Efficacy of intravenous dexamethasone for the prevention of vomiting associated with intrathecal chemotherapy and ketamine sedation in children: a randomized, double-blinded, crossover, placebocontrolled trial.

Background: Chemotherapy-induced nausea and vomiting remains a significant problem for children with leukemia. There is limited evidence to support using prophylactic antiemetic prior to the administration of intrathecal chemotherapy. Objective: Determine whether vomiting and nausea associated with intravenous ketamine and intrathecal chemotherapy may be reduced by the addition of prophylactic dexamethasone in children. Method: A randomized, double-blinded, crossover, placebo-controlled trial was completed in 33 children receiving intrathecal chemotherapy with methotrexate and ketamine sedation at Pharmongkutklao Hospital. Patients were randomly assigned in a double-blinded fashion to receive one of two interventions during the first period, either an infusion of normal saline or intravenous dexamethasone at 0.25 mg/kg/dose. Each patient acted as his or her own control, and each patient was studied at two time-points. Results: Period effect, sequence effect, and carry over effect were not demonstrated. The absolute risk reduction of vomiting was significantly greater after infusion of dexamethasone than after placebo at 33.3 % (p=0.02). The number needed to treat was three to prevent one episode of vomiting. Fifteen patients in the treatment group reported nausea versus 26 patients in the placebo group (p= 0.007). In the group of patients treated with dexamethasone, five required antiemetic vs. 16 of those receiving placebo (p=0.02). There was no complication from dexamethasone. Conclusion: Intravenous dexamethasone reduced vomiting associated with intrathecal chemotherapy and ketamine sedation, without significant side-effects. It may be recommended a reasonable option before intrathecal chemotherapy.

Use of the gel test to follow up chimerism in ABO mismatched bone marrow transplantation patient: a case report.

OBJECTIVE: The authors report here our experience using the gel test to follow up chimerism in a 5 year old girl with beta thalassemia/Hemoglobin E disease (beta thal/HbE), post allogeneic bone marrow transplantation with Hb E trait HLA identical sibling donor. They were ABO blood group major mismatched donor-recipient pairs (donor and recipient blood group are B and O, respectively). MATERIAL AND METHOD: Pre and post transplanted EDTA blood samples from the girl with beta thalassemia/ Hemoglobin E were tested for ABO, Rh and direct antiglobulin test (DAT) using the A-B-AB-D-ctl/ AHG card and the titer of anti-A and anti-B were tested by the conventional tube technique. The sex chromosome study and hemoglobin typing were also examined. RESULTS: In this technique, mixed field agglutination is clearly identified from positive and negative results. The authors detected peripheral recovery, mixed O/B population after transplantation on day +26 with positive DAT. The DAT was negative on day +67 after transplantation and the recipient blood group was completely changed to B on day +123. In addition, Hb typing was changed to Hb E trait with Hb F less than 5 % on day +37. The engraftment of neutrophils, more than 5x10(9)/L, was detected on day+14 and platelet count was more than 20x10(9)/L on day +28. On day +90, the patient was transfusion-independent with the mean Hb level at 11.4 g/dL (10.4-13.1). The sex chromosome and hemoglobin typing were changed to the donor on day +300. CONCLUSION: The gel test is an alternative method which is simple and helpful in detecting mixed red blood cell populations, particularly in the ABO or other blood group mismatched bone marrow transplantation.

Laboratory approach in Thai patients with venous thrombosis.

This retrospective study aimed to analyze laboratory findings in Thai patients with venous thrombosis in Phramongkutklao Hospital from August 1997 to October 2004. Blood samples obtained from 166 patients with ages ranging from 10 months to 87 years were tested for protein S (PS), protein C (PC), antithrombin (AT), factor V Leiden (FVL) and prothrombin G20210A. It was found that low levels of PS, PC, and AT were observed in 23 patients (13.9%), 21 patients (12.7%) and 11 patients (6.6%), respectively. The incidence of combined low levels of anticoagulant factors occurred in 23 patients (13.9%). Three patients (1.8%) were positive for FVL. All patients were negative for prothrombin G20210A. Additionally, 85 patients (51.2%) were negative for all tests. In conclusion, it is recommended that the screening tests for anticoagulant factors PS, PC and AT be used to investigate the causes of thrombosis in Asian populations due to their cost-effectiveness. However, the detection of gene mutations inducing thrombosis should be considered.