Midterm - NONINVASIVE HEMODYNAMIC MONITORING Flashcards
There are three major types of noninvasive hemodynamic monitoring methods:
transesophageal echocardiography,
carbon dioxide elimination (V# CO2), and
impedance cardiography (ICG)
_____ provides diagnosis and monitoring of many structural and functional abnormalities of the heart.
Transesophageal echocardiography
(Transesophageal echocardiography) It can also be used to calculate cardiac output from measurement of blood flow velocity by recording the ____ of ultrasound.
Doppler shift
The time velocity integral obtained for the blood flow in the left ventricular outflow tract (e.g., descending aorta) is multiplied by the _____ and the heart rate to yield the cardiac output.
cross sectional area
This ____ technique requires a highly skilled technician to obtain accurate readings
Doppler
The _______ procedure may be done at the bedside, and continuous readings are available with this procedure.
transesophageal echocardiography
A ______ is placed into the esophagus (via the mouth or nose) with its distal end resting at the midthoracic level.
Doppler transducer probe
The ____ is rotated until it faces the aorta and is able to pick up the aortic blood flow signal.
probe / Doppler transducer probe
the cardiac output measured by this technique correlates well with the measurements using the traditional _____
thermodilution method
_______ : A method using a Doppler transducer in the esophagus for an indirect measurement of the blood flow velocity in the descending aorta and the calculation of the cardiac output and other hemodynamic data.
transesophageal echocardiog- raphy
_____ (VCO2) is a technology that can monitor and mea- sure cardiac output based on changes in respiratory CO2 concentration during a brief period of rebreathing.
Carbon dioxide elimination
The ____ (with cardiac output option) is a cardio- pulmonary management system that incorporates different sensors to measure the flow, airway pressure, and CO2 concentration.
NICO2
These measurements are used to calculate CO2 elimination.
flow, airway pressure, and CO2 concentration.
A ____ partial rebreathing method is used to derive the cardiac output.
Fick
The original Fick method uses the ____ (VO2) and ______ difference (C(a-v)O2) to calculate the cardiac output.
oxygen consumption / arterial- mixed venous oxygen content
This method for calculating cardiac output requires the use of specialized equipment and has never been suitable in the traditional clinical setting.
Carbon dioxide elimination
The NICO2 uses ___ instead of VO2
VCO2
_____ from an exhaled breath sample is used instead of using mixed venous and arterial blood samples (for C(a-v)O2).
End-tidal CO2
The ______ (Respironics®) can provide continuous cardiac output noninvasively via this method.
NICO system
____ A technology to monitor and measure cardiac output based on changes in respiratory CO2 concentration during a period of rebreathing.
carbon dioxide elimination
___ , also called thoracic electrical bioimpedance (TEB), is a major division of noninvasive technique for hemodynamic monitoring.
Impedance cardiography (ICG)
___ is based on a technology originally used by NASA in the 1960s.
ICG / IMPEDANCE CARDIOGRAPHY
The introduction of the microprocessor and the working knowledge of echocardiography and magnetic resonance imaging make ____ possible.
ICG
____ is a noninvasive procedure to measure or trend the hemodynamic status of a patient in clinical settings ranging from critical care to outpatient care.
ICG
Several noninvasive ____ devices are available and each offers different technology to measure and calculate the hemodynamic values.
ICG
The_____ uses a patented signal processing technique to identify the opening and closing of the aortic valve for the precise measurement of the ventricular ejection time (VET).
IQ system
Another device incorporates “ _____” to estimate the VET by using the QRS of the ECG and the raw dZ/dt (change in impedance/time) waveform
ensemble averaging
A third manufacturer of ICG uses ______ and an ____ system to establish the dZ/dt.
digital signal processing / R-wave detection
____ has proven to be a simple and accurate method to measure and monitor a patient’s hemodynamic status
ICG
_____ :
A noninvasive procedure to mea- sure or trend the hemodynamic status of a patient.
impedance cardiography (ICG)
___ uses external electrodes to input a high frequency, low amplitude cur- rent and to measure changes of electrical resistance (impedance) in the thorax.
ICG
In a typical setup, ___ and ____ electrodes are placed on the patient,
four outer / four inner
The____ transmit a constant, low amplitude electrical current through the thorax.
outer electrodes
The _____ measure the impedance (resistance) to the electrical signal according to the changing blood flow in the aorta.
inner electrodes
The ___ and ___ of blood flow in the ascending aorta changes with each cardiac cycle
volume and velocity
increasing volume and velocity during ___ and decreasing volume and velocity during ___.
systole / asystole
Since the impedance changes reflect the blood flow in the ______, the changes in blood velocity are calculated and reported as values for different hemodynamic parameters.
ascending aorta
____ uses external electrodes to input a high frequency, low amplitude cur- rent and measure changes of electrical resistance (imped- ance) in the thorax.
ICG
Since the impedance changes reflect the blood flow in the ascending aorta during ___ and ___, the changes in blood velocity are calculated and reported as values for different hemodynamic parameters.
systole and asystole
_____ is the most commonly used invasive technique for measuring and calculating the hemodynamic values.
Thermodilution
The accuracy and reliability of this method rely on the proper (and correct) computation constant, injectate volume, injectate temperature measurement, injection technique, timing of injection, and averaging strategies
Thermodilution
Since the ____ method provides hemodynamic measurements in a limited time frame, it cannot be used to monitor the dynamic nature of the cardiovascular system.
thermodilution
The noninvasive nature of ____ makes it an ideal tool to monitor a patient’s hemodynamic status.
ICG
Some of the measured and calculated hemodynamic parameters provided by ICG include: _______
cardiac output, cardiac index, stroke volume, stroke volume index, systemic vascular resistance, systemic vascular resistance index, contractility, and fluid status.
the thermodilution method in which a ____ is required,
pulmonary artery catheter
ICG cannot provide the values for ______
pulmonary artery pressure, pulmonary artery wedge pressure, pulmonary vascular resistance, and pulmonary vascular resistance index.
In a study of patients with pulmonary arterial hypertension, the correlation of cardiac output determined by ICG versus the Fick method and the thermodilution method were ___ and ___, respectively
0.84 and 0.80
___ is less variable and more reproducible than other invasive methods,
ICG
it has shown sufficient clinical usefulness to become a standard practice in noninvasive hemodynamic evaluations
ICG
While ___ is useful in many clinical situations, there are some technical reasons and conditions that may influence the use and accuracy of __
ICG
They include wrong placement of electrodes; _____ (cachetic or obese); _____ (.120/min); _____
abnormal body structure (cachetic or obese); tachycardia (.120/min); presence of pacemaker; arrhythmias; open-heart or aorta surgery; abnormal cardiac anatomy (e.g., transpo- sitions, aneurysms); abnormal hematocrit; and pleural effusion.
With ICG, the therapeutic effects of fluid administration and resuscitation can be assessed by monitoring the ___ and ____
stroke volume and cardiac output.
____ has also been used to evaluate the hemodynamic status of critically ill patients in the inten- sive care units, surgical areas, and outpatient and emergency departments
ICG
Evaluation and follow-up of patients with acute myocardial infarction is also possible with ____
ICG
In subacute care, adjustment of the dosages of cardiovascular drugs can be done by monitoring the____ , ____, and ____
thoracic fluid status, stroke volume, and cardiac output
Since ___ monitoring is noninvasive, it can be used in outpatients as well as patients at home.
ICG
___ provides these advantages: noninvasive continuous monitoring, rapid diagnosis and assessment of cardiopulmonary status, hemodynamic response to fluids and drugs, and availability outside the critical care area.
ICG
Advantages of Impedance Cardiography
Reduces risk associated with invasive hemodynamic monitoring procedures
Provides rapid diagnosis and assessment of cardiopulmonary status
Offers continuous noninvasive hemodynamic monitoring
Monitors patient’s hemodynamic response to fluids and drugs
Reduces use and risk associated with PA catheterization
Reduces cost over invasive hemodynamic monitoring procedures
Provides availability outside the hospital
