Chapter 8 Hemodynamic Monitoring Flashcards
- Hemodynamic monitoring common in critical care unit
* Studies relationships among several variables:
- Heart rate
- Blood flow
- Oxygen delivery
- Tissue perfusion
Cardiovascular system • Pressure = • Pressure— • Flow: • Resistance:
- Pressure = flow × resistance
- Pressure—force exerted on the liquid
- mm Hg
- Flow: amount of fluid moved over time
- L/min or mL/min
- Resistance: opposition to flow
CARDIAC OUTPUT • Cardiac output: • CO = • Ejection fraction— • Normal:
• Cardiac output—volume of blood ejected from heart/min
• CO = HR × Stroke volume (volume of blood ejected with each beat)
• 4 to 8 L/min
• Ejection fraction—fraction of blood ejected with
each beat
• Normal 60% to 70%
PRELOAD • Degree of? • Volume of blood in? • Frank-Starling law • Example =
- Degree of muscle fibers’ stretch before systole
- Volume of blood in ventricle prior to contraction (LVEDV/LVEDP)
- Frank-Starling law
- Increased stretch = increased volume
- Stretch is within physiological limits
- Example = balloon
AFTERLOAD • Pressure or? • Related to? • Systemic vascular resistance? • Pulmonary vascular resistance? • Example =
• Pressure or resistance against flow
• Related to lumen size and viscosity
• Systemic vascular resistance: Force overcome by the left ventricle upon contraction
• Pulmonary vascular resistance: Force overcome by the right ventricle upon contraction
• Example = opening door against wind
CONTRACTILITY

- Force of ventricular contraction
* How well the heart is pumping
SYSTEMIC VASCULAR RESISTANCE (SVR)
- Peripheral vascular resistance
- Diameter of blood vessels
- Arterial BP = CO × SVR
CARDIAC OUTPUT VERSUS INDEX
• Index is a better assessment; based on?
• CI =
• Calculated on?
- Index is a better assessment; based on body size
- CI = CO ÷ body surface area
- Calculated on the computer after entering patient’s height and weight
HEMODYNAMIC MONITORING
• Noninvasive modalities
• Noninvasive blood pressure
• Assessment of jugular venous pressure
• Assessment of serum lactate levels (to see if the patient is meeting their metabolic needs).
-normal they will go to med surg or tele
-elevated they need more intensive care
-correlation/indicator if patient will decompensate and crash
central venous pressure normal range
Normal is 7 to 9 cm
HEMODYNAMIC MONITORING
• Invasive modalities
- Arterial pressure monitoring
- Pulmonary artery pressure monitoring
- Right atrial pressure monitoring
COMPONENTS OF INVASIVE HEMODYNAMIC MONITORING (5)
- Invasive catheter
- Noncompliant pressure tubing
- Transducer and stopcocks
- Flush system
- Bedside monitor
ACCURACY IN HEMODYNAMIC MONITORING
• Level =
• Zero reference
• Dynamic response testing
• Level = phlebostatic axis
• Fourth intercostal space, midaxillary line
• Approximate level of right atrium
• Zero reference
• Negate atmospheric pressure
• Zeroing stopcock is leveled at phlebostatic axis and “zeroed”
• Dynamic response testing
• Square wave test (to make sure tube is in proper place and you are getting right reading from it)
-always assess patient and make sure your readings are accurate
ARTERIAL PRESSURE MONITORING
Invasive technique to monitor arterial blood pressure
• Sites:
1) Radial artery
• Allen’s test prior to insertion to verify collateral circulation in the extremity
• Issues related to predictability of Allen’s test
2) Brachial artery
3) Femoral artery
ARTERIAL PRESSURE MONITORING
• Equipment
- Pressurized flush solution with transducer
- Pressure at 300 mm Hg (Why does this need to be high?) because it has to counteract their blood pressure.
- A-line catheter (angiocath)
Arterial Pressure Monitoring Complications
Major complications 1) Thrombosis • Clot if flush not used appropriately 2) Embolism • Air entering system/clot dislodgment 3) Hemorrhage • Loose connections/catheter dislodgment (they can loose blood rapidly) 4) Infection (can have phlebitis of artery itself)
RAP/CVP MONITORING

1) Right atrial pressure (RAP)—catheter in right atrium
• Proximal port of pulmonary artery catheter
2) Central venous pressure (CVP)—catheter in superior or inferior vena cava
• Triple lumen
- Values similar and terms interchanged
RAP/CVP
• Direct measurement of?
• Right ventricular (RV) preload or?
• Normal value
- Direct measurement of pressure in right atrium
- Right ventricular (RV) preload or right ventricular end diastolic pressure (RVEDP)
- Normal value: 2 to 6 mm Hg
- Recorded end exhalation as a mean value
NURSING IMPLICATIONS RAP/CVP
- Zero/balance
- Wave form analysis
- Respiratory variation and PEEP
- Patient position: Head of bed between 0 and 60 degrees
- Correlate values with assessment
- Monitor for complications
COMPLICATIONS OF RAP/CVP
- Infection
- Pneumothorax or hemothorax
- Carotid puncture
- Heart perforation
- Dysrhythmias
Which patient would benefit the most from central venous/right atrial pressure monitoring?
A. Patient admitted in cardiogenic shock
B. Patient admitted with a bowel obstruction
C. Patient taking routine doses of furosemide
D. Patient receiving two units of blood
B.
A. can also be one too
PULMONARY ARTERY CATHETER
• Flow-directed catheter
• Variations
1) Flow-directed catheter • Inserted via subclavian, internal jugular, or femoral vein • Balloon tipped • Multiple lumens 2) Variations • SvO2 catheter • Continuous cardiac output (CCO)
INSERTION OF PA CATHETER • Proper position of patient • Trendelenburg common • Towel roll between shoulder blades • Inserted with balloon deflated, selected inflation to “float” catheter into PA • Waveform changes as catheter progresses • Check for proper “wedging” for PAOP • Chest x-ray
INSERTION OF PA CATHETER • Proper position of patient • Trendelenburg common • Towel roll between shoulder blades • Inserted with balloon deflated, selected inflation to “float” catheter into PA • Waveform changes as catheter progresses • Check for proper “wedging” for PAOP • Chest x-ray
INSERTION OF PA CATHETER
• Proper position of patient
• Trendelenburg common
• Towel roll between shoulder blades
• Inserted with balloon deflated, selected inflation to “float” catheter into PA
• Waveform changes as catheter progresses
• Check for proper “wedging” for PAOP
• Chest x-ray
PULMONARY ARTERY CATHETER
• Measurement capabilities
• PA systolic • PA diastolic • PAOP/PCWP/PAWP - Inflated balloon flows into wedge position in pulmonary capillary, measuring pressure • Cardiac Output/Index - ThermodilutionCO - Proximal injectate port
NURSING IMPLICATIONS
• Mr. Smith’s condition continues to deteriorate. His attending physician arrives in the unit to insert a pulmonary artery catheter.
• What is the nurse’s role prior to the insertion of the pulmonary artery catheter?
• After implementing the central line bundle, the physician prepares to insert the catheter.
• What is the nurse’s role during the insertion of the catheter?
- prepare patient
- do they need sedation?
- have all pressurized tubing set up and primed
- after implementation take care of insertion site
- make sure no infection
- no autowedge
- make sure pressure bags are good
NURSING IMPLICATIONS
• Measure pulmonary artery pressures
- Pulmonary artery occlusive pressure (PAOP) reflects left ventricular end-diastolic pressure
- In many patients the PADP can be substituted for PAOP measurements if values are similar
- Record amount of air to inflate balloon— no more than 1.5 mL (small amount, we don’t want to overinflate and cause injury to pulmonary artery itself)
COMPLICATIONS OF PA CATHETERS
- Infection
- Dysrhythmias
- Air embolus
- Thromboembolism
- Pulmonary artery (PA) rupture
- Pulmonary infarction
The nurse prepares to measure pulmonary artery pressures in Mr. Smith. Based on Mr. Smith’s diagnosis of cardiogenic shock, which values should the nurse anticipate? A. Decreased PAP; decreased PAOP. B. Increased PAOP; decreased CO. C. Increased CO; increased PAOP. D. Decreased PAOP; elevated CI.
B. Increased PAOP; decreased CO
MONITORING O DELIVERY AND CONSUMPTION 2

- Calculated values
- Obtained via monitoring catheters
- SvO2—mixed venous oxygen saturation via specialized PAC
- ScvO2—central venous oxygen saturation via specialized central line
MONITORING O DELIVERY AND 2 CONSUMPTION • Normal values • High values = • Low values =
• Normal values
• SvO2—60%-75% = adequate balance between
supply and demand
• ScvO2—65%-85% = adequate balance between supply and demand
• High values = tissues not able to use oxygen
• Low values = oxygen demand exceeds delivery
MONITORING O2 DELIVERY AND CONSUMPTION 2

- Calculated values
- Obtained via monitoring catheters
- SvO2—mixed venous oxygen saturation via specialized PAC
- ScvO2—central venous oxygen saturation via specialized central line
MONITORING O2 DELIVERY AND 2 CONSUMPTION • Normal values • High values = • Low values =
- Normal values
- SvO2—60%-75% = adequate balance between supply and demand
- ScvO2—65%-85% = adequate balance between supply and demand
- High values = tissues not able to use/extract oxygen
- Low values = oxygen demand exceeds delivery
DOPPLER TECHNOLOGY METHODS
1) Echocardiography
2) Esophageal Doppler Monitoring (EDM)
• Placement
• Monitoring
• Outcomes
PULSE CONTOUR METHOD
- Less risk than a PA catheter
- Better predictor of fluid responsiveness in mechanically ventilated patients
- Full mechanical ventilation
PASSIVE LEG RAISING (PLR)

- Done to determine preload-responsiveness
* Completed prior to IV fluid challenges
Related to lumen size and viscosity
Afterload
Pressure or resistance against flow
Afterload
Force overcome by the left ventricle upon contraction
Systemic vascular resistance
Force overcome by the right ventricle upon contraction
Pulmonary vascular resistance
Force of ventricular contraction
-how well the heart is pumping
Contractility
Systemic vascular resistance (SVR)
- Peripheral vascular resistance
- Diameter of blood vessels
Medications that are vasodilators for humoral regulation
- Prostaglandins
- Kinins
- Endothelial- derived factors (nitric oxide)
Medications that are vasoconstrictors for humoral regulation
- Angiotensin
- Epinephrine
- Ca++
- Endothelial- derived factors
Pulmonary artery montioring
its in the major blood vessels of the lung
