What are the causes of abnormal access / return pressures in a RRT circuit?

Return Pressure
Access Pressure
Low
  • Low blood pump speed
  • Line disconnection
  • Pre-sensor line is clamped
  • Catheter related:
    • Kinked
    • Against a vessel wall
    • Occluded with clot
  • Patient related – leading to poor flow:
    • Hypovolaemia
    • ↑ intrabdominal / intrathoracic pressure
    • Hyperventilation
High
Catheter related:
  • Kinked
  • Against a vessel wall
  • Occluded with clot
  • Dislodged (Emptying into a haematoma)
  • Inadvertent arterial insertion