Transcript Failed spinal anesthesia MGMC - Anesthesia Slides, Presentations

Failed spinal anesthesia
Dr. S. Parthasarathy
MD., DA., DNB, MD (Acu), Dip. Diab. DCA,
Dip. Software statisticsPhD ( physiology),
( IDRA )
Golden words of 1922
• Two conditions are absolutely necessary to produce
spinal anesthesia:
• puncture of the dura mater and subarachnoid
injection of an anesthetic agent.
• Gaston Labat
• 1922
Define it ?
• Spinal Anesthesia is considered to have failed
if anesthesia and analgesia have not effected
within 10 minutes of successful intrathecal
deposition of heavy bupivacaine and 25
minutes for plain bupivacaine
Only three options ?? Or more !!
Clinical definitions !!
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1. Not acted at all
2. Acted but deficient in
a) quantity,
b) Quality or
c) duration ??
Incidence -- < 1 % some studies 17 %
But acceptable is 3 -4 % in many reviews
Incidence
Incidence
Cant go near !!
• Failed lumbar puncture
• Dry tap ??
• Needle without the stylet – blood tissue clogs
• But not common
Faulty position
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Tip of table
Flexion
Shoulder straight ?
Kyphosis , scoliosis ? Fracture hip
Previous lamina surgery
The sitting is usually an easier option in ‘difficult’
patients, but sometimes the reverse is true.
• The role of the assistant !!
Position and adjuncts
• A calm, relaxed patient is more likely to assume and
maintain the correct position,
• so explanation (before and during the procedure)
• Gentle slow handling
• light anxiolytic premedication
• local anaesthetic infiltration without obscuring the
landmarks, but must include both intradermal and
s.c. injection.
Needle insertion
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Which space ?
Midline , hitting bone
Cephalad
Rarely inferior and lateral
Get the mental picture
• Midline calcification think paramedian
Spinal USG
Pseudo-successful lumbar puncture
• Getting the fluid but not CSF
• Epidural top ups
• Arachnoid cyst
Solution injection errors
• Aspiration
• Correct dose
• Correct drug
Get the feel !!
Or
CSF alone is
dripping
Dose selection
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Correct dose –
specific local anaesthetic used
the baricity of that solution
the patient’s subsequent posture,
the type of block intended,
anticipated duration of surgery
• Mass matters
Loss of injectate
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In the needle remains
Luer lock
Movement
Labour pain ?
Back of the other hand
Aspirate but don’t displace
Pencil point needles problems
Pictures from the internet for closed academic purpose only
Inadequate intrathecal spread
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Anatomical changes,
position,
space injected ,
CSF volume
Identification errors
• Which drug is local
• Which is test dose
• Which is spinal drug
• Confusion ?
Chemical incompatibility
• Clonidine + opioid + LA
• LA + 2 opioids
Not well defined
• LA with ketamine and midazolam
• LA with adrenaline
• The older, ester-type local anesthetics are
chemically labile
• heat sterilization and prolonged storage ?? ,
make them ineffective because of hydrolysis??
• Newer Amides are stable
“Resistance”
• Very rarely a failed spinal anaesthetic has
been attributed to physiological ‘resistance’ to
the actions of local anaesthetic drugs,
• Sodium channel mutation
• Scorpion stings !!
• Anecdotal
This batch is not good !!
• The neuroscience division of AstraZeneca received
562 ‘Product Defect Notification’ reports in the 6
year to December 31, 2007, all ascribing failed spinal
anaesthetics to ineffective bupivacaine solution
• But chemical analyses proved everything Ok in
all cases
Failure of subsequent management
• Level – covert pinch – glance of the eyes
between surgeons and anaes – yes OK – start
• Abdomen cleaning , mopping – sedatives
• Can we stay in an abnormal position for hours
? – table and position are for surgeons
Injected proper but ??
Tarlov Cyst
• Fluid-filled nerve root
valved or nonvalved
cysts found most
commonly at the sacral
level of the spine
• Asymptomatic TC are
present in 5-9 %.
Female are more
frequently affected
• Treatment is drainage
of CSF or surgery
High CSF volume
Volume ??
Ballooned dural sac
Can happen !!
• Some pain fibres pass via sympathetic nerve
and then via sympathetic chain to reach the
spinal cord at higher level than the site of
injection and may be the cause of failure.
• Lateral approach -- dural investment of nerve
root resulting in false feeling of placement of
needle tip in the subarachnoid space
Rapid sequence spinal anesthesia –
more likely to fail
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IV access , monitors with staff 1
Chlorhexidine preparation with staff 2
No local
Non touch spinal
No additives
A larger dose
Start as the block starts
Be Ready for GA
5-7 minutes
Non touch spinal by me in 40 seconds
Management of failure
Prevention is better than cure
Clinical and medicolegal!!
• How and when it is found out
• Tincture of time 15 minutes
• Then alternative arrangement
No block:
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the wrong solution,
the wrong place,
or it is ineffective.
Repeating the procedure or conversion to
general anesthesia
• the patient has significant pruritus, - only
opioid injected
Good block but less height
• Flex knees and hips and trendelenberg
• Obstetrics – left and right lateral and head
down
Patchy blocks
• This term is used to describe a block that appears
adequate in extent, but the sensory and motor
effects are incomplete.
• Some sensory and some motor segments spared and
quality is not that good.
Repeat – GA – sedation or local infiltration
When we repeat
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Excessive repeat dose – need to reduce !
Higher level of injection
Is it not neurotoxic
Anesthetised nerves prone for nerve injuries
• Recourse to an epidural in technical
difficulties
• Rescue measures and GA – beware of already
existing sympathetic block and hypotension
• Document and explain to patients but avoid
medico legal problems
• Look for local hospital problems
Three muskateers
• Right place
• Right drug
• Right dose
• Decide
Failure
• Lumbar puncture
Failure
• Local injection
Failure
• Spread
Failure
• Action on nerves
abnormalities of the spine,
thickened ligamentum flavum,
flexible small spinal needle, and
improper positioning of the patient
or the inexperience of the person
giving the block.
Leaks , partly outside , wrong
drugs ,gauge of needle , subdural
,aspirate
Anatomical changes, position, space
injected ,CSF volume
Bloody taps, high CSF pH, repeated
autoclave. resistance, age, drug
volume, which drug
• Alfred E. Barker wrote that for successful spinal
analgesia
• it is necessary
‘to enter the lumbar dural sac
effectually with the point of the needle, and to
discharge through this, all the contemplated dose of
the drug, directly and freely into the cerebrospinal
fluid, below the termination of the cord’
Feel and give
Failure -Prevention of failure is the most
important step
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Preoperative noted –
Assess and assure
Sedate
Drugs which increase
Position, valsalva ,
cough , EVE
• Repeat – dose drug !!
• GA
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Intraoperative noted
Assess
Assure
Local
Sedate
GA
•Thank you
all