Ch. 11 Pilbeams Flashcards
The primary indication of hemodynamic monitoring is:
Critically ill patients who demonstrate evidence of compromised cardiovascular function.
Measurements typically include:
• systemic arterial pressure (SAP)
• central venous pressure (CVP)
• pulmonary artery pressures (PAP)
• arterial and mixed venous blood gases
• cardiac output
Once obtained these measurements can be used to calculate:
• oxygen (O2)
• oxygen delivery (DO2)
• cardiac index (CI)
• vascular resistance
• cardiac work
Measurements can also be used to:
Better define abnormalities in cardiopulmonary function and ultimately guide therapeutic interventions
The outputs of the right and left ventricle are ultimately influenced by four main factors:
• heart rate
• preload
• contractility
• afterload
Heart range can range from ____to ____ in a normal healthy adult
50 to 200
What is preload?
The filling pressure of the ventricle at the end of ventricular diastole
What is contractility?
The force that the ventricle generates during each cardiac cycle
How can contractility be estimated?
The ejection fraction
How is the ejection fraction calculated?
As the ratio of SV to the ventricular end diastolic volume
What is afterload?
The impedance that the left and right ventricles must overcome to eject blood into the great vessels
Impedance is described as?
Systemic and pulmonary vascular resistances
What is SVR?
the afterload that the left ventricle must overcome to eject blood into the systemic circulation.
What is PVR?
the afterload that the right ventricle must overcome to eject blood into the pulmonary circulation.
Direct measurement of the systemic arterial pressure requires the insertion of a catheter into:
A peripheral artery such as:
• radial artery
• brachial artery
• femoral artery
What are central venous lines:
Catheters places in the vena cava or right atria
CVP catheters are usually inserted percutaneously into:
• a large central vein (internal jugular)
• peripherally through the medial basilic
• lateral cephalic vein
What is the normal CVP?
2 to 6 mmHg
What is this image? Fig.11.4
Balloon-tipped, flow directed right-sided heart catheter
Label this image: Fig 11.4
- Ballon inflation valve
- Thermistor connector
- Thermistor
- Proximal lumen
- Proximal injection port
- Distal lumen
- Ballon
- Extra injection port
- Distal injection port
What does PAOP stand for?
Pulmonary artery occlusion pressure
What does PCWP stand for?
Pulmonary capillary wedge pressure
Are PAOP and PCWP the same?
Yes
What is PAOP?
When you inflate the ballon to get a reading
Should you leave the ballon inflated after getting a reading for PAOP?
NO!!!!
Could cause an myocardial infarction (MI)
To measure pressure accurately transducer must be:
At the same height or level as the catheter tip
PAOP, which reflects preload of the left side of the heart, is a valuable parameter to monitor when performing an…?
Optimum PEEP study
If PAOP increases significantly during the study, it could indicate:
Overinflation of alveoli
The most common problem associated with CVP catheters is:
Pneumothorax
Balloon tipped flow directed catheters are also known as?
Swan Ganz Catheter or pulmonary artery catheter
The standard adult catheter is how long and comes in what sizes?
110 cm ; sizes 7&8 French
Catheters are marked in _____ cm increments?
10
_________ have one lumen that connects to a balloon located near the tip of the catheter and a second lumen that runs the length of the catheter and terminates at a port at the distal end of the catheter.
Dual lumen catheters
________have an additional proximal port that terminates approximately 30 cm from the tip of the catheter, or at the level of the right atrium.
Triple lumen catheters
This third lumen can be used to measure right atrial pressures or for administrating intravenous medications.
________incorporate a thermistor connector, which contains electrical wires that connect to a thermistor located approximately_______from the tip of the catheter
Thermodilution ; 1.5 inches (3cm)
When measuring cardiac output using the thermodilution technique,__________(cold or room temperature) is injected through the catheter’s third (proximal) lumen, which is positioned ________.
a bolus of saline or 5% dextrose ; at the level of the right atrium.
What is a normal heart rate?
60-100 bpm
Bradycardia is what?
Heart rate < 60 bpm
What is tachycardia?
HR > 100bpm
What is the normal range for systolic pressure in adults?
90 to 140 mmHg
What is the normal range for diastolic pressure for an adult?
60-90 mmHg
What is the normal mean arterial pressure (MAP)?
70-100 mmHg
What is systemic hypertension?
Systolic arterial pressure greater than 140 mmHg and diastolic pressure greater than 90 mmHg
What is systemic hypotension?
Systolic pressure is less than 100 mmHg and diastolic pressure is less than 60 mmHg
What is pulse pressure?
Systolic pressure - diastolic pressure
A wide pulse pressure is associated with what?
An increased stroke volume and a decreased arterial compliance
What is a narrow pulse pressure associated with?
Decreased stroke volume and increase arterial compliance
What is the range for PAOP?
5 to 12 mmHg
PAOP greater than 25 mmHg means what?
Cardiogenic pulmonary edema from left sided heart failure
What is the normal PA systolic pressure for a healthy adult?
15 to 35 mmHg
What is the normal PA diastolic pressure for an adult?
5 to 15 mmHg
PAOP plays a major role in the assessment of?
Pulmonary hydrostatic pressure in the formation of pulmonary edema
PAOP can help distinguish the difference between?
Cardiogenic pulmonary edema and non-cardiogenic pulmonary edema
PEEP greater than 15 cmH2O can produce what?
Erroneously elevated pressure readings
What is cardiac output?
Volume of blood that is pumped by the heart per minute
Usually expressed in liters per minute or milliliters per minute
What is the normal range for cardiac output?
4-8L/min
How can cardiac output be calculated?
SV x HR
What is the formula for cardiac index?
CI=Q/BSA
What is the formula for stroke index?
SI=SV/BSA
What is normal cardiac index for an adult?
2.5 to 4 L/min/m2
What is the normal range for a stroke index?
35-55mL/beat/m2
What is the Fick principle?
Q=VO2/(CaO2-CvO2) x 10
Cardiac output involves direct measurements of what?
• O2 consumption
• arterial and mixed venous O2 contents
What is the normal SvO2?
75%
What is the normal CvO2?
15vol% (150mL/L of whole blood)
Mixed venous oxygen value declines when arterial oxygenation is________?
Decreased
With a reduced cardiac output more time is available for the extraction of_____ from blood delivered to the tissues?
O2
Mixed venous oxygen values can be higher than normal in patients with________?
Histotoxic hypoxia & in situations with pulmonary shunting
DO2 is the product of _____?
Cardiac output and arterial oxygen content
DO2 represents?
The total amount of oxygen that is carried in the blood to the tissues each minute
DO2 is approximately?
1000mL or about 550 to 650 mL/min/m2
DO2 is increased in situations in which_____?
Cardiac output or arterial oxygen content is elevated
A reduced DO2 indicate a decrease in what?
Cardiac output or arterial O2 content
DO2 is increased in?
Hyperdynamic states (increase cardiac output) such as septic shock
What is a shunt?
A portion of cardiac output that does not participate in gas exchange with alveolar air (perfusion without ventilation)
Shunts are usually identified as:
• anatomical shunts
• intrapulmonary shunts
• physiological shunts
latter being the sum of anatomical and intrapulmonary shunts
What is the normal range for a shunt?
2 to 3% of normal cardiac output
What is the equation for physiological shunt?
Qs/Qt= (CcO2 - CaO2)/CcO2-CvO2
Why do we multiply SVR and PVR by 80?
To convert the units from mmHg/L/min to dyne x second x cm^-5
SVR will increase as ______ increases?
Blood viscosity
(occurs in polycythemia)
SVR decreases during?
Systemic vasodilation
occurs with moderate hypoxemia or after administration of systemic vasodilators such as nitroglycerin or hydralazine
PVR increases during what?
• Periods of alveolar hypoxia
• When high intraalveolar pressures are generated such as during positive pressure ventilation
What is the normal EF value?
50-70%
During ventricular systole or atrial diastole when the tricuspid valve is CLOSED the pressure measured in the right atrium or vena cava reflects_____
Right atrial pressure (RAP)
At the end of ventricular diastole and atrial systole when the tricuspid valve is OPEN the pressure measured in the right atrium reflects ________
Right ventricular pressure (RVP).
What is the standard size and length for pediatric catheters?
60 cm in length; size 4 and 5 French
What is the rate that flush runs through the catheter?
1-5 mL/h
It is important to fully inflate balloon to avoid?
• endocardial pulmonary artery damage
• induced ventricular arrhythmias
What is the balloon volume for a pediatric catheter?
0.8 mL
What is the balloon volume for an adult catheter?
1.5 mL
The balloon should only be inflated for how long when measuring PAOP?
15 to 30 seconds
particularly in patients with pulmonary hypertension
What is the indicator for left ventricular preload?
Left ventricular and diastolic pressure (LVEDP)
What is the indicator for contractility?
Ejection fraction
What is the indicator for afterload?
SVR and PVR