Category: Trauma

Trauma is Still Trauma the Next Day

Acute closed head trauma is easy enough – and challenging enough.  There are validated decision instruments and guidelines, yet still plenty of CTs performed absent sound indications.  However, the question this study addresses is slightly different: what to do with those who present in a delayed fashion following minor head trauma?

The authors probably sum it up best in a reasonably concise fashion:

“Patients presenting after 24h of injury are a potentially distinct subpopulation. They could be at lower risk, as there is evidence that patients with mild/minor head injury who have injuries requiring neurosurgery will deteriorate within 24h. Alternatively, they could be a self-selecting higher-risk group attending due to the worsening or persistence of symptoms.”

These authors reviewed 2,240 patient encounters resulting in a CT scan of the head, with a goal of winnowing it down to just those performed for a traumatic indication.  Of those, 549 were performed within 24 hours of injury and 101 were delayed presentations.  There were 46 (8.4%) CTs positive for traumatic injury in the acute presentations and 10 (9.9%) in delayed, while 5 and 3 patients each underwent neurosurgical intervention, respectively.  So, the answer to their research question, at least in pragmatic terms, may be that the two forces balance each other out.

These authors also present “sensitivity” statistics regarding the utility of guidelines at predicting the presence of an important TBI, and quote a sensitivity of 70% based on chart review.  The denominator for sensitivity would more appropriately the entire population of presentations for trauma, not simply those who underwent CT scanning.  It is also probably more likely, given these patients had important TBI on CT, there may have been undocumented, guideline-compliant, indications not abstracted by chart review.

While our decision instruments for closed head injury were derived in typically an acute population, I would not yet draw any conclusions refuting their generalizability to delayed presentations.

“CT head imaging in patients with head injury who present after 24 h of injury: a retrospective cohort study”
https://www.ncbi.nlm.nih.gov/pubmed/27076439

Hello, Have You Heard of NEXUS/CCR?

In the same vein as my previous post inappropriate imaging despite the presence of PERC, this next article takes our evaluation of minor trauma to task.

This brief retrospective series looked only at presentations to the Emergency Department following “ground level fall” leading to a CT of the cervical spine.  These authors defined a “ground level fall” as fall of fewer than 3 feet or 5 stairs.  These authors then reviewed the documentation associated with each case for criteria specifically excluding the case from NEXUS or CCR and appropriate for CT imaging.

Of the 760 patients with ground-level falls included in this study, there were 7 cervical spine fractures – 6 stable, and 1 unstable.  All patients with a cervical spine fracture had documented criteria supporting appropriate CT imaging.  However, based on their retrospective review, 22.0% and 20.7% of encounters specifically documented criteria meeting NEXUS and CCR, and should not have led to CT imaging.  An additional 9.3% and 29.9% of patients had insufficient documentation of NEXUS or CCR criteria needed to determine appropriateness.

These authors posit there may be substantial cost savings to the healthcare system if these decision instruments are appropriately applied.  I tend to agree – although, there are obvious limitations to this sort of retrospective review.  It does, at least, back up my own anecdotal experience witnessing clinically questionable use of advanced imaging in minor trauma.

“Utility of computed tomography imaging of the cervical spine in trauma evaluation of ground level fall”
https://www.ncbi.nlm.nih.gov/pubmed/27032009

Survival of the Intoxicated

We are mostly all familiar with the beneficial social outcomes associated with occasional alcohol use.  However, we also see the detrimental effects of chronic use in the context of comorbid disease states.

But, it’s apparently not all bad news in a medical sense.

This retrospective evaluation of patients admitted to medical and surgical critical care units in teaching hospitals in Boston simply tracked outcomes segregated by admission blood alcohol level.  Evaluating 11,850 admissions, most admitted patients had undetectable BAC, while 638, 703, and 1,226 patients fell into their three strata of increasing BAC.

Unsurprisingly, as most patients with the highest BAC had the fewest comorbid factors and were overwhelmingly admitted due to trauma, they had the lowest mortality in the unadjusted analysis.  However, across several different types of multivariate adjustment and propensity scoring, the same survival advantage held, although substantially weakened.

There is some school of thought alcohol confers a neuroprotective and anti-inflammatory effect in the setting of acute illness.  These retrospective data, fraught with potential confounders, are inadequate to conclusively confirm or refute such a hypothesis – but it is reasonable to suggest further study of underlying mechanisms may be warranted.

“Association between blood alcohol concentration and mortality in critical illness”
http://www.ncbi.nlm.nih.gov/pubmed/26483354

Don’t Hospitalize Warfarin & Minor TBI

There have been a few retrospective, observational studies evaluating the outcomes of anticoagulated patients with minor head injury.  The incidence reported by such series ranges from 6% in observation with mandatory repeat CT, to 0.6% with discretionary CT.

This series from Singapore reports: 0.3%.
In this series, all patients taking warfarin and having minor head trauma underwent protocolized initial CT and hospitalization for observation.  Repeat CT was performed, however, only at the discretion of the treating physicians.  Of the 295 patients hospitalized, only 11 underwent repeat CT, and only 1 abnormality was identified.  That one patient underwent neurosurgical intervention.  Of the remainder, no patients returned within two weeks of the initial incident with a further episode of delayed bleeding.  Thus, 0.3%.
Is it the difference between mandatory and discretionary repeat CT resulting in the wide range of reported incidence of delayed hemorrhage?  But, if there aren’t any symptomatic changes, are the extra hemorrhages detected clinically important?
Interestingly enough, they also reported three deaths from nosocomial pneumonia.  So, yes, the risk of delayed hemorrhage is non-zero – but likely lower than the risks associated with hospitalization.
“Outcomes of warfarinized patients with minor head injury and normal initial computer tomographic scan”

NEXUS Chest (Again)

This isn’t the first go ‘round for these authors.  In 2013, they published their first attempt – which demonstrated a sensitivity of 98.8% for thoracic injury, but a specificity of 13.3%.  The rule was, essentially, minimal improvement over clinical judgement and reliably decrease resource utilization.

In another massive effort, these authors enrolled 11,477 patients in 8 trauma centers – 6,002 in the derivation phase and 5,475 in the validation phase.  Based on their prior work, they evaluated each for the presence of 14 potentially predictive features.  Following data collection for the derivation phase, recursive partitioning was used to develop two decision instruments: one for “major” injuries requiring intervention, and one for “major and minor” injuries requiring a minimum of observation.

Their new criteria, comprised of about half of the 14 tested, were much improved over the prior study.  In the validation phase, the “major and minor” decision instrument had sensitivity of 99.2% for major injuries and 95.4% for major or minor injury.  Specificity was still poor at 25.5%, but improved from the prior study.

This validation phase, however, included only those undergoing CXR and CT chest – only 2,628 of the 5,475 enrolled.  The authors state “we have previously demonstrated that the clinically significant injury rate in this non-imaged group of patients approaches zero and is therefore negligible” – which certainly applies to the “major” injuries, but far less reliably to “major or minor”.  However, the more important implication is for the context of use for this decision instrument.  This instrument should not be applied to all trauma presentations – but, rather, to all trauma presentations for which CT chest imaging is initially judged necessary.  Only then, in the subset of patients who were otherwise on-their-way to CT, would this decision instrument potentially reduce imaging.  The authors do not provide its test characteristics in an all-comers population, nor provide comparative details regarding the characteristics of those imaged versus those not, so any further speculation is simply that.

As with the previously proposed NEXUS Chest, the same limitation applies – this is a one-way decision-instrument intended only to obviate CT, not inform clinicians for whom CT is needed.  As such, it is subject to the cognitive biases resulting from one-way decision-instruments, paradoxically leading to increased resource utilization.  It is, perhaps, the PERC rule for trauma – and do you think incorporating PERC increases, or decreases, CTPA?

“Derivation and Validation of Two Decision Instruments for Selective Chest CT in Blunt Trauma: A Multicenter Prospective Observational Study (NEXUS Chest CT)”
http://journals.plos.org/plosmedicine/article?id=10.1371/journal.pmed.1001883

A Call to Retire Routine C-Spine Immobilization

Remember the heartwarming children’s tale of the young woman with the ribbon around her neck?  Once removed, the head falls from the body, and the unfortunate woman expires.  Thus, the inspiration and evidential basis for modern trauma care utilizing immobilization of the cervical spine.

This article asks a very simple question: is there evidence to support the notion of incidental cerebrospinal movement resulting in subsequent paralysis?  Their answer: probably not.

These authors review several thousand abstracts to extract twelve publications describing a mere 41 cases of patients who were not completely immobilized, and thence suffered subsequent neurologic deterioration.  The individual cases reported upon provide, generally, rather spotty detail regarding the circumstances.  Some patients had additional falls or trauma in the ED, others were intoxicated and combative, while many others seemed to have gradual worsening without a specific event.

These authors propose this gradual worsening represents the primary time scale of neurologic deterioration – and suggest the suspected precipitating events documented by these cases represent contextual red herrings.  Rather than becoming tetraplegic as a consequence of repositioning in the Emergency Department, it is more likely clinical manifestations result from ligamentous disruption, bleeding, and edema related to the primary injury, and immobilization would not have prevented their progression.

Of course, this paucity of documented examples cannot represent an exhaustive report of all known secondary deterioration after an initial, non-immobilized injury.  However, just as erroneous is the presumption that immobilization prevents such secondary deterioration – particularly when coupled with the known inconveniences and harms of mass immobilization during transport and evaluation.

It’s time for routine cervical spine immobilization to go!  However, such discontinuation need be undertaken in such a setting as capable of detecting any adverse events resulting from such.

“Early Secondary Neurologic Deterioration After Blunt Spinal Trauma: A Review of the Literature”
http://www.ncbi.nlm.nih.gov/pubmed/26394232

Soothing Songs and the CT Scanner

Yes, this is a trial of music therapy.  In the Emergency Department.  What fun!

This is a convenience sample of 62 children up to three years of age being referred for head CT after minor trauma, randomized to either soothing music or none.  Children were assessed for calmness by a visual analog scale of anxiety and a Modified Ramsay Sedation Scale before transport to CT.  Then, music was either present or absent while the child was being positioned on the scanner.  A second assessment of anxiety was then performed prior to CT.

The good news, as reported by the authors:

In conclusion, measured on a VAS, there was a significant decrease in agitation in children undergoing a head CT when children’s songs with integrated heart beat sounds were played before and during the procedure.

Unfortunately for their comparison, the control group was quite calm to start – with little room to improve – while the experimental group was fussier at baseline.  And, even though the CT introduced some agitation into the control group, nearly identical numbers of patients in each group successfully completed their imaging.  So, even though I think their intervention has value, the reliability of their conclusion is probably threatened by the chance baseline differences between groups.

But, it otherwise makes sense – and, it’s harmless, zero-cost intervention – so, why not?

“Randomized single-blinded clinical trial on effects of nursery songs for infants and young children’s anxiety before and during head computed tomography”
http://www.ncbi.nlm.nih.gov/pubmed/26314215

Clinicians or Statistics for Pediatric Abdominal Injury

PECARN is a wonderful thing.  Any individual pediatric facility sees a handful of children.  A handful, however, multiplied by 20, becomes potentially practice-changing.

And, this is an article further exploring the PECARN pediatric abdominal trauma prediction instrument, comparing its utility to typical clinician judgment.  As part of the initial derivation study, the surveyors asked each clinician to rate the likelihood of intra-abdominal injury, stratified <1%, 1-5%, 6-10%, 11-50%, or >50%.  Turns out, clinician judgement wasn’t too bad.

  • Of 9,252 children with <1% chance of injury requiring intervention, 35 (0.4%) had injuries identified.
  • Of 1,793 between 1-5% chance, 40 (2.2%).
  • Of 506 between 6-10% chance, 33 (6.5%).
  • Of 281 between 11-50% chance, 59 (21.0%).
  • Of 81 greater 50% chance, 36 (41.4%).

The problem with these data?  5,318 CTs were performed to identify 203 significant injuries, including 3,016 in those with <1% chance.

The prediction rule was both better and worse.  It was more sensitive than clinician judgment, but also less specific.  For an endeavor attempting to decrease CT utilization in children, it’s still not quite clear where this fits in – and whether using it in a fashion similar to PERC or D-dimer wouldn’t necessarily increase imaging.  It may, as these authors discuss, have more value in Emergency Departments without the same level of comfort managing traumatically injured children, as it may yet in face reduce imaging in that context.

“Comparison of Clinician Suspicion Versus a Clinical Prediction Rule in Identifying Children at Risk for Intra-abdominal Injuries After Blunt Torso Trauma”

The No-CT in Trauma Experience

In many trauma centers, the Emergency Department role is essentially: place an IV for which contrast may be delivered for CT.  Oh, yes, there’s some airway management, perhaps a FAST exam, some rolling and cutting of clothing, and the remainder of our expertise should not be diminished, but modern management has been distilled to: trauma = pan-scan.

Except in San Diego.

This fascinating paper describes 11 years of experience at a Level 1 trauma center in which the vast minority of their patients underwent automatic CT.  Between the hours of 8AM and 11PM, a resident and staff ultrasonographer were available for ultrasound examination of trauma patients.  At the discretion of the attending surgeon, the ultrasonographers performed an examination consisting of seven abdominal windows, bilateral visceral organ windows, and cardiac windows.

And, of the 19,126 trauma patients included in this study, essentially all patients presenting between 8AM and 11PM underwent this ultrasound.  Minus the 13 patients who went directly to the OR, this constitutes 12,565 patients initially screened with ultrasound.  Of these, 12,070 were judged to be negative examinations.  By the authors definition of false negative, a positive exploratory laparotomy finding, only 35 ultimately required such – a false negative rate of 0.29%.  Comparatively, CT was performed off-hours in 6,548 patients, and had a 0.1% false negative rate.

There were, of course, a mix of patients with positive ultrasound results who ultimately had negative CTs, and 1,119 negative ultrasounds who underwent CT with a 86 positive results.  So, there’s a lot of details and hidden corners to evaluate and analyze beyond their narrow definition.  But, still, impressively, their trauma protocol at a Level 1 center managed to spare half the patients the ubiquitous pan-scan.

Fascinating!

“Complete ultrasonography of trauma in screening blunt abdominal trauma patients is equivalent to computed tomographic scanning while reducing radiation exposure and cost”
http://www.ncbi.nlm.nih.gov/pubmed/26218686

A Little Intubation Checklist Magic

In the interests of patient safety, many have turned to peri-procedural checklists.  Rather than,
essentially, “winging it”, a standardized protocol is followed each time, reducing the chance of an important omission.

These authors describe a checklist intervention for, as they describe, the high-risk procedure of endotracheal intubation in the setting of trauma.  The checklist involves, generally, assignment of roles, explicit back-up airway planning, and adequate patient positioning.  The authors used a before-and-after design using video review of all intubation events to compare steps performed.

In the six-month pre-checklist period, 7 of 76 intubation events resulted in complications – 6 desaturations, 2 emesis, and 2 hypotension.  In the post-intervention period, using the checklist, events were reduced to a single episode of desaturation in 65 events.  So, success?

As with every before-and-after study, it is hard to separate the use of the checklist to the educational diffusion associated with checklist exposure.  Would another, less intrusive, intervention been just successful?  Will the checklist lose effectiveness over time as it is superseded by newer safety initiatives?  And, most importantly, what did operators actually do differently after checklist implementation?

Only 4 of 15 checklist elements differed from the pre-checklist period: verbalization of backup intubation technique (61.8% vs. 90.8%), pre-oxygenation (47.3% vs. 75.4%), team member roles verbalized (76.4% vs. 98.5%), and optimal patient positioning (80.3% vs. 100%).  If only four behaviors were substantially changed, are they responsible for the outcomes difference – which, technically, is solely episodes of hypoxia?

Their intervention seems reasonable, and the procedure is likely high-risk enough to warrant a checklist.  However, I probably would not implement their specific checklist, as some refinement to the highest-yield items would probably be of benefit.

“A Preprocedural Checklist Improves the Safety of Emergency Department Intubation of Trauma Patients”
http://www.ncbi.nlm.nih.gov/pubmed/26194607