Critical Care (Cardiac)
Megan McClintock, MS, RN
Winter 2012
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
Common Problems of ICU Patients
• Venous thromboembolism d/t immobility
• Skin problems d/t immobility
• Nutritional deficiencies d/t hypermetabolic 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
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
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
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)
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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