Megan McClintock, MS, RN

1. Critical Care (Cardiac) Megan McClintock, MS, RN Winter 2012

2. CCUs or ICUs • RRTs – rapid response teams • Pts exhibit subtle changes 6-8 hrs before a cardiac and/or respiratory arrest • Critical care nurse, RT, MD or APN • PCUs • Transition between ICU and general care • Critically ill patient • Physiologically unstable • At risk for serious complications • Requires intensive and complicated nursing support

3. Common Problems of ICU Patients • Venous thromboembolismd/t immobility • Skin problems d/t immobility • Nutritional deficiencies d/thypermetabolic or catabolic states • Start enteral or parenteral nutrition early • Anxiety d/t threat to physical health, foreign environment, pain, sleeplessness, immobilization, loss of control, impaired communication • Work closely with pts, families, caregivers • Encourage caregivers to bring in personal items and photographs • Judiciously use antianxiety drugs (ie. Ativan) • Judiciously use massage, guided imagery

4. Common Problems of ICU Patients • Pain d/t medical conditions, immobilization, invasive monitoring devices and procedures • Continuous IV sedation (ie. Propofal [Diprivan]) and an analgesic (ie. Fentanyl [Sublimaze]) but include a daily “sedation vacation” • Impaired Communication d/t use of sedative or paralyzing drugs, ET tube • Always explain what is happening to the patient • Use picture boards, notepads, computer keyboards • Look directly at the patient • Use hand gestures when appropriate • Use an interpreter with non-English speaking patients • Provide comforting touch

5. Common Problems of ICU Patients • Sensory-Perceptual Problems d/t delirium • Assess for delirium with the Confusion Assessment Method for ICU and the Intensive Care Delirium Screening Checklist • Address physiologic factors • Use clocks and calendars to help orient the pt • Encourage presence of a caregiver • May need haloperidol (Haldol) • Sensory-Perceptual Problems d/t sensory overload • Be cautious with conversations • Mute phones • Set alarms appropriate to the pt’s condition • Limit overhead paging • Limit any unnecessary noise

6. Common Problems of ICU Patients • Sleep Problems d/t noise, anxiety, pain, frequent monitoring, treatment procedures • Structure the environment to promote the sleep-wake cycle • Cluster activities • Schedule rest periods • Dim lights at nighttime, open curtains during daytime • Limit noise • Provide comfort measures (ie. Back rubs) • Use benzodiazepines (ie. Temazepam [Restoril]) or zolpidem (Ambien)

7. Caregivers • Give them guidance and support • Actively listen • Provide them with opportunity to participate in decision making • Involve durable power of attorney for health care if pt is incapable of making decisions • Give convenient access to the pt • Prepare caregivers for the ICU and the pt’s appearance • Provide for the option of family presence during invasive procedures and CPR • Be culturally aware especially in regards to death and dying

8. Hemodynamic Monitoring • Measurement of pressure, flow, and oxygenation within the cardiovascular system • Invasive (internally placed) • Noninvasive (externally placed) • Includes: • Systemic and pulmonary arterial pressures • CVP – central venous pressure • PAWP – pulmonary artery wedge pressure • CO/CI – cardiac output/cardiac index • SV/SVI – stroke volume/stroke volume index • Oxygen saturation • Integrating and trending all of this data together provides a picture of the pt’s hemodynamic status • Very important to be technically accurate to prevent unnecessary or inappropriate treatment

9. Hemodynamic Terminology • Cardiac Output (CO) and Cardiac Index (CI) • Volume of blood (in liters) pumped by the heart in 1 minute, cardiac index is adjusted for BSA and is a more precise measure of efficiency of the pumping action of the heart • Increased with high circulating volume • Decreased with low circulating volume or decrease in strength of ventricular contraction • CO normal 4-8, CI normal 2.5-4 • Stroke Volume (SV) and Stroke Volume Index (SVI) • Volume of blood (in mL) ejected with each heartbeat, determined by preload, afterload and contractility, SVI is adjusted for BSA • Increased with volume overload, inotropy, hyperthermia, meds (ie. Digitalis, dopamine, dobutamine) • Decreased with impaired cardiac contractility, valve dysfunction, CHF, beta blockers, MI • SV normal 50-100, SVI normal 25-45

10. Hemodynamic Terminology • Systemic Vascular Resistance (SVR) • Opposition encountered by left ventricle • Increased with vasoconstrictors, low volume • Decreased with vasodilators, morphine, nitrates, high CO2 • Pulmonary Vascular Resistance (PVR) • Opposition encountered by right ventricle • Increased with pulmonary hypertension, hypoxia • Decreased with meds (ie calcium channel blockers, aminophylline, isoproterenol, oxygen) • Preload, afterload, and contractility determine SV which then determines CO and BP

11. Hemodynamic Terminology • Preload • Volume in the ventricle at the end of diastole • Combination of pulmonary blood filling the atria and stretching • Regulated by variability in intravascular volume • PAWP will show us left ventricular preload (AKA left ventricular end-diastolic pressure) • CVP will show us right ventricular preload (AKA right ventricular end-diastolic pressure) • Increased with fluid administration • Decreased with diuretics and vasodilation

12. Hemodynamic Terminology • Afterload • Forces opposing ventricular ejection including systemic arterial pressure, resistance from the aortic valve, mass/density of the blood • Resistance the heart has to overcome to send blood to the aorta affected by vasoactivity and blood viscosity • SVR shows left ventricular afterload • PVR shows right ventricular afterload • When afterload is increased, cardiac output is decreased • To decrease afterload give vasodilators

13. Hemodynamic Terminology • Contractility • Strength of contraction • If the cardiac output changes but everything else stays the same, then the problem is with contractility • When it is increased it increases stroke volume and oxygen demand • Increased with meds (ie. Epinephrine, norepinephrine, isoproteronol, dopamine, dobutamine, digitalis) • Decreased with heart failure, alcohol, calcium channel blockers, beta blockers, acidosis • Frank Starling’s Law – the greater the preload, the greater the myocardial stretch, and the greater the oxygen need which increases CO and SV

14. Arterial Lines • Purpose - • Allen’s test • Position transducer level with the heart, then zero to negate the pressure applied by the flush • Look for a normal waveform – dicrotic notch (systolic pressure) should be after QRS on EKG • Correlate with manual BP

15. CVP Monitoring • Purpose – to tell us about the right ventricle • Placed while in Trendelberg position, CVC is threaded so that the tip rests in the superior vena cava • Can give IV fluids and draw venous blood • High point of waveform should correlate with R of ECG

16. PA Catheter • Purpose – to tell us about the left ventricle and measure CO • Often called Swan-Ganz catheter • Proximal port is for CVP and fluids • Distal port is for PA and PCWP with balloon inflation (balloon floats the catheter into a pulmonary artery branch vessel – wedge) • Thermistor – continuous temperature readings to calculate CO (inject 5-10 mL cold fluid as exhalation begins, take the average of 3 times) • Very important that the waveform has not changed or the catheter may be displaced

17. CVP or Right Atrial Pressure Normal is 2-6 • Approximates right ventricular end diastolic pressure (blood in the right atrium) • Tells us about right ventricular function and general fluid status • Increased with overhydration, increased venous return or right-sided heart failure, straining • Decreased with hypovolemia, decreased venous return

18. MAP – Mean Arterial Pressure Normal is 70-100 • Reflects changes in the relationship between CO and SVR and reflects arterial pressure in vessels perfusing the organs • Increased with increased cardiac workload • Decreased with decreased blood flow to the organs • Can make it increase by administering fluids

19. PAP – Pulmonary Artery Pressure Normal is 20-30 (systolic), 8-12 (diastolic), 25 (mean) • BP in the pulmonary artery • Increased with left to right cardiac shunt, PA hypertension, COPD, emphysema, PE, pulmonary edema, left ventricular failure

20. PCWP or PAWP – Pulmonary Capillary Wedge Pressure • Normal 4-12 • Approximates left ventricular end diastolic pressure • Increased with left ventricular failure, mitral valve problems, cardiac insufficiency, cardiac compression

21. Right Ventricular Pressure Normal is 0-5 (diastolic), 20-30 (systolic) • Indicates right ventricular function and fluid status • Increased with pulmonary hypertension, right ventricular failure, CHF

22. Circulatory Assist Devices • Used to decrease cardiac work and improve organ perfusion • Ventricles require support while recovering from acute injury • Pt must be stabilized before surgical repair • Heart has failed and pt is awaiting cardiac transplant • Intraaortic Balloon Pump (IABP) – most commonly used • Balloon is placed in the descending thoracic aorta above the renal arteries • Balloon fills with helium at start of diastole and deflates before systole (triggered by the ECG), counterpulsation – inflates opposite to ventricular contraction • Inflates with every heartbeat • Ventricular Assist Device (VAD) • Allows more mobility than the IABP • Placed internally or externally • Shunts blood from left atrium or ventricle to the device and then to the aorta