Trauma Anesthesia Flashcards
Statistics of trauma patients
- Trauma is the 3rd common cause of mortality
- 1/3 die within first 4 hours representing a majority of OR deaths
- Total annual cost of trauma is 1.8 billion per year
- Trauma represents 50% of all deaths in age groups 5-34 years old
What are the three sequential components of a trauma evaluation?
1) Rapid overview
2) Primary survey
3) Secondary survey
What is the rapid overview?
Very quick exam. Looking at the patient, do they look stable or unstable? Should only take a few seconds.
What is the primary survey?
A rapid evaluation of functions that are critical to survival.
Looks at ABCDE: Airway patency Breathing Circulation Disability Exposure
Details of ABCDE of the primary survey
1) Airway patency
2) Breathing
- Give high flow O2
- Keep trachea midline
- Is flail chest present? (if present, it means that 3 or more ribs have been fractured)
- Is massive hemothorax present? (>1500cc blood)
3) Circulation
- Skin temp and color
- 2 LARGE BORE IVs
4) Disability
- Neuro exam (GCS)
5) Exposure
- Final step of primary survey and includes complete exposure of the patient.
- Removal of clothing and turning to examine.
- Includes a brief head-to-toe search for all visible injuries or deformities
What is the secondary survey of the trauma evaluation?
A detailed and systemic evaluation of each anatomic region and continued resuscitation if needed. Begins after critical life saving actions have begun:
- Intubation, Chest tube placement, Fluid resuscitation
- The primary focus is: History of injury & Medical/Surgical History
Trauma airway evaluation
•Involves the diagnosis of trauma to the airway and surrounding tissue
•Anticipates the respiratory consequences
•Contemplate airway management maneuvers
•Most trauma patients require:
Assisted or controlled ventilation
oSelf-inflating bag with a non-rebreathing valve is sufficient after intubation and for transport.
o100%oxygen is necessary until ABG is complete
Airway obstruction considerations in the trauma patient
Cervical deformity Airway edema Dyspnea, hoarseness, stridor, dysphonia Subcutaneous emphysema & crepitation Hemoptysis Tracheal deviation Jugular vein distention Hemodynamic condition
Indications for intubation
Cardiac or respiratory arrest
Respiratory Insufficiency*
Airway protection
Need for deep sedation or analgesia
Transient hyperventilation
Delivery of 100% Fi02 in presence of carbon monoxide poisoning
Facilitate work-up in an un-cooperataive or intoxicated patient
Tracheostomy vs. cricothyroidotomy
Tracheotomy → takes longer to perform, requires neck extension which may cause extended neck trauma if cervical injury is present
Cricothyroidotomy → is contraindicated in those younger than 12 years old. Laryngeal damage precludes the ability to perform a cricothyroidotomy
- Massive facial trauma/ hemorrhage
- Supraglottic foreign body obstruction
- Angioneurotic edema
- Inhalational thermal injury
- Epiglottitis/ croup
Intubation considerations for trauma patients
- Full stomach is a consideration for ALL trauma patients and impacts AW intervention
- Time not available to allow pharmacologic intervention to decrease gastric contents and acidity
- Emphasis is placed on safe technique for securing the AW
- -> RSI with Cricoid pressure
- ->Manual inline stabilization
- -> Awake intubation with topical anesthesia (consider loss or protective reflexes) and sedation
- -> LMA use is CI as a definitive airway. Should only really be used as part of the difficult airway algorithm.
Airway considerations for head, open eye, and major vessel injuries
- Ensure adequate oxygenation and ventilation
- Deep anesthesia and profound relaxation prior to airway manipulation and intubation
- Without sufficient depth of anesthesia these patients may present with:
- -> Hypertension
- -> Coughing /bucking
- -> Increased ICP, IOP, and intravascular pressure
- Must consider the initial assessment of airway → if difficult you cannot use muscle relaxants or IV induction agents
Airway considerations for cervical spine injuries
- High suspicion for cervical injury if victim has experienced a fall, MVA & diving accident
- Semi-rigid collar, sandbags, and backboard provide best stabilization
- Manual inline stabilization (MIS) best for AW management
- Stabilization is maintained until cervical injury is ruled out
- Orotraheal intubation is most desirable
Airway considerations for maxillofacial injuries
- Blood and debris in the oropharyngeal cavity may predispose the patient to complete or partial AW obstruction
- Aspiration of teeth or foreign bodies
- Serious AW compromise may present within a few hours of penetrating facial trauma
- Consider limitation of mandibular movement and trismus
- AW management technique is based on the presenting condition
Airway considerations for cervical AIRWAY injuries
Results from either blunt or penetrating injury
Penetrating injury (depends on 3 interactive factors:
1) What instrument caused the wound
2) The velocity of the impact
3) Type of tissue it passed through.
- Clinically with penetrating injury, we’ll see escape of air, hemoptysis and coughing
Blunt Injury
- May be from direct impact, decelerating injury, shearing or rotary forces that cause laryngotracheal damage
- Clinically, will see hoarseness, muffled voice, dyspnea, stridor, dysphagia, cervical pain and tenderness, and flattening of the thyroid cartilage
Intubation in the case of cervical a/w injury should be done fiber optically
How does a tension pneumothorax usually develop and present?
Occurs from rib fractures and barotrauma from mechanical ventilation or d/t perforation during bronchoscopy
S/S include hypoTN, hypoxemia, tachycardia, increased CVP, and diminished breath sounds on the affected side
How does flail chest occur?
Fracture of 3 or more ribs, associated with costochondral separation and sternal fracture
Will see respiratory insufficiency and hypoxemia over several hours with deterioration of CXR and ABG
Consider pain management over mechanical ventilation in these patients
These are the hallmark symptoms of hemothorax
Hypotension, hypoxemia, tachycardia, and increased CVP. Basically the same shit as a tension pneuma, except the decreased breath sounds.
This is the most common cause of hypotension in trauma patients
Hemorrhage
What does the term “resuscitation” refer to?
The restoration of normal circulating blood volume, normal vascular tone, and normal tissue perfusion
What is the initial response to shock?
Comes from the neuroendocrine system
- Hypotension leads to vasoconstriction and catecholamine release
- Blood flow to heart, kidneys, and brain is preserved while other regional beds are constricted
What is the body’s physiologic response to chock?
- Initial neuroendocrine response
- Traumatic injuries lead to hormone release that set the stage for the microcirculatory response
- Ischemic cells respond by taking up interstitial fluid, thus depleting intravascular volume, and producing lactate and free radicals. Cellular swelling may also obstruct capillaries.
- Organ ischemia leads to anaerobic metabolism, producing lactic acid and acidosis
- Lactate and free radicals accumulate, causing direct damage to cells. Also, once circulation is re-established, there will be a mass release of these toxic substances from the tissues that were ischemic.
Specific organ responses to shock
Lungs- Inflammatory byproducts are in the bloodstream, and since the lungs receive 100% of the CO, they all pass through here, resulting in ARDS
GI System- One of the earliest organs affected by hypo-perfusion (d/t constriction of less important areas) and may be a trigger for the development of MOSF
CNS- Responsible for maintaining blood flow to brain, heart, and kidneys while shutting down flow to less important areas
Kidney/Adrenals- Maintains GFR during hypotension via vasoconstriction and concentrating blood flow in the medulla and deep cortical areas
Heart- Will receive an initial increase in nutrient blood flow and increase in function until later stages, where coronary perfusion can no longer be kept up
What does base deficit reflect?
- Severity of the shock
- O2 debt
- Changes in O2 delivery
- Adequacy of fluid resuscitation
- The likelihood of the development of multi-organ failure
Degrees of shock based on base deficit
Mild shock = 2-5mmol/L
Moderate shock = 6-14
Severe shock = >14
Patients who present with an admission base deficit of __-__mmol/L have increased mortality risk
5-8 (this falls into the moderate shock category of 6-14)
Which is a more specific indicator of shock: lactate or base deficit?
Base deficit
Normal blood lactate level is __-__mmol/L and the 1/2 life is ___
Normal is 0.5-1.5mmol/L
1/2 life is 3 hours
Plasma lactate > ___ indicates severe lactic acidosis
5
Failure to clear lactate within ___ hours after reversal of shock is a predictor of increased mortality
24 hours
Plasma lactate should return to normal within 24 hours after reversal of shock.
Sites for emergency IV access in order of desirability
1) Large bore IV in AC
2) Other large bore sites
3) Subclavian vein
4) Femoral vein
5) IJ
6) IO
Why is subclavian preferred to IJ in trauma?
Easier to place and does not require neck manipulation in the case of cervical neck injury or c-spine precautions
Goals for EARLY resuscitation
Maintain SBP 80-100 Hct 25-30% Maintain normal PT and PTT Plts > 50,000 Normal iCa Temp > 35C Maintain pulse-ox function (duh) Prevent increases in lactate Prevent worsening acidosis
Risks of aggressive volume replacement in early resuscitation
Increased BP, BUT Decreased blood viscosity Decreased Hct Decreased concentration of clotting factors Greater transfusion requirement Altered electrolyte balance Direct immune suppression Premature reperfusion
Algorithm for the management of EARLY hemorrhagic shock
If the patient is in shock and SBP is 30%, and keep PT
Goals for LATE resuscitation
- SBP > 100
- Keep Hct above the transfusion threshold for that individual patient
- Normalize coags
- Normalize electrolytes
- Normalize temp
- Normalize UO
- Maximize CO with the use of invasive and noninvasive monitoring
- Reverse acidosis
- Decrease lactate to normal range
Algorithm for the management of LATE hemorrhagic shock
1) Ask yourself, is the hemorrhage controlled and resuscitation complete? (Ex- SBP > 100, normal pH, lactate, and UO, HCT > 25, and PT
Overall management of shock
1) Control the source of the hemorrhage
2) Begin fluid resuscitation
3) What is a reasonable BP?
- 80-100 for early resuscitation
- > 100 for late resuscitation
Ratio of PRBC to FFP during massive transfusion
2 units of FFP for every 5 units of PRBCs.
The military replaces 1:1 RBC to FFP
What is the lethal triad?
Acidosis
Hypothermia
Coagulopathy
It is our goal in early management to avoid this lethal triad
Acidosis and hypothermia both lead to coagulopathy
Recognize that if you resuscitate with a shit ton of fluids without hemostasis properties can result in dilution of clotting factors and platelets
Reasons why hypothermia is bad:
- Acid/base imbalances are worsened
- Coagulopathies are worsened (impairs plt and clotting enzyme function)
- Myocardial function decreases
- O2-Hgb curve shifts to the left (decreased tissue oxygenation)
- Metabolism of lactate, citrate, and certain anesthetics are decreased
- Potassium and calcium levels become altered
- Causes vasoconstriction (can make BP look higher than it really is! The BP may drop as the patient is warmed)
Hypothermia has this effect on coagulation
Platelets are impaired and sequestered
Clotting enzyme functions decrease
At 29 degrees C, PT and PTT levels rise by ___% and Plts drop by ___%
PT and PTT increase by 50%
Plts decrease by 40%
Treatment of coagulopathy in trauma
AVOID THE LETHAL TRIAD
- -> Control hemorrhage, avoid and correct hypothermia, and actively rewarm - Practice judicious resuscitation --> we want to avoid hemodilution! - Treat coagulpathies - Remember that trauma disrupts the equilibrium between hemostatic and fibrinolytic processes - Changes are complex and you can experience both hypocoagulable or hypercoagulable states
Surgical Priorities in Trauma
1) Airway management (cricothyroidotomy if needed)
2) Control of hemorrhage causing exsanguination
3) Control of intracranial bleeds
4) Threatened limb or eyesight
GCS was originally introduced as a way to measure coma, but is used in trauma to
classify the severity of head injury
Classification of TBIs
Mild
- GCS 13-15
- Usually managed by getting a CT and observing for a short period of time
Moderate
- GCS 9-12
- Early CT needed
- Usually involved intracranial bleeds that require evacuation
- High potential that the pt may deteriorate and require intubation
Severe
- GCS
Severe TBI management
SBP > 110 and MAP > 90 (corellates to CPP of 70)
- Maintain CPP of > 70 at all times
- Maintain euvolemia
- Correct anemia (Hct > 30 to maintain O2 delivery)
- Control ICP with IVC
- Correct pt positioning
- Judicious use of narcotics (need to maintain near exam)
- Mannitol therapy
- Hypertonic saline (HTS)
Vent management in severe TBI
- Maintain PaCO2 30-35 for high ICP
- Hyperventilate to PaCO2 of 30 if ICP is not lowering in response to sedatives, CSF drainage, NM blockade, osmotic agents (mannitol and HTS), or barbiturate coma
- Hyperventilation is used ONLY if herniation is imminent. Remember that this is a short term therapy, and the body will only respond to this for about 6 hours or so.
Airway management in head trauma
Basically, we want to control their airway and avoid increases in ICP
- Intubate to control O2 and CO2 levels
- Judicious use of induction agents –> generally want them deep enough so that they don’t response to DVL
- Paralyze them to avoid coughing and bucking
If using sux, consider pretreating with NDMR
General anesthetic goals in head trauma
- Any of the 3 gases is fine, but avoid N2O
- Avoid ICP > 20
- Avoid hypotension
- Make sure you have an a-line
Where do most spinal cord injuries (SCIs) occur?
Low cervical spine (C7 most common)
The outcome of SCI patients depends on these 3 factors
1) Severity of the injury
2) Prevention of exacerbating injury during rescue, transport, and hospitalization
3) Avoiding hypotension and hypoxia
What does early treatment of SCI focus on?
Maintaining cord perfusion to avoid secondary injury
Autonomic hyperreflexia develops in __% of SCI patients with complete injury above ___
85% of complete injuries above T5
Management of SCI
- Aimed at maintaining perfusion (avoid hypotension!)
- Avoid hypoxemia and hypercarbia, and both of these can exacerbate injury
- MAP normal to high normal
- Neurogenic shock may occur
- Ensure circulation is adequate
- Bolus of glucocorticoids (remember we did the solumedrol protocol in my emergency c-spine case)
- The entire c-spine should be evaluated (C-7 is the most common site of injury)
Intubation in SCI
- Emergency intubation (need to maintain oxygenation to the cord and prevent hypercarbia. Even more important in c-spine injury because neck damage may result in tracheal compression and there is less collateral flow in the cervical area compared to the rest of the cord)
- BEST technique by the book is awake fiberoptic
- Use techniques that the provider is most familiar with so that intubation can be completed in the least amount of time and with minimal manipulation
- Avoid any movement of the neck during DVL. Should be performed with manual inline stabilization (MIS)
- Sux can be used if
When can sux be used
If less than 24 hours after spinal cord injury
Anesthesia for orthopedic and soft-tissue trauma
- Patient may have multiple broken bones, crush injury, open fractures, compartment syndrome, dislocations, etc.
- Pts are at high risk for developing DVT
- Usually require GA
- Normal anesthetic requirements, but may have lower requirements if the pt is hypovolemic.
- Surgeon may ask for controlled hypotension (MAP 20mmHg below baseline) as long as there are no contraindications
- Allow spot breathing at end of case to guide narcotic dosing
- Consider TEE
Advantages and disadvantages of RA in trauma
Advantages
1) Allows for continuous assessment of mental status
2) Increased vascular flow
3) Avoidance of airway instrumentation
4) Improved mental status post-op (b/c they’re not all drugged up)
5) Decreased blood loss
6) Less incidence of DVT
7) Better pulmonary toilet
8) Earlier mobilization
9) Improved analgesia
Disadvantages
1) Difficult to assess peripheral nerve function
2) Pts often refuse
3) Requires sedation
4) Takes longer to achieve anesthesia compared to GA (need time to place the block, for it to set in, and to provide sedations, etc)
5) Not suitable for situations involving multiple body regions
6) Often difficult to judge the length of trauma surgeries
Advantages and disadvantages of GA in trauma
Advantages
1) Fast onset and case start
2) Duration can be maintained as long as needed
3) Can be used when treating multiple body sites
4) Greater patient acceptance
5) Allows for PPV
Disadvantages
1) Can’t assess mental status
2) Requires airway instrumentation
3) More complex hemodynamic changes
4) Potential for barotrauma and DVT
Pulmonary injuries
Chest tube
Thoracotomy
- indicated if chest tube drainage is more than 1500 in the first several hours, when tracheal injury, bronchial injury, or massive air leak are noted, or if there is hemodynamic instability from thoracic injury. Gotta see what shit is going on inside!
- Intubation with RSI, double lumen tube. Often there will be two intubations. First single lumen tube to do a bronchoscopy, and intubate again with a DLT.
Traumatic aorta injury
- High M&M
- Always suspect possibility of aortic injury in high energy injury like MVA or fall
- Diagnosis is from CXR, angio, CT, and TEE
- If damage present, immediate surgery is done d/t high rupture risk in the first hours to days after injury
- Patient will be on bypass to bypass damaged aorta
Rib fracture
Remember flail chest means 3 or more ribs have been fractured
In flail chest, consider pain management and/or epidural to maintain ventilation. Ventilation will be very painful in those with rib fracture!
Cardiac Injury
- Penetrating cardiac injury rarely has high pre-hospital mortality
- Cardiac bruising/contusion is functionally indistinguishable from MI
- Cardiac tamponade may be present!!
- Manage cardiac injury as MI –> be careful with fluid volume, vasodilators, monitor and treat dysrhythmia
- Cardiology consult if appropriate
Special considerations for Jehovah’s witnesses, elderly, and pregnant ladies
Jehovah’s Witness
- Deliberate hypotension
- Use salvaged blood
- Early hemodynamic monitoring
- Post-op EPO
Elderly
- Elderly have worse outcomes in trauma
- Decreased CP reserve and higher incidence of post-op ventilation
- MOSF after hemorrhage shock
- Post-traumatic myocardial dysfunction
Pregnancy
- High incidence of going into preterm labor or having a spontaneous abortion
- Consult OB!!
- Need rapid resuscitation of the mother (remember that the placenta does not auto regulate and blood flow to the fetus is dependent on maternal BP!)
Criteria for extubation after trauma
1) Mental Status
- Any intoxication is resolved
- Pt is following commands
- Pt is not combative
- Pain is controlled
2) Airway anatomy and reflexes
- Pt is able to protect their own airway
- Cough and gag reflexes present
- No excessive airway edema
3) Respiratory mechanics
- Pt ventilating well with good volumes and rate
- Required FiO2 is less than 50%
4) Systemic stability
- Pt is adequately resuscitated and no signs of sepsis
- Low risk of returning to the OR (otherwise leave intubated to avoid intubating a second time)
Risk factors for ARDS after trauma
- Elderly
- Pre-existing physiologic impairment
- Direct injury to lung or chest wall
- Aspiration of blood or stomach contents
- Prolonged mechanical ventilation
- Severe TBI
- Spinal cord injury resulting in quadriplegia
- Hemorrhagic shock
- Massive transfusion
- Occult hypoperfusion
- Wound or body cavity infection
Recommended vent settings in trauma
TV 6-8mL/kg
PEEP 10-15
Limit PIP to
Post-op complication concerns
Infection/sepsis
Thromboelmbolism
Abdominal compartment syndrome
ARDS
