Prospective analysis of a rapid trauma ultrasound examination performed by emergency physicians

Ultrasonography by emergency physicians in patients with suspected ureteral colic

We performed a prospective study of patients with suspected ureteral colic to evaluate the test characteristics of bedside renal ultrasonography (US) performed by emergency physicians (EPs) for detecting hydronephrosis, and to evaluate how US can be used to predict the likelihood of nephrolithiasis. Thirteen EPs performed US, recorded the presence of hydronephrosis, and made an assessment of the likelihood of nephrolithiasis. All patients underwent i.v. pyelography (IVP) or unenhanced helical computed tomography (CT). There were 126 patients in the study: 84 underwent IVP; 42 underwent helical CT. Test characteristics of bedside US for detecting hydronephrosis were: sensitivity 72%, specificity 73%, positive predictive value (PPV) 85%, negative predictive value (NPV) 54%, accuracy 72%. The PPV and NPV for the ability of the EP to predict nephrolithiasis after performing US were 86% and 75%, respectively. We conclude that bedside US performed by EPs may be used to detect hydronephrosis and help predict the presence of nephrolithiasis.

Diagnosis of spontaneous splenic rupture with emergency ultrasonography

Rapid evaluation of the hypotensive patient in the emergency department is essential. The availability of ultrasonography in the ED, performed by emergency physicians and surgeons, has made it easier to evaluate the hypotensive trauma patient. We describe a 44-year-old man transferred to our institution from a community hospital for evaluation of syncope and hypotension with no obvious cause. On arrival the patient began to complain of slight lower abdominal pain. The patient's physical examination revealed minimal abdominal tenderness. A rapid ultrasound examination performed at bedside revealed the presence of intraperitoneal fluid. Examination of the spleen suggested likely rupture. The patient was promptly taken to surgery for splenectomy and discharged home in 4 days.

Early detection of hemoperitoneum by ultrasound examination of the right upper quadrant: a multicenter study

BACKGROUND

The focused assessment for the sonographic examination of the trauma patient (FAST) is a rapid diagnostic test that sequentially surveys for hemopericardium and then the right upper quadrant (RUQ), left upper quadrant (LUQ), and pelvis for hemoperitoneum in patients with potential truncal injuries. The sequence of the abdominal part of the examination, however, has yet to be validated. The objectives of this multicenter study were as follows: (1) to determine where hemoperitoneum is most frequently identified on positive FAST examinations; and (2) to determine if a relationship exists between that areas and the organs injured.

METHODS

Ultrasound registries from four Level I trauma centers identified patients who had true-positive FAST examinations. Demographic data, areas positive on the FAST, and organs injured were recorded; injuries were classified as multiple, single solid organ (liver or spleen), isolated hollow viscus, or retroperitoneal. Relationships between positive locations on the FAST examinations and the associations of organs injured to areas positive were assessed using McNamara's chi2 test; a p value < 0.05 was considered statistically significant.

RESULTS

The RUQ was the most common site where hemoperitoneum was detected, and this was statistically significant compared with either the LUQ or the pelvis. Also, statistically significant correlations (p < 0.001) were observed between positive RUQ areas on the FAST and multiple injuries, single solid organ (liver or spleen) injury, and retroperitoneal injuries.

CONCLUSION

Blood is most often found on the FAST in the RUQ area in patients with multiple intraperitoneal injuries or isolated injury to the liver, spleen, or retroperitoneum, but not when there is injury to a hollow viscus.

Transvaginal ultrasonography by emergency physicians decreases patient time in the emergency department

OBJECTIVES

An important argument for emergency physician use of ultrasonography is that it results in more rapid patient disposition, but there are few articles to support this position. This study sought to demonstrate a significant decrease in the time spent in the ED when emergency physicians performed transvaginal ultrasonography (TVUS), as compared with when TVUS was performed by consultants, in the evaluation of first-trimester pelvic pain or vaginal bleeding.

METHODS

A retrospective analysis was conducted of the time spent in the ED (time placed in gynecologic examination room to time released from ED) by patients with first-trimester pelvic pain or vaginal bleeding necessitating further evaluation with TVUS. TVUS was performed in the ED by obstetrics/gynecology (ob/gyn) residents who were consulted to the ED from January 11, 1996, to March 31, 1996, and by emergency physicians from April 17, 1996, to July 7, 1996.

RESULTS

Emergency physicians evaluated 46 patients by TVUS, with a mean time of 164.70 minutes (SEM +/- 13.29). Ob/gyn consultants evaluated 38 patients by TVUS, with a mean time of 234.79 minutes (SEM +/- 12.74). This was a significant difference at the level of p < 0.0003 (Student's t-test). There were no known missed ectopic pregnancies as ascertained by 100% patient follow-up. There was no significant difference between the groups in the percentage of ectopic pregnancies (Fisher's exact test). The number of patients in the emergency physician group requiring subsequent consultation was reduced by 85%.

CONCLUSIONS

This study demonstrates a more rapid ED transit time when TVUS was performed at the bedside by emergency physicians as compared with when pelvic ultrasonography required consultation. Additionally, fewer calls to consultants were required.

The indeterminate abdominal sonogram in multisystem blunt trauma

BACKGROUND

North American trauma centers are beginning to note the limitations of emergent torso sonography. The purpose of this prospective study was to evaluate the frequency, causes, associations, and sequelae of indeterminate (IND) sonograms in blunt trauma.

METHODS

Among adult blunt trauma patients assessed with screening torso sonography, clinician sonographers recorded the abdominal sonogram as positive, negative, or IND for free fluid. Patients with IND sonograms were further investigated with repeat sonography, computed tomography, or diagnostic peritoneal lavage.

RESULTS

Among 417 patients with blunt trauma (mean Injury Severity Score = 21) managed with sonography, there were 28 (6.7%) IND and 389 (93.3%) non-IND sonograms. Sonograms were IND because of patient factors in 71% (20 of 28) and because of operator factors in 29% (8 of 28). None of the 28 patients were managed with repeat sonography alone. All 4 diagnostic peritoneal lavage examinations gave negative results, whereas 8 of 23 computed tomographic scans were abnormal (6 of 8 patients underwent laparotomy). The mean time required for diagnostic workup was 117 minutes in the IND group and 48 minutes in the non-IND group (p < 0.001 in both cases).

CONCLUSION

This prospective study has demonstrated that IND sonograms are not common at our center (6.7%), are usually attributable to patient factors, and are associated with greater diagnostic time. Patients with IND sonograms require further investigation because they often have injuries requiring laparotomy.

A comparison of sonographic examinations for trauma performed by surgeons and radiologists

BACKGROUND

It has been demonstrated that surgeons and surgery residents, trained in the focused abdominal sonographic examination, are able to accurately and reliably evaluate trauma patients. Despite this, radiologists have objected to surgeon-performed sonography for several reasons. We set out to compare the accuracy of sonographic examinations performed by surgery residents and radiologists.

METHODS

A retrospective review of medical records of all trauma patients who received focused ultrasound examinations from January 1, 1995, through June 30, 1996, at one of two American College of Surgeons-verified Level I trauma centers in the same city was undertaken. Ultrasound examinations were performed by surgery residents at trauma center A (TCA) and by radiologists or radiology residents at trauma center B (TCB). Findings for each patient were compared with the results of computed tomography, diagnostic peritoneal lavage, operative exploration, or observation. Sensitivity, specificity, accuracy, positive predictive value, and negative predictive value were calculated for each group of patients. Comparison of patient charges for the trauma ultrasound examinations at each of the trauma centers was also made.

RESULTS

Patient populations at the two centers were similar except that the mean Injury Severity Score at TCB was higher than at TCA (11.74 vs. 9.6). Sensitivity, specificity, accuracy, or negative predictive value were not significantly different between the two cohorts. A significantly lower positive predictive value for examinations performed by surgery residents was noted and attributed to a lower threshold of the surgery residents to confirm their findings by computed tomography. Billing data revealed that the average charge for trauma sonography by radiologists (TCB) was $406.30. At TCA, trauma sonography did not generate a specific charge; however, a $20.00 sum was added to the trauma activation fee to cover ultrasound machine maintenance and supplies.

CONCLUSION

Focused ultrasound examination in the trauma suite can be as safely and accurately performed by surgery residents as by radiologists and radiology residents and should be a routine part of the initial trauma evaluation process.

Swine and dynamic ultrasound models for trauma ultrasound testing of surgical residents

BACKGROUND

Trauma ultrasound workshops have been recommended for training surgical residents. We assessed the teaching effectiveness of the workshop, comparing swine and dynamic patient ultrasound models.

MATERIALS AND METHODS

MCQ exams on ultrasound physics and practical skills tests with and without pericardial or peritoneal fluid using four swines and eight dynamic patient ultrasound videos were used to compare pre- and postworkshop performance in 18 surgical residents (Group I) and a matched control group of 18 (Group II). Paired t tests and unpaired t tests for paired and unpaired data, respectively, were used for analysis with a P < 0.05 being considered statistically significant.

RESULTS

Mean scores (% correct response) +/- SD were as follows (*P < 0.05 vs Group I). [table: see text] For the swine model, the best scores were with pericardial fluid (25.0% pre vs 69.4% post in Group I) and the worst scores were with RUQ fluid (5.6% pre vs 22.2% post in Group I). Postworkshop dynamic video scores were always higher than the swine model scores in Group I (100% correct video scores for pericardial fluid).

CONCLUSIONS

This study confirms the trauma ultrasound workshop teaching effectiveness. For testing, the swine model (especially RUQ) was more difficult. In postcourse evaluation, the dynamic human video was considered more relevant, realistic, and less costly for repeated testing of the residents.

Penetrating thoracoabdominal trauma

Penetrating injuries to the thoracoabdominal region represent a complex and diverse population of injuries. The clinician managing such cases must be able to consider all potential injuries, rapidly recognize life-threatening sequelae, and precisely diagnose and quickly manage these patients. The diverse nature of some of the potential presentations of patients with penetrating thoracoabdominal trauma is discussed. The most recent advances and controversies involving the evaluation and management of patients with penetrating thoracoabdominal trauma are also discussed.

Echocardiography in thoracic trauma

The availability of bedside ultrasonography can dramatically impact the care of patients with cardiac or aortic injuries. A focused, limited echocardiographic examination in the initial evaluation of victims with thoracic injuries can provide vital information the clinician needs to expedite the management of these patients. This article reviews the current use of transthoracic and transesophageal echocardiography in patients with thoracic trauma.

Rapid detection of traumatic effusion using surgeon-performed ultrasonography

BACKGROUND

In the injured patient, rapid assessment of the thorax can yield critical information for patient management and triage.

OBJECTIVES

The objectives of this prospective study were (1) to determine if experienced surgeon sonographers could successfully use a focused thoracic ultrasonographic examination to detect traumatic effusion, and (2) to compare the accuracy and efficiency of ultrasonography with supine portable chest radiography.

METHODS

Surgeon-sonographers performed thoracic ultrasonographic examinations on patients with blunt and penetrating torso injuries during the Advanced Trauma Life Support secondary survey. All patients also underwent portable chest radiography. Performance times for ultrasonography and chest radiography were recorded. Comparisons were made of the performance times and accuracy of both tests in detecting traumatic effusion.

RESULTS

In 360 patients, there were 40 effusions, 39 of which were detected by ultrasonography and 37 of which were detected by chest radiography. The 97.5% sensitivity and 99.7% specificity observed for thoracic ultrasonography were similar to the 92.5% sensitivity and 99.7% specificity for portable chest radiography. Performance time for ultrasonography was significantly faster than that for chest radiography (1.30 +/- 0.08 vs. 14.18 +/- 0.91 minutes, p < 0.0001).

CONCLUSION

Surgeons can accurately perform and interpret a focused thoracic ultrasonographic examination to detect traumatic effusion. Surgeon-performed thoracic ultrasonography is as accurate but is significantly faster than supine portable chest radiography for the detection of traumatic effusion.

The emerging role of bedside ultrasonography in trauma care

Ultrasonography has emerged as a primary imaging modality in the evaluation of the trauma victim. Both emergency physicians and surgeons have been proven capable of performing this rapid, noninvasive evaluation of the chest and abdomen. This article describes the trauma ultrasound examination and illustrates how bedside ultrasonography can be incorporated into routine trauma care.

Evaluation of an instructional model for emergency ultrasonography

OBJECTIVE

To evaluate a 4-hour ultrasonography course in the setting of an emergency medicine (EM) training program.

METHODS

EM residents and faculty at a large urban center were provided a 4-hour emergency ultrasonography course. Then, during an 18-month period, a nonconsecutive sample of ultrasonographic examinations were videotaped and later reviewed. The interpretations of the emergency, physician examinations were compared with the following reference standards: 1) an official ultrasound performed and interpreted by the departments of radiology or cardiology; 2) an operative report; 3) A CT scan or i.v. pyelogram (IVP); or 4) a cardiologist's or a radiologist's interpretation of the videotaped examinations.

RESULTS

Of 258 examinations reviewed, 28 (11%) of these were excluded because the cardiologist or radiologist reviewing the videotape determined them to be "technically limited" studies. Of the remaining 230 examinations, there were: 127 gallbladder studies [disease prevalence = 0.58; sensitivity = 0.89; specificity = 0.80; kappa (kappa) = 0.69; 95% CI: 56-82%]; 39 echocardiograms to rule out pericardial effusions [disease prevalence = 0.15; sensitivity = 0.83; specificity = 0.97 kappa = 0.80; 95% CI: 54-100%]; 25 abdominal ultrasounds to rule out free peritoneal fluid [disease prevalence = 0.32; sensitivity = 0.88; specificity = 0.94; kappa = 0.81; 95% CI: 26-95%]; 16 renal ultrasounds to rule out hydronephrosis [disease prevalence = 0.25; sensitivity = 1.0; specificity = 0.92; kappa = 0.84; 95% CI: 56-100%]; 12 pelvic ultrasounds to rule in an intrauterine pregnancy [disease prevalence = 0.67; sensitivity = 1.0; specificity = 0.75; kappa = 0.80; 95% CI: 43-100%]; and 11 abdominal ultrasounds to rule out abdominal aortic aneurysms [disease prevalence = 0.09; sensitivity = 1.0; 95% CI: 2.5-91%; specificity = 1.0; 95% CI: 68-100%].

CONCLUSIONS

This 4-hour ultrasonography course has potential to serve as a foundation for an instructional model for ultrasonography training in the setting of an EM residency program.

The value of current developments in radiology to the accident and emergency department--a pictorial review

Images

Credentialing issues in emergency ultrasonography

The use of ultrasonography, traditionally performed by radiologists, is becoming increasingly widespread in emergency medicine. Consequently, much debate has evolved over whether emergency medicine physicians are qualified to provide this service, and the criteria by which training and credentialing can be achieved. This article discusses training and credentialing guidelines, paths to becoming credentialed in emergency sonography, and quality assurance issues. Also, strategies are proposed for emergency departments seeking to perform emergency sonography.

Abdominal injuries without hemoperitoneum: a potential limitation of focused abdominal sonography for trauma (FAST)

BACKGROUND

Focused abdominal sonography for trauma (FAST) relies on hemoperitoneum to identify patients with injury. Blunt trauma victims (BTVs) with abdominal injury, but without hemoperitoneum, on admission are at risk for missed injury.

METHODS

Clinical, radiologic, and FAST data were collected prospectively on BTVs over a 12-month period. All patients with FAST-negative for hemoperitoneum were further analyzed. Examination findings and associated injuries were evaluated for association with abdominal lesions.

RESULTS

Of 772 BTVs undergoing FAST, 52 (7%) had abdominal injury. Fifteen of 52 (29%) had no hemoperitoneum by admission computed tomographic scan, and all had FAST interpreted as negative. Four patients with splenic injury underwent laparotomy. Six other patients with splenic injury and five patients with hepatic injury were managed nonoperatively. Clinical risk factors significantly associated with abdominal injury in BTVs without hemoperitoneum include: abrasion, contusion, pain, or tenderness in the lower chest or upper abdomen; pulmonary contusion; lower rib fractures; hemo- or pneumothorax; hematuria; pelvic fracture; and thoracolumbar spine fracture.

CONCLUSIONS

Up to 29% of abdominal injuries may be missed if BTVs are evaluated with admission FAST as the sole diagnostic tool. Consideration of examination findings and associated injuries should reduce the risk of missed abdominal injury in BTVs with negative FAST results.

Prospective study investigating routine usage of ultrasonography as the initial diagnostic modality for the evaluation of children sustaining blunt abdominal trauma

In this prospective study, 217 children sustaining blunt abdominal trauma were initially evaluated with ultrasonography (US) and those with any abnormal ultrasonographic findings were further evaluated with computed tomography. Results of ultrasonographic examination were normal in 157 children and showed abnormalities such as free intraperitoneal fluid (FIF), intra-abdominal organ injury, and intrapleural fluid in 60 children. Computed tomographic examination of the 42 children with organ injury, the seven children with minimal FIF of no definite source, and the three children with intrapleural fluid revealed findings consistent with ultrasonographic findings. Computed tomographic examination of the eight children with more than minimal FIF of no definite source detected by US showed the source as liver injury in one and spleen injuries in two patients. The source of FIF could not be identified with computed tomography in five patients. After clinic follow-up examination, one of these five patients was operated on for abdominal tenderness, fever, and air-fluid levels detected on plain abdominal radiographs, and duodenal perforation was encountered. Clinical courses of the patients with normal ultrasonographic findings were uneventful. We conclude that US, aside from being a screening tool, is alone sufficient in the evaluation of the majority of the children sustaining blunt abdominal trauma. Although this is a preliminary study with further work needed to be done, we propose that further evaluation with computed tomography should be performed on those children in whom more than minimal FIF of no definite source is detected with US.

Trauma ultrasound examination versus chest radiography in the detection of hemothorax

STUDY OBJECTIVE

To compare the sensitivity, specificity, and accuracy of ultrasonography with those of the initial plain chest radiograph for detection of hemothorax in trauma patients.

METHODS

Data from a prior prospective study of trauma ultrasonography at a Level I trauma center were retrospectively analyzed. The medical records of a convenience sample of adult patients who presented with major blunt or penetrating torso trauma during a 17-month period were reviewed. Emergency physicians performed a trauma ultrasound examination, which included evaluation for pleural fluid. Ultrasound interpretations were recorded before other diagnostic tests were obtained and were not used in patient management decisions. Records of the study patients were reviewed for confirmation of the presence or absence of hemothorax by other diagnostic and therapeutic interventions. The chest radiograph and computed tomography (CT) scan interpretations were performed by attending radiologists who were not blinded to patient outcome.

RESULTS

Five of the 245 patients enrolled in the study were excluded because tube thoracostomy was performed before the ultrasound examination was done. Altogether, 26 of the 240 study patients had hemothorax, as confirmed by tube thoracostomy or CT. Both ultrasound examination and the initial chest radiograph resulted in 0 false-positive, 1 false-negative, 25 true-positive, and 214 true-negative findings. Overall, both modailties were 96.2% sensitive, 100% specific, and 99.6% accurate.

CONCLUSION

Ultrasonography is comparable to the initial chest radiograph for accuracy in detection of hemothorax and may expedite the diagnosis and treatment of this condition for patients with major trauma.

Detection of traumatic complications of cardiopulmonary resuscitation by ultrasound

STUDY OBJECTIVE

We conducted a pilot study to assess the feasibility of ultrasonography in the detection of traumatic complications of CPR.

METHODS

A prospective case series was undertaken with a convenience sample of 21 emergency department patients who sustained nontraumatic cardiopulmonary arrest. A 5- to 7-minute ultrasound examination was performed during resuscitation. The presence or absence of free fluid was noted in the left and right upper quadrants, coronal views of the kidneys, the pelvis, and the pericardium; autopsies to determine the source of fluid were not performed. Cardiac activity and the concurrent electrical rhythm were also noted. All ultrasonographers had previously been trained in the use of this technique for the evaluation of trauma patients. Examinations were stored on videotape for further review.

RESULTS

Seven of 20 patients (29%) had findings on ultrasound that could have resulted from CPR-related trauma. In one additional case, findings of free fluid were probably the result of preexisting illness (ascites). Pericardial effusion was found in three patients, perihepatic fluid in four, pleural fluid in one, perirenal fluid in four, perisplenic fluid in two, and pelvic fluid in three; several patients had multiple findings. Cardiac motion with pulseless electrical activity was noted in seven patients. Five patients had return of spontaneous circulation and survived to hospitalization, and one survived to discharge.

CONCLUSION

Traumatic complications of CPR are well known but typically difficult to assess. Ultrasonography may identify injuries, help guide procedures, and serve as a means to assess pharmacologic effects on cardiac performance during CPR. It is a readily available, noninvasive means to assess these critically ill patients.

Ultrasound in the evaluation and management of blunt abdominal trauma

Failure to detect intraabdominal injury in the patient with blunt trauma may result in significant morbidity and mortality. The diagnosis of abdominal injury remains a clinical challenge. Presented here is a review of recent literature comparing ultrasound with diagnostic peritoneal lavage and computed tomography in the evaluation of blunt abdominal trauma.

Use of ultrasound to determine need for laparotomy in trauma patients

STUDY OBJECTIVE

To determine whether abdominal ultrasound can be used routinely as the primary screening test to identify the need for laparotomy in trauma patients.

METHODS

Ultrasound was used at a Level II trauma center as a primary screening test for evaluation of intraabdominal injury. We reviewed the charts of all patients from trauma codes presenting between January 1, 1991, and December 31, 1993, to determine the results of abdominal ultrasound evaluation and to learn whether laparotomy was required.

RESULTS

A total of 2,013 trauma patients presented during the study interval. Ultrasound was performed in 1,631 patients as the primary screening test for abdominal injury (mean time after arrival, 22.9 minutes), abdominal computed tomography (CT) was performed as the primary screen on 8 (mean time, 68.6 minutes), and 93 patients underwent both ultrasound and CT of the abdomen. Of 86 patients requiring laparotomy who were screened by ultrasound, 80 had positive diagnostic findings, for a sensitivity of 93.0%. Of the 1,545 ultrasound-screened patients who did not require laparotomy, 1,390 had negative findings, for a specificity of 90.0%. None of the patients with negative ultrasound results died or sustained identifiable mortality as a consequence of their negative scans.

CONCLUSION

Ultrasound is a sensitive and specific test with which to evaluate trauma patients for abdominal injury requiring surgery. Routine abdominal ultrasound can be performed at the bedside in the emergency department as a timely, noninvasive diagnostic test. This use of a screening abdominal ultrasound examination can improve clinical decision-making for the use of emergency laparotomy. Ultrasound may be a better alternative to CT or diagnostic peritoneal lavage for the initial screening evaluation of abdominal trauma.

Hypotension after blunt abdominal trauma: the role of emergent abdominal sonography in surgical triage

OBJECTIVE

Trauma victims with hypotension require a rapid and reliable localization of bleeding and expedient surgical triage. Our hypothesis is that emergent abdominal sonography (EAS) is a rapid and accurate test of the need for urgent laparotomy in blunt trauma victims with hypotension.

METHODS

Among 400 blunt trauma victims entered in a prospective blind study of EAS, a subgroup of 69 (17%) patients had a systolic blood pressure < or = 90 mm Hg during their initial assessment. Although the EAS results [(+) = fluid, (-) = no fluid] were not used in clinical decision making, the potential contribution of EAS to patient care was examined.

RESULTS

The mean Injury Severity Score was 32. Twenty-two (32%) patients were EAS (+), of which 19 required an acute laparotomy. No laparotomies were performed in the 47 EAS (-) patients. The EASs required 19 +/- 5 seconds in the EAS (+) group and 154 +/- 13 seconds in the EAS (-) group. Twenty of the 22 positive EASs had free fluid in Morison's pouch. All 13 patients with an ultrasound score > or = 3 had a laparotomy. The primary etiology of hypotension was blood loss in 42 patients, hemoperitoneum in 18, and retroperitoneal hemorrhage in 12.

CONCLUSION

EAS is a rapid and accurate indicator of the need for urgent laparotomy in the hypotensive blunt trauma victim. Further, a negative EAS can hasten the search for other causes of hypotension. Diagnostic peritoneal lavage may become obsolete in centers with EAS capabilities.

Emergency physician use of ultrasonography in blunt abdominal trauma

OBJECTIVE

To evaluate the diagnostic utility of abdominal diagnostic ultrasonography (DUS) performed by emergency physicians for intraperitoneal fluid caused by blunt abdominal trauma (BAT).

METHODS

The design was a prospective, blind, observational study. During a 15-month period, a convenience sample of patients presenting to the ED with BAT necessitating CT scan of the abdomen, diagnostic peritoneal lavage (DPL), or laparotomy was studied. Scans were performed by an emergency medicine (EM) attending, or a resident supervised by an attending, using a real-time sector ultrasound scanner with a 3.5-MHz probe. Training in DUS included a 1-hour didactic session and 1 hour of practice on human volunteers. Free intraperitoneal fluid was defined as an anechoic stripe in the hepatorenal, bladder-rectal, or splenorenal space, and constituted a positive DUS study. Free intraperitoneal fluid detected on abdominal CT scan, DPL, and/or laparotomy was the criterion standard.

RESULTS

Of 110 patients scanned, 13 were excluded secondary to technical difficulty or lack of diagnostic follow-up modalities. Of the remaining 97 patients, there were 24 females and 73 males, ranging from ages 2 to 78 years. DUS detected intraperitoneal fluid in 21 subjects, including 3 false positives. There were 6 false-negative DUS examinations. DUS had a sensitivity of 75% (95% CI 53-90%), a specificity 96% of (95% CI 89-99%), and an accuracy of 91% (95% CI 83-96%). No false-positive or false-negative DUS study occurred after the first 67 cases. The mean interval for a DUS scan was 4.9 +/- 2.9 minutes, ranging from 0.5 to 16 minutes, and the mean intervals were not different between the positive and the negative studies. The accuracies of DUS were similar in the pediatric patients, 97% (95% CI 83-100%), and in the adults, 88% (95% CI 78-95%). The hepatorenal view provided the highest sensitivity as well as the least number of uninterpretable scans of the 3 DUS views.

CONCLUSION

Emergency physicians with minimal training can use DUS with fair sensitivity and good specificity and accuracy to detect free intraperitoneal fluid in both pediatric and adult BAT victims. The hepatorenal view provides the highest sensitivity for intraperitoneal fluid, although the 3-view series (with hepatorenal, bladder-rectal, and splenorenal spaces) can typically be performed within 5 minutes and may increase the specificity and accuracy.

Ultrasound in the diagnosis of injury

Ultrasound is one of several modalities useful in the work-up of an injured patient. It is a bedside technique which is quick, economical and highly reliable in filtering out the patients who are in urgent need of laparotomy. For the moment, this is the prime and only function of this modality. The US examination can and should be repeated with a very low threshold. Apart from the complication rate, which is zero for US, it shares many virtues with DPL. Ultrasonography in a badly injured victim is a challenging investigation which should be done by an expert. In most situations, this will be a radiologist whose presence in the emergency room could further be used for expert film reading and development as well as the unhampered implementation of a rational follow-up imaging strategy. Follow-up modalities, however impressive, should not be compared with first-line investigations. In expert hands, accuracy figures between DPL and US do not differ decisively but one must bear in mind that DPL spans only one compartment while US gives information about much more vital areas. DPL is complementary to US; it is of paramount importance to understand that DPL spoils the US examination (and CT as well) but is not hindered by repeated US. DPL can and should be used to investigate the nature of free intra-peritoneal fluid when the amount does not warrant laparotomy. Neither US nor DPl are substitutes for sound clinical judgement.

Emergent abdominal sonography as a screening test in a new diagnostic algorithm for blunt trauma

Although there is an interest in emergent abdominal sonography (EAS), the clinical utilization of EAS in North America is minimal. The purpose of this study was to develop a new diagnostic algorithm for blunt abdominal injury based on a prospective blinded comparison of EAS, diagnostic peritoneal lavage (DPL), and computed tomography (CT). EAS (+ = fluid, - = no fluid) was performed before the DPL or CT, in 400 patients with a mean Injury Severity Score of 26; 293 had a CT and 107 had a DPL. The EASs required 2.6 +/- 1.2 minutes with 82% < or = 3 minutes. The accuracy of EAS for free fluid was 94% with a positive and negative predictive value of 82 and 96%, respectively. Only 1 of 338 patients with EAS- had an acute therapeutic laparotomy. Three patients with EAS- had a delayed laparotomy based on evolving clinical findings. The radiologists interpretation of the EAS video disagreed with the clinician sonographer in only 3% of cases. Based on these results, a diagnostic algorithm was developed using EAS as a screening test with selective use of DPL and CT. Emergent abdominal sonography performed by clinician sonographers is a rapid and accurate test for peritoneal fluid in blunt trauma victims, and the need for laparotomy in patients with a negative EAS is rare. Our study supports the routine use of EAS as a screening test in a diagnostic algorithm for the evaluation of blunt abdominal trauma.

A prospective evaluation of abdominal ultrasound in blunt trauma: is it useful?

OBJECTIVE

The purpose of this study is to evaluate the utility and feasibility of abdominal ultrasound (US) in blunt trauma patients.

DESIGN

This prospective study examined the operational issues and the diagnostic accuracy of US in selected blunt trauma patients triaged to a Level 1 trauma center.

MATERIALS AND METHODS

All patients were evaluated by an attending trauma surgeon and our usual criteria for objective evaluation of the abdomen were applied. US was performed by US technicians and interpreted by the trauma surgeon. We prospectively evaluated the availability (time to arrival), the ease with which the US could be integrated into the resuscitation (minutes to start after arrival), and the time required to perform the study. The US results were compared to diagnostic peritoneal lavage and computed tomography findings, clinical course, operative findings, and to repeat US examinations to determine sensitivity, specificity, and usefulness.

MEASUREMENTS AND MAIN RESULTS

A total of 800 US studies were performed over 15 months. In four cases (0.5%), the US was incomplete for technical reasons. The results in the remaining 796 studies were as follows: [table: see text] The average time to arrival of the US was 17.3 minutes (range 0-120) and the average minutes to start after arrival was 7.0 (range 1-49). The average time required to perform the study was 10.6 minutes (range 2-26).

CONCLUSIONS

This study demonstrates that US can be obtained rapidly, integrated into the resuscitation, and completed quickly. US provides a highly accurate, noninvasive method to evaluate the abdomen in the blunt trauma patient, and has supplanted the previously used methods at this institution.

Use of ultrasonography for the evaluation of pregnant trauma patients

The expeditious diagnosis and management of the pregnant trauma patient is essential for the survival of both the mother and fetus. The rapid trauma ultrasound examination, which has been accurately utilized by trauma surgeons and emergency physicians, may have a tremendous impact on the timely identification of acute intraperitoneal injuries and, potentially, on the evaluation of fetal viability in the pregnant trauma patient. This report describes our experience with the rapid trauma ultrasound examination in the management of three pregnant trauma patients and outlines the potential advantages and limitations of the procedure.