Failed spinal anesthesia can occur for several reasons: 1. Anatomical abnormalities of the spine like thickened ligaments or spinal deformities can make proper needle placement difficult. 2. Technical errors like using too small of a needle, improper patient positioning, or inexperience of the practitioner performing the block can lead to failure. 3. Injection issues such as injecting the anesthetic outside of the subarachnoid space, using the wrong drug or dose, bloody taps, or repeated autoclaving altering the drug properties may cause failure. Prevention through careful patient assessment, proper technique and addressing any identified risks is important to reduce failure rates.

1. Failed spinal anesthesia
Dr. S. Parthasarathy
MD., DA., DNB, MD (Acu), Dip. Diab. DCA,
Dip. Software statistics-
PhD ( physiology),
( IDRA )

2. 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

3. 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

4. Only three options ?? Or more !!

5. Clinical definitions !!
• 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

6. Incidence

7. Incidence

8. Cant go near !!
• Failed lumbar puncture
• Dry tap ??
• Needle without the stylet – blood tissue clogs
• But not common

9. Faulty position
• 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 !!

11. 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.

12. Needle insertion
• Which space ?
• Midline , hitting bone
• Cephalad
• Rarely inferior and lateral
• Get the mental picture
• Midline calcification think paramedian

13. Spinal USG

14. Pseudo-successful lumbar puncture
• Getting the fluid but not CSF
• Epidural top ups
• Arachnoid cyst

15. Solution injection errors
• Aspiration
• Correct dose
• Correct drug
Get the feel !!
Or
CSF alone is
dripping

16. Dose selection
• 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

17. Loss of injectate
• In the needle remains
• Luer lock
• Movement
• Labour pain ?
• Back of the other hand
• Aspirate but don’t displace

18. Pencil point needles problems
Pictures from the internet for closed academic purpose only

19. Inadequate intrathecal spread
• Anatomical changes,
• position,
• space injected ,
• CSF volume

20. Identification errors
• Which drug is local
• Which is test dose
• Which is spinal drug
• Confusion ?

22. Chemical incompatibility
• Clonidine + opioid + LA
• LA + 2 opioids
• LA with ketamine and midazolam
• LA with adrenaline
Not well defined

23. • The older, ester-type local anesthetics are
chemically labile
• heat sterilization and prolonged storage ?? ,
make them ineffective because of hydrolysis??
• Newer Amides are stable

24. “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

25. 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

26. 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

27. Injected proper but ??

28. 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

29. High CSF volume

30. Volume ??

31. Ballooned dural sac

32. 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

33. Rapid sequence spinal anesthesia –
more likely to fail
• 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

34. Non touch spinal by me in 40 seconds

35. Management of failure
Prevention is better than cure

36. Clinical and medicolegal!!
• How and when it is found out
• Tincture of time 15 minutes
• Then alternative arrangement

37. No block:
• 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

38. Good block but less height
• Flex knees and hips and trendelenberg
• Obstetrics – left and right lateral and head
down

39. 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

40. When we repeat
• 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

41. • 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

42. Three muskateers
• Right place
• Right drug
• Right dose

43. • Decide
• Lumbar puncture
• Local injection
• Spread
• Action on nerves
Failure
Failure
Failure
Failure
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

44. • 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’

45. Feel and give

46. Failure -Prevention of failure is the most
important step
• Preoperative noted –
• Assess and assure
• Sedate
• Drugs which increase
• Position, valsalva ,
cough , EVE
• Repeat – dose drug !!
• GA
• Intraoperative noted
• Assess
• Assure
• Local
• Sedate
• GA

47. •Thank you
all