anaesthesia for replacement surgeries nitasha

8/3/2019 Anaesthesia for Replacement Surgeries Nitasha

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Anaesthesia for jointreplacement surgeries

Consultant:

Dr. Kajal jain

Presenters:

Dr. Sujith

Dr. Nitasha

Dr. Poorna


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Introperative anaesthetic concerns Patient position

Blood loss

Cement reactions

Thromboembolism

Use of tourniquet

Hypothermia


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Blood loss in joint replacement surgeries

High risk:

Total arthroplasties

Revision surgeries

Inexperienced surgeon

Bilateral knee arthroplasties Cementless hip replacements


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Blood loss can be minimised by:

Preop intraop postop

Bleeding history anaesthetic: regional anaes reduced phlebotomy

CBC, coagulation euthermia careful anticoagulat

Eliminate antiplatelet pharmacological: fibrin nutrition

Anticagualants bone wax, Adr sponges, thrombin

PAD systemic antifibrinolytics, wound

compression


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Options for blood management

Allogenic blood transfusion

Preoperative autologous blood donation

Salvage procedures

Acute normovolaemic hemodilution

Increase hemetopoeisis: iron/ erythropoeitin


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DVT AND PULMONARY EMBOLISM

Without prophylaxis 40-60% have DVT after THR , 60- 80% after TKR*

Rarely fatal PE

Pathophysiology( Virchows triad):

stagnant blood flow through veins

damage to vein walls

coagulation encouraged by the debris

Intraooperatively: 1. Activation of the clotting cascade occurs during

instrumentation of the medullary canal/ distal part of femur

2.Stasis in femoral venous flow: extremes of position

use of tourniquet

3.Endothelial injuiny during kinking of the femoral vein

Ref:Chest 2004;126;338S-400S


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Guideline recommendations


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Preoperative care:

1. All patients should be assessed preoperatively for elevated risk of PE( LOE III

B)

- hypercoagulable states

- H/O PE

2. All patients to be evaluated preoperatively for elevated risk of major bleeding(

III C) -h/o recent stroke

- recent gastrointestinal bleed

- bleeding diasthesis

Intraoperative care: 1. Patients should be considered for intra-operative and/or

immediate postoperative mechanical prophylaxis( LOE III B)

2. In consultation with the anesthesiologist, patients should be considered for

regional anaesthesia( LOE IIIC)


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Postoperative care:1 Post-operatively, patients should be

considered for continued mechanical prophylaxis until discharge to

home.( LOE IV C)

2. Post-operatively, patients should be mobilized as soon asfeasible to the full extent of medical safety and comfort( LOE VC)


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Chemopropylaxis:

1. Patients at standard risk of both PE and major bleeding should be

considered for one of the chemoprophylactic agents

a.Aspirin, 325 mg 2x/day (reduce to 81 mg 1x/day if gastrointestinal symptoms

develop), starting the day of surgery, for 6 weeks.

b. LMWH, dose per package insert, starting 12-24 hours post-operatively (or

after an indwelling epidural catheter has been removed), for 7-12 days .

c. Synthetic pentasaccharides, dose per package insert, starting 12-24 hours

postoperatively(or after an indwelling epidural catheter has been removed)


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Patients at elevated (above standard) risk of PE and at standard risk of major

bleeding should be considered for one of the following:

a. LMWH, dose per package insert, starting 12-24 hours post-operatively (or after an

indwelling epidural catheter has been removed), for 7-12 days

b. Synthetic pentasaccharides, dose per package insert, starting 12-24 hours

postoperativel(or after an indwelling epidural catheter has been removed), for 7-12

days

c. Warfarin, with an INR goal of 2.0, starting either the night before or the night after

surgery, for 2-6 weeks

Routine screening for DVT or PE post-operatively in asymptomatic patients is

not recommended


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Bone cement implantation syndrome

characterized by hypoxia, hypotension or both and/or unexpected loss of

consciousness occurringaround the time of cementation, prosthesis

insertion, reduction of the joint or, occasionally, limb tourniquet

deflation

Proposed severity classification

Grade 1: moderate hypoxia (SpO2,94%) or hypotension[fall in systolic

blood pressure (SBP) .20%].

Grade 2: severe hypoxia (SpO2,88%) or hypotension(fall in SBP .40%) orunexpected loss of consciousness.

Grade 3: cardiovascular collapse requiring CPR


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Risk factors

old age

poor preexisting physical reserve

impaired cardiopulmonary function,

pre-existing pulmonary hypertension

osteoporosis

bony metastases

concomitant hip fractures ,particularly pathological or inter

trochanteric fractures


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Aetiology and pathophysiology

Monomer mediated model: MMA monomer induced vasodilation

Emboli model: high intramedullary pressures

exothermic reaction

trapping air and medullary contents

temperature can increase as high as 96C 6 min after mixing the

components.

Hemodynamic effects: can embolise to lungs, heart and even coronary

and cerebral circulation in cases of paradoxical emboilsm


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Anaesthetic risk reduction

Proper preoperative assesment / evaluation /optimisation of co

morbidities

Discussion with surgeon regarding use of cemented prostheses

The anaesthetic technique and the type of prosthesis

avoidance of nitrous oxide

Increasing the concentation of inspired oxygen during cementation

Avoid intravascular volume depletion

invasive monitoring /CO monitoring


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Surgical risk reduction

Medullary lavage

Good hemostasis before cement insertion

Minimising the length of prosthesis

Use of non cemented prosthesis, venting the medullaion

Use of guns and retrograde insertion technique for cement insertion causes

even distribution of medullary pressure


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Management

Good communication b/w surgeon and anaesthetists

Clinical alerts: a fall in etCO2

Oesophageal doppler

Increase Fio2 to 100%

Inotropic support


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Hypothermia

Haemostatic mechanisms are reduced with old age;

anaesthesia-induced peripheral vasodilatation,

large wound surface area,

high-flow laminar theatre circulation systems,

major fluid shifts or

prolonged surgery.

Warmed fluids and use of hot air warmers desirable


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Use of tourniquet

Dr. Harvey Cushing ( 1904)

Provide bloodless surgical field but not without risks and complications

Application of tourniquet: The diameter of the cuff used should be wider than

half the diameter of the limb. It should be applied furthest away from the

surgical site and preferably over an area with the most fat and muscle padding.

Inflation pressures for lower limbs: at least 100 mm Hg above systolic

arterial blood pressure (usually 300500 mm Hg).

Inflation pressures for upper limbs: at least 50 mm Hg above systolic

arterial blood pressure (usually 250300 mm Hg


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Recommendations for time limit

varies from 30 minutes to 4 hours,

should be deflated after 2 hours for 1520 minutes

tourniquet should be used for only a further 60 minutes.


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Effects of tourniquet

During inflation

Cardiovascular effect:

circulating blood volume (up to 15%) and SVR (up to 20%).

bilateral simultaneous inflation - rise in CVP may cause volume overload

or even cardiac arrest.

Tourniquet pain A sudden heart rate and systolic and diastolic blood

pressures may occur after 3060 minutes

Haematological effects: 1. Systemic hypercoagulability. 2. deep vein

thrombosis

Metabolic effects: After 30 minutes, anaerobic metabolism occurs


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After deflation

Cardiovascular effect:1.During limb reperfusion, a transient decrease in

systemic vascular resistance accompanied by a compensatory increase in cardiac

index may occur. This avoids a severe decrease in mean arterial pressure.

2. Reactive hyper-reperfusion and vasospasm

Metabolic effects:

Increase in lactate and PaCO2

Decrease in pH.

Increase in plasma K+ level


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Post operative pain management

Analgesia: 1. Neuraxial techniques

2. Nerve blocks( single shot/ continous)

3. NSAIDS

4 systemic opoids( PCA regimen)

5. PCEA regimen


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Systemic opioids

Morphine : oral: 10-30 mg qid

:injection: 2- 15 mg sc/im/iv

Fentanyl : injection 50- 100 g/dose

transdermal: 25 g/hr q 72 hrs

tramadol : oral: 50- 100 mg qid

injection: 0.25 mg/kg iv


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PCA REGIMENS


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Dosing of neuraxial opioids

drugIntrathecal

dose

Epidural single

dose

Epidural

continous

infusion

fentanyl 5-25 g 50-100 g 25-100 g/hr

morphine 0.1- 0.3 mg 1-5 mg 0.1- 1 mg/hr

sufentanyl 2- 10 g 10- 50 g 10-20 g/hr


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Epidural dosing of local anaesthetics for postop

analgesia

Bupivacaine: 0.125-0.166% 5- 10 ml intermittent boluses or

continous infusion @ 5-12 ml/hr

Ropivacaine: 0.2% with infusion @4-6 ml/hr for 48 hrs


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Adjuvants

Clonidine:- Epidural: 75-150 g single dose in a 10 ml solution

containing 2mg of morphine and 0.125% bupivacaine

Intrathecal: 300-400 g

Dexmedetomidine: both sedation and analgesia

morphine sparing effect

0.2-0.7 g/kg/hr iv infusion

1g/kg in epidural analgesic mixture

- did not reduce the onset time, but produces a dense sensory and motor

block


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PCEA

Lower doses, greater patient satisfaction, lower incidence of S/E

Analgesic

solution

Continous rate

( ml/hr)

Demand dose

(ml)

Lockout

interval

(mins)

0.05%bupivac

aine+4/ml

fentanyl

4 2 10

0.0625%bupiv

acaine+ 5/mlfentanyl

4-6 3-4 10-15

0.1%bupivaca

ine+5/ml

fentanyl

6 2 10-15


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Analgesic

solution

Continous

rate

Demand

dose(ml)

Lockout

interval

( min)

0.2%

ropivacain

e+5g/ml

fentanyl

5 2 20

0.125%

bupivacain

e+ 0.5/ml

sufentanyl

3-5 2-3 12


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Hip and knee arthroplasty


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Anaesthesia for hip and knee replacement

Preoperative preparation

optimisation of co-morbidities

cross-matched blood .

deep vein thrombosis (DVT) prophylaxis

ensure appropriate timing of low-molecular-weight heparin.

Antibiotic prophylaxis (usually cephalosporin or aminoglycoside)

Invasive monitoring significant cardiac disease or large blood loss .

Large bore intravenous access (sited in the non-dependent arm for

laterally positioned patients).


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Anaesthetic technique

Regional anaesthesia is the technique of choice:

Reduces blood loss

improve cement bonding,

reduces surgical time

avoidance of airway compromise and cervical movement during

instrumentation

Decreases the incidence of DVT and pulmonary embolism

Improved postoperative analgesia

Enhanced early postoperative rehabilitation / improved outcome (especially

shoulder and knee arthroplasty)


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Reduction in the effects of general anaesthesia and systemic opioid

analgesia on pulmonary function

reduced incidence of PONV

It may avoid the need for endotracheal intubation and the consequent

vasopressor response


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Regional anaesthetic techniques

Lower limb surgery:

Central neuraxial blockade: 1. spinal

2. epidural

3. CSE

Peripheral nerve blocks:

- provide long lasting analgesia

- improved mobility

Disadvantage: may be more difficult to perform


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Peripheral nerve blocks for hip replacement

Lumbar paravertebral

Lumbar plexus block

Sciatic nerve block + lumbar plexus block

PERIPHERAL NERVE BLOCKS FOR KNEE


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PERIPHERAL NERVE BLOCKS FOR KNEE

REPLACEMENT

total knee arthroplasty severe pain :extensive osteotomy and quadriceps

splitting

Continuous peripheral nerve blocks provide the most effective and long-

lasting analgesia with fewer side effects when compared with PCA

morphine or continuous epidural analgesia

Blocks for TKR: 1. femoral nerve block

2. sciatic nerve block

3. obturator nerve block

4. lumbar plexus block


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Lumbar plexus anatomy


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Lumbar plexus block

Indications:

Hip, anterior thigh and knee surgery

Landmarks: iliac crest

spinous process

Needle insertion 4-cm lateral to the intersectionof landmarks 1 and 2


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Position:The patient is in the

lateral decubitus position with

a slight forward tilt

Needle insertion

:The needle is inserted at a

perpendicular angle to the

skin. The nerve stimulator

should be initially set to

deliver 1.5 mA current.


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Sciatic nerve block

- posterior( Labats approach)- classical technique

- anterior

- lateral

require adequate set-up

resists local anesthetic penetration,leading to longer block onset times

saphenous nerve block, either directly or via femoral nerve block ;complete anesthesia of the leg below the knee


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Landmarks for sciatic

nerve block

1Draw a line between the greater

trochanter to the posterior superior

iliac spine (PSIS).

2.Draw a second line from the

greater trochanter to the patientssacral hiatus (Winnies

modification).

3.Determine the point of initial

needle insertion by drawing a line

perpendicular from the midpoint of

the first line to its intersection with

the second


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Needles:

21-gauge, 10-cm insulated needle for themajority of patients. For

obese patients, 15-cm needles may be needed

18-gauge, 10-cm insulated Tuohy needle for catheter placement.

Insert catheters 5 cm beyond the needle tip.

Successful needle placement in proximity to the sciatic nerve is

observed with plantar flexion/inversion (tibial nerve) or

dorsiflexion/eversion (common peroneal nerve) with 0.5 mA or

less of current.

Local Anesthetic: In most adults, 20 to 30 mL of local anesthetic

is sufficient to block the plexus


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Studies of this posterior approach have demonstrated that plantar

flexion of the foot (tibial nerve stimulation) resulted in a shorter onset

time and more frequent success of the block versus dorsiflexion

(common peroneal nerve)

The posterior approach with the lumbar plexus block provides complete

anaesthesia of the lower extremity


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Anterior approach to sciatic nerve block

A 22 gauge 12- 15

cm needle is inserted

at the point of

intersection between

two lines

At this point it meets

lesser trochanter.

Paresthesias elicited

at a depth of 5 cm


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Alternative techniques to sciatic nerve block

Posterior approach in

supine Parasacral technique


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Femoral nerve block( 3 in -1 block)

Indications: anterior thigh and knee surgery

Landmarks: 1. femoral crease

2. femoral pulse

Euipments: 22G 5 cm needle

18G Tuohy needle for catheter placement

Local anaesthetic: 20-40 ml


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Pearls

Commonly the anterior branch of femoral nerve encountered first(

contraction of sartorius)

Needle redirected slightly laterally and with a deeper direction (

contraction of quadriceps)


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Shoulder arthroplasty


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Monitoring and intravenous access

Standard full patient monitoring attached

A large intravenous access taken


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Regional technique for shoulder arthroplasty

Interscalene block

Continous interscalene block( anterior and posterior

approaches)

Suprascapular block: mainly acts as a supplement to

general anaesthesia for postoperative pain

I l bl k S fi i l l d k


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Interscalene block Superficial landmarks

Position: place the patient supine

with head turned towards opposite

side

Technique: palpate C6 ( CRICOID).

Palpate SCM posterior border and

feel the interscalene groove at C6

level. EJV crosses at this point.

Insert needle posterior to it.

Needle: 22G 5 cm needle

Local anaesthetic solution: 30-40

ml

Goal : contraction of deltoid or

pectoralis major


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USG guide interscalene blocks

Probe: high frequency ( 5-12 Hz),

linear

Position: The oblique plane gives the

best transverse view of the brachial

plexus; Position the probe on the neck

at the level of C6

Approach. To use the

posterior approach, begin the needle

insertion at the lateral aspect of the

probe; . For the anterior approach,

insert the needle at the medial aspect

of the probe, taking care to avoid the

carotid artery and internal jugular vein


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Continous catheter techniques


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Drug delivery

Initial bolus:0.25ml/kg ropivacaine (0.5%) or bupivacaine

(0.5%) as a bolus injection for intra- and postoperative

analgesia if the block is combined with general anesthesia [3].

Solely given 0.5 ml/kg

Continous infusion: 5ml/hr of 0.25% ropivacaine or 0.25%

bupivacaine


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Suprascapular nerve block

The suprascapular nerve ( C5-C6) arises from the superior trunk of the

brachial plexus and supplies the posterior part of the shoulder joint

Acts as a supplement to general anaesthesia and reduces opioid

requirements

Technique: insert the needle 1cm above scapular spine parallel to the

vertebral spine until it contacts the vertebral spine near the suprascapular

notch. 10 ml of local anaesthetic solution is given as field block


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Postoperative analgesia

1. systemic opiates

2. intraarticular administration of opiates

3. regional analgesia: epidural catheter

interscalene catheter

suprascapular catheter


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Elbow arthroplasty


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Regional techniques for elbow replacement

BRACHIAL PLEXUS BLOCK

Anatomy : performed at the level of divisions where the plexus passes

between the clavicle and the subclavian artery

Indications: surgeries below the mid humerus

advantage: SPINAL OF THE ARM

Equipments: 1. USG machine- 8-12 Mhz

2. needles

3.local anaesthetic


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Landmarks for USG guided approach

The USG probe positioned in

the supraclavicular fossa,

pointing caudad, and moved

lateral

Once the subclavian artery is

visualized, the area lateral and

superficial to it is explored

until the plexus is seen, with a

characteristic honeycomb

appearance laterally and

medially


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Right supraclavicular plexus


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Infraclavicular block

The infraclavicular block is performed at the level of the cords of the

brachial plexus.

Indications: Elbow, forearm, hand surgery

It also provides excellent analgesia for an arm tourniquet.


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Superficial landmarks


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USG guided landmarks

Probe Position. The

parasagittal plane gives

thebest transverse view of

the brachial plexus

The needle is typically

inserted in-plane at the

cephalad (lateral) aspect of

the probe, and will bevisualized at the lateral

border of the axillary artery


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Hemophilia

Hemophilia is an X- linked recessive disorder

Occurs only in males, females act as carriers

Characterised by deficient factor VIII , IX

Classified in severity by the factor VIII levels

Normally 1U/ml= 100% of factor

Severe < 1%, moderate 1-4% , mild 4- 50%


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Anaesthetic concerns

High risk of hepatitis C,HIV

The need to avoid i.m injections

Problems of venous access


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Joint replacement surgery in hemophiliacs

indications contraindications

It is usually not recommended

until endstage, bone-on-bone

joint disease is present

degenerative disease that is

painful and may have

associated stiffness and

deformity, which is causing

functional impairmentt

presence of an active infection

AIDS and liver disease

A history of non-compliance

with recommended hemophilia

care may be a warning of an

unsuccessful outcome


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Preoperative assessment

To maximise the possibility of good outcome the patient should be seen

a minimum of six weeks before the scheduled procedure

Preoperative screening tests:

Inhibitor status

HIV antibody, viral load, and CD4 count

Hepatitis C and viral load

Fibrinogen, prothrombin time/INR, platelet count

Cardiopulmonary status

Inspection of venous access


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Choice of factor: Hemophilia A:

plasma derived or recombinant factor

Cryoprecipitate

Hemophilia B:

Purified factor IX containing product

APTT should be monitored after factor replacement


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Other blood support product

Intraoperative cell salvage procedures

Oral / iv iron replacement

Fibrinogen should be maintained above 150 mg/dl, INR< 1.5,and

platelets >50,000 for the first couple of days.

Vitamin K can be given to improve hepatic synthesis

Postoperative considerations


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Postoperative considerations

Pain Management:

Regional anesthesia with epidural catheters can be quite useful in the

first 24-48 hours after surgery. There is, however, a risk of spinal

/epidural hematoma

PCA Regimens

Surgical considerations: The drains are removed at 24 hours following

surgery,and the first dressing is changed at 48 hours


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thankyou


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anaesthesia for replacement surgeries nitasha

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