The indeterminate abdominal sonogram in multisystem blunt trauma

Ultrasonography in thoracic and abdominal stab wound injury: results from the FETTHA study

BACKGROUND

While the role of Extended Focused Assessment with Sonography in Trauma (eFAST) is well defined in the management of severe blunt trauma, its performance in injuries caused by stab wounds has been poorly assessed.

METHODS

Prospective single centre study which included all patients with stab wounds to the thorax or abdomen between December 2016 and December 2018. All patients underwent initial investigation with both eFAST and CT scan, except in cases of haemodynamic or respiratory instability, and in cases with a positive diagnosis by eFAST in which case surgery without CT scan was performed.

RESULTS

Of the 200 consecutive patients included, 14 unstable patients underwent surgery immediately after eFAST. In these 14 patients, 9 had cardiac tamponade identified by eFAST and all were confirmed by surgery. In the remaining 186 patients, the median time between eFAST and CT scan was 30 min (IQR 20-49 min). Test characteristics (including 95% CI) for eFAST compared with reference standard of CT scan for detecting pneumothorax were as follows: sensitivity 77% (54%-92%), specificity 93% (90%-97%), positive predictive value (PPV) 60% (49%-83%), negative predictive value (NPV) 97% (93%-99%). Test characteristics (including 95% CI) for eFAST compared with CT scan for detecting haemothorax were as follows: sensitivity 97% (74%-99%), specificity 96% (92%-98%), PPV 83% (63%-93%) and NPV 99% (96%-100%). Finally, test characteristics (including 95% CI) for eFAST compared with CT scan for detecting haemoperitoneum were as follows: sensitivity 75% (35%-97%), specificity 97% (93%-99%), PPV 55% (23%-83%) and NPV 99% (96%-99%).

CONCLUSIONS

In patients admitted with stab wounds to the torso, eFAST was not sensitive enough to diagnose pneumothorax and haemoperitoneum, but performed better in the detection of cardiac tamponade and haemothorax than the other injuries. More robust multicentre studies are needed to better define the role of eFAST in this specific population.

The Dangers of Equivocal FAST in Trauma Resuscitation

Equivocal focused abdominal sonography for trauma (FAST) examinations confound decision-making for trauma surgeons. We sought to determine whether the equivocal FAST (defined as any nonconcordant result) has a deleterious effect on trauma outcomes. A 2-year review (2014–2015) of all trauma activations at our Level I trauma center was performed. Patients were matched at baseline and FAST results were compared. Outcomes included resuscitation time (h), ventilation days (d), hospital length of stay (HLOS-d), ICU length-of-stay, and survival (%). In addition, skill level of the sonographer was stratified by novice (postgraduate year (PGY) years 1–3) or expert skill levels (PGY-4/fellow or attending). A total of 1,027 patients were included. Compared with concordant FAST examinations, equivocal FASTs were associated with increased HLOS (14.1 vs 10.6, P = 0.05), higher mortality (9.8 vs 3.7%, P = 0.02), decreased positive predictive value in the right upper quadrant (RUQ) (55 vs 79%, P = 0.02) and left upper quadrant (LUQ) (50 vs 83%, P < 0.01) and significantly decreased specificity in the thoracic (83 vs 98%), RUQ (80 vs 98%), LUQ (86 vs 99%), and pelvic (88 vs 98%) windows (P < 0.01 for all). A trend of greater positive predictive value in the thoracic window (100 vs 81%, P = 0.09) among PGY-4/fellow and attending providers compared with PGY levels 1–3 was observed. Equivocal FASTs portend worse outcomes than concordant FASTs because of high false-negative rates, specifically in the thoracic region and the upper quadrants. Lower thresholds for intervention are recommended.

The early management of gunshot wounds Part II: the abdomen, extremities and special situations

The management of gunshot wounds of the abdomen and extremities is evolving with centres who treat large volumes of such injuries tending to the application of a policy of selective non-operative management. This article discusses the management of gunshot wounds to the abdomen and extremities and reviews the evidence supporting these changing practices. Special situations such as wounding by shotguns or air rifles are also examined as are the special considerations needed when dealing with the gunshot injured pregnant women or in a child.

Help is in your pocket: the potential accuracy of smartphone- and laptop-based remotely guided resuscitative telesonography

BACKGROUND

Ultrasound (US) examination has many uses in resuscitation, but to use it to its full effectiveness typically requires a trained and proficient user. We sought to use information technology advances to remotely guide US-naive examiners (UNEs) using a portable battery-powered tele-US system mentored using either a smartphone or laptop computer.

MATERIALS AND METHODS

A cohort of UNEs (5 tactical emergency medicine technicians, 10 ski-patrollers, and 4 nurses) was guided to perform partial or complete Extended Focused Assessment with Sonography of Trauma (EFAST) examinations on both a healthy volunteer and on a US phantom, while being mentored by a remote examiner who viewed the US images over either an iPhone(®) (Apple, Cupertino, CA) or a laptop computer with an inlaid depiction of the US probe and the "patient," derived from a videocamera mounted on the UNE's head. Examinations were recorded as still images and over-read from a Web site by seven expert reviewers (ERs) (three surgeons, two emergentologists, and two radiologists). Examination goals were to identify lung sliding (LS) documented by color power Doppler (CPD) in the human and to identify intraperitoneal (IP) fluid in the phantom.

RESULTS

All UNEs were successfully mentored to easily and clearly identify both LS (19 determinations) and IP fluid (14 determinations), as assessed in real time by the remote mentor. ERs confirmed IP fluid in 95 of 98 determinations (97%), with 100% of ERs perceiving clinical utility for the abdominal Focused Assessment with Sonography of Trauma. Based on single still CPD images, 70% of ERs agreed on the presence or absence of LS. In 16 out of 19 cases, over 70% of the ERs felt the EFAST exam was clinically useful.

CONCLUSIONS

UNEs can confidently be guided to obtain critical findings using simple information technology resources, based on the receiving/transmitting device found in most trauma surgeons' pocket or briefcase. Global US mentoring requires only Internet connectivity and initiative.

Portable bedside ultrasound: the visual stethoscope of the 21st century

Over the past decade technological advances in the realm of ultrasound have allowed what was once a cumbersome and large machine to become essentially hand-held. This coupled with a greater understanding of lung sonography has revolutionized our bedside assessment of patients. Using ultrasound not as a diagnostic test, but instead as a component of the physical exam, may allow it to become the stethoscope of the 21st century.

Clinician performed resuscitative ultrasonography for the initial evaluation and resuscitation of trauma

BACKGROUND

Traumatic injury is a leading cause of morbidity and mortality in developed countries worldwide. Recent studies suggest that many deaths are preventable if injuries are recognized and treated in an expeditious manner - the so called 'golden hour' of trauma. Ultrasound revolutionized the care of the trauma patient with the introduction of the FAST (Focused Assessment with Sonography for Trauma) examination; a rapid assessment of the hemodynamically unstable patient to identify the presence of peritoneal and/or pericardial fluid. Since that time the use of ultrasound has expanded to include a rapid assessment of almost every facet of the trauma patient. As a result, ultrasound is not only viewed as a diagnostic test, but actually as an extension of the physical exam.

METHODS

A review of the medical literature was performed and articles pertaining to ultrasound-assisted assessment of the trauma patient were obtained. The literature selected was based on the preference and clinical expertise of authors.

DISCUSSION

In this review we explore the benefits and pitfalls of applying resuscitative ultrasound to every aspect of the initial assessment of the critically injured trauma patient.

Diagnostic peritoneal lavage and ultrasonography for blunt abdominal trauma: attitudes and training of current general surgical trainees

OBJECTIVE

It has been suggested that diagnostic peritoneal lavage is now obsolete in UK hospitals with access to either skilled ultrasonography or emergency physician or surgeon-performed focused abdominal sonography in trauma. Diagnostic peritoneal lavage continues to be advocated and taught on Advanced Trauma Life Support courses. The aim of this study was to evaluate the experiences and attitudes of general-surgery trainees in one UK training region towards diagnostic peritoneal lavage and focused abdominal sonography in trauma in managing blunt abdominal trauma.

METHODS

An anonymous postal piloted questionnaire was sent to all 66 general surgery specialist trainees in one UK training region between January and March 2005.

RESULTS

Out of 40 replies to the questionnaire (response rate 61%), 53% and 38% of surgical trainees had either never performed or never observed a diagnostic peritoneal lavage during their training. Thirteen trainees (33%) felt diagnostic peritoneal lavage to be obsolete and would never contemplate using it; 15 trainees (37%) might consider using diagnostic peritoneal lavage if computed tomography or ultrasonography were unavailable. Ten trainees (25%) felt that diagnostic peritoneal lavage had been superseded by computed tomography. Only 12 trainees (30%) had worked in a UK hospital with access to facilities for focused abdominal sonography in trauma and only seven trainees (18%) had received any training or experience in focused abdominal sonography in trauma.

CONCLUSIONS

Surgical trainees in one UK training region lack skills in both diagnostic peritoneal lavage and focused abdominal sonography in trauma for managing blunt abdominal trauma and are therefore reliant upon the availability of prompt, skilled radiological assistance or emergency physician-provided focused abdominal sonography in trauma.

Clinician-performed focused sonography for the resuscitation of trauma

Traumatic death remains pandemic. The majority of preventable deaths occur early and are due to injuries or physiologic derangements in the airway, thoracoabdominal cavities, or brain. Ultrasound is a noninvasive and portable imaging modality that spans a spectrum between the physical examination and diagnostic imaging. It allows trained examiners to immediately confirm important syndromes and answer clinical questions. Newer technologies greatly increase the fidelity, accessibility, ease of use, and informatic manipulation of the results. The early bedside use of focused ultrasound as the initial imaging modality used to detect hemoperitoneum and hemopericardium in the resuscitation of the injured patient has become an accepted standard of care. Widespread dissemination of basic ultrasound skills and technology to facilitate this brings ultrasound to many resuscitative and critical care areas. Although not as widely appreciated, the focused use of ultrasound may also have a role in detecting hemothoraces and pneumothoraces, guiding airway management, and detecting increased intracranial pressure. Intensivists generally utilize a treating philosophy that requires the real-time integration of many divergent sources of information regarding their patients' anatomy and physiology. They are therefore positioned to take advantage of focused resuscitative ultrasound, which offers immediate diagnostic information in the early care of the critically injured.

Prospective Study to Evaluate the Influence of FAST on Trauma Patient Management

BACKGROUND

Previous studies have concentrated on the accuracy of Focused Assessment with Sonography in Trauma (FAST), but evaluation of whether FAST changes subsequent management has not been fully assessed.

METHODS

This prospective study compared 419 trauma admissions in two groups, FAST and no-FAST, for demographics, time of resuscitation, and action after resuscitation. The 194 patients undergoing FAST had their management plan specified before, and confirmed after, FAST was performed to assess for change in management. To ensure scan consistency and to minimize bias, criteria were established to define an adequate FAST.

RESULTS

FAST was performed in 194 patients (46%), assessing for free fluid. Management was changed in 59 cases (32.8%) after FAST. Laparotomy was prevented in 1 patient, computed tomography was prevented in 23 patients, and diagnostic peritoneal lavage was prevented in 15 patients. Computed tomography rates were reduced from 47% to 34% and diagnostic peritoneal lavage rates were reduced from 9% to 1%.

CONCLUSIONS

FAST plays a key role in trauma, changing subsequent management in an appreciable number of patients.

Unnecessary laparotomy by using physical examination and different diagnostic modalities for penetrating abdominal stab wounds

BACKGROUND

The modern management of penetrating abdominal trauma has decreased the incidence of unnecessary laparotomy by using selective non-operative management protocols. However, the real benefits of physical examination and different diagnostic methods are still unclear.

METHODS

From January 2000 to April 2003, we prospectively collected data on 117 patients with penetrating stab wounds to the thoracoabdominal, anterior abdominal, and back regions who had non-operative management. Clinical examination was the primary tool to differentiate those patients requiring operation. Findings of physical examination, ultrasound, computed tomography, endoscopy, echocardiography, diagnostic peritoneal lavage, and diagnostic laparoscopy were reviewed. The number of therapeutic, non-therapeutic, and negative laparotomies were recorded.

RESULTS

Non-operative management was successful in 79% of patients. There were 11 early (within 8 hours of admission) and 14 delayed (more than 8 hours after admission) laparotomies performed, depending on the results of various diagnostic procedures. Non-operative management failed in 21% of patients, and the rate of non-therapeutic laparotomy in early and delayed laparatomy groups was 9% and 14% respectively. There was no negative laparatomy.

CONCLUSIONS

The use of physical examination alone and/or together with different diagnostic methods allows reduction of non-therapeutic laparotomies and elimination of negative laparatomies.

Thoracic sonography for pneumothorax: the clinical evaluation of an operational space medicine spin-off

The recent interest in the use of ultrasound (US) to detect pneumothoraces after acute trauma in North America was initially driven by an operational space medicine concern. Astronauts aboard the International Space Station (ISS) are at risk for pneumothoraces, and US is the only potential medical imaging available. Pneumothoraces are common following trauma, and are a preventable cause of death, as most are treatable with relatively simple interventions. While pneumothoraces are optimally diagnosed clinically, they are more often inapparent even on supine chest radiographs (CXR) with recent series reporting a greater than 50% rate of occult pneumothoraces. In the course of basic scientific investigations in a conventional and parabolic flight laboratory, investigators familiarized themselves with the sonographic features of both pneumothoraces and normal pulmonary ventilation. By examining the visceral-parietal pleural interface (VPPI) with US, investigators became confident in diagnosing pneumothoraces. This knowledge was subsequently translated into practice at an American and a Canadian trauma center. The sonographic examination was found to be more accurate and sensitive than CXR (US 96% and 100% versus US 74% and 36%) in specific circumstances. Initial studies have also suggested that detecting the US features of pleural pulmonary ventilation in the left lung field may offer the ability to exclude serious endotracheal tube malpositions such as right mainstem and esophageal intubations. Applied thoracic US is an example of a clinically useful space medicine spin-off that is improving health care on earth.

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.

Ultrasound image quality comparison between an inexpensive handheld emergency department (ED) ultrasound machine and a large mobile ED ultrasound system

Questions have been raised regarding image quality (IQ) provided by portable ultrasound (US) machines.

OBJECTIVES

To determine if a difference exists between images obtained with a common portable US machine and those obtained with a more expensive, larger US machine when comparing typical views used by emergency physicians.

METHODS

The authors performed a cross-sectional, blinded comparison of images from similar sonographic windows obtained on healthy models using a SonoSite 180 Plus and a General Electric (GE) 400 US machine. Both machines were optimized by company representatives. Images obtained included typical abdominal and vascular applications using the abdominal and linear transducers on each machine. All images were printed on identical high-resolution printers and then digitized using a bitmap format at 300 dots-per-inch resolution (RES). Images were then cropped, masked, and placed into random order comparing each view per model by a commercial Web design company (loracs.com). Three credentialed emergency physician sonologists, blinded to machine type, rated each image pair for RES, detail (DET), and total IQ as previously defined in the literature using a ten-point Likert scale; 10 was the best rating for each category. Paired t-test, 95% confidence intervals (95% CIs), and interobserver correlation were calculated.

RESULTS

A total of 49 image pairs were evaluated. Mean GE 400 RES, DET, and IQ scores were 6.8, 6.8, and 6.6, respectively. Corresponding SonoSite means were 6.3, 6.3, and 6.0, respectively. The difference of 0.5 (95% CI = 0.13 to 1.1) for DET was not statistically significant (p = 0.06). The differences of 0.5 (95% CI = 0.1 to 1.1) and 0.6 (95% CI = 0.2 to 1.2) for RES and IQ were statistically significant, with p = 0.01 and 0.01. There was good interobserver agreement (kappa = 0.71; 95% CI = 0.67 to 0.78).

CONCLUSIONS

A statistically significant difference was seen between GE 400 and SonoSite in IQ and RES, but not DET.

The hand-held ultrasound examination for penetrating abdominal trauma

BACKGROUND

An evaluation of hand-held ultrasonography (US) in the assessment of penetrating torso trauma has not yet been reported.

METHODS

A 2.4 kg hand-held ultrasound device was used to examine penetrating trauma victims in an exam designated as the Hand-Held Focused Assessment with Sonography for Trauma (HHFAST). Results were compared with other US examinations including formal FAST (FFAST), computed tomography, diagnostic peritoneal lavage, operative and autopsy findings, and serial examination. Performance considered both the detection of fluid and injuries requiring intervention.

RESULTS

The HHFAST was excellent for detecting free intraperitoneal fluid, which had 100% specificity for peritoneal penetration, but was only moderately sensitive for injuries requiring therapy.

CONCLUSIONS

Hand-held sonography can quickly detect intraperitoneal fluid, which has good test performance in determining the presence of an intra-abdominal injury. Negative FAST examinations after penetrating trauma should be followed up with another diagnostic modality.

A Prospective Evaluation of Ultrasonography for the Diagnosis of Penetrating Torso Injury

BACKGROUND

Ultrasound (US) is commonly used for the diagnosis of hemoperitoneum after blunt abdominal trauma, but the value of US as an aid for identification of operative lesions after penetrating trauma is not well documented. The purpose of this investigation was to determine the accuracy of US for the evaluation of penetrating torso trauma and to assess the impact of this information on patient management.

METHODS

We conducted a prospective cohort observational study of consecutive penetrating torso patients at a Level I trauma center.

RESULTS

During the 6-month trial period, 177 victims of penetrating torso trauma were assessed by our trauma teams. Ninety-two patients had stab wounds, 84 patients had gunshot wounds, and 1 patient had a puncture wound. All 28 patients with positive US examination had an exploratory laparotomy or thoracotomy (one patient had more than one procedure), resulting in 26 therapeutic operations. There were 149 negative US examinations, but in this group, 36 patients underwent laparotomy or thoracotomy, and 28 had therapeutic operations. The overall accuracy of the US examination was therefore 85%, the sensitivity was 48%, and the specificity was 98%. There were only three patients who had their initial management altered by a positive US examination.

CONCLUSION

The US examination lacks sensitivity to be used alone in determining operative intervention after gunshot or stab wounds. Rarely does US information contribute to the management of patients with penetrating abdominal injuries.

Resuscitation of the morbidly obese patient

Obesity is a major health care problem in the United States. The body mass index (BMI) is the standard measure of obesity. A BMI >25 kg/m2 is defined as overweight and obesity as a BMI > 30 kg/m2. Recent surveys indicate that 54% of adults, or roughly 97 million people, are overweight. Given the incidence of obesity in the general population, it is likely that EM physicians will be involved in the emergency care of critically ill or injured obese patients. The objective of this article is to present the clinical problems associated with the resuscitation of the critically ill or injured obese patient and their potential solutions.

Blunt liver injuries in polytrauma: results from a cohort study with the regular use of whole-body helical computed tomography

The estimated prevalence of liver injury in patients with blunt multiple trauma ranges from 1% to 8%. The objective of this study was to investigate the profile of accompanying liver injury in a cohort of polytraumatized patients who had regularly undergone contrast-enhanced, whole-body helical computed tomography (CT). We enrolled consecutive patients admitted between September 1997 and January 2001 to a level I trauma center. Clinical baseline data were compiled as part of a nationwide trauma registry. Morphologic features were evaluated descriptively, whereas prognostic variables were assessed by logistic regression analysis. We identified 218 patients [149 men, mean age 35 +/- 18 years, mean injury severity score (ISS) 35 +/- 10], 55 of whom had sustained blunt liver trauma [25.2%, 95% confidence interval (CI) 19.6-31.5%]. The prevalence of Moore III to V lesions was 10.1%. There were 99 parenchymal contusions, 15 capsular tears, and 2 liver fractures. Surgery was required in 15 patients and was best predicted by the classification of the American Association for the Surgery of Trauma [odds ratio (OR) 3.91, 95% CI 1.59-9.61]. The mortality rate was 0.0035/person/day. Patients requiring surgical repair had fourfold increased relative odds of case fatality (OR 4.50, 95% CI 1.01-19.96). Sevenfold increased relative odds were observed if liver laceration was considered the leading injury (OR 7.17, 95% CI 1.17-43.97). The prevalence of liver lacerations among multiple-trauma patients is likely to be underestimated and must be determined by the independent application of reference standards, such as helical CT. High-grade hepatic injuries and the need for surgical repair are associated with poorer survival prognosis.

Focused Assessment with Sonography for Trauma in weightlessness: a feasibility study

BACKGROUND

The Focused Assessment with Sonography for Trauma (FAST) examines for fluid in gravitationally dependent regions. There is no prior experience with this technique in weightlessness, such as on the International Space Station, where sonography is currently the only diagnostic imaging tool.

STUDY DESIGN

A ground-based (1 g) porcine model for sonography was developed. We examined both the feasibility and the comparative performance of the FAST examination in parabolic flight. Sonographic detection and fluid behavior were evaluated in four animals during alternating weightlessness (0 g) and hypergravity (1.8 g) periods. During flight, boluses of fluid were incrementally introduced into the peritoneal cavity. Standardized sonographic windows were recorded. Postflight, the video recordings were divided into 169 20-second segments for subsequent interpretation by 12 blinded ultrasonography experts. Reviewers first decided whether a video segment was of sufficient diagnostic quality to analyze (determinate). Determinate segments were then analyzed as containing or not containing fluid. A probit regression model compared the probability of a positive fluid diagnosis to actual fluid levels (0 to 500 mL) under both 0-g and 1.8-g conditions.

RESULTS

The in-flight sonographers found real-time scanning and interpretation technically similar to that of terrestrial conditions, as long as restraint was maintained. On blinded review, 80% of the recorded ultrasound segments were considered determinate. The best sensitivity for diagnosis in 0 g was found to be from the subhepatic space, with probability of a positive fluid diagnosis ranging from 9% (no fluid) to 51% (500 mL fluid).

CONCLUSIONS

The FAST examination is technically feasible in weightlessness, and merits operational consideration for clinical contingencies in space.

The hand-held FAST: experience with hand-held trauma sonography in a level-I urban trauma center

AIMS

To describe the effectiveness of a portable hand-held ultrasound machine when used by clinicians in the early evaluation and resuscitation of trauma victims.

METHODS

The study was a prospective evaluation in a level-I urban trauma center. The focussed assessment with sonography for trauma is a specifically defined examination for free fluid known as the focused assessment with sonography for trauma (FAST) exam. Seventy-one patients had a hand-held FAST (HHFAST) examination performed with a Sonosite 180, 2.4 kg ultrasound machine. Sixty-seven examinations were immediately repeated with a Toshiba SSH 140A portable floor-based machine. This repeat scan (formal FAST or FFAST) was used as a comparison standard between the devices for study purposes. Four patients had a HHFAST only, all with positive result, two being taken for immediate laparotomy, and two having a follow-up computed tomographic (CT) scan. Patient follow-up from other imaging studies, operative intervention, and clinical outcomes were also compared to the performance of each device.

RESULTS

There were 58 victims of blunt, and 13 of penetrating abdominal trauma. One examination was indeterminate using both machines. The apparent HHFAST performance yielded; sensitivity, specificity, positive predictive value, negative predictable value, and accuracy (S, S, PPV, NPV, A) of 83, 100, 100, 98, 98%. Upon review, a CT scan finding and benign clinical course found the HHFAST diagnosis to be correct rather than the FFAST in one case. Considering the ultimate clinical course of the patients, yielded a (S, S, PPV, NPV, A) of 78, 100, 100, 97, and 97% for the HHFAST and 75, 98, 86, 97, and 96% for the FFAST. Statistically, there was no significant difference in the actual performance of the HHFAST compared to the FFAST in this clinical setting.

DISCUSSION

Hand-held portable sonography can simplify early and accurate performance of FAST exams in victims of abdominal trauma.

Intraperitoneal blood missed on a FAST examination using portable ultrasound

Bedside ultrasonography is rapidly gaining popularity in the evaluation of emergency patients. Several manufacturers have developed hand-held ultrasound machines that make the technology easy to transport and available in settings where such diagnostic tests were previously unobtainable. The miniaturization of equipment often means compromises and no studies exist comparing the high quality imaging capabilities of larger conventional ultrasound units to hand-held machines on actual patients. We present 3 cases in which intra-abdominal fluid stripes, important markers of intraperitoneal bleeding, were not visible with a popular hand-held unit, but were identified with a larger mobile ultrasound machine. These findings should caution emergency physicians to be aware of this limitation along with the many advantages of these new and popular hand-held ultrasound units.

Role of ultrasonography in penetrating abdominal trauma: a prospective clinical study

BACKGROUND

Focused Assessment with Sonography for Trauma (FAST) is rapidly establishing its place in the evaluation of blunt abdominal trauma. However, no prospective study specifically evaluates its role in penetrating abdominal trauma.

METHODS

Data were collected prospectively in 75 consecutive stable patients with penetrating trauma to the abdomen, flank, or back, from December 1998 to June 1999. Those with an obvious need for emergent laparotomy were excluded. FAST was performed as the initial diagnostic study on all patients. Wound location, type of weapon, and findings of diagnostic peritoneal lavage, triple-contrast computed tomographic scan, or laparotomy were recorded. The presence of peritoneal blood was noted. Data were analyzed using the chi(2) test.

RESULTS

Of the 75 patients, there were 32 stab and 43 gunshot wounds. There were 66 male patients and 9 female patients; the mean age was 30 years; 41 had proven abdominal injury and 34 had no injury; and 21 patients had a positive FAST. Nineteen had peritoneal blood and injuries requiring repair at the time of laparotomy. There were two false-positive studies. Fifty-four patients had a negative FAST. In 32 patients, this was a true-negative study. Thirteen patients had a false-negative FAST and had peritoneal blood and significant injury on further evaluation. Nine patients had a negative FAST and no peritoneal blood but still had abdominal injuries requiring operative repair, including liver (four), small bowel (four), diaphragm (three), colon (three), and stomach (one). The overall sensitivity of FAST was 46% and the specificity was 94%. The positive predictive value was 90%, and the negative predictive value was 60%.

CONCLUSION

FAST can be a useful initial diagnostic study after penetrating abdominal trauma. A positive FAST is a strong predictor of injury, and patients should proceed directly to laparotomy. If negative, additional diagnostic studies should be performed to rule out occult injury.

Management of traumatically injured patients in the emergency department observation unit

An EDOU may be an ideal setting for the short-term monitoring and treatment of certain acutely injured patients. The patients choosen for observation, and the diagnostic studies used, will be specific to a particular institution's availability and expertise. Pathways should be developed in conjunction with all services caring for these patients.

2,576 ultrasounds for blunt abdominal trauma

BACKGROUND

Determination of intra-abdominal injury following blunt abdominal trauma (BAT) continues to be a diagnostic challenge. Ultrasound (US) has been described as a potentially useful diagnostic tool in this setting and is being used with increasing frequency in trauma centers. We determined the diagnostic capability of US in the evaluation of BAT.

METHODS

A retrospective analysis of our trauma US database was performed over a 30-month period. Computed tomographic scan, diagnostic peritoneal lavage, or exploratory laparotomy confirmed the presence of intra-abdominal injury.

RESULTS

During the study period, 8,197 patients were evaluated at the Ryder Trauma Center. Of this group, 2,576 (31%) had US in the evaluation of BAT. Three hundred eleven (12%) US exams were considered positive. Forty-three patients (1.7%) had a false-negative US; of this group, 10 (33%) required exploratory laparotomy. US had a sensitivity of 86%, a specificity of 98%, and an accuracy of 97% for detection of intra-abdominal injuries. Positive predictive value was 87% and negative predictive value was 98%.

CONCLUSION

Emergency US is highly reliable and may replace computed tomographic scan and diagnostic peritoneal lavage as the initial diagnostic modality in the evaluation of most patients with BAT.

Sonographic assessment of traumatic injury. Future developments

In all its forms and applications, sonography plays a significant role in the management of injured patients, from the emergency department to beyond hospital discharge. The use of new and existing sonographic technology will increase because sonographic imaging and measurements are generally less invasive; are inexpensive; use no ionizing radiation; and are portable, repeatable, and, in many instances, as accurate as the so-called "contemporary gold standards." The training and credentialing of physicians in sonography is in evolution and will be an increasingly important issue with more widespread use and broader applications. The future of sonography in trauma care in the next millennium is bright, and surgeons and surgical residents are encouraged to gain proficiency and learn about this new surgical frontier as it evolves.

Prospective evidence of the superiority of a sonography-based algorithm in the assessment of blunt abdominal injury

BACKGROUND

Although the routine use of FAST (focused assessment with sonography for trauma) in the evaluation of trauma victims is increasing, to our knowledge, a prospective comparison of contemporary adult trauma victims managed with and without FAST has not been reported in North America.

METHODS

Adult victims of blunt trauma for whom there was a suspicion of abdominal injury were managed with one of two diagnostic algorithms, FAST or no-FAST. The two algorithms were compared for diagnostic accuracy, cost, time, and delayed diagnoses.

RESULTS

Among 706 patients (mean Injury Severity Score, 23), 460 were managed with FAST and 246 with no-FAST. The two groups were similar with respect to age, Injury Severity Score, prehospital time, and mortality (p = not significant). There were 3 of 460 (0.7%) delayed diagnoses in the FAST group and 4 of 246 (1.6%) in the no-FAST group (p = not significant). The diagnostic accuracy for the FAST and no-FAST algorithms was 99% and 98%, respectfully. The FAST and no-FAST algorithms led to similar rates of laparotomy, 13% and 14%, respectfully, but nonoperative management was more common in the no-FAST group (p < 0.01). The mean diagnostic cost for the FAST algorithm was $156, compared with $540 with the no-FAST algorithm (p < 0.0001) and the mean time required for diagnostic work-up was 53 minutes with the FAST algorithm, compared with 151 minutes with the no-FAST algorithm (p < 0.0001).

CONCLUSION

This study has provided prospective evidence that a FAST-based algorithm for blunt abdominal injury was more rapid, less expensive, and as accurate as an algorithm that used computed tomography or diagnostic peritoneal lavage only. Trauma centers are encouraged to incorporate a FAST-based algorithm into their initial management of blunt trauma victims.

Focused abdominal sonogram for trauma: the learning curve of nonradiologist clinicians in detecting hemoperitoneum

BACKGROUND

The focused abdominal sonogram for trauma (FAST) has been used by surgeons and emergency physicians (CLIN) to screen reliably for hemoperitoneum after trauma. Despite recommendations for "appropriate training," ranging from 50 to 400 proctored examinations, there are no supporting data.

METHODS

We prospectively examined the initial FAST experience of CLIN in detecting hemoperitoneum by using diagnostic peritoneal lavage, computed tomography, and clinical findings as the diagnostic "gold standard."

RESULTS

241 patients had FAST performed by 12 CLIN (average, 20/CLIN; range, 2-43); 51 patients (21.2%) had hemoperitoneum and 17 patients (7.1%) required laparotomy. Initial experience with FAST by CLIN produced 35 true positives, 180 true negatives, 16 false negatives, and 3 false positives; sensitivity, 68%; specificity, 98%. Initial error rate was 17%, which fell to 5% after 10 examinations (chi2; p < 0.05).

CONCLUSION

Previous recommendations for the number of proctored examinations for individual nonradiologist clinician sonographers to develop competence are excessive.