Transcript Spinal - Epidural - [Combined Spinal Epidural]
Spinal Anesthesia
Donald H. Lambert Boston, Massachusetts
http://www.debunk-it.org
www.debunk-it.org
RULE N0. 1: YOUR ATTENDING IS ALWAYS RIGHT.
RULE NO. 2: IF YOUR ATTENDING IS WRONG, SEE RULE NO. 1.
Spinal Anesthesia
Advantages v. Disadvantages Indications and Contraindications Positioning Getting ready Getting the needle in the right spot Baricity Dosing What to inject Addition of a vasoconstrictor Addition of narcotics Complications (and how to avoid them)
Advantages of Spinal Anesthesia
Technically easy Objective end-point Rapid onset Profound sensory and motor block Low potential for systemic toxicity
Disadvantages of Spinal Anesthesia
Limited duration Limited sensory and motor separation “Hypotension” Potential neuro-toxicity Headache
Spinal Anesthesia
Advantages v. Disadvantages Indications and Contraindications Positioning Getting ready Getting the needle in the right spot Baricity Dosing What to inject Addition of a vasoconstrictor Addition of narcotics Complications (and how to avoid them)
Indications
Any operation in the lower abdomen and below
Absolute Contraindications
Patient refusal Uncorrected hypovolemia Uncorrected coagulopathy Infection at site of injection Increased intracranial pressure
Relative Contraindications
Some neurologic diseases Bacteremia Deformities that preclude doing an LP easily
Spinal Anesthesia
Advantages v. Disadvantages Indications and Contraindications Positioning Getting ready Getting the needle in the right spot Baricity Dosing What to inject Addition of a vasoconstrictor Addition of narcotics Complications (and how to avoid them)
Positioning for the Lumbar Puncture
Two choices Sitting Lateral decubitus (recumbent)
Spinal Anesthesia
Advantages v. Disadvantages Indications and Contraindications Positioning Getting ready Getting the needle in the right spot Baricity Dosing What to inject Addition of a vasoconstrictor Addition of narcotics Complications (and how to avoid them)
Spinal Anesthesia
Advantages v. Disadvantages Indications and Contraindications Positioning Getting ready Getting the needle in the right spot Baricity Dosing What to inject Addition of a vasoconstrictor Addition of narcotics Complications (and how to avoid them)
Getting the needle in the right spot
•
What is the object of the game of basketball?
•
Get the ball in the hoop (Red Aurbach).
•
What are we trying to do with spinal anesthesia?
•
Get the needle into the CSF.
Spinal Anesthesia
Advantages v. Disadvantages Indications and Contraindications Positioning Getting ready Getting the needle in the right spot Baricity Dosing What to inject Addition of a vasoconstrictor Addition of narcotics Complications (and how to avoid them)
Baricity
The density of the local anesthetic solution in relation to the density of the CSF More dense than CSF hyperbaric sinks Same density as CSF isobaric stay where it is injected (relatively) Less dense than CSF hypobaric floats
Spinal Anesthesia
Advantages v. Disadvantages Indications and Contraindications Positioning Getting ready Getting the needle in the right spot Baricity Dosing What to inject Addition of a vasoconstrictor Addition of narcotics Complications (and how to avoid them)
Spinal Anesthesia
Dosing will affect Spread Duration Quality of Anesthesia That is, the need for supplemental IV medication
The dosing in this study was 10 mg, 15 mg, and 20 mg of bupivacaine The lowest dose limited spread The lowest dose also resulted in more failures than the higher doses.
Spinal Anesthesia
Advantages v. Disadvantages Indications and Contraindications Positioning Getting ready Getting the needle in the right spot Baricity Dosing What to inject Addition of a vasoconstrictor Addition of narcotics Complications (and how to avoid them)
.
Agent Proc.
Chlorop.
Lido.
Mep.
Prilo.
Ropiv.
Dibu.
Bupiv.
Tetra.
Spinal Anesthesia Agents
Conc. (%) 10 2 1.5 – 5 4 ?
?
0.06-0.5
0.25-.75
0.25-1 Dose 100-200 40-120 30-100 40-80 ?
?
2.5-12 5-22.5
5-20 Gluc. Duration 7.5
9 ?
?
5 8.25
5 30-90 30-90 30-90 30-90 ?
?
75-150 75-150 75-150
Hyperbaric Isobaric
Dosing Guidelines
Based on the spinal canal model (and many years of doing this) Hyperbaric solutions extend into the thoracic region Isobaric solution remain in the lumbar region I give hyperbaric solutions for operations above the L1 dermatome and isobaric solutions for those below
Dosing Guidelines
Hernia operations and those operations whose innervation is by nerves above L1
HYPERBARIC
Those operations whose innervation is by nerves below L1 (pretty much all lower extremity operation including hip operations)
ISOBARIC
CHOOSING A LOCAL ANESTHETIC FOR SPINAL ANESTHESIA BASE DECISION ON THE DURATION OF THE OPERATION DURATION AGENT < > 1.5 HRS 1.5 HRS PROCAINE (LIDOCAINE, ?CHLOROPROCAINE, ?ROPIVACAINE) BUPIVACAINE (TETRACAINE)
CHOOSING A LOCAL ANESTHETIC FOR SPINAL ANESTHESIA GIVE ENOUGH TO PROVIDE ADEQUATE ANESTHESIA BARICITY ISOBARIC HYPERBARIC PROC.
80 mg 80 mg LIDO.
60 mg 60 mg BUPIV.
15 mg 15 mg TETRA.
15 mg 15 mg ? CHLOROPRACAINE, ? ROPIVACAINE
Isobaric Spinal Anesthesia
Epidural Bupivacaine for spinal anesthesia is an “ off label use ” of this agent It says right on the bottle: “Not for spinal anesthesia” What is the value or wisdom behind using that agent?
It works great and I have used it since the 1980’s.
I know of no reports of complications associated with using it.
Litigation for the off-labeled use of a drug has not appeared in the ASA closed claims database.
Who would know?
Unless you wrote on your anesthesia record, “I used the bupivacaine that is not for spinal anesthesia.”
Spinal Anesthesia
Advantages v. Disadvantages Indications and Contraindications Positioning Getting ready Getting the needle in the right spot Baricity Dosing What to inject Addition of a vasoconstrictor Addition of narcotics Complications (and how to avoid them)
Spinal Anesthesia
Advantages v. Disadvantages Indications and Contraindications Positioning Getting ready Getting the needle in the right spot Baricity Dosing What to inject Addition of a vasoconstrictor Addition of narcotics Complications (and how to avoid them)
Narcotic work here in the substantia gelatinosa Local anesthetics work here in the nerve roots
Spinal Anesthesia
Addition of narcotics Fentanyl (15-25 ug lasts a few hours) Sufentanil (10 - 20 ug lasts a few hours) Morphine (100 - 200 ug lasts 12-24 hours) Side effects (increase with increasing dose) Nausea and vomiting Itching Respiratory depression
Spinal Anesthesia
Advantages v. Disadvantages Indications and Contraindications Positioning Getting ready Getting the needle in the right spot Baricity Dosing What to inject Addition of a vasoconstrictor Addition of narcotics Complications (and how to avoid them)
Spinal Anesthesia
Complications Cardiac arrest Hypotension Headache Nerve injury
Cardiac Arrest Still Occurring
Editorial on Auroy’s study:
“Spinal anesthesia appears in this study to be more dangerous than other regional anesthesia techniques.”
“The risk of cardiac arrest is five- to six fold greater than with other regional anesthetic techniques ” Eisenach, James C. Regional Anesthesia: Vintage Bordeaux (and Napa Valley) Anesthesiology 1997;87:467-469
Unexpected cardiac arrest during spinal anesthesia: a closed claims analysis of predisposing factors Number of Claims Number of Arrests Mean Age ASA Physical Status 1988 900 14 (1.5%) 36 I - II 2004 5,047 68 (1.3%) 42 I - II
Caplan, R A; et al. Unexpected cardiac arrest during spinal anesthesia: a closed claims analysis of predisposing factors. Anesthesiology 1988;68:5-11 Caplan, R A; et al. Injuries Associated with Regional Anesthesia in the 1980s and 1990s: A Closed Claims Analysis. Anesthesiology. 2004;101:143-152
Unexpected cardiac arrest during spinal anesthesia: a closed claims analysis of predisposing factors Local Anesthetic Tetracaine Dose Maximum Level Time of Arrest 6 - 14 mg T4
12 -
78 minutes
Caplan, R A; et al. Unexpected cardiac arrest during spinal anesthesia: a closed claims analysis of predisposing factors. Anesthesiology 1988;68:5-11
Unexpected cardiac arrest during spinal anesthesia: a closed claims analysis of predisposing factors
Factors Predisposing to Asystole High level Loss of Cardiac Sympathetic Stimulation Unopposed Vagal Tone Decreased Venous Return Empty Left Ventricle Activation of Intracardiac Reflexes ? So-called Bezold-Jarisch Reflex ? So-called Vaso-vagal Syncope
Caplan, R A; et al. Anesthesiology 1988;68:5-11 and Mackey, D C, et al. Anesthesiology 1989;70:866-868
Cardiac arrest during spinal anesthesia
How can this be prevented and/or treated?
Maintain venous return at all cost Use epinephrine at the first sign of cardiac arrest
Keats, A. S. Anesthesia mortality--a new mechanism.
Anesthesiology 1988;68:2-4.
Cardiac Arrest Associated with Anesthesia (per 10,000)
Author Aromaa Auroy Biboulet Auroy Sprung Kopp Year 1997 1997 2001 2002 2003 2005 Spinal 0.04
6.4
6.5
2.7
1.5* 2.9
Epidural 0 0.98
0 0 N/A 0.9
General N/A N/A 0.8
N/A 5.5
29 cases * ”Regional Anesthesia”
Cardiac Arrest Associated with Anesthesia
There appears to be two mechanisms for cardiac arrest during spinal anesthesia Spinal factors Vaso-depressor syncope Factors other than the spinal Blood loss Cardiac events Orthopedic manipulations
Spinal Anesthesia
Complications Cardiac arrest Hypotension Headache Nerve injury
Spinal Anesthesia Complications
Hypotension (happens!)
Spinal Anesthesia
Complications Cardiac arrest Hypotension Headache Nerve injury
The Two Components of Spinal Headache
There must have been a lumbar puncture The headache is related to posture Worst when standing or sitting Gone or improved with recumbence
Effect of Age on the Incidence of Spinal Headache
16 14 12 10 8 6 4 2 0 10-19 20-29 30-39 40-49 Age 50-59 60-69 70-79 80-89 Vandam and Dripps JAMA 1956;161:586-591
Effect of Needle Gauge on the Incidence of Spinal Headache
18 16 14 12 10 8 6 4 2 0 16 19 20 Needle Gauge 22 24 Vandam and Dripps JAMA 1956;161:586-591
Spinal Anesthesia
Complications Cardiac arrest Hypotension Headache Nerve injury
Nerve Injury with Spinal Anesthesia
Two types Permanent Cauda equina syndrome Adhesive arachnoiditis Non-permanent Transient radicular irritation
Permanent Nerve Injury with Spinal Anesthesia
Lidocaine spinal anesthesia was associated with 14.4 per 10,000 neurologic complications compared to 2.2 per 10,000 for bupivacaine spinal anesthesia.
Auroy Y. et al. Major complications of regional anesthesia in France: The SOS Regional Anesthesia Hotline Service. Anesthesiology 2002; 97: 1274-80
Permanent Nerve Injury with Spinal Anesthesia
In the cases [of cauda equina syndrome and paraparesis] after subarachnoid block, hyperbaric 5% lidocaine was used in eight cases , bupivacaine 0.5% in 11 cases , and in one case a mixture of both drugs was used. Moen V. et al: Anesthesiology 2004; 101: 950-9
Major Complication of Spinal Anesthesia
Spinal is somewhat more dangerous in causing cardiac arrest and major nerve injury than epidural or general Epidural has a neurological injury rate similar to spinal but the injuries are different Epidural are associated with hematoma and compressive nerve injury (? owing to volume) Spinals are associated with local anesthetic toxicity
Permanent Nerve Injury with Spinal Anesthesia
Neurologic injury associated with paresthesia or pain on injection is believed to be traumatic .
Neurologic injury not associate with paresthesia or pain on injection is believed to be due to local anesthetic toxicity .
Nerve Injury Still Occurring
Editorial on Auroy’s study:
“Spinal anesthesia appears in this study to be more dangerous than other regional anesthesia techniques.”
“Neurologic injury is two- to threefold greater with spinal than with other regional anesthetic techniques.” Eisenach, James C. Regional Anesthesia: Vintage Bordeaux (and Napa Valley) Anesthesiology 1997;87:467-469
Non-permanent Nerve Injury with Spinal Anesthesia
Minor complications Transient neurologic symptoms (TNS) a.k.a. transient radicular irritation (TRI)
Non-permanent Nerve Injury with Spinal Anesthesia
TNS/TRI Most frequent with lidocaine (10-34% incidence) More frequent with lithotomy position and knee arthroscopy VAS pain score averages 6 out of 10 Many rate the pain worse than their incision Can last up to three days Least frequent with bupivacaine
Non-permanent Nerve Injury with Spinal Anesthesia
TNS/TRI The best alternative to lidocaine appears to be bupivacaine. Lasts too long Other shorter acting substitutes have not caught on.
Procaine, mepivacaine, prilocaine, ropivacaine
Non-permanent Nerve Injury with Spinal Anesthesia
TNS/TRI Chloroprocaine ( off label ) is being rediscovered as a short acting spinal anesthetic.
Series of ten articles by Dan Kopacz et al. in the last year (see Anesth Analg 2004 and 2005) Comparable to lidocaine.
No TNS
Non-permanent Nerve Injury with Spinal Anesthesia
TNS/TRI The spinal anesthetic profile of 40 mg chloroprocaine compares favorably with the same dose of spinal lidocaine Lidocaine was associated with mild to moderate TNS in 7 of 8 subjects No subject complained of TNS with chloroprocaine Yoos JR, Kopacz DJ:. Anesth Analg 2005; 100: 566-72
Spinal Anesthesia
Advantages v. Disadvantages Indications and Contraindications Positioning Getting ready Getting the needle in the right spot Baricity Dosing What to inject Addition of a vasoconstrictor Addition of narcotics Complications (and how to avoid them)