Findings and limitations of focused ultrasound as a possible screening test in stable adult patients with blunt abdominal trauma: a Greek study

A porcine study of ultrasound-guided versus fluoroscopy-guided placement of endovascular balloons in the inferior vena cava (REBOVC) and the aorta (REBOA)

Objectives

In fluoroscopy-free settings, alternative safe and quick methods for placing resuscitative endovascular balloon occlusion of the aorta (REBOA) and resuscitative endovascular balloon occlusion of the inferior vena cava (REBOVC) are needed. Ultrasound is being increasingly used to guide the placement of REBOA in the absence of fluoroscopy. Our hypothesis was that ultrasound could be used to adequately visualize the suprahepatic vena cava and guide REBOVC positioning, without significant time-delay, when compared with fluoroscopic guidance, and compared with the corresponding REBOA placement.

Methods

Nine anesthetized pigs were used to compare ultrasound-guided placement of supraceliac REBOA and suprahepatic REBOVC with corresponding fluoroscopic guidance, in terms of correct placement and speed. Accuracy was controlled by fluoroscopy. Four intervention groups: (1) fluoroscopy REBOA, (2) fluoroscopy REBOVC, (3) ultrasound REBOA and (4) ultrasound REBOVC. The aim was to carry out the four interventions in all animals. Randomization was performed to either fluoroscopic or ultrasound guidance being used first. The time required to position the balloons in the supraceliac aorta or in the suprahepatic inferior vena cava was recorded and compared between the four intervention groups.

Results

Ultrasound-guided REBOA and REBOVC placement was completed in eight animals, respectively. All eight had correctly positioned REBOA and REBOVC on fluoroscopic verification. Fluoroscopy-guided REBOA placement was slightly faster (median 14 s, IQR 13-17 s) than ultrasound-guided REBOA (median 22 s, IQR 21-25 s, p=0.024). The corresponding comparisons of the REBOVC groups were not statistically significant, with fluoroscopy-guided REBOVC taking 19 s, median (IQR 11-22 s) and ultrasound-guided REBOVC taking 28 s, median (IQR 20-34 s, p=0.19).

Conclusion

Ultrasound adequately and quickly guide the placement of supraceliac REBOA and suprahepatic REBOVC in a porcine laboratory model, however, safety issues must be considered before use in trauma patients.

Level of evidence

Prospective, experimental, animal study. Basic science study.

Clinical Applications of B-Flow Ultrasound: A Scoping Review of the Literature

Coded excitation ultrasound investigations have the potential to augment the resolution, increase the efficiency, and expand the possibilities of noninvasive diagnostic imaging. B-Flow ultrasound, a type of digitally encoded imaging, was developed more than 20 years ago with the aim to optimize the visualization of blood flow. It has been investigated for a plethora of applications so far. A scoping review regarding its clinical applications was conducted based on a systematic literature research. B-Flow has been investigated in various anatomic locations and pathologies. However, previous research is limited by small sample sizes, the rare occurrence of elaborate study designs, the reliance on subjective reports and qualitative data, as well as several potential biases. While results are in general promising, it should therefore still be considered an emerging technology. Nevertheless, the limitations can be addressed in future research and the potential to expand its applications make B-Flow an interesting candidate for further investigations.

Lessons learned from blunt trauma abdomen: Surgical experience in level I trauma centre

Objective: The number of accident cases is increasing day by day, so as the challenges. With an emphasis on trauma care, the government started a 120 bedded level I trauma centre in northern India catering to a population of 2.8 million in June 2018. Through this article, we aimed to share our experience of blunt abdominal trauma management from a new level I trauma centre.

Material and Methods: In this retrospective observational study, historical analysis of all available records from July 2018 to March 2020 was done. Inclusion criteria included blunt trauma abdomen with or without associated injuries. Data regarding age, sex, mechanism of injury, time taken to reach the hospital, the pattern of solid organs and hollow viscus injuries, associated extra abdominal injuries, mode of treatment, complications, length of ICU and hospital stay, and mortality were reviewed.

Results: Overall, 154 cases sustained abdominal injuries during the study period. Seventy-five percent were male. The most common cause of blunt trauma abdomen was road traffic crashes. Operative management was required in 57 (37.01%) cases while 97(62.98%) were managed non-operatively (NOM). Mean ICU stay was 05.73 days, while the average hospital stay was 12 days (range 10-60 days). Procedures performed included splenectomy, liver repair, primary closure of bowel injury, and stoma formation. Complications occured in 16.88% cases and the overall mortality rate was 11.68%.

Conclusion: The study revealed that among 154 cases of fatal blunt abdominal trauma, road traffic crash was the most common cause of blunt abdominal trauma, predominantly affecting males. The visceral and peritoneal injury frequently perceived was liver in 40 cases (25.9%), spleen 66 (43%), intestine 21(13.6%) and kidney 13 cases (09%). Abdominal injury was associated with other injuries like head, chest and extremity injuries in 52.5% cases. Duration of injury, presence of associated injury and preoperative ventilation requirement were independent predictors of mortality apart from contributary factors such as clinical presentation, organ involved and presence of complications.

Emergency Focused Assessment with Sonography in Blunt Trauma Abdomen

Background:

Focused assessment with sonography in trauma (FAST) being a rapid noninvasive examination is used primarily to evaluate for the evidence of traumatic free fluid suggestive of injury in the peritoneal, pericardial, and pleural cavities. It is widely recognized as a mainstream emergency skill in the management of trauma.

Aim:

The aim of the study is to evaluate the accuracy of FAST in patients presenting with blunt abdominal trauma.

Methods:

Data were collected prospectively from FAST scans conducted in blunt trauma abdomen (BTA) patients. Positive and negative FAST scans were confirmed either with contrast-enhanced computed tomography (CECT) abdomen or with exploratory laparotomy, thus dividing it further into four groups, i.e., true-positive, false-positive, true-negative, and false-negative scans. After collecting the data, accuracy of FAST was calculated.

Results:

In this study, a total of 104 patients were included. The mean age was 38.17 years. Most common cause of BTA was road traffic accident. The overall sensitivity, specificity, and accuracy of FAST were 69.8%, 92.1%, and 80.8%, respectively.

Conclusion:

This study showed that FAST is of paramount importance in patients who are hemodynamically unstable as it has a high positive predictive value. However, a FAST-negative result should always be confirmed by other modalities.

Focused assessment with sonography for trauma: current perspectives

Focused assessment with sonography for trauma (FAST) is a part of resuscitation of trauma patients recommended by international panel consensus. The purpose of FAST is to identify free fluid, which necessarily means blood in acute trauma patients. In this article, the authors focused on various aspects of FAST in the emergency department, prehospital care, pediatric setting, training and general pearls/pitfalls. Detailed techniques and interpretation of FAST are beyond the scope of this article.

Diagnostic accuracy of emergency-performed focused assessment with sonography for trauma (FAST) in blunt abdominal trauma

Introduction

Intra-abdominal hemorrhage due to blunt abdominal trauma is a major cause of trauma-related mortality. Therefore, any action taken for facilitating the diagnosis of intra-abdominal hemorrhage could save the lives of patients more effectively. The aim of this study was to determine the accuracy of focused assessment with sonography for trauma (FAST) performed by emergency physicians.

Methods

In this cross-sectional study from February 2011 to January 2012 at 7^th Tir Hospital in Tehran (Iran), 120 patients with abdominal blunt trauma were chosen and evaluated for abdominal fluid. FAST sonography was performed for all the subjects by emergency residents and radiologists while they were blind to the other tests. Abdominal CTs, which is the gold standard, were done for all of the cases. SPSS 20.0 was used to analyze the results.

Results

During the study, 120 patients with abdominal blunt trauma were evaluated; the mean age of the patients was 33.0 ± 16.6 and the gender ratio was 3/1 (M/F). The results of FAST sonography by emergency physicians showed free fluid in the abdomen or pelvic spaces in 33 patients (27.5%), but this was not observed by the results of CT scans of six patients; sensitivity and specificity were 93.1 and 93.4%, respectively. As for tests performed by radiology residents, sensitivity was a bit higher (96.5%) with lower specificity (92.3%).

Conclusion

The results suggested that emergency physicians can use ultrasonography as a safe and reliable method in evaluating blunt abdominal trauma.

Relationship between Obesity and Massive Transfusion Needs in Trauma Patients, and Validation of TASH Score in Obese Population: A Retrospective Study on 910 Trauma Patients

Background

Prediction of massive transfusion (MT) is challenging in management of trauma patients. However, MT and its prediction were poorly studied in obese patients. The main objective was to assess the relationship between obesity and MT needs in trauma patients. The secondary objectives were to validate the Trauma Associated Severe Hemorrhage (TASH) score in predicting MT in obese patients and to use a grey zone approach to optimize its ability to predict MT.

Methods and Findings

An observational retrospective study was conducted in a Level I Regional Trauma Center Trauma in obese and non-obese patients. MT was defined as ≥10U of packed red blood cells in the first 24h and obesity as a BMI≥30kg/m². Between January 2008 and December 2012, 119 obese and 791 non-obese trauma patients were included. The rate of MT was 10% (94/910) in the whole population. The MT rate tended to be higher in obese patients than in non-obese patients: 15% (18/119, 95%CI 9‒23%) versus 10% (76/791, 95%CI 8‒12%), OR, 1.68 [95%CI 0.97‒2.92], p = 0.07. After adjusting for Injury Severity Score (ISS), obesity was significantly associated with MT rate (OR, 1.79[95%CI 1.00‒3.21], p = 0.049). The TASH score was higher in the obese group than in the non-obese group: 7(4–11) versus 5(2–10)(p<0.001). The area under the ROC curves of the TASH score in predicting MT was very high and comparable between the obese and non-obese groups: 0.93 (95%CI, 0.89‒0.98) and 0.94 (95%CI, 0.92‒0.96), respectively (p = 0.80). The grey zone ranged respectively from 10 to 13 and from 9 to 12 in obese and non obese patients, and allowed separating patients at low, intermediate or high risk of MT using the TASH score.

Conclusions

Obesity was associated with a higher rate of MT in trauma patients. The predictive performance of the TASH score and the grey zones were robust and comparable between obese and non-obese patients.

The Face, Content, and Construct Validity Assessment of a Focused Assessment in Sonography for Trauma Simulator

OBJECTIVE

Hemorrhage identification in trauma care is a major priority. Focused assessment in sonography for trauma (FAST) offers a rapid, reliable means of detecting torso bleeding. The aims of this study were to conduct a face, content, and construct validity assessment of a FAST simulator and establish a rigorous assessment tool.

DESIGN

Participants were requested to perform a FAST scan and state if any abnormality was found in each region. Metrics evaluated included time, errors, and missed targets. Accuracy of images obtained was assessed by 2 independent radiologists. Experts completed a face and content validity questionnaire at the end of the study.

SETTING

The study took place in the simulation suite within the Academic Surgical Unit of the Department of Surgery and Cancer.

PARTICIPANTS

Novices had no prior experience with ultrasound, intermediates had less than 6 months experience with fewer than 50 FAST scans performed, and experts had more than 1 year of experience with greater than 100 FAST scans performed. There were 31 participants: 11 experts, 10 intermediates, and 10 novices.

RESULTS

The face and content validity questionnaire scored high marks across all categories and achieved an overall median realism score of 8 ± 1.5 on a Likert scale. Experts performed the FAST scan faster with more accuracy and fewer errors than other cohorts (p < 0.001). Both the novices and intermediates were the slowest, least accurate, and either missed or made the most errors when scanning the lung bases and spleen.

CONCLUSIONS

This study has established the face, content, and construct validities of a FAST simulator, which could be used to accelerate training for novices. Additionally, it has demonstrated a rigorous method for FAST assessment, which has proven to be effective and in doing so addressed some of the criticisms leveled against it.

Do we really rely on fast for decision-making in the management of blunt abdominal trauma?

INTRODUCTION

The Focused Assessment with Sonography in Trauma examination (FAST) is currently taught and recommended in the ATLS(®), often as an addendum to the primary survey for patients with blunt abdominal trauma. Although it is non-invasive and rapidly performed at bedside, the utility of FAST in blunt abdominal trauma has been questioned. We designed this study to examine our hypothesis that FAST is not an efficacious screening tool for identifying intra-abdominal injuries.

METHODS

We performed a retrospective chart review of all patients with confirmatory diagnosis of blunt abdominal injuries with CT and/or laparotomy for a period of 1.5 years (from 7/2009 to 11/2010). FAST was performed by ED residents and considered positive when free intra-abdominal fluid was visualized. Abdominal CT, or exploratory laparotomy findings were used as confirmation of intra-abdominal injury.

RESULTS

A total of 1671 blunt trauma patients were admitted to and evaluated in the Emergency Department during a 1½ year period and 146 patients were confirmed intra-abdominal injuries by CT and/or laparotomy. Intraoperative findings include injuries to the liver, spleen, kidneys, and bowels. In 114 hemodynamically stable patients, FAST was positive in 25 patients, with a sensitivity of 22%. In 32 hemodynamically unstable patients, FAST was positive in 9 patients, with a sensitivity of 28%. A free peritoneal fluid and splenic injury are associated with a positive FAST on univariate analysis, and are the independent predictors for a positive FAST on multiple logistic regression.

CONCLUSION

FAST has a very low sensitivity in detecting blunt intraabdominal injury. In hemodynamically stable patients, a negative FAST without a CT may result in missed intra-abdominal injuries. In hemodynamically unstable blunt trauma patients, with clear physical findings on examination, the decision for exploratory laparotomy should not be distracted by a negative FAST.

The use of contrast-enhanced ultrasound in blunt abdominal trauma: advantages and limitations

Computed tomography (CT) is the imaging method of choice in the assessment of multiple trauma patients. However, in patients who suffered from low-energy abdominal trauma, the use of CT is controversial, since the probability of injury is low and therefore most of the studies are normal. Thus, conventional US imaging has increasingly been employed as the initial imaging modality in the work-up of minor traumatic emergency condition. More recently, the introduction of a new contrast-enhanced ultrasound (CEUS) technique, using second-generation ultrasound contrast agents, has led to a notable increase in the diagnostic accuracy of US in many organs. Therefore, in trauma patients, following assessment with conventional US imaging, a CEUS exam can be performed, to provide a more reliable assessment of solid organ injuries. CEUS has the potential to detect active bleeding from a variety of traumatic origins. Similar to CT, active extravasation is considered when there is evidence of contrast agent collection with echogenicity similar to that of an adjacent vessel. On the other hand, at least some drawbacks have to be addressed, including operator competence and reduced panoramic view. Moreover, CEUS, like conventional US imaging, cannot depict some lesions, such as diaphragmatic ruptures, bowel, and mesenteric traumatic injuries. This technique represents a non-invasive and repeatable method that can be performed at patient's bedside and is therefore extremely helpful for the follow-up of solid organs traumas managed conservatively, especially in pediatric patients and women of fertile age. Moreover, it may reduce the number of CT scans and expedite patient discharge.

Identificação de lesões abdominais graves na avaliação inicial das vítimas de trauma fechado

OBJETIVO: avaliar os fatores preditivos de lesões abdominais graves (LAG) identificáveis na avaliação inicial das vítimas de trauma fechado. MÉTODOS: análise retrospectiva dos dados das vítimas de trauma fechado com idade superior a 13 anos submetidas à tomografia computadorizada do abdome e/ou laparotomia exploradora. Consideramos como graves as lesões com Abbreviated Injury Scale (AIS) maior ou igual a três. As variáveis foram comparadas entre os grupos A (LAG) e B (Sem LAG). Realizou-se inicialmente uma análise estatística univariada para identificar as variáveis associadas à presença de LAG. Destas, foram selecionadas para a análise multivariada (regressão logística) as que tivessem p<0,20 e pudessem ser avaliadas na admissão do doente. RESULTADOS: a amostra foi composta por 331 casos, sendo que 140 (42,3%) pacientes apresentaram lesões abdominais. Destes, 101 (30,5%) tinham lesão abdominais com AIS > 3 (Grupo A). Na análise univariada, associaram-se significativamente às LAG (p<0,05): pressão arterial sistólica (PAS) no pré-hospitalar (p=0,019), PAS à admissão (p<0,001), frequência cardíaca à admissão (p=0,047), exame físico do abdome alterado (p<0,001) e presença de fraturas de pelve (p=0,006). As seguintes variáveis se relacionaram significativamente e independentemente com a presença de lesões abdominais graves: PAS à admissão (p=0,034), exame físico abdominal alterado (p<0,001), fratura exposta de membro inferior (p<0,044), "motociclista" como mecanismo de trauma (p=0,017) e FAST positivo (p<0,001). CONCLUSÃO: das variáveis presentes na avaliação inicial, se associaram significativamente com a presença de LAG: PAS, exame físico abdominal alterado, presença de fratura exposta de membro inferior, "motociclista" como mecanismo de trauma e FAST positivo.

Sonographic assessment of a suspected biloma: A case report and review of the literature

A biloma is a rare disease characterized by an abnormal intra- or extrahepatic bile collection due to a traumatic or spontaneous rupture of the biliary system. Laboratory findings are nonspecific. The diagnosis is usually suspected on the basis of a typical history (right upper quadrant abdominal pain, chills, fever and recent abdominal trauma or surgery) and is confirmed by detection of typical radiologic features. We report the case of a patient with a history of previous cholecystectomy for lithiasis who presented with clinical symptoms and laboratory data suggestive of acute pancreatitis. Imaging studies also revealed the presence of a chronic and asymptomatic biloma, which could be mistaken for a pseudocyst. The atypical location and ultrasound findings suggested an alternative diagnosis. We therefore reviewed the known literature for bilomas, focusing on the role of ultrasonography, which can reveal some typical aspects, such as location and imaging features. We conclude that ultrasound plays a key role in the assessment of a suspected biloma in patients with appropriate history and clinical features and provides valuable diagnostic clues even in the absence of these.

Predictors of abdominal injuries in blunt trauma

OBJECTIVE

To identify predictors of abdominal injuries in victims of blunt trauma.

METHOD

retrospective analysis of trauma protocols (collected prospectively) of adult victims of blunt trauma in a period of 15 months. Variables were compared between patients with abdominal injuries (AIS>0) detected by computed tomography or/and laparotomy (group I) and others (AIS=0, group II). Student's t, Fisher and qui-square tests were used for statistical analysis, considering p<0.05 as significant.

RESULTS

A total of 3783 cases were included, with a mean age of 39.1 ± 17.7 years (14-99), 76.1% being male. Abdominal injuries were detected in 130 patients (3.4%). Patients sustaining abdominal injuries had significantly lower mean age (35.4 + 15.4 vs. 39.2 + 17.7), lower mean systolic blood pressure on admission (114.7 + 32.4 mmHg vs. 129.1 + 21.7 mmHg), lower mean Glasgow coma scale (12.9 + 3.9 vs. 14.3 + 2.0), as well as higher head AIS (0.95 + 1.5 vs. 0.67 + 1.1), higher thorax AIS (1.10 + 1.5 vs. 0.11 + 0.6) and higher extremities AIS (1.70 ± 1.8 vs. 1.03 ± 1.2). Patients sustaining abdominal injuries also presented higher frequency of severe injuries (AIS>3) in head (18.5% vs. 7.9%), thorax (29.2% vs. 2.4%) and extremities (40.0% vs. 13.7%). The highest odds ratios for the diagnosis of abdominal injuries were associated flail chest (21.8) and pelvic fractures (21.0).

CONCLUSION

Abdominal injuries were more frequently observed in patients with hemodynamic instability, changes in Glasgow coma scale and severe lesions to the head, chest and extremities.

[How should anesthesiologists perform ultrasound examinations? Diagnostic use of ultrasound in emergency and intensive care and medicine]

Ultrasound imaging has attained great significance as a tool for diagnostics in emergency and intensive care medicine. The major advantages of this technique are its instantaneous bedside availability and the possibility to perform repeatable examinations. These advantages are based on recent developments, such as portable ultrasound devices offering excellent imaging quality as well as a quick-start-function. Ultrasound imaging in critically ill patients is frequently performed under pressure of time depending on the current acute physical state. All standard examinations in echocardiography, vascular, abdominal and thoracic ultrasound scanning can be applied in these patients. Based on the clinical scenario the duration of examinations may vary from seconds during cardiopulmonary resuscitations to time-consuming repeated scanning. The transition from basic to subject-specific detailed examinations is flowing and has to be adjusted to local conditions. In the field of emergency and intensive care medicine the technique used is whole-body sonography. The goal is to classify the patient's present physical state and to define a targeted therapeutic approach. The characteristics of whole-body sonography are similar to the field of anesthesiology which is an interdisciplinary one. Currently, these characteristics deserve more attention in training in sonography.

FAST scan: is it worth doing in hemodynamically stable blunt trauma patients?

BACKGROUND

During the last decade, focused assessment with sonography for trauma increasingly has become the initial diagnostic modality of choice in trauma patients. It is still questionable, however, whether its use results in the underdiagnosis of intra-abdominal injury. It also remains doubtful whether a positive focused assessment with sonography for trauma affects clinical decision making in hemodynamically stable blunt trauma patients as evidenced through abdominal computerized tomography use. The aim of this study was to evaluate the results of focused assessment with sonography for trauma in hemodynamically stable blunt trauma patients and to determine its role in the diagnostic evaluation of these patients.

METHODS

We reviewed our prospectively maintained trauma database. In trauma patients at our institute, focused assessment with sonography for trauma examinations are performed by surgery residents and are considered positive when free intra-abdominal fluid is visualized. Abdominal computerized tomography, diagnostic peritoneal lavage, or exploratory laparotomy findings were used as confirmation of intra-abdominal injury.

RESULTS

In our 7-year study period, 2,980 trauma patients were evaluated at our institute, of which 2,130 patients underwent a focused assessment with sonography for trauma. In all, 18 patients had an inconclusive focused assessment with sonography for trauma, whereas 7 patients died on arrival, leaving 2,105 patients for our analysis. A total 88 true positive focused assessment with sonography for trauma were conducted. All hemodynamically stable blunt trauma patients who had a positive focused assessment with sonography for trauma (70/88) were confirmed by computerized tomography. Patients who underwent exploratory laparotomy directly (17/88) or diagnostic peritoneal lavage (1/88) as confirmation either had penetrating trauma or became hemodynamically unstable. A total of 1,894 true negative focused assessments with sonography for trauma scans were conducted, with 1,201 confirmed by computerized tomography and the rest by observation. In all, 118 false negative focused assessment with sonography for trauma were performed, of which 44 (37.3%) subsequently required exploratory laparotomy. Five patients had false positive focused assessment with sonography for trauma scans. Focused assessment with sonography for trauma scan had an overall sensitivity of 43%, a specificity of 99%, and positive and negative predictive values of 95% and 94%, respectively. Accuracy was 94.1%. In the hemodynamically stable blunt trauma group, there were 60 patients with true positive focused assessment with sonography for trauma examinations and 87 patients with false negative focused assessment with sonography for trauma examinations. In this group of patients, focused assessment with sonography for trauma had a sensitivity of 41%, specificity of 99%, and positive and negative predictive values of 94% and 95%, respectively. The overall accuracy was 95%.

CONCLUSION

Given the low sensitivity, a negative focused assessment with sonography for trauma without confirmation by computerized tomography may result in missed intra-abdominal injuries. It is also observed in all focused assessment with sonography for trauma positive hemodynamically stable blunt trauma patients, confirmation is preferred through the use of a computerized tomography for better understanding of the intra-abdominal injuries and to decide on operative versus no-operative management. Thus, the use of focused assessment with sonography for trauma in hemodynamically stable blunt trauma patients seems not worthwhile. It should be reserved for hemodynamically unstable patients with blunt trauma.