Neurological Emergencies PDF

Nursing Lecture -- 11 **Components of Neurologic Examination** - Mentation - Gait & posture - Cranial nerves - Postural reactions - Spinal reflexes **Neurologicalization** - Also known as :neuroanatomic diagnosis' - Findings of neurologic examination results in this - Consi...

Nursing Lecture -- 11 **Components of Neurologic Examination** - Mentation - Gait & posture - Cranial nerves - Postural reactions - Spinal reflexes **Neurologicalization** - Also known as :neuroanatomic diagnosis' - Findings of neurologic examination results in this - Considers patients signalment and history - Allows medical team to generate a list of differential diagnosis Then a diagnostic and treatment plan **Taking a Thorough History** - Important to take a meticulous history - Vet tech is the first observer of changes in a patient's neurologic state - Carefully observe the patient - Physically test reflexes and responses of the patient - Attempt to localize the problem to a specific anatomic region within the nervous system **History of Components** - History of chief complaint - Medical history, including: reproductive status copies of vaccinations - Environmental history **Overall Therapy View for Neuro ER** - Changes in mentation, vitals, posture, reflexes etc can suggest decompensation - Changes in mentation or brain stem injury can cause altered breathing or loss of spontaneous ventilation - Monitor RBC, hemoglobin levels (transfusion as needed) - Monitor blood gases, saturation of oxygen maintain \>98% - trauma may have resulted in damage to other organ systems, ventilation & oxygenation are related -- if one is bad the other will be eventually Control of Pac02 (partial pressure of arterial carbon dioxide) **Seizures** 3 main causes of acute episodes of animals behaving strangely - Intoxications - Seizures - Metabolic illness - Originate in the brain Types include - Tonic - Clonic - Atonic - Myoclonic - Absence Focal Seizures -- petit mal and simple/complex partial seizures Generalized seizures -- tonic clonic seizures - Stiff movement of limbs - Loss of consciousness - Opisthotonus (arching of neck and back), chewing, hypersalivation - +/- urination/defecation Status epilepticus -- seizure avtivity continuing for 20 mins or more Any seizure longer than 5 mins in duration is too long Clusters (3-4 in 30mins, or numerous over a day) abnormal Status (does not regain consciousness between seizures Treatment - Emergency treatment is indicated to stop seizure activity - High frequency seizures should also be treated aggressively - Therapeutic approach depends on whether these are patients first seizures or if epilepsy has been previously diagnosed Need to stop Seizures ASAP How Serious Concerns if not - Diazepam is first choice - Neurologic - IV catheter if possible - Cardiovascular - IV Diazepam (bolus) - Resp - If IV rout is not accessible -- rectal diazepam - Renal - takes approx. 3 mins to total effect - Metabolic - repeat if needed, can administer as a CRI For Patients not Responsive to Diazepam - Induce general anesthesia -- light plane, enough to stop seizure - Drugs may be use -- IV phenobarbital or levetiracetam (Keppra) - +/- inhalant -- e.g Isoflurane - It is recommended that patients be intubated -- protects airway, 100% oxygen - Give as singular injection or CRI Managing the 2 Effects of Seizures - IV fluids -- often dehydrated, electrolyte imbalance, hyperthermia (most common side effect) - Watch for petechial hemorrhages -- thrombocytopenia, DIC - Non-cardiogenic pulmonary edema can be from Hypoglycemia Hypoxia Resp arrest Nursing Care -- Seizure CRI patients - Constant or frequent observation important - TPR/prn, hourly, BP, important & mini neuro exam Mentation, pupils important - Monitor 02 -- supplement if necessary, +/- intubate - IV must be excellent -- checked frequently - Turning & changing position - Bedding or padding - Ocular lube essential - Bladder cath, mouth care **Spinal Cord Injury** Proprioceptive Ataxia - Conditions in which the animal does not know the location of its paws or body space Loss of Nociception -- tested by clamping on a toe with a pair of hemostats - Causes can be divided into intrinsic versus extrinsic Weakness in the Limbs (paresis) results from loss of motor neuron instructions to muscles - Sinking while standing or walking - Crouched stance - Difficulty rising - Scuffing paws while waling - Decreased or complete loss of voluntary movement There are 3 ways a disc can impinge upon the spinal cord - Degenerative changes affecting the nucleus pulposus - Degeneration that involves weakening and thickening of the annulus fibrosus - Acute nucleus pulposus extrusion At hospital: - Limit movement (keep on back board), perform PE & Neuro exam - IV access - Pain control after neuro exam - Treat any cardiovascular resp, shock concerns - Watch for changes On Presentation with Spinal Cord Injury -- mentation and cranial nerves will be normal Key deficits are -- abnormality of gait & spinal reflexes Presence or absence of spinal pain Abnormality of Gait -- moving oddity = ataxic Weak = paretic Not moving at all = paralyzed Treatment for Spinal Cord Injuries - Complete neurologic examination - If no voluntary movement test nociception - Work up -- blood work, rads, +/- MRI/CT scan - Provide analgesia if patient is in pain Opioids for severe pain & anti-inflammatories - IV corticosteroids -- large initial dose ASAP after injury -- controversial - Strict cage rest or surgical treatment - May be recumbent - Urination/defecation care -- keep clean, dry, u-cath is often best option **Head Trauma** - Fairly common - Usually with a history of being HBC or other object, or falling from height - Acute neurologic exam findings will depend on site of brain injury - Brain injury occurs in 2 stages Primary brain injury as direct response of trauma Secondary injury as a sequel How to asses for traumatic brain injury pg 314 Pupils - PLR -- decreased responsiveness, asses direct & consensual - Size -- Miosis (excessive pupil constriction) Moderate brain swelling - Mydriasis (dilation of pupils) Marked brain swelling, high sympathetic tone Fixed, dilated pupils with altered mentation = TBI - Anisocoria (unequal pupil size) Acute cerebral lesion is possible Mentation - \(A) Alert - \(V) Verbally Responsive - \(P) Responds to Pain - \(U) unresponsive -- comatose or seizure Posture - Opisthotonus -- arching of the back, with the neck extended and the top of head is pointed toward the mid-back = BAD - Schiff Sherrington Posture -- Extensor rigidity in the front legs BUT normal proprioception with hind paralysis = BAD - Decerebrate Posture -- paralysis, all 4 limbs rigid and extended Any Injuries -- What do We Look For - Lacerations, abrasions, head/skull fractures - Proptosis, epistaxis, blood in aural canal - Hyphema (blood in front chamber of eye), scleral hemorrhage Other -- vestibular imbalance, nystagmus. Tremors, paresis, paralysis Treatment - To help localize lesions and prognosis - Make assessments with attention to mentation - Often accompanies by systemic injuries - Direct therapy to reduce increased ICP & improve cerebral blood flow with drugs - Mechanical ventilation may be required - Steroids sometimes used as last resort With head traumas the brain swells within a hard structure. Result is increased intracranial pressure leading to further brain injury Based on deteriorating clinical signs or highly suspect injuries Maintain adequate mean arterial blood pressure -- avoid hypertension Common treatment drug is mannitol +/- furosemide to extend duration of effect Mannitol & Head Trauma - Improves cerebral blood flow - Is an osmotic diuretic that occurs naturally as a sugar or sugar alcohol, in fruits & vegetables Osmotic diuretic (dehydrates brain) - Elevates blood plasma osmolality resulting in enhanced flow of water from tissues, including the brain and cerebrospinal fluid, into interstitial fluid and plasma therapy decreasing ICP - Increases intravascular volume & reduces blood viscosity - Contraindications -- dehydrated, hypovolemic, hypotensive, hypertonic saline would be more appropriate in these cases \% concentrations usually 25% Keep in medical warmer to prevent crystals -- if not available roll & warm in hands Use filter needed and or filters in IV lines to catch crystals **Head Trauma & Nursing Essentials** Place head and forebody on board at a 30 degree angle -- helps venous blood drain from brain Avoid jugular compression +/- pain control & sedation **Peripheral Nervous System Emergencies** - Present with weakness - Life threatening if resp muscles become paralyzed - Acquired myasthenia gravis: result of antibodies generated against the acetylcholine receptors on the muscles surface at the neuromuscular junction - Focal - Generalized - Fulminant (abrupt severe onset) - Polyradiculoneuritis (coonhound paralysis) an autoimmune disorder, may also be seen in both dogs & cats - Tick paralysis -- is more commonly seen in dogs - Botulism -- rapidly ascending motor paralysis in dogs resulting from ingestion of botulinum toxin produced by Clostridium botulinum Treatment - First concern is resp ability - Patients with megaesophagus should be fed upright - No specific treatment requirements beyond supportive nursing care **Vestibular Disorders** - Often present as emergencies because of alarming clinical signs - Rarely life threatening - Idiopathic old dog vestibular syndrome -- most common - Feline idiopathic vestibular syndrome - Otitis media/interna - Horner's syndrome Treatment - Emergency treatment may require to treat dehydration - Comfort & padding for ataxia, falling, bumping - May be circling a lot -- IVF if not indicated IVC may be better off with PRN vs IFV - Treat nausea, anxiety