Technical and Environment Flashcards

What determines the surface area of a hollow fiber dialyzer?

Answer: All of the above

The total surface area of a hollow fiber dialyzer, crucial for efficient solute and fluid exchange, is determined by the collective dimensions of its fibers. A greater number of fibers, along with their individual length and internal diameter, directly contributes to a larger overall membrane surface area available for diffusion and ultrafiltration.

The purpose of using counter-current flow is to:

Answer: increase the rate of waste removal

Counter-current flow in a dialyzer involves blood and dialysate flowing in opposite directions. This arrangement maintains a maximal concentration gradient across the entire length of the membrane. This continuous gradient optimizes the efficiency of diffusion, significantly increasing the rate at which waste products are removed from the patient's blood.

Chloramine exposure in dialysis can result in:

Answer: hemolysis

Chloramines, used as disinfectants in tap water, must be completely removed from dialysis water. If chloramines enter the patient's bloodstream, they cause oxidative damage to red blood cells, leading to hemolysis. This rupture of red blood cells can result in severe anemia and other serious complications for the patient.

Part of the reuse process involves the reuse machine testing the dialyzer to verify:

Answer: the dialyzer fibers are free of leaks

During the dialyzer reuse process, a critical safety check performed by the reuse machine is to verify the integrity of the dialyzer fibers. This test ensures that there are no leaks in the membrane, preventing the mixing of blood and dialysate. Maintaining fiber integrity is essential for patient safety and the continued effectiveness of the dialyzer.

According to AAMI RD52, what is the maximum allowable level of bacteria in dialysate?

Answer: 200 CFU's

According to the Association for the Advancement of Medical Instrumentation (AAMI) RD52 standards, the maximum allowable level of bacteria in dialysate is 200 Colony Forming Units (CFU's) per milliliter. Adhering to this standard is vital to minimize the risk of bacterial contamination and prevent infections or pyrogenic reactions in hemodialysis patients.

According to AAMI RD52, how often should bacterial cultures be sampled?

Answer: Monthly

AAMI RD52 guidelines mandate that bacterial cultures for dialysate be sampled monthly. This regular monitoring ensures ongoing compliance with safety standards and helps detect any increases in bacterial levels promptly. Timely detection allows for intervention to prevent patient exposure to contaminated dialysate and potential infections.

Bacterial exposure to water may cause which of the following symptoms?

Answer: Fever/Chills

Exposure to bacteria or bacterial endotoxins in the dialysis water or dialysate can trigger a systemic inflammatory response in the patient. This reaction commonly manifests as fever and chills, which are classic symptoms of a pyrogenic reaction or infection. Prompt recognition and treatment are crucial to manage these potentially serious complications.

Who developed the first permanent blood access, the "Shunt"?

Answer: Scribner and Quinton

Belding Scribner and Wayne Quinton are recognized for developing the first permanent arteriovenous (AV) shunt in 1960. This innovation provided reliable, repeated access to a patient's bloodstream for long-term hemodialysis. Their work made chronic dialysis a practical treatment, significantly improving the prognosis for patients with end-stage renal disease.

Venous pressure meters are calibrated in:

Answer: mm/Hg

Venous pressure meters used in hemodialysis are calibrated in millimeters of mercury (mm/Hg). This unit is the standard measurement for blood pressure and other physiological pressures. Using mm/Hg provides a consistent and accurate way to monitor the pressure in the venous line, which reflects resistance to blood returning to the patient.

The hemodialysis machine continuously monitors many parameters. Which of these parameters must be verified by an external measuring device?

Answer: pH and conductivity

While hemodialysis machines monitor many parameters, pH and conductivity are critical for patient safety and must be independently verified by an external measuring device. This external check ensures the accuracy of the machine's internal sensors, confirming that the dialysate composition is within safe and prescribed limits to prevent patient harm.

The term pH is a measurement of the concentration of:

Answer: hydrogen ions

The term pH is a quantitative measure of the acidity or alkalinity of a solution. Specifically, it indicates the concentration of hydrogen ions (H+) present in the solution. A lower pH signifies a higher concentration of hydrogen ions (more acidic), while a higher pH indicates a lower concentration (more alkaline).