The effective use of Heparin as an anticoagulant for patients undergoing Haemofiltration.
J. White & L.Byrne
Aim: the aim of this study was to examine the use of heparin as an anticoagulant in patients undergoing haemofiltration (CVVH) in a lead paediatric intensive care unit (PICU) in United Kingdom with specific reference to circuit life.
Methods: A retrospective review of all patients who received CVVH (n=16) in our PICU over a one year period commencing January 2009 were identified from our intensive care database and analysed. Patients were haemofiltered using the Aquarius Platinum machine (Edwards) with the HF03 and HF07 polysulphone filters at blood flow rates of 50, 100 and 150 ml/min for set patient weights.
Patients with normal coagulation - INR/APTT <2.0 and Platelets >50 have fixed rate of heparin 10iu/Kg/hr.
If APTT at 8 hours is >2.0 reduce heparin to 5iu/Kg/hr.
If APTT is persistently > 2.0 on 5iu/Kg/hr stop anticoagulant.
If coagulopathy – INR >2.0 APTT >2.0 or Platelets <50 or high risk of bleeding - no anticoagulation is given.
If patient is on heparin systemically do not use heparin on the CVVH circuit.
Demographic characteristics of patients receiving CVVH (n=16) included weight, length of ventilation(LOV), length of stay (LOS), survival, inotrope requirement, PIM score and underlying pathology. Data are expressed as median and inter-quartile range.
Results: 16 patients were identified from 1166 admissions. Case-mix of patients were sepsis (n = 2), cardiac (n = 3), acute renal failure (n = 5), chronic renal failure (n = 2), other (n=4). Median weight was 16kg (range 2.7-60kg).
Median LOV was 4.4 days (range 0.4 -15.9 days), median LOS was 5.7 days (range 1.1 -17 days), median PIM score 12.3 (range 0.5-70.7).
Of the 16 patients who received CVVH 76% survived, 88% were ventilated and 53% required inotropic support.
There were 37 circuit episodes for these 16 patients. Twenty-two of 37 circuits (62.1%) ran without complications (including clots). For these 22, 15 were on heparin 10iu/Kg/hr via CVVH, 2 were systemically anticoagulated and did not receive heparin via CVVH and 6 received no heparin.
The remaining 14 were discontinued early due to clots (3), high pressures (2) and 1 machine malfunction. For 6 circuits no reason was documented. Half (7/14) these circuits were heparinized with 10iu/kg/hr and half (7/14) received no heparin as per protocol. In all circuits with clots or high pressures, vascath position was considered suboptimal and repositioning was required.
Conclusions: The use of low dose heparin as an anticoagulant for CVVH circuits in the paediatric population is effective.
Evelina Children's Hospital,
Guys & St. Thomas NHS Foundation Trust
Westminster Bridge Road
Phone: 00442071884916 Fax: 0044207188