Serial abdominal ultrasound in the setting of trauma

Serial Trauma Abdominal Ultrasound in Children (STAUNCH): A Pilot Study

BACKGROUND

Ultrasound has established utility within pediatric emergency medicine and has an added benefit of avoiding excessive radiation exposure. The serial focused assessment with sonography in trauma (sFAST) examination is a potential alternative to improve pediatric trauma evaluation. We sought to evaluate the accuracy of sFAST in pediatric patients with blunt abdominal trauma.

METHODS

We performed a multicenter, retrospective observational study of electronic medical records, trauma registry data, and image archiving records of previous sFAST examinations. Examinations from pediatric patients (18 years or younger) who presented to an emergency department with blunt abdominal trauma were eligible for inclusion as long as the period between the first and second FAST was at least 30 minutes but no more than 24 hours. Demographic data and patient and outcomes were collected.

RESULTS

Data collected from 3 institutions found a total of 38 sFAST performed between July 2017 and September 2021 on eligible patients. Of these, there were 6 (15.4%) FAST examinations that were positive after an initial negative or indeterminate interpretation. The overall sensitivity and specificity of sFAST were 66.7% (95% confidence interval 22.3-95.7%) and 93.8% (79.2-99.3%), respectively.

CONCLUSIONS

This pilot study found that sFAST can enhance blunt trauma evaluation and improve sensitivity and diagnostic accuracy. More data are needed to determine how sFAST can be utilized in pediatric patients with blunt abdominal trauma.

False-positive focused abdominal sonography in trauma in a hypotensive child: case report

We report a case of a false-positive focused abdominal sonography in trauma (FAST) examination in a persistently hypotensive pediatric trauma patient, performed 12 hours after the trauma, suspected to be caused by massive fluid resuscitation leading to ascites. While a positive FAST in a hypotensive trauma patient usually indicates hemoperitoneum, this case illustrates that the timing of the FAST examination relative to the injury, as well as clinical evolution including the volume of fluid resuscitation, need to be considered when interpreting the results of serial and/or late FAST examinations.

The value of focused assessment with sonography in trauma examination for the need for operative intervention in blunt torso trauma: a rebuttal to “emergency ultrasound-based algorithms for diagnosing blunt abdominal trauma (review)”, from the Cochrane Collaboration

Background and significance

The Cochrane Database of Systematic Reviews published a manuscript critical of the use of the FAST examination. The reference is Stengel D. Bauwens K. Sehouli J. Rademacher G. Mutze S. Ekkernkamp A. Porzsolt F. Emergency ultrasound-based algorithms for diagnosing blunt abdominal trauma. Cochrane Database of Systematic Reviews. (2):CD004446, 2005. UI: 15846717. The stated objective was the assessment of the “efficiency and effectiveness” of ultrasound-inclusive evaluative algorithms in patients with suspected blunt abdominal trauma (BAT). The primary outcome measures explored were Mortality, CT and DPL use, and laparotomy rates. Little or no benefit was seen and the conclusion was that “there is insufficient evidence from randomized controlled trials to justify promotion” of FAST in patients with BAT. While the review used the same rigorous methods employed in all Cochrane Reviews, it appears that several serious flaws plagued the manuscript. The finest methodological rigor cannot yield usable results, if it is not applied to a clinically relevant question. In a world of increasingly conservative management of BAT, do we need FAST, a rapid, repeatable screening modality at the point-of-care to visualize any amount of free fluid or any degree of organ injury? The obvious answer is no. However, quantifying the value of FAST to predict the need for immediate operative intervention (OR) is essential.

Methods

To rebut this recurrent review, a systematic literature review was conducted using verbatim methodologies as described in the Cochrane Review with the exception of telephone contacts. Data were tabulated and presented descriptively.

Results

Out of 487 citations, 163 articles were fully screened, 11 contained prospectively derived data with FAST results, patient disposition and final diagnoses, and a description of cases considered false negatives or false positives. Of the 2,755 patients, 448 (16%) went to the OR. There were a total of 5 patients with legitimately false-negative diagnoses made based on the FAST: 3 involving inadequate scans and 2 of blunt trauma-induced small bowel perforations without hemoperitoneum.

Conclusion

The FAST examination, adequately completed, is a nearly perfect test for predicting a “Need for OR” in patients with blunt torso trauma.

Advances in Abdominal Trauma

Emergency practitioners routinely encounter patients who suffer from abdominal trauma, be it blunt or penetrating. These injuries are often confounded by altered mental status, distracting injuries, or lack of historical information, and may present challenges in management. However, in the last several years new approaches to the diagnosis and management of abdominal trauma, including bedside ultrasound, newer generation computed tomography scans, laparoscopy, and the ability for selected nonoperative management expedite identification of life threatening injury and offer new options in treatment.

Emergency diagnostic paracentesis to determine intraperitoneal fluid identity discovered on bedside ultrasound of unstable patients

Patients presenting with hypotension may be evaluated with a FAST (Focused Abdominal Sonography for Trauma) examination as recent literature has suggested its utility in the unstable patient. Those who are found to have intraperitoneal fluid on the FAST examination may have solid organ injury from unknown trauma, ruptured abdominal aortic aneurysm (AAA), hemorrhaging ovarian cyst, ruptured ectopic pregnancy, or other disease process responsible for intra-periteal blood. However, because ultrasound does not assist in fluid identification, it is possible that the fluid present is not blood, but ascites. Further, a decision may need to be made regarding emergent surgical intervention or blood transfusion vs. aggressive fluid resuscitation or pressors followed by other testing such as computed tomography. This case series illustrates the utility of an ultrasound guided, emergent diagnostic paracentesis in the management of unstable patients found to have a positive FAST examination. Six unstable patients were evaluated with the FAST examination and found to have large quantities of intraperitoneal fluid. In each case the fluid was sampled and proposed management changed due to fluid identification.

Major vascular injury after laparoscopic tubal ligation

Laparoscopy has become an established approach with diverse applications in both diagnostic and therapeutic surgical procedures. In general, the procedure is safe and effective and offers the advantage of being less invasive than conventional surgery. Complications after laparoscopy are uncommon but among them major vascular injury is potentially the most fatal, with recognition or mortality typically occurring intra-operatively or in the immediate post-operative period. We report the case of a delayed emergency department presentation of a major vascular injury after an elective laparoscopic tubal ligation. The prevalence, diagnosis, pathophysiolgy and management of major vascular injury after laparoscopic surgery is discussed.

Massive haemorrhage from hepatic laceration with diaphragmatic laceration: a potential limitation of the FAST examination: case report

This report describes the case of a multitrauma patient who had life-threatening intraabdominal hemorrhage with a diaphragmatic laceration. This hemorrhage remained undetected by serial focus assessment with sonography for trauma (FAST) examination. The potential for intraabdominal blood to move through a diaphragmatic laceration to the pleural space may limit the development of hemoperitoneum, rendering the FAST examination misleading or producing a false-negative result. The use of the FAST examination is discussed along with its advantages and limitations.

Focused assessment with sonography for trauma patients by clinicians: Initial experience and results

OBJECTIVES

To describe the establishment of a service to provide bedside focused assessment sonography in trauma and to evaluate the service to date.

SETTING

Emergency department of an urban trauma centre.

METHODS

A prospective study of trauma patients who received a focused assessment sonography in trauma examination performed by a clinician managing the trauma in the emergency department. Accuracy was determined by comparing the scan interpretation with abdomino-pelvic computerized tomography, laparotomy or postmortem examination.

RESULTS

The study period ran from 1 January 2000 to 11 September 2001 inclusive (20 months). One hundred and forty patients were included, with a final diagnosis established by computerized tomography (n = 124) and/or laparotomy (n = 18). There were 26 true-positives, 101 true-negatives, two false-positives and 11 false-negatives. Ten of the false-negative studies were performed by clinicians who had not reached accreditation. The sensitivity of focused assessment sonography in trauma was 70%, specificity 98% and diagnostic accuracy 91%.

CONCLUSIONS

We have described the implementation of a clinician-based focused assessment sonography in trauma service within the emergency department with the support of radiology/ultrasound and trauma service. Processes for credentialling, quality assurance and training need to be in place. Significant issues exist with the length of time it takes clinicians to reach accreditation, in order that a critical mass of clinicians exists to provide a consistent service. The credentialling process should mandate a minimum number of supervised examinations.

The focused abdominal sonography for trauma scan: pearls and pitfalls

OBJECTIVE

To review the state-of-the-art use of sonography in evaluating the patient with trauma.

METHODS

We reviewed our experience in performing more than 5000 sonographic examinations in the patient with trauma. The recent experience of other publications advocating newer applications of sonography in the patient with trauma are discussed and presented in a pictorial fashion.

RESULTS

The main focus of sonography in the patient with trauma has been in performance of the focused abdominal sonography for trauma scan. The focused abdominal sonography for trauma scan is usually performed in the patient with blunt abdominal trauma and is used to check for free fluid in the abdomen or pelvis. There are certain pitfalls that need to be avoided and certain limitations of the focused abdominal sonography for trauma scan that need to be recognized. These pitfalls and limitations are reviewed. More recently, sonography has been used to detect certain solid-organ injuries that have a variety of appearances. Thus, sonography may be used to localize the specific site of injury in these patients. More recently, sonography has been used to evaluate thoracic abnormalities in patients with trauma, including pleural effusions, pneumothoraces, and pericardial effusions.

CONCLUSIONS

The use of sonography in evaluating the patient with trauma has rapidly expanded in the past decade. Those using sonography in this group of patients should be aware of its many uses but also its potential pitfalls and limitations.

Significant hemoperitoneum in blunt trauma victims with normal vital signs and clinical examination

Clinical examination of the abdomen is generally reliable in stable trauma patients with no distracting or head injury. Patients involved in relatively minor trauma with normal examinations can be safely sent home in most instances. We report 6 cases of blunt abdominal trauma that had completely normal clinical examinations and vital signs but were found to have significant hemoperitoneum on trauma ultrasound examination. Four of the patients were examined for educational purposes just before planned discharge from the emergency department. These cases suggest that a screening ultrasound examination may have a role in the evaluation of most blunt trauma patients.

Blunt abdominal trauma in children: evaluation with emergency US

PURPOSE

To assess the accuracy of emergency abdominal ultrasonography (US) in the detection of both hemoperitoneum and parenchymal organ injury in children.

MATERIALS AND METHODS

Imaging findings were recorded prospectively in 744 consecutive children who underwent emergency US from January 1995 to October 1998; free fluid and parenchymal abnormalities of specific organs were also noted. Patients with intraabdominal injuries were identified retrospectively. Computed tomographic (CT) findings, intraoperative findings, and clinical outcome were compared with the initial US findings. Sensitivity, specificity, and positive and negative predictive values were calculated for patients who underwent CT, laparotomy, or both after US.

RESULTS

Seventy-five (10%) of 744 patients had intraabdominal injuries, and US depicted free fluid in 42 of them. US had 56% sensitivity, 97% specificity, 82% positive predictive value, and 91% negative predictive value for detection of hemoperitoneum alone. US helped identify parenchymal abnormalities that corresponded to actual organ injury without accompanying free fluid in nine patients (12%). Inclusion of identification of parenchymal organ injury at US increased the sensitivity of US to 68%, with an accuracy of 92%.

CONCLUSION

US for blunt abdominal trauma in children is highly accurate and specific, but moderately sensitive, for detection of intraabdominal injury.

Sonographic assessment of blunt abdominal trauma: a 4-year prospective study

PURPOSE

Emergency abdominal sonography has become a common modality worldwide in the evaluation of injuries caused by blunt trauma. The sensitivity of sonography in the detection of hemoperitoneum varies, and little is known about the accuracy of sonography in the detection of injuries to specific organs. The purpose of this study was to determine the overall accuracy of sonography in the detection of hemoperitoneum and solid-organ injury caused by blunt trauma.

METHODS

From January 1995 to October 1998, 3,264 patients underwent emergency sonography at our institution to evaluate for free fluid and parenchymal abnormalities of specific organs caused by blunt trauma. All patients with intra-abdominal injuries (IAIs) were identified, and their sonographic findings were compared with their CT and operative findings, as well as their clinical outcomes.

RESULTS

Three hundred ninety-six (12%) of the 3,264 patients had IAIs. Sonography detected free fluid presumed to represent hemoperitoneum in 288 patients (9%). The sonographic detection of free fluid alone had a 60% sensitivity, 98% specificity, 82% positive predictive value, and 95% negative predictive value for diagnosing IAI. The accuracy was 94%. Seventy patients (2%) had parenchymal abnormalities identified with sonography that corresponded to actual organ injuries. The sensitivity of the sonographic detection of free fluid and/or parenchymal abnormalities in diagnosing IAI was 67%.

CONCLUSIONS

Emergency sonography to evaluate patients for injury caused by blunt trauma is highly accurate and specific. The sonographic detection of free fluid is only moderately sensitive for diagnosing IAI, but the combination of free fluid and/or a parenchymal abnormality is more sensitive.

Penetrating stab wounds to the abdomen: use of serial US and contrast-enhanced CT in stable patients

PURPOSE

To evaluate the usefulness of computed tomography (CT) and ultrasonography (US) for the initial assessment of penetrating abdominal stab wounds in patients who presented to the emergency department without indication for immediate laparotomy.

MATERIALS AND METHODS

During 36 months, 32 patients with a penetrating stab wound to the abdomen were examined with serial US (at admission and 12 hours later) and helical CT, with contrast material administered orally, intravenously, and rectally. Presence of hemoperitoneum and integrity of solid and hollow viscera were evaluated with both methods. Sonograms were interpreted by the radiologist who performed the examination, and CT images were independently evaluated by two radiologists. Findings of both techniques were compared with clinical outcome and/or surgical findings.

RESULTS

One (3.1%) of 32 patients required surgery: Surgical findings were massive hemoperitoneum and an extensive hepatic laceration. Both US and CT depicted these abnormalities. Thirty-one (96.9%) patients were treated conservatively, without surgery, and remained asymptomatic during 28 days of clinical follow-up after discharge from the hospital. US and/or CT showed intraperitoneal abnormalities in 21 of these patients. In 11 patients, both methods showed no evidence of visceral injury or hemoperitoneum, and none of these patients required surgery.

CONCLUSION

Serial US and CT help guide treatment for stable patients with penetrating stab injuries to the abdomen.