dxy

We continue our discussion of the guidelines for the performance of neuraxial anesthesia and analgesia in anticoagulated patients. Today we will be discussing the risks involved in the performance of a regional anesthetic in patients with impaired coagulation.
1.  What is the big deal about neuraxial anesthesia and anticoagulation? If it is safe to perform the surgery, then it must be safe to perform a regional anesthetic!
2.  What is the typical presentation of a spinal hematoma?
3.  How do you diagnose a spinal hematoma?
4.  What is the treatment of choice for a spinal hematoma?
1.神经阻滞和抗凝药之间关系有多大？如果实施手术时安全的，是否意味着区域阻滞也必然是安全的？
2.椎管内血肿的典型表现是什么？
3.如何诊断椎管内血肿？
4.椎管内血肿的治疗措施有哪些？

[每周一问]NO.9参考答案
1.神经阻滞和抗凝药之间关系有多大？如果实施手术时安全的，是否意味着区域阻滞也必然是安全的？
并非必然如此！在没有停止使用抗凝药的情况下安全实施手术和外周神经阻滞只占极少部分。INR<1.5对于安全的手术是可行的[1]。外科出血时可见的，可以通过吸引，并在必要时给与输血。如果患者持续出血，可以通过给与新鲜冰冻血浆逆转抗凝药的作用。
硬膜外静脉破裂可能导致硬膜外血肿发生。血肿可能压迫脊髓产生占位性病变，虽然神经阻滞后出现椎管内血肿非常罕见（硬膜外麻醉1:150,000，蛛网膜下腔麻醉后1:220,000），但是很多病例（在一报道中为68%）出现凝血功能受损[2]。

2.椎管内血肿的典型表现是什么？
如果出现严重的背痛，同时伴有下肢肌张力减弱与感觉减退，应该怀疑椎管内血肿。其代表患者存在生命威胁，并应该立即得到救治。

3.如何诊断椎管内血肿？
磁共振成像通过对脊髓病变进行评估，是怀疑有椎管内血肿患者的诊断性选择之一。MRI对于该情况非常敏感，也是特有的可无创显示脊髓影像及周围结构如CSF、灰白质结构及邻近韧带的技术。马尾及腰区的神经根也可以得到评估[3]。

4.椎管内血肿的治疗措施有哪些？
椎管内血肿诊断明确后，必须立即进行椎板减压切除术，因为手术时间耽误可导致不可逆的神经损伤。如果在第一症状出现后8小时后未行椎板减压术，椎管内血肿可导致严重的破坏性结果，如下肢的弛缓性麻痹。

[每周一问]NO.9之英文参考答案
What is the big deal about neuraxial anesthesia and anticoagulation? If it is safe to perform the surgery, then it must be safe to perform a regional anesthetic!
Not necessarily! Relatively minor surgical and peripheral nerve procedures can be safely performed without discontinuing the anticoagulant regimen. An INR value of < 1.5 is acceptable for the safe performance of surgery (1). Surgical bleeding is visible, could be suctioned and the patient may be transfused if necessary. If the patient continues to bleed, reversal of the anticoagulation may be attempted with fresh frozen plasma.
The presence of blood from a ruptured epidural vein in the epidural space could lead to a spinal hematoma. This hematoma could produce a mass occupying lesion with cord compression. Although spinal hematoma after a neuraxial blockade is very unusual (1:150,000 after epidural anesthesia and 1:220,000 after spinal anesthesia), most cases (68% in one report) have resulted in patients with impaired coagulation (2).

What is the typical presentation of a spinal hematoma?
A spinal hematoma should be suspected if severe backache appears in combination with weakness and decreased sensation of the lower extremities. It represents a life threatening emergency and the patient should be evaluated immediately.

How do you diagnose a spinal hematoma?
Magnetic resonance imaging is the diagnostic test of choice in patients with a suspected spinal hematoma by allowing the evaluation of spinal cord processes. MRI is very sensitive in this regard and is also unique in its inherent noninvasive ability to image the spinal cord and surrounding structures such as CSF, dura, and adjacent ligaments. The cauda equina and existing nerve roots in the lumbar region can also be assessed (3).

What is the treatment of choice for a spinal hematoma?
Immediate decompression laminectomy is the treatment that must be used in the presence of a spinal hematoma because irreversible neurologic deficit can result from delaying surgery. A spinal hematoma could lead to severe devastating results, such as a lower extremity flaccid paralysis, if the laminectomy is not performed within 8 hours of the first symptom presentation.
Question Author: David Hepner, MD, Department of Anesthesiology, Perioperative and Pain Medicine, Brigham and Women's Hospital, Harvard Medical School
References:
1.  Kearon C, Hirsh J. Management of anticoagulation before and after elective surgery. NEJM 1997:1506-11.
2.  Vandermeulen EP, Van Aken H, Vermylen J. Anticoagulants and spinal-epidural anesthesia. Anesth Analg 1994;79:1165-77.
3.  Goetz CG, Pappert EJ. Textbook of Clinical Neurology, 1st ed. 1999, W. B. Saunders Company.
Site Editor: Stephen B. Corn, M.D. and B. Scott Segal, M.D.
Department of Anesthesia, Harvard Medical School

本版发展，我们携手；专业进步；你我共荣