Epidural anaesthesia for regional blocks

Epidural Anaesthesia

1. EPIDURAL ANAESTHESIA /ANALGESIA
INTRODUCTION
HISTORY
ANATOMY
INDICATIONS
CONTRAINDICATIONS
EQUIPMENT
DRUGS
TECHNIQUES
COMPLICATIONS

2. INTRODUCTION
INVOLVES BOLUS INJECTION ( DOCTOR/NURSE/ PCA)
INFUSION INTO THE EPIDURAL SPACE OF
•LOCAL ANAESTHETICS
•OPIOIDS
•ACETYLCHOLINESTERASE INHIBITORS
•ALPHA2 ADRENERGIC AGONISTS
•STEROIDS

3. HISTORY
1902 CAUDAL APPROACH JEAN SICARD/FERNAND
CATHELIN (INDEPENDENTLY)
1921 LUMBAR APPROACH FIDEL PAGES MIRAVE (SPANISH
MILITARY SURGEON
1920’S-1930 ACHILLE DOGLIOTI (LOR &HANGING DROP)
&CORNING
1956 J.BONICA PARAMEDIAN APPROACH

4. ANATOMY EPIDURAL SPACE BOUNDARIES
SUPERIORLY: FORAMEN MAGNUM
INFERIORLY: SACROCOCCYGEAL MEMBRANE OF THE SACRAL CANAL.
INTERNALLY:DURA MATER OF THE SPINAL CORD
EXTERNAL:
•POSTERIOR:LIGAMENTUM FLAVA & PERIOSTEUM LINING VERTEBRAL
CANAL
•ANTERIOR: POSTERIOR LONGITUDINAL LIGAMENT
•LATERERALLY: INTERVERTEBRAL FORAMINA

6. CONTENTS
•EPIDURAL FAT
•EPIDURAL VEINS ( BASTON’S PLEXUS)
•LYMPHATICS
•SPINAL NERVE ROOTS
•CONNECTIVE LAYERS DEMONSTRATED BY
RADIOLOGY

7. SHAPE:
VERTEBRAL CANAL DEEPEST IN THE LUMBAR REGION
TRIANGULAR IN CROSS -SECTION IN LUMBAR REGION
BASE OF TRIANGLE IS ANTERIOR
NARROW POSTERIORLY
DISTANCE BETWEEN SKIN AND EPIDURAL 2 -9 CM

8. NEEDLE PASSAGE MEDIAN ROUTE
1 SKIN
2 SUBCUTANEOUS TISSUES
3 SUPRASPINOUS LIGAMENTS ( (FROM C7) SPINAL TIPS
TO SACRUM)
4 INTERSPINOUS LIGAMENT (BETWEEN SPINOUS
PROCESSES)
5 LIGAMENTUM FLAVUM ( BETWEEN LAMINAE)
6 EPIDURAL SPACE

9. INDICATIONS
OPERATIVE ANAESTHESIA ( LAPAROTOMY/LOWER LIMBS/
OBSTETRICS/THYROIDECTOMY/CAROTID SURGERY)
OPERATIVE ANALGESIA
LABOUR ANALGESIA
CHEST TRAUMA
CHRONIC PAIN SYNDROMES

10. CONTRAINDICATIONS
PATIENT REFUSAL
COAGULOPATHIES
LOW DOSE HEPARIN ( AFTER 6 HRS)/LOW MOLECULAR WEIGHT
HEPARINS (AFTER 12HRS)
INFECTION BOTH GENERALISED AND LOCAL
HYPOVOLAEMIC/SHOCK ( THREATENING SHOCK)
NEUROLOGICAL DISEASE (RAISED ICP/FEAR OF WORSENING A
NEUROLOGICAL DISEASE)
PREVIOUS SPINAL SURGERY (?)
ASPIRIN (?) IN COMBINATION WITH OTHER ANTIPLATELET DRUG
CLOPIDOGREL ( DISCONTINUE FOR 3 -5 DAYS

11. EQUIPMENT
STERILE PACK
STERILE ,GOWN , GLOVES AND MASK (STRICT ASEPSIS)
LOCAL ANAESTHETIC (LIDOCAINE) FOR INFILTRATION
16-19G TUOHY NEEDLES WITH STYLET(FOR CATHETER
INSERTION) 25G FOR CHILDREN
MARKED AT 1 CM INTERVALS (LEES MARKINGS) AND WINGED
CRAWFORD NEEDLE ( STRAIGHT TIP OBLIQUE BEVEL)
LOSS OF RESISTANCE SYRINGE ( FOR AIR OR SALINE)
COLLAPSING DRUMS OR BALLOONS (MACINTOSH’S)

14. DRUGS
BUPIVACAINE HCL1963 (RACEMIC MIXTURE L &D -ISOMERS)
MAX SAFE DOSE 2MG/KG.
LEVOBUPIVCAINE 1997(PURE L ENANTIOMER OF BUPIV.
REDUCED CVS AND CNS TOXICITY)
LIDOCAINE HCL 1947
PRILOCAINE (1959 AMIDE SLOWER THAN LIDO BUT ACTS
LONGER)
ROPIVACAINE 1997 ( BUPIV BUTYL/REPLACED BY PROPYL
LESS TOXIC SAFER)
ETIDOCAINE 1972 ( DERIVA . LIDOCAINE. RAPID ONSET BUT
LONG AS BUPIV )
CHLORPROCAINE HCL1952( ESTER RAPID ONSET SHORT
ACTION 45 MINS

15. EPIDURAL AND SPINAL OPIOIDS
DRUG. EPID. SPINAL. DURATION HRS
FENTA 50-100(mcg). 10-25(mcg). 2-4hrs
MORPH. 1-8 MG. 100-400 (mcg). 12-18 hrs
DIAMORPH. 1-5MG. 100-300(mcg). 6-8 hrs
PETHIDINE. 25-100MG. 10-100 MG. 6-8 HRS

16. BUPIVACAINE
ANAESTHESIA 0.25-0.75% ONSET 15-30 MINS.LASTS 1.5 TO 2.5
HRS
10-20 ML LUMBAR BLOCKADE
(1.5 ML PER SEGMENT OVER 50 YRS
IN PREGNANCY 1 ML. PER SEGMENT
OVER 80 YRS 0.75 MLS PER SEGMENT
ANALGESIA 0.8-0.1% WITH FENTANYL 2-4 MCG/ML AT 10-20 ML
PER HOUR ALLOWS MOBILITY
THORACIC 3-5 ML BLOCKS 2-4 SEGMENTS
CERVICAL BLOCK 6-8 ML

17. LIDOCAINE
ANAESHESIA 2% ONSET 5-15 MINS LASTS1-1.5 HRS ( IF
1.200,000 ADRENALINE ADDED
ALKALINISATION LEADS TO FASTER ONSET AND DENSER
BLOCK
RARELY USED FOR ANALGESIA

18. ROPIVACAINE HCL
PROPYL GROUP REPLACING BUTYL GROUP IN
BUPIVACAINE
S-ENANTIOMER
LESS LIPID SOLUBLE SO LESS TOXIC
LESS TOXIC TO CNS AND CVS
LESS POTENT THAN BUPIVACAINE
VASOCONSTRICTIVE
0.2%-1 % SOLUTIONS

19. ETIDOCAINE HCL
DERIVED FROM LIGNOCAINE
RAPID ONSET/LONG ACTING LIKE BUPIVACAINE
MOTOR BLOCK MAY EXCEED SENSORY BLOCK
USED AS 1-1.5 % SOLUTIONS
MAXIMUM SAFE DOSE 2 MG/KG

20. CHLOROPROCAINE HCL
ESTER LA,WITH RAPID ONSET SHORT DURATION (45
MINS)
LOW SYSTEMIC TOXICITY
HYDROLYSED BY PLASMA CHOLINESTERASE
2-3 % SOLUTIONS MAX SAFE DOSE 15 MG/KG
USED IN USA AND SOME EUROPEAN COUNTRIES
FOR EPIDURAL ANALGESIA/ANESTHESIA

21. FACTORS AFFECTING HEIGHT OF
BLOCK
SITE OF INSERTION
HEIGHT OF THE PATIENT
AGE OF THE PATIENT (LESS LEAKAGE WITH AGE)
VOLUME OF THE SOLUTION
VOLUME OF EPIDURAL SPACE (DECREASED IN
PREGNANCY DUE TO ENGORGED EPIDURAL VEINS

22. EPIDURAL OPIOIDS1
BIND TO OPIOID RECEPTORS IN SUBSTANTIA
GELATINOSA
PROFOUND LONG LASTING ANALGESIA
LACK SYMPATHETIC,MOTOR,SENSORY BLOCKADE
ONSET DETERMINED BY LIPID SOLUBILITY (HIGHER LIPID
SOLUBILITY THE FASTER THE ONSET BUT SHORTER
ACTING)
COMBINATION WITH LOCAL ANAESTHETICS
SYNERGISTIC

23. EPIDURAL OPIOIDS 2
OPIOIDS MIXED WITH LA’S (BUPIVACAINE/FENTANYL OR
DIAMORPHINE 50-100 MCG ML AT 5-15 ML/HR) FOR POST
OP PAIN OR CHRONIC PAIN
SUFENTANIL IS USED MORE IN USA
EPIDURAL INFUSIONS OF OPIOIDS RARELY USED ALONE:
DIAMORPHINE 0.25-2 MG HR MORPH 0.5 MG HR
FENTANYL40-100 MCG HR SUFENTANIL 20-50MCG HR
PETHIDINE 10-15 MG ( HAS LA PROPERTIES )
MORPHINE SULPHATE PENTAHYDRATE..EXTENDED
RELEASE (ENCAPSULATED IN LIPOSOMES 20 MIC M
ONSET 3 HRS LASTS 48 HRS

24. TECHNIQUES OF INSERTION
POSITIONS:SITTING OR SUPINE LATERAL
FULL ASEPTIC TECHNIQUE
APPROACH:MEDIAN OR PARAMEDIAN (LATTER LESS
CHANCE OF DURAL/BLOOD VESSEL PUNCTURE EASIER
IN ELDERLY
DEEP AND SUPERFICIAL INFILTRATION
INSERTION OF 16-18 G WINGED TUOHY NEEDLES HELD
BY LIGAMENTUM FLAVUM
NEEDLE INSERTION BEVEL LAT VS CRANIALLY

25. LOCATION EPIDURAL SPACE
NEGATIVE PRESSURE IN THE EPIDURAL SPACE SEVERAL
POSTULATES.
LOSS OF RESISTANCE AIR/SALINE ( WITH LOW
RESISTANCE SYRINGE) USING INTERMITTENT OR
CONSTANT PRESSURE
HANGING DROP TECHNIQUE
COLLAPSING DRUM OR BALLOON ( MACINTOSH
SPRING LOADED PLUNGERS

26. CATHETER INSERTION
16-18 G CATHETER INSERTED SMOOTHLY (BEYOND 20 CM)
NEEDLE WITHDRAWN OVER CATHETER
3-5 CM LEFT IN SPACE
ATTACHED TO 0.2 MICRO/M BACTERIAL FILTER
PROBLEMS:
BLOOD IN CATHETER…..WITHDRAW AND FLUSH
UNABLE TO ADVANCE…ADJUST NEEDLE OR STRAIGHTEN
PATIENTS LEGS, INJECTION OF SALINE 5-10 ML

27. COMPLICATIONS 1
NEEDLE/CATHETER COMPLICATIONS;
BRUISING ,
BLOODY TAP, EPIDURAL VEIN PUNCTURE
EPIDURAL HAEMATOMA (RARE) ,
NEUROLOGICAL DAMAGE (RARE),
DURAL TAP (SPINAL HEADACHE)
SHEARING OF CATHETER OR KNOTTING
DRUG INJECTION COMPLICATIONS :

28. COMPLICATIONS 2
•PATCHY BLOCKS ( PARTIAL SUBARACHNOID/SUBDURAL PLACEMENT)
•CATHETER MIGRATION
•ISOLATED CRANIAL NERVE PALSIES(5 AND 6 TH CRANIAL NERVES)
•NERVE DAMAGE ( DUE TO INJECTION OF WRONG DRUGS)
•SHIVERING (TREATED WITH SMALL DOSES OF TRAMADOL OR PETHDINE)
•NAUSEA ( TREATED WITH ONDASETRON/ANTIEMETICS