Complete ultrasonography of trauma in screening blunt abdominal trauma patients is equivalent to computed tomographic scanning while reducing radiation exposure and cost

Lung ultrasonography underdiagnoses clinically significant pneumothorax

BACKGROUND

Ultrasonography for trauma is an integral part of the Advanced Trauma Life Support algorithm and supported extensively in the literature. The reliability of chest ultrasonography as a screening examination for pneumothorax during initial trauma evaluation is unclear. We performed a prospective study where we hypothesized that chest ultrasonography would have low sensitivity for detecting clinically significant pneumothorax.

METHODS

A prospective observational analysis of patients with blunt chest trauma at a level 1 trauma center was performed. Patients included had supine chest radiography and chest ultrasonography performed prior to intervention as well as confirmatory computed tomographic imaging. All chest ultrasonography was performed in the trauma bay by a registered sonographer. All imaging was evaluated by an attending trauma surgeon and radiologist in real time.

RESULTS

Of 2,185 patients screened with a diagnosis of blunt thoracic trauma, 1,489 patients had chest radiography, chest ultrasonography, and confirmatory computed tomography and were included for analysis. Patients were 71% male, with median age of 42 years, and mean Injury Severity Score of 6. The sensitivity of chest ultrasonography to detect pneumothorax was low. Chest ultrasonography had a false negative rate of 72% (n = 58), with 22% (n = 13) undergoing tube thoracostomy. Patients with false negative examinations had lower initial O2 saturation and systolic blood pressure and were more likely to have rib fractures compared with true negative chest ultrasonography examinations.

CONCLUSION

Chest ultrasonography performed on initial trauma evaluation has low sensitivity with a high rate of false negative examinations. Because many of these false negative results are clinically significant requiring thoracostomy, using chest ultrasonography alone to screen for pneumothorax should be done with caution.

Post-traumatic Liver Pseudoaneurysms: Rare but Serious Sequela

INTRODUCTION

The liver is the most commonly injured organ after blunt abdominal trauma. Nonoperative management is the standard of care in stable individuals. Liver injuries, particularly high-grade injuries, can develop pseudoaneurysms (PSAs), which can rupture and cause life-threatening bleeding, even after hospital discharge. There is no consensus on whether patients should receive predischarge contrast computed tomography (CT) screening, or at what time interval after injury, nor which patients are at the highest risk for PSA. The purpose of this study was to identify the rates of PSA in our population and potential risk factors for their formation.

METHODS

The trauma registry at our Level 1 urban trauma center was queried for patients admitted with liver injuries between 2015 and 2021. Demographic information was collected from the registry. Individual charts were then reviewed for timing of CT scans, CT findings, interventions, and complications. Liver injury grade was assessed using radiology reports or operative findings. The frequency of PSAs was then analyzed using descriptive statistics using Microsoft Excel and SPSS for odds ratio.

RESULTS

A total of 172 patients were admitted with liver injuries during the study period. 130 patients received a CT scan diagnosing liver injury, 42 were diagnosed with liver injury intraoperatively. Of the 130 patients (59.9%) which received follow-up CT scans, six (6.5%) developed PSA, four of which being from penetrating injuries (odds ratio, 6.95).

CONCLUSIONS

This study demonstrated a low incidence of PSA consistent with the known literature. We found the majority of the PSA developed following penetrating injury. This may represent a significant indication for follow-up imaging regardless of grade. A larger study will be necessary to identify those most at risk for PSA formation and determine the best PSA screening algorithm.

Not so FAST-Chest ultrasound underdiagnoses traumatic pneumothorax

BACKGROUND

Ultrasonography for trauma is a widely used tool in the initial evaluation of trauma patients with complete ultrasonography of trauma (CUST) demonstrating equivalence to computed tomography (CT) for detecting clinically significant abdominal hemorrhage. Initial reports demonstrated high sensitivity of CUST for the bedside diagnosis of pneumothorax. We hypothesized that the sensitivity of CUST would be greater than initial supine chest radiograph (CXR) for detecting pneumothorax.

METHODS

A retrospective analysis of patients diagnosed with pneumothorax from 2018 through 2020 at a Level I trauma center was performed. Patients included had routine supine CXR and CUST performed prior to intervention as well as confirmatory CT imaging. All CUST were performed during the initial evaluation in the trauma bay by a registered sonographer. All imaging was evaluated by an attending radiologist. Subgroup analysis was performed after excluding occult pneumothorax. Immediate tube thoracostomy was defined as tube placement with confirmatory CXR within 8 hours of admission.

RESULTS

There were 568 patients screened with a diagnosis of pneumothorax, identifying 362 patients with a confirmed pneumothorax in addition to CXR, CUST, and confirmatory CT imaging. The population was 83% male, had a mean age of 45 years, with 85% presenting due to blunt trauma. Sensitivity of CXR for detecting pneumothorax was 43%, while the sensitivity of CUST was 35%. After removal of occult pneumothorax (n = 171), CXR was 78% sensitive, while CUST was 65% sensitive (p < 0.01). In this subgroup, CUST had a false-negative rate of 36% (n = 62). Of those patients with a false-negative CUST, 50% (n = 31) underwent tube thoracostomy, with 85% requiring immediate placement.

CONCLUSION

Complete ultrasonography of trauma performed on initial trauma evaluation had lower sensitivity than CXR for identification of pneumothorax including clinically significant pneumothorax requiring tube thoracostomy. Using CUST as the primary imaging modality in the initial evaluation of chest trauma should be considered with caution.

LEVEL OF EVIDENCE

Diagnostic Test study, Level IV.

Ultrasonographic inferior vena cava diameter response to trauma resuscitation after 1 hour predicts 24-hour fluid requirement

BACKGROUND

Identification of occult hypovolemia in trauma patients is difficult. We hypothesized that in acute trauma patients, the response of ultrasound-measured minimum inferior vena cava diameter (IVCDMIN), IVC Collapsibility Index (IVCCI), minimum internal jugular diameter (IJVDMIN) or IJV Collapsibility Index (IJVCI) after up to 1 hour of fluid resuscitation would predict 24-hour resuscitation intravenous fluid requirements (24FR).

METHODS

An NTI-funded, American Association for the Surgery of Trauma Multi-Institutional Trials Committee prospective, cohort trial was conducted at four Level I Trauma Centers. Major trauma patients were screened for an IVCD of 12 mm or less or IVCCI of 50% or less on initial focused assessment sonographic evaluations for trauma. A second IVCD was obtained 40 minutes to 60 minutes later, after standard-of-care fluid resuscitation. Patients whose second measured IVCD was less than 10 mm were deemed nonrepleted (NONREPLETED), those 10 mm or greater were repleted (REPLETED). Prehospital and initial resuscitation fluids and 24FR were recorded. Demographics, Injury Severity Score, arterial blood gasses, length of stay, interventions, and complications were recorded. Means were compared by ANOVA and categorical variables were compared via χ. Receiver operating characteristic curves analysis was used to compare the measures as 24FR predictors.

RESULTS

There were 4,798 patients screened, 196 were identified with admission IVCD of 12 mm or IVCCI of 50% or less, 144 were enrolled. There were 86 REPLETED and 58 NONREPLETED. Demographics, initial hemodynamics, or laboratory measures were not significantly different. NONREPLETED had smaller IVCD (6.0 ± 3.7 mm vs. 14.2 ± 4.3 mm, p < 0.001) and higher IVCCI (41.7% ± 30.0% vs. 13.2% ± 12.7%, p < 0.001) but no significant difference in IJVD or IJVCCI. REPLETED had greater 24FR than NONREPLETED (2503 ± 1751 mL vs. 1,243 ± 1,130 mL, p = 0.003). Receiver operating characteristic analysis indicates IVCDMIN predicted 24FR (area under the curve [AUC], 0.74; 95% confidence interval [CI], 0.64-0.84; p < 0.001) as did IVCCI (AUC, 0.75; 95% CI, 0.65-0.85; p < 0.001) but not IJVDMIN (AUC, 0.48; 95% CI, 0.24-0.60; p = 0.747) or IJVCI (AUC, 0.54; 95% CI, 0.42-0.67; p = 0.591).

CONCLUSION

Ultrasound assessed IVCDMIN and IVCCI response initial resuscitation predicts 24-hour fluid resuscitation requirements.

LEVEL OF EVIDENCE

Diagnostic tests or criteria, level II.

Extra-parenchymal splenic abnormalities not vascular injury predict need for primary splenectomy

PURPOSE

Radiographic indications for primary splenectomy (PS) in blunt splenic injury (BSI) after radiographic diagnosis are unknown. Improved understanding of radiographic characteristics of patients requiring splenectomy will help to appropriately triage patients to PS or non-operative management (NOM).

METHODS

A retrospective, single-center review was performed of BSI diagnosed with computerized tomography (CT). Patients undergoing splenectomy prior to CT diagnosis were excluded.

RESULTS

BSI was identified in 195 patients. On logistic regression, only subcapsular hematoma presence (OR 7.521, p = 0.002) and left upper quadrant hemoperitoneum (OR 6.146, p = 0.03) were associated with need for PS, while splenic laceration length, number of pseudoaneurysms (PSA), and active contrast extravasation (NS for all) were not.

CONCLUSIONS

Need for PS is predicted by extra-parenchymal pathology in subcapsular hematoma and hemoperitoneum. Splenic vascular injuries through PSA and active contrast extravasation do not predict the need for PS and can be considered for NOM.

Improved medical student perception of ultrasound using a paired anatomy teaching assistant and clinician teaching model

This study describes a new teaching model for ultrasound (US) training, and evaluates its effect on medical student attitudes toward US. First year medical students participated in hands-on US during human gross anatomy (2014 N = 183; 2015 N = 182). The sessions were facilitated by clinicians alone in 2014, and by anatomy teaching assistant (TA)-clinician pairs in 2015. Both cohorts completed course evaluations which included five US-related items on a four-point scale; cohort responses were compared using Mann-Whitney U tests with significance threshold set at 0.05. The 2015 survey also evaluated the TAs (three items, five-point scale). With the adoption of the TA-clinician teaching model, student ratings increased significantly for four out of five US-items: "US advanced my ability to learn anatomy" increased from 2.91 ± 0.77 to 3.35 ± 0.68 (P < 0.0001), "Incorporating US increased my interest in anatomy" from 3.05 ± 0.84 to 3.50 ± 0.71 (P < 0.0001), "US is relevant to my current educational needs" from 3.36 ± 0.63 to 3.54 ± 0.53 (P = 0.015), and "US training should start in Phase I" from 3.36 ± 0.71 to 3.56 ± 0.59 (P = 0.010). Moreover, more than 84% of students reported that TAs enhanced their understanding of anatomy (mean 4.18 ± 0.86), were a valuable part of US training (mean 4.23 ± 0.89), and deemed the TAs proficient in US (mean 4.24 ± 0.86). By using an anatomy TA-clinician teaching team, this study demonstrated significant improvements in student perceptions of the impact of US on anatomy education and the relevancy of US training to the early stages of medical education. Anat Sci Educ 11: 175-184. © 2017 American Association of Anatomists.

Ruling out intra-abdominal injuries in blunt trauma patients using clinical criteria and abdominal ultrasound

OBJECTIVE

to identify victims of blunt abdominal trauma in which intra-abdominal injuries can be excluded by clinical criteria and by complete abdominal ultrasonography.

METHODS

retrospective analysis of victims of blunt trauma in which the following clinical variables were analyzed: hemodynamic stability, normal neurologic exam at admission, normal physical exam of the chest at admission, normal abdomen and pelvis physical exam at admission and absence of distracting lesions (Abbreviated Injury Scale >2 at skull, thorax and/or extremities). The ultrasound results were then studied in the group of patients with all clinical variables evaluated.

RESULTS

we studied 5536 victims of blunt trauma. Intra-abdominal lesions with AIS>1 were identified in 144 (2.6%); in patients with hemodynamic stability they were present in 86 (2%); in those with hemodynamic stability and normal neurological exam at admission in 50 (1.8%); in patients with hemodynamic stability and normal neurological and chest physical exam at admission, in 39 (1.5%); in those with hemodynamic stability, normal neurological, chest, abdominal and pelvic physical exam at admission, in 12 (0.5%); in patients with hemodynamic stability, normal neurological, chest, abdominal and pelvic physical exam at admission, and absence of distracting lesions, only two (0.1%) had intra-abdominal lesions. Among those with all clinical variables, 693 had normal total abdominal ultrasound, and, within this group, there were no identified intra-abdominal lesions.

CONCLUSION

when all clinical criteria and total abdominal ultrasound are associated, it is possible to identify a group of victims of blunt trauma with low chance of significant intra-abdominal lesions.

Variation in training and use of the focused assessment with sonography in trauma (FAST)

BACKGROUND

Training in ultrasound is variable among residents and practicing traumatologists. Focused Assessment with Sonography in Trauma (FAST) may be underused in non-urbanized areas, possibly due to lack of training.

METHODS

State trauma registry data from January 2014-June 2016 were reviewed for FAST results. Trauma practitioners were surveyed querying training, confidence, and obstacles to performing FAST.

RESULTS

12,855 records revealed highest FAST use at the urban Level II center (39%, p < 0.0001). Despite similar injury patterns, non-urban/Level III centers' frequency of FAST was only 1-28%. 39 practitioners were surveyed, those with training (54%) were more likely to use FAST (p < 0.05). 61% of practitioners outside the Level II center cited lack of confidence in their ability to perform FAST as the primary reason for omitting the exam.

CONCLUSIONS

FAST is relatively underused in non-urbanized areas of the state. Lack of confidence in ability to perform FAST was cited as the primary barrier.

Ten year maturation period in a level-I trauma center, a cohort comparison study

Purpose

Many changes have been made to improve trauma care. Improved trauma team response and usage of a hybrid resuscitation room are examples of how this trauma center has developed. The aim was to assess how the outcome of the trauma population was influenced by the maturation.

Methods

A cohort comparison, between June 2004–July 2005 and 2014, was performed. All adult trauma patients with an Injury Severity Score (ISS) >15 were included. Variables collected were: patient demographics, mechanism of trauma, total prehospital time, pre- and inhospital trauma scores, vital signs, blood values and interventions, and physician staffed helicopter emergency medical services (P-HEMS) involvement and outcome.

Results

From June 2004 to July 2005 219, patients were admitted, and for the year 2014, this was 282 patients. The 2014 cohort was significantly older (mean age of 53.6 ± 23.8 vs 45.6 ± 22.7 years). The mean RTS did not differ. P-HEMS assists increased to 116 (13.5 %). The number of CT scans, blood transfusion, and acute trauma surgical interventions decreased. Mean LOS, ICU admission, and ICU LOS did not differ. The mortality rate, however, decreased by 7.0 %, observed and predicted survival was significantly different in favour of the 2014 cohort, with a Z-score of 4.25.

Conclusion

An increase in age is seen, though trauma scores remain comparable. The number of blood products transfused and acute trauma surgical interventions performed declines. Mortality significantly decreased and a significant difference in observed and predicted survival is seen. Showing improved trauma care in our hospital, in favour of the second period.

Barriers Against Implementing Blunt Abdominal Trauma Guidelines in a Hospital: A Qualitative Study

Introduction

Clinical practice guidelines are structured recommendations that help physicians and patients to make proper decisions when dealing with a specific clinical condition. Because blunt abdominal trauma causes a various range of mild, single-system, and multisystem injuries, early detection will help to reduce mortality and resulting disability. Emergency treatment should be initiated based on CPGs. This study aimed to determine the variables affecting implementing blunt abdominal trauma CPGs in an Iranian hospital.

Methods

This study was conducted as a qualitative and phenomenology study in the Family Hospital in Tehran (Iran) in 2015. The research population included eight experts and key people in the area of blunt abdominal trauma clinical practice guidelines. Sampling was based on purposive and nonrandom methods. A semistructured interview was done for the data collection. A framework method was applied for the data analysis by using Atlas.ti software.

Results

After framework analyzing and various reviewing and deleting and combining the codes from 251 codes obtained, 15 families and five super families were extracted, including technical knowledge barriers, economical barriers, barriers related to deployment and monitoring, political will barriers, and managing barriers.

Conclusion

Structural reform is needed for eliminating the defects available in the healthcare system. As with most of the codes, subconcepts and concepts are classified into the field of human resources; it seems that the education and knowledge will be more important than other resources such as capital and equipment.

A 10-year restrospective evaluation of ultrasound in pregnant abdominal trauma patients

The pregnant abdominal trauma patient presents a unique diagnostic challenge. This study aimed to evaluate the accuracy of abdominal sonography for the detection of clinically important injuries in pregnant abdominal trauma patients. A retrospective review was performed of a trauma center database from 2001 to 2011. Medical records were reviewed to determine initial abdominal imaging test results and clinical course. Sensitivity, specificity, positive predictive value, and negative predictive value of ultrasound for detection of traumatic injury were calculated. Of 19,128 patients with suspected abdominal trauma, 385 (2 %) were pregnant. Of these, 372 (97 %) received ultrasound as the initial abdominal imaging test. All 13 pregnant patients who did not receive ultrasound received abdominal CT. Seven pregnant patients underwent both ultrasound and CT. Seven ultrasound examinations were positive, leading to one therapeutic Cesarean section and one laparotomy. One ultrasound was considered false positive (no injury was seen on subsequent CT). There were 365 negative ultrasound examinations. Of these, 364 were true negative (no abdominal injury subsequently found). One ultrasound was considered false negative (a large fetal subchorionic hemorrhage seen on subsequent dedicated obstetrical ultrasound). Sensitivity and positive predictive value were 85.7 %. Specificity and negative predictive value were 99.7 %. Abdominal sonography is an effective and sufficient imaging examination in pregnant abdominal trauma patients. When performed as part of the initial assessment using an abbreviated trauma protocol with brief modifications for pregnancy, ultrasound minimizes diagnostic delay, obviates radiation risk, and provides high sensitivity for injury in the pregnant population.