Immediate Trauma CTs: Weighing the Risks and Benefits

May 13, 2013

Rapid CT programs may lead to faster diagnoses, but some say they may not be appropriate for all trauma patients and could unnecessarily increase radiation risk.

Rapid CT programs that take severely injured patients straight from an ambulance or helicopter to the scanner are gaining traction. It’s hard to quantify the success of programs involving critically ill patients, but the faster diagnoses and treatments suggest rapid CT programs are accomplishing what they set out to do.

Despite the faster diagnoses and reduced risk of leaving an injury undiagnosed, radiologists have voiced concern that the rapid CTs may not be appropriate for all trauma patients and could unnecessarily increase radiation risk.

Under  a  pilot program at a London hospital, a selected group of trauma patients arriving at King’s College Hospital by emergency transport immediately receive non-contrast head to pelvis CT studies.

Though radiologists are seeing the benefits, what about the increased exposure to radiation from automatic CTs? Will trauma patients benefit from a protocol that suggests immediate CTs? How will those patients be identified? Would localized CTs have provided the needed information? Such questions remain about whether the risks outweigh the benefits.

[[{"type":"media","view_mode":"media_crop","fid":"13650","attributes":{"alt":"Luis Rivas, MD","class":"media-image media-image-right","id":"media_crop_5613154586162","media_crop_h":"0","media_crop_image_style":"-1","media_crop_instance":"528","media_crop_rotate":"0","media_crop_scale_h":"0","media_crop_scale_w":"0","media_crop_w":"0","media_crop_x":"0","media_crop_y":"0","style":"float: right; margin: 5px;","title":"Luis Rivas, MD","typeof":"foaf:Image"}}]]“Our trauma surgeons wish they had a CT at the door, but some patients need to be stabilized first. In some patients it might not be a good idea,” said Luis A. Rivas, MD, associate professor of clinical radiology at the University of Miami Miller School of Medicine. Though not associated with the King’s College program, Rivas is familiar with rapid CT programs and remains concerned with protocols that would suggest CTs for a pre-selected group of patients. “Not all patients coming through the trauma center need to be scanned completely.”

Reducing mortality

Steps toward establishing the rapid CT program began in 2009 when King’s College Hospital began working to become a major trauma center. Thomas Best, MD, a consultant in intensive care for King’s College Hospital who chaired a task force charged with devising emergency radiology protocols for trauma patients, said the ultimate goal was to reduce mortality.

“This system, I hoped, would avoid a common and uncomfortable position to be in, that I believe many trauma clinicians recognize, which is to be 20 minutes into the trauma call, have done a FAST scan and plain films, given blood to sustain a blood pressure, recognize the patient is bleeding and unstable but be no closer to a diagnosis,” said Best.

“Now you are faced with the decision to go 'blind' to theaters for damage control surgery or at this delayed stage embark on a risky transfer to CT, which may indicate less invasive interventional radiology or only further delay definitive care.”

So the group hatched the idea to combine resuscitation and diagnosis, essentially allowing the trauma team to go mobile. But turning that idea on its head, Best said it was decided that the resuscitation bay would be brought to CT instead of the other way around. Other advanced UK trauma centers had instead inserted CT scanners into their resuscitation rooms.

Doctors and nurses step out of the room during the 10-second scan and results are available almost immediately. In addition to quick imaging results, the rapid scan means unstable high-risk patients aren’t being transferred to other hospital departments for scans. Patients are rapidly moved to other hospital departments after a review of CT results.

A protocol was developed to ensure trauma patients were not receiving unnecessary scans. “We realized it is possible to predict the need for CT on a substantial amount of patients simply from the pre-hospital information,” Best said.

Patients eligible to receive a rapid CT scan are intubated and ventilated blunt trauma patients arriving by emergency helicopter or ambulance. In addition, the hospital must have been warned at least 10 minutes ahead of time that a patient will be arriving. Code red patients, or those with potential for a major hemorrhage, also do not meet the hospital’s rapid scan criteria.

“Clearly if the major trauma consultant does feel a CT is not indicated after the patient has arrived then it can be immediately cancelled,” said Best, who noted eligible patients are a safe bet “where obvious benefit could also be gained.”

Even patients who are not transferred directly to CT - a small part of the hospital’s trauma services - appear to be benefitting from the program’s efficiency. The rapid CT program has improved working relationships among specialists and other personnel, improving patient transfer times across the board, Best said.

The program, which has been peer reviewed by the London Trauma System, is unique to King’s College Hospital, though Best said other medical centers have expressed interest in establishing some variation of the program. Doctors at the hospital have been advising other UK facilities working toward becoming established major trauma centers.

 Radiology protocol

A major trauma consultant is charged with alerting the radiographer and duty radiologist that a straight-to-CT patient will be arriving at the medical center. Following a review with an emergency medical service physician, the patient then heads directly to the scanner if found clinically appropriate.

 “They all require CT imaging and so I have no fear of unjustified exposure to radiation in these patients as the risk of delay from undiagnosed brain injury or bleeding clearly outweighs that of radiation dose in this clinical scenario,” said Dylan Lewis, MD, a consultant radiologist for King’s College Hospital. “We have a protocol to minimize the radiation dose with maximum information.”

Because the patient requirements for rapid CT are very specific, only 25 patients met the criteria between the program’s inception in April 2012 and April 2013, though during the same period the hospital also scanned hundreds of patients for conventional trauma CTs.

Lewis said that since only about two trauma patients a month are candidates for an immediate CT, the program has little impact on radiologist workload. Patients sent directly to CT would have needed the study anyway.

Not one size fits all

Though head to pelvis scans may be appropriate for most patients with serious trauma, particularly the group pinpointed in the pilot program, it’s tough to generalize all such patients will benefit.

Rivas said he sees the benefit in an immediate scan, particularly in cases where doctors could lose a critical hour trying to stabilize and diagnose a seriously injured patient.

“It sounds great and it probably works well, but it might not work for every patient. Right now the degree radiology has been used in trauma and the ER has just exploded in recent years. They really rely on radiology reports to see how they will proceed,” Rivas said, noting that his hospital performs head to toe CTs on trauma patients when deemed necessary.

Doctors may be less concerned about radiation and more concerned about missing a diagnosis, Rivas said. “There’s always a concern [of radiation] especially with women and children, but we have to take into account the benefits.”

“The advantage of doing the entire body is that you can do it in a few seconds. The amount of information that is there is tremendous and it can be very beneficial to patients. But if you have a more structured protocol - if you only do the brain without the chest or abdomen - you are significantly reducing the amount of radiation.”           

[[{"type":"media","view_mode":"media_crop","fid":"13651","attributes":{"alt":"Elliot Fishman, MD","class":"media-image media-image-right","id":"media_crop_8943290681954","media_crop_h":"0","media_crop_image_style":"-1","media_crop_instance":"529","media_crop_rotate":"0","media_crop_scale_h":"0","media_crop_scale_w":"0","media_crop_w":"0","media_crop_x":"0","media_crop_y":"0","style":"float: right; margin: 5px;","title":"Elliot Fishman, MD - credit Keith Weller/Johns Hopkins Medicine","typeof":"foaf:Image"}}]]Elliot Fishman, MD, professor of radiology, surgery and oncology at Johns Hopkins Hospital, believes clinical judgment should be brought in before a trauma patient is sent for a CT that encompasses multiple studies. He said the technology exists to completely scan patients from the top of the head to the pelvis or even the lower extremities.

“The key thing is should we do it?” he said. “I think the answer is sometimes yes, but most of the time no.”

As an example, he noted a complete scan would be appropriate for a trauma patient involved in a car crash who has multiple points of injury. In this case, one head to pelvis or head to toe study could answer many questions. With more localized trauma, specific CTs may make more sense. The mechanism of injury, he said, is key in deciding how to proceed with scans in cases of trauma.

“As we try to be more careful with radiation we need to try to consider protocol with patients. It can’t be a one-size-fits-all process. I think clinical judgment needs to be brought in. If we’re just doing really every trauma patient that comes to the ER door, I think we could be doing a disservice to patients,” Fishman said.

“If it’s the right patient, it’s the right thing to do, but it’s not for everybody. As a routine rule it’s concerning to me. The second you have one rule that applies to every situation, you realize that’s probably not a good idea.”

Though Fishman called radiation “more potential harm than real” harm, he said it is still a concern and should cause doctors to stop and consider which specific studies are needed.

“At the end, radiation is the most concerning to me,” he said. “You could be giving a radiation dose when there is no reason to do the study. You want to make sure every study is indicated and not just a protocol.”

Fishman didn’t discount the use of CTs, whether localized or a larger area of the body, but emphasized more complete studies should only be performed on trauma patients with injuries to several areas of the body following a physician consultation. He said there’s no question a stabilized trauma patient with multiple gunshot wounds could benefit from an immediate CT.

“They should go right to the scanner if it’s appropriate, but in the big scheme of things there is a small number of patients we would do that for,” he said.

Best said radiation risk is carefully weighed. It’s a driving reason that a major trauma consultant and radiologist are charged with making rapid scan decisions. A review of straight-to-CT patients determined that all would have required CT even if they had arrived at the hospital as conventional trauma patients.

“We take the risk of radiation exposure very seriously,” he said, “However, care also needs to be taken that a relatively low risk of radiation does not get in the way of a real risk of missing life threatening injury.”