Management of Labor Epidural: Tools of the Trade

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Management of Labor Epidural Tools of the Trade

• Dmitry Portnoy, MD
• Anesthesiology Department

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Q When is the best time to get an epidural?A
Right after you find out you're pregnant.
www.babiescantread.com/maternitees.htm
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Intensity of Pain in Labor
http//www.manbit.com/oa/oaindex.htm
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Physiology of Pain in Labor

• 1st stage of labor mostly visceral
• Dilation of the cervix and distention of the
  lower uterine segment
• Dull, aching and poorly localized
• Slow conducting, visceral C fibers, enter spinal
  cord at T10 to L1
• 2nd stage of labor mostly somatic
• Distention of the pelvic floor, vagina and
  perineum
• Sharp, severe and well localized
• Rapidly conducting A-delta fibers, enter spinal
  cord at S2 to S4

T10
L1
S2
S4
http//www.manbit.com/oa/oaindex.htm
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Anatomy of the Epidural Space

• Boundaries of epidural space
• Superior - the foramen magnum
• Inferior - the sacral hiatus and sacro-
  coccygeal membrane
• Anterior - the posterior longitudinal lig.
• Posterior - periosteum of laminae of the
  vertebrae and the lig. flavum
• Lateral - periosteum of the pedicles and
  intervertebral foraminae
• Epidural space contains
• Dural sac and nerve roots
• Blood vessels and lymphatics
• Connective and fatty tissue

From Cousins, Neural Blockade
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Spread of Epidurally Injected Solutions

• Drugs must travel through
• dura matter arachnoid matter
• CSF pia matter
• white matter gray matter
• Rapid access via dural cuff
• Competing pathways
• Uptake into epidural epidural fat
• Uptake into systemic circulation

From Cousins, Neural Blockade
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The Perfect Labor Epidural

• Safe (for both mother and fetus)
• Easy and painless placement
• Fast onset, easy administration, tight control
• Effective analgesia (for both stage I and II)
• Reliable extension for indicated procedures
• Minimal side effects (for both mother and fetus)
• No adverse effects on labor progress
• Minimal complications
• High patient satisfaction overall

SAFETY COMES FIRST
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Terms and Incidence of Unsatisfactory Epidural
Block
                         
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Etiology and Contributing Factors in
Unsatisfactory Epidural Block
Unsatisfactory epidural block
Patient and surgical factors
Performance factor
Anatomical considerations
Methodology and equipment
Portnoy D, Vadhera RB., MechanismsAnesthesiol
Clin North America. 2003 Mar21(1)39-57
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Regional Anatomy and the Quality of Labor
Epidural

• Effects of the anatomy on the successful
  placement of LEC
• Obesity, musculoskeletal abnormality, midline
  structures
• Details of the Ligamentum Flavum - midline gaps
  (failure to fuse)
• Effects of the geometry of epidural space on drug
  distribution
• Amount and distribution of fatty tissue
• Presence of midline structures
• plica mediana dorsalis (dura matris) - Luyendijk
  , 1963
• midline adhesion of dura mater - Singh, 1967
• epidural plica mediana dorsalis - Savolaine, 1988
• dorsomedian connective tissue band - Blomberg,
  1986
• Spinal nerve root diameter - Galindo, 1975

TECHNIQUE, NOT ANATOMY IS LIKELY TO BLAME
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Etiology and Contributing Factors Technique,
methodology and equipment

• Initial catheter misplacement - incorrect
  placement
• Malposition in anterior or paravertebral
  (lateral) epidural space
• Transforaminal escape
• Increased skin-to-epidural space distance
• Catheter related
• Catheter migration after initial proper placement
• The distance of insertion inside the epidural
  space
• Uniport versus multiport epidural catheters
• Catheter malfunction and catheter defects
• Air for loss-of-resistance technique
• Method of injecting local anesthetic
• Patients position

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Etiology and Contributing FactorsPatient-related
and other risk factors

• Inherited and acquired anatomical features
• Morbid obesity and body mass index greater than
  30
• Short and tall individuals
• Previous spinal surgery and a variety of
  musculoskeletal disorders
• History of a previous placement of epidural
  catheter
• Radicular pain during epidural placement
• Posterior presentation of the fetus
• Inadequate analgesia from the initial dose
• Duration of labor more than 6 hours
• Technical skills, or performance factors

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Successful Management of Labor Epidural

• Preoperative considerations and planning ahead
• Initial placement of LEC methodology and
  equipment
• Assessment and monitoring of LEA
• Management of existing epidural catheter
• Extension of LEA for indicated procedures
• Postpartum management of epidural catheter

BEFORE
AFTER
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Preoperative Considerations

• Maternal Obstetric
• Factors
• Nulliparity
• Earlier placement of LEA
• Heavier fetal weight
• Abnormal fetal presentation
• Dysfunctional labor

• Planning Ahead
• Patients expectations
• Choice of LEA vs CSE
• Patient controlled technique
• Other technical issues
• Tailoring to high risk patient

SAFETY COMES FIRST- RESCUCITATION EQUIPMENT
Hess et al, Predictors of Pain During Labor
Epidural, AA, 93(2), 2001, 414-418
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Initial Placement of LEC

• Positioning of the patient and the operator
• Identification of the landmarks
• Thorough local infiltration (start with 25g
  needle)
• Loss of resistance technique (to air vs NS)
• Length of LEC inside the epidural space
• Problem solving during the placement of an
  epidural
• Unable to identify midline (position? landmarks?)
• Unable to identify epidural space (position?
  landmarks? needle?)
• Unable to thread the catheter (true space? opened
  space?)

NEVER ADVANCE IF PATIENT COMPLAINS OF PAIN!
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The perfect epidural puncture ?!?
http//www.uam.es/departamentos/medicina/anesnet/j
ournals/ija/.htm
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Assessment of the Quality of Labor Epidural

• Know the baseline
• Pain score
• Assessment of the sensory level
• Assessment of motor blockade (Bromage score)
• Degree of sympathetic blockade

ALWAYS AVOID HYPOTENSION!
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Unsatisfactory Labor Epidural AnalgesiaManagement
Options

• Catheter manipulation
• Additional volume of local anesthetic
• Patients position manipulation
• Replacement of the epidural catheter
• A single shot spinal anesthesia
• Continuous spinal anesthesia
• Combined spinal-epidural anesthesia
• Placement of an additional epidural catheter
• Supplementation with intravenous medications

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Management of Unsatisfactory Epidural
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Management of Unsatisfactory Epidural (cont)
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Labor Epidural Pearls (Humble Suggestions)

• No labor epidural is worth the complications
• Do not insist unless medically indicated
• Consider other pain control options if LEA seems
  to be risky
• Give parturient realistic expectations
• Consider labor dynamics
• Constant communication during the procedure
• Any LOR is true unless otherwise proved
• Taping job is as important
• Do not give more than 3 cc of LA per 1.5 min
• Treat every dose as a test dose

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Epidural Pearls (Humble Suggestions) cont.

• The longer the skin-to-epidural distance, the
  deeper the catheter goes inside the space
• Routinely place LEC 3-4 cm into the epidural
  space
• Avoid placing the LEC longer than 6 cm into the
  space
• Do not allow the level to recede
• Avoid hypotension
• No LA with instant onset (not even close to)
  unless . . .
• Consider CSE

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HAPPY EPIDURALS FOR ALL OF US!