Bioeffects and Patient Care Flashcards
What are the main principles of medical ethics?
Respect for autonomy
Nonmaleficence
Beneficence
Justice
What does respect for autonomy mean?
The patient ahs the capacity to act with understanding and free will
What does nonmaleficence mean?
We avoid needless patient harm from our actions or nonactions
What does beneficence mean?
Our actions should benefit the patient and improve their health
What does justice mean?
Patients are all treated with fairness
What steps are involved in obtaining informed consent
informing the patient of the nature of the procedure, giving them reasonable alternatives, explaining the risks, benefits, and uncertainties, assessing their understanding, and obtaining their acceptance.
What should be done if the patient is under 18 or does not understand English?
The parent gives consent for those under 18
A translator should be provided for those that don’t understand English
Can consent be revoked once it has been given?
Yes
What are the first two things that you should do upon meeting a patient?
treat the patient respectfully by introducing yourself and explaining the procedure and what you will do, and identifying the patient by checking their wristband or asking for their name and date of birth.
How should you identify a sedated patient?
When a sedated patient arrives without a wristband, they need to be sent back to the nurse, and the study should be rescheduled for when they have proper identification
Should sonographers provide exam interpretation to patients?
No
What hygiene habits should sonographers employ?
Proper hand washing and the use of appropriate barrier precautions to prevent skin and mucous membrane exposure during contact with the patient. This includes PPE like gloves, gowns, eyewear, and face masks
What is patient dignity?
Their quality of feeling worthy, esteemed, or honored
What factors make the patient vulnerable to loss of dignity?
advanced age, infirmity, and lack of privacy
What is ergonomics?
They are the interactions between the sonographer, patient, and equipment to optimize the sonographer’s well being as they work.
What is OSHA?
The Occupational Safety and Health Administration. It works to implement precautions for workers, including classification of exposure risks, detailed work practice programs, and employer monitored criteria.
What is SDMS?
SDMS is the Society for Diagnostic Medical Sonography. It works to promote and educate healthcare workers about the science of diagnostic medical sonography.
What actions are considered best practices in sonographic ergonomics?
keeping their arm close to the body, staying close to the patient, positioning the monitor at eye level directly in front of you, minimizing twisting and bending, using correct sitting positions, holding the probe with palmar grip, keeping the wrist neutral, and proper foot support
What are examples of ergonomic devices?
wrist support braces, support cushions, cable braces, ergonomic transducers, and adjustable chairs and beds
What is a hydrophone?
Also called microprobe
A small transducer that measures the sound beam characteristics at a specific point
Similar to a hypodermic needle that contains a tiny piece of piezoelectric material at the end
What is a calorimeter and what does it measure?
device that measures the transducer output with absorption. It measures the total power of the sound beam through absorption
What is a thermocouple and what does it measure?
tiny electronic thermometer that is inserted into the sound beam. It measures the temperature or power of the sound beam at a particular location in the beam
What is the risk-benefit relationship?
the mandate regarding ultrasound that states that the benefits of the study to the patient have to outweigh any potential risks
Use ALARA
What is In Vivo?
a study is performed within a living body. It can be performed in living animals or humans.
What is In Vitro?
a study is performed outside the body. They occur in a petree dish, test tube, or on a computer
What is dosimetry?
the science of measuring and identifying the ultrasound beam characteristics that are relevant to the producing biological effects
What is the AIUM?
American Institute of Ultrasound in Medicine
- It works to gather scientific information about ultrasound specific procedures.
What is a mechanist approach?
approach that proposes that specific mechanisms have the potential to produce bioeffects. It searches for the relationship between cause and effect
What is an empirical approach?
approach based on acquisition and review of information from those animals or patients exposed to ultrasound. It searches for the relationship between exposure and response
With regard to mechanist and empirical approaches, when are the strongest conclusions made?
when the mechanical and empirical approaches are in agreement
What are the two mechanisms of bioeffects?
thermal and cavitation mechanisms
What is thermal mechanism?
when the bioeffects result from tissue temperature elevation. As sound propagates, energy is changed into heat and a increase tissue temperature
What is thermal index?
predictor for maximum temperature increase under clinically relevant conditions
Does soft tissue near to bone experience more or less heating?
more heating because the bone absorbs more acoustic energy
Are fetal or adult tissues more tolerant of heating?
Adult tissues
At what temp are no fetal bioeffects observed?
less than 39 degrees C
At what temperature and duration have no bioeffects of any kind observed?
at 2 degrees Celsius above normal for exposures less than 50 hours
What is the current maximal heating regulatory limit?
720 mW/cm2
What is cavitation?
sound wave interaction with microscopic, stabilized gas bubbles found in the tissue
What is another name for cavitation bubbles?
Gaseous nuclei
Is transient cavitation localized or wide spread?
Highly localized
What is a mechanical index?
calculated number that is related to the likelihood of harmful bioeffects that come from cavitation
What sound beam characteristics are related to the mechanical index?
peak rarefaction pressure and lower frequency
Do microbubbles burst during compression or rarefaction?
During compression because there is higher MI
What is an epidemiology study?
A population study that is empirical and utilizes clinical studies
What are three main limitations of epidemiology studies?
They are retrospective - backwards looking
There may be ambiguities in data
Risk factors can cause a bad outcome
What are two characteristics of the best epidemiological studies?
they are prospective, or forward looking, and that they are randomized, which creates two groups of patients
What are the 5 AIUM conclusions about clinical safety and prudent use of ultrasound?
- there are no confirmed harmful bioeffects from exposure to ultrasound that have been reported,
- bioeffects may be identified in the future
- the benefits to the patient outweigh the risks
- diagnostic ultrasound should be used prudently to benefit the patient
- it is not appropriate to use diagnostic ultrasound in a non-medical setting simply for entertainment
What causes the greatest risk of electrical shock from an ultrasound system?
comes from a cracked transducer housing.