Venous Thromboembolism Prophylaxis in Low Body Weight Critically Ill Patients

OBJECTIVE

To compare bleeding and thromboembolic events in low body weight patients receiving reduced-dose venous thromboembolism (VTE) prophylaxis versus standard-dose VTE prophylaxis.

DESIGN

Multicenter, retrospective, cohort study.

SETTING

Five Ascension Health Hospitals.

PATIENTS

Adult, critically ill, low body weight (≤50 kg) patients who received either reduced-dose VTE prophylaxis (n = 140) or standard-dose VTE prophylaxis (n = 279) for at least 48 h.

INTERVENTION

Reduced-dose prophylaxis (enoxaparin 30 mg daily or heparin 5000 units every 12 h subcutaneously) or standard-dose prophylaxis (enoxaparin 40 mg daily, enoxaparin 30 mg every 12 h, or heparin 5000 units every 8 h subcutaneously).

MEASUREMENTS AND MAIN RESULTS

A total of 419 patients were included with a mean weight of 45.1 ± 4.2 kg in the standard-dose group and 44.0 ± 5.1 kg in the reduced-dose prophylaxis group (P = .02). The primary endpoint, composite bleeding, was significantly lower in patients receiving reduced-dose prophylaxis (5% vs 12.5%, P = .02). After adjusting for confounding factors, results remained consistent demonstrating reduced composite bleeding with reduced-dose prophylaxis (odds ratio: 0.36, 95% confidence interval: 0.14-0.96). Major bleeding events occurred in 3.6% of reduced-dose patients compared with 8.6% in standard-dose patients (P = .056). Clinically relevant nonmajor bleeding (5.4% vs 2.9%, P = .24) and VTE (2.2% vs 0%, P = .08) events were similar between groups.

CONCLUSIONS

A reduced-dose VTE prophylaxis strategy in low body weight, critically ill patients was associated with a lower risk of composite bleeding and similar rate of thromboembolism.

Is it time to reassess the risk for the growth-retarded fetus with normal Doppler velocimetry of the umbilical artery?

OBJECTIVE

Previous studies demonstrate an association between abnormal umbilical artery Doppler velocimetry and the birth of a small-for-gestational-age infant and between abnormal result and adverse neonatal outcome. The hypothesis is that preterm growth-retarded infants with normal antenatal velocimetry have outcomes similar to other preterm infants, whereas preterm small-for-gestational-age infants with abnormal Doppler results define a subgroup with increased morbidity.

STUDY DESIGN

For 100 live-born infants, at risk for fetal growth retardation and undergoing antenatal Doppler and targeted ultrasonographic examinations, we assessed a number of complete neonatal outcome parameters.

RESULTS

Ten neonatal deaths occurred in the study population, seven with abnormal Doppler results and three with normal Doppler results. Of the 90 surviving infants, gestational age at delivery was not different between the Doppler normal and abnormal neonates, whereas birth weight (1714 gm vs 1379 gm) was higher in the Doppler normal group (p = 0.006). The presence of intraventricular hemorrhage (20% vs 6%) was higher in the abnormal group (p = 0.05). Abnormal Doppler results defined an infant group destined for prolonged hospitalization, mean intensive care days (21 vs 9), and special care nursery days (25 vs 9). Thirty-eight percent of small-for-gestational-age babies had a normal Doppler result. Analysis of variance indicated small-for-gestational-age infants with abnormal Doppler results (n = 20) had a mean intensive care unit stay of 31 days, significantly different (p = 0.005) from small-for-gestational-age infants with normal Doppler results (n = 14), non-small-for-gestational-age infants with abnormal results (n = 21), and non-small-for-gestational-age infants with normal results (n = 35) whose mean intensive care unit stays were 14, 12, and 7 days, respectively. Gestational age at delivery (33.0 weeks) was not different among these groupings, not accounting for the observed differences.

CONCLUSION

Normal antenatal velocimetry defines a distinct subgroup of preterm small-for-gestational-age infants at less risk for prolonged hospitalization compared with those with abnormal velocimetry.