Does preoperative DVT chemoprophylaxis in spinal surgery affect the incidence of thromboembolic complications and spinal epidural hematomas?
BACKGROUND
Deep venous thrombosis (DVT) and pulmonary embolus (PE) remain common surgical complications, often affecting patients without any prior warning. Postoperative spinal epidural hematomas (SEH) may have a devastating impact on a patient's recovery from a routine procedure. The effect of preoperative DVT prophylaxis administration on elective spinal patients has not previously been studied.


METHODS
Retrospective cohort analysis.


OBJECTIVE
To correlate the incidence of preoperative DVT prophylaxis administration and the rate of postoperative DVT, PE, and SEH after elective spinal surgery.


BACKGROUND
Earlier studies have shown a postoperative DVT rate in elective spinal patients of between 0.3% and 31%, a PE rate of 0.2% to 0.9%, and a SEH rate of approximately 0.1%.


METHODS
About 3870 patient notes, from 2004 to 2008 elective spinal procedures, were reviewed. DVT, PE, and SEH rates were compared between those patients receiving and not receiving preoperative DVT prophylaxis.


RESULTS
The 36.9% of patients received preoperative DVT prophylaxis, and 19 patients suffered and DVT and/or PE. Nine of these had received preoperative prophylaxis, giving an odds ratio of 0.91. Sixteen patients suffered a SEH, and this gave an odds ratio of 1.33. The SEH's presented with a median postoperative time of 4 days.


CONCLUSIONS
Preoperative DVT prophylaxis does not influence the rate of postoperative DVT or PE among elective spinal patients. It probably does not influence SEH rate, and it is noted that SEH may present quite late, in contrast to currently accepted time courses.
University of Calgary Spine Program, Foothills Medical Centre, Canada.
John Edward
JE
Cunningham
Ganesh
G
Swamy
Ken C
KC
Thomas
D000368:Aged; D000369:Aged, 80 and over; D018890:Chemoprevention / Q000379:methods; D015331:Cohort Studies; D017558:Elective Surgical Procedures / Q000009:adverse effects; D005260:Female; D046748:Hematoma, Epidural, Spinal / Q000453:epidemiology* / Q000517:prevention & control; D006493:Heparin / Q000008:administration & dosage*; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D011183:Postoperative Complications / Q000453:epidemiology* / Q000517:prevention & control; D011300:Preoperative Care / Q000379:methods*; D011655:Pulmonary Embolism / Q000453:epidemiology* / Q000517:prevention & control; D012189:Retrospective Studies; D013923:Thromboembolism / Q000453:epidemiology / Q000517:prevention & control; D020246:Venous Thrombosis / Q000453:epidemiology* / Q000517:prevention & control
D006493:Heparin