Neuraxial Complications - Exam 1 Flashcards
Symptoms of PDPH
- HA - worse when sitting/standing & better when lying down
- 2-3 days post puncture
- HA felt frontal to occipital
- nausea
- light sensitivity, double vision, ringing in ears
Tx for PDPH
- bed rest
- NSAIDs
- Caffeine
- Epidural Blood patch
What nerves are affected w/ cauda equina syndrome?
L2-S5 & coccygeal nerve
Cause of cauda equina syndrome
high levels of LA drugs affecting nerve function
Factors that increase risk of cauda equina syndrome
- high concentration of LA (5% Lido in SAB)
- microcatheters - epidural
- Whiticare 25/26 = small needles
Signs/symptoms of cauda equina syndrome
- neuro complication can be permanent
- bowel/bladder dysfunction
- sensory deficits (feet/legs)
- back pain
- saddle anesthesia
- sexual dysfunction
- weakness/paralysis
Tx of cauda equina syndrome
- supportive care
- If compression present (disc, hematoma) - laminectomy needed <6hrs
Causes of Transient Neurological Symptoms
- improper pt positioning - stretches nerves (sciatic)
- myofascial strain & spasms
Factors that increase risk of transient neurological symptoms
- higher incidence w/ Lidocaine 5%
- surgical positions - lithotomy
- out pt surgeries - knee arthroscopies
S/S transient neurological symptoms
- radicular pain in back and buttocks - spreads down both legs
- starts w/i 6-36 hours after sx and lasts 1-7 days
Tx for Transient Neurologic Symptoms
- NSAIDs/opioids
- trigger point injections (spasms & pain)
What type of anesthetic is a unilateral block more common with?
Epidural
What are 2 common causes for a unilateral Epidural block?
- catheter inserted too far
- cath tip close to a nerve
How do you know there is a unilateral block?
Pt states they can still feel one side
What are possible solutions to fix a unilateral block?
- adjust the cath (pull out 1-2cm)
- Reposition pt w/ numb side up
- Admin more anesthetic - caution if 9cm dilated
- Cath replacement
What is the most common cause of LAST? What type of block is it most common with?
- Inadvertent intravenous injection
- more common w/ peripheral blocks
What is the most common symptom of LAST?
What about w/ Bupivacaine?
- Seizures
- Cardiac Arrest
LA concentrations
1-5 mcg/mL effect:
Analgesia
LA concentrations
5-10mcg/mL effect:
- Tinnitus
- Skeletal muscle twitches
- numb lips/tongue
- restlessness
- vertigo
- blurred vision
- hypotension
- myocardial depression
LA concentrations
10-15 mcg/mL effects
- Seizures
- LOC
LA concentrations
15-25 mcg/mL effects
- Coma
- respiratory arrest
LA concentrations
> 25 mcg/mL effect
- cardiovascular collapse
LAST
What 3 things increase the risk of CNS toxicity?
- Hypercarbia (vasodilation)
- Hyperkalemia (high Vrm)
- Metabolic Acidosis (ion trapping)
LAST
What 3 things decrease the risk of CNS toxicity?
- Hypocarbia (Vasoconstriction)
- Hypokalemia (lower Vrm)
- CNS depressants (raise seizure threshold)
LAST
LA decreases the heart’s ________, ________ ________, ____ ________, & the ________ ________ period.
- automaticity
- conduction velocity
- AP duration
- Effective refractory period
LAST
What determines the extent of cardiotoxicity r/t LA?
- the LA affinity to the VG Na channel
- Rate of dissociation from the receptor in diastole
LAST
Why is Bupivacaine so cardiotoxic?
- it has a high affinity to VG Na channel
- slower dissociation rate from receptor in diastole
LAST
order of 4 anesthetics in difficult of cardiac resuscitation
Bupivacaine > Levobupivacaine > ropivacaine > Lidocaine
Tx of LAST
- Manage the airway
- Tx Seizures (Benzos)
- Modified ACLS ) < 1 mcg/kg epi
LAST
Lipid Emulsion MOA
- 20% lipid molecules
- sequesters and reduces LA plasma concentration
Lipid Emulsion
Metabolic effects (heart):
- boosts myocardial fatty acid metabolism
- increases heart energy use
Lipid Emulsion
Inotropic effect
increases myocardial calcium influx & intracellular Ca concentration
Lipid Emulsion
Membrane Effect:
Impairs LA binding to VG Na Channels
Lipid Emulsion
Admin >70kg
- 100mL bolus (2-3min)
- 250mL infusion for 15-20min
- repeat or double if unstable
Lipid Emulsion
Admin < 70kg
- 1.5mL/kg bolus (2-3min)
- 0.25mL/kg/min infusion
- repeat or double if unstable
Lipid Emulsion
MAX DOSE
12mL/kg
LAST
How long do pts need observed after seizure?
after CV instability?
- 2 hrs - seizures
- CV - 4-6hrs
LAST ALGORITHM
What 4 meds should we avoid in these pts?
- LA
- BBs
- CCBs
- Vasopressin - pulmonary hemorrhage
What 3 things are an epidural/spinal hematoma associated with?
- pre-existing clotting/hemostasis abnormalities
- traumatic/difficult placement
- indwelling catheters & long-term anticoagulation
Epidural Hematoma
Cord ischemia is reversible if a ________ is performed in < ________.
Laminectomy, 8 hrs
What is a major symptom of epidural hematoma?
PAIN
What is Arachnoiditis
Inflammation of the meninges (inflamed arachnoid mater around spinal nerves)
Arachnoiditis 1st sign -
fever 2-3 days post procedure
Arachnoiditis causes -
- non-approved admin of drug into intrathecal/epidural space (med error)
- non-preservative free solutions
- betadine contamination
Arachnoiditis management
pain management & PT
What 2 things can arachnoiditis lead to?
- sclerosis of arachnoid membranes
- constriction of vascular supply
