Comprehensive Study Notes on Hemodialysis Access, Protocols, and Safety

Arteriovenous Access: AVF and AVG

  • Arteriovenous Fistula (ADF/AVF)

    • The procedure does not involve cutting the ends of the vessels; instead, the artery and the vein are joined together (anastomosis).

    • Both vessels are producing flow once the connection is established.

  • Arteriovenous Graft (AVG)

    • In the case of an AVG, the dialysis needle punctures the graft itself to facilitate the blood draw and return.

    • The graft provides the necessary access point for the procedure.

  • Catheter Usage

    • A triple lumen catheter is only used for dialysis when specified.

    • If a catheter has only a double lumen, it may not be suitable for the same procedures as a triple lumen.

Dialysis Scheduling and Interruption

  • Interruption Protocol

    • If it becomes necessary to stop dialysis prematurely (e.g., a session starting on Wednesday), the patient generally does not resume the same day.

    • The procedure is typically continued on the next scheduled dialysis day (e.g., Friday), rather than trying to finish the interrupted session on the same day.

Laboratory Monitoring and Timing

  • Lab Value Assessments

    • Laboratory tests are not monitored continuously throughout the dialysis procedure.

    • Routine labs for dialysis patients are typically drawn early the next morning following the procedure.

    • Patients at dialysis clinics do not typically sit and wait for lab results at the clinic; the monitoring happens on a delayed schedule.

Anticoagulation Management

  • Heparin Administration

    • Heparin is used during dialysis to prevent clotting when the patient has a tendency to clot.

    • The heparin is administered directly into the dialysis machine, not as a shot (subcutaneous or intramuscular) to the patient.

    • The goal is to maintain the patency of the dialysis circuit, not to anticoagulate the patient’s entire systemic circulation outside the machine context.

Infection Control and Hepatitis B

  • Surface Stability of Pathogens

    • The Hepatitis B virus is highly resilient and can remain infectious on environmental surfaces for at least 77 days or more.

  • Clinical Anecdote: Scope Contamination

    • A specific incident occurred in an ICU where a bedside endoscopy was performed.

    • The medical team forgot to clean the scope after it was used on a patient with Hepatitis B.

    • The contaminated scope was subsequently used on another patient, leading to significant disciplinary trouble for the staff involved due to the risk of cross-contamination.

  • Vaccination Recommendations

    • The Hepatitis B (Hep B) vaccine is recommended for all patients and healthcare workers.

    • While recommended and important for testing/safety protocols, it is noted that the vaccine may not be strictly mandatory for nurses in all jurisdictions, though it is highly encouraged.

Complications and Contraindications

  • Hypotension (Low Blood Pressure)

    • Low blood pressure is a primary complication and often a contraindication for the dialysis procedure.

    • Hemodialysis involves significant fluid shifts which can exacerbate low blood pressure.

  • Hemodialysis Prevalence

    • Approximately 90%90\% of patients requiring renal replacement therapy are on hemodialysis.

  • Safety in Emergency Settings

    • A major clinical error can occur if an unconscious patient is brought in and subjected to a CT scan with contrast without the staff knowing they are a dialysis patient.

    • Identifying a dialysis patient in an emergency is crucial because contrast media can be nephrotoxic or problematic for those with end-stage renal disease.

Questions and Discussion

  • Question: For the Lab values, is that going on continuously throughout the procedure, or do you have to wait?

  • Response: We will do the next morning. Next morning, early morning, we take the labs.

  • Question: If it is necessary to stop the dialysis, would you just continue it the next dialysis day?

  • Response: Yes. Only on the scheduled days. You would not do it the same day.

  • Question: Is the heparin given as a shot to the patient?

  • Response: No. It is not a heparin shot. We are giving heparin to the machine, not to the patient.

  • Question: How long can Hepatitis B sit on a surface?

  • Response: Seven days. More than seven days.

  • Question: What is the reason for low blood pressure being a concern?

  • Response: This is related to the overview of why we do hemodialysis (to be covered in the following week's material).