TRAUMA TO SPINE ROLE OF ANAESTHESIOLOGIST

1. TRAUMA TO SPINE ROLE OF ANAESTHESIOLOGIST Speakers Ranju Gandhi KalaiSelvan Moderator Dr Bhalla www.anaesthesia.co.inanaesthesia.co.in@gmail.com

2. Role of Anaesthesiologist • Acute phase • Resuscitation in emergency department • Airway management • Administration of anaesthesia for acute decompression of spinal cord to preserve or improve function • Administration of anaesthesia for surgical treatment of associated injuries II. Chronic phase

4. Pharmacological Agents for spinal cord injury

5. Recommendations of three NASCI studies for MPS in treatment of acute spinal cord injury • Methylprednisolone bolus, 30 mg/kg,then infusion at 5.4mg/kg/hr • Infusion for 24 hr if bolus given within 3 hr of injury • Infusion for 48 hr if bolus given within 3-8 hr after injury • No benefit if MP started more than 8 hr after injury • No benefit with naloxone • No benefit with tirilazad

6. Goal of treatment of spinal cord injuries • Protect spinal cord from further damage (secondary injury) • Maintain alignment of bony structures to allow maximum recovery in incomplete leisons • Achieve stability of bony column to allow rehabilitation

7. Management techniques for spinal injuries • Can be nonoperative or operative • Non operative management consist of immobilization that is well tolerated, permit timely mobilization & allow for healing within a reasonable period • Cervical spine injury : Cervical traction with head halter, tongs or a halo ring or cervical braces(CO & low & high CTOs)

8. Management techniques for spinal injuries • Full contact TLSO is currently most effective orthosis for management of patients with thoracolumbar #es • Below L4 Spica TLSO with 15-30 deg hip flexion • Above T8 Spica TLSO with custom moulded cervical extension • Special beds :For optimal reduction & prevention of 20 complications “egg crate mattress” & special rotating beds (Stryker bed & Rotorest frame)

9. Surgical management of cervical & Thoracolumbar injuries • Principal goal is adequate decompression of neural elements to allow maximal restoration of neurologic function • Optimal timing of surgery early vs late is controversial • Only absolute indication for immediate or emergency surgery is progressive neurologic deterioration in patients with incomplete or no neurologic deficit or other life-threatening conditions, unrelated to cord injury

10. Anaesthetist’s concerns in Acute phase (Preoperative assessment) • CVS : Spinal shock, Baseline HR, BP, Arrhythmias, need for inotropic support • RS :Respiratory insufficiency, chest infection • Mid to low cervical spine injuries (C4-C8) spare the diaphragm- intercostal & abdominal muscles may be paralysed.This leads to inadequate cough, paradoxical rib movement on spontaneous ventilation, ↓ VC by upto 50% (redn in IC to 70% & ERV to 20%), ↓ in FRC to 85% 0f predicted, & loss of active expiration. Manel et al.Respiratory complications & management of spinal cord injuries. Chest 97 :1446-52. OPTIMIZE RESPIRATORY FUNCTION BY TREATING ANY REVERSIBLE CAUSE, INCLUDING INFECTION, WITH PHYSIOTHERAPY & NEBULIZED BRONCHODILATORS

11. Anaesthethist’s concerns • CNS : Level of injury, complete or incomplete • Airway : unstable cervical spine, potential for difficulty if leison at cervical or upper thoracic spine • Immobilization devices • Increased risk of venous thromboembolism : Initiate LMWH or mechanical prophylaxis with pneumatic boots or compression stockings • Delayed gastric emptying • Impairment of thermoregulation • Investigations : Routine hematological, Cervical spine X rays, CXR, ABG, Spirometry, ECG

12. Preparation & Premedication • Explanation of awake intubation, Wake up test, need for post op ET • High spinal cord leison or FOI: anticholinergic atropine or glycopyrrolate (200-400µg iv or im) Antiaspiration prophylaxis: H2 receptor antagonist, or a proton pump inhibitor, with sod. citrate

13. Induction • Can be very challenging, particularly with unstable cervical spine #es & incomplete neurologic deficit • Maintaining alignment of cervical spine during intubation is vital in preventing neurologic deterioration • Awake fibrescopic intubation is safest (if surgery is non urgent) Use nebulized lidocaine rather than cricothyroid inj or admn of local anaesthetic through fibre-optic scope

14. Induction • IV or inhalation guided by patient’s condition & ease with which trachea may be intubated • Preoxygenate • Hypoxia or manipulation of larynx or trachea can cause profound bradycardia • All drugs given slowly by titration because of cardiovascular lability • Succinylcholine can be used in first 48 hours & again 9 months after injury (Hambly et al. Anaesthesia 1998)

15. Intubation

16. Review of literaure • McCoy laryngoscope significantly improves view at L’scopy (Gabbot et al Anaesthesia 1996) • Bullard L’scope may be useful adjunct to intubation of patients with potential cervical spine injury when time to intubation is not critical (Andrew et al Anaesthesiology 1997) • Intubating Laryngeal Mask & RSI in patient with cervical spine injury (Schuschnig et al Anaesthesia 1999) • Awake tracheal intubation through ILMA in a patient with halo traction (Bengi et al CJA 2002)

17. Review of literaure • Upper airway obstruction by retropharyngeal hematoma after cervical spine trauma. Report of a case treated with Percutaneous Dilational Tracheostomy(Mazzon et al J of Neurosurgical Anaesthesio 1998) • Use of ILMA to facilitate awake orotracheal intubation in patients with cervical spine disorders ( Wong et al J Clin Anesth 1998) • Anesthetic management of a patient in prone position with a drill bit penetrating the spinal canal al C1-C2, using LMA (Valero et al Anesth analg 2004) • Trauma in pregnancy:anaesthetic management with awake FOI with unstable cervical spine ( Kuczkowki et al Anaesthesia 2003)

18. Intraoperative monitoring • Routine : ECG, HR, SpO2, NIBP/IBP, Et CO2, Temp, UO, NM, AWP, CVP Special : Neurophysiological • Wake up test • SSEP • MEP ICP : Associated head injury PAC : Spinal shock Prone position : TOE, CVP or PAOP misleadng indicators of aequate cardiac filling

19. Positioning : A delicate endeavor • Depends on level of spine to be operated on & nature of proposed Sx • Peripheral nerves, bony prominences & eyes are protected & padded • Proper positioning of upper extremity • Avoid displacement of unstable #es • Logrolling from trolley to table • Compression stockings on lower extremities • Thoracolumbar surgery • Anterior approach right decubitus position, may require DLT • Posterior Sx Prone with free abdomen • Disc Sx Knee-chest position

20. Positioning • Cervical Sx : Anterior approach • Feet close to anaesthetic machine for surgical access to head & neck • Extensions needed to breathing circuits & iv lines • Tracheal tubes carefully secured without impinging on surgical field • Reinforced tube • Head supported on padded head ring or Horseshoe of Mayfield NSical OT attachment & axial traction with head halter or skull tongs traction • Shoulders retracted distally & secured with longitudinal tape to facilitate radiographic access • Reverse trendelenberg minimizes venous bleeding & provides counter traction for weight attached to head

21. Posterior approach to cervical spine • Patient turned prone with longitudinal chest rolls • Turning can be facilitated with Stryker frame • Head supported on gel-padded horseshoe of Mayfield table attachment or skull clamp • Orbits, superior orbital nerve & skin over maxilla at risk of ischaemic injury • VAE is a risk

22. Maintenance • Stable anaesthetic depth • 60% N2O & isoflurane < .5 MAC, opioid • Recommended to keep MAP between 80-90 mm Hg (to maintain adequate SC perf) • Warming of all IVF & warm air mattress device • Sudden cardiovascular instability- SC & BS reflexes, mediastinal distortion bcoz of surgical manipulation or blood loss

23. Blood Loss • Depends on number of spinal levels operated, body weight, Preop Hb (Zheng et al Spine 2002) • Raised IAP in prone position • Associated with increased operative time, delayed wound healing, wound infections, increased requirement of BT & associated risks • Can be minimized by careful patient positioning, good surgical technique, controlled hypotensive anaesthesia & use of antifibrinolytics(aprotinin, tranaxemic acid, EACA) • Autologous blood : Pre-deposit autologous transfusion, ANH, intraoperative RBC salvage

24. Intraoperative Spinal cord monitoring • Ankle clonus test Performed during emergence SCI : Complete absence Hoppenfeld et al. J Bone Joint Surg Am 1997 Reported 100% sensitivity & 99.7% specificity Can be performed intermittently & absence can be due to inadequate or too great anaesthetic depth

25. Stagnara wake-up test • Simple, cost effective & reliable test • Evaluates gross functional integrity of motor pathways • Preoperatively, need for test is explained • Limitations : Doesn’t evaluate sensory function & PROVIDES NO INFORMATION REGARDING SPECIFIC ROOT INJURY • Disadvantages : • Requires patient cooperation • Poses risks to patient & tracheal extubation • Requires considerable operator skill • Doesnot allow continuous IOM of motor pathways • Risk of VAE

26. Somatosensory evoked potentials • Elicited by stimulating electrically a mixed peripheral nerve, & recording responses from electrodes at distant sites cephalad to level at which surgery is performed. • Functional integrity of somatosensory pathways is determined by comparing amplitude change & latency change of responses obtained during surgery to baseline values. • Reduction in amplitude of response by 50% & increase in latency by 10% is considered significant.

27. Postoperative care • Close monitoring of vitals, neurologic function, any worsening suggestive of epidural haematoma • Observation of upper airway for local edema, wound haematoma esp after anterior cervical spine injury • Use of orthotic devices further restricts excessive spine motion, allows for soft tissue healing, & decreases pain • Initiate DVT prophylaxis (mechanical )

28. Postoperative analgesia • Multimodal approach recommended • Combination of NSAIDs, opioids and regional anaesthesia techniques where appropriate • Reuben et al . J Bone Joint Surg. 2005 . Effect of COX-2 inhibition on analgesia & spinal fusion • Parenteral opioids mainstay of analgesia via im,iv ( continuous infusion & PCA devices with or without background infusion), intrapleural, epidural, & intrathecal routes

29. Gunshot wounds of spine • Patient evaluation • ABC • General description of weapon (handgun, rifle, assault weapon) • Examination of entrance & exit wounds • Palpation to assess presence of crepitation & general turgor of tissue

30. Radiographic examination • Fracture type & degree of bone comminution • Bullet in torso & extent of bullet fragmentation • CT scan : extent of spinal injury & degree of spinal canal encroachment by bone or bullet fragments • MR scans not routinely performed If projectile is ferromagnetic, there may be further local tissue damage.

31. Treatment of Gunshot wounds of spine • Wound care • Exploration of wounds of neck, chest & abdomen only in patients with specific warning signs of serious injury • Minimally invasive surgery with arteriography & use of intravascular hemostatic coils has changed indications of em exploratory surgery • Use of steroids is contraindicated

32. Treatment of Gunshot wounds of spine • Wound cultures should be taken from bullet tract • Uncontaminated spinal injuries: 3 days of treatment with parenteral antibiotics • Contaminated wounds: 7-14 day antibiotic regimen recommended • Rarely require operation for establishing stability.

33. Associated viscus injuries • If bullet first penetrated pharynx, esophagus or colon before entering spine, extra precautions taken to prevent spinal infection • Em surgery for repair of viscus & broad spectrum antibiotics

34. Bullet in disc space • Indications of surgery • Patient likely to develop lead poisoning • Disc extrusion causing significant neural compression which is symptomatic Bullet in spinal canal Surgery indicated • All patients with cervical injuries • Documented compression of neural elements by bone, disc, bullet or haematoma • At 7-10 days unless deemed urgent

35. Complications of gun shot injury to spine • Neurologic injury • CSF fistulas • Subarachnoid pleural fistula • Spinal infections • Chronic dysesthetic pains

36. Chronic phase • Preoperative evaluation : Problems • CVS : Autonomic hyperreflexia, ↓ blood volume, orthostatic hypotension • RS : Muscle weakness, ↓ cough ability, retention of secretions, atelectasis • Neuromuscular : Proliferation of EJ Ach receptors, spasticity • Genitourinary & Renal : Recurrent UTI, altered bladder emptying, VUR, Early nephrolithiasis

37. contd • GIT : Gastroparesis, ileus • Skin : Decubitus ulcers, difficult venepuncture (skin atrophic, ↓BF) • Hematologic : Anaemia, DVT (25%) • Bone : Osteoporosis, hypercalcemia, muscle calcification, hypercalciuria • Nervous system : Chronic pain • Metabolic : Glucose intolerance, insulin resistance, high i of atherosclerosis (↓ HDL & increased TGL) • Impaired thermoregulation

38. Types of Sugeries • Urological procedures • Pressure sores • Orthepedic surgery for spinal fixation & treatment of fractures • Neurosurgery : Insertion or removal of intrathecal baclofen infusion apparatus, insertion of SC stimulators & phrenic n pacing • Msc : Coincidental SX

39. Autonomic dysreflexia • 3-6 weeks after SCI-------12 years • Characterized by extreme autonomic responses after stimulation of nerves below level of spinal cord leison (rectal, urological, peritoneal) • Vasodilation in areas above the leison & vasoconstriction below. • Prevalance of 60-80% in leisons above T6 • Results from disorganized connections b/w pre-synaptic afferent terminal buttons & interneurons within SC which synapses with sym efferents • Increased sensitivity to exogenous vasopressors • Adverse sequealae : Myocardial ischaemia, ICH, Pulmonary edema, seizure, coma, death

40. Management of autonomic dysreflexia • Removal of precipitating stimulus • Exclude bladder distention & fecal impaction • Pharmacological interventions (Alfa 1, alfa 2, β) Blockers, labetalol, CCBs, ganglion blockers, nitrates, hydralazine, reserpine, Magnesium Perioperative Autonomic dysreflexia (Laurie et al Anaesthesiology 2004) Preanaesthetic history of AD if +ve, greater chance of developing intraop. Frequency of AD during CNB low, compared to GA During general anaesthesia : increase anaesthetic depth

41. Regional anaesthesia in autonomic dysreflexia • Spinal anaesthesia recommended • Cardiostability in various studies • Does not affect neurological outcome • Epidural opioids (pethidine) to prevent autonomic dysreflexia • Epidural analgesia, CSEA during labor • SAB, EPIDURAL, GA for LSCS • Brachial plexus block for UL Sx

42. Chronic pain after SCI • 2 types of neuropathic pain : • Segmentally distributed pain at leison (n root entrapment or direct segmental deafferentation) • Pain in body below leison, late onset • Shoulder pain in tetraplegia (incidence 70% - Spinal Cord 2006) • Partial spinal leisons, specially cervical more prone to produce pain than complete leisons

43. Chronic pain after SCI • Treatment • Analgesic effect of iv ketamine & lidocaine on pain after SCI ( Acta Anaesthesiolog Scand 2004) • The efficacy of intrathecal morphine & clonidine in treatment of pain after SCI (Anesth Analg 2000) • SSRI, Gabapentin, Amitryptiline, Carbamazepine, Baclofen • Interventional spine therapy • Dorsal root entry zone (DREZ) leisoning procedure under intramedullary electrical guidance improves pain outcomes in patients with traumatic SCI ( J Neurosurg 2002) • TENS, Acupuncture, SC stimulation • Cognitive behavioural rehabilitation www.anaesthesia.co.inanaesthesia.co.in@gmail.com