- Lumbar technique) Operations below the umbilicus, such as hernia repairs, cesarean section, gynecologic or urologic procedures, and any lower extremity surgeries
- Thoracic technique) Operations on the chest and upper abdomen
- Labor analgesia and anesthesia for instrument-assisted deliveries
- Analgesia for trauma, such as rib fractures, flail chest, lower extremity trauma
Absolute Contraindications
- Patient refusal
- Uncorrected hypovolemia
- Antiplatelet dysfunction or therapy except aspirin
- HELLP (hemolysis, elevated liver enzymes, and low platelet count) syndrome
- Idiopathic thrombocytopenic purpura (ITP), thrombotic thrombocytopenic purpura (TTP)
- Prophylactic low molecular weight heparin (LMWH)–12 hours
- Therapeutic LMWH–24 hours
- Coumadin–5 days or a normal prothrombin/international normalized ratio (PT/INR)
- Stigmata of anticoagulation
- Petechiae, bleeding from IV site, bruising
- Any pathologic anticoagulated state
- Localized skin or soft tissue infection
- Intracranial hypertension
Relative Contraindications
(Relative contraindications may be overlooked in cases in which the benefits of analgesia via a lumbar epidural outweigh the risks associated with its placement and use.)
- Certain valvular or congenital heart disease (e.g. aortic stenosis, or tetralogy of Fallot)
- Severe hypertrophic cardiomyopathy
- Previous back surgery, back pain, or instrumentation
- Severe spinal or spinal cord deformity
- Platelet count <100,000 except in:
- Severe cardiovascular disease
Presence of neurologic disease such as multiple sclerosis or infectious disease such as HIV without central nervous system involvement is often cited as an absolute contraindication to epidural or spinal analgesia, but the prevailing evidence is that neuraxial anesthesia and analgesia can be safely delivered in such circumstances.
- Sterile gloves, gown, cap, and eye protection
- Epidural kit
- Small (3-5 mL) syringe for local anesthetic for skin infiltration with small (25- or 30-gauge) needle
- 22- and 19-gauge needles for deep, local anesthetic infiltration
- 1% Lidocaine for infiltration
- 18-gauge Tuohy needle with stylet—a large-bore needle with a rounded end. The cutting bevel is curved off to one side, allowing a catheter to be threaded through the needle to exit in an arc rather than straight out of the tip. Commonly used for epidural catheter placement but may also be used to place catheters into the subarachnoid space and to allow introduction of the spinal needle into the subarachnoid space for CSEA.
- Slip syringe for loss of resistance
- Sterile saline (for syringe)
- 24-gauge, 124-mm pencil-point spinal needle
- Spinal needle must be long enough to emerge through tip of Tuohy needle.
- Quincke-Babcock needle—the “standard” spinal needle with a sharp point and cutting bevel. This needle has been used less frequently, due to a higher incidence of post–dural puncture headache believed to result from cutting of dural fibers by the cutting bevel and resulting increased cerebrospinal fluid (CSF) leak.
- Whitacre and Sprotte needles—“pencil-point” needles, have a rounded noncutting bevel, with a solid tip and the opening of the needle to the side about 2 mm proximal to the tip. They are associated with a better “feel” of the resistance of the subcutaneous tissue and have a low incidence of post–dural puncture headache.
- Intrathecal dose of opioid with or without local anesthetic
- Anesthetic or analgesic for subarachnoid injection.
- Epidural catheter with Luer-Lok connector
The spinal cord reaches from the foramen magnum to the L1-L2 spine. The epidural space extends down to the sacral spine, surrounding the dura mater. The lumbar spine can be palpated using the iliac crest as a landmark for the L4 spine. Between the skin and the epidural spaces are three ligaments: the supraspinous ligament that connects lumbar spinous processes, the interspinous ligament between the bodies of the spinous processes, and the ligamentum flavum that surrounds the epidural space. At each level the space is framed by the ligamentum flavum, the posterior longitudinal ligament (anterior to the dura), and vertebral pedicles. The epidural space consists mostly of adipose, connective tissue, and blood vessels. Also within the epidural space there is a connective tissue called the plica mediana dorsalis, which may or may not be involved with unilateral or “patchy” epidural blocks.
Anatomic landmarks most important to performance of CSEA anesthesia are the iliac crests, the midline of the back, and the vertebral spinous processes. Palpation of the midline of the back identifies the spinous processes and vertebral interspaces in most patients but may be difficult in obese patients. Even in obese patients, however, C7 is usually palpable and can help identify the midline of the back. A line drawn between the upper borders of the iliac crests across the midline of the back identifies the approximate level of L4 or the L4-L5 interspace.
CSEA is usually performed at the level of the L3 or L4 vertebrae in the adult patient, so that the spinal needle is introduced below the level at which the spinal cord ends. Lumbar and sacral nerve roots extending below the border of L1 form the cauda equina. Although these nerve roots are more sensitive to the effects of local anesthetics, their relative mobility within the CSF compared to the spinal cord reduces the risk that introduction of the spinal needle will cause direct trauma to the nerve roots at the lower lumbar levels.
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Figure 6
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Spinal cord and cauda equina. Note that the spinal cord ends at about L1, with the conus medullaris. Nerve roots travel further down as the cauda equina. Their relative mobility within the cerebrospinal fluid decreases the risk of neural damage with subarachnoid injections done at the L4 level. From Drake L, Vogl AW, Mitchell AWM, et al: Gray’s Atlas of Anatomy. Philadelphia: Churchill Livingstone Elsevier, 2008, p. 44.
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