Tuesday: 9/6/16 Surgery Exam 1 Flashcards
What is the pre-hospital management of a cervical spine trauma?
- Spinal immobilization
- Careful helmet removal
- Airway oxygenation
What is the ED management of cervical spine trauma?
- orotracheal intubation preferred unless significant facial trauma present
- Rapid-sequence intubation added for u scions patients who are breathing but need ventilatory support
- Inline cervical stabilization
- CT of entire cervical spine
- Monitoring for neurogenic shock from spinal cord injury
When is a laryngeal mask used?
Temporary measure to stabilize the patient until another airway can be established if orotracheal intubation fails
When is a nasotracheal intubation contraindicated?
- Apneic/hypopneic patients.
2. Basilar skull fractures because they are associated with cribriform plate disruption
Why is needle cricothryoidotomy not ideal in patients who might require hyperventilation to treat intracranial hypertension?
Risk of carbon dioxide retention
What can a cricothryoidotomy cause?
Tracheal stenosis
What is the pathophysiology of flail chest?
Caused by a blunt thoracic trauma and 3 or more ribs are fractured in 2 locations.
What are some findings in flail chest?
- Paradoxical chest wall motion with respiration.
2. Chest pain, tachypnea, rapid shallow breaths
What does a chest X-ray look like in flail chest?
Rib fractures +/- contusion/hemothorax
How do you manage flail chest?
- Pain control
- oxygen supplementation
- bilateral chest tubes if respiratory failure with positive pressure ventilation.
What causes respiratory failure in people with flail chest?
Pulmonary contusion and resultant collection of edema and blood in the alveoli
How does a diaphragmatic tear appear on X-ray?
As an abnormality in the diaphragmatic shadow, with herniation of abdominal contents into the left pleural space. The tip of the NG tube is typically seen in the left hemithorax rather than below the diaphragm
How does esophageal rupture appear on X-ray?
presents with subcutaneous crepitus and the X-ray has a pneumomediastinum.
What can lead to cardiogenic pulmonary edema?
Myocardial dysfunction may result from myocardial contusion and lead to pulmonary edema
How does pulmonary edema look on an Xray
bilateral alveolar infiltrates and interstitial markings would be expected on chest X-ray
How does tension pneumonthorax present?
- respiratory distress
- hypotension
- tachycardia
- tracheal and mediastinal displacement to the contralateral side
What is the pathogenesis of an epidural hematoma?
Trauma to sphenoid bone with tearing of middle meningeal artery
What are some clinical features of an epidural hematoma?
Brief loss of consciousness followed by luck interval
Hematoma expansion leads to decreased consciousness and increased intracranial pressure
How do you diagnose an epidural hematoma?
Head CT: Biconvex or lens shaped hyper density that does not cross suture lines
How do you treat an epidural hematoma?
Urgent surgical evacuation for symptomatic patients
What type of herniation can occur if an epidural hematoma goes untreated?
Uncal hernation
How does an uncal herniation present?
dilation of the pupil on the ipsilateral side of the lesion (due to oculomotor nerve compression) along with ipsilateral hemiparesis (due to contralateral crus cerebra compression)
When do you get a diffuse axonal injury?
traumatic acceleration/deceleration shearing forces that diffusely damage axons in the brain.
What does a head CT look like in diffuse axonal injury?
Diffuse small bleeds at the grey-white matter junction.
When does an acute subdural hematoma occur?
Traumatic shearing forces cause tearing of the bridging veins, leading to slow bleeding into the subdural space.
Who are more likely to get an acute subdural hematoma?
Patients with cerebral atrophy like the elderly or those with alcoholism.
What causes an increase in bleeding risk in someone who has had an SDH
The use of anticoagulants like warfarin
How does someone with an SDH normally appear
SDH usually develops gradually 1-2 days after the initial injury and often include impaired consciousness, confusion or symptoms of intracranial hypertension.
How does an SDH present on CT?
creascent shaped hyper density that crosses suture lines
How do cardioembolic strokes happen?
setting of a. fib. when a left atrial thrombus dislodges and occludes a cerebral artery.
Classic neuroimaging for cardioembolic strokes.
multiple lesions at the grey-white matter junction.
Pathogenesis of Normal pressure hydrocephalus.
decreased cerebrospinal fluid respiration by the arachnoid granulations
What are the neuroimaging findings for normal pressure hydrocephalus?
ventricular enlargement that is lout of proportion to sulci enlargement.
What is the pathogenesis of subarachnoid hemorrhage?
Typically occurs due to a ruptures saccular aneurysm and presents with thunderclap headache associated with brief loss of consciousness and meningismus.
How does the CT look for a subarachnoid hemorrhage
Shows acute hemorrhage between the arachnoid and the pia mater
How does an occipital ischemic stroke present?
Contralalteral homonomous hemianopia with macular sparing
What artery is thrombosed in an occipital ischemic stroke?
Posterior cerebral artery.
What does a meningioma originate from?
Arachnoid cap cells
On neuroimaging what does a meningioma look like
extra-axial, well circumscribed, dural based masses can be partially calcified.
If you have a lesion or a compression of the contralateral crus cerebra against the tenurial edge how does it present neurologically?
Ipsilateral hemiparesis
Neurologic signs of the compression of the ipsilateral oculomotor nerve by the herniated uncus.
- Loss of parasympathetic innervation causes mydriasis (early)
- Loss of motor innervation causes ptosis and a down and out gaze of the ipsilateral pupil due to unopposed troclear (CN IV) and abducent (CN VI) action (late)
Compression of the ipsilateral posterior cerebral artery
Contralateral homonymous hemianopsia
Compression of the reticular formation.
Altered level of consciousness; coma
Where is the uncus?
The innermost part of the temporal lobe and herniates through the tentorium to cause pressure on the ipsilateral oculomotor nerve, ipsilateral posterior cerebra artery and contra-lateral cerebral peduncle against the edge of the tentorium.
How does Abducens nerve injury present?
inability to abduct the eye and presents later in uncial herniation.
When do you have accessory nerve dysfunction?
Lesions in the medulla, such as occlusion of the posterior inferior cerebellar artery. or injured during surgical procedures involving the anterolateral neck.
How does accessory nerve injury present?
Paralysis of the ipsilateral sternocleidomastoid and trapezius muscles
Facial nerve injury presents in what way?
cause an upper motor neuron lesion, resulting in contralateral lower facial droop
How does a glossopharyngeal nerve injury present?
Loss of the gag reflex, loss of taste and sensation on the posterior one-third of the tongue, loss of pharyngeal sensation, dysfunction of the carotid sinus reflex leading to an increased risk of syncope
When do you see glossopharyngeal nerve injury?
Compression from a nearby tumor, as in jugular foramen syndrome or posterior fossa tumor.
How does transtentorial herniation present?
!. ipsilateral hemiparesis
- Ipsilateral mydriasis and strabismus
- Contralaleral hemianopsia
- Altered mentation.
When is it appropriate to assume there is aortic injury?
- decellaration injuries
2. Falls from more than 10 feet
What is the appropriate initial screening study of aortic injury?
Chest xray
What is the most sensitive finding of aortic injury on imaging?
Mediastinal widening
In what patient group do you see primary and secondary spontaneous pneumothorax?
Primary: no preceding event or lung disease; thin, young men
Secondary: Underlying lung disease like COPD
What are some signs and symptoms of spontaneous pneumothorax?
- chest pain, dyspnea
- Decreased breath sounds, decreased chest movement
- Ipsilateral HYPER-resonance to percussion
What do you see on imaging of a spontaneous pneumothorax?
Absent lung markings
Visceral pleural line
How do you manage a small and large spontaneous pneumothroax?
Small (
What are some associated features of a tension pneumothorax?
- LIFE THREATENING
2. often due to a trauma or mechanical ventilation
What are some unique signs of a tension pneumothroax?
Same as spontaneous PLUS
- HEMODYNAMICALLY instablie
- Tracheal deviation away from affected side
What are some imaging findings for tension pneumothorax?
Contralateral mediastinal shift
Ispilateral hemi-daphragm flattening
How do you treat a tension pneumothorax?
Urgent needle decompression or chest tube placement
Why do primary spontaneous pneumothroax occur?
Due to rupture of sub pleural blebs and commonly develops while patients are at rest.
When do you perform a needle decompression of a pneumothroax?
Stable patients with large ones, inserted in the second or third intercostal space in the mid-clavicular line or at the fifth intercostal space in the mid or anterior axillary
When do you do a tube thoracostomy in a patient with a pneumothorax?
Patients who are hemodynamically unstable should undergo emergent placement
What are some signs of increased intracranial pressure?
- headache
- nausea/vomiting
- altered mental status
When is cerebral angiography a useful diagnostic tool?
For identifying cerebral aneurysms and AV malformations
When are intravenous corticosteroids like dexamethasone indicated in patients with intracranial hypertension?
If it is due to brain tumor or abscess
What does intravenous mannitol do?
It is an osmotic diuretic that can reduce brain volume in patients with elevated intracranial pressure
How much can a hemothorax account for in terms of circulating blood volume?
Capable of holding up to 50% of the circulating blood volume and massive hemothoraxis defined as more than 1.5 L
What are some of the common causes of massive hemothorax?
Traumatic laceration of the lung parenchyma or damage to an intercostal or internal mammary artery
What is Hamman sign?
Audible crepitus on cardiac auscultation
How does a tracheobronchial tear appear?
- Dyspnea
- Hemoptysis
- Subcutaneous emphysema
- Hamman sign
- Sternal tenderness
Why is diaphragmatic future more common on the left side?
Because the right side tends to be protected by the liver.
How do you treat diaphragmatic tear?
Most patients require surgical repair and exploration of the abdomen for other traumatic injuries
What is a key Xray finding for someone with a diaphragmatic tear?
A nasogastric tube in the pulmonary cavity inidcating a need for surgical repair.
-referred pain to the shoulder
How would an aortic rupture present?
Normally dead/ If alive would be profoundly hypotensive and the chest X-ray would show widened mediastinum and be unstable hemodynamically
When do you see aortic injury?
Patients suffering from rapid deceleration blunt chest trauma.
What are some X-ray findings for aortic injury
- widened mediastinum
- large left-sided hemothorax
- Devaition of the mediastinum to the right and disruption of the normal aortic contour
How does esophageal rupture present?
- pneumomediastinum
2. pleural effusion
How is esophageal rupture diagnosed?
Water soluble contrast esophagography
How does myocardial contusion present?
- Tachycardia
- New bundle branch blocks or arrhythmia
- Sternal fracture
How does bronchial rupture present?
Pneumothorax that does not resolve with chest tube placement, pneumomediastinum and subcutaneous emphysema
