TY - JOUR
T1 - Haematocrit monitoring and blood volume estimation during continuous renal replacement therapy
AU - Baldwin, Ian
AU - Maeda, Akinori
AU - Bellomo, Rinaldo
AU - See, Emily
N1 - Funding Information:
The authors thank the ICU technical and nursing teams for their support with this initiative. Peter Kennedy for adaptor design and tech support, (CEO, TekMed, Melbourne).
Publisher Copyright:
© 2023 Australian College of Critical Care Nurses Ltd
PY - 2024/7
Y1 - 2024/7
N2 - Background: Continuous haemoglobin, venous blood oxygen saturation, and haematocrit (Hct) monitoring is currently not applied during continuous renal replacement therapy (CRRT). Such Hct monitoring enables estimation of changes in blood volume as percentage change (ΔBV%) from therapy start time and is incorporated into intermittent haemodialysis machines but not CRRT machines despite its potential to optimise fluid management in CRRT patients. Methods: To overcome this problem, we used a standalone monitor (CRIT-LINE®IV, Fresenius Medical Care, Concord, USA) with an associated in-line blood chamber (CRIT-LINE®IV Blood Chamber, Fresenius Medical Care, Concord, USA) and designed our own adaptor connection piece (TekMed and Morriset, Melbourne and Brisbane, Australia) to allow these readings at the vascular access outflow and recorded data for estimated Hct and derived ΔBV% during CRRT. Results: We report on this technique with an illustrative case example and 12 h of CRRT data on the fluid loss rate prescribed, hourly net patient fluid loss (range: 0–308 mL/h), mean arterial pressure, norepinephrine dose (range: 5–14 mcg/min), estimated continuous Hct and ΔBV%, and the otherwise undetected diagnosis of an approximate 15 % decrease in blood volume during the CRRT. Conclusion: We have described a technical CRRT circuit modification that can facilitate a previously unavailable assessment of fluid shifts during CRRT. Further application in clinical trials is now possible.
AB - Background: Continuous haemoglobin, venous blood oxygen saturation, and haematocrit (Hct) monitoring is currently not applied during continuous renal replacement therapy (CRRT). Such Hct monitoring enables estimation of changes in blood volume as percentage change (ΔBV%) from therapy start time and is incorporated into intermittent haemodialysis machines but not CRRT machines despite its potential to optimise fluid management in CRRT patients. Methods: To overcome this problem, we used a standalone monitor (CRIT-LINE®IV, Fresenius Medical Care, Concord, USA) with an associated in-line blood chamber (CRIT-LINE®IV Blood Chamber, Fresenius Medical Care, Concord, USA) and designed our own adaptor connection piece (TekMed and Morriset, Melbourne and Brisbane, Australia) to allow these readings at the vascular access outflow and recorded data for estimated Hct and derived ΔBV% during CRRT. Results: We report on this technique with an illustrative case example and 12 h of CRRT data on the fluid loss rate prescribed, hourly net patient fluid loss (range: 0–308 mL/h), mean arterial pressure, norepinephrine dose (range: 5–14 mcg/min), estimated continuous Hct and ΔBV%, and the otherwise undetected diagnosis of an approximate 15 % decrease in blood volume during the CRRT. Conclusion: We have described a technical CRRT circuit modification that can facilitate a previously unavailable assessment of fluid shifts during CRRT. Further application in clinical trials is now possible.
KW - Acute kidney injury
KW - Fluid balance
KW - Haematocrit
KW - Methods
KW - Net ultrafiltration rate
KW - Relative blood volume
UR - https://www.scopus.com/pages/publications/85183015262
U2 - 10.1016/j.aucc.2023.11.005
DO - 10.1016/j.aucc.2023.11.005
M3 - Article
C2 - 38245397
AN - SCOPUS:85183015262
SN - 1036-7314
VL - 37
SP - 632
EP - 637
JO - Australian Critical Care
JF - Australian Critical Care
IS - 4
ER -