SonoStudy: >12,000 kids – Identifying factors putting kids at low risk, not needing CT after trauma

There has been quite a bit of press lately on this –  Here and Here - And for good reason. With the ALARA principle, and being a pediatric population which has been studied so many times with regard to trauma and the need for CT, a recent study by Holmes et al published in Annals of Emergency Medicine did a multi-site study enrolling >12,000 kids and identified 7 factors that places children at very low risk for injury not requiring abdominal CT. A prior post discusses a study done by the same author and my thoughts of pediatric US in trauma. BTW – Dr. Holmes also discusses low risk factors for adult patients in a prior study too.

The prediction rule for pediatric patients consisted of (in descending order of importance):

No evidence of abdominal wall trauma or seat belt sign,

Glasgow Coma Scale score greater than 13,

No abdominal tenderness,

No evidence of thoracic wall trauma,

No complaints of abdominal pain,

No decreased breath sounds, and

No vomiting.

Now, I dont know about you, but to me it is quite obvious – we just now have a nicely powered study that we can use for all the doctors who want to CT despite all of the above being negative. The authors say that if any one of the above exist then a decision by the physician should be made as to what the next best management step would be – observation period with serial exams, ultrasound (holla!), CT – are all options depending on clinical judgement. Below is the abstract:

Study objective: We derive a prediction rule to identify children at very low risk for intra-abdominal injuries undergoing acute intervention and for whom computed tomography (CT) could be obviated.

Methods: We prospectively enrolled children with blunt torso trauma in 20 emergency departments. We used binary recursive partitioning to create a prediction rule to identify children at very low risk of intra-abdominal injuries undergoing acute intervention (therapeutic laparotomy, angiographic embolization, blood transfusion for abdominal hemorrhage, or intravenous fluid for ≥2 nights for pancreatic/gastrointestinal injuries). We considered only historical and physical examination variables with acceptable interrater reliability.

Results: We enrolled 12,044 children with a median age of 11.1 years (interquartile range 5.8, 15.1 years). Of the 761 (6.3%) children with intra-abdominal injuries, 203 (26.7%) received acute interventions. The prediction rule consisted of (in descending order of importance) no evidence of abdominal wall trauma or seat belt sign, Glasgow Coma Scale score greater than 13, no abdominal tenderness, no evidence of thoracic wall trauma, no complaints of abdominal pain, no decreased breath sounds, and no vomiting. The rule had a negative predictive value of 5,028 of 5,034 (99.9%; 95% confidence interval [CI] 99.7% to 100%), sensitivity of 197 of 203 (97%; 95% CI 94% to 99%), specificity of 5,028 of 11,841 (42.5%; 95% CI 41.6% to 43.4%), and negative likelihood ratio of 0.07 (95% CI 0.03 to 0.15).

Conclusion: A prediction rule consisting of 7 patient history and physical examination findings, and without laboratory or ultrasonographic information, identifies children with blunt torso trauma who are at very low risk for intra-abdominal injury undergoing acute intervention. These findings require external validation before implementation.

SonoStudy: Flat IVC predictor of poor prognosis in trauma – A-B-C-D-Echo in Trauma!

A recent study on the IVC and trauma and acute surgical patients was done by Ferrada et al, and despite the giggles I get when I read it and how they describe the IVC as “Fat ” or “Flat”, it is an important topic to discuss as it is one of the few articles out there that correlate the iVC to trauma patients and acute surgical patients. First off, it is a retrospective study, which can make it difficult to assess patients with similar factors without other factors coming into play (but when is that NOT the case, honestly?) They did compare the IVC in all patients and studied those patients who seemed sick as well – ICU admission, immediate surgery need, transfusion needed. The power of the study was good but not great – 101 patients studied – varying in type of trauma and surgical need. There was a previous study published in the Journal of Trauma in 2011 that stated CT evidence of flat IVC was an indicator for hypovolemia and  poor prognostic indicator for blunt solid organ injuries – this confirmed a study done in 2010 stating the same thing. Thankfully, ultrasound can get you that information much more immediately than CT!

This month, another study by the same author (Ferrada) in the Journal of trauma and acute care surgery entitled A-B-C-D-Echo (I know, love it!) stated that adding limited transthoracic echo, including the IVC, will benefit trauma patients with results showing “Flat inferior vena cava was associated with an increased incidence of ICU admission (p < 0.0076) and therapeutic operation (p < 0.0001). Of the 148 patients, 27 (18%) had LTTE results indicating euvolemia. The diagnosis in these cases was head injury (n = 14), heart dysfunction (n = 5), spinal shock (n = 4), pulmonary embolism (n = 3), and stroke (n = 1). Of the patients, 121 had LTTE results indicating hypovolemia. Twenty-eight hypovolemic patients had a negative or inconclusive Focused Assessment with Sonography for Trauma examination finding (n = 18 penetrating, n = 10 blunt), with 60% having blood in the abdomen confirmed by surgical exploration or computed tomographic scan. Therapy was modified as a result of LTTE in 41% of cases. Strikingly, in patients older than 65 years, LTTE changed therapy in 96% of cases.”

Below are the Abstracts of the studies highlighted by Ferrada:

“Flat inferior vena cava (IVC) on ultrasound examination has been shown to correlate with hypovolemic status. We hypothesize that a flat IVC on limited echocardiogram (LTTE) performed in the emergency room (ER) correlates with poor prognosis in acutely ill surgical patients. We conducted a retrospective review of all patients undergoing LTTE in the ER from September 2010 until June 2011. IVC diameter was estimated by subxiphoid window. Flat IVC was defined as diameter less than 2 cm. Fat IVC was defined as diameter greater than 2 cm. Need for intensive care unit admission, blood transfusion requirement, mortality, and need for emergent operation between patients with flat versus Fat IVC were compared. One hundred one hypotensive patients had LTTE performed in the ER. Average age was 38 years. Admission diagnosis was blunt trauma (n = 80), penetrating trauma (n = 13), acute care surgery pathology (n = 7), and burn (n = 1). Seventy-four patients had flat IVC on initial LTTE. Compared with those with fat IVC, flat patients were found have higher rates of intensive care unit admission (51.3 vs 14.8%; P = 0.001), blood transfusion requirement (12.2 vs 3.7%), and mortality (13.5 vs 3.7%). This population also underwent emergent surgery on hospital Day 1 more often (16.2 vs 0%; P = 0.033). Initial flat IVC on LTTE is an indicator of hypovolemia and a predictor of poor outcome.”

ABCDEcho:

“BACKGROUND: Limited transthoracic echocardiogram (LTTE) has been introduced as a technique to direct resuscitation in intensive care unit (ICU) patients. Our hypothesis is that LTTE can provide meaningful information to guide therapy for hypotension in the trauma bay.

METHODS: LTTE was performed on hypotensive patients in the trauma bay. Views obtained included parasternal long and short, apical, and subxyphoid. Results were reported regarding contractility (good vs. poor), fluid status (flat inferior vena cava [hypovolemia] vs. fat inferior vena cava [euvolemia]), and pericardial effusion (present vs. absent). Need for surgery, ICU admission, Focused Assessment with Sonography for Trauma examination results, and change in therapy as a consequence of LTTE findings were examined. Data were collected prospectively to evaluate the utility of this test.

RESULTS: A total of 148 LTTEs were performed in consecutive patients from January to December 2011. Mean age was 46 years. Admission diagnosis was 80% blunt trauma, 16% penetrating trauma, and 4% burn. Subxyphoid window was obtained in all patients. Parasternal and apical windows were obtained in 96.5% and 11%, respectively. Flat inferior vena cava was associated with an increased incidence of ICU admission (p < 0.0076) and therapeutic operation (p < 0.0001). Of the 148 patients, 27 (18%) had LTTE results indicating euvolemia. The diagnosis in these cases was head injury (n = 14), heart dysfunction (n = 5), spinal shock (n = 4), pulmonary embolism (n = 3), and stroke (n = 1). Of the patients, 121 had LTTE results indicating hypovolemia. Twenty-eight hypovolemic patients had a negative or inconclusive Focused Assessment with Sonography for Trauma examination finding (n = 18 penetrating, n = 10 blunt), with 60% having blood in the abdomen confirmed by surgical exploration or computed tomographic scan. Therapy was modified as a result of LTTE in 41% of cases. Strikingly, in patients older than 65 years, LTTE changed therapy in 96% of cases.

CONCLUSION: LTTE is a useful tool to guide therapy in hypotensive patients in the trauma bay.”

SonoStudy: >29,000 patients: Utility of cardiac portion of FAST scan: should we be doing it?

Should we keep doing the echo with the FAST scan? What does it truly add? Ill never forget the story I heard about a 35 yr old male blunt trauma victim after single vehicle motor vehicle accident who lost his pulse en route.  The echo part of the FAST scan showed tamponade in the first 5 minutes of evaluation and ACLS/ATLS management. He survived due to early pick up) and walked out of the hospital. Or, the penetrating epigastric stab wound victim who was tachycardic and hypotensive with no tamponade or pericardial effusion seen on FAST (helping us rule out tamponade as the cause of shock). But, when looking at the studies….a recent one from JEM states:

“Background

Focused assessment with sonography in trauma (FAST) is widely used and endorsed by guidelines, but little evidence exists regarding the utility of the cardiac portion in blunt trauma. The traditional FAST includes the routine performance of cardiac sonography, regardless of risk for hemopericardium.

Study Objectives

Our goal was to estimate the prevalence of hemopericardium due to blunt trauma and determine the sensitivity of certain variables for the presence of blunt hemopericardium.

Methods

We performed a retrospective chart review of two institutional databases at a large urban Level I trauma center to determine the prevalence of blunt hemopericardium and cardiac rupture and incidental or insignificant effusions. We evaluated the sensitivity of major mechanism of injury, hypotension, and emergent intubation for blunt hemopericardium and cardiac rupture.

Results

Eighteen patients had hemopericardium and cardiac rupture (14 and 4, respectively) out of 29,236 blunt trauma patients in the Trauma Registry over an 8.5-year period. The prevalence was 0.06% (95% confidence interval [CI] 0.04–0.09%). The prevalence of incidental or insignificant effusions was 0.13% (95% CI 0.09–0.18%). One case of blunt hemopericardium was identified in the emergency ultrasound database out of 777 cardiac ultrasounds over a 3-year period. No patient with blunt hemopericardium or cardiac rupture presented without a major mechanism of injury, hypotension, or emergent intubation.

Conclusion

Blunt hemopericardium is rare. High-acuity variables may help guide the selective use of echocardiography in blunt trauma.”

So, I would ask: is it worth the 20 seconds it takes to look at the heart to pick up those patients who had a positive scan? And, is it worth the 20 seconds it takes to look at the heart to rule it out? – i say – yes. But I get it – it may be negative A LOT of the time.

SonoParty…&Journal Club… in Northern CA: Stanford, UCSF, UCSF/Fresno, UC Davis, Highland, Kaisers

Prior to leaving for ACEP in Denver, CO there was a gathering (aka “party”) at my home in sunny San Francisco with my friends and colleagues in emergency medicine / emergency ultrasound  - from all of the ultrasound programs in the region – it was amazing… and yes, wine was served! … along with pizza (of course!) We discussed 4 articles as listed below and I took down the US pearls noted from the various physicians who attended:

SonoStudy: False negative FAST scans: association with patient characteristics/injuries/outcomes?

A study recently published in Annals of Emergency Medicine by Laselle et al attempt to estimate associations between false negative FAST results and patient characteristics, specific organ injuries, and patient outcomes by doing a retrospective analysis of consecutive patients who had a blunt abdominal trauma with pathologic free fluid found by CT, DPL (yeah, I know, weird), laparotomy, or autopsy (ouch!). Over 300 enrolled and 162 had a false negative FAST scan.

SonoStudy: >6,500 kids studied – FAST scan in kids with blunt trauma – does it help?

In the July issue of ACEP news: there was an article which highlighted a multi-center study’s results of over 6,000 kids that discusses the FAST scan in the pediatric population.(study has yet to be published, as I cannot find it anywhere)  (FAST = focused assessment with sonography for trauma). It was discussed at SAEM as well. The findings are not surprising: FAST scan is done with low frequency in kids and when it is, it has a low sensitivity and high specificity (if negative, it does not rule out injury). But, one of the exciting parts of it was that low and moderate-risk kids got fewer CT scans when a FAST scan was performed. One of the main authors is Dr. James Holmes, from UC Davis, who has studied ultrasound in trauma extensively, most recently highlighted in JAMA assessing adult patients and the predictors of injury, concluding the FAST scan being the most accurate.

SonoStudy: Trauma registry investigation of 1,600+ patients: The abdomen must be explored first in blunt trauma!

In the current issue of the Archives of Surgery by Berg et al, through the JAMA network, highlighted in the ACEP news , “To our knowledge, the current study is the most complete examination of injury patterns and outcomes in the largest series of blunt thoracoabdominal trauma patients to date,” wrote study investigators Dr. Regan J. Berg and colleagues in the division of trauma surgery and surgical critical care, Los Angeles County + University of Southern California Medical Center in Los Angeles. Blunt trauma was defined as an Abbreviated Injury Score of 2 or more in both the chest and abdomen) who were admitted to the LAC+USC Medical Center between January 1996 and December 2010. They investigated trauma patterns, resulting injuries, need for operative care, and clinical outcomes – -  and found that ”In cases of blunt thoracoabdominal trauma, the abdomen should be the initial cavity of exploration in patients requiring emergent surgery without direct radiologic data, based on the results of a trauma registry and medical record review of 1,661 patients.”

SonoStudy: Survival potential – US evaluating cardiac motion during traumatic cardiac arrest… AND an assessment of the literature

An interesting study in the July issue of the Journal of Trauma and Acute Care Surgery (see full article here) discussing the utility of bedside ultrasound during traumatic cardiac arrest. For anyone who works at a trauma center, or who just so happens to receive a patient dropped off by a friend on the driveway of the ED (we have all had that happen), or who received a patient by ambulance who is in cardiac arrest at a non-trauma center to soon find evidence of trauma upon exposure of the patient….. this study is quite relevant when it comes to survival potential and how bedside ultrasound may help. What they say….

SonoApp: Lung Ultrasound – The down low of pneumo…with the help of Lichtenstein, of course

Lung ultrasound (aka thoracic US) is one of the currently most popular applications of bedside ultrasound. It was found to be more sensitive and specific than chest XRay for pleural effusion, pulmonary edema, and pneumothorax evaluation…. how about them apples?! There have been some recent studies suggesting that in the heat of the moment for trauma patients, the sensitivity may be slightly lower than other studies state, but it is still better than chest Xray! Not only does it take a long time to get that chest Xray done in your ED or in through your ambulatory care practice, but its more expensive than bedside limited ultrasound for the patient as well…. lets not even talk about the radiation (yes, I know, Chest Xray radiation is minimal, but it’s still radiation). The evaluation of the lungs takes no more than 3 minutes, and ultrasound machines can be found in your pocket now (should you want that kind of VERY COOL technology). US machines can also be the size of a laptop with better resolution and multiple probe capabilities – so, needless to say, its easy, portable, fast, and more accurate. Now let’s talk…