Blunt and PenetratingChest Trauma

Adam Oster R4Arun Abbi, MD FRCPCore RoundsSeptember 9, 2004.

Topics

Blunt Aortic Injuries Myocardial Contusion Occult Pneumothorax ED Thoracotomy Hemothorax Pulmonary Contusion

Penetrating Pneumothorax Tamponade

Case 1

23M unrestrained driver struck a light pole at highway speeds. Ejected. Found 20meters from his car. GCS 9 Hemodynamics normal Facial trauma

Case 1

Blunt Aortic Injury

MC mechanism is… Rapid deceleration

Why? Aortic arch is mobile and descending arch is

immobile d/t ligamentum arteriosum Rapid deceleration places aortic isthmus under

tension shearing stress can result in tearing opposite to fixation site.

90% die on scene Remaining 50% within 24hrs without prompt

definitive treatment

Adam Oster

JT Jan 2001.

Blunt Aortic Injury

Clinical presentation… Sensitivity of screening DI (CXR) Imaging controversies;

CXR vs CT CT vs angiography CT vs TEE

Blunt Aortic Injury

Sensitivity of the CXR What are the high risk findings?

Mediastinal widening (>8cms?? – 1970s Marsh and Sturm)

Apical cap Loss of AP window Loss of aortic knob Rightward deviation of NG (of the T3/4 SP) Rightward deviation of the trachea Downward displacement of lt mainstem Thickening of right paratracheal stripe (>5mm)

NB isolated # 1st/2nd ribs are not predictive of injury

Blunt Aortic Injury:Sensitivity of the CXR

Sensitivity of CXR approx 90% Loss of aortic knob (sens= 53-100%, spec 21-55%) Mediastinal widening (sens= 81-100, spec. 10-60%)

Def’n of widening is ambiguous in the literature >8cm at origin lt subclavian or Ratio of mediastinal width to width of thorax at aortic knob

Sensitivity of the CXR Approx 90-98% NPV of a normal CXR is 96% CXR can be normal in up to 5% with TAI Cannot completely r/o the injury Take into account pre-test probability PPV low 5-20%

Blunt Aortic Injury and the CXR Radiology 1987. vol. 163 (abstract only) N=205 retrospective review with BCT

41 with angiographically-proven BAI Analyzed 16 distinct CXR features most discriminating signs were

loss of the AP window, abnormality of the aortic arch rightward tracheal shift widening of the left paraspinal line No single or combination of radiographic signs

demonstrated sufficient sensitivity to indicate all cases of traumatic aortic rupture on plain chest radiographs

The bedside anteroposterior upright view of the chest proved far more valuable than the supine view in detecting true-negative studies.

significant reader variability

Blunt Aortic Injury

Journal of Trauma. July, 2004 Mediastinal width (MW), left mediastinal width (LMW) and

the ratio (MWR) measured on resusc CXR GS = either surgery or angio

51 had CT, 45 had aortogrpahy, 6 thoracotomy after CT

Results 21/51 TAI Surgically-proved in

20 Successful repair in

18 19/20 pathology at

isthmus

Results Best combination

predictor is LMW >6.0 and MWR >0.60

LR = 3.0

Blunt Aortic Injury

Blunt Aortic Injury

Blunt Aortic Injury

Journal of Trauma. December, 2001. Prospective, n=93

MVC >10MPH (76%) Fall >5ft (24%) Excluded hemodynamically unstable and severe HI All had CXR and CT

Sensitivity 82% Specificity 57%

CXR missed 2/3 BAI

Sensitivity of CXR for Chest Injuries

Blunt Aortic Injury

7.3% with confirmed TAI had normal mediastinum on CXR.

Blunt Aortic Injury: The CXR

Retrospective review of white peoples CT chest to determine normal AP width Excluded abnormal mediastinums Mean width 6.1cms on CT

Modern trauma rooms 7.3-7.92 cms Historic upper limit of normal does not apply

FFD and OFD

The CXR in BAI

Emergency Medicine Clinics of North America. February, 1999. Meta-analysis. Most specific findings

Lt tracheal deviation (80-95%) NG deviation (90-94%) Depressed lt mainstem bronchus (80-100%)

No association with sternal # or thorasic rib#

Blunt Aortic Injury: Identification by Mechanism

Journal Of Trauma. June 1, 2001.

Blunt Aortic Injury: Identification by Mechanism

Retrospective review of crash site data GS was radiographic

or autopsy N=34 (12%) Head-on crash = 5% Side impact = 59%

(20/34) 74% in compact

cars 65% vehicle-vehicle 35%

vehicle-pole/wall##Presence of delta V>20mphor near-side impact was present in All TAI. Either had NPV =100%

Mechanics

Blunt Aortic Injury: Identification by Mechanism

Journal of Trauma. April, 2003.

Cohort design. NASS database.

Independent positive predictors for BAI Age > 60 Front-seated Frontal and near-

side impacts Delta V>40mph Crush >40cms Intrusion >15cms

Negative predictors Seat-belt use Occupant of large

vehicle

Blunt Aortic Injury: Identification by Mechanism

Journal of Trauma. Jan, 2001. Retrospective autopsy review of all BAI.

N=242 (12% all trauma deaths) MC mechanism

Head-on>side-impact

CXR Abnormal

How to diagnose BAI CT Angio TTE TEE OR

CT vs Angiography

Parallel CT and angiography for n=142 with suspected BAI

All had “unclearable” CXR Blinded Radiologists

CT vs Angio

CT neg = 121 (kappa 0.7) CT pos = 7 (kappa 0.9!) Sens = 100% NPV = 100% Spec = 87% $500 cost savings/pt

CT vs Angiography

Journal of Trauma. Feb, 2004.

CT vs Angiography

Retrospective registry data

All pts had aortography Most had CT Findings confirmed

surgically

NB CXR normal in 7% Non-specifically

abnormal in 53% (BAI not suspected)

CT vs Angiography

CT performance 1 miss 5 FP Agreed in 93 cases

Sens = 87% Spec = 98%

Chest, 1997. Prospective review of TAI patients

(n=28) confirmed by angio/surgery/MRI All had TEE Control group of 30 with chest trauma

and wide mediastinum but no TAI Describe the echo findings associated

with TAI

MC findings Thick stripe Intimal lesions False aneurysms Aortic wall hematoma

TEE for Detection of Mediastinal Lesions

Journal of Trauma, 1995. Prospective, n=70. All intubated TEE within 48hrs

TEE for Detection of Mediastinal Lesions. Journal of Trauma, 1995.

But… Only 1 lesion Unclear GS ?blinded to other investigations

TEE

Smith et al. NEJM, 1995. Prospective, n=93 TEE followed by angio GS = angio/surgery/autopsy Mean time to TEE 29mins Sens = 100% Spec 98%

TEE

Chrillo et al., Heart. 1996. Prospective, consecutive, n=134. Clinical evidence chest trauma or

mechanism Sens = 93% Spec = 98% Time to surgery shorter (30 vs 71mins)

Blunt Aortic Injury

Journal of Trauma. Jan, 2004. Retrospective registry data Early repair = <16hrs from injury Case controlled comparisons

Delayed vs Early Repair

Delayed vs Early Repair

Delayed vs Early Repair

Delayed repair does not appear to be associated with increased mortality

BAI should be triaged and given appropriate priority but should not take precedent over other co-existing injuries

May lead to increased morbidity LOS especially

…medical management of blood pressure

BAI and Anti-Hypertensives

Annals of Surgery 1998. Prospective use of labetolol or esmolol +/-

nitroprusside To SBP= 100, HR<100 Nitroprusside added if unable to optimally control

BP Outcomes

Rupture prior to repair Allowing delayed repair if co-existing injuries

necessitated N=71 with BAI

BAI and Anti-hypertensives

58 received medical therapy 18 did not d/t instability or normotension

None ruptured prior to operative management and none died from their BAI

Small numbers…

Blunt Aortic Injury

15000 patients screened by CT 198 suspected of BAI

BAI in 87 9 had MAI (diagnosed by IVUS)

<1cm intimal flap with none to minimal periaortic hematoma) 1 had surgery, 2 died (non-aortic death) Remaining 6 had follow-up studies ay 3-8wks (2 flap stable,

1 resolved, 3 psuedoaneurysm)

Minimal Aortic Injury:IVUS

BAI:Take Home CXR may miss up to 7% The “wide mediastinum” is a weak

radiographic predictor CT if CXR abnormal CT if big mechanism Consider TEE if unstable Can delay repair if other injuries priority Are some lesions which can be

managed conservatively

Case

24M Intubating for CHI CXR looks okay

Occult Pneumothorax and PPV

Incidence depends on population studied 5-8% of all injured patients 2% in peds Approx 25% of all CT-Dx PTX Higher (upto 50%) in critically ill patients

Occult Pneumothorax and PPV:Do They Progress?

Limited evidence 2 small prospective studies

1993 Enderson Randomised 40 pts with OP to CT or no CT

without regard for PPV ICU patients 21 patients had OP ‘observed’ 15/21 observed ventilated 8/15 (53%) ‘progressed’ [3 had tension

PTX) None with chest tube progressed

Occult Pneumothorax and PPV:Do They Progress?

1999 Brasel Prospective, randomised trial of 39 patients

with 44 OP Patients in OR 9 pts ventilated in each group 2/9 without CT progressed No differences in complications or urgent

tube placement for cardiovascular deterioration

NS

Occult Pneumothorax and PPV:Do They Progress?

Summary Total of 33 ventilated pts with OP

randomised to chest tube Appear to be failure rates of approx 30% with

‘observation’

What if you’re going to fly with them…?

Case

35M High speed, unrestrained front end collision at high

speeds. Crushed steering column Significant anterior chest trauma Sternal fracture, pulmonary contusion

You’re worried about a myocardial contusion Do you want a Trop? ECG?

Myocardial Contusion

What is it? What is the accuracy of TnT and ECG

for the diagnosis? What is the GS? Who do you need to observe? Who should you work-up?

Myocardial Contusion

Risk of BCI with isolated sternal fracture Annals Royal College of Surgeons of

England, 2000. 37 pts with isolated sternal # 1 patient had BCI 8 patients had abnormal ECG none had

BCI

BCI: Who Should You Work Up? Nagy KK, Krosner SM, Roberts RR, et al (Cook

County Hospital, Chicago, IL; Rush University, Chicago, IL) World J Surg. 2001;25:108-111

Patients at risk for BCI admitted to ICU for serial ECGs, monitoring, serial enzymes and Echo. N= 171 (group 1).

Group 2 = no risk factors and hemodynamically stable. Results:

normal ECG, normotensive and no dysrhythmias on admission had benign outcomes.

Those with ST segment changes, dysrhythmias, or hypotension after blunt chest trauma need to be monitored for 24 hours; they occasionally need further treatment for complications of BCI. No additional information was gained by using ECHO for screening

Myocardial Contusion: Troponin T

Does a positive put you at higher risk? Does a negative R/O? Should you order it?

Myocardial Contusion:Troponin T

Prospective, consecutive pts with blunt chest trauma and suspected BCI, n=94. Entered into a 18mo protocol GS = ‘significant’ ECG or ECHO findings Blinded evaluators

Myocardial Contusion:Troponin T

Myocardial Contusion:Troponin T BCI diagnosed in 26 No in-hospital cardiac compressions f/u available (mean 16mo) for 88%

No pt with any long-term complications

TnT positive in 12% of pt with BCI Negative in all without BCI

No relationship between pos trop and clinical outcomes.

Myocardial Contusion: Is There a Low Risk Group?

Journal of Trauma. Jan, 2003. Prospective and consecutive major blunt chest

patients. N=333. All had serial ECGs and TnI Echo prn

Myocardial Contusion: Is There a Low Risk Group? Outcome = sigBCI = heterogeneous

def’n Hypotension presumed to be cardiogenic

in origin, arrhythmia, abnormal post-traumatic TTE with low CI.

Results 44 (13%) sigBCI

22 diagnosed by TTE/TEE 5 required surgical repair 5 cardiac deaths

Myocardial Contusion: Is There a Low Risk Group?

Myocardial Contusion: Is There a Low Risk Group? ?timing of tests There was 1 patient (2%) who was

initially TnI neg but then became TnI positive ?need test done at 10hrs

Normal ECG and TnI (maybe TnT) at 10hrs effectively R/O the diagnosis

Abnormal ECG and pos TnI (maybe TnT) is non-specific for the disease.

BCI:Take Home ECG is the best screening test

Optimal period of observation is unknown Enzyme have no role, are not predictive

of disease or absence of disease Echo is not a screening test Positive echo does not predict clinical

complications Use echo to r/o tamponade or cardiac

rupture

Crack the Chest?

33M in MVC Significant blunt chest injuries Hypotensive en route Loses VS as the helicopter landing

33M Stabbed under xiphoid BP 40/P

33F Shot in Rt anterior chest Losses vitals on scene

(what if looses vitals in ED)

ED Thoracotomy:Practice Management GuidelinesJournal of the American College of Surgeons, 2001.

Recommendations based on meta-analyses. Mostly Class III. Overall survival all-comers

7.8% Penetrating chest survival

11.16% Blunt survival

1.6% Neurologic outcomes

In series reporting… 5% survival 85% neurologically intact

ED Thoracotomy:Practice Management GuidelinesJournal of the American College of Surgeons, 2001.

Penetrating Chest Trauma Penetrating cardiac 363/1165 = 31.1%

Pediatrics 9/142 = 6.3% all-comers

Penetrating 7/57 = 12.2%

Blunt 2/85 = 2.3%

ED Thoracotomy:Practice Management GuidelinesJournal of the American College of Surgeons, 2001.

Recommendations: Best applied to;

Penetrating Cardiac With witnessed signs of life in the field or ED Survival is 30%

Non-cardiac penetrating Difficult to ascertain – can use EDT to

differentiate Survival is 10%

ED Thoracotomy:Practice Management GuidelinesJournal of the American College of Surgeons, 2001.

Recommendations Rarely performed

Blunt with loss of vitals in ED Survival 1.6%

ED Thoracotomy

Journal of Trauma. June, 2001. Established an institutional guideline for EDT in 1991

based on local review of survivors and neurologic status. Penetrating chest with diagnosis of tamponade with

signs of mentation in field or in ED. 6yr retrospective review post-implementation (1992-

1998)

Adam Oster

NB still pts undergoing EDT outside of protocolGroup 1 -- 20 x penetrating chest 1xMVCGroup 2 -- 27 - penetrating chest 1xMVCGroup 1 non-survivors -- despite apparent chest injuries, deaths were d/t abdominal injuriesNB if applied appropriately, group 1 survival =48%

Case

Case

EDT

Case

Case

Hemothorax

Indications for chest tube Any hemo that you can see on CXR CT much better at quantifying and

identifying underlying injuries/complications Can miss up to 1000cc in supine film

Hemothorax

Indications for Thoracotomy >1500cc initially >200cc/hr >2hrs Ongoing transfusion requirements??

Case

Case

The Physical Exam:Sensitivity for Hemothorax and Pneumothorax

Journal of Trauma. December, 2002. Prospective, non-consecutive, n=676 (523 blunt) Blunt and penetrating chest trauma Signs and symptoms of hemothorax and pneumothorax

defined apriori

Accuracy of the physical exam dissimilar for penetrating and blunt trauma

Eg sens/NPV for auscultation 100% for blunt but 50% for penetrating

??specificity of auscultation is 100% for disease in penetrating

But, non-blinded to CXR… Disease spectrum? Did not demonstrate altered

management

Resuscitation 2002. Retrospective review of patients with

pulmonary contusion and with high FiO2 requirements (FiO2/PaO2 <300)

Looked at those managed with non-invasive support (CPAP, BiPAP)

N=12 All survived to discharge

Critical Care Medicine, 2004. Retrospective review of patients ventilated

using the Open Lung Concept and pre-designed Recruitment Maneuvers

PCV Vt <6cc PEEP 5-17 CT pre and post RM

Case

Diaphragmatic Rupture

Uncommon 0.8 to 8% hospitalised chest trauma Laterality?

Lt sided upto 90% d/t protection by liver and postulated lt sided weakness

Often initially missed on CXR unless frank herniation of gastric content into thorax

CT sens approx 84%, spec 77% GS = exploratory laparotomy

Diaphragmatic Rupture

Pneumothorax

Open PTX