Topic 5.3 and 5.4 (Introduction to Therapeutic Devices) Flashcards
(23 cards)
How do we treat Kidney failure?
we use artificial kidneys ( Hemodialysis machines ) to help the kidney to remove metabolic waste from patients blood
What does the Hemodialysis comprise of?
It comprise of 2 compartments one side with blood and the other side with dialysate and also a semi permeable membrane
Which side of the Hemodialysis machine should have lower concentration?
Dialysate side because it help to move and filter the blood through osmosis and diffusion
Why is the flow of dialysate from top to bottom while blood flows from bottom to top? (Opposite)
It is to maintain the concentration gradient against the semi permeable membrane so that the dialysis is efficient
Which side of the Hemodialysis machine should have higher pressure?
the blood side as it require a little bit more of pressure to induce the filtration to happen.
( Hydrostatic pressure )
What are the 3 Basic Physical Process of Hemodialysis machine?
1) Osmosis : water flow through semi permeable membrane to more concentrated side
2) Diffusion: solutes move from high to low side through semi permeable membrane
3) Ultra filtration: need a bit of hydrostatic pressure to induce filtering like filter paper
What does the dialysate contain that helps filtering?
The dialysate contains lower concentrations of undesired solutes like potassium, calcium and urea which are high in the blood so that these solute can diffuse to the dialysate
How do we increase the speed of the hemodialysis machine?
we can change the concentration of various substances in the dialysate so that the desire speed of exchange is attained
What are the 3 main purpose of electronics in hemodialysis machine?
1) Detecting leaks in membrane
2) Ensuring the correct concentration of electrolytes in dialysate
3) Prevent air bubble that maybe life threatening
what are the 3 types of sensor use for the 3 main purpose of electronics in hemodialysis machine?
1) Colorimetric to detect change in color of dialysate as it is colorless
2) Measure conductivity of dialysate by using test
3) Use air bubble detector
What is the typical temperature the dialyzer is kept at and why?
40 degrees Celsius to prevent thermal shock
What is Peritoneal dialysis used for?
Ambulatory use ( use at home and portable )
How does Peritoneal dialysis work?
The dialysate is pump into the peritoneal cavity of the person and left to slosh about. the thin membrane of the internal organ will allow for exchange of molecules between the Dialysate and capillaries and it is than drained out after some time.
What is a Ventilator?
It is a machine used to assist breathing for patients facing reduced breathing or respiratory failure
What are the 3 parts of mechanical ventilator?
(Ambu Bag)
1) Mask ( fitted to patients mouth )
2) Breathing valve ( conduct oxygen to patient and conduct expired air away )
3) Self-filling bag ( function as pump to fill with air and oxygen )
What are Machine ventilators used for?
it is used when prolonged artificial ventilation is needed. example during anaesthesia to replicated natural respiration as close as possible
What are the 2 types of Machine ventilators?
1) Negative Pressure
2) Positive Pressure
How does negative pressure ventilators work?
it created negative pressure around the patients thoracic cage, reducing the pressure inside the lungs vs atmosphere hence air goes into lungs
Why is Negative pressure ventilators not popular?
It is very difficult to move and access the patient for critical care and it also has some engineering problems
How does Positive Pressure Ventilator work?
During Inspiration the exhalation system close the outlet to the atmospheric pressure and the inspiratory flow delivery system creates an internal pressure greater than the atmosphere in the airway circuit and during exhalation the IFDS stop increasing pressure and the Exhalation control system opens outlet for atmospheric pressure to be part of the airway circuit
What are the 2 modes of Positive Pressure Ventilator?
1) Mandatory Mode
2) Spontaneous Mode
What is Mandatory Mode?
Ventilator control all the parameters of breathing because patient cannot breath on their own
What is Spontaneous Mode?
Ventilator respond to patient’s effort to breath and compensate accordingly. used for recovering patient who have some breathing ability
