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Epidural Analgesia
When bad catheters happen to good anesthetists.
Michael Rieker, DNP, CRNA, FAANDirector, Nurse Anesthesia Program
Wake Forest School of Medicine
History of Epidural Catheters
1901 First epidural injection
1931 Aburel- silk ureteral catheter for OB
1930 – 1950: random materials available to individual practitioner
1950-1960: 1mm PVC cut from industrial roll and sterilized.
1962: Lee’s catheter-smooth tip, side hole @ 1cm
Safer than general (?)… but not without risk
145,550 epidurals administered intravascular injection = 1 in 5,000 (0.02%) intrathecal injection = 1 in 2,900 (0.035%) subdural injection = 1 in 4,200 (0.024%) high or total spinal block = 1 in 16,200 (0.006%)
Jenkins JG. Some immediate serious complications of obstetric epidural analgesia and anaesthesia: a prospective study of 145,550 epidurals. International Journal of Obstetric Anesthesia. 14(1):37-42, 2005 Jan.
Safer than general (?)… but not without risk
19,259 deliveries; neuraxial labor analgesia rate was 75%; overall failure rate was 12%
After adequate initial placement, 6.8% required replacement. (1.5% had multiple replacements)
Intravenous placement- 6% (46% were made functional) Wet tap-1.2% The incidences of overall failure, intravenous catheter, wet tap,
inadequate analgesia and catheter replacement were lower in patients receiving combined spinal-epidural analgesia.
For cesarean section, 7.1% of pre-existing labor epidural catheters failed and 4.3% of patients required conversion to general anesthesia. Spinal anesthesia for cesarean section had a lower failure rate of 2.7%, with 1.2% of the patients requiring general anesthesia.
Pan PH. Bogard TD. Owen MD. Incidence and characteristics of failures in obstetric neuraxial analgesia and anesthesia: a retrospective analysis of 19,259 deliveries. [Journal Article] International Journal of Obstetric Anesthesia. 13(4):227-33, 2004 Oct.
Our goals:
Pick a winner
Get it in
Keep it in
Make it work
Respond when it goes in the wrong place
Pull it out
Our goals:
Pick a winner Get it in
Keep it in
Make it work
Respond when it goes in the wrong place
Pull it out
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Types of Catheters Types of Catheters
Material Polyamide Nylon (Braun, Portex) Spring wound polyurethane polymer (Arrow) Hybrid (Braun Soft-tip)
Orifices Single end hole Multiple side holes
Nylon catheters
Greater tensile strength
More often associated with multiple side orifices
Stiff
Greater incidence of venous cannulations, paresthesias
Soft catheters
Greater ease of threading Resistant to kinking Less paresthesias and vein cannulations Some require stylet Usually with single orifice More likely to curl Weaker; prone to becoming lodged, separated,
and possibly broken upon withdrawal
Arrow Flex-Tip Cath Catheter comparison
Portex Arrow(Soft)
Paresthesia 39 3
Vein Cannulation 11 0
Inability to insert 5 (*ns) 0
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Catheter Strength
Asai T, Yamamoto K, Hirose T, Taguchi H, et al. Breakage of epidural catheters: a comparison of an arrow reinforced catheter and other nonreinforced catheters. Anesth Analg 2001; 92: 246–8
Manufacturer Reported malfunctions 1991-2004
Arrow 248
Braun 114
Abbott 75
Baxter 31
Smith 25
Portex 20
Epimed 17
Becton Dickson 2
“Hybrid” catheter- Braun Soft-tip
Multi-orifice catheters
Better spread
Potential for Multi-compartmental or partial block
Unilateral block half as frequent than with single-orifice catheters (8% vs. 16%)
Dickson MA. Moores C. McClure JH. Comparison of single, end-holed and multi-orifice extradural catheters when used for
continuous infusion of local anaesthetic during labour. British Journal of Anaesthesia. 79(3):297-300, 1997 Sep.
Significantly less unilateral block or unblocked segments
Segal S. Eappen S. Datta S. Superiority of multi-orifice over single-orifice epidural catheters for labor analgesia and cesarean delivery. Journal of Clinical Anesthesia. 9(2):109-12, 1997 Mar.
Multi-orifice catheters
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D. McAtamney, C. O'hare, J. P. H. Fee An in vitro evaluation of flow from multiholeepidural catheters during continuous infusion with four different infusion pumps Anaesthesia 1999;54(7):664–669
D. McAtamney, C. O'hare, J. P. H. Fee An in vitro evaluation of flow from multiholeepidural catheters during continuous infusion with four different infusion pumps Anaesthesia 1999;54(7):664–669
To work well, a continuous infusion pump has to act like a
bolus infusion device.
Single-orifice catheters
Better spread to sacrum “...epidural catheter design does affect the distribution of
solutions in the epidural space. Single orifice epidural catheters compared favourably with multi-orifice catheters, resulting in more even distribution and sacral extension of dye.”
Magides AD. Sprigg A. Richmond MN. Lumbar epidurography with multi-orifice and single orifice epidural catheters. Anaesthesia. 51(8):757-63, 1996 Aug.
Our goals:
Pick a winner
Get it in Keep it in
Make it work
Respond when it goes in the wrong place
Pull it out
Does position matter?
~100 patients each sitting or lateral
Vein cannulation 16% in sitting vs. 4% in lateral position
Bigat Z. Boztung N. Onder G. Ertok E. A rare complication of epidural catheter. Acta Anaesthesiologica Scandinavica. 49(4):589-90, 2005.
Are all spaces created equally?
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Brown D. Atlas of Regional Anesthesia.W.B. Saunders, 1992; pg 290
Where do catheters go?Where do catheters go?
Deviation from midline more likely vein cannulation or paresthesia.
20% of catheter tips lay outside the lateral margins of the vertebral bodies
Lateral foramen- catheter deviation r/t distance inserted.
Where do catheters go?
Catheters track more straight into space if inserted at 50º vs. 90º
Takeyama K. Yamazaki H. Maeda M. Tomino K. Suzuki T. Tokai Journal of Experimental & Clinical Medicine. 29(2):27-33, 2004 Jun.
Insertion vs. coiling
Fluoroscopy, paramedian approach
Started at T9; reached to either T6-7 (obtuse 60%) or T7-8
(acute-40%)
Ryu HG. Bahk JH. Lee CJ. Lim YJ. The coiling length of thoracic epidural catheters: the influence
of epidural approach angle. British Journal of Anaesthesia. 2007;98(3):401-4.
Coiling Length Acute Obtuse
Mean 4.9 7.4
Min-Max 95% CI 3.8-6 6-8.7
Ryu HG. Bahk JH. Lee CJ. Lim YJ. The coiling length of thoracic epidural catheters: the influence of epidural approach angle. British
Journal of Anaesthesia. 2007;98(3):401-4.
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“False loss of resistance”
Out of sight… out of epidural space?
Lateral catheter = unilateral block
Double, double, Coil and trouble
Coil / knot
Arrow: 7 cephalad
3 caudad
1 same space
Portex 3 cephalad
3 same
1 caudad
Martin R. Pirlet M. Parent M. Gingras F. Evaluation of epidural catheter tip position. Canadian Journal of Anaesthesia. 50(9):963; 2003 Nov.
Double, double, Coil and trouble
19ga Arrow Flex-Tip in 45 patients
median coiling length- 2.8 cm (1.0–8.0 cm)
Only 6 (13%) threaded >4 cm without coiling
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Double, Double, Coil and Trouble
Pain & sensory loss in thigh
Catheter coiled around L3 nerve root
Stretched and broke on withdrawal
Double, Double, Coil and Trouble
Catheter inserted 9 cm.
Resistance on withdrawal. Steady pressure finally removed catheter (somewhat painfully)
Brichant, J.F., Bonhomme, V. and Hans P. (2006) On knots in epidural catheters: a case report and a review of the literature International Journal of Obstetric Anesthesia15(2): 159-162
Double, Double, Coil and Trouble
Catheter inserted 8 cm.
Attempt to pull back to 5cm met with resistance.
Knot and loop found at 7.5cm Huang, J. Another case of knotting of an epidural catheter. AANA J. 2010;78(2):93-94.
Double, double, Coil and trouble
Looping doesn’t always occur in the patient
Where do catheters go, Up or down?
Direction of insertion does not make much of a difference.
45 patients. Surgery affecting sacral nerves
Catheters: half up; half down.
No difference in onset time, duration, anesthetic level, and analgesic effect
Liu CC. Chau SW. Spielberger J. Liu PH. Chou WY. Tan PH. Evaluation of the effects of caudal or cephalic epidural catheterization on the characteristics of lumbar epidural anesthesia. Acta Anaesthesiologica Taiwanica: Official Journal of the Taiwan Society of Anesthesiologists. 43(2):79-83, 2005
Catheter shearing
Don’t withdraw through needle
Patient movement may cause shearing Noblett, Karen (02/2007). "Sheared epidural catheter during
an elective procedure." Obstetrics and gynecology, 109 (2), p. 566.
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Improving technique
Ultrasound guidance to find ES in pediatric patients.
US correlated 0.88 with conventional LOR Rapp HJ. Folger A. Grau T. Ultrasound-guided epidural catheter insertion in children. Anesthesia &
Analgesia. 101(2):333-9, table of contents, 2005
Ultrasound estimation of depth significantly improved placement rate
Vallejo MC et al, Ultrasound decreases the failed labor epidural rate in resident trainees, Int J Obstet Anesth 19(4):373-8, 2010.
Our goals:
Pick a winner
Get it in
Keep it in Make it work
Respond when it goes in the wrong place
Pull it out
Disconnection
Variety of connectors available.
Careful with caustic antiseptics
If meniscus moves/moved- whole cath may be contaminated
2% would reconnect
15% clean the outside and reconnect
4% would cut and reconnect
44% would clean, cut,and reconnect
35% would remove the catheter.
Disconnection
Disconnection Disconnection
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Disconnection Statlock Device
Secured to skin or epidural space?
Lockit device holds catheter securely at skin.
Reduces, but does not prevent movement-related failure
Epidural failure
125 patients with surgical epidurals 25% failed. 45% of failed due to dislodgement
Motamed, Cyrus (2006). "An analysis of postoperative epidural analgesia failure by computed tomography epidurography.". Anesthesia and analgesia 103 (4), p. 1026.
Where do catheters go?
Pull out-
Skin to epidural space distance increases when sitting lateral.
Most pronounced in obese.
Hamilton CL. Riley ET. Cohen SE. Changes in the position of epidural catheters associated with patient movement. Anesthesiology. 86(4):778-84; discussion 29A, 1997 Apr.
Our goals:
Pick a winner
Get it in
Keep it in
Make it work Respond when it goes in the wrong place
Pull it out
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Air or saline for LOR?
A 31- year old primip with L3-L4 labor epidural. 4 hours after catheter placement- constant, severe, sharp, bilateral subscapular back pain with radiation to left shoulder and arm that started acutely after pressing the PCEA button
Space Occupying Epidural Air Necessitating Emergent Caesarean Delivery. Chaim Golfeiz, Michael W. Best, Manuel C. Vallejo. BJA Aug 14, 2013
Why do they stop working? Why do they stop working?
101 parturients studied 20 % required conversion to general anesthesia. Reasons for failure:
Younger parturient age (P = 0.014) higher pre-pregnancy weight (P = 0.019) Higher weight at the end of pregnancy (P = 0.003) higher body mass index (P = 0.0004) gestational week (P = 0.008) number of top-ups (P = 0.0004) visual analog scale (VAS) score 2 h before CS (P = 0.03).
Acta Anaesthesiologica Scandinavica. 50(7):793-7, 2006 Aug.
What if it’s “iffy”?
Important to calculate depth in epidural space.
For patchy block, add bolus; if no relief, withdraw catheter 1cm
Maintain at least 3 cm in space for multi; at least 2 cm for single orifice.
Our goals:
Pick a winner
Get it in
Keep it in
Make it work
Respond when it goes in the wrong place
Pull it out
Intravenous Placement
Lateral situation?
Collapsible- test passive aspiration
Appropriate to withdraw, flush, salvage
Expand space- 2% vs. 16% incidence of venous placement Evron, et al. A & A. 2007;105(2)460.
Pre-flushed catheter- takes 2x as long to identify IV placement Bell, O'Connor & Leslie.. Anaesthesia & Intensive Care. 35(6):932-8,
2007
Unintentional IV Injection
HR 20-30 bpm (epinephrine)
Patient complaints:
“ringing” in the ears
dizziness
tinnitus
circumoral numbness
*Initial study used non pregnant patients
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Speaking of Intravenous Placement… test dose
Isoproterenol to avoid α- effect of epi
HR response non-specific in labor
Careful about multiple repeats
With dilute solutions following CSE, test for IT placement only
T-wave changes
Speaking of Intravenous Placement… test dose
Meniscus test Inject air, then saline Hold catheter up Dropping meniscus = epidural placement
Hold catheter down Continuing flow = subarachnoid or vein Return of bubbles + outflow that stops =
epidural
Bosseau Murray W. Trojanowski A. A nonpharmacological three-step test for confirmation of correct epidural catheter placement. Anesthesia & Analgesia. 87(5):1216-7, 1998 Nov
Where do catheters go?
Subdural- high, patchy block, horner’s syndrome; multi-compartmental catheter
Subdural catheter- Railroad Tracks
Subdural catheter-Railroad Tracks
Characteristics of Subdural placement Regional Anesthesia and Pain Medicine January-February 2009
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Characteristics of Subdural placement Regional Anesthesia and Pain Medicine January-February 2009
Characteristics of Subdural placement
Excessive spread of block with: Slow onset > 20 min.
CV instability
Motor sparing with sensory block
Patchy/asymetrical block
Respiratory failure
Facial/head involvement
Hoftman NN, Ferrants MF. Diagnosis of Unintentional Subdural Anesthesia/Analgesia: Analyzing RadiographicallyProven Cases to Define the Clinical Entity and to Develop a Diagnostic Algorithm. Reg Anesth Pain Med 2009;34(1):12-16.
Where do catheters go?
Through dura
Contrary to intuition, CSE does not increase subdural placement.
100 patients; eposcan vs. conventional touhy. No dural puncture of catheter
Browne IM. Birnbach DJ. Stein DJ. O'Gorman DA. Kuroda M. A comparison of Espocan and Tuohy needles for the combined spinal-epidural technique for labor analgesia. Anesthesia & Analgesia. 101(2):535-40, table of contents, 2005
Where do catheters go?
Subarachnoid Portex Arrow
Intact dura 0/300 0/300
Occult 17ga hole
1/14 0/15
Obvious 17ga hole
6/33 1/35
25ga CSE 0/90 0/90
Angle PJ. Kronberg JE. Thompson DE. Duffin J. Faure P. Balasubramaniam S. Szalai JP. Cromwell S. Epidural
catheter penetration of human dural tissue: in vitro investigation. Anesthesiology. 100(6):1491-6, 2004 Jun.
Where do catheters go?
Subarachnoid
Decision tree- thread catheter
Anesthesiology. 101(6):1422-7, 2004 Dec.
Pro Con
Unpredictable Danger of misuse Above L3? Infection and injection CES
Effective Avoid risk of 2nd dural puncture Prevent PDPH Obese pt- dependable for C/S
Subarachnoid catheter; What next?
Survey in UK. 176 units. 144 of which have written guidelines
28% place catheter, 31% give option]
Rationale: avoid potential for additional dural puncture and provide immediate analgesia
71%: EBP only after conservative measures fail for PDPH
Baraz R. Collis RE. The management of accidental dural puncture during labour epidural analgesia: a survey of UK practice. Anaesthesia. 60(7):673-9, 2005
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Where do catheters go?
Subarachnoid Catheter vs. PDPH
Efficacy increases with duration left inStrategy PD PH
IncidenceReplaceepidural
80%
IT catheter,rem oved @
delivery30%
IT catheter,left for 24
hours3%
Ayad S. Demian Y. Narouze SN. Tetzlaff JE. Subarachnoid catheter placement after wet tap for analgesia in labor: influence on the risk of headache in obstetric patients. Regional Anesthesia & Pain Medicine. 28(6):512-5, 2003 Nov-Dec.
Responding to Problems
Intrathecal “epidural” catheter
intrathecal injection possibly 200 mg of lidocaine and 61 mg of bupivacaine
apnea and fixed dilated pupils
20ml cerebrospinal fluid was replaced with 10 mL of NS and 10 mL of LR
Spontaneous respiration 5 min later, extubated in 30 min. No deficits or PDPH
Responding to Problems
Inadvertant intrathecal drugs (bupivacaine, lido, chloroprocaine) all associated with cauda equina syndrome.
Immediate injection of 10ml PF saline will help to dilute and has been shown to decrease incidence of subsequent PDPH.
Inadvertent subarachnoid injection
Tsui, Ban C. H. MD, MSc, FRCP(C)*; Malherbe, Stephan MB, ChB, MMed, FCA(SA)*; Koller, John MD, FRCP(C)*; Aronyk, Keith MD, FRCS(C)† Anesthesia & Analgesia (2004) 98(2) 434-43Reversal of an Unintentional Spinal Anesthetic by Cerebrospinal Lavage
Ferayan AA, Russell NA, Wohaibi MA, et al. Cerebrospinal fluid lavage in the treatment of inadvertent intrathecal vincristine injection. Childs Nerv Syst 1999; 15: 87–9
Charsley MM, Abram SE. The injection of intrathecal normal saline reduces the severity of postdural puncture headache. Reg Anesth Pain Med 2001; 26: 301–5.
Our goals:
Pick a winner
Get it in
Keep it in
Make it work
Respond when it goes in the wrong place
Pull it out
What goes up must come down; what goes in...
Removal complications
Arrow catheter stretches significantly more and breaks at lower weight than nylon
Asai T, Yamamoto K, Hirose T, Taguchi H, et al. Breakage of epidural catheters: a comparison of an arrow reinforced catheter and other nonreinforced catheters. Anesth Analg 2001; 92: 246–8
Soft catheters appear in numerous case reports lodged/unable to be removed
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Reinforced wire catheter problems
Catheter stuck.
Patient placed into the left lateral decubitus position and the catheter was removed without difficulty.
However, it was noted that the catheter reinforcing wire had become uncoiled at the distal end and remained inside the patient
The wire was successfully withdrawn with steady traction
Bastien JL. McCarroll MG. Everett LL. Uncoiling of Arrow Flextip plus epidural catheter reinforcing wire
during catheter removal: an unusual complication. Anesthesia & Analgesia. 98(2):554- 5, 2004
What goes up must come down; what goes in…???
Wires uncoil
What goes up must come down; what goes in...
Inadvertant intrathecal placement, with inability to remove catheter immediately after placement.
Epidural placement with immediate attempt to withdraw, but unable.
Catheter left in place for 3 days, with daily attempts to remove, until finally removed
Asai T. Shingu K. Advantages and disadvantages of the Arrow FlexTip Plus epidural catheter. Anaesthesia. 56(6):606, 2001
What goes up must come down; what goes in...
Patient in lateral position for withdrawal. Resistance felt before catheter broke without any significant stretching.
Ugboma S. Au-Truong X. Kranzler LI. Rifai SH. Joseph NJ. Salem MR. The breaking of an intrathecally-placed epidural catheter during extraction. Anesthesia & Analgesia. 95(4):1087-9, table of contents,
Allowed the patient to relax for 3 hours, placing the patient in the lateral decubitus position, and placing continuous tension on the catheter itself so as to let it "work its way out".
Pierre HL. Block BM. Wu CL. Difficult removal of a wire-reinforced epidural catheter Journal of Clinical Anesthesia. 15(2):140-1, 2003 Mar.
What goes up must come down; what goes in...
Catheter began to distort at 7cm
Small incision, grasped at 6cm
Had pt twist her hips
Asai T. Sakai T. Murao K. Kojima K. Shingu K. More difficulty in removing an arrow epidural catheter. Anesthesia & Analgesia. 102(5):1595-6, 2006 May.
What goes up must come down; what goes in…???
Case reports: Catheter placed intrathecally; inability to remove
immediately
Catheter placed normally; inability to withdraw for depth immediately Difficulty persisted for 3 days until finally removed
Catheter pulled with hemostat- broke at grip site
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Measures to remove entrapped catheter
Don’t force Gently tighten knot Lateral position or same as insertion Don’t use instruments Give “rest time” (hours or days) Steady, progressive traction Injection of saline to R/O knot GA with muscle relaxants
Arrow Flex-tip catheter
Summary
In spite of safety with regional techniques, proper placement of epidural catheters can be challenging, even in cases of uneventful insertion.
Avoid complications Distend space with saline Lateral position/soft tip to reduce vein cannulation CSE for placement verification Limit insertion depth
Secure to non-moveable anchor, but not before soft tissue shifts Recognize limitations of test doses/Every dose is a “test dose” Intrathecal placement now more commonly left in place instead
of replaced
Summary
Soft catheters reduce intravascular placement and paresthesias, but are more likely to become lodged and subsequently break
High index of suspicion for catheter failure break-through pain/spotty block Lots of top-up doses Large patient size
Lodged catheters should be removed conservatively Lateral position Gentle, steady pressure Position change Saline injection