NUR 730 Exam 4 Part 4 Study Guide PDF

NUR 730 Exam 4 part 4 study guide Spinal Cord Injury: ➔ Flexion injuries - anterior subluxation or fracture dislocations of the vertebral bodies ➔ Hyperextension injuries - transverse fractures of the vertebra, disruption of the anterior longitudinal ligaments, posterior dislocations ➔ Vertical...

NUR 730 Exam 4 part 4 study guide Spinal Cord Injury: ➔ Flexion injuries - anterior subluxation or fracture dislocations of the vertebral bodies ➔ Hyperextension injuries - transverse fractures of the vertebra, disruption of the anterior longitudinal ligaments, posterior dislocations ➔ Vertical compression -burst fractures and ligamentous rupture ➔ Rotational injuries -fractures of the vertebral peduncles and facets ➔ System effects of SCI ◆ Depends on the site or level of injury and phase - "why initial assessment is so important" Hypotension, bradycardia, hypothermia - "especially if C7 or higher" Bladder and bowel dysfunction Alteration in sweating Respiratory dysfunction C1-C3: complete injury will result in respiratory failure due to diaphragmatic paralysis ◆ All systems can be affected Treatment is aimed at: immobilization Medical stabilization Spinal alignment Operative decompression, and spinal stabilization ◆ She spoke a lot about this chart → "C1-4 - likely to be very unstable, high injury often expect bradycardia with suctioning - even when later" "Higher injuries may become asystolic from certain stimulation - like intubation" "Cardiac accelerator - T1-T4" "C7 injuries - minimal sympathetic function - still difficult to manage" ○ Injuries at C7 or higher: JUST INTUBATE THAT HOE!!\$\$!! ○ Patients with C7 injury are also unable to manage temp - hypothermia risk ➔ Evaluation and Assessment in ED ◆ ABCDE ◆ Airway management critical ◆ Neuroprotective strategies ➔ Acute Care of SCI ◆ External splinting and immobilization - initial "Immobilization and medical stabilization are kind of 'side-by-side' rather than separate" ○ "About 20% of SCIs are complete" ○ "Have to determine what their function is - it varies between types of incomplete" ○ "Spastic vs flaccid quadriplegia" ◆ Medical stabilization Airway management/oxygen delivery ○ Airway - may require intubation in the field or in the ED - "if not, why not?" ○ In-line manual cervical immobilization must be maintained during intubation ○ 100% Oxygen - RSI or Modified RSI ○ Supplemental oxygen - normal LOC, Gag reflex, patent airway ○ Blind nasal technique - not often used - "risk of basilar fractures" ○ Fiberoptic technique - non emergent - "if you're good at it use it" ○ ↑ C7→ respiratory failure ○ Neurogenic Pulmonary Edema (NPE) ◆ Pulmonary interstitial and alveolar fluid d/t acute CNS injury ◆ Develops within minutes to hours after a severe injury / insult ◆ Resolution usually begins within several days ◆ Signs & symptoms- dyspnea, tachypnea, tachycardia, basilar rales ◆ CXR- heart size normal with bilateral alveolar filling ◆ BP, CO, and PCWP (PaOP) - normal ○ Cardiogenic Pulmonary Edema (CPE) ◆ Increased capillary hydrostatic pressure secondary to elevated pulmonary venous pressure ◆ Accumulation of fluid with low-protein content in the lung interstitium and alveoli ◆ → Pulmonary veins and LA venous return → LV output Cardiovascular support ○ Initial substantial autonomic discharge - "compression of sympathetic nerves" ◆ Severe HTN and arrhythmias, LV failure, MI, pulmonary capillary leak ○ Usually not seen in the ED because hypotension occurs from spinal shock and hypovolemia - "usually out in the field" ○ Rhythm disturbances - bradycardia, primary asystole, SVT, Afib ◆ Resolve in 14 days Gastrointestinal ○ Acute SCI- GI tract atonic ○ Gastric distention ○ Risk for aspiration - "stomach will have in it what was in it at the time of injury - treat as full stomach" ○ Gastritis ○ Stress ulcers ○ Hypochloremic metabolic alkalosis ○ H2 blockers, antacids Genitourinary ○ Bladder - flaccid after SCI ○ Foley catheter → also to help ensure that they're not retaining" ○ Adequate hydration Temperature Control ○ At or above C7 - unable to conserve heat in a cold environment through vasoconstriction - "and they can't shiver" ○ Prone to hypothermia DVT prevention ○ Immobility → DVT (12-24%) and PE (10-13 %) ○ Mechanical compression devices, TED hose, and heparin ◆ Radiologic evaluation "Look at adequacy of alignment; MRI you can see soft tissues unlike with CT scan" ◆ Neuroprotective strategies Spinal alignment ○ Immobilization - "backboard, c-spine, etc." ○ Head tongs or halo traction devices for unstable injuries ○ Bed rest, log rolling for thoracic and lumbar fractures ○ Surgical interventions - "for things that immobilization won't help" ◆ Reduction, stabilization for dislocations that cannot be reduced by traction or manipulation ◆ Decompression within first 2 hours of injury - "best long term outcomes" Physiologic therapy ○ Cooling ○ Hypertension ○ Maintain stable glucose levels - "elevated glucose levels can be detrimental, esp with ischemia" ○ Nanomaterials - "chemical substances developed to get where they need to → help with inflammation, inhibitory factors, and promote axon regeneration" Pharmacologic therapy ○ Controversial and no longer used ○ Methylprednisolone - 30 mg/kg initially over 15 min ◆ 45 - minute pause ◆ Followed by an infusion of 5.4 mg/kg/hr for 23 hours, within the first 8 hours of injury ○ Mannitol - 0.25-1.0 g/kg ◆ "For inflammation: ○ "Corticosteroids" Surgical Reduction / Surgical Management ○ Decompression - \~2 hour = great success ○ Reduction and stabilization ○ Alignment ➔ Shock States in SCI ◆ Neurogenic Shock - hemodynamic phenomenon SCI above T6 S/s- Hypotension, bradycardia, vasodilation Caused by loss of sympathetic outflow below the level of the SCI Hypotension may be fluid resistant - "phenyl and \*norepi" ◆ Spinal shock - neurologic phenomenon Loss of motor, reflexes, sensation below level of injury Hypotension, bradycardia in initial phase May last hours - weeks ➔ SCI Symptoms ◆ Spinal cord injury → a concussion like injury to spinal cord within minutes of the injury ◆ Spinal Shock - total sensory and motor loss → NEUROLOGIC PHENOMENON Signs & symptoms - total loss of power, reflexes, sensation Lack of sympathetic outflow - ○ Flaccid paralysis, loss of reflexes below the level of the lesion, paralytic ileus, and loss of visceral and somatic sensation, vascular tone, and vasopressor reflex occurs ○ The lack of sympathetic outflow can cause vasodilatation, pooling of blood in peripheral vascular beds, postural hypotension and bradycardia Shock usually ends within 24 hours - may last longer Recovery→ hyperreflexia, hypertonicity, clonus Return of reflex activity ↓ injury → end of shock Minimal recovery with complete injury \> injury \> shock "Know: variety of s/sx and lack of sympathetic outflow" 4 Phases of Spinal Shock ○ Phase 1 - (0-1 days) - A complete loss or weakening of all reflexes below the level of spinal cord injury which usually lasts for a day. ○ Phase 2 - (1-3 days) → characterized by the return of some reflexes ◆ Polysynaptic reflexes- first reflexes to reappear ◆ Ex: Bulbocavernosus reflex → anal sphincter contraction ◆ S1, S2, S3 nerve roots - spinal cord mediated reflex. ◆ Signals the end of acute spinal shock ○ Phase 3- Initial hyperreflexia ◆ Deep Tendon Reflexes - return because of the hypersensitivity of reflex muscles following denervation "monosynaptic" ◆ More receptors for neurotransmitters are expressed and are easier to stimulate - "upregulation of receptors" ○ Phases 3 and 4 - ◆ Characterized by hyperreflexia Abnormally strong reflexes usually produced with minimal stimulation ○ Phase 4 - final hyperreflexia ◆ Rhythm disturbances Bradycardia, primary asystole, supraventricular dysrhythmias ○ Afib, SVT and ventricular dysrhythmias Caused by the disruption of sympathetic pathways in the cervical cord Resolve \~14 days Bradycardia- →functional sympathectomy ○ Interruption of cardiac accelerator nerves T1-T4 ○ Unopposed vagal innervation Resolves →over 3-5 weeks ○ Cardiac arrest →stimulation of the patient- Cardiovascular Problems from Spinal Shock ○ Hypotension → loss of sympathetic tone → vasodilation ○ LV impairment → autonomic imbalance ○ What would you see? "Pump problems", heart failure\*, reduced CO\* ◆ Neurogenic shock → HEMODYNAMIC PHENOMENON Devastating consequence of SCI ○ Associated with cervical and high thoracic spine injuries Early identification and aggressive management → vital to prevent secondary spinal injury ("inflammation, ischemia, etc") Other causes - spinal anesthesia, GBS, ANS toxins, transverse myelitis and other neuropathies ◆ Autonomic Dysreflexia (Hyperreflexia) Life threatening abnormal reaction of ANS to stimulation Occurs \~ 85% of patients with spinal cord injuries at or above T6 ○ Can occur in transections as low as T10 Can occur weeks to years after a spinal cord injury - "not just in acute phase, chronic SCIs as well" \~80% develop first episode within one year What happens? ○ Afferent impulses are transmitted to the isolated spine Afferent stimulation tolerated in healthy uninjured patients SCI → massive sympathetic response elicited → adrenal gland & SNS ○ Response is uninhibited by the brainstem and hypothalamus d/t injury Neural plasticity- ability of the nervous system to reorganize/ change its function, structure or connections in response to ("intrinsic or extrinsic") stimuli Physiology ○ Loss of supraspinal control over sympathetic preganglionic neurons ○ Vasoconstriction occurs below the lesion ○ Vasodilation occurs above the lesion ◆ Carotid and aortic arch baroreceptor activation ◆ ↓HR, ventricular dysrhythmias, and CHB from reflex activity Common symptoms include: ○ Severe hypertension, bradycardia, tachycardia, ○ Hyperreflexia, muscle rigidity and spasticity ◆ Profuse diaphoresis/sweating, ○ Changes in skin color -pallor, redness, blue-grey skin color, flushing above the lesion, ○ Intense headache ○ "Untreated can cause seizures" Less common ○ Horner's syndrome-aka oculosympathetic palsy- ○ Pupillary constriction, ptosis, decreased sweating Other causes : ○ Medication side effects - use of illegal stimulants such as cocaine and amphetamines ○ Guillain-Barre syndrome ○ Subarachnoid hemorrhage ○ Severe head trauma, and other brain injuries ○ "Usually a full bladder (ensure foley is draining) or stool impaction" What is the Treatment? ○ Stop the stimulus!! ○ Place patient in an upright position ○ Treat BP ◆ Administer medications - rapid onset/short duration ◆ Direct acting vasodilators - "sodium nitroprusside" ◆ Beta blockers ◆ Combined alpha and beta blocker - "labetalol" ◆ Calcium channel blockers - Nifedipine ◆ Ganglionic blockers ○ Prophylaxis and Acute Episodic Treatment ◆ Spinal Cord Part IV: considerations for surgical and anesthetic management of SCIs and diseases ➔ Anesthetic considerations for all patients with SCI or disease ◆ A thorough preoperative assessment is crucial - LOC, motor system, CN's, reflexes, deficits "Traumatic injuries - it may not be possible → know if they are stable or unstable, LOC, deficits, injuries, etc." ◆ Hemodynamic states - stable vs unstable ◆ Room setup Airway equipment- ○ Laryngoscope blades & handles ○ Oral airways - tongue depressors ○ Yankauer suction Monitors ○ Routine ○ Transducers for CVP, A line ○ Precordial doppler for sitting Emergency drugs - phenylephrine, ephedrine (+/-), atropine, glycopyrrolate (+/-) - "lidocaine is not an emergency drug" Eye tape and pads Induction and other Medications IVFs Equipment-Foley ◆ Induction and intubation What does the drug do to CBF, CBV, ICP? ○ Propofol - dose dependent drop; perk - rapid recovery ○ Etomidate - cardiac stable; avoid in trauma due to adrenocortical suppression ○ Ketamine - Intubation technique Anesthetic technique ◆ Monitoring ◆ Positioning ◆ Maintenance ◆ Emergence ◆ Postoperative care Extubation vs continued intubation/ventilation ○ Extubation ◆ Normal LOC preoperatively ◆ No respiratory problems or surgical complications ○ Continued intubation - "may be due to the patient requiring ventilation" ◆ Decreased LOC preoperatively ◆ Increased ICP ◆ Additional severe injuries VS stabilization ➔ Cervical Spine Surgery ◆ Done for cervical disc problems related to diseases, injuries and cervical instability. ◆ Positioning and airway management priority concerns ◆ Posterior cervical decompression -sitting or prone positions ◆ Anterior cervical decompression -supine position ◆ Intubation may be difficult Instability of the C spine or neck deformity - "maybe not just cervical spine pts, cervical spine disease" Airway assessment is essential - "can they move their neck, can they do so without symptoms?" Awake fiberoptic intubation - "laryngectomy, some use for any cervical spine surgery" Reinforced ETT ◆ Complicated by injury to the spinal cord during surgery leading to postoperative problems -- ◆ Intubation - in line neck immobilization Neutral position intraoperatively and postoperatively ◆ Upper airway edema post op - Excessive fluid Prolonged dependency "If you notice scleral edema be more cautious" ◆ Positioning and monitors Sitting position ○ CVP, Aline, routine monitors, 2 large bore IV's, precordial doppler with sitting, Bair Hugger, Fluid warmer, Foley, ? SSEP ○ Considerations for Sitting Position ◆ Advantages - surgical exposure, ventilation/airway access, possible blood loss reduction ◆ Disadvantages - VAE, hemodynamic instability, nerve damage What nerve injuries could occur? ○ Sciatic nerve damage ○ Mid Cervical nerve damage - "mayfield headrest - the surgeon adjusts flexion, ensure 3 fingers between chin and chest (document you told the surgeon)" What is the main contraindication to using this position and why? ○ R to L shunt - "intracardiac (PFO) or intrapulmonary" Venous Air Embolism- VAE ○ Massive air embolism → rare / catastrophic ◆ Air entrainment occurs slowly and over a longer period of time ◆ M&M related to volume of air and rate of accumulation - "3-5 ml/kg is deadly amount of air" ○ Abnormal collection of air/gas that forms in the systemic venous circulation & blocks blood flow ◆ \^ VAE risk ◆ Surgical site \> 20 cm above the heart ◆ Can also occur in the lateral and prone positions ◆ Sitting position + posterior fossa = VAE incidence \^ - 40-45% ◆ Sitting + cervical laminectomy or surgeries in prone, lateral = 10-15% ○ What happens in VAE? ◆ As air is cleared to the pulmonary circulation, PVR, PAP, and RAP ↑ ◆ Dead space ventilation ↑→↓ETCO2 and↑PaCO2. ◆ Nitrogen appears ◆ What will happen to HR and BP? ◆ ↓BP and ↑ HR ◆ Hypoxemia → partially occluded pulmonary vasculature & local release of vasoactive substances ◆ Untreated, CO ↓ d/t to right heart failure and/or reduced LV filling ○ Treatment ◆ Alert the surgeon to irrigate the field with saline → ◆ Simultaneously, CRNA is aspirating from the CVP catheter ◆ Discontinue N2O if in use and increase FiO2 to 100% ◆ Provide cardiovascular support if needed ◆ Compress both jugular veins lightly to minimize air entrainment ◆ Change patient position if above measures fail to prevent ongoing VAE ○ VAE can lead to PAE ◆ Air can pass to arterial side through a pulmonary vascular bed or PFO ◆ Embolization of a coronary or cerebral vessel ◆ This is known as a paradoxical air embolism 25% have probe patent foramen ovale & 40-45% incidence of VAE in the sitting position + posterior fossa surgery → 10 -12% risk of PAE What do we do differently? Prone position - +/- CVP, 2 large bore IV's, Bair Hugger, Fluid Warmer, Foley, ? SSEP Supine - 2 large bore IVs with routine monitors, Bair Hugger, Fluid warmer, +/- foley 0/4 TOF during "body" of case ➔ Considerations for Lumbar and Thoracolumbar Surgeries ◆ Lumbar Disc Surgery - lumbar laminectomy/fusion D/t trauma injury, disease, or HNP ○ Prone position ○ 2 large bore IV's ○ Routine Monitors ○ Upper body Bair Hugger ○ Fluid warmer ○ Foley catheter ○ 0/4 TOF during "body" of the case ◆ Thoracolumbar Spine Surgery Corrects deformity, stabilize fractures, or resection of tumors Positioning, spinal cord monitoring, minimizing blood loss, and postoperative respiratory care. Anterior and posterior procedures - can be staged or done at one time Anterior approach → thoracotomy incision → endobronchial aka double lumen ETT Positioning- head and neck ? - "midline (prone and lateral) - prevent compression" What else do we need to do? ○ Spinal cord monitoring ◆ SSEP ◆ Wake Up test or MEP Blood loss considerations ○ Autologous donation, cell saver, induced hypotension Monitors - what's needed? TOF 0/4 during "body" of case Postoperative care: ○ "Pain is huge" ○ "Fluids and blood - fluid shifts and hemodynamics" ➔ Chronic SCI ◆ Many of the same issues and problems as acute SCI ◆ Respiratory - ◆ Autonomic Hyperreflexia - ◆ Muscle spasms →hyperactive spinal reflexes ◆ "Mass reflex" Abnormal condition in spinal cord transection → widespread nerve discharge Violent muscle spasms Stimulation ↓lesion = flexor muscle spasms, incontinence, HTN, profuse sweating Triggers ○ Scratching & other painful skin stimuli ○ Overdistention of the bladder or intestines ○ Cold weather ○ Prolong sitting ○ Emotional stress Severe, violent muscle spasms Medical treatment - diazepam, dantrolene, etc. Surgical treatment - chordotomy, rhizotomy, peripheral nerve transection, or tenotomy Avoid stimulation Prevention of decubiti, bladder infections ◆ Anesthetic Considerations Regional vs. General - Is one better or worse? Hemodynamic control ○ Medications- direct acting vasodilators, alpha blockers, antihypertensives, antiarrhythmics, atropine ◆ Hyperkalemia in Chronic SCI and Succinylcholine ↑ risk of hyperkalemia with depolarizing muscle relaxants. Avoid succinylcholine. Upregulation of receptors at NMJ Dosing according to twitch response in a denervated limb → "overdose" of muscle relaxant Routine monitors plus others as per patient's condition and type of surgery Foley catheter - want to avoid urinary retention - "one of the easy things we can do" Extubation should be based on: the patient\'s underlying medical condition, surgical procedure, emergence response, and extubation criteria - "what were they doing before?" ◆ "Be very cautious with airway management and positioning"