INCREASED RISK OF HAEMORRHAGIC COMPLICATIONS IN RENAL ALLOGRAFT RECIPIENTS RECEIVING SYSTEMIC HEPARIN EARLY POST TRANSPLANTATION.

Abstract

P173 Aims: To document the risk of haemorrhagic complications in renal allograft (RA) recipients requiring systemic heparinisation within the first 2 weeks post transplantation, compared to RA recipients not requiring heparin. Methods: A retrospective review of the records of the 326 RA recipients from 1/1998-7/2003 was performed. Data obtained included recipient demographics, requirement for and dosing of systemic heparin, nature and management of haemorrhagic complications. Statistics were performed by SPIDA. A p value < 0.05 was considered significant. Results: 16/326(4.9%) of RA recipients were initiated on intravenous (iv) unfractionated heparin within the study period. Enoxaparin was subsequently used in 10/16(62.5%) of these recipients. There was no difference in age, sex or type of renal transplant between the RA recipients receiving IV Heparin versus non-heparinised RA recipients. Indications for heparin included- 9 pre-existing thrombotic disorder (6 clinical thrombotic episodes & documented thrombotic disorder, 3 clinical thrombotic episodes only), 4 mechanical heart valve, 2 intrarenal arterial branch thrombosis, 1 early pulmonary embolus. Intravenous heparin was instituted at a median 8(1-14) days post transplantation. Heparin was instituted at a dose of 500-1,000 IU per hour to maintain an APTT level within twice the normal range. Haemorrhagic complications occurred in 10/16(62.5%) of RA recipients on IV heparin versus 11/310(3.5%) of non-anticoagulated RA recipients [p=0.0001]. Haemorrhagic complications in the IV heparin group were 5-periallograft haemorrhage (2 episodes prior to initiation of iv heparin), 8 perigraft/retroperitoneal haematomas, and 1 gastrointestinal bleed. Haemorrhagic episodes in the non-heparinised RA recipients included 7-periallograft haemorrhage, 4 perigraft haematomas. Haemorrhage occurred at a mean 9.75(2-43) days into the course of IV Heparin. The median peak APTT 24 hours prior to haemorrhage in RA recipients on Heparin was 68.5(58-180) versus a median peak APTT of 70(50-140) in RA recipients on Heparin who did not sustain a haemorrhagic complication [p=0.30]. Major intervention (predominantly surgery) was required in 6/16(37%) of RA recipients on IV Heparin versus 7/310(2.2%) of non-heparinised RA recipients [p<0.0001]. Enoxaparin was instituted at a mean 22.5(4-55) days post transplantation. Delayed haemorrhage subsequently occurred in 4/10(40%) of RA recipients on Enoxaparin at a median 18.75(3-44) days into the course of Enoxaparin. Haemorrhagic complications on Enoxaparin included 2-periallograft haemorraghe (both requiring surgery), 1 retroperitoneal haematoma, and 1 deep thigh haematoma. Conclusions: Haemorrhagic complications of both a major and of a minor nature occur more commonly in RA recipients requiring early post transplantation IV Heparin. Haemorrhage occurred despite APTT monitoring with APTT levels tending to be similar in RA recipients with/without complications. Delayed haemorrhage was also seen with the subsequent use of Enoxaparin.