View source for Traumatic cardiac arrest

{{Infobox medical condition (new)
| name          = 
| synonym       = 
| image         = Human heart male adult autopsy.jpg
| image_size    = 250px
| alt           = 
| caption       = Human heart from an autopsy
| pronounce     = 
| specialty     = Cardiology, Emergency Medicine, Critical Care, Trauma
| symptoms      = 
| complications = 
| onset         = Acute onset following trauma to the chest
| duration      = 
| types         = 
| causes        = Blunt or penetrating trauma to the chest
| risks         = 
| diagnosis     = ECG, chest x-ray, bedside echocardiogram
| differential  = Hemorrhagic shock, tension pneumothorax, hemothorax, cardiac tamponade, hypoxia
| prevention    = 
| treatment     = Thoracotomy, thoracostomy, fluid resuscitation, decompression, pericardiocentesis
| medication    = 
| prognosis     = Poor
| frequency     = 
| deaths        = 
}}

'''Traumatic cardiac arrest''' ('''TCA''') is a condition in which the [[heart]] has [[asystole|ceased]] to beat due to [[blunt trauma|blunt]] or [[penetrating trauma]], such as a [[stab wound]] to the [[thorax|thoracic]] area.<ref name="hunt">{{cite journal |vauthors=Hunt PA, Greaves I, Owens WA |title=Emergency thoracotomy in thoracic trauma-a review |journal=[[Injury (journal)|Injury]] |volume=37 |issue=1 |pages=1–19 |date=January 2006 |pmid=16410079 |doi=10.1016/j.injury.2005.02.014 }}</ref> It is a [[medical emergency]] which will always result in death without prompt advanced medical care.  Even with prompt medical intervention, survival without [[neurological]] complications is rare.<ref name="pmid22108048">{{cite journal  |vauthors=Gräsner JT, Wnent J, Seewald S, etal |title=Cardiopulmonary resuscitation traumatic cardiac arrest--there are survivors. An analysis of two national emergency registries |journal=Critical Care |volume=15 |issue=6 |pages=R276 |year=2011 |pmid=22108048 |pmc=3388703 |doi=10.1186/cc10558 |doi-access=free }}</ref> In recent years, protocols have been proposed to improve survival rate in patients with traumatic cardiac arrest, though the variable causes of this condition as well as many coexisting injuries can make these protocols difficult to standardize.<ref name=":2" /> Traumatic cardiac arrest is a complex form of [[cardiac arrest]] often derailing from [[advanced cardiac life support]] in the sense that the emergency team must first establish the cause of the traumatic arrest and reverse these effects, for example hypovolemia and haemorrhagic shock due to a penetrating injury.{{citation needed|date=October 2021}}

== Mechanism ==
Traumatic cardiac arrest can occur in patients following any severe blunt or penetrating [[Chest injury|injury to the chest]]. Following the traumatic event, the heart ceases to pump blood through the body. Unlike medical cardiac arrest, there are several potentially reversible causes that may result in cardiac arrest in the setting of trauma. Clinicians will rapidly assess for these causes, and interventions will be directed to the specific cause.<ref name=":0" />

=== Massive hemorrhage ===
In both blunt and penetrating trauma, massive [[Internal bleeding|internal]] or [[Bleeding|external bleeding]] may decrease the volume of blood is available to be pumped by the heart to the body. This is considered [[Preload (cardiology)|preload]] dependent arrest.<ref name=":0">{{Cite web|date=2015-12-10|title=Traumatic Cardiac Arrest|url=http://www.emdocs.net/traumatic-cardiac-arrest/|access-date=2021-11-17|website=emDOCs.net - Emergency Medicine Education|language=en}}</ref>

=== Tension pneumothorax ===
[[Pneumothorax|Tension pneumothorax]] is caused when air is able to enter the space between the [[lung]] and the [[Thoracic wall|chest wall]], but is not able to escape. The increasing pressure within the chest cavity prevents blood from returning from the body to fill the heart.

=== Hemothorax ===
[[Hemothorax]] occurs when injury to the chest results in bleeding into the thoracic cavity. Similar to tension pneumothorax, increasing pressure prevents the return of blood from circulation to the heart.

=== Cardiac tamponade ===
In the setting of trauma, [[cardiac tamponade]] results from an acute [[pericardial effusion]], the accumulation of blood within the sac that surrounds the heart. As this sac is filled with fluid, the pressure on the heart is increased, and the chambers of the heart are unable to fill with blood.

=== Hypoxia ===
Inability to maintain [[Oxygen saturation (medicine)|oxygenation]] in trauma patients may be a result of [[Respiratory tract|airway]] compromise due to mechanical injury or obstruction or due to loss of the [[Control of ventilation|respiratory drive]] from [[Spinal cord injury|cervical spine]] or [[Nerve injury|peripheral nerve injury]].<ref name=":0" /> These conditions result in the [[Hypoxia (medical)|hypoxia]] that may lead to cardiac arrest.

== Signs and symptoms ==
[[File:Pulseless electrical activity EKG.svg|thumb|An example EKG for pulseless electrical activity. In this rhythm, cardiac activity will be seen on electrocardiogram, but a pulse will not be felt on provider's exam.]]
[[File:EKG Asystole.jpg|thumb|An EKG showing asystole, or "flat-lining."]]
Patients will present following a traumatic event most often with [[pulseless electrical activity]] (PEA). Patients will exhibit low blood pressure with pulses that cannot be palpated. Patients will progress into [[asystole]] if the underlying condition is not reversed. Other non-specific signs and symptoms associated with impending traumatic cardiac arrest may include sweating, [[Altered level of consciousness|altered mental status]], [[Tachypnea|rapid]] or [[Bradypnea|slow breathing]], and signs of trauma (bruising, [[Wound|laceration]], fractures, etc.).<ref name=":0" />

== Diagnosis ==
[[File:Echocardiogram 4chambers.jpg|thumb|Echocardiogram is a study in which an ultrasound is used to exam the function of the heart. In Traumatic cardiac arrest, an echocardiogram may show ineffective motion of the heart and may provide clues that point to a specific cause of the arrest.]]
Diagnosis of traumatic cardiac arrest is initially made with [[Electrocardiography|electrocardiogram]] with EMS or in the emergency department. Clinicians will also order diagnostic testing that may include [[Chest radiograph|chest x-ray]], bedside ultrasound and [[Echocardiography|echocardiogram]], and blood gas levels. A [[Blood transfusion|type and cross]] will be ordered to match the patient to receive blood transfusion if necessary.

Other work-up involved in diagnosis of a trauma patient may include [[Focused assessment with sonography for trauma|e-FAST]], [[RUSH exam]], [[Complete blood count|CBC]], pelvic X-ray, and [[CT scan|CT]] of the head, neck, chest, abdomen, and pelvis.

== Treatment ==
Treatment of traumatic cardiac arrest is guided by [[advanced trauma life support guidelines]]. Standard advanced cardiac life support guidelines are inappropriate for use in traumatic cardiac arrest, as they are directed primarily at treating pathology originating within the heart itself.<ref name=":1">{{Cite journal|last1=Smith|first1=Jason E|last2=Rickard|first2=Annette|last3=Wise|first3=David|date=January 2015|title=Traumatic cardiac arrest|journal=Journal of the Royal Society of Medicine|language=en|volume=108|issue=1|pages=11–16|doi=10.1177/0141076814560837|issn=0141-0768|pmc=4291327|pmid=25572990}}</ref> As clinicians begin to intervene, they will simultaneously seek reversible causes of the arrest. Management begins by establishing multiple points of IV access and evaluating the patient's airway and breathing. Other interventions may include [[Chest tube|thoracostomy]] and [[thoracotomy]], as well as treatment of the underlying cause of arrest.

=== Basic life support ===
[[Basic life support]] is commonly initiated by bystanders and first responders, but the role of basic life support in traumatic cardiac arrest is unclear. Basic life support is targeted to maintain oxygenation and circulation throughout the body, which can be lifesaving in cases of medical cardiac arrest, but does not address the frequent large volume blood loss encounters in many cases of traumatic cardiac arrest.<ref name=":1" />

=== Chest compressions ===
[[Cardiopulmonary resuscitation|Chest compressions]] are considered the most important initial intervention in cases of medical cardiac arrest, however studies evaluating their efficacy have excluded patients with traumatic cardiac arrest. Chest compressions work to replace the cardiac function of pumping blood throughout the body, however cases where the heart is either unable to fill with blood or the total blood volume is depleted, this intervention may be ineffective. Additionally, as many of the interventions targeted at specific causes of arrest are centered around procedures performed around the patient's chest, head, and neck, compressions may interfere with definitive management.<ref name=":1" />

=== Management of reversible causes ===
{| class="wikitable"
|+Reversible causes of traumatic cardiac arrest and treatment<ref name=":1" />
!Condition
!Goal of Treatment
!Initial Treatment
!Definitive Treatment
|-
|Hypovolemia
|Restore circulating volume
|Providers will initially establish [[Intravenous therapy|IV access]] to provide large volume fluid resuscitation and may use tourniquets or bandages to control bleeding
|These patients will likely require [[blood transfusion]] for definitive management
|-
|Tension pneumothorax 
|Relieve pressure within the chest cavity
|Initial treatment may include [[needle decompression]]
|Definitive treatment for most patients will include [[Chest tube|tube thoracostomy]]
|-
|Hemothorax
|Relieve pressure within the chest cavity
|
|Management requires [[Chest tube|tube thoracostomy]]
|-
|Cardiac tamponade
|Relieve pressure within the [[pericardium]]
|Initial treatment may require [[pericardiocentesis]]. This procedure may be sufficient to resolve the tamponade, or further management may be required.
|Patient with cardiac tamponade following penetrating trauma may be good candidates for [[thoracotomy]]
|-
|Hypoxia
|Increase oxygen content of the blood
|Treatment of hypoxia is aimed at maintaining the patient's airway and controlling breathing. Initial treatment may include [[Bag valve mask|bag-valve mask]], [[nasopharyngeal airway]], [[oropharyngeal airway]], or other airway devices
|Definitive management may require [[intubation]] or [[cricothyrotomy]]
|}

=== Future directions ===
Current guidelines tailored to treatment of specific causes of traumatic cardiac arrest have improved outcomes for patients, however these guidelines may be difficult to apply in a standardized manner due to differences in pre-hospital care and the wide variety of causes of traumatic cardiac arrest compared to medical cardiac arrest.<ref name=":2">{{Cite journal|last1=Lockey|first1=David J.|last2=Lyon|first2=Richard M.|last3=Davies|first3=Gareth E.|date=June 2013|title=Development of a simple algorithm to guide the effective management of traumatic cardiac arrest|journal=Resuscitation|language=en|volume=84|issue=6|pages=738–742|doi=10.1016/j.resuscitation.2012.12.003|pmid=23228555|doi-access=free}}</ref> Evolving algorithms are directed at quickly identifying incidences of cardiac arrest with a traumatic source and rapidly intervening to address reversible causes.<ref name=":2" />

==Prognosis==
Historically, traumatic cardiac arrest was thought to lead invariably to death. More recently, evolutions of advanced trauma life support guidelines and improved understanding of the underlying causes of traumatic cardiac arrest have improved outcomes for patients.<ref name=":1" /> Recent studies suggest that the survival rate for traumatic cardiac arrest is similar to that of all-cause cardiac arrest.<ref>{{Cite journal|last1=Lockey|first1=David|last2=Crewdson|first2=Kate|last3=Davies|first3=Gareth|date=September 2006|title=Traumatic Cardiac Arrest: Who Are the Survivors?|url=https://linkinghub.elsevier.com/retrieve/pii/S0196064406004124|journal=Annals of Emergency Medicine|language=en|volume=48|issue=3|pages=240–244|doi=10.1016/j.annemergmed.2006.03.015|pmid=16934644|url-access=subscription}}</ref> There is wide variability in the estimated survival rate based on factors that include initiation of pre-hospital care and nature of injury.<ref>{{Cite journal|last1=Barnard|first1=Ed|last2=Yates|first2=David|last3=Edwards|first3=Antoinette|last4=Fragoso-Iñiguez|first4=Marisol|last5=Jenks|first5=Tom|last6=Smith|first6=Jason E.|date=January 2017|title=Epidemiology and aetiology of traumatic cardiac arrest in England and Wales — A retrospective database analysis|url=https://linkinghub.elsevier.com/retrieve/pii/S030095721630538X|journal=Resuscitation|language=en|volume=110|pages=90–94|doi=10.1016/j.resuscitation.2016.11.001|pmid=27855275|url-access=subscription}}</ref>

Many patients who survive traumatic cardiac arrest may develop long-term neurological damage resulting from lack of circulation to the nervous system during the arrest. This damage may range from moderate disability to a persistent vegetative state. A 2012 review suggests that while survival rates of traumatic cardiac arrest are higher in children, so is the incidence of neurological complication.<ref>{{Cite journal|last1=Zwingmann|first1=Jörn|last2=Mehlhorn|first2=Alexander T|last3=Hammer|first3=Thorsten|last4=Bayer|first4=Jörg|last5=Südkamp|first5=Norbert P|last6=Strohm|first6=Peter C|date=2012|title=Survival and neurologic outcome after traumatic out-of-hospital cardiopulmonary arrest in a pediatric and adult population: a systematic review|journal=Critical Care|language=en|volume=16|issue=4|pages=R117|doi=10.1186/cc11410|issn=1364-8535|pmc=3580693|pmid=22770439 |doi-access=free }}</ref>

== References ==
{{Reflist}}

{{Chest trauma}}

{{DEFAULTSORT:Traumatic Arrest}}
[[Category:Heart diseases]]
[[Category:Medical emergencies]]
[[Category:Chest trauma]]
[[Category:Traumatology]]