SAN DIEGO – The few trauma patients who will survive a high-risk thoracotomy procedure for cardiac arrest can be predicted by the presence of cardiac motion as detected by a quick and inexpensive bedside ultrasound, a prospective study conducted at a level I trauma center showed.
Focused assessment with sonography in trauma (FAST) was 100% sensitive and 62% specific in predicting those who would survive or be eligible for organ donation after receiving a resuscitative thoracotomy for traumatic cardiac arrest, said Dr. Kenji Inaba of the department of surgery at the University of Southern California Medical Center in Los Angeles.
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Resuscitative thoracotomy, said Dr. Inaba, is a salvage procedure performed after cardiac arrest. It is a “high-risk, resource-intensive procedure, with a low quantitative yield. And yet, patients do survive.” Previous retrospective studies found that of those receiving resuscitative thoracotomy for traumatic arrest, 7.4% survived, with more than 90% of survivors retaining neurologic function; an additional 4.2% of recipients were potentially eligible for organ donation. Thus, a tool to identify potential survivors among those who present in post-traumatic cardiac arrest would help avoid unnecessary use of a procedure with such risks and resource burdens.
FAST, an inexpensive procedure that is standard for other indications in trauma, has been effective in identifying potential survivors in thoracotomy for nontrauma cardiac arrests, Dr. Inaba said at the annual meeting of the American Surgical Association.
The technique “has near-universal availability, can be performed immediately at the bedside without moving the patient, and yields real-time results with no radiation involved,” he said.
For the current prospective study, the specific aim was to examine the ability of FAST to differentiate survivors and potential organ donors from those who would not survive resuscitative thoracotomy among those presenting in traumatic cardiac arrest. Dr. Inaba and his associates examined the predictive value of cardiac motion and the presence of pericardial fluid for survival, as well as the adequacy of the FAST study for each patient.
The single-center study, conducted from 2010 to 2014, enrolled 187 patients (mean age, 31; 84.5% male) presenting in traumatic arrest who received resuscitative thoracotomy in the emergency department and also received a FAST. The scans were performed by emergency medicine residents under direct faculty supervision. Of the 187 patients studied, 6 (3.2%) survived, 3 (1.6%) became organ donors, and 178 (95.2%) died but were not organ donor eligible.
Cardiac motion was detected by FAST in 54 (28.9%) individuals in the total study population; among these were all nine of the survivors and donors, yielding a sensitivity of 100% and a specificity of 73.7% for survival (P < .001). All 16 of the patients with pericardial fluid detected by FAST died, as did all 7 patients in whom the study was deemed inadequate. Put simply, Dr. Inaba said, “no cardiac motion equals no survival.”
If thoracotomies had been performed only on patients in the study group who had cardiac motion on FAST, more than half of the unsuccessful resuscitative thoracotomies would have been avoided, Dr. Inaba noted. The study, he said, has particular application for lower-volume trauma centers, which must carefully weigh the prolonged use of limited resources required in a resuscitative thoracotomy.
Dr. David Spain, chief of trauma and critical care surgery at Stanford (Calif.) University, asked whether the study captured the mechanism of injury. Though the study did not do so, said Dr. Inaba, he and his colleagues realized that a subset of patients who went immediately to the operating room were not included in the study, a potential limitation. This group of patients included those with a penetrating cardiac injury – a possible reason, he said, why no patients among the survivors had a cardiac injury.
The authors reported no relevant financial disclosures.