2. Normal curves of spine
-In thoracic region spine curves posteriorly
kyphosis.
- In lumbar region spine curves anteriorly
lordosis.
3. - Complex deformity of spine
- Kyphosis -bowing of the back
- Scoliosis- lateral rotation of the spine greater than
10 degrees accompanied by vertebral rotation
- Abnormal curvature in both coronal and saggital
planes
- as well as deformity of rib cage
-secondary involvement of resp.,cardiovascular and
neurologic systems
-C shaped primary curve-weakening of vertebral
muscles
- Compensatory secondary curve-for centre of
gravity over pelvis.
DEFINITION
4.
5. - In general population- 0.3- 15.3%
-Most curves convex to the right
-Males are more likely to have infantile/juvenile scoliosis
-Females- adolescent scoliosis
PREVALENCE
6. 1.Idiopathic scoliosis-most common type(70%)
Cause unknown
a) Infantile 0-3yrs
b) Juvenile 4-10yrs
c) Adolescent >10yrs-most common
2.Neuromuscular scoliosis(paralytic scoliosis)
Neuropathic
Upper motor neuron(CP, spinal cord injury)
Lower motor neuron(poliomyelitis, meningomyelocele)
Familial dysautonomia
Myopathic
Muscular dystrophy
Myotonic dystrophy
TYPES OF SCOLIOSIS
7. 3. Congenital scoliosis
-Insult during intrauterine life
-Abnormality of development of vertebrae –
-Failure of segmentation
-Cardiac and urinary anomalies also
4. Neurofiromatosis mesenchymal disorders
-Marfan’s syndrome
-Ehlers Danlos syndrome
-Rheumatoid, osteogenesis imperfecta.
5. Trauma
-Vertebral fracture or surgery
-Post thoracoplasty
-Post radiation
8. • Postural kyphosis
– most common type
• Scheuermann's kyphosis
– a form of juvenile osteochondrosis of the spine
• Congenital kyphosis
• Nutritional kyphosis
– Vit D deficiency
• Gibbus deformity
– Tuberculosis
• Post-traumatic kyphosis
TYPES OF KYPHOSIS
10. • Back pain
• Leg length discrepancy
• Abnormal gait
• Uneven hips or waist
• One shoulder higher than other
• Prominent shoulder blade.
• Appearance of leaning to one side
• Increased space between the body and the elbow while standing in natural
posture.
• Chest/rib prominence
- Muscle tone- spasticity
Signs and Symptoms
11.
12. MEASUREMENT OF SCOLIOSIS
LIPPMAN COBB METHOD
Recommended by Terminology Committee of
the Scoliosis Research Society
Most commonly used
Cobb’ s angle
• < 10° : normal curvature
• > 25° : ECHO evidence of increased
pulmonary
artery pressure
• > 40° : surgical intervention required
• > 65° : restrictive lung disease
• >100° : dyspnoea on exertion
• >120° : alveolar hypoventilation
13. • Stand erect with feet together & knees fully extended &
palms touching each other
• Bending forward until back is horizontal
• Asymmetry of thoracic or lumbar spine may be detected with Scoliometer
• Measure Angle of Trunk Rotation(ATR) at thoracic ,thoraco lumbar & lumbar
areas of spine
ADAMS FORWARD BEND TEST
14.
15. PRE ANAESTHETIC ASSESSMENT
• Airway- difficult when upper thoracic or c
spine.
• Devices like halo traction may interfere with
securing airway.
• Duchenne muscular dystrophy- tongue
hypertrophy.
• Significant displacement or rotation of trachea
or main stem bronchi may cause mechanical
airway obstruction.
16. 2- RESPIRATORY SYSTEM
Any pre existing lung disease, pneumonia, severity of scoliosis.
Abnormalities in PFTs-
•Restrictive pattern is seen- ↓↓vital capacity( < 35% predicted)
•↓TLC,↓FRC,↓IC,↓ERV.
-decreased TLC and increased Residual volume very high RV/TLC ratio dysfunction of
expiratory muscles which do not allow full exhalation.
•FEV1/FVC remains normal*
•During exercise the ventilation is adequate but there is ↓TV and ↑RR . The maximum
work capacity decreases.
17. Cause of abnormal PFT
• Due to abnormal thoracic cage geometry leading to marked decrease in chest wall
compliance
-The lungs and respiratory muscles are normal
-except in congenital and infantile type where the growth of the lungs may be impaired.
18. BLOOD GAS ABNORMALITY IN SCOLIOSIS
- Arterial O2 desaturation( due to pulm shunting. )
- Increased alveolar arterial gradient.
- pCO2 and pH are normal
-Arterial hypoxemia is mainly because of ventilation perfusion mismatch.
-Prolonged periods of hypoxemia- pulm htn, hypercapnia and eventually resp failure.
-↓ diffusing capacity and alveolar hypoventilation may contribute.
-Severe long standing scoliosis is a/w marked V/Q mismatch, alveolar hypoventilation and
CO2 retention.
-If not surgically treated may lead to respiratory failure
21. TREATMENT OF KYPHOSCOLIOSIS
• To slow disease progression and prevent
complications.
• If untreated,idiopathic scoliosis often fatal in
4th or 5th decades of life as a result of p htn or
resp failure.
• Non surgical-braces, traction, plaster
applications
• surgical
22. SURGICAL PROCEDURE
• Indication- documented progression of Kyphoscoliosis curvature at
any age.
• Aim- to prevent progression of ks, pulm dysfunction,cv disease.
• - to maintain posture.
• If ks due to neuromuscular problems-angle of curvature 25 degree
• In ks due to non neuromuscular problems- 40 degree.
• Decortication & maintaining correction till bony fusion with the
help of instrumentation
• Erector spinae, spinous process, intraspinal ligament, facet joint
removed
• Vertebrae decorticated & bone graft placed
Surgical approaches
-Posterior approach
- Anterior approach
- Combined / staged
23. Nature of spinal curve
• Location of curve-thoracic scoliosis is a/w ↑PFT abnormality and cervical scoliosis
with difficult airway.
• Age of onset-early onset scoliosis may be a/w ↓alveolar number and impaired gas
exchange.
• Severity- >60 related to decrease pulmonary function and >100 to impaired gas
exchange.
• Etiology-may be a/w other diseases-MV regurgitation and prolapse(25%),congenital
hrt dis.
PREOPERATIVE EVALUATION
24. History
•H/O SOB, DOE and effort tolerance to asses the cardiopulmonary reserve.
•H/O cough or wheeze to see association with any parenchymal lung disease.
•Pt of marfan’s and neurofibromatosis may have symptoms of palpitations and
syncope because of underlying cardiac conditions.
25. Physical examination
•Auscultation of lungs for any wheeze (obstructive or parenchymal lung disease)
•Heart-signs of PAH(loud P2)and signs of RVH(engorged veins, hepatomegaly, edema)
•Skin-café au lait spots in NF
•Airway assessment-to see for cervical scoliosis, high arched palate(Marfan’s).
•Neurological assessment-pt with pre existing neurological deficit are at ↑risk of spinal
cord injury during surg.
Also documentation of pre op neurological status is imp.
29. Preop optimisation
• Need for postop ventilation explained
• Preop spirometry
• Bronchodilator therapy
• Hydration
• -breathing exercises
• Preop counselling for wake up test
31. Monitoring & lines
• Two wide bore iv lines
• Standard ASA monitoring : ECG, NIBP, SpO2,vapour pressure, EtCO2,
Airway pressures
• Invasive blood pressure, CVP monitoring( not reliable in prone position
or with open chest)
• Urine output, temperature
• Warm fluids, warm blanket
• Eye care, pressure points & positioning
• Esophageal stethoscope
32. • Premedication- avoid narcotics, heavy sedation. Anti sialogogues
• Induction- routine i.v or inhalational
• - myopathies- no suxa ( hyperkalemia)
• -suxa- Malignant Hyperthermia in King Denborough
syndrome, Adenylate kinase deficiency.
• Intubation- DLT if anterior approach
• - SLT with reinforced tube and prone position if posterior
approach
• Maintenance- proper depth for interpretation of evoked potentials.
• - N2O + narcotic + volatile technique or propofol
• - when MEPs are recorded-use atrac by infusion and
maintain constant depth of block by NM monitoring
33. - Arms are abducted less than 90 degrees whenever
possible(prone “superman” position)
-Peripheral nerves, eyes, genitals and bony points are
padded
- Soft head pillow has cut outs for eyes and nose and a slot
to permit endotracheal tube exit
- Chest and abdomen are supported away from the bed
- minimize abdominal pressure and preserve pulmonary
compliance
- Eyes checked frequently
-Elastic stockings and active compression devices-lower
extremities -minimize pooling of the blood
-Intraop imaging is often required
-Anterior approach to T-spine- via thoracotomy with
patient in lateral position. Anterior approach to L-spine
through laparotomy.
34. Intraoperative concerns
• Blood loss & replacement
• Hypothermia
• Prone position complications
• Lung isolation
• Spinal cord monitoring (Wake up test & evoked potentials)
• Venous air embolism
35. To reduce blood loss-
1) In prone position- minimise intra abdominal pressure
2) Hypotensive anaesthesia- MAP at 60-65 mmHg
- volatiles, Na Nitroprusside, Ganglionic blocking drugs(
trimethaphan), CCBs ( nicardipine), beta blockers (labetolol), NTG, Fenoldopam.
3) Anti fibrinolytics- aprotinin
36. • Techniques to reduce loss
– Avoid light anaesthesia, hypertension, hyperdynamic circulation, hypercapnia
– Surgical hemostasis & vasoconstrictor use
– Proper positioning – avoid raised intra abdominal pressure
– Deliberate controlled hypotensive anaesthesia
– Pharmacological agents
Blood loss & replacement
• Usually associated with large blood losses– 15 to 20 ml/kg
• Risks with allogenic transfusion like hypothermia, impaired coagulation, hyperkalemia...
37. • Young healthy patient - mean arterial pressure of 50 to 60 mm Hg
• Adult patient with cardiovascular disease : higher pressures
• Pre requisites : invasive BP & urine output, ABG
• Techniques:
- high dose inhalational agent
- vasodilators: Na nitroprusside, nitroglycerine
- Ganglionic blocking agents-trimethaphan
- B adrenergic blockers: esmolol, labetalol
- ACE I: captopril
-ᾳ2 agonist: dexmedetomidine
*concern- ↓SC blood flow ↑ chance of SC injury
Deliberate controlled Hypotensive Anaesthesia
38. Pharmacological agents
-Aprotinin
◦ Reduces blood loss in spine surgeries
◦ Inhibits plasmin & kallikrein and preserves platelet function.
◦ 1-2 million KIU bolus - 0.25-0.5 million KIU/hr
- Desmopressin
- Tranexamic acid 10mg/kg infusion @ 1mg/kg/hr
39. Preoperative autologous blood donation
- Hb> 11g%, HCT> 33%
- No age / weight limits
- Donate 10-15% of blood volume
- Start 3-5 weeks before surgery
- 2 donations(1/week)
- Last donation no less than 72 hours before surgery
- Recombinant Erythropoietin supplementation
40. Acute normovolemic hemodilution
- Removal of whole blood shortly before anticipated significant blood loss
- Collected in standard blood bags with anticoagulation
- Simultaneous infusion of crystalloid(3:1) or colloid(1:1) to achieve Normovolemia with
reduced hematocrit.
- Stored at room temperature
- Re infused during surgery after major blood loss has occurred and after hemostasis is
achieved.
- Re infused in reverse order of collection
41. Blood salvage
- Blood lost during surgery is collected using commercially available equipment and is
then anticoagulated, filtered for clots and debris,centrifuged,
- resuspended in saline and reinfused to the patient.
- Clotting factors need to be replaced using fresh frozen plasma.
- The technique is unsuitable in the presence of malignancy or infection
42. Hypothermia
- Long duration of surgery
- Transfusion of blood & blood products
- Hazards
◦ Impaired coagulation
◦ Wound infection
◦ Delayed recovery
◦ Acid/base changes
- Prevention
◦ Monitoring , warm fluids, warming blankets, warm irrigation solutions
43. Spinal cord monitoring
- Postoperative neurologic deficit is one of the most feared complications
- Varies with type of instrumentation
◦ Harrington rod- 0.23%
◦ Lugue correction- 1%
◦ Cotrel dubousset )- 0.6%
-Thoracic circulation- WATER SHED (T4-T9)
-Autoregulation of spinal cord blood flow disturbed by- distraction of spine, pedicle
screws, bony decompression, intraop events.
- depends on perfusion pressure– Hypotension may worsen this.
-Therefore tests to safeguard spinal cord function during surgery.
44. Spinal cord monitoring
Wake up test
◦ Gold standard
Somatosensory evoked potentials(SSEPs)
◦ Evaluate posterior/sensory portion of the cord
Motor evoked potentials(MEPs) & electromyograms
◦ Integrity of anterior motor spinal cord
45. Wake up test
- Gross test but most reliable for intact spine
- Explaining procedure prior to surgery
- Repeat/enact before induction
- Switch off inhalation & MR. 2-3 twitches on TOF is sufficient.
- Maintain on opioid
-for prompt awakening intraop- tiva with propofol and sufentanyl/remifentanyl OR
-N2O/O2/iso with switch to sevo.
-not advisable to reverse neuro muscular blockade or narcotics to speed up the Wake up
test.
-First asked to grip hand, then wriggle toes
- Preparation to restrain any unwanted movement
46. Wake up test Hazards & disadvantages
◦ Results influenced by anaesthetics and the cognitive integrity of the patient
◦ inadvertent extubation of the patient during movement in the prone position
◦ air embolism during a deep inspiration
◦ dislodgment of the instrumentation during violent movements
◦ Injury
-increased duration of surgery.
-info about neural damage only upto the time test was performed. Damage occuring later is
missed.
47. SSEP
-Evaluate posterior/sensory portion of the cord
- Stimulation of peripheral nerve by surface electrodes placed on skin above the nerve
- Posterior tibial at ankle or common peroneal at knee
- Square wave stimulus of 50-250 mic sec , 20-50mA, 16Hz
- Recorded from scalp or cervical/thoracic epidural electrodes
- Increased latency>10-15% &decreased amplitude >50 % significant
- Muscle activity disturbance eliminated by NMB
- Affected by hypotension, hypothermia, hypocarbia, hypoxemia, anemia, and anesthetics
Adv-continuous intraop monitoring of post columns.
Disadv-will not detect damage to the motor pathways
48. -Can use volatiles upto 1 MAC- no effect on SSEP
-Opiods have least effect on SSEPs
-If MAP < autoregulation SSEP amplitude decreases.
-Hypothermia increases latency
-Hyperthermia decreases amplitude. Loss of wave at 42 degree centigrade
-Hypoxia- decreases amplitude.
49. MEP
- Assess the integrity of the spinal motor pathways (anterior columns )
-direct stimulation of exposed cortex or trans cranial cortical stimulation or magnetic cortical
stimulation.
- Epidural , neurogenic or myogenic MEP
- Conduction of these stimuli through the motor pathways is monitored as peripheral nerve
impulses, electromyographic signals, or actual limb movements.
-More sensitive to anesthetic interface compared to SSEP
-Demand s a rigid anaesthesia protocol
- minimum dose of ketamine infusion OR
-Titrable infusion of Droperidol-fentanyl
-* Muscle relaxants have no effect on SSEP or MEP
51. Pain management (multimodal analgesia)
-PCA with opiods + nsaids or BZDs
-Parental opioid (48 hours)
◦ continuous infusion/iv PCA
-NSAIDs
◦ Opioid sparing effect
◦ Reports that ketorolac inhibits spinal fusion
-Epidural infusion
◦ Local anaesthetic + opioid infusion
-Intrathecal opioid-low dose intrathecal morphine (2-5 mic/kg) by surgeon.
No late resp depression but continuous monitoring of resp for 24hrs.
- others- intra pleural infusions of local anaesthetics or opioids or both
- Low dose IV ketamine- bolus of 0.25 mg/kg followed by infusion
22.5mic/kg/min
52. Optimisation of pulmonary status
-Incentive spirometry
-Coughing and deep breathing should be encouraged
-Bronchodilators therapy if reactive airway disease also present
-Adequate analgesia
53. Predictors of post op ventilation
- Patient factors
- Severe restrictive lung disease
-Vital capacity< 35%
-PaO2 < 60 mmHg
- PaCO2 > 50 mm Hg
- Right ventricular failure
- Pre existing neuromuscular disease
- Congenital heart disease
- Obesity
Surgical factors
◦ Blood loss > 30 ml/kg
◦ Surgical invasion to thoracic cavity
54. Summary
• Scoliosis may be of varied etiology.
• Respiratory and cardio vascular involvement is
common.
• Needs detailed pre anaesthetic evaluation and
optimisation.
• Very challenging and complicated surgical procedure.
• Intraop monitoring, temperature and fluid balance,
positioning, spinal cord integrity monitoring and blood
conssrvation
• Postop intensive care, respiratory care and pain
management.
