ORTHO ANAESTHESIA

1. Anesthesia for Orthopedic
Surgery
Key concepts
Presenter : Dr Vivek Sharma
Resource : Ch. 38 , Morgan
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No. of slides : 23

2. Bone Cement Implantation
Syndrome (BCIS)
• Potentially fatal complication of orthopaedic sx,
involving bone cement.
• Hypoxia , hypotension ,loss of consciousness
• Incidence- 20%, CVS collapse in 0.5-1.7%
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3. Bone cement
• Acrylic substance
• secure implants to bone / joints
• a filler /not adhesive.
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5. Bone cement implantation syndrome
• Hypoxia
• Hypotension
• Arrhythmias (Heart Block And Sinus Arrest)
• Pulmonary Hypertension (Increased PVR)
• Decreased Cardiac Output
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8. Bone cement implantation syndrome
• Undergoes an exothermic reaction and expands between the space of the
bone and prosthesis trapping air and medullary contents under pressure.
• The temperature of cement can increase up to 96 c. When prosthesis is
put, the contents escape into the interstices of bone because of already
developed intramedullary hypertension.
• Hardening / expansion , results in intramedullary htn (>500 mm hg) &
embolization of fat, bone marrow, cement, air into venous channels.
• This leads to embolization. Knowing that the extent of embolization is
proportional to the intramedullary pressure.
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9. • Systemic absorption can produce vasodilation and a decrease
in SVR
• The debris from the medulla can embolize to the lungs and
heart. It is the shower of pulmonary emboli that result in
characteristic circulatory changes leading to hypoxia and right
ventricular dysfunction, though the degree of cardiovascular
collapse is not proportional to the degree of embolization.
• Release of tissue thromboplastin may trigger platelet
aggregation, microthrombus formation in the lungs
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10. Risk factors
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12. Why room temp kept cold during
cement application ?
• Bone cements are heat sensitive. Any increase or decrease in temperature (either ambient,
and/or of the cement components and mixing equipment) from the recommended
temperature of 73 F (23 C) affects the handling characteristics and setting time of the
cement.
• Manual handling and body temperature reduces the final setting time. Variations in humidity
affect the cement handling characteristics and setting time.
• Exposure to light or high temperatures can cause premature polymerization of the liquid
component.
• It is recommended that the unopened cement components are stored at 73 F (23 C) for a
minimum of 24 h before use.
• Vacuum mixing of cement can also accelerate the setting time of the cement.
• High viscosity cements are sometimes pre-chilled for use with mixing systems for easier
mixing and prolonged working phase. This will also increase the setting time.
• The relative humidity might also influence the handling properties. That is the reason why
the working time and setting time of the cement might vary in winter and summer.
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13. PNEUMATIC TOURNIQUET
• Use on an extremity creates a bloodless field
that greatly facilitates the surgery.
• potential problems including hemodynamic
changes, pain, metabolic alterations, arterial
thromboembolism, and pulmonary embolism
.
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14. tourniquet pressure
• patients <16 years should have a tourniquet
pressure of limb occlusion pressure plus 50
mmHg or systolic blood pressure plus 50-100
mmHg.
• Patients >16 years should have a tourniquet
pressure of systolic blood pressure plus 70-
130 mmHg for the lower limb and 50 -100 mm
Hg for the upper limb.
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15. pneumatic tourniquet
• Inflation pressure is usually set approximately
100 mm Hg higher than the patient’s baseline
systolic blood pressure.
• Prolonged infl ation (>2 h) routinely leads to
transient muscle dysfunction from ischemia
• may produce rhabdomyolysis or permanent
peripheral nerve damage.
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16. tourniquet time
• The ischaemic tourniquet time should ideally be
less than 120 minutes and only extended beyond
this after a clinical assessment of the relative risks
and benefits, by the operating surgeon.
• Audible reminders must be given to the operating
surgeon every 10 minutes beyond 120 minutes,
and tourniquet use beyond 150 minutes is rarely
justified.
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17. Tourniquet places
• Traditionally the tourniquet is applied to
the most proximal part of the operated limb,
where the muscle bulk is greatest, protecting
peripherally exposed nerves (i.e the above-
elbow or above-knee sites).
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18. cuffs
• wider cuffs (14 cm) were less painful than
narrow cuffs (7 cm) if inflated at lower
pressures
• should not directly overlie bony prominences
like the head of fibula or malleoli as there is
risk of direct nerve compression.
• edge of the tourniquet should be at least 2 cm
distal to the head of fibula and 2 cm proximal
to the malleoli in case of calf cuffs.
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19. cuffs
• applied very carefully to the proximal part of the limb at the greatest
circumference because the muscle bulk at that site is the greatest, and
hence it affords a greater protection against nerve injury.
• The tourniquet should be inflated after the limb has been exsanguinated
and prepared for surgery.
• A safe time limit of 1–3 h has been described. Use of tourniquet for >2 h
and pressures of >350 mm Hg in lower extremity and >250 mm Hg in
upper extremity increases the risk of compression neurapraxia. If >2 h is
required, the tourniquet should be deflated for 5 min for every 30 min of
inflation time.
• Orthopedic surgeons generally practice fixed inflation pressures (typically
250 mm Hg for upper arm and 300 mm Hg for thigh) or fixed amount of
pressure above systolic arterial pressure (typically +100 mm Hg for upper
arm and 100–150 mm Hg for thigh).
• These practices should not be followed as these do not take into account
the age in both and the blood pressure (BP) of the patient in the former
technique.
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20. contraindications
• Limbs with severe infection, patients with
poor cardiac reserve, and traumatized limbs
are relative contraindications to tourniquet
use.
• Peripheral neuropathy, DVT in the limb,
Reynaud's disease, and peripheral vascular
disease should be ruled out before
considering tourniquet application.
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21. Bruner's ten rules for the safe use of tourniquet (Modified by
Barithwaite and Klenerman)
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22. • Histological evidence of muscle damage is evident 30–60 min after
tourniquet inflation.
• Decreased pH (<6.5),decreased pO2,increased pCO2, increased K+,
increased lactate, occur progressively.
• These changes are generally mild and well tolerated.
• Tourniquet pain develops in up to 66% of patients, 30–60 min after
cuff inflation.
• Tissue edema develops if the tourniquet time exceeds 60 min.
• After deflation, the return of circulation leads to the development
of the reperfusion injury.
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23. Bier block
• The technique of intravenous regional anesthesia (IVRA), or “Bier block,” was first introduced
in 1908 by the German surgeon August Bier.
• Injecting local anesthetic solutions into the venous system of an upper or lower extremity
that has been exsanguinated by compression or gravity and that has been isolated by means
of a tourniquet from the central circulation.
• In Bier’s original technique, the local anesthetic procaine of 0.25% to 0.5% was injected
through an IV cannula, placed between two Esmarch bandages utilized as tourniquets to
divide the arm into proximal and distal components.
• After injecting the local anesthetic, Bier noted two distinct types of anesthesia: an almost-
immediate onset of “direct” anesthesia between the two tourniquets and then, after a delay
of 5 to 7 minutes, an “indirect” anesthesia distal to the distally placed tourniquet.
• direct anesthesia was the result of local anesthesia bathing bare nerve endings in the tissues,
whereas the indirect anesthesia was most probably due to local anesthesia being transported
to the substance of the nerves via the vasa nervorum, where a typical conduction block
occurs.
• Bier’s conclusion was that two mechanisms of anesthesia were associated with this
technique: peripheral infiltration block and conduction block.
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24. Bier block
• Upper Extremity
• Intravenous regional anesthesia using local anesthetic, most
commonly lidocaine 0.5%–1% (prilocaine 1% in Europe), is
appropriate for surgery and manipulation of the extremities
requiring anesthesia of up to 1 hour’s duration.
• It is most suited for peripheral, soft tissue operations such as
ganglionectomy, carpal tunnel release, Dupuytren’s contracture
surgery, or reduction of fractures.
• However, the necessity of exsanguinating the extremity using an
Esmarch bandage, a potentially painful maneuver, may preclude
certain procedures from being undertaken with this technique
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25. Bier block
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26. Bier block
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27. Bier block
• • An intact tourniquet system is essential for the successful and safe
performance of IVRA.
• Unintentional deflation of the tourniquet or the presence of a
vascular communication even with an intact, functioning tourniquet
may result in severe systemic toxicity.
• When the surgical procedures is shorter than 30 minutes,
intermittent cuff deflation and inflation may effectively prolong the
time to achieve peak arterial concentrations of the local anesthetic
but may not be entirely reliable in minimizing toxicity due to release
of local anesthetic into the circulation.
• The tourniquet should not be deflated until at least 30 minutes
has elapsed from the time local anesthetic (and adjuvants, if used)
is injected into the isolated venous system.
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28. Bier block
• Tourniquet deflation after IVRA is associated with signs and
symptoms of systemic local anesthetic toxicity, ranging from mild
events related to the central nervous system, such as tinnitus and
perioral numbness, to seizures, and finally to devastating
cardiovascular collapse.
• These correlate with local anesthetic concentrations in arterial
blood and not to venous concentrations.
• tourniquet pain, which not uncommonly occurs if a double
pneumatic device is not utilized
• Very rare, isolated reports of neurologic complications, including
damage to the median, ulnar, and musculocutaneous nerves, are
associated with IVRA.
• Compartment syndrome may occur rarely
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29. Fat embolism syndrome
• classically presents within 72 h following long-
bone or pelvic fracture, with the triad of
dyspnea, confusion, and petechiae .
• fat globules are released by the disruption of
fat cells in the fractured bone and enter the
circulation through tears in medullary vessels.
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35. Schönfeld’s Criteria:
-Diagnosis requires a score of more
than 5.
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36. Management:
A) Supportive
1-Ensuring good arterial oxygenation: High flow rate of oxygen is given to maintain the arterial oxygen tension in the normal
range.
2-Restriction of fluid intake and Diuretics: to minimize fluid accumulation in the lungs so long as circulation is maintained.
3-Maintenance of intravascular volume: is important because shock can exacerbate the lung injury caused by FES. Albumin has
been recommended for volume resuscitation in addition to the balanced electrolyte solution, because it not only restores blood
volume but also binds fatty acids, and may decrease the extent of lung injury.
4-Mechanical ventilation (APRV) and Positive End-Expiratory Pressure (PEEP): may be required to maintain arterial oxygenation.
B) Pharmacological
1-Corticosteroids: Methylprednisolone (membrane stabilizer, decreases endothelial damage caused by free fatty acids).
Methylprednisolone 1.5 mg kg−1 i.v. can be administered every 8 h for six doses
2-Low dose heparin: 2500 u / 6 h. (reduce the degree of pulmonary comprise and intravascular coagulation despite the risk of
hemorrhage and intravascular lipolysis).
3-Dextran-40: (decreases intravascular thrombosis when ESR is elevated).
4-Ethanol: (decreases lipolysis)
5-Dextrose: (decreases free fatty acid mobilization)
6-DVT prophylaxis
7-Nutrition
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37. Management:
C) Surgical:
1-Prompt surgical stabilization of long bone fractures within 24 h. reduces the risk of the syndrome.
2-Use of vacuum or venting during reaming of long bones.
3-Prophylactic IVC filter in at-risk patients.
Prognosis:
➧ The mortality rate from FES is 5-15%. Even severe respiratory failure associated with fat embolism
seldom leads to death.
➧ The prognosis is worse in older patients and those with more severe injury but is not affected by
gender.
➧ Criteria of bad prognosis: Serum lipase, Lipuria, ARDS.
Prevention:
➧ Early immobilization of fractures seems to be the most effective way of reducing the incidence of this
condition.
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39. Deep vein thrombosis and pulmonary
embolism
• can cause morbidity and mortality following
orthopedic operations on the pelvis and lower
extremities .
• Risk factors include obesity,age > 60 years, procedures
lasting > 30 min, use of a tourniquet, lower extremity
fracture, and immobilization for > 4 days.
• Patients at greatest risk include those undergoing hip
surgery and knee replacement or major operations for
lower extremity trauma.
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40. Thromboembolic complications
• sympathectomy induced increases in lower extremity venous
blood flow
• systemic anti-inflammatory effects of local anesthetics,
• decreased platelet reactivity
• Underlying pathophysiological mechanisms include
venous stasis with hypercoagulable state due to
localized and systemic infl ammatory responses to
surgery..
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46. Managment
• and the routine use of
mechanical devices such
as intermittent pneumatic
ompression (IPC) have
been shown to decrease
the incidence of DVT and
PE.
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For patients at increased risk for DVT but
having “normal” bleeding risk, low-dose
subcutaneous unfractionated heparin (LUFH),
warfarin, or low-molecular-weight heparin
(LMWH) may be employed in addition to
mechanical prophylaxis.

47. • For patients at increased risk for DVT but
having “normal” bleeding risk, low-dose
subcutaneous unfractionated heparin (LUFH),
warfarin, or low-molecular-weight heparin
(LMWH) may be employed in addition to
mechanical prophylaxis.
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48. patients receiving prophylactic lowmolecular-
weight heparin once daily
• Neuraxial techniques may be performed (10–
12 h after the previous dose, with a 4-h delay
before administering the next dose .
• Patients on warfarin therapy should not
receive a neuraxial block unless the
international normalized ratio (INR) is normal
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52. patients with rheumatoid arthritis
• Flexion & extension lateral radiographs of cervical
spine should be obtained preoperatively in pts with
RA severe enough to require steroids, immune
therapy, or methotrexate.
• If atlantoaxial instability is present, intubation
should be performed with inline stabilization utilizing
video or fiberoptic laryngoscopy .
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53. Bilateral Hip Arthroplasty
• Effective communication between the
anesthesiologist and surgeon is essential during
bilateral hip arthroplasty.
• If major hemodynamic instability occurs during the
first hip replacement procedure, the second
arthroplasty should be postponed .
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54. knee arthroscopy/ knee replacement
• Adjuvants such as opioids, clonidine, ketorolac,
and neostigmine when added to local anesthetic
solutions for intraarticular injection have been
used in various combinations to extend the
duration of analgesia following knee arthroscopy
• Effective postoperative analgesia facilitates early
physical rehabilitation to maximize postoperative
range of motion and prevent joint adhesions
following knee replacement .
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55. The interscalene brachial plexus block
• By using ultrasound or electrical stimulation
• ideally suited for shoulder procedures
• Even when GA is employed, it can supplement
anesthesia for effective postop analgesia .
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56. • THANK YOU
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