Trauma and Orthopedic Surgery: PART I

Question 1

Primary survey

Answer 1

the assessment of trauma patients begins with a primary survey in which life-threatening conditions are identified and treated using the sequential ABCDE approach.

Question 2

What does ABCDE stand for in the ATLS approach to trauma?

Answer 2

Airway (check if airway is patent by asking patient to speak and inspecting mouth/larynx), Breathing (measure pulse oximetry and inspect/auscultate the chest wall), Circulation (palpate pulses and measure blood pressure), Disability (assess GCS score and pupillary size), and Exposure (undress the patient and examine for occult injury; palpate for vertebral tenderness and rectal tone).

Question 3

When are the secondary and third surveys performed?

Answer 3

After the patient is stabilized, the secondary survey is performed, which involves a thorough history and physical examination as well as diagnostic testing to identify other injuries. The tertiary survey is performed within 24 hours of presentation to identify missed injuries.

Question 4

In the primary survey, when would be appropriate to intubate someone?

Answer 4

Airway obstruction and/or respiratory failure

Depressed mental status (e.g., GCS ≤ 8)

At-risk inhalation injury

Question 5

____________ is a life-threatening circulatory disorder that leads to tissue hypoxia and a disturbance in microcirculation.

Answer 5

Shock (circulatory shock): a life-threatening disorder of the circulatory system that results in inadequate organ perfusion and tissue hypoxia, leading to metabolic disturbances and, ultimately, irreversible organ damage.

Question 6

What are the diferent kinds of shock?

Answer 6

The numerous causes of shock are classified into hypovolemic shock (e.g., following massive blood/fluid loss), cardiogenic shock (e.g., as a result of acute heart failure), obstructive shock (e.g., due to cardiac tamponade), and distributive shock (due to redistribution of body fluids), which is further classified into septic, anaphylactic, and neurogenic shock.

Question 7

What is the nexus criteria?

Answer 7

NEXUS criteria, which state that the absence of all of the following indicates a low risk for cervical spine injury and no need for imaging:
Focal neurological deficit
Posterior midline cervical spine tenderness
Altered consciousness
Intoxication
Painful distracting injury

Question 8

When is a cervical collar warranted?

Answer 8

In patients with blunt trauma to the head and neck, a cervical spine injury should be assumed until proven otherwise. The fact that this patient does not respond verbally to questions despite being conscious raises concern that his airway is compromised. This patient needs a cervical collar to immobilize the cervical spine, ensuring protection of his airway from further damage. This step addresses part “A” (airway assessment and protection) of the ABCDE approach to managing trauma patients.

Question 9

Endotracheal intubation is indicated for patients with a GCS of what?

Answer 9

8 or less

Question 10

How do you calculate a GCS?

Answer 10

A standardized scale used to assess level of consciousness and neurological status.

EYES, VERBAL, MOTOR:

Question 11

When do you use a tracheostomy vs cricothyrotomy?

Answer 11

Tracheostomy is a relatively lengthy procedure used in patients who have been intubated for 1–3 weeks and still require prolonged mechanical ventilation, as it improves patient comfort and decreases the work of breathing. It may also reduce the risk of respiratory infection compared to endotracheal intubation.
Cricothyrotomy is the down and dirty version.

Question 12

When is a CT scan of the spine warranted?

Answer 12

A CT scan of the spine to rule out spinal injury is indicated for a patient with any of the following: high-energy trauma, distracting injury, intoxication, focal neurological deficit, altered mental status, or spinal tenderness. A fall from a height ≥ 3 m (10 ft) is an example of high-energy trauma .

Question 13

Signs of spinal shock

Answer 13

flaccid, areflexic paralysis, anesthesia below the level of the injury

Question 14

Signs of neurogenic shock

Answer 14

bradycardia, hypotension, vasodilatation

Remember there is loss of sympathetic tone

Question 15

Emergent rapid fluid replacement in a child who you cant get IV access on, you should do….

Answer 15

IO line into the proximal tibia

Question 16

What are decortication and decerebration?

Answer 16

Question 17

What are the kinds of distributive shock?

Answer 17

septic, anaphylactic, and neurogenic

Question 18

What criteria do we use to define sepsis/septic shock?

Answer 18

SIRs Criteria

Question 19

What is the SIRs criteria?

Answer 19

Temp over 38 or under 36
HR over 90
RR over 20 or PaCO2 less than 32
WBC greater than 12,000, less than 4000 or greater than 10% bands

This criteria is used to define the severity of sepsis/ septic shock

Question 20

Which shock has decreased SVR/afterload?

Answer 20

Distributive shock

Question 21

What are some causes of cardiogenic shock?

Answer 21

MI, arrythmias, valvulopathy, cardiotoxic substance, cardiomyopathy, blunt cardiac trauma, myocarditis

Question 22

What are some causes of obstructive shock?

Answer 22

cardiac tamponade and tension pneumo

Massive PE, aoritc dissection, aortic stenosis, constrictive pericarditis, restrictive cardiomyopathy

Question 23

What are some causes of hypovolemic shock?

Answer 23

hemorhage, GI bleed, fluid from skin, kidneys, third spacing.

Question 24

For a pt who was rescued from a fire, what airway complication must you anticipate?

Answer 24

Inhalation injury leading to airway compromise

Question 25

Why do we intubate a patient under general anesthesia?

Answer 25

Airway protection

Question 26

Describe the pathophys behind hypovolemic shock

Answer 26

Loss of intravascular fluid volume → ↓ preload and SV → ↓ CO → compensatory ↑ SVR and HR

Question 27

Describe the pathophys of cardiogenic shock

Answer 27

↓ CO and ↓ BP → ↑ catecholamines → vasoconstriction and ↑ myocardial oxygen demand → ↑ renin-angiotensin-aldosterone system → further ↑ vasoconstriction and retention of sodium and water → shunting of blood to the brain and vital organs → insufficient perfusion of peripheral organs

Question 28

Why must we be careful with fluids in the case of cardiogenic shock?

Answer 28

Fluids can worsen the situation!!

IV fluids can worsen cardiogenic pulmonary edema in most cases of cardiogenic shock.

Question 29

What is the pathophysiology behind obstructive shock?

Answer 29

obstruction of the heart or its great vessels → inability of the heart to circulate blood → ↓ CO → compensatory ↑ SVR

Question 30

Describe the pathophys of neurogenic shock

Answer 30

Specific mechanism: damage of autonomic pathways → loss of sympathetic vascular tone → unopposed vagal tone → peripheral vasodilation → pooling of peripheral blood

Question 31

Describe the pathophys behind septic shock

Answer 31

Dysregulated host response to infection → capillary leakage and systemic vasodilation → acute organ dysfunction

Question 32

Describe the mechanism behind anaphylactic shock

Answer 32

immunologic anaphylaxis (type I hypersensitivity reaction; IgE-mediated) or nonimmunologic anaphylaxis (not IgE-mediated) → degranulation of mast cells → massive histamine release → systemic vasodilation and increased capillary leakage

Question 33

What type of contents get released in rhabomyolysis and crush injuries?

Answer 33

Intracellular contents such as myoglobin, potassium, phosphate, creatine phosphokinase (CPK), and urate, into the blood and extracellular space.

Question 34

What does the release of Creatine phosphokinase and serum myoglobin lead to in the setting of rhabdomyolysis?

Answer 34

Creatine phosphokinase (CPK) and serum myoglobin → pigment nephropathy → acute tubular necrosis → acute kidney injury (intrinsic)

Question 35

What does the release of potassium lead to in the setting of rhabdomyolysis?

Answer 35

Potassium → cardiac arrhythmia

Question 36

What does the release of lactic acid lead to in the setting of rhabdomyolysis?

Answer 36

Lactic acid → metabolic acidosis

Question 37

How does acute kidney injury come about in rhabdomyolysis?

Answer 37

Two ways really;

Creatine phosphokinase (CPK) and serum myoglobin → pigment nephropathy → acute tubular necrosis → acute kidney injury (intrinsic)

Hypovolemia → ↓ renal perfusion → acute kidney injury (prerenal)

Question 38

What labs would you look out for in a pt with rhabdo/crush injury?

Answer 38

↑ CPK
CMP
↑ BUN, ↑ Creatinine
anion gap metabolic acidosis

Question 39

What is a big complication with reperfusion in a rhabo or crush injury patient?

Answer 39

Compartment syndrome is a big one
“Reperfusion syndrome → compartment syndrome”

A condition characterized by endothelial damage caused by a returning blood supply after a period of ischemia (e.g., myocardial infarction, ischemic stroke). Causes increased capillary permeability, tissue swelling, and release of reactive oxygen species. Extensive reperfusion injury (reperfusion syndrome) is associated with systemic disturbances such as acidemia, hyperkalemia (which can cause cardiac arrhythmias), and edema (which can cause compartment syndrome).

Question 40

Which posturing (decorticate or decerebrate) is associated with a better prognosis?

Answer 40

Decorticate posturing is associated with a better prognosis than decerebrate posturing

Question 41

What is the cushing reflex?

Answer 41

A hypothalamic response to maintain cerebral perfusion in patients with elevated ICP. Results in the Cushing triad, which consists of increased systolic blood pressure, bradycardia, and irregular breathing

Question 42

What is cushings triad?

Answer 42

Cushing triad, increased systolic blood pressure, bradycardia, and irregular breathing

Question 43

What is the monro-kellie principle?

Answer 43

The sum of volumes of intracranial blood, CSF, and brain within the cranium is constant, which means that an increase in one component volume will be compensated for by a decrease in other(s).

Question 44

What is the pathophys behind cushings reflex?

Answer 44

↑ ICP → ↓ CPP → compensatory activation of the sympathetic nervous system → ↑ systolic blood pressure → stimulation of aortic arch baroreceptors → activation of the parasympathetic nervous system (vagus) → bradycardia

↑ Pressure on brainstem → dysfunction of respiratory center → irregular breathing

Question 45

How do we calculate cerebral perfusion pressure?

Answer 45

Cerebral perfusion pressure (CPP): the effective pressure that delivers blood to the brain and is responsible for constant perfusion of brain tissue

CPP = MAP - ICP

Question 46

What physiologic parameters have major influence on CPP?

Answer 46

Cerebral perfusion is predominantly modulated by the partial pressure of carbon dioxide (pCO2).

CPP linearly increases with pCO2 until pCO2 > 90 mm Hg. [2]
Increased pCO2 → ↓ pH → vasodilation → ↑ cerebral blood flow to remove excess CO2
Decreased pCO2 → vasoconstriction → ↓ cerebral blood flow

Cerebral perfusion is, to a lesser degree, modulated by brain temperature through cerebral metabolism. [5]
Hyperthermia → ↑ cerebral metabolism → ↑ CBF → ↑ cerebral blood volume → ↑ ICP
Mild hypothermia → ↓ cerebral metabolism → ↓ CBF → ↓ cerebral blood volume → ↓ ICP

Question 47

What is therapeutic hyperventilation and how does it work?

Answer 47

Therapeutic hyperventialtion is when we decrease pCO2 when cerebral edema is not responsive to other treatments.

Therapeutic hyperventilation reduces pCO2 → ↓ cerebral blood flow → ↓ intracranial pressure (used, e.g., when patients with acute cerebral edema are unresponsive to other treatments).

Less CO2 meains the body will reflexively decreased cerebral perfusion pressure

Question 48

Spinal shock typically resolves within

Answer 48

48 hours

Question 49

first-line diagnostic test in patients with traumatic cervical myelopathy

Answer 49

MRI w/o contrast

Question 50

most commonly occurs in older individuals with cervical spondylosis after acute hyperextension following a trauma like following a fall

Answer 50

Central cord syndrome

Question 51

In a pt with phabdo, when is compartment syndrome most likely to occur?

Answer 51

After fluid rescuscitation

Question 52

Summarize what is transmitted in the dorsal columns and the spinothalamic tracts

Answer 52

The dorsal columns, which are located posteromedially within the spinal cord, transmit ipsilateral proprioceptive, vibratory, and some light-touch sensations, while the anterolateral spinothalamic tracts transmit contralateral pain and temperature sensations. The posterolateral corticospinal tracts transmit ipsilateral motor impulses.

Question 53

Calculate their GCS: He does not respond to any commands but does groan. Painful stimuli cause him to open his eyes and withdraw all extremities.

Answer 53

This patient has a Glasgow Coma Scale (GCS) of 8 (groans = 2; opens eyes to pain = 2; withdraws extremities to pain = 4).

Question 54

How do we help post operative acute respiratory distress syndrome in pts who are already intubated and ventilated?

Answer 54

Increasing positive end-expiratory pressure (PEEP) helps to expand collapsed alveoli and decreases fluid within the alveoli in a patient with pulmonary edema, as seen in pts with ARDS.

Question 55

In a little old lady who fell and broke her hip, what kinds of complications/shock might you look out for?

Answer 55

Little old lady, if she is on eliquis or another kind of blood thingger, then we want to worry about bleeding. Hypovolemic shock would be one to watch out for and would present with diaphoresis, tachy, hypotension.

Another thing to keep in mind would be a pulmonary embolism from fat (a fat embolism in the setting of a long hip fracture). This would present with signs of obstructive shock including tachycarddia, dysnpnea, and signs of right ventricular overload like distended neck veins and ECG findings of right sided heart strain (right axis deviation, RBBB).

Question 56

Manifestations include periorbital ecchymosis with CSF rhinorrhea, CSF otorrhea, mastoid ecchymosis, and otorrhagia.

Answer 56

Basillar skull fracture

A skull fracture that involves at least one of the bones that make up the skull base. Manifestations include periorbital ecchymosis with CSF rhinorrhea, CSF otorrhea, mastoid ecchymosis, and otorrhagia.

Question 57

How are CO, pulmonary capillary wedge pressure, systemic vascular resistance, and central venous pressure impacted in hypovolemic shock?

Answer 57

↓ CO, ↓ PCWP, ↑ SVR, and ↓ CVP

–PCWP: Low right heart blood volume results in decreased blood delivery to the left atrium (shown by ↓ PCWP), low end diastolic volume leads to LOW CO and then low CO leads to hypotension, so the peripheral vasculature constricts (↑ SVR)

–CVP: hypovolemic shock. Hemorrhage (e.g., after sustaining a gunshot wound) leads to intravascular volume depletion, which decreases blood return to the right atrium (as evidenced by ↓ CVP)

Question 58

Pulmonary capillary wedge pressure can tell us what about volume status?

Answer 58

Pulmonary capillary wedge pressure indicates how much blood is getting delivery to the left atrium so low PCWP means low volume/blood delivery to left atrium

Question 59

Preferred imaging modality for assesment of the cervical spine

Answer 59

CT

Question 60

An x-ray of the ankle shows an extra-articular calcaneal fracture. Why would we get a spinal ct on this dude?

Answer 60

10–15% of calcaneal fractures are associated with another pathology due to the axial transmission of force.

Question 61

Sudden onset of paraparesis and autonomic dysfunction immediately after an aortic surgery, especially in the setting of intraoperative hypotension, is highly suggestive of _______________________

Answer 61

Sudden onset of paraparesis and autonomic dysfunction immediately after an aortic surgery, especially in the setting of intraoperative hypotension, is highly suggestive of anterior spinal artery (ASA) syndrome, as the artery that contributes to spinal cord perfusion (artery of Adamkiewicz) can be injured during aortic surgery.

Question 62

What are some causes of neurogenic shock?

Answer 62

Spinal cord injury (SCI)
Traumatic brain injury
Cerebral hemorrhage