Response to van Veen et al

Abstract

We note the retrospective report by van Veen et al on children with acute lymphoblastic leukaemia (ALL) with interest. When Task Forces of the British Committee for Standards in Haematology (BCSH) prepare guidelines for good practice, all available information is taken into account. It is accepted that the best evidence comes from randomized controlled clinical trials, but unfortunately there is often a dearth of such data in many areas of transfusion practice, for both children and adults. The Task Forces therefore have to refer to such information and studies as are available, which are mostly case reports and retrospective uncontrolled surveys. Among such reports is the account from Howard et al (2000), which evaluated 5223 lumbar punctures in 958 children with ALL at diagnosis and during treatment, and to which reference was made in the Guidelines for the Transfusion of Neonates and Older Children (BCSH, 2004). The relevant section in the BCSH Guidelines for the Transfusion of Neonates and Older Children (BCSH, 2004) (5.2.2. Platelets) includes the following statements (reference details are given in BCSH (2004): ‘In the absence of evidence-based guidelines for children, Table V reflects current recommended practice in children (Hume, 1996: level IIb evidence, grade B recommendation; Cahill & Lilleyman, 1998: level IV evidence, grade C recommendation; Ancliff & Machin, 1998: level IV evidence, grade C recommendation; Howard et al, 2000: level III evidence, grade B recommendation)…In children with aplasia, a restrictive policy with platelet transfusion is safe for long-term management (Sagmeister et al, 1999: level IV evidence, grade C recommendation). However, children with aplastic anaemia during and following treatment with ALG (antilymphocyte globulin) in particular may require intensive platelet support. In contrast, some paediatricians are prepared to conduct follow-up lumbar punctures on children with counts as low as 20 × 109/l, having not experienced unduly high adverse effects’. Table V of these Guidelines lists the indications for prophylactic platelet transfusion in children with thrombocytopenia as a result of reduced production (from any cause) and includes patients with a platelet count of 20–40 × 109/l prior to lumbar puncture (or central venous line insertion). It should be noted that this recommendation refers to a lumbar puncture performed in any setting. The BCSH Guidelines for the use of Platelet Transfusions (BCSH, 2003) state that there is a lack of evidence to guide decisions regarding platelet transfusions to cover invasive procedures, and that it is unlikely that comprehensive studies could be carried out because of the large number of variables involved. The BCSH guidelines indicate that work in this area is reviewed in the American Society of Clinical Oncology guidelines on platelet transfusion (Schiffer et al, 2001), including the papers by Edelson et al (1974) and Howard et al (2000). Schiffer et al (2001) pointed out that lumbar puncture is often more technically difficult in adults than in children, and that it is unclear whether the exemplary safety reported by Howard et al (2000) in children with ALL could be duplicated in adults. Guidance in the BCSH Guidelines for the use of Platelet Transfusions (BCSH, 2003) was given on the basis of this information and expert opinion, and included the recommendation that the platelet count should be raised to at least 50 × 109/l for lumbar puncture, epidural anaesthesia, gastroscopy and biopsy, insertion of indwelling lines, transbronchial biopsy, liver biopsy, laparotomy or similar procedures (grade B, level III). We do not demur from the advice from van Veen et al, given the specific circumstances affecting their patients, and we have acknowledged similar practice. We also acknowledge that transfusion of any blood component or product must be prescribed with the utmost care and consideration of long-term effects, especially in younger patients. Nevertheless, we do feel that the advice in the BCSH guidelines is founded on the best current information available.