All posts by TheTraumaPro

Liquid Plasma vs FFP: Definitions

I’ll spend the next few days discussing plasma. This is an important component of any trauma center’s massive transfusion protocol (MTP). Coagulopathy is the enemy of any seriously injured patient, and this product is used to attempt to fix that problem.

And now there are two flavors available: liquid plasma and fresh frozen plasma. But there is often confusion when discussing these products, especially when there are really three flavors! Let’s review what they are exactly, how they are similar, and how they differ.

Fresh frozen plasma (FFP)
This is plasma that is separated from donated whole blood. It is generally frozen within 8 hours, and is called FFP. However, in some cases it may not be frozen for a few more hours (not to exceed 24 hours total) and in that case, is called FP24 or FP. It is functionally identical to FFP. But note that the first “F” is missing. Since it has gone beyond the 8 hour mark, it is no longer considered “fresh.” To be useful in your MTP, it must be thawed, and this takes 20-40 minutes, depending on technique.

Thawed plasma
Take a frozen unit of FFP or FP, thaw, and keep it in the refrigerator. Readily available, right? However, the clock begins ticking until this unit expires after 5 days. Many hospital blood banks keep this product available for the massive transfusion protocol, especially if other hospital services are busy enough to use it if it is getting close to expiration. Waste is bad, and expensive!

Liquid plasma (never frozen)
This is prepared by taking the plasma that was separated from the donated blood and putting it in the refrigerator, not the freezer. It’s shelf life is that of the unit of whole blood it was taken from (21 days), plus another 5, for a total of 26 days. This product used to be a rarity, but is becoming more common because of its longer shelf life compared to thawed plasma.

Finally, a word on plasma compatibility. ABO compatibility is still a concern, but Rh is not. There are no red cells in the plasma to carry any of the antigens. However, plasma is loaded with A and/or B antibodies based on the donor’s blood type. So the compatibility chart is reversed compared to what you are accustomed to when giving red cells.

Remember, you are delivering antibodies with plasma and not antigens. So a Type A donor will have only Type B antibodies floating around in their plasma. This makes it incompatible with people with blood types B or AB.

Type O red cells are the universal donor type because the cells have no antigens on the surface. Since Type AB donors have both antigens on their red cells, they have no antibodies in their plasma. This makes AB plasma is the universal donor type. Weird, huh? Here’s a compatibility chart for plasma.

Next time, I’ll discuss the virtues of the various types of plasma when used for massive transfusion in trauma.

Vascular Trauma Resources At Pediatric Trauma Centers

There are two types of pediatric trauma centers: freestanding and combined. These adjectives refer to whether an adult trauma center is directly associated with the pediatric one. Over the years, I have come to appreciate that there may be substantial resource and experience differences between the two.

Trauma surgeons at freestanding centers are usually pediatric surgeons. They have managed trauma cases during their surgical residency and pediatric surgical fellowship, but usually have not taken a trauma fellowship. Their experience with complex trauma and advanced concepts like damage control surgery generally comes from their training and on the job experience. Surgeons at combined centers may be pediatric trained, or may be adult surgeons with pediatric experience. The adult surgeons are generally well-versed in advanced trauma concepts, and the pediatric surgeons can take advantage of the adult surgeons’ expertise in advanced trauma cases.

Freestanding pediatric centers may have fewer resources in some key areas, such as fellowship trained specialists in vascular surgery, GI endoscopy, and interventional radiology. A recent study accepted for publication from the University of Arkansas examines differences in surgeon practice patterns and resource availability at freestanding vs combined centers.

Two surveys were sent to 85 pediatric trauma centers around the US. Roughly half were Level I, and half were freestanding. One was sent to 414 pediatric surgeons at those centers inquiring about practice patterns, and the other was sent to the trauma medical directors of each center asking about their resources.

Here are the factoids:

  • 50 of the 85 trauma centers responded, as did 176 of the 414 surgeons. 48% of trauma medical directors responded. These are reasonable response rates for questionnaires.
  • Adult surgeons covered pediatric trauma at 6% of Level I centers, and 33% of Level II
  • During pediatric surgical fellowship, 56% participated in management of vascular trauma, 25% was managed by vascular surgeons, and 19% had no experience
  • At 23% of freestanding centers, vascular surgeons were not always available, and a vascular surgeon was not listed on the call schedule 38% of the time
  • 27% of freestanding facilities indicated that endovascular and stent capabilities were not available, and 18% did not have interventional radiologists (IR) available within 30 minutes
  • All combined centers had vascular and endovascular capabilities, and IR was available within 30 minutes 92% of the time

Bottom line: This is an intriguing paper that looks at a few of the disparities between freestanding and combined pediatric trauma centers. Obviously, it is hampered by the survey format, but does provide some interesting information. The focus was on vascular resources, and shows several of the major differences between the two types of centers.

Fortunately, vascular trauma is relatively rare in the pediatric age group. But it is possible that a child presenting to a freestanding pediatric trauma center may be managed by a pediatric surgeon with little vascular experience, and assistance from a fellowship trained vascular surgeon and/or interventional radiologist may be unavailable.

This paper provides important information regarding resource disparities in pediatric trauma care. Ideally, this should be reviewed and remedied as the Resources for Optimal Care of the Injured Patient (Orange Book) evolves over the coming years.

Reference: Pediatric Vascular Trauma Practice Patterns and Resource Availability: A Survey of ACS-Designated Pediatric Trauma Centers. J Trauma, accepted for publication Jan 12, 2018.

The Final X-Ray In Damage Control Surgery

Damage control surgery for trauma is over 20 years old, yet we continue to find ways to refine it and make it better. Many lives have been saved over the years, but we’ve also discovered new questions. How soon should the patient go back for definitive closure? What is the optimal closure technique? What if it still won’t close?

One other troublesome issue surfaced as well. We discovered that it is entirely possible to leave things behind. Retained foreign bodies are the bane of any surgeon, and many, many systems are in place to avoid them. However, many of these processes are not possible in emergent trauma surgery. Preop instrument counts cannot be done. Handfuls of uncounted sponges may be packed into the wound.

I was only able to find one paper describing how often things are left behind in damage control surgery (see reference below), and it was uncommon in this single center study (3 cases out of about 2500 patients). However, it can be catastrophic, causing sepsis, physical damage to adjacent organs, and the risk of performing an additional operation in a sick trauma patient.

So what can we do to reduce the risk, hopefully to zero? Here are my  recommendations:

  • For busy centers that do frequent laparotomy or thoracotomy for trauma and have packs open and ready, pre-count all instruments and document it
  • Pre-count a set number of laparotomy pads into the packs
  • Use only items that are radiopaque or have a marker embedded in them. This includes surgical towels, too!
  • Implement a damage control closure x-ray policy. When the patient returns to OR and the surgeons are ready to begin the final closure, obtain an x-ray of the entire area that was operated upon. This must be performed and read before the closure is complete so that any identified retained objects can be removed.

Tomorrow, a sample damage control closure x-ray.

Related post:

Reference: Retained foreign bodies after emergent trauma surgery: incidence after 2526 cavitary explorations. Am Surg 73(10):1031-1034, 2007.

The Final X-Ray In Damage Control Surgery

Damage control surgery for trauma is over 20 years old, yet we continue to find ways to refine it and make it better. Many lives have been saved over the years, but we’ve also discovered new questions. How soon should the patient go back for definitive closure? What is the optimal closure technique? What if it still won’t close?

One other troublesome issue surfaced as well. We discovered that it is entirely possible to leave things behind. Retained foreign bodies are the bane of any surgeon, and many, many systems are in place to avoid them. However, many of these processes are not possible in emergent trauma surgery. Preop instrument counts cannot be done. Handfuls of uncounted sponges may be packed into the wound.

I was only able to find one paper describing how often things are left behind in damage control surgery (see reference below), and it was uncommon in this single center study (3 cases out of about 2500 patients). However, it can be catastrophic, causing sepsis, physical damage to adjacent organs, and the risk of performing an additional operation in a sick trauma patient.

So what can we do to reduce the risk, hopefully to zero? Here are my  recommendations:

  • For busy centers that do frequent laparotomy or thoracotomy for trauma and have packs open and ready, pre-count all instruments and document it
  • Pre-count a set number of laparotomy pads into the packs
  • Use only items that are radiopaque or have a marker embedded in them. This includes surgical towels, too!
  • Implement a damage control closure x-ray policy. When the patient returns to OR and the surgeons are ready to begin the final closure, obtain an x-ray of the entire area that was operated upon. This must be performed and read before the closure is complete so that any identified retained objects can be removed.

Tomorrow, a sample damage control closure x-ray.

Related post:

Reference: Retained foreign bodies after emergent trauma surgery: incidence after 2526 cavitary explorations. Am Surg 73(10):1031-1034, 2007.

Why People Don’t Change Their Minds Despite The Data

Has this happened to you?

Your (emergency physician / neurosurgeon / orthopaedic surgeon) colleague wants to (get rib detail xrays / administer steroids / wait a few days before doing a femur ORIF). You question it based on your interpretation of the literature. You even provide a stack of papers to them to prove your point. Do they buy it? Even in the presence of randomized, double-blinded, placebo-controlled studies with thousands of patients (good luck finding those)?

The answer is generally NO! Why not? It’s science. It’s objective data. WTF?

Sociologists and psychologists have shown that there is a concept that they call the Backfire Effect. Essentially, once you come to believe something, you do your best to protect it from harm. You become more skeptical of facts that refute your beliefs, and less skeptical of the items that support them. Having one’s beliefs challenged, even with objective and authoritative data, causes us to hold them even more deeply. There are plenty of examples of this in everyday life. The absence of weapons of mass destruction in Iraq. The number of shooters in the JFK assassination. President Obama’s citizenship.

Bottom line: It’s human nature to try to pick apart a scientific article that challenges your biases, looking for every possible fault. It’s the Backfire Effect. Be aware of this built in flaw (protective mechanism?) in our psyche. And always ask yourself, “what if?” Look at the issue through the eyes of someone not familiar with the concepts. If someone challenges your beliefs, welcome it! Be skeptical of both them AND yourself. You might just learn something new!