Term
How serious is injury to the epidural veins associated with needle or catheter injury usually?
What increases the risk? |
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Definition
Needle or catheter injury to the epidural veins often causes minor bleeding in the spinal canal, but is usually benign and self-limiting.
The risk increases with anticoagulated patients, or patients with a history of bleeding disorders or platelet counts. |
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Term
| What is the normal platelet count required for regional anesthesia? |
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Definition
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Term
What increases the risk for spinal or epidural hematomas?
What are the symptoms? |
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Definition
Repeated attempts to place a spinal or epidural catheter, anticoagulation, as well as during insertion and removal of catheters.
Rapid onset with sharp back and leg pain with progressive numbness and motor weakness or sphincter dysfunction. |
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Term
| What must be done if a spinal or epidural hematoma is suspected? |
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Definition
| A CT or MRI should be done emergently. Neurosurgical decompression within 8-12 hours of onset has good outcomes. Decompression after this time leads to longer term problems. |
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Term
| True or false: Patients on low dose aspirin may receive regional anesthesia? |
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Definition
| True. Patients on low dose ASA or NSAIDS can receive regional despite last dose. Herbals are not proven to cause concern. |
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Term
| True or false: SQ or mini dose heparin prevents the use of regional anesthesia. |
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Definition
| False. It is okay with mini dose heparin |
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Term
What are the standards for regional anesthesia associated with IV heparin?
(How long on hold after placement?
When can epidurals be pulled when pt on heparin?
When can heparin be restarted after catheter dc'd?) |
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Definition
| No regional until PTT is normal. Heparin infusion to be held until 1 hour after SAB/epidural placement. Indwelling catheters pulled 2-4 hours after last heparin dose + normal PTT. Heparin can be initiated 1 hour after catheter removed. |
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Term
When someone is on coumadin, what INR is necessary before catheter can be pulled?
How long should you wait to do a regional on someone who has had a thrombolytic or fibrinolytic?
Ticlid? Plavix? |
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Definition
Less than 1.5
No regional for 10 days after thrombolytic or fibrinolytic. 14 days after Ticlid; 7 days after Plavix. |
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Term
Fill in the blanks.
In spinal anesthetics, the _____ of the local anesthetic is more important than the ______. In epidural anesthesia, the ______ of the drug determines the spread. |
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Definition
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Term
| In epidural anesthesia, where does the sensory interruption take place? |
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Definition
| In the anterior and posterior nerve roots as they pass through the epidural space on their way to the periphery. |
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Term
| When the afferent and efferent rootlets combine to form the spinal nerve, what substance covers the spinal nerve? Where does this combining occur? |
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Definition
Dura mater
Epidural space |
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Term
What type of anesthesia delivers a more intense block: SAB or epidural? Why?
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Definition
| SAB--the dura and arachnoid mater are difficult to penetrate. With an epidural, the initial blockade occurs via the spinal roots, then works past the dural sleeve into the rootlets and CSF. (DIFFUSION dependent) |
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Term
How much more local/opiod is required to provide an epidural block vs. a SAB?
Where do opioids work? How could an epidural opioid create a greater systemic opioid concentration than that in the CSF? |
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Definition
5-8X
Substantia gelantinosa
The epidural veins |
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Term
| Due to the variability in the sensitivity of different types of nerves to local anesthetics, what can be accomplished? |
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Definition
| Different types of blocks--sometimes just sensory, sometimes sensory and motor. |
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Term
| The band of distribution of analgesia delivered via epidural is based on what? |
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Definition
| The location and dose given. |
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Term
Where can epidurals be placed?
Epidurals provide coverage to dermatomes--what does this mean? (not definition of dermatome, but rather, what is the implication) |
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Definition
In all spinal segments (cervical, thoracic, lumbar, sacral)
The coverage is segmental--not a complete block distal to the start. |
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Term
| What does conversion of an epidural to a spinal mean? |
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Definition
| It is NOT injected into the SAS, but rather an overwhelming volume creates spinal-like blockade. |
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Term
From superficial to deep, what layers are crossed when placing an epidural?
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Definition
Skin
SQ
Supraspinous ligament
Interspinous ligament
Ligamentum flavum
Epidural space |
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Term
What is the superior limit to the epidural space? Inferior?
What is the safest point of entry to the epidural space? Why? |
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Definition
Foramen magnum
Sacral hiatus (sacrococcygeal membrane)
Midline--the epidural space narrows posteriorlaterally. |
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