Tag Archives: pediatric

MTP Activation Criteria For Pediatric Patients

Early resuscitation, particularly with blood products in patients with hemorrhage, is literally a lifesaver.  As each minute ticks by, survival slowly diminishes. To facilitate this, massive transfusion protocols (MTP) have been designed to rapidly deliver sizable quantities of blood products to the trauma resuscitation bay.

One of the recurring issues I see at trauma centers is the lack of a reliable way of activating the MTP. Many centers publish what I consider “psychic criteria.” These promote criteria that involve the amount of blood loss over four or twenty-four hours. Who even knows?

Delays in activating the MTP frequently occur because no one thinks about it when a critically injured patient arrives. All of the trauma professionals are busy with the patient and are rudely surprised when they ask for the first unit of blood.

Objective MTP activation criteria have been developed and are well-supported by the literature. The ABC score and the shock index are two of the more common methods. Both are based on observations made upon patient arrival (and possibly before if a prehospital report is received).

The ABC score uses four criteria:

  • Heart rate > 120
  • Systolic blood pressure < 90
  • FAST positive
  • Penetrating mechanism

If any two of these are present, there is a 50% chance that massive transfusion is warranted.

The Shock Index (SI) uses the initial vital signs to perform a quick and dirty calculation by dividing the heart rate by the systolic blood pressure.  A score greater than or equal to one predicts at least a 2x higher need for blood. Of the two, SI is more easily calculated and gives a marginally more accurate result.

But what about children? The ABC score was evaluated in pediatric patients and was found to be much less sensitive than in adults. Combining the ABC score with an age-adjusted Shock Index improved the accuracy only slightly. This was named the ABC-S score.

Several adult and pediatric trauma centers in the Denver area collaborated to test a new score using the ABC-S score in combination with serum lactate and base deficit. This was termed the ABC-D score. Clever.

Here are the factoids:

  • A retrospective review of patients aged 1-18 from a single trauma registry who had received a blood transfusion during their initial care
  • The study included 211 children, of whom 66 required massive transfusion
  • The three methods listed above were compared, and the ABC-D score was found to be the most predictive of MTP
  • ABC-D was 77% sensitive and 79% specific
  • The authors showed that the accuracy and balance between sensitivity and specificity improved for each point increase in the ABC-D score.
  • They concluded that ABC-D may be a useful tool to expedite the delivery of blood products during a trauma resuscitation.

Bottom line: Hmm. The system that they developed and the analysis of their experience appears to be sound. But unfortunately, it fails the practicality test. Here’s the sticking point. How long does it take to obtain that initial blood specimen, send it to your lab, and then return stat results to your trauma bay? Once you receive the results, you then activate the MTP and wait another 5-10 minutes for the first cooler to arrive!

That’s an awful long time to wait for blood while you watch a child hemorrhaging in front of you. So what to do? For now, use one of the existing systems to make a rapid decision. And always err on the side of activation. You can always send the blood back if you don’t need it!

Reference:  The ABC-D score improves the sensitivity in predicting need for massive transfusion in pediatric trauma patients. J Pediatr Surg. 2020 Feb;55(2):331-334. doi: 10.1016/j.jpedsurg.2019.10.008. Epub 2019 Nov 1. PMID: 31718872.

Use Of A Solid Organ Injury Protocol For Pediatrics

Kids are frequent flyers when it comes to abdominal injury, with about 15% of their injuries involving this anatomic area. Solid organ injuries, mainly the liver and spleen, are the most prevalent ones. The American Pediatric Surgical Association (APSA) published a practice guideline way back in 2000 that outlined a consistent way to care for children with solid organ injuries.

Unfortunately, they were very conservative, recommending days of bedrest, extended NPO status, very frequent blood draws, and a lengthy hospital stay. Many hospitals, including mine, developed less conservative management routines, noting that children nearly always tolerate liver and spleen injury better than adults.

The trauma group at Vanderbilt modified the APSA guidelines and, more recently, made additional changes based on a new algorithm released by the organization. This new guideline moved away from organ injury grade-based factors and embraced hemodynamic status as the overall guide to care. The Vanderbilt group performed a retrospective study comparing hospital and ICU length of stay, patient costs, readmission, and death rates using the two guidelines.

Under the old protocol, grade I-III injuries were admitted to a floor bed and higher grades to an ICU at the discretion of the surgeon. The minimum hospital stay was, at minimum, the organ injury grade. Children were kept NPO overnight and placed on bed rest for nearly one day per injury grade.

With the new protocol, children were admitted to the floor if their vital signs normalized after volume resuscitation.  Hematocrit was obtained on admission and possibly again after 6 hours, then only repeated if < 21 or a change in vitals was noted. There were no diet or activity restrictions. Children with abnormal vital signs after volume were admitted to the ICU and kept on bed rest until they normalized. Labs were drawn regularly. Length of stay was based on meeting pain control, diet, and activity goals.

Here are the factoids:

  • There were 176 children (age < 18) enrolled in the old protocol during a four-year period and 170 in the new protocol over 3.5 years
  • Both groups were similar demographically and in injury grade and ISS
  • ICU length of stay was “significantly” shorter under the new protocol (.54 vs .78 days)
  • Hospital length of stay was also “significantly” shorter (2.9 vs 3.5 days)
  • Inflation-adjusted costs were slightly higher under the new protocol ($68,042 vs $65,437) even though the authors claim the opposite in the abstract once injury grade and ISS are factored in
  • Survival was the same at 99.4%
  • Readmission rates were significantly higher under the new protocol (7.1% vs 2.3%)

The authors’ conclusions parroted these results and recommended larger studies to detail any cost advantage and identify the cause for the difference in readmission rates.

Bottom line: This study leaves a lot to be desired. The authors’ definition of “pediatric” is age < 18. As we all know, there is a big difference in “kids” who are pre- vs post-puberty. The good news is that the mean and median ages are about 11 in the study, so there should be fewer older “kids” to cause interference.

The authors reported hazard ratios for the lengths of stay, which were statistically significantly different. However, their clinical significance is in doubt. A difference of 6 ICU hours? Or two-thirds of a hospital day? I’m not impressed. 

Cost differences are basically a wash, and a deep read of the paper shows that many kids did not have an isolated solid organ injury. Non-abdominal injuries could have an Abbreviated Injury Scale score of up to 3. It is easy to imagine that these could impact both length of stay and cost.  

Finally, the readmission rates include many problems related to non-abdominal injuries, including the thorax, soft tissues, and even an epidural hematoma. After excluding these non-abdominal complications, the numbers for both protocols are so low it’s hard to believe that a good significance test can be performed.

The authors’ conclusions are correct: more work needs to be done. This paper doesn’t really teach us much since all the conclusions are extremely weak. A much better, prospective, multicenter trial should be performed. Unfortunately, getting buy-in from multiple centers/surgeons to use the same protocol in children is hard.

But with all that being said, there is no reason you can’t adopt something similar to the new protocol at your center. My own experience has shown that a more aggressive guideline gets kids home sooner and healthier and that there is no difference in readmission rates. I just need a bunch of other surgeons to duplicate these results and write them up!

Reference: A Protocol Driven Approach to Reduce Lengths of Stay for Pediatric Blunt Liver and Spleen Injury Patients. Journal of Trauma and Acute Care Surgery ():10.1097/TA.0000000000004259, January 26, 2024. | DOI: 10.1097/TA.0000000000004259 

Predicting VTE Risk In Children

There’s a lot of debate about if and at what age injured children develop significant risk for venous thromboembolism (VTE). In the adult world, it’s a little more clear cut, and nearly every patient gets some type of prophylactic device or drug. Kids, we’re not so certain about at all.

The Children’s Hospital of Wisconsin tried to tease out these factors to develop and implement a practice guideline for pediatric VTE prophylaxis. They prospectively reviewed over 4000 pediatric patients admitted over a 6 year period.

It looks like the guideline was developed using some or all of this data, then tested using regression models to determine which factors were significant. The guideline was then tweaked and a final model was implemented.

Here are the factoids:

  • 588 of the patients (14%) were admitted to the ICU, and 199 of these were identified as high-risk by the guidelines
  • Median age was 10 (this is always important in these studies)
  • VTE occurred in 4% of the ICU patients, and 10% of the high-risk ones
  • Significant risk factors included presence of central venous catheter, use of inotropes, immobilization, and GCS < 9

Bottom line: This abstract confuses me. How were the guidelines developed? What were they, exactly? And the results seem to pertain to the ICU patients only. What about the non-ICU kids? The abstract just can’t convey enough information to do the study justice. Hopefully, the oral presentation will explain all.

I prefer a very nice analysis done at the Oregon Health Science University in Portland. I wrote about this study earlier this year. The authors developed a very useful calculator that includes most of the risk factors in this model, and a few more. Input the specific risks, and out comes a nice score. The only issue is, what is the score threshold to begin prophylaxis and monitoring? Much more practical (and understandable) than this abstract. Check it out at the link below.

References:

  1. Evaluation of guidelines for injured children at high risk for venous thromboembolism: A prospective observational study. J Trauma Acute Care Surg. 2017 May;82(5):836-844.
  2. A Clinical Tool for the Prediction of Venous Thromboembolism in Pediatric Trauma Patients. JAMA Surg 151(1):50-57, 2016.

How Common Is BCVI?

Blunt carotid and vertebral artery injuries (BCVI) are an under-appreciated problem after blunt trauma. Several screening tools have been published over the years, but they tend to be unevenly applied at individual trauma centers. I will discuss them in detail in the next section.

For the longest time, the overall incidence of BCVI was thought to be low, on the order of 1-2%. This is the number I learned years ago, and it has not really changed over time.

But how do we know for sure? Well, the group at Birmingham retrospectively reviewed every CT angiogram (CTA) of the neck they did in a recent two-year period. They did this after adopting a policy of imaging each and every one of their major blunt trauma patients for BCVI. Each patient chart was also evaluated to see if the patient met any of the criteria for the three commonly used screening systems.

During the study period, a total of 6,287 of 6,800 blunt trauma patients underwent BCVI screening with CTA of the neck. They discovered that 480 patients (7.6%) were positive for BCVI!

This is a shocking 8x higher than we expected! So why hasn’t this been obvious until now? Most likely because we were previously only aware of patients who became symptomatic. Luckily, many of these patients dodge the proverbial bullet and never exhibit any symptoms at all.

And what about pediatric patients? The neurosurgery groups at the University of New Mexico and Texas Children’s Hospital analyzed data in the Kids’ Inpatient Database (KID), which contains nationally representative pediatric data from the US. Five samples were obtained three years apart, beginning in 2000 and extending to 2012.

There were nearly 650,000 admissions for blunt trauma in the database, and 2150 were associated with BCVI. There was an interesting trend: incidence in 2000 started at 0.24% and increased to 0.49% in 2012. This represents a relative doubling of cases! Keep in mind that the absolute numbers remained very small, especially compared to the adult incidence.

Children aged 4 to 13 had the lowest risk of sustaining BCVI. This was higher in younger kids (ages 0-3), probably due to their big heads. It was also higher in adolescents and young adults (age 15-20). The injury was found more often in conjunction with cervical spine, skull base, clavicle, and facial fractures, as well as in children with TBI and intracranial hemorrhage.

Over one-third of children sustaining BCVI suffered a stroke (37%). Mortality was high, with a total mortality of 13%. This increased to a 20% rate if a stroke occurred.

So why should we be worried? This is one of those clinical entities like blunt thoracic aortic disruption that potentially has terrible consequences if ignored. And it seems to be worse among children even though it is far less common. Although the number of patients who develop sequelae from their BCVI is small, suffering a stroke can be catastrophic.

Should we perform a screening study for all blunt trauma patients? It seems like overkill, or is it? Is there any way we can be more selective about it?

In the next post, I’ll review the current screening tools used to determine which patients should receive CTA and how good they are.

References:

  1. Universal screening for blunt cerebrovascular injury. J Trauma 90(2):224-231, 2021.
  2. Blunt cerebrovascular injury in pediatric trauma: a national database study. J Neurosurg Pediatr. 2019

Do We Really Need To Admit Children With Low-Grade Solid Organ Injury?

Over the years, we have slowly gotten wiser about solid organ injuries (SOI). Way back when, before CT and ultrasound, if there was a suspicion a patient had such an injury you were off to the operating room. We learned (from children, I might add) that these injuries, especially the minor ones, were not such a big deal.

However, we routinely admit adults and children with solid organ injury of any grade. Many centers have streamlined their practice guidelines so that these patients don’t spend very long in the hospital, but most are still admitted. A number of researchers from Level I pediatric centers in the US got together to see if this is really necessary.

They combed through 10 years worth of TQIP data for outcomes and timing of intervention in children with low-grade (grades 1 and 2) solid organ injury age 16 or less. Children with “trivial” extra-abdominal injuries were included to make the conclusions more generalizable.  Penetrating injuries and burns were excluded, as were those with “risk of hemorrhage” or need for abdominal exploration for reasons other than the SOI. The risk of hemorrhage was defined as a pre-existing condition or other injury that made it more likely that a transfusion might be necessary for other causes.

Here are the factoids:

  • A total of 1,019 children with low-grade SOI (liver, kidney, or spleen) were enrolled in the study, and 97% were admitted
  • There was an even distribution across age groups. Many studies over-represent teenagers; this was not the case here.
  • Median LOS was 2 days, and a quarter were admitted to the ICU
  • Only 1.7% required an intervention, usually on the first hospital day (transfusion, angiography, or laparotomy)
  • Pediatric trauma centers did not perform any of the 9 angiographic procedures, and they only performed 1 laparotomy of the 4 reported

The authors concluded that practice guidelines should be developed for adult centers caring for children to decrease the number of possibly unnecessary interventions, and that it may be feasible to manage many children with low-grade SOI outside of the hospital.

Bottom line: This is an intriguing study. The admission length and silly restrictions like bed rest, NPO, and multiple lab draws are finally approaching their end. Although this paper does have the usual limitations of using a large retrospective database, it was nicely done and thoughtfully analyzed. 

It confirms that adverse events in this population are very uncommon, and that adult centers are still too aggressive in treating children like adults. The recommendation regarding practice guidelines is very poignant and this should be a high priority.

Individual centers should determine if they have the infrastructure to identify low-risk children who have reliable families and live in proximity to a hospital with a general surgeon, or better yet, near a trauma center. Hopefully this study will help accelerate the adoption of such guidelines and practices, moving treatment for many children to the outpatient setting.

Reference: Hospital-based intervention is rarely needed for children with low-grade blunt abdominal solid organ injury: An analysis of the Trauma Quality Improvement Program registry. JTrauma 91(4):590-598, 2021.