All posts by The Trauma Pro

Complications

EAST 2017 #11: Use of Incompatible (Type A) Plasma For Massive Transfusion

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Type AB plasma is considered “universal donor” plasma, as it contains no antibodies to red cells with either A or B antigens on their surface. Unfortunately, only about 4% of the US population have this blood type and can provide the product. Due to this shortage, some trauma centers have decided to use Type A plasma initially for massive transfusion, and switch to type specific plasma once patient blood has been typed and screened.

This works, since only about 13% of the population have red cells with B antigens on the surface. But are there any adverse effects in those patients who receive potentially incompatible plasma? The EAST Multicenter Study group performed a retrospective study using trauma registry and blood bank data from 5 trauma centers. They looked at adult patients who received plasma as part of the massive transfusion protocol (MTP) over a 4+ year period. Incompatible type A plasma transfusion was defined to occur if a patient had either Type B or AB blood.

Here are the factoids:

  • There were a total of 1212 patients in the study; 93% were compatible and 7% were incompatible type A initial transfusions
  • The usual trauma demographics were seen (young, male) and the average ISS was 25 (they triggered an MTP, remember?)
  • By chance, the incompatible group had a slightly higher ISS (29) and penetrating injury rate (45% vs 33%)
  • The incompatible group received significantly more plasma during the first 4 hours and during the first day
  • There was no difference in mortality sepsis, ARDS, thromboembolic events, or renal failure
  • Regression analysis showed that incompatible plasma was not a predictor of mortality or morbidity
  • There was one hemolytic reaction and one occurrence of TRALI, both in the compatible group

Bottom line: This is the largest study around on the topic, and it does not show any significant problems (at least the ones that were studied) with giving incompatible plasma in acute trauma. How can this be, you ask? Remember, only the first one or two units (the first MTP pack) is potentially incompatible. Hopefully, by the time the second pack is delivered, the blood has been typed. And these patients are potentially receiving multiple units of typed plasma after the initial transfusion which dilutes the incompatible, and multiple transfusions overall which may blunt their immune response. 

This is an important paper that all centers should consider as they update their massive transfusion protocols!

Questions and comments for the authors/presenters:

  1. The abstract states that 5 centers participated, but the tables only list 4. Please explain this.
  2. It is not stated explicitly whether all centers used type A plasma initially. Is this the case?
  3. This is important work! Have any other centers converted to initial use of type A plasma?

Click here to go the the EAST 2017 page to see comments on other abstracts.

Related posts:

Reference: Use of incompatible type A plasma transfusion in patients requiring massive transfusion protocol: outcomes of an EAST multicenter study. Paper #16, EAST 2017.

Anatomy, Procedures, Thorax

EAST 2017 #10: A Simple Way To Predict Complications After Rib Fracture?

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Rib fractures are a common injury, and a very common cause of morbidity. Every time I admit an elderly patient with rib fractures, I debate whether they should go to the ICU or a ward bed. Could there be a more objective way of determining the likelihood of complications, aggressiveness of treatment, and admission unit?

A group at West Virginia University implemented a rib fracture pathway in 2009, and have been collecting data on patients ever since. It was based on the measurement of forced vital capacity (FVC) on admission. This is the total amount of air that can be exhaled during a forced breath.

The authors subdivided their patients into two groups based on the total volume exhaled (<1.5L, and >1.5L). They retrospectively reviewed 6 years of data, looking at specific injuries, complications, and unexpected transfer to ICU. They hypothesized that patients in the highest FVC group would have fewer complications.

Here are the factoids:

  • There was a nearly even split in groups, with 678 patients who had FVC > 1.5L, and 682 with FVC < 1.5
  • There were significantly fewer complications and pneumonia, as well as fewer readmissions in the FVC > 1.5 group
  • Higher FVC was not associated with fewer unexpected transfers to ICU
  • Length of stay was half as long (4d vs 8d) in the high FVC group, but no p value was provided
  • The authors conclude that patients with FVC much greater than 1.5 are at lower risk for complications regardless of the number of fractures (???!)
  • They even suggest that patients with FVC > 1.5 could be discharged from the ED rather than be admitted (!)

Bottom line: Well, it started out good! The abstract showed that the high FVC patients had fewer complications and readmissions. And the length of stay was shorter, although significance was not noted. But the jump to correlating complication risk with number of fractures was not addressed in the abstract. And I can’t quite grasp the leap to suggesting possible discharge from the ED. 

FVC may be an inexpensive and simple test to administer in new rib fracture patients. But it’s ability to predict who goes to ICU and who goes home from the ED was not really identified in the study. 

Questions and comments for the authors/presenters:

  1. A minor point, but the upper limit was defined as > 1.5L in some parts of the abstract, and > 1.5L in  others. Small point, but keep it clean. Make sure all the greater than, less than, and equals signs are consistent.
  2. Was the shorter length of stay significantly different between the groups?
  3. Did you do any stratification by age?
  4. How did you make the conclusion that patients could be sent home from the ED?
  5. And did you do any correlations with your FVC data and the number of fractures? It’s not in the abstract.

Click here to go the the EAST 2017 page to see comments on other abstracts.

Related post:

Reference: Is an FVC of 1.5 adequate for predicting respiratory sufficiency in rib fractures? Paper #4, EAST 2017.

Trauma Systems

EAST 2017 #9: Geographic Location and Fatal Car Crashes

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Trauma resources (centers and helicopter services) are not geographically evenly distributed across the US. The East and West coasts are saturated with resources, maybe overly so. At the other extreme, some northern states (Alaska and the north central US) have very few trauma resources, and injured patients may have to travel several hundreds of miles to get definitive trauma care.

The group at the University of Pittsburgh looked at trauma resource distribution across the state of Pennsylvania, and matched that with geographical data from fatal car crashes over a two  year period. They used some special statistical tools to analyze this type of data, and reported their findings in a format that will be unfamiliar to many: fatalities per 100 million vehicle miles traveled (VMT).

Here are the factoids:

  • 863 fatal crashes occurred during the study period, killing 884 people
  • The median fatality rate for the state was .187 per 100 million VMT
  • Fatality hotspots became very apparent in areas farther from trauma system resources (TSR) (see map below, dark areas are bad)
  • The fatality rate increased significantly by 0.01 per 100 million VMT for each mile farther away from any TSR.
  • If just 2 helicopters had been relocated from trauma centers to high fatality regions, the overall fatality rate could have been reduced by 12%, in theory

Bottom line: This novel way of looking at injury data confirms what we all knew or suspected: injuries occurring farther away from trauma resources may lead to higher mortality and disability. And knowledge is power. If we can see it, we can do something about it. This type of analysis should be done on regional, state, and national levels to help us better serve our patients.

Questions and comments for the authors/presenters:

  1. Be able to describe your statistics simply
  2. How did you deal with data from the border areas of the state? Did you include trauma resources from adjacent states in your analysis?
  3. You mention “county-level” factors in adjusting mortality rates for distance. What were these?
  4. This is a novel way of approaching system planning. Nice job!

Click here to go the the EAST 2017 page to see comments on other abstracts.

Related post:

Reference: Distance matters: effect of geographic trauma system resource organization on fatal motor vehicle collisions. Paper #3, EAST 2017.

Complications, Head

EAST 2017 #8: When Is “Mild TBI” Not So Mild?

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Traumatic brain injury (TBI) is very common, with the majority falling into the “mild” category. This is usually defined as patients with injury to the head and a GCS of 13-15. These uncomplicated patients are frequently discharged from the emergency department, or undergo only a brief evaluation if admitted for other reasons.

The group at Shock Trauma focused on a less appreciated subset of mild TBI patients, those whose condition is a little more complicated. Specifically, these are patients with GCS 13-14 with positive findings on head CT leading to a calculated abbreviated injury score (head) of > 2, and some persistence of their symptoms while in the hospital. At many hospitals (including my own), these patients receive an inpatient TBI evaluation. But if they pass this initial screening, they are not consistently referred for any outpatient TBI followup.

Are these mild, complicated TBI patients (mcTBI) unique? Do they behave the same as the uncomplicated ones? The research group performed a prospective study on patients who sustained an mcTBI over a 4 month period.  They excluded patients with mental illness, dementia, and non-English speaking and homeless patients. They tried to contact patients up to three times after discharge to administer several standard tests and determine if they had any specific residual symptoms.

Here are the factoids:

  • Of the 142 patients with mcTBI during the study period, there was substantial attrition over time, with only 25 remaining at 6 months and 10 at one year
  • 64% of patients who responded at 6 months remained symptomatic. Depression, dizziness, and a feeling of impaired health were common.
  • 80% of patients still described symptoms at one year. The same complaints were most common, and some required changes in activities of daily living or assistive devices.

Bottom line: Although small and fraught with the usual problems in long-term tracking of urban trauma patients, this study is eye-opening. We too often dismiss “mild TBI” and being almost nothing, even in patients with positive findings on head CT. This work suggests that we are underestimating the needs of those patients. The authors used this data to design longer-term care processes for this subset of patients. Other centers should follow suit to make sure these patients’ post-injury needs are better met.

Questions and comments for the authors/presenters:

  • Describe the possible biases that patient selection and attrition may have had on the study
  • What type of TBI screening do you use in the hospital?
  • Given that a number of assessments were administered over the phone, I look forward to hearing some of the other details not listed in the abstract
  • Was there any correlation between specific CT findings and later symptoms?
  • Provide details of your long-term care programs for these patients
  • I enjoyed this thought provoking abstract!

Click here to go the the EAST 2017 page to see comments on other abstracts.

Related posts:

Reference: Mild TBI is not ‘mild’… survivors tell their complicated stories. Quick Shot #3, EAST 2017.

Procedures, Thorax

EAST 2017 #7: Pigtail vs Chest Tube – Does Size Matter?

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I’ve been somewhat old school when it comes to chest tubes. Unlike some, I don’t believe that you have any control of where a chest tube goes if you are placing it in a closed chest. Only in the OR with an open one. And I’ve got plenty of x-rays to prove it.

And I used to think that chest tube size mattered when dealing with hemothorax. In theory, you need a big tube to get clots out, right?

Well, maybe not! The trauma group at the University of Arizona Tucson has previously done work on using 14 French pigtail catheters in lieu of a full-size tube. They will be presenting their extended experience with this concept at EAST 2017.

They have maintained a prospectively collected database of information on trauma patients with chest tubes for many years. This study focused only on those who had blood in their chest, either hemothorax (HTX) or hemopneumothorax (HPTX). They also looked at trends in their selection of chest drain tubes.

Here are the factoids:

  • Nearly 500 patients were treated with a tube for HTX or HPTX during the 7 year study period, 2/3 with a chest tube and 1/3 with a pigtail
  • Pigtails had more fluid drain initially (430cc vs 300cc, significant), and 1 less treatment day (4 vs 5, also significant)
  • Failure rate and insertion-related complications were the same (about 22% and 6%, respectively)
  • The group found that their use of pigtails steadily and significantly increased over the years

Bottom line: I’m coming around. The literature does appear to be tilting toward smaller tubes, and this longer-term study helps confirm that. How can this be? Although this is speculation on my part, it probably has to do with the fact that any size tube will drain liquid blood. And probably no size of tube will successfully get all the clot out. 

And certainly, smaller tubes are much better tolerated and do not require the degree of sedation that a mega-tube does. The authors suggest that a multi-center trial should be carried out to confirm this. For my part, I’m going to review the literature we have to date and consider modifying my own chest tube policy (see links below).

Questions and comments for the authors/presenters:

  • Where did you typically insert the pigtails? Anterior chest or classic chest tube position? Was it consistent?
  • Was/is the selection of tube type an attending surgeon specific choice, or did you implement a policy to direct them?
  • Did patient injury pattern or body habitus have any part in tube selection?
  • What about removal failures? That is, how many had to have a tube replaced, and how many went on to require VATS or other surgical procedure for drainage?
  • I enjoyed this provocative paper!

Click here to go the the EAST 2017 page to see comments on other abstracts.

Related posts:

Reference: A prospective study of 7-year experience of using percutaneous 14-French pigtail catheter for traumatic hemothorax at a Level I trauma – size still does not matter. Quick Shot #4, EAST 2017.