All posts by The Trauma Pro

Head

Everything You Wanted To Know About: Cranial Bone Flaps

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Patients with severe TBI frequently undergo surgical procedures to remove clot or decompress the brain. Most of the time, they undergo a craniotomy, in which a bone flap is raised temporarily and then replaced at the end of the procedure.

But in decompressive surgery, the bone flap cannot be replaced because doing so may increase intracranial pressure. What to do with it?

There are four options:

  1. The piece of bone can buried in the subcutaneous tissue of the abdominal wall. The advantage is that it can’t get lost. Cosmetically, it looks odd, but so does having a bone flap missing from the side of your head. And this technique can’t be used as easily if the patient has had prior abdominal surgery.

2. Some centers have buried the flap in the subgaleal tissues of the scalp on the opposite side of the skull. The few papers on this technique demonstrated a low infection rate. The advantage is that only one surgical field is necessary at the time the flap is replaced. However, the cosmetic disadvantage before the flap is replaced is much more pronounced.

3. Most commonly, the flap is frozen and “banked” for later replacement. There are reports of some mineral loss from the flap after replacement, and occasional infection. And occasionally the entire piece is misplaced. Another disadvantage is that if the patient moves away or presents to another hospital for flap replacement, the logistics of transferring a frozen piece of bone are very challenging.

4. Some centers just throw the bone flap away. This necessitates replacing it with some other material like metal or plastic. This tends to be more complicated and expensive, since the replacement needs to be sculpted to fit the existing gap.

So which flap management technique is best? Unfortunately, we don’t know yet, and probably never will. Your neurosurgeons will have their favorite technique, and that will ultimately be the option of choice.

Reference: Bone flap management in neurosurgery. Rev Neuroscience 17(2):133-137, 2009.

Guidelines

Best Practice: The MTP Coordinator

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Every trauma center has a massive transfusion protocol (MTP). But every trauma center also does it entirely differently. Ideally, an MTP is designed with the resources available at the hospital in mind. These may include whole blood, the use of O- vs. O+ blood, the number of units of each product per cooler, the different products in different coolers, and personnel available to move those coolers to the correct locations.

In my experience, one of the areas with the greatest variability is the person or persons who are actually directing the blood resuscitation, hanging the units, and doing the paperwork. Frequently, this is split across several people. In the ED, the surgeon is usually directing it. However, nurses typically hang the products and do the paperwork.

Often, though, the surgeon may be up to their elbows in a resuscitative thoracotomy and may be unable to direct their full attention to figuring out if more products are needed. In the OR, the anesthesiologist can frequently take over this task while the surgeon is busy in a body cavity. But sometimes, the resuscitation needs may overwhelm even their ability to concentrate on the MTP.

The Solution

The solution to this problem borrows from the team leader concept in trauma resuscitation. It is best if the team leader has minimal clinical responsibilities during the resuscitation. Once they move in and touch the patient, their area of attention collapses to that one spot, and they cannot fully concentrate on all of the big-picture issues going on in the room.

This is where the MTP coordinator comes in. This is a dedicated person who only has one job: to deal with the MTP.  They have no other responsibilities in the room.

Here is a list of tasks that they can offload from the other nurses and physicians in the ED/OR:

  • Call for the next cooler to be sent from the blood bank, taking into account the transit time
  • Ensure required labs are being sent for crossmatch and TEG/ROTEM, if used
  • Order and hang TXA on appropriate patients
  • Transfuse products in the appropriate order
  • Fill out all required transfusion records
  • Ensure 1:1:1 transfusion ratios
  • Regularly inform the surgeon of the current product counts
  • Order calcium and cryoprecipitate when appropriate, according to your protocol
  • Inform the blood bank when the patient moves to a new area (e.g. ED to OR) and follow along with the patient
  • As the resuscitation winds down, interpret TEG/ROTEM and modify transfused products as indicated
  • Notify the blood bank when the MTP is terminated
  • Ensure all final paperwork is complete

This seems like a lot! But we are normally asking numerous people in the trauma bay to do it. Assigning it to one person and one person only creates a much more reliable and efficient system.

Who should it be assigned to? Generally, not one of the usual ED nurses. This is a specialized position that requires additional training and practice. Some trauma programs have dedicated trauma nurses for trauma resuscitation, and they may be a good choice. However, they are frequently the only nurses assigned to resuscitations, and making them the MTP coordinator takes them off all other duties. This may not be practical.

In my opinion, the best candidate is an ICU nurse who has received training for this duty. Ideally, it would be the ICU nurse who would be receiving and taking care of that patient in the ICU if they survive. They will be very familiar with their patient once they arrive there.

If you have an MTP coordinator at your center, please take a moment to leave comments or suggestions below! Let us know how you do it.

Imaging

The Role Of Postop CT Scan In Penetrating Trauma

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CT scans are commonly used to aid the workup of patients with blunt trauma. They are occasionally useful in penetrating trauma, specifically when penetration into a body cavity is uncertain, and the patient has no hard signs that would send him or her immediately to the operating room.

Is there any role for CT in operative penetrating trauma, after the patient has already been to the OR? The dogma has always been that the eyeballs of the surgeon in the OR are better than any other imaging modality. Really? The surgical group at San Francisco General addressed this question by retrospectively reviewing 6 years of their operative penetrating injury registry data. They were interested in finding how many occult injuries (seen with CT but not by the surgeon) were found on a postop CT. A total of 225 patients who underwent operative management of penetrating abdomen or chest injury were included. Here are the factoids:

  • Only 110 patients had a postop CT scan; 73 had scans within the first 24 hours, the other 37 were scanned later
  • The rationale for early scan was to investigate retroperitoneal injury in half of patients, but frequently no indication was given (41%)
  • The rationale for late scan was for workup of ileus in one-third or for evaluation of new or unexpected clinical problems
  • Occult injuries were found in about half of early CT patients (52%) and 22% of late CT patients
  • The most common occult injuries were fractures, GU issues, regraded solid organ injury, and unrecognized vascular injuries
  • Ten patients had management changes, including:
    • Interventional radiology for four injuries with extravasation
    • Operation for orthopedic or GU injury in seven patients
    • One patient underwent surgery for an unstable spine fracture

Bottom line: There appears to be a significant benefit to sending some penetrating injury patients to CT in the early postop period. Specifically, those with injury to the retroperitoneum, deep into the liver, near the spine, or with multiple and complicated injuries would benefit. Simple stabs and gunshots that stay away from these areas/structures probably do not need follow-up imaging. 

Reference: Routine computed tomography after recent operative exploration for penetrating trauma: What injuries do we miss? J Trauma 83(4):575-578, 2017.

Pelvis

Pelvic Fracture Intervention And Venous Thromboembolism Risk

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Earlier this year, I wrote a series of posts on the two commonly used pelvic fracture interventions: preperitoneal packing (PPP) and angioembolization (AE). To sum up, both are equally effective in controlling hemorrhage, but the hospital costs for patients undergoing angioembolization are significantly less. This is probably because there is no need to perform repeated operations to insert and remove the preperitoneal packs when angiography is used.

But what about venous thromboembolism risk? Patients with pelvic fractures are already at high risk for it. Couldn’t the increase in pressure on the pelvic veins or the use of thrombogenic materials increase the risk? Authors from several well-known trauma centers collaborated to re-analyze data from the CLOTT study. This is another cute acronym for an extensive study, the Consortium of Leaders in the Study of Traumatic Thromboembolism. It looked at the incidence and risk factors for VTE in trauma patients. This analysis focused on VTE risk in patients with pelvic fractures, comparing those undergoing one of the two interventions with those who had neither.

Here are the factoids:

  • The original data were derived from a 17-center study conducted from 2018-2020; this study only included 1,387 patients who had pelvic fractures (as well as other injuries).
  • The primary outcome was the development of VTE during the hospitalization. DVT was detected using duplex ultrasound, and PE was detected by CT angiography. If pulmonary clots were seen without concomitant DVT, they were not considered to be of embolic origin.
  • For all comers, the overall incidence of VTE was 5.6%
  • Breaking them down by type, there were 2.7% PE, 2.7% DVT, and 1.9% pelvic thrombi (some patients had more than one event)
  • Chemical prophylaxis appeared to be very effective. If started within 24 hours, the incidence was 2.9% vs. 8.4%* if started later.
  • Missed doses did not appear to increase the incidence of VTE (about 5% for both groups)
  • Patients with PPP had a 9% incidence of VTE, pelvic angioembolization had 2.6%, and patients with ORIF had 16%. The incidence was 5.7% if no interventions at all were performed and 16% if more than one occurred.

Bottom line: There are a lot of tidbits in this paper. Most importantly, the use of PPP or AA does not significantly increase VTE risk. Interestingly, ORIF of the pelvis increases it. It’s not clear whether this is due to the procedure itself or is just a surrogate for the severity of pelvic injury. Multivariate analysis suggests that this is not a significant risk factor.

The finding that early chemoprophylaxis reduced VTE incidence to only 3% is very interesting. All too often, prophylaxis is delayed due to solid organ or head injuries. If it can be started safely in such patients, it should be to reduce the occurrence of this complication. One of the banes of management of major trauma is the potential need for repeated surgical procedures, which leads to a phenomenon known as “prophylaxis interruptus.” Thankfully, this study did not find that this increased VTE risk, although it did not stratify by how many doses were missed.

So put your mind at ease about increasing the risk of VTE risk by using procedures to decrease bleeding through mechanical means. But do remember to begin chemoprophylaxis soon and you safely can.

Reference: Does preperitoneal packing increase venous thromboembolism risk among trauma patients? A prospective multicenter analysis across 17 level I trauma centers. Journal of Trauma and Acute Care Surgery 97(5):p 791-798, November 2024.

Prehospital

What Is The Safest Extrication Method From A Car Crash?

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Today’s post is directed to all those prehospital trauma professionals out there.

Car crashes account for a huge number of injuries worldwide. About 40% of people involved are trapped in the vehicle. And unfortunately, entrapped individuals are much more likely to die.

There are four basic groups (and their category in parentheses) of trapped car occupants:

  • those who can self-extricate or extricate with minimal assistance (self-extrication)
  • individuals who cannot self-extricate due to pain or their psychological response to the event but can extricate with assistance (assisted extrication)
  • people who are advised or choose not to self-extricate due to concern for exacerbating an injury, primarily spine (medically trapped)
  • those who are physically trapped by the wreckage who require disentanglement (disentanglement and rescue)

Prehospital providers have several choices to help extricate patients in the second and third categories: encourage self-extrication, rapid extrication without tools, or traditional extrication, where the vehicle is cut away to allow egress. The fourth category always requires tools for extrication.

Although rescue services try to minimize or mitigate unnecessary patient movement, stuff happens. Large and forceful movement is considered high risk, but smaller movements do occur. This is of particular concern in patients who might have a spine injury.

There have been several recent papers suggesting there might be greater benefits to self-extrication. A group of authors in the UK and South Africa designed a biomechanical study to test these extrication methods in healthy volunteers.

The authors wanted to determine exactly how much movement occurred using the various extrication techniques. The volunteers were fitted with an Inertial Measurement Unit, which measures the orientation of the head, neck, torso, and sacrum in real-time.  The IMU can detect even minimal changes in the orientation of the body. The volunteers were placed in a standard 5-door hatchback sedans that were prepared for each type of extrication, as seen above.

Here are the factoids:

  • A total of 230 extrications were performed for analysis
  • The smallest amount of maximal and total movement of body segments was seen in the self-extrication group
  • The greatest amount of movement was found in the rapid extrication group, with 4x to 5x the movement in the self-extrication group
  • The difference in body movement between the self-extrication group and all others was significant
  • In general, movement increased as extrication techniques progressed from roof removal to B post removal to rapid extrication

The authors concluded that self-extrication resulted in the smallest amount of movement and the fastest extrication time and should be the preferred technique.

Bottom line: This is the first study that specifically evaluated spinal movement occurring with commonly used extrication techniques. Other similar studies have used various measurement techniques, none of which are as precise as this. One potential weakness with this one is that it used healthy volunteers. But obviously, it is not practical to attempt anything like this with real, injured patients. 

Since we know that patients trapped in cars are more likely to die, time is of the essence. This study shows that self-extrication is both fast and safe with respect to spinal movement. The information will assist our prehospital colleagues in making the best decisions possible when faced with patients trapped in their cars.

Reference: Assessing spinal movement during four extrication methods: a biomechanical study using healthy volunteers. Scand J Trauma  open access 30: article 7, 2022.