Unexpected triggering of the dialysate blood leak detector by haemolysis

Abstract

2Blood Bank, Leeds Teaching Hospitals NHS Trust, Leeds, UK This case showed that it is possible for haemoglobin released by haemolysis in the extracorporeal circuit to pass through a high permeability (albumin retaining) dialyser membrane. In the incident described, the blood leak detector of the dialysis machine was activated before the patient became symptomatic. Haemolysis should be considered as a possible cause of blood leak alarms during dialysis with high flux membranes

High-dose hydroxocobalamin for vasoplegic syndrome causing false blood leak alarm

“…Depending on the manufacturer, this may be accomplished by infrared or colorimetric photodetection [1]. True blood leak culprits include dialyzer membrane compromise, heat sterilization for dialysis reprocessing [17, 18], aged dialyzer [19], dialyzer reuse [18] and hemolysis, especially when using high-flux dialyzers [3] (Table 1). Also, air bubbles or deposits of grease or scale on the detector may cause a false blood leak alarm.…”

“…Thus modern dialysis machines have been designed to cease operations when blood is detected in the dialysate [2]. The blood leak detector is placed in the dialysis solution outflow line and uses a sensor in the dialysate effluent path [3–5]. When a blood leak develops through the dialyzer membrane, an alarm is activated and blood flow through the dialyzer stops.…”

“…Blood leak alarms typically occur due to physical damage caused by mishandled dialyzers. False blood leak alarms usually result from air bubbles or hardware issues (such as deposits of grease or scale on the sensor) [3]. …”

Haemolysis in haemodialysis

“…Visual inspection of the circuit may reveal that the blood in the circuit appears brighter and less opaque (port wine or cherry red). In cases of massive haemolysis, the dialysate fluid may appear pink tinged, owing to dialysate fluid contamination with free Hb, usually associated with high flux membranes with very large pores …”

“…In cases of massive haemolysis, the dialysate fluid may appear pink tinged, owing to dialysate fluid contamination with free Hb, usually associated with high flux membranes with very large pores. 79 Simultaneous decrease in both the arterial and venous pressures in the circuit may indicate a kinked tube. 10 Declining haematocrit, pink serum, and rise in blood pressure > 30 mmHg from baseline are other useful markers.…”