Gestation-specific D-dimer reference ranges: a cross-sectional study.

OBJECTIVE: To establish a gestation-specific reference range for D-dimer in healthy pregnant women with a singleton pregnancy using the Auto-Dimer assay. DESIGN: Cross-sectional study SETTING: Cork University Maternity Hospital, Ireland. POPULATION: Healthy pregnant women attending for routine antenatal care. METHODS: Simultaneous-quantile regression was performed to construct a median, 5th percentile, and 95th percentile, model of normal pregnancy D-dimer concentration versus gestational week, ranging from week 6 to 42. Additionally, pair-wise Mann-Whitney U-tests were performed to compare distributions of D-dimer concentrations for each of the four discrete gestational sampling windows with the distribution of D-dimer concentrations 48 hours postpartum. MAIN OUTCOME MEASURES: D-dimer concentrations (ng/ml) during normal gestation (approximately week 6 to week 42). RESULTS: Seven hundred and sixty healthy pregnant women were investigated between gestational age week 5 and 48 hours postpartum. There was a clear steady increase in median D-dimer concentrations over the complete gestational period. Additionally, the 95th centile estimates for all gestational time-points were above the accepted non-pregnancy normal cut-off concentration (224 ng/ml). The results of the Mann-Whitney U-tests suggested that the long-term postnatal return to normal D-dimer concentrations begins in the immediate postpartum period. CONCLUSIONS: We found that there is a continuous increase in D-dimer concentrations across all gestations. This research is potentially beneficial to future diagnosis of venous thromboembolism (VTE) in pregnancy using the new recommended 95th centile potential cut-offs. Possible further investigation involves an observational study comparing D-dimer concentrations in women with proven DVT with those that don't, generating likelihood ratios.

Thromboprophylaxis in myeloma: what is happening outside of clinical trials?

Patients with myeloma are at high risk of venous thromboembolism (VTE). There is no consensus about what agent to use or what haematologists are doing in clinical practice. A survey was sent to haematologists treating patients with myeloma in Ireland. 32/45 (71%) responded. 13/28 (46%) felt that VTE affected < 5% of patients. However, 8/28 (29%) felt it affected 10-19%. Thromboprophylaxis was most commonly used in patients on lenalidomide; 25/28 (89%) and thalidomide; 23/28 (82%). 23/28 (82%) used LMWH and 20/28 (71%) used aspirin either very frequently or frequently. 3/28 (11%) had used dabigatran/rivaroxaban despite there being little evidence to support their use. Efficacy was the most important factor in choosing an agent for 25/28 (89%). Bleeding was not felt to be an issue 15/29 (52%) were not using thromboprophylaxis guidelines. This survey demonstrated wide variation in the beliefs and practices regarding the burden of VTE in patients with myeloma and the need for thromboprophylaxis.

Percutaneous vertebroplasty in osteoporosis, myeloma and Langerhans' cell histiocytosis.

This review aims to assess the effectiveness of percutaneous vertebroplasty as a treatment for the severe refractory pain associated with vertebral fracture, in a group of patients with fractures secondary to either osteoporotic or neoplastic disease. A retrospective review of 20 patients treated with percutaneous vertebroplasty in Cork University Hospital up until March 2007 was carried out and a questionnaire was prepared and distributed. Prior to vertebroplasty, patients had been symptomatic with severe pain for a mean of 20.9 weeks. Of those thirteen whom replied to a postal questionnaire, 12 (92.3%) reported pain relief and this improvement occurred within 7 days in 9 (81.8%). This was associated with decreased analgesic requirements, as determined on chart review. Prior to the procedure only 5 (38.4%) were independently mobile and this figure rose to 10 (76.9%) afterwards, occurring within one week in the majority. Subjective outcomes were better in the group of patients with neoplasm-induced fractures.

Perinatal determinants of D-dimer levels in a cross-sectional study of low risk pregnant women.

BACKGROUND: To examine perinatal determinants of the antenatal levels of D-dimers. METHODS: Cross-sectional study of 760 low risk pregnant women recruited into five gestational groups. Variables examined in antenatal groups included maternal age, body mass index, parity, smoking, family history venous thromboembolism (VTE) and previous use of the oral contraceptive pill (OCP). Onset of labour and mode of delivery were also examined in the post-natal group. RESULTS: D-dimer levels in group 4 (38-40 + 6) were significantly lower in the women with a history of taking the OCP when compared to those that had not taken it in the past (P = 0.027). In the day 2 post-natal group, the median level of D-dimer was significantly higher in primparous when compared to multiparous women (P = 0.015). The median D-dimer levels were significantly lower in the elective Caesarean section group in comparison to spontaneous onset (P = 0.003) and induction of labour (P = 0.016). When the mode of delivery was examined, the median D-dimer levels were significantly lower in those that had an elective Caesarean section when compared to normal vaginal delivery (P = 0.008) and instrumental vaginal delivery (P = 0.007). Women post elective Caesarean section had a significantly lower D-dimer than those after emergency Caesarean section (P = 0.008). DISCUSSION: There are some significant differences in D-dimer levels when certain perinatal determinants are examined. This work is potentially beneficial to the future diagnosis of VTE in pregnancy as it supports previously published recommended D-dimer levels for the diagnosis of VTE in pregnancy.