments - **Neurological:** - Monitor for decrease or changes in LOC, anxiety, restlessness. - **Respiratory:** - Assess oxygen saturation, work of breathing, crackles on auscultation. - **Cardiac:** - Chest pain, Temp, HR, Continuous ECG & 12 lead, BP, CVP, PA pressures, C/O - Monitor for dysrhythmias, murmurs (S3, S4 gallops), chest pain. - **Renal:** - Monitor urine output hourly (report <30 mL/hr for 2 hours). - Assess edema, BUN, creatinine, and electrolytes. - **Gastrointestinal:** - Monitor NGT, bowel sounds, abdominal distention, and for ischemic bowel symptoms. ## Nursing Care - **Respiratory:** - Provide oxygen therapy, BiPAP (decreases Pre/afterload), or mechanical ventilation. - Administer diuretics to reduce preload and pulmonary edema - **Cardiac:** - Continuous ECG monitoring, hemodynamic profiles - Vital signs every 15 minutes. - Prevent DVTs; manage assistive devices and IV gtts - **Gastrointestinal:** - Diet consult, small bore feeding tube, Initiate low/slow enteral feeding within first 24 hours. - Prevent ulcers with PPIs; use stool softeners if needed for bowl regiment - **Renal:** - Monitor fluid retention and manage edema. - hemodialysis or Consider CRRT for unstable patients needing blood purification. ## Nursing Focus - **Decrease Workload:** - **Nitrates (e.g., Nitroglycerin):** Dilate coronary arteries. - **Considerations:** Glass bottle, Avoid with erectile dysfunction drugs (Avanafil, sildenafil, tadalafil, varde) causes severe hypotension, monitor for hypotension, dizziness, headache, syncope - **Reduce Preload:** - **Diuretics (e.g., Furosemide- IVPB, Bumetanide-IBPB/gtt):** Decrease pulmonary congestion. - **Considerations:** Monitor potassium, risk of ototoxicity. - **Reduce Afterload:** - **Vasodilators (e.g., Nitroprusside):** Lower systemic vascular resistance. - **Considerations:** Risk of: cyanide toxicity (after 36 hours), headache, dizziness, increased ICP, brady/ tachycardia, hypotension, palpitations; Administer: very small doses (very potent), protect from light. - **Increase Contractility:** - **Inotropes (e.g., Dopamine, Epi, Dobutamine, Milrinone):** Improve cardiac output. - **Considerations:** Dobutamine- initial hypotension then increases BP, Monitor CO/CI, ONLY use deep line for administration. ## Interprofessional Care - **Overall Goal:** - Restore myocardial blood flow by restoring Balance oxygen supply and demand. - **Key Procedures:** - Angioplasty with stenting (percutaneous transluminal coronary angioplasty (PTCA) - Valve replacement - Emergency revascularization & Prevent cardiac arrest - **Drug Therapy:** - Nitrates (dilate coronary artery), diuretics (reduce preload), vasodilators (decrease afterload, achieve/maintain MAP >65), B-adrenergic blockers (decrease HR) - **Circulatory Assistive Devices:** Decrease SVR and left ventricular workload - IABP: Decreases systemic vascular resistance and myocardial workload. - VAD: Supports ventricular function. - Heart transplantation: For end-stage failure. ## Heart Catheterization: Percutaneous coronary intervention (PCI) - **Purpose** - To restore oxygen supply and demand balance in cardiogenic shock. - Diagnostic and therapeutic procedure to identify and reduce blockages in coronary arteries. - **Key Timeframes: Door-to-Balloon Time Goal-** Coronary artery should be reopened within 90 minutes after patient arrival. ## Pre-Procedure Interventions 1. **IV Access:** Insert two large-bore IVs. 2. **Consent:** Obtain consent for the procedure and blood products. 3. **Medications:** - **Thrombolytics:** To dissolve clots. - **Anticoagulants (e.g., Heparin):** Prevent further clot formation (monitor PTT). - **Antiplatelets (e.g., Aspirin, Clopidogrel):** Reduce platelet aggregation. - **Pain Management (e.g., Morphine):** Relieve chest pain and anxiety. ## Nursing Considerations overall of cardiogenic shock - Maximizing oxygen delivery to tissues. - Bedrest to decrease oxygen demands. - Oxygen support & mechanical ventilation. - Maintaining an adequate H & H. - Palliative care consult.