Dialysis Machine and Equipment Operation
Setup and safety systems
Verify machine disinfection status, install and prime the extracorporeal circuit, and confirm dialysate conductivity and temperature before connecting the patient. Know the alarms: arterial pressure (high suggests access or needle problem/occlusion; low suggests hypovolemia or pump-speed mismatch), venous pressure (high suggests infiltration, kink, or clotting; low suggests disconnection), transmembrane pressure (TMP), blood leak detector, air detector, and conductivity/temperature alarms.
Alarm response
For an air detector alarm, stop the blood pump and clamp lines; do not return blood until the cause is corrected. For a blood leak alarm, stop the pump and assess. Low conductivity means hypotonic dialysate and risk of hemolysis; high conductivity means hypertonic dialysate. Never bypass a safety alarm or override a limit without authorization.
Traps
Questions mix arterial and venous pressure meanings, or TMP with UF goal. TMP is the pressure gradient across the dialyzer membrane; UF control determines fluid removal. Another trap is treating a machine alarm as a patient problem, or vice versa-always assess the patient and the circuit.
Rule of thumb: alarm → stop or slow the pump if safety is threatened, identify the cause, correct it, then resume; document the event.