• DVT-PE chemoprophylaxis-Neurosurgical Issues.

    21 September at 16:17 from atlas

    Date: 26th January 2012

    VTE Prophylaxis in Neurosurgery - Rationale, Benefits, Risks & Guidelines

    A major concern exists in the utilisation of chemoprophylactic agents such as heparin,clexaine etc in Neurosurgical patients,which may actually cause morbidity & death, rather than prevent them.In special ares of surgery , such as Neurosurgery, and Cardiothoracic Surgery,haemorrhage can have particularly devastating complications such as death, quadriplegia, paraplegia etc.There is a wide divergence of opinions on the general use of VTE Prophylaxis amongst Neurosurgeons , with a range of practices including nil, hydration and early mobilisation, mechanical devices such as GCS(Graduated Compression Stockings)or TEDS(Thrombo-Embolic Device Stockings) and SCD (Sequential Compression Devices) ,and Chemoprophylactic Agents (heparin, clexaine etc).Furthermore, there is lack of consensus as to the optimal timing for use of Chemoprophylactic Agents, if prescribed.Some Neurosurgeons administer such agents pre-operatively, others within 12-24 hours of surgery and others only if the patient will have prolonged immobilisation due to pain,paralysis, complications requiring prolonged immobilisation , e.g. dural tear , requirement CSF drainage etc.

    The isssue in Neurosurgical patients relates to an analysis of the frequency&consequences of DVT-PE ,risk stratification and selecting the most appropriate form of prophylaxis, with specific attention to the risks particular to Neurosurgical patients (enclosed spinal cord and brain), if a haematoma was precipitated by chemoprophylaxis.In many cases the Neurosurgeon finds him/herself in a difficault situation- defending a quadriplegia for administering heparin versus a fatal PE and not administering heparin-both consequences are grave to the patient.There is also no shortage of critics and "experts' after the event, but little definitive guidance by agencies in the decision making process.A neurosurgeon (and Cardio-thoracic surgeon) do all possible to achieve absolute haemostasis during surgery because the consequences peculiar to Neurosurgery, and Cardio-thoracic surgery demand this.Such surgeons do not want a patient on heparin, during or after surgery when there is little, if any Class A evidence that there is a risk of DVT-PE which exceeds the consequences of a heparin precipitated haematoma, or, when there is little, if any Class A evidence that administering heparin actually reduces the actual risk of a significant DVT-PE.

    Reference is made to the Queensland Health Quality and Complaints Commission (HQCC) Healthcare Standards v2.0 (effective 1 July 2010).The HQCC requires that "all adult patients are assessed for their risk of VTE, their bleeding risk and receive thromboprophylaxis where appropriate and not contra-indicated".The Commission recognises that "bleeding is a major complication arising from pharmacological thromboprophylaxis, and is known to be a side-effect of anti-coagulants".Further, the Commission recommends an assessment for patients "risk of bleeding prior to choosing thromboprophylaxis, either pharmacological or mechanical or both".The Commission "requires clinical leaders to demonstrate support and quality improvement in the reduction of the risk of VTE.

    The Commission refers to three resources in their Standard:(1)National Institute of Health and Clinical Excellence, (2) National Clinical Guideline Centre.Venous Thromboembolism:reducing the risk .London:National Clinical Guidelines Centre-Acute and Chronic Conditions 2009, (3) Geerts,W et al.Prevention of venous Thrombo-embolism;American College of Chest Physicians' evidence-based clinical practice guidelines 8th edition.Chest. 2008.133:381S-453S(.I add (4) NSW Health Clinical Practice Guidelines for Pre-operative Management of the Neurosurgical Patient.November 2007.)

    (1) NHMRC Guidelines: Neurosurgery represents a high-risk of VTE however, the consequences of bleeding can be severe following Neurosurgery...further warns that pharmacological thromboprophylaxis should be used 'with caution in Neurosurgery patients depending on the risk of VTE and bleeding"...'mechanical methods may be an appropriate alternative".The NHMRC make Grade A recommendations for IPPC following neurosurgery until the patient is fully mobile and a GPP recommendation to use pharmacological methods "with extreme caution" following surgery, due to the high risk of bleeding.They advise that where pharmacological methods are 'appropriate' and "not contraindicated' , use of LMWH or UF heparin.MHMRC have Grade C recommendation for GCS following Neurosurgery(alone or with pharmacological measures).

    (2) National Clinical Guidelines Centre 2009 (pages 1-10 7 277-288) : offer VTE prophylaxis to cranial or Spinal surgery patients who are aseesed to be at increased risk of VTE...(LIST includes ; total anaesthetic & surgical time 90 minutes,expected reduction in mobility, one or more of-active cancer/age 60 years/dehydration/BMI 30 kg/m2/Previous personal history or FH VTE/oestrogen therapy/pregnancy& post-partum etc). They recommend start mechanical VTE prophylaxis on admission -choose any ONE of ; anti-embolism stockings, foot impulse devices,IPCD ; & continue mechanical prophylaxis until patient mobile, AND add pharmacological VTE prophylaxis to patients with 'low risk of major bleeding, taking into account individual patient factors & according to clinical judgement..continue until patient mobile...generally 5-7 days.

    (3) Review of American College of Chest Physicians'Evidence-based Clinical Practice Guidelines.(William Geerts et al 2008). this is a 70 page document and section 4.0 Neurosurgery on pages 19-20 recommends for all patients undergoing major Neurosurgery that thromboprophylaxis be used routinely with optimal use of IPCs.Acceptable alternatives to IPC are post-operative LMWH or LDUH & for patients who have a "particularly high thrombosis risk", that a mechanical method (i.e. GCS and/or IPC) be COMBINED with a pharmacological method (i.e. post-operative LMWH or LDUH).

    CONCLUSIONS & SUGGESTED APPROPRIATE & SAFE NEUROSURGICAL VTE PROPHYLAXIS.

    (1)With reference to the three aforementioned authorities deemed as relevant by the HQCC, I propose that there is no definite evidence-based requirement for chemoprophylaxis in ALL Neurosurgical patients.There appears to be a uniform recommendation for the use of mechanical measures in most, if not all, Neurosurgical patients AND that the adjuvant use of chemoprophylaxis be used in patients described as being at "high risk for VTE".The authorities all caution that chemprophylaxis is 'high risk' and "must be used with extreme caution".All agencies delegate decision making regarding the specific risk/benefit assessment of chemoprophylaxis to the neurosurgeon- which is reasonable-providing ofcourse that advice is not later rescinded by the HQCC. In the event of death ,or quadriplegia from heparin induced bleeding, in a patient that the Neurosurgeon considered the use of heparin etc appropriate, or ,conversely in a death due to VTE-PE in a patient not given heparin , again a decision which the HQCC (by virtue of the contents of the guidelines they have recommended as relevant) DELEGATED to the neurosurgeon (because of the risks of bleeding, need to use with'extreme caution' etc)should be RESPECTED.The Neurosurgeon often feels "dammed if he/she prescribes heparin/clexaine , and dammed if he/she doesn't'-and relies on what are clearly "Guidelines" by the HQCC gleaned from other authors, listed in their publication, and reviewed comprehesively above.

    (2) There are diverse and well-argued practices in this difficult neurosurgical area around the world.Death, quadriplegia and paraplegia do occur after heparin etc in Neurosurgey , as do fatal PEs in cases not prescribed such agents-both scenarios are devastating to Neurosurgeon, Nurses and patients/families.

    (3) I propose& practise the following protocol for VTE Prophylaxis in Cranial& Spinal Neurosurgery.


    " 1.Detailed history in respect of bleeding, VTE and medications review.
    2.The use of GCS AND SCDs in ALL patients undergoing Cranial/Spinal surgery providing there are no contra-indications e.g. peripheral neuropathy, peripheral vascular disease, venous ulceration etc.
    3.Prevent dehydration with IV fluids and anti-emetics in all patients.
    4.Plan early (ambulation within 24 hours) using appropriate analgesia, nursing& physiotherpy assistance and walking devices ALONG with hourly calf exercises and incentive spirometry THEN removal of SCDs.
    5.The adjuvant use of SC Heparin, e.g.. 5000 U bd commencing on the evening of surgery & continuing during hospitalisation in patients that I assess as being HIGH-RISK of VTE including:previous DVT or PE, FH of DVt or PE, Obesity BMI 30 kg/m2, active malignancy or infection, previous extensive pelvic surgery, known varicose vein disesae with phlebitis, patients on HRT or Oestrogen OCP & patients with pre-morbid neurological deficit & anticipated OR unexpected requirement for prolonged immobilisation."

    "I ADVISE THAT...

    THE DECISION FOR THE USE OF CHEMO-PROPHYLAXIS SHALL BE AT THE DISCRETION OF THE NEUROSURGEON CONSIDERING THE INDIVIDUAL RISK& CONSEQUENCE OF INTRA OR POST-OPERATIVE BLEEDING WHICH COULD CAUSE DEATH, QUADRIPLEGIA OR PARAPLEGIA AND WEIGHING THIS RISK UP AGAINST THE POTENTIAL BENEFITS IN REDUCTION OF VTE(& CONSEQUENCES OF SAME) , WHEN OTHER MECHANICAL &MOBILISATION ETC MEASURES ARE PLANNED TO BE ADOPTED IN ANY EVENT..."

    I believe this approach adequately balances the best measures to minimise VTE AND address the extreme caution & risk associated with chemoprophylaxis in Neurosurgical patients.