1. 11
The choice of anaesthetic inThe choice of anaesthetic in
primary total hip replacementprimary total hip replacement
surgery – which gives the bestsurgery – which gives the best
perioperative outcome?perioperative outcome?
2. 2
OverviewOverview
Definition of GA and RADefinition of GA and RA
Anaesthetic options for primary THRAnaesthetic options for primary THR
RA vs GARA vs GA
Factors affecting choice ofFactors affecting choice of
anaestheticanaesthetic
ConclusionConclusion
3. 3
DefinitionsDefinitions
General AnaesthesiaGeneral Anaesthesia
Absence of cerebral response to noxiousAbsence of cerebral response to noxious
stimulation by means of drugs, usuallystimulation by means of drugs, usually
given via IV or inhalational routegiven via IV or inhalational route
Regional AnaesthesiaRegional Anaesthesia
Selective denervation of part of the bodySelective denervation of part of the body
by administration of local anaestheticsby administration of local anaesthetics
around the nervearound the nerve
Ref 6
4. 4
Anaesthetic Options for 1Anaesthetic Options for 1oo
THRTHR
GAGA
RA (+/- sedation)RA (+/- sedation)
• Spinal - single shot (or continuous)Spinal - single shot (or continuous)
• Epidural – continuous (or single shot)Epidural – continuous (or single shot)
• Combined spinal epiduralCombined spinal epidural
• Lumbar and sacral plexus blocks - single shotLumbar and sacral plexus blocks - single shot
(with/without catheter)(with/without catheter)
Combination of GA/RACombination of GA/RA
Ref 7
5. 5
DVT 2
PE 2
BTR 9
OR of 1 = No
difference in odds of
DVT/PE/BTR*
between RA and GA
Increasing protective effect of
RA on DVT/PE incidence and BTR
*BTR = Blood
Transfusion
Requirement
2
Meta-analysis of
Spinal or Epidural
vs GA
9
Spinal vs GA
Clinical Advantages of RA (1)Clinical Advantages of RA (1)
6. 6
Reduced intra-operative blood lossReduced intra-operative blood loss
• 275ml/case (95% CI 180-371 ml)275ml/case (95% CI 180-371 ml) 22
Better immediate postoperativeBetter immediate postoperative
analgesiaanalgesia 44
• Pre-requisite for successful rehabilitationPre-requisite for successful rehabilitation 88
2
Spinal or Epidural vs GA 4
Spinal vs GA
Clinical Advantages of RA (2)Clinical Advantages of RA (2)
7. 7
Advantages of RA (3)Advantages of RA (3)
Reduced total cost per caseReduced total cost per case 44
• Less cost for anaesthesia (p<0.01)Less cost for anaesthesia (p<0.01)
• Less cost for recovery (p<0.05)Less cost for recovery (p<0.05)
Patients regain mental acuity quickerPatients regain mental acuity quicker 1010
Fewer drugs usedFewer drugs used
4
Spinal vs GA
8. 8
Disadvantages of RADisadvantages of RA 22
Takes longerTakes longer
Failure of blockFailure of block GAGA
Urinary retentionUrinary retention
Potential for CVS instabilityPotential for CVS instability
X
9. 9
Advantages of GAAdvantages of GA 11,1511,15
Faster techniqueFaster technique
Patient preference to not be awakePatient preference to not be awake
10. 10
Disadvantages of GADisadvantages of GA 1111
Slower recovery from sedationSlower recovery from sedation
Increased post op respiratory infectionIncreased post op respiratory infection
Requires immediate post opRequires immediate post op
sedative/analgesiasedative/analgesia
Increased post op nauseaIncreased post op nausea
X
11. 11
Choice of anaestheticChoice of anaesthetic
Co-morbiditiesCo-morbidities
Anaesthetic HistoryAnaesthetic History
DrugsDrugs
AllergiesAllergies
AirwayAirway
12. 12
ConclusionConclusion
Evidence that RA better perioperativeEvidence that RA better perioperative
outcome:outcome:
• Lower DVT/PELower DVT/PE
• Reduced blood transfusion requirementReduced blood transfusion requirement
• Better post-operative analgesiaBetter post-operative analgesia
Choice of anaesthetic depends onChoice of anaesthetic depends on
many factors and alters with eachmany factors and alters with each
patientpatient
13. 13
ReferencesReferences
1. National Joint Registry “National Joint Registry Annual Report 2005-2006”, downloaded from www.njrcentre.org.uk, on 18th
July 2007.
2. Mauermann WJ, Shilling AM, Zuo Z “A comparison of neuraxial block versus general anesthesia for elective total hip
replacement: A meta-analysis” Regional Anesthesia (2006) 103:1018-1025.
3. Rodgers A, Walker N, Schug S, McKee A, Kehlet H, van Zunderet A, Sage D, Futter M, Saville G, Clark T, MacMahon S
“Reduction of postoperative mortality and morbidity with epidural or spinal anaesthesia: results from overview of
randomised trials” BMJ (2000) 321:1-12.
4. Gonano C, Leitgeb U, Sitzwohl C, Ihra G, Weinstabl C, Kettner SC “Spinal versus General Anaesthesia for Orthopaedic
Surgery: Anaesthesia Drug and Supply Costs” Anaesthesia and Analgesia (2006) 102:524-529.
5. Francesco Indelli P, Grant SA, Nielsen K, Parker Vail T “Regional Anaesthesia in Hip Surgery” Clinical Orthopaedics and
Related Research (2005) 441:250-255.
6. Cousins M, Bridenbaugh P “Neural blockade in clinical anaesthesia and management of pain” 2nd edition (1988).
Philadelphia: J B Lippincott.
7. Eroglu A, Uzunlar H, Erciyes N “Comparison of hypotensive epidural anaesthesia and hypotensive total intravenoue
anesthesia on intraoperative blood loss during total hip replacement” Journal of Clinical Anesthesia (2005) 17:420-425.
8. European Society of Regional Anaesthesia and Pain Therapy “Procedure Specific Postoperative Pain Management”, Accessed
at: http://www.postoppain.org/frameset.htm on 15th December 2007.
9. Rashiq S, Finegan BA “The effect of spinal anesthesia on blood transfusion rate in total joint arthroplasty” Canadian Journal
of Surgery (2006) 49(6):391-396.
10. Sharrock NE, Fischer G, Goss S, et al “The early recovery of cognitive function after total hip replacement under hypotensive
epidural anaesthesia” Reg Anesth Pain Med (2005) 30:123-127.
11. Auroy Y, Narchi P, Messiah A, et al “Serious complications related to regional anaesthesia” Anesthesiology (1997) 87:479-
486.
12. Robinson N, Hall G “How to Survive in Anaesthesia” 2nd
edition (2002) BMJ Books.
13. http://home.satx.rr.com/altitudedcs/radical.htm
14. http://www.cartoonstock.com/lowres/jwe0318l.jpg
15. Bromhead H “Anaesthesia for Total Hip Replacement” Accessed at:
http://www.anaesthesiauk.com/article.aspx?articleid=100977 on 8th
January 2008.
Editor's Notes
GAGaseous or intravenous drugs achieve central neurological depression
RADrugs are administered directly to the spinal cord or nerves to locally block afferent and efferent nerve input
IV sedation frequently used with RA to help patient tolerate surgery. N.B. Sedated patient should be able to talk to you at all times, DO NOT CONFUSE WITH GA
Epidural = into space above the dura. Tends to be continuous and leave catheter in.
Spinal = into subarachnoid space. Usually single shot. Can put catheter in but tends to be removed at end of op, due to risks of giving massive spinal accidentally and infection etc. Faster onset than epidural and lower failure rate.
Combined spinal epidural – get the rapid onset dense block of a spinal, plus the ability to extend the block/analgesia with the epidural
Lumbar and sacral plexus block is not very popular due to lack of experience at the technique.
Commonest RA technique used in the UK for THR is spinal
Combination of GA/RA tends to be GA plus epidural, or GA plus lumbar plexus block
Lower prevalence of DVT - OR 0.27 (95% CI 0.17-0.42) 2
Lower prevalence of PE - OR 0.26 (95% CI 0.12-0.56) 2
Lower requirement for blood transfusion - OR 0.73 (95% CI 0.56-0.95) 9
Decreased DVT as increased peripheral blood flow. Arterial inflow, venous emptying rate and venous capacity all significantly higher in patients receiving RA rather than GA – against thrombus formation.
However the authors of the meta-analysis do say that most of the studies included were performed before the use of DVT prophylaxis (LMW heparin) became standard, so limits the applicability of these results to present day practice.
However is there potentially a summative effect of LMW heparin and RA as they affect different parts of Virkow’s triad
Patients in GA group were admitted to PACU with a higher pain score and needed more analgesics (i.e. higher opioid consumption) than patients in the spinal group.
Better immediate post-op analgesia linked with increased patient satisfaction (McNeill et al, 1998)
Post-op pain management – factors that shorten length of stay and allow quicker rehabilitation. Consequences of severe postop pain are prolonged hospital stay, increase hospital readmission, precipitation in the use of opioids with subsequent increase in postoperative nausea and vomiting, and overall low patient satisfaction.
Peri-operative mortality. Discuss background to this BMJ meta-analysis. Over what time scale was it. Would need a large number of patients to show a difference in mortality as there is not a lot of mortality associated with THR and orthopaedics. A paper looking at mortality associated with abdominal surgery (which is higher risk than THR) showed there was no difference in peri-operative mortality between RA and GA, so likely that this BMJ article is not true.
Costs of anaesthesia supplies, drugs and gases used in each case were recorded during the entire procedure from start of anaesthesia to discharge from post-anesthesia care unit (PACU). This study did not include the cost of personnel, and unless has large impact like needing less recovery nurses for example, then unlikely to make a huge amount of impact on cost.
Peri-operative mortality reduced 3
58/1768 (3.3%) events per RA patients compared with 89/1849 (4.8%) GA patients
3 Epidural or Spinal vs GA
Potentially delayed start to surgery due to placement of block
Failure of block with subsequent conversion to GA
More likely to get urinary retention and require a urinary catheter
Central neuraxial block (i.e. spinal and epidural) – great care needed in patients with aortic stenosis. As potential for CVS instability if block too high and takes out sympathetic chain at T1-T5.
Absolute contraindications to RA = patient refusal and local sepsis
Faster induction meaning can get them off to sleep quicker.
Control of airway in case anything goes wrong (though could argue that a patient being awake and able to control their own airway is even better)
Volatile anaesthetics cause post-op nausea
Co-morbidities:
DM – less stress response with RA, so glucose control post-op better
Respiratory illness – RA provides better non-opiate analgesia, so less respiratory depression
Anaesthetic history
Malignant hyperthermia
Drugs
Antiplatelets and anticoagulants – spinal haematoma is a complication of a central neuraxial block such as spinal/epidural. Can cause paralysis. More likely to bleed if on antiplatelet/anticoagulant
Allergies
Anaphylaxis to certain anaesthetic drugs
Airway
Difficult airway – best protection against this is to keep patient awake!
Patient preference
Scared about being awake
Case review of orthopaedic procedures showed 48% of surgeons directed their patient’s choice of anaesthetic (Oldman et al, 2004)
Absolute and relative contraindications to epidural:
Absolute – patient refusal, abnormal clotting, infection (local on back, septicaemia), allergy to LA
Relative – raised ICP, hypovolaemia, chronic spinal disorders, CNS disease, drugs (e.g. aspirin, NSAIDs, low dose heparin)
Complications of epidural:
Severe hypotension, accidental IV injection, dural puncture so effectively giving a massive spinal anaesthetic and get a headache
Patient co-morbidities
Patient weight
Patient shape of back
Patient’s preference
Can patient tolerate being awake?
Patient medication
Skills of the anaesthetist
Length of surgery
Previous anaesthetic history
Limited neck mobility
Facilities and funds available
