Crash Deconstruction

The evening hours are crisp, and the Attack One crew is leaving to perform a standby assignment at a local football game. But their trip is interrupted when tones drop for a reported motor vehicle accident. As they confirm their response, the dispatcher gives additional information: A vehicle and a truck are involved, and one driver is unconscious.

“Uh-oh,” the Attack One officer says to the other crew members, “an early start on a Friday night. Go ahead and get the trauma gear ready.”

As they arrive at the intersection, there are no signs of a major collision, and the dispatcher is asked for further information about a location. The dispatcher suggests they check farther north, and about half a block away they find several people talking with the driver of a car that sits at an unusual angle. The people wave to the crew, which reports to the dispatcher that the accident has been located.

“Attack One on the scene, dispatch. We have a car that has struck a parked truck, with very minor damage. We will be checking for injuries.”

The officer does a quick 360-degree evaluation of the scene and finds the car struck with very little impact, and the truck is not damaged. No fluids are leaking, and no airbag has deployed. But an elderly lady standing on the sidewalk with her dog asks if she can speak.

“Yes, ma’am, did you see this happen?” the Attack One officer asks.

“Yes, I did,” the lady responds. “I was walking toward the man, and I noticed his car was moving slowly, and it looked like he was asleep as he drove toward me. Then he bumped into the truck. I asked if he was OK, and he didn’t respond for about a minute. Then he woke up and asked me what happened. I had called 9-1-1 already. Is he OK?”

“We are checking him out now, and we hope he is OK,” the officer tells her. “That’s important information, and we appreciate you remaining here to tell us. Will you please stay until the police officers arrive and tell them the same thing? Did those other people see the accident also?”

“No, I was the only one here when it happened,” the lady says. “They just pulled up and started talking to him.”

The officer goes to relay the bystander’s information to his fellow crew members. He reports the minor damage to the vehicle. The driver, an older man, is held in place by a lap and shoulder belt; he complains of back pain. He’s told the EMTs he doesn’t remember what happened and wants to get out of the car.

“Let’s check him out completely before we allow that, because the witness says he was unconscious when he rolled into the truck.”

The Attack One paramedic begins to interview the patient, trying to gather any information he might have on what caused this low-impact accident and his possible loss of consciousness. The man denies headache, chest discomfort, palpitations or dyspnea. He continues to say his back is a little uncomfortable, and he might be getting nauseated. He ate lunch hours ago, has not vomited and does not have diabetes. Years ago he was told he had high blood pressure, but he rarely gets it checked and only takes his medication when he thinks he needs it. “I don’t like going to doctors,” the man says. “They try to find problems.”

His mental status is now clear. He has a pulse rate around 60 but looks a little pale. He again asks if he can get out of the car.

“Why don’t we check your blood pressure before we do that?” the paramedic replies. “Let’s make sure nothing serious is going on with your back before you get out and make it hurt worse.”

The EMTs find a blood pressure of 120/70. “Maybe his blood pressure problem went away,” they report to the paramedic.

They palpate his back from top to bottom and find no tenderness or signs of injury. The man has been moving his neck around actively, so the paramedic finds no indication of neck injury and no need to restrict spinal motion.

“All right, let’s get you up slowly, but if your back hurts, we’re going to sit you back down and remove you on a hard board. You let us know, OK?”

They open the driver’s door and help the man pivot around and start to put weight on his legs. He stands up but quickly reports, “I don’t feel good!” Then he plops back down in the driver’s seat.

No back pain, he says, just very light-headed. The paramedic can’t feel a pulse at his wrist and asks the EMT to check a blood pressure. He can feel a brachial pulse with the same rate, about 60 beats a minute, but the blood pressure cuff removes the pulse at about 70 mmHg.

“Maybe we found the cause of this accident,” the paramedic tells the patient, “because your blood pressure is too low to allow you to stand up.” Then he directs his crew, “Get a board to assist in moving him to the stretcher, and let’s get him in the ambulance.”

Lying on the stretcher the man feels better and responds to the paramedic’s new questions about whether he has noticed any blood in his bowel movements or other unusual bleeding. Again the answers are all negative.

The paramedic reports to the police officer that there may have been a medical problem that caused the accident, and that something is going on that makes the paramedic uncomfortable, so they are going to do a quick evaluation and then head to the trauma center.

In the ambulance, the crew quickly obtains a 12-lead EKG, which is normal. His pressure is about 110/70 while lying flat on the stretcher, and he doesn’t want to try to sit up again. His back is still painful, and he is a little nauseated but has no other symptoms.

The patient has had some type of acute medical event, then very minor trauma, and now has mild back discomfort. He does not meet trauma alert criteria, but the paramedic is suspicious of some event, and the low blood pressure, and the history of unconsciousness. Almost apologetically, he calls the trauma center to report. The patient has an intravenous line started, is placed on a monitor and is given supplemental oxygen.

The paramedic checks one more blood pressure as they near the hospital. Lying down it’s now 100 palpable.

Hospital Course

The trauma center doors open, and the staff members are all busy caring for other patients. The crew moves the patient to one of the lower-acuity rooms and begins to offload him before the first nurse arrives. The patient is more uncomfortable now, and the paramedic asks the nurse to check his vitals. His blood pressure is first reported at 90/60, with a pulse rate of 60.

“Something has to be going on with this man. Do you mind if I go get a physician?” the paramedic requests.

The nurse is also very concerned. “Let’s go together and take this nice man with us to one of the trauma bays.” The bed wheels down the hallway, an emergency physician is recruited to help, and the paramedic gives a quick snapshot of the incident. They snap some quick x-rays of the chest, draw blood and perform a 12-lead EKG. The physician locates a portable ultrasound machine to rapidly evaluate the chest and abdomen. His attention quickly turns to the signs of a very large abdominal aorta. It could not be felt on physical examination but is very apparent on the ultrasound image.

The physician prepares the patient: “Sir, it does not appear the accident hurt you, but instead it is a swelling of the big artery that goes through your abdomen, and it is probably leaking and causing your back pain. I’m going right away to talk to a surgeon, and it is possible they’ll need to take you right now to fix it.”

The patient moves quickly through that process, and his large aortic aneurysm is repaired using a new technique that threads a new lining into the middle of the aorta, avoiding the need for the big open surgery to repair the artery.

The man recovers well and is released home but told not to drive for a while. It appears his blood pressure had been out of control and likely very high for years, and that contributed to development of the aneurysm. While in the hospital, he is introduced to some physicians who offer to keep his blood pressure monitored but not “try to find problems.”

Case Discussion

High blood pressure over time places a strain on the walls of all arteries, including the aorta in both the chest and the abdomen. Eventually the layers composing the wall of the aorta can weaken, bulge and rupture.

In the abdomen an aortic aneurysm (AAA) occurs when the wall finally gives way and the patient begins to leak blood. The classic presentation includes pain in the abdomen, back or groin area. Syncope can occur, as with this patient. In some patients blood in the abdomen will cause a vagal reaction, with an inappropriately slow pulse. If the aneurysm ruptures quickly, the patient will lose a large blood volume, with sudden symptoms that include hypovolemic shock or cardiac arrest.

Editor’s note: For more on aortic dissections and aneurysms, see EMS World’s September CE article, www.emsworld.com/11602753.

James J. Augustine, MD, is an emergency physician and the director of clinical operations at EMP in Canton, OH. He serves on the clinical faculty in the Department of Emergency Medicine at Wright State University and as an EMS medical director for fire-based systems in Atlanta, GA; Naples, FL; and Dayton, OH. Contact him at jaugustine@emp.com.