Blast Injuries and Trauma Resuscitation

What is the goal of hemostatic resuscitation with blood components?

Maintain circulating volume Limit ongoing bleeding Prevent the lethal triad of hypothermia, acidosis and acute coagulopathy of trauma

What would you suspect in a pt with an intestinal blast injury who was hemodynamically unstable?

Mesenteric hemorrhage or solid organ injury

_______________________________________ is likely beneficial in the early stages of resuscitation, particularly for penetrating trauma

Permissive hypotension

The maximum amplitude of a TEG is determined by the ___________________________ and is corrected with ________________________.

Platelets Platelets

If platelets are less than 80, what should be given?

Platelets (duh) Note: Should also be given if there is platelet dysfunction

What are some radiographic signs of intestinal blast injury?

Pneumoperitoneum Free intraperitoneal fluid no consistent with blood Sentinel clot seen adjacent to bowel wall or mesentery

This is defined as an injury due solely to the blast wave

Primary blast injuries

What are the signs and symptoms of a pulmonary blast injury?

Tachypnea Dyspnea Cyanosis Hemoptysis Diminished breath sounds Crepitus from SubQ air O2 sat below 90% on room air (hypoxia)

This is defined as the result of displacement of the victim or environmental structures, is largely blunt traumatic injuries

Tertiary blast or explosive injury

This is a point of care test that measures clot strength and shows the interaction of platelets with the coagulation cascade (aggregation, clot strengthening, fibrin cross linking, and fibrinolysis)

Thromboelastogram (TEG)

Why would a TEG be performed?

To guide fluid/blood resuscitation Note: Does not necessarily correlate with blood tests such as INR, aPTT and platelet count (which are often poorer predictors of bleeding and thrombosis)

Excessive crystalloid administration is associated with _______________________, _______________________, and ______________ in bleeding patients

hypothermia coagulopathy death

For traumatic amputations clinicians should have a high clinical suspicion for occult explosive injuries to the ______________, _______________, and ______________________________ and should search for them in the patient who does not respond appropriately to resuscitation once control of extremity hemorrhage is achieved.

CNS, thorax, abdomen

___________ scan should be used to search for evidence of blunt head injury and ICH.

CT

Hypotension following a cardiovascular blast injury has been associated with low _______________________ and _______________________ but normal _________________________________.

Cardiac index and stroke volume; normal systemic vascular resistance

How should you manage a trauma patient with a MAP of > 65?

Check perfusion (radial pulse and pulseox waveform) If you have bad perfusion you can give fentanyl BP should

The presence of _________________________ and _________________________ together, this can be a valuable triage tool to alert the provider to keep a patient for further observation

oral petechiae and perforated tympanic membrane

Describe why Acidosis is part of the lethal triad.

pH strongly effects activity of Factors V, VIIa and X. Acidosis inhibits thrombin generation. Cardiovascular effects of acidosis (pH <7.2) - decreased contractility and CO, vasodilation and hypotension, bradycardia and increased dysrhythmias

Physical exam of a pt with a traumatic brain injury should include a thorough neuro exam to include checking for positive _______________________________ as well as __________________________ to look for evidence of air emboli

Romberg's sign Fundoscopy

What are some of the early signs of severe primary blast injury?

Ruptured tympanic membrane Ossicular disruption Alveolar hemorrhage Cerebral, coronary, retinal and lingual air emboli Ruptured viscus with Pneumoperitoneum and vagally mediated bradycardia Apnea Hypotension

This is defined as primarily ballistic trauma resulting from fragmentation wounds from the explosive device or the environment

Secondary blast or explosive injury

What are the three steps of damage control resuscitation?

1) Permissive Hypotension (aka minimal normotension) (this is controversial) 2) Early hemostatic resuscitation 3) Damage control surgery Note: You want to maintain circulating volume, control hemorrhage and correct the 'lethal triad' of coagulopathy, acidosis and hypothermia

A fibrinogen of less than ___________ identifies a hypofibrinogenemic state, the antidote for which is cryoprecipitate

1.0 g/L

How are blood products typically given?

1:1:1 Based on the rational that it mimics the composition of whole blood - PRBCs, FFP, platelets PROPPR Trial found an absolute difference in mortality of about 4% favoring the 1:1:1 ratio as opposed to the 2:1:1 ratio

TXA must be given in under _______ hours

3

In most circumstances a MAP of ______ shold be our aim. There is no benefit of going above this.

65

Patients with severe head and spinal injury are probably an exception to permissive hypotension; in such cases a MAP of __________________ has been recommended to promote cerebral perfusion

>80 mmHg

What kind of symptoms may be present in a pt with intestinal blast injury?

Abdominal pain, nausea, vomiting, hematemesis, melena, peritoneal signs of injury

1 in 4 trauma patients bleed abnormally. The phenomenon of an early coagulopathy in trauma (many names) but sometimes called __________________________________ can occur soon after injury and is physiologically distinct from the DIC-like phenomenon associated with the lethal triad

Acute Coagulopathy of Trauma-Shock

______________________may be a useful adjunct in patients with blast-induced bradycardia who do not respond as predicted to resuscitation efforts.

Atropine

How should a pulmonary blast injury be managed?

Avoid positive pressure ventilation Minimize positive end expiratory pressure ventilation Use judicious fluid resuscitation strategies

What is the most common radiographic finding in patients with blast lung injury?

Bilateral central lung infiltrates "batwing" sign

__________________________ is the most common fatal injury

Blast lung injury

Describe the pathophysiology of the blast injury

Blast waves enter the body creating two types of energy (1) Stress waves (2) Shear waves Stress waves: Longitudinal pressure forces that move at supersonic speeds and create a "spalling" effect at air-tissue interfaces, much like boiling water, resulting in severe microvascular damage and tissue disruption Shear waves: Transverse waves that cause asynchronous movement of tissue and possible disruption of attachments

What is the triad of symptoms associated with cardiovascular blast injury?

Bradycardia Hypotension Apnea Note: This is a partially mediated response to thoracic blast

What are the most common blast induced arrhythmias?

Bradycardia, PVCs, Asystole

The reaction time of a TEG is determined by the ___________________________ and is corrected with ________________________.

Clotting factors; FFP

What are some of the opthalmic physical exam findings that you might expect to find in a pt with a blast injury?

Conjunctival hemorrhage Diminished visual acuity Hyphema Globe rupture Presence of foreign body Lid lacerations

The speed of fibrin cross linking in a TEG is corrected with ________________________.

Cryoprecipitate

Why are crystalloid fluids of decreased benefit in the trauma patient?

Crystalloids have no O2 carrying capacity and do little to correct the anaerobic metabolism and O2 debt associated with shock.

Describe why hypothermia is part of the lethal triad.

Decreases platelet responsiveness, increases platelet sequestration in liver and spleen, reduces Factor function (factors XI and XII). Alters fibrinolysis

Which organs are most likely to be affected by a primary blast?

Ears Lungs Colon or gas filled organs with the damage originating at the tissue-gas interface

Describe some of the psychological symptoms associated with a traumatic brain injury.

Excitability Irrationality Retrograde amnesia Apathy Lethargy Poor concentration Insomnia Psychomotor agitation Depression Anxiety

What are the components of patient risk stratification? (what do you want to know about the incident and the patient)

Explosive device details: type and weight of explosive, improvised vs. commercially available, suicide bomber, time of detonation Geography: device location, open vs. closed space detonation, surrounding structures (urban vs. rural setting) Victim: distance of the victim from the detonation center, specific location of the victim with orientation of body in relation to explosive and surrounding structures, personal protective equipment Status of other casualties: cause of any on-scene deaths, primary blast injury in other surviving victims

What should be given if there is an INR of >1.5?

FFP

Describe some of the physical symptoms associated with traumatic brain injury.

Fatigue HA Back pain/diffuse pain Vertigo Transient paralysis "Heavy" extremities

___________________________is the primary substrate for clot formation (along with platelets)

Fibrinogen Note: There is a consistent link between falling fibrinogen and mortality in trauma

The time to reach fixed strength in a TEG is determined by the ___________________________ and is corrected with ________________________.

Fibrinogen; Cryoprecipitate

How should you manage a trauma patient with a MAP of < 65?

Give fluids and blood products

What are the most common symptoms of auditory injury?

Hearing loss Tinnitus Pain Dizziness

What conditions may result from a pulmonary blast injury?

Parenchymal hemorrhage Pulmonary edema Pneumothorax Air embolism Alveolovenous fistulas

__________________________________________ are a safe and reasonable option for the hypotensive, head injured patient, although there is no conclusive evidence of their benefit.

Hypertonic saline

What is the single best predictor of outcome in the trauma patient? Why?

INR It encompasses the two reasons these patients die: 1) In brain injury you release tissue thromboplastin you therefore use all your factor seven and your INR goes up. 2)Hemorrhage causing coagulopathy.

What is considered a good urine output in the trauma patient?

If your patient if making >50mls an hour you're probably doing ok > 0.5 mL/kg/hour

Why has pressure-limited, volume controlled ventilation with permissive hypercapnia been advocated in patients with pulmonary blast injury?

In order to minimize mean airway pressure and the chance of air embolism as well as to reduce the risk of further pulmonary trauma Note: When all else fails, the provider may resort to salvage methods like ECMO.

How do you monitor progress in the trauma patient?

Lactate and Base excess - both are closely related to shock and volume loss They reflect metabolic derangements and tissue level

How should massive hemorrhage or obvious hollow viscus perforation be treated?

Laparotomy for hemostasis and control of spillage of enteric contents

How would you manage a patient with mesenteric or mural hematoma in hemodynamically stable patients?

NPO NG tube decompression Resuscitation

What should be given if there is an active bleed?

PRBCs

What are the symptoms of ocular injury from a blast?

Pain Irritation Altered vision Periorbital swelling Contusion Foreign body sensation in the case of injury

These are defined as burns, toxins, and radiologic contamination

Quaternary explosive injuries

What are the things that TEG evaluates?

R - reaction time; time to first clot formation K - time to reach fixed strength (20mm) Alpha Angle - speed of fibrin cross linking MA (Max Amplitude) - overally stability determined by platelets LY30 - amplitude at 30 minutes post-MA and gives measure of degree of fibrinolysis

Clinical diagnosis of blast lung injury is based on the presence of what characteristics?

Respiratory distress Hypoxia Butterfly or batwing infiltrates

This is an antifibrinolytic agent that can/should be used early in the resuscitation of bleeding trauma patients

Tranexamic Acid

Statistically speaking, if you are going to die from an injury, it will be due to a severe _______________________________________.

Traumatic brain injury Note: Close behind that is death from exsanguination

_______________________________ is the most common primary blast injury

Tympanic membrane rupture

The LY30 of a TEG can be corrected with ________________________.

antifibrinolytics such as TXA

If calcium is less than .8, what should be given?

calcium gluconate

Provider should be aware that hemorrhaging explosion-injured patients may not have the expected __________________________________________ and may become hypotensive without rapid resuscitation

compensatory tachycardia

Large volume crystalloids can lead to _____________________________________ and exacerbate bleeding.

dilutional coagulopathy