Online Hemoglobin and Oxygen Saturation Sensing During Continuous Renal Replacement Therapy with Regional Citrate Anticoagulation

Abstract

Optical hemoglobin and oxygen saturation sensor (OHOS) monitor when used in combination with other hemodynamic tools may be useful for continuous hemodynamic monitoring during ultrafiltration. The stand-alone OHOS monitor can easily be deployed predialyzer into the extracorporeal circuit of continuous renal replacement therapy (CRRT) systems. To maximize the accuracy of the OHOS in 24 hr CRRT systems, clotting in the optical blood chamber and the presensor dilution incurred by replacement fluid should be minimized. Sustained low-efficiency dialysis (SLED) with regional citrate anticoagulation is a therapy that incorporates an OHOS and maintains the overall reliability of hemoglobin (Hb) and saturation sensing. The system operates at a blood flow rate of 60 ml/min and a fixed acid citrate infusion rate of 150 ml/hr. The presensor dilution incurred by concentrated citrate infusion would result in a minimal Hb dilution (<0.7 g/dl) while minimizing optical blood chamber clotting during 24 hr SLED.

Regional citrate anticoagulation for continuous renal replacement therapy without post-filter monitoring of ionized calcium

“…Regional citrate anticoagulation Regional citrate anticoagulation (RCA) is an attractive candidate to achieve this goal (10)(11)(12)(13). However, RCA may potentially add substantially to the complexity of an already complicated technology, impeding acceptance and utilizing excessive resources (11,14).…”

Relative Blood Volume Monitoring during Renal Replacement Therapy in Critically Ill Patients with Septic Shock: A Preliminary Report

“…Possible dilution by infusions upstream of the chamber has to be avoided. The combination with venous oxygen saturation measurement is an additional advantage of this device [22] .…”

Innovations in CKRT: individualized therapy with fewer complications

“…CKRT systems have the potential to be used diagnostically as continuous blood sampling devices. For example, incorporation of an existing IHD optical chamber and sensor into a CKRT circuit in combination with RCA enabled continuous monitoring of central venous haemoglobin level and oxygen saturation (ScVO 2 ) at minimal cost and without invasive procedural risk 9 . Data on ScVO 2 trends could help to identify relative changes in cardiac output.…”