Eye surgeons need "working" knowledge of blood thinners: paper

By Megan Brooks

NEW YORK (Reuters Health) - For the ophthalmic surgeon, managing antiplatelet and anticoagulant treatment in patients undergoing elective surgery can be "challenging," note the authors of a new paper.

The ophthalmic surgeon "should have a working knowledge of the anticoagulant and antiplatelet treatments routinely used today and should carefully consider the risks and benefits of either continuing or stopping blood thinning therapy prior to surgery," Jonathan Norris, the corresponding author on the paper and consultant oculoplastic and ophthalmic surgeon at the Oxford Eye Hospital in the United Kingdom, told Reuters Health by email.

The availability of newer medications and the expanding use of antiplatelet and anticoagulant drugs has fueled a need for up-to-date guidance on the subject, Norris and his colleagues say.

They reviewed the literature and current UK national guidance on management of patients on antiplatelet and anticoagulant therapy in the context of eye surgery, reporting their findings April 1 in the British Journal of Ophthalmology.

Norris told Reuters Health, "Performing surgery on patients who are anticoagulated can result in excess bleeding, which may lead to complications such as sight loss. Stopping such treatments however, may conversely increase the risk of a heart attack, DVT or stroke. The safe management of blood thinning drugs at the time of surgery is therefore complex and based on a number of factors."

"The primary reason for this review was to educate and update eye surgeons and ophthalmic nurses on the latest antiplatelet/anticoagulant treatments available and to provide guidance on how best to manage these commonly prescribed drugs," Norris said.

In their review, the researchers found "relatively little evidence" on the risk of sight-threatening bleeding complications in patients undergoing ophthalmic procedures, particularly in patients using newer antiplatelet and anticoagulant medications.

Their paper provides a synopsis of what is known for common surgeries including surgery for cataracts, glaucoma and strabismus, vitreoretinal and oculoplastic surgery, and corneal surgery.

During preoperative assessment, attempts should be made to identify the risk factors that could have an impact on surgical success, the authors say.

Risk factors for intraoperative and postoperative hemorrhage include history of bleeding disorders or thromboembolic events; liver failure, renal failure or anemia; cardiac stent; uncontrolled hypertension; herbal treatments like feverfew, garlic, ginger, ginkgo and Asian ginseng; and family history of bleeding or clotting disorders.

Once surgery is planned, the decision to stop or continue antiplatelet or anticoagulant therapy is made based on the risks and benefits of each option, the authors say.

"If a decision to stop antiplatelet treatment is made, then in patients who do not have a coronary stent it is recommended that their aspirin be stopped 7-10 days preoperatively, to reduce the risk of bleeding," they say. Non-steroidal anti-inflammatory medications which act as reversible platelet inhibitors can be stopped 24 to 72 hours preoperatively.

"In patients who have a coronary stent, a discussion with the patient's cardiologist and an agreed management plan is mandatory in advance of surgery," they advise.

For patients on warfarin having elective ophthalmic surgery that requires temporary cessation of treatment, it is recommended that patients stop taking their warfarin five days preoperatively so that their international normalized ratio (INR) is near normal at the time of surgery. Warfarin then needs to be restarted 12 to 24 hours postoperatively, typically the evening after surgery, if hemostasis has successfully been achieved, the authors say.

As for the newer oral anticoagulants, for patients on dabigatran, renal function needs to be assessed to determine the best time to stop it. Rivaroxaban should be discontinued at least 24 hours before the surgical intervention and restarted as soon as possible afterward.

In patients using apixaban, the potential for surgical bleeding should be assessed. In moderate to high-risk patients, apixaban should be discontinued at least 48 hours prior to surgery. In low-risk patients, it should be stopped at least 24 hours prior to surgery. Apixaban should be restarted after the surgery as soon as possible, the authors say.

"With newer drugs available and rapidly changing indications, managing surgical patients on various antiplatelet and anticoagulant therapies is becoming increasingly complex. It is imperative that the ophthalmic surgeon is familiar with issues surrounding modern day antiplatelet and anticoagulant treatments," the authors conclude.

SOURCE: http://bit.ly/1r53pbD

Br J Ophthalmol 2014.

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