Combined Spinal/Epidural Flashcards
What is the traditional method for performing a
combined spinal/epidural?
An epidural needle is placed in the epidural space. A spinal
needle is then passed through the epidural needle and into the
subarachnoid space. The spinal anesthetic is administered and
the spinal needle is withdrawn completely. The epidural
catheter is then threaded through the epidural needle and can
then be used to increase the duration of the neuraxial block
intraoperatively or used for postoperative analgesia.
Barash PG, Cullen BF, Stoelting RK, Cahalan MK, Stock MC,
Ortega R. Clinical Anesthesia. 7th ed. Philadelphia, PA:
Lippincott Williams and Wilkins; 2013: 915.
What is the advantage to performing a combined
spinal/epidural?
It provides the rapid onset and dense block of a spinal
anesthetic with the duration and flexible dosing provided by an
epidural catheter.
Barash PG, Cullen BF, Stoelting RK, Cahalan MK, Stock MC,
Ortega R. Clinical Anesthesia. 7th ed. Philadelphia, PA:
Lippincott Williams and Wilkins; 2013: 915.
How does the selection of the spinal needle for a
combined spinal/epidural affect the incidence of
postdural puncture headache?
The use of 24 to 27 gauge pencil-point needles (Whitacre,
Sprotte, or Gertie Marx) helps reduce the incidence of postdural
puncture headache.
Nagelhout JJ, Plaus KL. Nurse Anesthesia. 5th ed. St. Louis,
MO: Elsevier Saunders Company; 2014: 1085.
What is the appropriate spinal needle length for
performing a one-level, combined spinal/epidural
anesthetic?
One of the factors associated with a decreased success rate on
the spinal portion of the procedure is a spinal needle that is too
short. The spinal needle should be 7-15 millimeters longer than
the epidural needle.
Nagelhout JJ, Plaus KL. Nurse Anesthesia. 5th ed. St. Louis,
MO: Elsevier Saunders Company; 2014: 1096.
How does the use of intrathecal opioids in a
combined spinal/epidural affect the incidence of
postdural puncture headache?
The use of opioids has been shown to reduce the incidence of
postdural puncture headache in combined spinal/epidural
anesthesia.
Nagelhout JJ, Plaus KL. Nurse Anesthesia. 5th ed. St. Louis,
MO: Elsevier Saunders Company; 2014: 1097.
How does patient position affect the odds for
success when performing a combined
spinal/epidural anesthetic?
The odds for success are higher when the procedure is
performed with the patient in a sitting, rather than lateral
position. This is probably due to the higher hydrostatic pressure
in the subarachnoid space in the sitting position, which makes
the detection of CSF more likely.
Nagelhout JJ, Plaus KL. Nurse Anesthesia. 5th ed. St. Louis,
MO: Elsevier Saunders Company; 2014: 1097.
What factors are associated with an increased risk
that the epidural catheter could migrate into the
subarachnoid space after a combined
spinal/epidural?
Dural puncture with a 25-gauge needle does not increase the
risk, but puncture of the dura with an 18-gauge Tuohy needle
increases the risk that the epidural catheter could migrate into
the subarachnoid space. Other factors associated with an
increased risk include patient movement, undetected dural
puncture, and diffusion of the epidural dose into the
subarachnoid space.
Nagelhout JJ, Plaus KL. Nurse Anesthesia. 5th ed. St. Louis,
MO: Elsevier Saunders Company; 2014: 1096-1097.
When performing the epidural portion of a combined
spinal/epidural, should you use air or saline to
determine entry into the epidural space and why?
The epidural space should be identified with the use of air
because the use of saline may create a potential confusion
between saline and CSF.
Butterworth JF, Mackey DC, Wasnick JD. Morgan & Mikhail’s
Clinical Anesthesiology. 5th ed. New York, NY: McGraw-Hill;
2013: 854.
How does injection of local anesthetic into the
epidural catheter affect the spread of the spinal
anesthetic and why?
Injection of solution through the epidural catheter is known to
increase the spread of the spinal anesthetic. It is believed that
the increased volume injected into the epidural space
compresses the subarachnoid space, resulting in an increase in
pressure that ‘pushes’ the local anesthetic in the subarachnoid
space higher. Another cause is the leakage of local anesthetic
from the epidural space into the subarachnoid space via the
dural puncture made for the spinal anesthetic.
Nagelhout JJ, Plaus KL. Nurse Anesthesia. 5th ed. St. Louis,
MO: Elsevier Saunders Company; 2014: 1097
If you are performing an epidural anesthetic and
inadvertantly puncture the dura, can you convert the
epidural to a combination spinal/epidural?
Yes, this a common technique for dealing with inadvertant dural
puncture.
Wong, CA. Spinal and Epidural Anesthesia. New York:
McGraw-Hill; 2007: 298.
How is a two-level combined spinal/epidural
performed?
A two-level combined spinal/epidural is performed by first
placing the epidural catheter, then performing a spinal
anesthetic one or two interspaces below the epidural.
Nagelhout JJ, Plaus KL. Nurse Anesthesia. 5th ed. St. Louis,
MO: Elsevier Saunders Company; 2014: 1095.
What is the advantage of performing a two-level
combined spinal/epidural?
It allows the anesthesia provider the ability to test the function of
the epidural catheter prior to placing the spinal anesthetic.
Nagelhout JJ, Plaus KL. Nurse Anesthesia. 5th ed. St. Louis,
MO: Elsevier Saunders Company; 2014: 1095.
What are the disadvantages of performing a twolevel
combined spinal/epidural?
It can be difficult to distinguish between the epidural test dose
and CSF when performing the spinal anesthetic. CSF flow may
be hindered by the compression of the dural sac by the epidural
test dose. The epidural catheter can be cut by the spinal
needle. There is a risk of dural puncture with the epidural
catheter.
Nagelhout JJ, Plaus KL. Nurse Anesthesia. 5th ed. St. Louis,
MO: Elsevier Saunders Company; 2014: 1095.
What is a disadvantage of performing a continuous
spinal/epidural anesthetic?
It is asssociated with a high incidence of postdural puncture
headache.
Wong, CA. Spinal and Epidural Anesthesia. New York:
McGraw-Hill; 2007: 298.
