Exam 1 Spinal & Epidural Neuraxial Anesthesia [6/04/24] Flashcards
Failure of a dura puncture site to properly “seal over” once breached by a needle can cause:
Postdural Puncture Headache
Why does the headache actually occur in the instance of a PDPH?
The continuous CSF leak lowers the pressure in the brain area which causes the brain to sag slightly and stretch the surrounding membranes, leading to the headache.
Does sitting/standing or laying down make the headache in a PDPH better?
Sitting/Standing = worse
Laying down = better
When does a PDPH typically occur post-puncture?
2-3 days
In what manner does a PDPH spread across a patients head?
Frontal to occipital
(Forehead to back of head)
3 factors that increase the risk of developing a PDPH:
Young
Female
Pregnant
Less invasive Treatments for PDPH:
Bed rest
NSAIDs
Caffeine
More invasive treatments for PDPH:
Epidural Blood Patch
Sphenopalatine Ganglion Block
Describe the process of an epidural blood patch for PDPH:
How successful is this treatment?
Injection of 10-20 mls of a patient’s own blood into the epidural space
About 90% success rate
True or False:
Epidural blood patch is not routinely recommended within 24 hrs of dural puncture.
TRUE
48 hours has shown to be the standard
Describe the process of using the SPG block as a treatment for PDPH:
- Soak a cotton swab in a LA
- Tilt the patients head back and insert the swab into their nose
- Leave the swab for about 5-10 minutes
Is paresthesia more common in epidurals or CSE cases?
CSE
When preparing a patient’s back for a neuraxial block, which skin prep options are used?
Which are the most effective?
Iodine
Chlorhexidine
Alcohol
(Combo of Chlorhexidine and alcohol are most effective)
Which nerves are affected in Cauda Equina Syndrome?
L2-S5
What factors may increase the risk of Cauda Equina Syndrome?
High concentration of LA (5% Lidocaine in SAB)
Use of Microcatheters
Whiticare 25/26 needles
S/S of Cauda Equina Syndrome:
Bowel/Bladder Dysfunction
Back Pain
Saddle Anesthesia
Paraplegia (Late sign)
Treatment of Cauda Equina Syndrome:
Supportive Care
(If compression = immediate laminectomy)
Improper patient positioning during neuraxial procedures can stretch nerves causing ___.
Transient Neurologic Symptoms
Factors increasing the risk of Transient Neurologic Symptoms:
- Use of 5% Lidocaine
- Lithotomy Position
- Outpatient Knee Arthroplasty
Severe radicular pain in the back and buttocks that spreads down both legs is a sign of ___.
Transient Neurologic Symptom
Treatment for Transient Neurologic Symptoms
NSAID’s
Trigger Point Injections
After which neuraxial procedure are retained catheter fragments most common?
Epidurals
What is a common cause of seeing blood in the epidural needle or catheter?
Needle is too far lateral
Risk factors for epidural vein cannulation:
Multiple attempts
Pregnancy
Stiff Catheters
Epidural Vein trauma
Common causes of unilateral epidural block
The catheter may have been inserted too far, exiting the epidural space through intervertebral foramen.
The catheter tip might be too close to a nerve
Solutions to resolve unilateral epidural block
Adjust the Catheter
Lateral Decubitus Position
Administer More diluted Anesthetic
Catheter Replacement
Most common cause of L.A.S.T.
Inadvertant injection
Most frequent symptom of L.A.S.T.:
What about with Bupivicaine
Seizures
CV Collapse
Is L.A.S.T. more common in peripheral nerve blocks or epidurals?
Peripheral
Things that increase the risk of CNS toxicity in LAST
Hypercarbia (Increased CPP)
Hyperkalemia (Easily excitable)
Metabolic Acidosis
Things that decrease the risk of CNS toxicity in LAST
Hypocarbia
Hypokalemia
CNS depressants
LAST Treatment
Airway
Treat seizures
Modified ACLS
Lipid Emulsion therapy (20%)
Important things of note with the modified ACLS treatment for LAST
Be cautious with epinephrine –> lowers effectiveness of lipid emulsion therapy
Use less than 1 mcg/kg
When treating seizures for LAST, use ___ and avoid ___.
Benzos
Propofol
Dose for lipid emulsion therapy for over 70kg patient:
100 ml bolus for 2-3 min followed by 250 ml infusion over 15-20 mins
(Repeat or double if unstable)
Dose for lipid emulsion therapy for under 70kg patient:
Start with 1.5 ml/kg bolus for 2-3 min followed by 0.25 ml/kg infusion
(Repeat or double if unstable)
Max dose of lipid emulsion therapy
12 ml/kg
MOA for why lipid emulsion works:
Lipid Sink: reduces LA in plasma
Inotropic: increase calcium influx
Impairs LA from binding to V-G Na channels
Epidural and Spinal Hematoma have been shown to be associated with:
Pre-existing abnormalities in clotting hemostasis
Traumatic or difficult needle placement
Indwelling catheters and long-term anticoagulation
Cord ischemia can be reversible if laminectomy is performed in ____.
< 8 hrs
Arachnoiditis can be caused by:
First sign?
Nonapproved administration of drug into intrathecal or epidural space (medical error)
Using non-preservative free solutions
Betadine contamination (wipe off)
Fever (3-4 days after)
3 common reasons for Neuraxial Anesthesia failure?
- Wrong Dose
- Wrong Location
- Wrong Position
Always be prepared to do ___ with any neuraxial case.
General Anesthesia
Things that could go wrong during Neuraxial anesthesia that could lead to performing GETA?
It happens in a FLASH:
Failed Block
LAST
Anaphylaxis
Severe CV Collapse
“High Spinal”
What are the 2 Cutting Needles?
Quincke
Pitkin
Advantage of using pencil-point tip in SAB?
Fewer Contaminants
You can feel the “Pop”
Less risk of PDPH
Common Problems when doing a SAB
Lack of free flow CSF after turning 360 degrees
No Swirl
Resistance
Parasthesia
Blood instead of CSF
No Block (Look at expiration date)
Both of these epidural needles are 15 degrees:
Which has “wings”?
Hustead
Weiss (Has wings)
This type of epidural needle is used when catheter placement is difficult, or the angle is too steep:
Crawford (0 Degree curvature)
This needle has the most curvature (30 Degrees) and the blunt tip is less likely to puncture the subarachnoid space
Tuohy
What is the lenth of the tuohy needle from tip to hub?
9 cm
Do multi-orificed or single epidural catheters have a lower incidence of inadequate anesthesia?
Which has a lower incidence of inadvertent intravascular placement?
Multi-orificed
Single
Optimal Epidural space length/depth is ___?
3-5 cm
If the total length of your epidural needle is 9 cm and 5 cm is visible, what is the distance from the skin to the epidural space?
4 cm
When is it best to perfrom an epidural on someone with a lumbar tattoo?
What may you also need to do?
Within 5 months of the tattoo application
Paramedian approach
What is used as the test dose for epidural?
1.5% Lidocaine with Epi (1: 200,000)
(3 mls)
3 Important numbers to record after performing an epidural:
- Depth to epidural space
- Catheter marking at the skin
- Catheter depth/length in the epidural space
What is the secondary/ less useful method for identifying entrance to the epidural space? (Not L.O.R.)
Hanging drop method
What are we watching for when giving our test dose for an epidural?
Increase in HR by 20% or more
Pt complaint of tinnitus, metallic taste, numbness around mouth
Dense motor block within 5 min (Accidental Spinal)
What is a special consideration in regard to the epidural test dose on a pregnant woman?
Give it after a contraction ends for a clearer result
Initial dose and increments for an epidural?
1-2 mls/segment
Given in 5 ml increments
Do we want to give the top-up dose before or after “two-segment regression”?
Before
Recommended Top Up time from initial dose for Lidocaine and Mepivicaine
60 mins
This LA has a Top Up time of 45 mins from the initial dose?
2-Chloroprocaine
We can expect that after ___ mins from the initial dose, Bupivicaine and Ropivicaine will need a Top Up dose.
120 mins
Common problems seen with epidurals:
“Wet Tap” = Went into dura, seeing CSF
Paresthesia
Unable to thread catheter (Maybe Flica)
Aspirating Blood
Positive Test Dose response
“False” positive test dose
