Show Notes

Jeff: Welcome back to EMplify, the podcast corollary to EB Medicine’s Emergency Medicine Practice. I’m Jeff Nusbaum, and I’m back with my co-host, Nachi Gupta. This month, after a few months of primarily medical topics, we’re talking trauma, specifically Blunt Cardiac Injury: Emergency Department Diagnosis and Management.

Nachi: With no gold standard diagnostic test and with complications ranging from simple ectopic beats to fulminant cardiac failure and death, this isn’t an episode you’ll want to miss.

Jeff: Before we begin, let me give a quick shout out to our incredible group of authors from New York -- Dr. Eric Morley, Dr. Bryan English, and Dr. David Cohen of Stony Brook Medicine and Dr. William Paolo, residency program director at SUNY Upstate. I should also mention their peer reviewers Drs. Jennifer Maccagnano and Ashley Norse of the NY institute of technology college of osteopathic medicine and UF Health Jacksonville, respectively.

Nachi: This month’s team parsed through roughly 1200 articles as well as guidelines from the eastern association for surgery in trauma also known as EAST.

Jeff: Clearly a large undertaking for a difficult topic to come up with solid evidence based recommendations.

Nachi: For sure. Let’s begin with some epidemiology, which is admittedly quite difficult without universally accepted diagnostic criteria.

Jeff: As you likely know, despite advances in motor vehicle safety, trauma remains a leading cause of death for young adults. In the US alone, each year, there are about 900,000 cases of cardiac injury secondary to trauma. Most of these occur in the setting of vehicular trauma.

Nachi: And keep in mind, that those injuries don’t occur in isolation as 70-80% of patients with blunt cardiac injury sustain other injuries. This idea of concomitant trauma will be a major theme in today’s episode.

Jeff: It certainly will. But before we get there, we have some more definitions to review - cardiac concussion and contusion, both of which were defined in a 1989 study. In this study, cardiac concussion was defined as an elevated CKMB with a normal echo, while a cardiac contusion was defined as an elevated CKMB and abnormal echo.

Nachi: Much to my surprise, though, abnormal echo and elevated ck-mb have not been shown to be predictive of adverse outcomes, but conduction abnormalities on ekgs have been predictive of development of serious dysrhythmia

Jeff: More on complications in a bit, but first, returning to the idea of concomitant injuries, in one autopsy study of nearly 1600 patients with blunt trauma - cardiac injuries were reported in 11.9% of cases and contributed to the death of 45.2% of those patients.

Nachi: Looking more broadly at the data, according to one retrospective review, blunt cardiac injury may carry a mortality of up to 44%.

Jeff: That’s scary high, though I guess not terribly surprising, given that we are discussing heart injuries due to major trauma...

Nachi: The force may be direct or indirect, involve rapid deceleration, be bidirectional, compressive, concussive, or even involve a combination of these. In general, the right ventricle is the most frequently injured area due to the proximity to the chest wall.

Jeff: Perfect, so that's enough background, let’s talk differential. As you likely expected, the differential is broad and includes cardiovascular injuries, pulmonary injuries, and other mediastinal injuries like pneumomediastinum and esophageal injuries.

Nachi: Among the most devastating injuries on the differential is cardiac wall rupture, which not surprisingly has an extremely high mortality rate. In terms of location of rupture, both ventricles are far more likely to rupture than the atria with the right atria being more likely to rupture than the left atria. Atrial ruptures are more survivable, whereas complete free wall rupture is nearly universally fatal.

Jeff: Septal injuries are also on the ddx. Septal injuries occur immediately,