Can Direct Spinal Cord Injury Occur Without Paresthesia A Report of Delayed Spinal Cord Injury After

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Can Direct Spinal Cord Injury Occur Without
Paresthesia? A Report of Delayed Spinal Cord
Injury After Epidural Placement in an Awake
PatientAnesth Analg 200510112124

• Ban C. H. Tsui, MD, MSc, and Kevin Armstrong, MD
• ?????????????
• R2 ???

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Introduction

• Reports of spinal cord injury occurring while
  performing epidural anesthesia in unconscious or
  awake patients
• the safety of performing epidural anesthesia in
  awake versus unconscious patients
• Will the conscious patient always report a
  paresthesia in response to spinal cord or nerve
  root trauma?

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Case Report

• An 81-yr-old male (69 kg)
• Whipple resection for pancreatic cancer
• physical and neurological examinations were
  unremarkable
• T8-9 interspace with the patient awake
• Right paramedian epidura 17-gauge Tuohy needle
• loss of resistance, but dura puncture

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Case Report

• A second single pass attempt was successfully
  made one interspace lower and a soft-tipped
  epidural catheter was threaded easily into the
  epidural space
• there was no pain or discomfort during the
  procedure. No blood or CSF was returned through
  the catheter
• 2 5-mL boluses of 0.125 bupivacaine plus 5 µg/mL
  of fentanyl were given and a 12 mL/h infusion of
  the same solution

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Case Report

• 80/50 mm Hg at 75 min and 75/45 mm Hg at 150 min
  postinduction. Both episodes responded readily to
  ephedrine (5 and 10 mg respectively)
• Estimated blood loss was 900 mL, which was
  replaced with 2000 mL of Ringers lactate
  solution and 1000 mL of Pentaspan
• Surgery lasted approximately 4 h and extubated in
  the operating room. admitted to the intensive
  care unit in stable condition for postoperative
  monitoring

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Case Report

• POD 1 obtunded but he moved all four limbs
  spontaneously, so 2 µg/mL of fentanyl instead
• POD 2 drowsy, 12 mL/h to 9 mL/h.
• POD 3 more alert, but difficulty when mobilizing
  for any activity, 6mL/h
• POD 4 infusion was stopped. NE revealed little
  or no movement (0/5) and no sensation to pinprick
  in the right leg. The epidural catheter was
  immediately removed intact

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Case Report

• POD 5 Spinal cord edema, a high T2 signal
  intensity on MRI, compatible with direct trauma
  was noted from the mid T9 to the mid T10
  vertebral body

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Case Report

• a posterior extradural fluid collection from the
  T8-9 disk level extending inferior to the T11
  vertebral body consistent with a hematoma was
  present

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Case Report

• an emergency laminectomy and evacuation of the
  hematoma 7 h after the MRI results
• Under direct surgical examination, the hematoma
  did not appear to cause significant compression
• Postlaminectomy, motor and sensory function was
  still profoundly depresse
• After 8 wk, was able to bear weight on his right
  leg
• At 12 wk, could ambulate with a walker but with
  impaired proprioception

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Discussion

• Spinal cord damage needle or catheter trauma,
  local anesthetic toxicity, epidural hematoma,
  ischemia from an arterial injury, or severe
  hypotension.
• MRI did not suggest significant compression of
  the spinal cord, a fact confirmed at laminectomy
• clinical sign of spinal cord ischemia is normally
  bilateral paresis of the legs
• it is highly unlikely that drug toxicity would
  account for this unilateral right side spinal
  cord edema

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Discussion

• This rapid infusion rate would make intrathecal
  catheter placement very unlikely, as there was no
  sign of a total spinal
• a soft catheter was used further reduces the
  likelihood of direct catheter trauma
• Edema mainly localized on the right side of the
  spinal cord, and epidural needle placement while
  using a right-sided paramedian approach.
• So spinal cord needle puncture highly suspected

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Discussion
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Discussion

• whether paresthesia is a reliable sign of spinal
  cord encroachment?
• Paresthesia associated with spinal cord injury
  can occur at the time of needle placement but it
  also has been reported to develop only at the
  time of injection or secondary to irritation,
  edema, or hematoma
• pain is more common in extraaxial lesions
  affecting the nerve roots, but no pain receptors
  within the spinal cord itself (or the brain),
  intraaxial lesions may be painless

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Discussion

• In addition, pain reported from dural puncture is
  rare in clinical practice
• A delayed diagnosis as a result of human error,
  lack of vigorous neurological monitoring, and
  uncontrollable environmental conditions
  contributed to the extent of the damage
• vigorous postoperative neurological monitoring
  should be implemented in all patients receiving
  neuraxial analgesia

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Discussion

• Preoperative review of diagnostic imaging of the
  vertebral column may be helpful

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Summery

• we should not simply assume paresthesia will
  always occur and be reported if a needle
  encroaches upon the spinal cord
• there is still no clear evidence that direct
  thoracic epidural placement can be performed
  without risk in either awake or anesthetized
  patients