Mixed Deck — All CHBT Topics Flashcards

Which sign indicates possible stenosis in an arteriovenous fistula?

Answer: High venous pressure during dialysis combined with a decreased thrill distal to the stenosis

Stenosis restricts flow, causing elevated venous pressure as blood backs up behind the obstruction. The thrill (vibration) is diminished distal to the narrowing. This warrants referral for imaging (fistulogram) and possible angioplasty.

When a dialysis patient experiences an adverse event such as a blood leak or machine malfunction during treatment, the technician is required to:

Answer: Document the event in the patient's treatment record and complete a facility incident report per policy

Adverse events must be documented in both the patient's treatment record and an incident report to support quality review, regulatory compliance, and prevention of future occurrences.

Which of the following is the most critical immediate action when a patient on hemodialysis develops sudden hypotension?

Answer: Place the patient in the Trendelenburg position and administer a normal saline bolus

Sudden hypotension during hemodialysis is managed by placing the patient in Trendelenburg position (legs elevated) and administering a normal saline bolus to restore circulating volume. Increasing ultrafiltration would worsen hypotension.

What does 'standard precautions' require in a dialysis setting?

Answer: Treating all blood, body fluids, non-intact skin, and mucous membranes as potentially infectious regardless of patient diagnosis

Standard precautions apply universally to all patients. This includes hand hygiene, appropriate PPE (gloves for blood/fluid contact, gown/eye protection when splash risk exists), safe needle handling, and environmental cleaning.

Why should blood pressure never be measured in the arm containing an arteriovenous fistula?

Answer: Cuff compression can restrict fistula blood flow and potentially cause thrombosis

BP cuff inflation compresses the fistula, interrupting high-volume flow and risking thrombosis. Additionally, venipuncture, IV lines, and tight clothing are also contraindicated in the fistula arm.

What is the primary safety risk if chloramines are not adequately removed from dialysis water?

Answer: Hemolytic anemia from chloramine crossing the dialyzer membrane and destroying red blood cells

Chloramines pass freely through dialyzer membranes, entering the bloodstream and oxidizing red blood cell membranes, causing hemolysis and potentially fatal anemia.

Which mechanism does the kidney use to regulate systemic blood pressure?

Answer: The renin-angiotensin-aldosterone system (RAAS)

The kidney releases renin, triggering the RAAS cascade that ultimately increases angiotensin II and aldosterone to raise blood pressure and retain sodium.

When performing preventive maintenance on a hemodialysis machine, what electrical test measures the resistance between the equipment chassis and the ground pin of the power cord?

Answer: Ground continuity test

The ground continuity (protective earth resistance) test measures the resistance of the safety ground path from the equipment chassis to the power cord ground pin, which should typically be less than 0.1 ohm.

Standard precautions in hemodialysis require that blood and body fluids from ALL patients be treated as:

Answer: Potentially infectious regardless of diagnosis or perceived risk

Standard precautions treat all blood and body fluids as potentially infectious to protect staff and patients regardless of known infection status.

Which vaccine is specifically recommended for all susceptible hemodialysis staff and patients due to the high risk of HBV transmission in dialysis units?

Answer: Hepatitis B vaccine series with post-vaccination serologic testing to confirm immunity (anti-HBs ≥10 mIU/mL)

HBV vaccination is mandatory for dialysis staff and strongly recommended for patients. Post-vaccination testing confirms protective antibody levels (anti-HBs ≥10 mIU/mL). Dialysis patients may have a blunted immune response and require higher-dose or additional booster doses.

In the event of a power failure during hemodialysis, what is the first priority?

Answer: Return blood to the patient using the hand crank or gravity if available, and ensure patient safety

During power failure, blood in the extracorporeal circuit must be returned to the patient to prevent blood loss and circuit clotting. Most machines have a manual blood pump crank for this purpose. Patient safety is the primary concern.

Which of the following dialyzers is used currently?

Answer: Hollow tube

Modern dialyzers predominantly use a hollow fiber (or hollow tube) design. These dialyzers contain thousands of tiny, semi-permeable hollow fibers through which blood flows. Dialysate flows around the outside of these fibers, allowing for efficient exchange of waste products and excess fluid across the membrane. This design maximizes surface area for filtration.

A technician notices the RO machine's product water conductivity has suddenly increased from 5 µS/cm to 45 µS/cm. What is the most likely cause?

Answer: RO membrane failure or bypass, allowing unfiltered water to pass through

A sudden spike in product water conductivity indicates that dissolved solids are passing through the RO system. This most commonly points to membrane failure, a bypass valve left open, or a broken O-ring seal. Treatment must not proceed until resolved.

What is the consequence of using dialysate with too low a sodium concentration?

Answer: Hyponatremia, hypotension, muscle cramps, and risk of cerebral edema

Hypotonic dialysate pulls sodium from the blood, causing hyponatremia that leads to osmotic fluid shifts, cramping, hypotension, and potentially dangerous cerebral edema.

Methicillin-resistant Staphylococcus aureus (MRSA) colonization is detected in a dialysis patient. What precautions should be implemented?

Answer: Contact precautions: gown and gloves for all interactions, dedicated equipment, and enhanced environmental cleaning

MRSA requires contact precautions because it is transmitted primarily by direct or indirect contact with contaminated surfaces and colonized patients. Gown and gloves reduce transmission, along with enhanced cleaning of the patient's station.

How should a water treatment technician document findings from daily water quality checks?

Answer: In a dated log that records test results, operator initials, and any corrective actions taken

All water quality test results must be recorded in a dedicated logbook with date, time, results, operator initials, and corrective actions. This documentation is reviewed during regulatory inspections (CMS, state agencies).

The potassium concentration in hemodialysis dialysate is typically set at:

Answer: 1–4 mEq/L, individualized to the patient's pre-dialysis serum potassium

Dialysate potassium is individualized based on pre-treatment serum levels to safely remove excess potassium without causing dangerous hypokalemia.

Which acid-base disturbance is most common in patients with ESRD?

Answer: Metabolic acidosis

ESRD patients develop metabolic acidosis because the kidneys lose the ability to excrete hydrogen ions and regenerate bicarbonate.

The ultrafiltration coefficient of a dialyzer refers to the:

Answer: fluid that passes through the membrane in 1 hour.

The ultrafiltration coefficient (Kuf) of a dialyzer measures its permeability to water. It indicates how much fluid (in milliliters) will be removed from the blood across the dialyzer membrane per hour for every mmHg of transmembrane pressure. This value is crucial for calculating and controlling the amount of fluid removed from a patient during dialysis.

In the context of hemodialysis equipment, what does 'macroshock' refer to?

Answer: Current above 1 mA applied to the skin surface

Macroshock refers to currents above approximately 1 mA that are perceptible at the skin surface and can cause muscle contraction, respiratory arrest, or ventricular fibrillation at higher levels.