Topic: Clinical Trial
Trans-membrane pressure (TMP) and 24 hour filter patency (24FP) in high vs low dose citrate regimens in citrate continuous veno-venous hemofiltration (CVVH).
Willaert, Xavier; Vander Laenen, Margot; Vanelderen, Pascal; Boer, Willem
Dept. of Anesthesiology, Intensive Care, Emergency Medicine and Pain Therapy, Ziekenhuis Oost-Limburg, Genk, Belgium
Abstract:
Introduction. In (citrate) CVVH, TMP pressure alarms indicate a change in the pressure across the membrane between the blood and ultrafiltrate compartments and an increase can precede impending filter loss due to clotting. As part of a study comparing the effects of high dose citrate vs. low dose citrate in regional anticoagulation in citrate CVVH on Calcium balance over the first 24 hours therapy, TMP and 24FP were compared between the 2 groups.
Methods. In this prospective randomized study, 20 patients admitted to intensive care, requiring continuous renal replacement therapy (CRRT) for AKI were included. After informed consent, patients were randomized to low dose citrate (2.5 mmol/L blood flow in the filter) or high dose citrate (4.5 mmol/L blood flow in the filter) as anti-coagulant, targeting a post-filter ionized Calcium (iCa) of 1.3-1.6 mg/dL (0.325-0.4 mmol/L) and 0.8-1.1 mg/dL (0.2-0.275 mmol/L) respectively and titrated accordingly. Substitution volumes were set at a total of 30 ml/kg/h after correction for filtration fraction due to prefilter administration of citrate buffer solution. 24FP and trends in TMP from 1 to 24 hours were then compared between the 2 groups. TMP was registered at 1, 6, 12,18 and 24 hrs. The 1hr TMP was used as a baseline to calculate changes specified in percentages of later TMP values at 6,12,18 and 24 hours.
Results. A total of 20 patients were included (high=10, low=10) in the study. In the high group, 6 men and 4 women were included, whereas in the low group 8 men versus 2 women were included (p=0,355). There was no significant difference in age, weight and initial values for total and ionized calcium between the 2 groups. The mean citrate target in the high group was 5.02 (±0.35) mmol/L, in the low group 3.19 (±0.37) (p<0.001), resulting in a mean post-filter iCa of resp. 1.03 (±1.22) and 1.62 (±0.23) (p<0.001). In the high group all filters survived for 24 hours (24FP 100%), in the low group 1 failed at 22 hours, though this failure was assigned to a catheter problem and not to primary clotting of the filter (24FP 90%). Compared to baseline TMP, % change of TMP was more pronounced in the low citrate group (median +33,7 % IQR 32,7) compared to the high group (median +15,1%, IQR 27,5, p=0,01). Six rises in TMP above +60% were recorded, all in the low group, in all cases with a measured iCa above 1,3 mg/dL (0,325 mmol/L). There is a weak, though statistically significant correlation between iCa and %TMP change (r=0,299, p<0,01).
Conclusion. Increase in TMP, a precursor for filter loss due to clotting, was significantly higher in the low citrate group, despite only weak correlation between iCa and TMP increase. The limited 24 hour follow up of this study undoubtedly impeded the proper study of the effects of low vs. high citrate on FP. A study targeting FP longer than 72 hours, with citrate and iCA targets (<1.3 mg/dL) based on these findings, could prove helpful in the development of a low dose/low monitoring citrate CVVH protocol.
References:
Citrate anticoagulation for extracorporeal circuits: effects on whole blood coagulation activation and clot formation. Calatzis A, Toepfer M, Schramm W, Spannagl M, Schiffl H. Nephron. 2001 Oct;89(2):233-6.
Topic: Clinical Trial
Trans-membrane pressure (TMP) and 24 hour filter patency (24FP) in high vs low dose citrate regimens in citrate continuous veno-venous hemofiltration (CVVH).
Willaert, Xavier; Vander Laenen, Margot; Vanelderen, Pascal; Boer, Willem
Dept. of Anesthesiology, Intensive Care, Emergency Medicine and Pain Therapy, Ziekenhuis Oost-Limburg, Genk, Belgium
Abstract:
Introduction. In (citrate) CVVH, TMP pressure alarms indicate a change in the pressure across the membrane between the blood and ultrafiltrate compartments and an increase can precede impending filter loss due to clotting. As part of a study comparing the effects of high dose citrate vs. low dose citrate in regional anticoagulation in citrate CVVH on Calcium balance over the first 24 hours therapy, TMP and 24FP were compared between the 2 groups.
Methods. In this prospective randomized study, 20 patients admitted to intensive care, requiring continuous renal replacement therapy (CRRT) for AKI were included. After informed consent, patients were randomized to low dose citrate (2.5 mmol/L blood flow in the filter) or high dose citrate (4.5 mmol/L blood flow in the filter) as anti-coagulant, targeting a post-filter ionized Calcium (iCa) of 1.3-1.6 mg/dL (0.325-0.4 mmol/L) and 0.8-1.1 mg/dL (0.2-0.275 mmol/L) respectively and titrated accordingly. Substitution volumes were set at a total of 30 ml/kg/h after correction for filtration fraction due to prefilter administration of citrate buffer solution. 24FP and trends in TMP from 1 to 24 hours were then compared between the 2 groups. TMP was registered at 1, 6, 12,18 and 24 hrs. The 1hr TMP was used as a baseline to calculate changes specified in percentages of later TMP values at 6,12,18 and 24 hours.
Results. A total of 20 patients were included (high=10, low=10) in the study. In the high group, 6 men and 4 women were included, whereas in the low group 8 men versus 2 women were included (p=0,355). There was no significant difference in age, weight and initial values for total and ionized calcium between the 2 groups. The mean citrate target in the high group was 5.02 (±0.35) mmol/L, in the low group 3.19 (±0.37) (p<0.001), resulting in a mean post-filter iCa of resp. 1.03 (±1.22) and 1.62 (±0.23) (p<0.001). In the high group all filters survived for 24 hours (24FP 100%), in the low group 1 failed at 22 hours, though this failure was assigned to a catheter problem and not to primary clotting of the filter (24FP 90%). Compared to baseline TMP, % change of TMP was more pronounced in the low citrate group (median +33,7 % IQR 32,7) compared to the high group (median +15,1%, IQR 27,5, p=0,01). Six rises in TMP above +60% were recorded, all in the low group, in all cases with a measured iCa above 1,3 mg/dL (0,325 mmol/L). There is a weak, though statistically significant correlation between iCa and %TMP change (r=0,299, p<0,01).
Conclusion. Increase in TMP, a precursor for filter loss due to clotting, was significantly higher in the low citrate group, despite only weak correlation between iCa and TMP increase. The limited 24 hour follow up of this study undoubtedly impeded the proper study of the effects of low vs. high citrate on FP. A study targeting FP longer than 72 hours, with citrate and iCA targets (<1.3 mg/dL) based on these findings, could prove helpful in the development of a low dose/low monitoring citrate CVVH protocol.
References:
Citrate anticoagulation for extracorporeal circuits: effects on whole blood coagulation activation and clot formation. Calatzis A, Toepfer M, Schramm W, Spannagl M, Schiffl H. Nephron. 2001 Oct;89(2):233-6.
Topic: Clinical Trial
Trans-membrane pressure (TMP) and 24 hour filter patency (24FP) in high vs low dose citrate regimens in citrate continuous veno-venous hemofiltration (CVVH).
Willaert, Xavier; Vander Laenen, Margot; Vanelderen, Pascal; Boer, Willem
Dept. of Anesthesiology, Intensive Care, Emergency Medicine and Pain Therapy, Ziekenhuis Oost-Limburg, Genk, Belgium
Abstract:
Introduction. In (citrate) CVVH, TMP pressure alarms indicate a change in the pressure across the membrane between the blood and ultrafiltrate compartments and an increase can precede impending filter loss due to clotting. As part of a study comparing the effects of high dose citrate vs. low dose citrate in regional anticoagulation in citrate CVVH on Calcium balance over the first 24 hours therapy, TMP and 24FP were compared between the 2 groups.
Methods. In this prospective randomized study, 20 patients admitted to intensive care, requiring continuous renal replacement therapy (CRRT) for AKI were included. After informed consent, patients were randomized to low dose citrate (2.5 mmol/L blood flow in the filter) or high dose citrate (4.5 mmol/L blood flow in the filter) as anti-coagulant, targeting a post-filter ionized Calcium (iCa) of 1.3-1.6 mg/dL (0.325-0.4 mmol/L) and 0.8-1.1 mg/dL (0.2-0.275 mmol/L) respectively and titrated accordingly. Substitution volumes were set at a total of 30 ml/kg/h after correction for filtration fraction due to prefilter administration of citrate buffer solution. 24FP and trends in TMP from 1 to 24 hours were then compared between the 2 groups. TMP was registered at 1, 6, 12,18 and 24 hrs. The 1hr TMP was used as a baseline to calculate changes specified in percentages of later TMP values at 6,12,18 and 24 hours.
Results. A total of 20 patients were included (high=10, low=10) in the study. In the high group, 6 men and 4 women were included, whereas in the low group 8 men versus 2 women were included (p=0,355). There was no significant difference in age, weight and initial values for total and ionized calcium between the 2 groups. The mean citrate target in the high group was 5.02 (±0.35) mmol/L, in the low group 3.19 (±0.37) (p<0.001), resulting in a mean post-filter iCa of resp. 1.03 (±1.22) and 1.62 (±0.23) (p<0.001). In the high group all filters survived for 24 hours (24FP 100%), in the low group 1 failed at 22 hours, though this failure was assigned to a catheter problem and not to primary clotting of the filter (24FP 90%). Compared to baseline TMP, % change of TMP was more pronounced in the low citrate group (median +33,7 % IQR 32,7) compared to the high group (median +15,1%, IQR 27,5, p=0,01). Six rises in TMP above +60% were recorded, all in the low group, in all cases with a measured iCa above 1,3 mg/dL (0,325 mmol/L). There is a weak, though statistically significant correlation between iCa and %TMP change (r=0,299, p<0,01).
Conclusion. Increase in TMP, a precursor for filter loss due to clotting, was significantly higher in the low citrate group, despite only weak correlation between iCa and TMP increase. The limited 24 hour follow up of this study undoubtedly impeded the proper study of the effects of low vs. high citrate on FP. A study targeting FP longer than 72 hours, with citrate and iCA targets (<1.3 mg/dL) based on these findings, could prove helpful in the development of a low dose/low monitoring citrate CVVH protocol.
References:
Citrate anticoagulation for extracorporeal circuits: effects on whole blood coagulation activation and clot formation. Calatzis A, Toepfer M, Schramm W, Spannagl M, Schiffl H. Nephron. 2001 Oct;89(2):233-6.
Topic: Clinical Trial
Trans-membrane pressure (TMP) and 24 hour filter patency (24FP) in high vs low dose citrate regimens in citrate continuous veno-venous hemofiltration (CVVH).
Willaert, Xavier; Vander Laenen, Margot; Vanelderen, Pascal; Boer, Willem
Dept. of Anesthesiology, Intensive Care, Emergency Medicine and Pain Therapy, Ziekenhuis Oost-Limburg, Genk, Belgium
Abstract:
Introduction. In (citrate) CVVH, TMP pressure alarms indicate a change in the pressure across the membrane between the blood and ultrafiltrate compartments and an increase can precede impending filter loss due to clotting. As part of a study comparing the effects of high dose citrate vs. low dose citrate in regional anticoagulation in citrate CVVH on Calcium balance over the first 24 hours therapy, TMP and 24FP were compared between the 2 groups.
Methods. In this prospective randomized study, 20 patients admitted to intensive care, requiring continuous renal replacement therapy (CRRT) for AKI were included. After informed consent, patients were randomized to low dose citrate (2.5 mmol/L blood flow in the filter) or high dose citrate (4.5 mmol/L blood flow in the filter) as anti-coagulant, targeting a post-filter ionized Calcium (iCa) of 1.3-1.6 mg/dL (0.325-0.4 mmol/L) and 0.8-1.1 mg/dL (0.2-0.275 mmol/L) respectively and titrated accordingly. Substitution volumes were set at a total of 30 ml/kg/h after correction for filtration fraction due to prefilter administration of citrate buffer solution. 24FP and trends in TMP from 1 to 24 hours were then compared between the 2 groups. TMP was registered at 1, 6, 12,18 and 24 hrs. The 1hr TMP was used as a baseline to calculate changes specified in percentages of later TMP values at 6,12,18 and 24 hours.
Results. A total of 20 patients were included (high=10, low=10) in the study. In the high group, 6 men and 4 women were included, whereas in the low group 8 men versus 2 women were included (p=0,355). There was no significant difference in age, weight and initial values for total and ionized calcium between the 2 groups. The mean citrate target in the high group was 5.02 (±0.35) mmol/L, in the low group 3.19 (±0.37) (p<0.001), resulting in a mean post-filter iCa of resp. 1.03 (±1.22) and 1.62 (±0.23) (p<0.001). In the high group all filters survived for 24 hours (24FP 100%), in the low group 1 failed at 22 hours, though this failure was assigned to a catheter problem and not to primary clotting of the filter (24FP 90%). Compared to baseline TMP, % change of TMP was more pronounced in the low citrate group (median +33,7 % IQR 32,7) compared to the high group (median +15,1%, IQR 27,5, p=0,01). Six rises in TMP above +60% were recorded, all in the low group, in all cases with a measured iCa above 1,3 mg/dL (0,325 mmol/L). There is a weak, though statistically significant correlation between iCa and %TMP change (r=0,299, p<0,01).
Conclusion. Increase in TMP, a precursor for filter loss due to clotting, was significantly higher in the low citrate group, despite only weak correlation between iCa and TMP increase. The limited 24 hour follow up of this study undoubtedly impeded the proper study of the effects of low vs. high citrate on FP. A study targeting FP longer than 72 hours, with citrate and iCA targets (<1.3 mg/dL) based on these findings, could prove helpful in the development of a low dose/low monitoring citrate CVVH protocol.
References:
Citrate anticoagulation for extracorporeal circuits: effects on whole blood coagulation activation and clot formation. Calatzis A, Toepfer M, Schramm W, Spannagl M, Schiffl H. Nephron. 2001 Oct;89(2):233-6.
