Blunt Cardiac Injury Guidelines

To trop or not to trop? Here's a brief review of the 2012 EAST trauma guidelines for BCI. 

What is BCI, anyway?

Describes a range of injuries due to blunt thoracic trauma: wall motion abnormalities, myocardial contusion, valve injuries, focal wall dilation, coronary injury, pericardial rupture, wall rupture

Right heart most commonly affected as it is most anterior.

Who to work up?

According to 2012 East guidelines: “patients with any significant blunt trauma toanterior chest should be screened.”

Also consider BCI in patients with persistent unexplained tachycardia, cardiogenic shock, or hypotension not explained by other injuries.

Now that I suspect BCI, what should I do?

Screening:

Screening consists of an EKG (Level 1 evidence) and a troponin (Level 3 evidence). Early studies suggested that EKG alone is sufficient to diagnose BCI, however multiple studies since then show that such an approach does not capture the small percentage of BCI patients that present with normal initial EKG and positive troponin. 

A normal EKG and troponin rules out BCI (even in the setting of a sternal fracture, which is not predictive of BCI). Several studies show that the addition of troponin raises the NPV to 100%. Same screening approach is supported for pediatric pts.

Management & Disposition: 

Management is supportive; severe trauma may require surgical repair. 

Patients who have a new abnormality on EKG (arrhythmias, ST changes, heart block, PACs or PVCs, ischemic changes, etc) must be admitted to a telemetry floor for continuous monitoring. 

A new dysrhythmia or hemodynamic instability warrants an echo, preferably TEE over TTE.

Note that degree or persistence of elevation of troponin does not correlate with prognosis.

The chicken or the egg…did an MI precede the MVA or is it BCI?

It is important to differentiate which patients need cath with anticoagulation and which patients would be harmed from it. Can be differentiated via ekg-gated CT angiocoronaries.

Read more at:
http://www.aast.org/blunt-cardiac-injury
https://www.east.org/mobile/practice-management-guideline/96

Traumatic Hemothorax

Case: 18 y/o M is wheeled in with a stab wound to the left chest. VS: HR 130, BP 95/45, RR 30, SpO2 92% on 15L NRB. Pt is maintaining airway, no tracheal deviation, diminished BS on the left, strong distal pulses. You place a left-sided 36F chest tube with immediate blood return. 

What are the possible etiologies of traumatic hemothorax?

Laceration/injury to the heart, major vessels, intercostal vessels, mammary arteries, thoracic spine, diaphragm or lung parenchyma. 

How reliable is the FAST exam in diagnosing a hemothorax?

Sensitivity is 92-96% however bear in mind that the presence of subcutaneous air or concomitant PTX may obscure the underlying blood.

How much blood must be present to diagnose a hemothorax on CXR?
For upright CXRs, 150-300mL of blood causes blunting of the costophrenic angle. However, most trauma will have their CXR done in a supine position, which has a low sensitivity 35-60%. It may take 1L of blood distributed throughout a supine hemithorax to develop haziness on a supine film!

What defines a massive hemothorax?
Traditionally:

-Immediate drainage of 1.5L (or 15mL/kg) or 1/3 of blood volume
-Drainage of 200mL/h (or 3mL/kg/h) x 2-4 hours plus persistent need for blood products

Other definitions:

How to manage a massive hemothorax post thoracentesis?

Address hypoxia by keeping patient on oxygen and may attempt to position so that affected lung is down (if permitted by lack of other injuries). Resuscitate with 1:1:1 blood products. These patients benefit from thoracotomy in the OR as soon as possible. 

What are the long-term complications of not adequately draining a hemothorax?

Retained hemothorax consisting of clotted blood can form, which is not easily drainable by a chest tube. A traumatic hemothorax is also a nidus of infection; these patients are at risk of developing empyemas.

More pressure more problems

High Pressure Injection Injury Occurs when fluid is expelled at least 100 pounds per square inch.  The fluid punctures skin and can dissect up along facial plains, neurovascular bundles, and tendons.   This can easily cause compartment syndrome, deep infections, and debilitating fibrosis.  Extremity necrosis can develop within 12 hours.  Even with expeditious OR debridement and washout there is a 38% risk of amputation and with caustics or higher pressure the risk is up to 80%.  Those that keep their limb lose a great deal of functionality.

Demographic:

• Young adult typically male injured non-dominant hand

• Inexperienced operator of equipment

• exposure material is paint, grease, water, oil, diesel, paint thinner,

Acute phase

• onset within 4-6 hours

• paresthesias, pain, swelling,

• vascular compromise

• compartment syndrome

• injury site may have no skin perforation or small subtle pinhole

ED steps:

1. Recognize this minuscule puncture site is a huge life changing problem

2. Broad spectrum antibiotics

3. Tetanus

4. Hand consultation for OR wash out/debridement

5. X-ray--> lead base paint is radio opaque but may appear like calcifications. Other paints will show sub-cutaneous emphysema. Grease will appear as a lucency.

6. analgesia

7. council patient of detriment to extremity function