Correlation of missed doses of enoxaparin with increased incidence of deep vein thrombosis in trauma and general surgery patients.

Louis SG, Sato M, Geraci T, Anderson R, Cho SD, Van PY, Barton JS, Riha GM, Underwood S, Differding J, Watters JM, Schreiber MA.

 JAMA Surg. 2014 Apr;149(4):365-70.

Data were prospectively collected among 202 trauma and general surgery patients admitted to a level I trauma center.

The overall incidence of DVT was 15.8%.
 In total, 58.9% of patients missed at least 1 dose of enoxaparin. 
The DVTs occurred in 23.5% of patients who missed at least 1 dose and in 4.8% of patients who did not (P < .01). 
On univariate analysis, the need for mechanical ventilation (71.8% vs 44.1%), the performance of more than 1 operation (59.3% vs 40.0%), and male sex (75% vs 56%) were associated with DVT formation (P < .05 for all). 
A bivariate logistic regression was then performed, which revealed age 50 years or older and interrupted enoxaparin therapy as the only independent risk factors for DVT formation. 
The DVT rate did not differ between trauma and general surgery populations or in patients receiving once-daily vs twice-daily dosing regimens.

Interrupted enoxaparin therapy and age 50 years or older are associated with DVT formation among trauma and general surgery patients. 
Missed doses occur commonly and are the only identified risk factor for DVT that can be ameliorated by physicians. 
Efforts to minimize interrupted enoxaparin prophylaxis in patients at risk for DVT should be optimized.