Blunt Cardiac Injury, Esophageal Injury, Diaphragmatic Injury

00:01 Now, let's move on to a different clinical scenario.

00:05 Let's say the patient now is a 60-year-old man who sustains a head-on collision and there's deformity of the steering wheel and there was airbag deployment.

00:14 The patient is conversant and is orientated at the scene with a normal blood pressure, but he complains of severe breastplate pain.

00:23 What injuries are you suspecting at this time having received this report? I'll give you a second to think about it.

00:32 Your differential diagnosis should include a sternal fracture, sure.

00:36 As the airbags are so important savings lives, however, the force at which it deploys can often cause sternal fractures.

00:46 And of course, myocardial injury, also known as blunt cardiac injury.

00:52 We used to call this cardiac contusion, but we don't call it that anymore because it's clearly a spectrum of diseases.

01:00 Let's start with sternal fractures.

01:02 Here on this cross-sectional CT chest, you notice that the sternum is fractured.

01:07 Again, sternal fractures in and of themselves are not so important.

01:10 They cause pain and the patient can splint.

01:12 So you want to make sure the patient has adequate pain control.

01:16 I remember, sternal fractures can be difficult to diagnose and appreciate on plain x-rays particularly if they have had previous cardiac surgery like our patient and has sternal wires.

01:26 Now, let's discuss blunt cardiac injury.

01:29 It's similar to patients who develop multiple rib fractures and underlying pulmonary contusion.

01:35 The right ventricle is particularly susceptible injury because it's so close to the sternum and the surface that is exposed to injury is far bigger than any other chamber.

01:49 Here, we get an EKG or 12-lead EKG on our patient suspected of blunt cardiac injury.

01:54 It's important to remember, however, the severity of the sternal fracture or even the presence of the sternal fracture does not actually indicate that the patient is more likely to have a blunt cardiac injury.

02:06 Here on this EKG, take a look at it.

02:09 You can pause the video, and see that there are 1 millimeter ST segment elevations in the lateral leads with associated right bundle branch block.

02:17 All concerning for blunt cardiac injury.

02:21 If you decide that the patient in fact is at risk or has blunt cardiac injury, either diagnose with EKG abnormalities or a rise in the troponin level, the patient should be admitted and watch by telemetry.

02:34 However, if the EKG is completely normal and the troponins are negative, usually the patient can be sent home as long as they don't have any other injuries.

02:44 Should we get any additional studies for blunt cardiac injury? Well, like I said if there's any hemodynamic instability, go ahead and get an echo, take a look at whether or not the right ventricular function is normal.

02:55 In the absence of hemodynamic instability, it's usually not very helpful.

03:02 Now, quiz time.

03:04 Take a look at this image.

03:05 What's wrong with that? The hints are in the white arrows.

03:09 I'll give you a second to take a look at this.

03:15 That's right, the patient has a widened mediastinum and anytime you see a widened mediastinum in a trauma patient, you should have concern for aortic injury.

03:27 In this 3D reconstruction of the aortic anatomy, you see the results of an endovascular repair of a traumatic pseudoaneurysm.

03:34 Nowadays, endovascular repair of the Type B dissection involve the descending aorta is very popular and supplanting left thoracotomies and open procedures.

03:42 However for Type A dissection sternotomy and open repair is the standard.

03:50 Let's pose a question.

03:52 In the scenario where a patient presents to the trauma bay is hypotensive and demonstrates a widened mediastinum, what's your next step in management? I'll give you a second to think about it.

04:04 Of course, ABCs.

04:05 I know it seems silly, but you get the point.

04:08 We always start with airway, breathing, circulation, but very importantly, the take-home message here is this.

04:14 For circulation, it is very unlikely that a widened mediastinum is actually the cause of hypotension.

04:20 Therefore, you have to go look for other sources of bleeding.

04:26 And the answer is an eFAST.

04:28 We'll get to that in a little bit.

04:31 Remember, any time you have a hypotensive patient statistically speaking, it's bleeding until proven otherwise.

04:41 Let's move on a little bit.

04:43 Here, also in the thorax of course is the esophagus.

04:46 Esophageal injury is demonstrated by CT scans is usually indirect findings and the most common indirect finding is a mediastinum that has air or called a pneumomediastinum.

04:58 By the time you have dysphagia or pleural effusion, it's usually a late finding.

05:03 High index of suspicion is very important.

05:05 And of course, if you have a knife or a sword stab wound to the chest, you have to consider esophageal injury as a possibility.

05:12 Given pneumomediastinum and a mechanism that suggests that there may be either a tracheal or esophageal injury, patients undergo what's called a triple scope.

05:22 They include bronchoscopy to look at the major airways, esophagoscopy to look at the esophagus.

05:31 This is typically done in a rigid fashion as opposed to an EGD, which is a flexible scope that goes into the stomach and duodenum.

05:39 And lastly, a laryngoscopy to evaluate the upper airway.

05:43 Here, you see an image of the vocal cords.

05:47 Now, some important esophageal injury principles.

05:50 Remember, esophageal injuries are associated with other mediastinal structures.

05:55 That's where we get 3 scopes.

05:57 If you have an esophageal injury, you may also have a tracheal injury.

06:01 Early repair is preferred if you identify it.

06:04 That's because if it's delayed in terms of diagnosis, the patient may become septic.

06:09 Review the septic lecture module for more information.

06:16 Now, let's move on to our favorite test topic which is the diaphragmatic hernia.

06:22 Diaphragmatic hernias are difficult to diagnose.

06:25 And once again, it's one of those entities where you need to have a high index of suspicion.

06:29 Clearly, our patient has a risk of diaphragmatic injury.

06:33 In this chest x-ray that includes the upper cuts of the abdomen, this is as clear as it gets.

06:38 You see an air bubble within the left thorax, that's likely the stomach.

06:42 Clearly, the stomach doesn't belong in the left thorax.

06:45 There's only one way that happened.

06:47 There's a diaphragmatic hernia.

06:51 Now, in practice, it's rarely this clear.

06:53 Usually even with cross-sectional imaging that is high definition, it's still very, very hard to detect.

06:58 Therefore, you have to have a high index of suspicion.

07:01 And also, diaphragmatic hernia may cause respiratory distress because of the possibility of phrenic nerve paralysis.

07:10 All diaphragmatic injuries need to be repaired particularly on the left side as they're unlikely to fix themselves.

07:16 And again, to remind you, they are difficult to diagnose on x-ray or cross-sectional imaging.

07:23 Now, it's time to review some important clinical pearls and high-yield information.

07:28 Recall that any stab wound to the chest may also involve the abdomen and diaphragm.

07:33 Therefore, a high index of suspicion is necessary.

07:37 Additionally, remember the very important concept of tension pneumothorax.

07:41 It's a clinical diagnosis, hypotension, distended neck veins, and of course a clinical picture that's consistent with the possibility of a pneumothorax.

07:51 Thank you very much for joining me on this discussion of thoracic trauma.