From the Research
Treatment for deep vein thrombosis (DVT) should be initiated in a patient with a possible bowel obstruction undergoing sigmoidoscopy, but with careful consideration of the bleeding risk. The standard approach would be to start with therapeutic anticoagulation using low molecular weight heparin (LMWH) such as enoxaparin 1 mg/kg twice daily or 1.5 mg/kg once daily, or unfractionated heparin with an initial bolus of 80 units/kg followed by continuous infusion at 18 units/kg/hour, adjusted to maintain aPTT at 1.5-2.5 times normal 1. Unfractionated heparin may be preferred in this scenario due to its shorter half-life and reversibility if bleeding occurs during the sigmoidoscopy. The timing of anticoagulation should be coordinated with the procedure - ideally holding the dose 4-6 hours before sigmoidoscopy and resuming 12-24 hours after, depending on the findings and interventions performed. Some key points to consider in the management of such patients include:
- The risk of bowel obstruction and the need for urgent surgery, as indicated by signs such as abdominal pain, distension, and tenderness 2
- The potential for anticoagulation to increase the risk of bleeding, particularly in patients with a history of gastrointestinal surgery or disease 3
- The importance of early initiation of anticoagulation in patients with DVT, to minimize the risk of complications such as pulmonary embolism 4 If the bowel obstruction is confirmed and surgical intervention is needed, an inferior vena cava (IVC) filter might be considered as a temporary measure to prevent pulmonary embolism while anticoagulation is contraindicated. This approach balances the need to treat the potentially life-threatening DVT while minimizing bleeding risk during diagnostic and therapeutic procedures for the bowel obstruction. It is also important to note that the use of direct-acting oral anticoagulants (DOACs) may be affected by major gastrointestinal tract surgery, and their efficacy and safety in this context are not well established 1.