Donald H. Lambert Boston, Massachusetts Spinal Anesthesia.

Donald H. Lambert

Boston, Massachusetts

http://www.debunk-it.org

Spinal AnesthesiaSpinal Anesthesia

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RULE N0. 1:

YOUR ATTENDING IS ALWAYS RIGHT.

RULE NO. 2:

IF YOUR ATTENDING IS WRONG, SEE RULE NO. 1.

Spinal AnesthesiaSpinal 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 AnesthesiaAdvantages of Spinal Anesthesia

Technically easy Objective end-point Rapid onset Profound sensory and motor block Low potential for systemic toxicity

Disadvantages of Spinal AnesthesiaDisadvantages of Spinal Anesthesia

Limited duration Limited sensory and motor separation “Hypotension” Potential neuro-toxicity Headache

IndicationsIndications

Any operation in the lower abdomen and below

Absolute ContraindicationsAbsolute Contraindications

Patient refusal Uncorrected hypovolemia Uncorrected coagulopathy Infection at site of injection Increased intracranial pressure

Relative ContraindicationsRelative Contraindications

Some neurologic diseases Bacteremia Deformities that preclude doing an LP easily

Positioning for the Lumbar PuncturePositioning for the Lumbar Puncture

Two choices Sitting Lateral decubitus (recumbent)

• 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.

Getting the needle in the right spot

BaricityBaricity 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

Hyp

erbari

cIsob

aric

Hyp

obari

c


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 AgentsSpinal Anesthesia AgentsAgent Conc. (%) Dose Gluc. Duration

Proc. 10 100-200 30-90Chlorop. 2 40-120 30-90Lido. 1.5 – 5 30-100 7.5 30-90Mep. 4 40-80 9 30-90Prilo. ? ? ? ?Ropiv. ? ? ? ?Dibu. 0.06-0.5 2.5-12 5 75-150Bupiv. 0.25-.75 5-22.5 8.25 75-150Tetra. 0.25-1 5-20 5 75-150

.

Dosing GuidelinesDosing 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

Hyperbaric

Isobaric I give hyperbaric

solutions for operations above the L1 dermatome and isobaric solutions for those below

Dosing GuidelinesDosing 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 CHOOSING A LOCAL ANESTHETIC FOR SPINAL ANESTHESIASPINAL ANESTHESIA

BASE DECISION ON THE BASE DECISION ON THE DURATIONDURATION OF OF THE OPERATIONTHE OPERATION

DURATION AGENT

< 1.5 HRS PROCAINE (LIDOCAINE,?CHLOROPROCAINE,?ROPIVACAINE)

> 1.5 HRS BUPIVACAINE(TETRACAINE)

CHOOSING A LOCAL ANESTHETIC FOR CHOOSING A LOCAL ANESTHETIC FOR SPINAL ANESTHESIASPINAL ANESTHESIA

GIVE ENOUGH TO PROVIDE GIVE ENOUGH TO PROVIDE ADEQUATEADEQUATE ANESTHESIAANESTHESIA

BARICITY PROC. LIDO. BUPIV. TETRA.ISOBARIC 80 mg 60 mg 15 mg 15 mgHYPERBARIC 80 mg 60 mg 15 mg 15 mg

? CHLOROPRACAINE, ? ROPIVACAINE

Isobaric Spinal AnesthesiaIsobaric 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.”

Narcotic work here in the substantia gelatinosa

Local anesthetics work here in the nerve roots


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


Complications Cardiac arrest Hypotension Headache Nerve injury

Eisenach, James C. Regional Anesthesia: Vintage Bordeaux (and Napa Valley)

Anesthesiology 1997;87:467-469

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 ”

Cardiac Arrest Still OccurringCardiac Arrest Still Occurring

Unexpected cardiac arrest during spinal anesthesia: a closed claims analysis of predisposing factors

1988 2004

Number of Claims 900 5,047

Number of Arrests 14 (1.5%) 68 (1.3%)

Mean Age 36 42

ASA Physical Status I - II 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


Local Anesthetic Tetracaine

Dose 6 - 14 mg

Maximum Level T4

Time of Arrest 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


Caplan, R A; et al. Anesthesiology 1988;68:5-11 and Mackey, D C, et al. Anesthesiology 1989;70:866-868

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

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.

Author Year Spinal Epidural GeneralAromaa 1997 0.04 0 N/AAuroy 1997 6.4 0.98 N/ABiboulet 2001 6.5 0 0.8Auroy 2002 2.7 0 N/ASprung 2003 1.5* N/A 5.5Kopp 2005 2.9 0.9 29 cases

* ”Regional Anesthesia”

Cardiac Arrest Associated with AnesthesiaCardiac Arrest Associated with Anesthesia(per 10,000)(per 10,000)

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

Cardiac Arrest Associated with AnesthesiaCardiac Arrest Associated with Anesthesia

Spinal Anesthesia ComplicationsSpinal Anesthesia Complications

Hypotension (happens!)

Incidence and risk factors for side effects ofspinal anesthesia in 952 patients

Hypotension in 314 (33%)

Bradycardia in 125 (13%)

Nausea in 175 (18%)

Vomiting in 65 (7%)

Dysrhythmia in 20 (2%)

Carpenter, RL, et al. Anesthesiology 1992;76:906

Reduction of side effects during spinalanesthesia

Minimize peak block height

Perform lumbar puncture at or below L3-L4

Avoid vasoconstrictors

Avoid procaine

Carpenter, RL, et al. Anesthesiology 1992;76:906

The Two Components The Two Components of Spinal Headacheof 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 Effect of Age on the Incidence of Spinal Headacheof Spinal Headache

Vandam and Dripps JAMA 1956;161:586-591

0

2

4

6

8

10

12

14

16P

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10-19 20-29 30-39 40-49 50-59 60-69 70-79 80-89

Age

Effect of Needle Gauge on the Effect of Needle Gauge on the Incidence of Spinal HeadacheIncidence of Spinal Headache

Vandam and Dripps JAMA 1956;161:586-591

02468

1012141618

Per

cent

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16 19 20 22 24

Needle Gauge

Two types Permanent

Cauda equina syndrome Adhesive arachnoiditis

Non-permanent Transient radicular irritation

Nerve Injury with Spinal AnesthesiaNerve 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 Permanent Nerve Injury with Spinal AnesthesiaAnesthesia

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


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

Major Complication of Spinal AnesthesiaMajor Complication of 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.


Eisenach, James C. Regional Anesthesia: Vintage Bordeaux (and Napa Valley)

Anesthesiology 1997;87:467-469

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.”

Nerve Injury Still OccurringNerve Injury Still Occurring

Minor complications Transient neurologic symptoms (TNS) a.k.a. transient

radicular irritation (TRI)

Non-permanent Nerve Injury with Non-permanent Nerve Injury with Spinal AnesthesiaSpinal Anesthesia

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

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

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

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

TNS/TRI


Unanswered questions are better Unanswered questions are better than unquestioned answers!than unquestioned answers!

Questions?Questions?

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Donald H. Lambert Boston, Massachusetts Spinal Anesthesia.

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