Daily vs twice daily enoxaparin in the prevention of venous thromboembolic disorders during rehabilitation following acute spinal cord injury.

BACKGROUND: Subcutaneous administration of low molecular weight heparin (eg, enoxaparin) has been shown to be safe and effective in the prevention of acute venous thromboembolic (TE) disease following acute spinal cord injury (SCI) in the rehabilitation setting. However, emerging evidence suggests that different dosing strategies may be equivalent. OBJECTIVE: To determine whether subcutaneous enoxaparin, 40 mg once daily, when compared with subcutaneous enoxaparin, 30 mg twice daily, is equally safe and effective in the prevention of venous TE disease in patients with SCI. DESIGN: Retrospective chart review. SETTING: A freestanding, inpatient, acute, rehabilitation hospital. PATIENTS: One hundred and twenty-nine patients admitted from June 2000 through June 2002 for inpatient rehabilitation following an acute SCI who received either enoxaparin, 40 mg once daily, or enoxaparin, 30 mg twice daily, for prophylaxis for TE disease. RESULTS: Equivalent prophylaxis efficacy was seen in both enoxaparin groups. Symptomatic venous thromboembolism did not differ, with deep vein thromboses occurring in 1 of 49 (2.0%) patients receiving twice-daily enoxaparin, and 1 of 80 (1.25%) patients receiving once-daily enoxaparin (chi2 = 0.125, NS). Pulmonary embolism was seen in 1 of 49 (2.0%) patients treated with twice-daily enoxaparin and in none of the patients in the once-daily group (chi2 = 1.64, NS). Bleeding complications also did not differ between the 2 treatment groups; these were observed in 2 of 49 (4.1%) patients receiving twice-daily enoxaparin and in 5 of 80 (6.3%) patients receiving once-daily enoxaparin (chi2 = 0.228, NS). CONCLUSION: Subcutaneous enoxaparin administered once or twice daily is equally effective for the prevention of venous TE disease. Both dosing strategies are associated with a low incidence of bleeding in patients with SCI who are undergoing rehabilitation.

Development of a sexually dimorphic neuromuscular system in male rats after spinal transection: morphologic changes and implications for estrogen sites of action.

The lumbar spinal cord of rats contains the sexually dimorphic, steroid-sensitive spinal nucleus of the bulbocavernosus (SNB). In male rats, SNB motoneurons exhibit a biphasic pattern of dendritic growth, having an initial period of exuberant growth followed by a period of retraction to mature lengths by 7 weeks of age. This growth is steroid dependent: dendrites fail to grow after castration, but growth is supported in castrates treated with estradiol. In this experiment, we examined whether supraspinal afferent input by means of descending spinal tracts to the SNB was involved in the normal postnatal development of SNB motoneurons, and whether the effect of estradiol on SNB dendritic growth could be explained by an indirect action of estradiol on supraspinal afferents. Motoneuron morphology was assessed in normal males, early- or late-postnatally transected males, castrated males left untreated or treated with estradiol, and transected castrates treated with estradiol. SNB motoneurons were retrogradely labeled with cholera toxin-horseradish peroxidase during both the growth and retraction phases of dendritic development and reconstructed in three dimensions. The removal of supraspinal afferents resulted in extremely local effects within the developing SNB arbor, as well as transient alterations in somal growth. Furthermore, spinal transection did not block the trophic effect of estradiol on supporting SNB dendritic growth, indicating that estrogens do not act by means of supraspinal input to support SNB motoneuron development.