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

Blunt abdominal trauma: should US be used to detect both free fluid and organ injuries?

PURPOSE

To evaluate abdominal ultrasonography (US) for indirect (with free fluid analysis only) and direct (with free fluid and parenchymal analysis) detection of organ injury in patients with blunt abdominal trauma, with findings at computed tomography (CT) and/or surgery as the standard of diagnosis.

MATERIALS AND METHODS

Abdominal US was performed at hospital admission in consecutive patients with blunt abdominal trauma. The presence of free peritoneal fluid and organ injury were recorded and compared with results of abdominal CT in all hemodynamically stable patients. When US results were considered false-negative for free fluid or organ injury compared with CT results, repeat US was performed within 6 hours. Admission and second US results were compared with CT and/or surgical results to determine sensitivity, specificity, negative predictive value, and positive predictive value of US with regard to the presence of free intraperitoneal fluid and/or organ injury.

RESULTS

Two hundred five hemodynamically stable patients underwent abdominal US and CT. CT revealed free fluid in 83 patients and organ injury in 99. Thirty-one (31%) of 99 patients with organ injury did not have free fluid at CT. Three (10%) of the 31 patients required surgery or angiographic embolization. The sensitivity of admission US was 93% (77 of 83 cases) for the diagnosis of free fluid, 41% (39 of 99) for directly demonstrating organ injury, and 72% (71 of 99) for suggesting organ injury by means of both free fluid and organ analysis. At second US, these sensitivities were 96% (80 of 83 cases), 55% (54 of 99) and 84% (83 of 99), respectively.

CONCLUSION

US is highly sensitive for the detection of free intraperitoneal fluid but not sensitive for the identification of organ injuries. In hemodynamically stable patients, the value of US is mainly limited by the large percentage of organ injuries that are not associated with free fluid.

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.

Clinical importance of intraperitoneal fluid in patients with blunt intra-abdominal injury

The purpose of this study was to determine the prevalence of intraperitoneal fluid (IF) in blunt trauma patients with intra-abdominal injuries, to determine the rate of exploratory laparotomy in patients with and without IF, and to identify the location of this IF. We retrospectively reviewed the records of 604 patients with intra-abdominal injuries after blunt trauma who were admitted to a level 1 trauma center over a 42-month period. Patients were considered to have intra-abdominal injuries if an injury to the spleen, liver, urinary tract, pancreas, adrenal glands, gallbladder, or gastrointestinal tract was identified on abdominal computed tomography (CT) or at exploratory laparotomy. Patients were considered to have IF if fluid was identified on abdominal CT or during exploratory laparotomy. In patients undergoing abdominal CT or abdominal ultrasound (US), the specific location of the IF was identified. Four hundred forty-three (73%, 95% confidence interval [CI] 69 - 77%) of the 604 patients with intra-abdominal injuries had IF. Patients with IF had an increased risk of laparotomy (344/443 [78%] v 44/161 [27%], odds ratio = 9.2, 95% CI 6.1-13.9). Of the 539 patients undergoing abdominal CT or abdominal US, IF was identified in 389 (72%) and was visualized in the following locations: 258 of 389 (66%) in Morison's pouch, 216 of 389 (56%) in the left upper quadrant, 187 of 389 (48%) in the pelvis, and 139 of 390 (36%) in paracolic gutters. Three patients with IF visualized solely in the paracolic gutters underwent laparotomy. The majority of patients with intra-abdominal injuries have IF, and these patients are more likely to undergo laparotomy. Morison's pouch is the most common location for IF to be detected with radiologic imaging. However, visualization of the paracolic gutters with abdominal US may detect IF in patients with intra-abdominal injuries that would otherwise not be detected by US.

The Role of Positive Examinations in Training for the Focused Assessment Sonogram in Trauma (FAST) Examination

The purpose of this study is to determine whether the inclusion of known positive patients to the practical portion of a Focused Assessment Sonogram in Trauma (FAST) training course improves overall training and increases FAST accuracy. This is a prospective double-blind design. Original course participants (PRE) underwent a 2-hour didactic session and practicum with ten normal volunteers. Modified course participants (POST) additionally imaged five peritoneal dialysis (PD) patients to simulate positive examinations. The practitioners (six PRE and five POST) were compared as to their ability to detect and quantify intraperitoneal fluid (0–2000 cc) in nine PD patients during a double-blind prospective examination. Test results were reported as positive or negative. Positive results were further quantified by volume. Each practitioner performed ten examinations. Data for inexperienced clinicians are presented. Sensitivity for detecting ≤750 cm3 was 45 per cent PRE and 87 per cent POST ( P = 0.02). Accuracy in quantifying volume within 250 cm3 was 38 per cent PRE and 44 per cent POST (not significant). FAST accuracy for inexperienced sonographers—particularly in diagnosing smaller volumes—can be improved significantly by including positive studies in training. Exposure to positive FAST examinations during training improves the learning curve. With the growing dependency on FAST to accurately triage blunt abdominal trauma safe and effective FAST training should consist of didactic education and a practical portion that includes positive studies. When screened properly PD patients can be used effectively to demonstrate positive FAST studies.

Surgeon-performed focused assessment with sonography for trauma as an early screening tool for pregnancy after trauma

BACKGROUND

Incidental pregnancy in trauma patients is associated with a high fetal mortality. Because of quality assurance reasons, many trauma centers have eliminated the rapid urine pregnancy screen. We sought to determine the utility and impact of the initial ultrasound examination in the diagnosis of pregnancy in female trauma patients.

METHODS

Data were analyzed for all female trauma patients in whom pregnancy was diagnosed during a 5-year period.

RESULTS

One hundred one (70%) of 144 pregnant women had an initial ultrasound examination. Eighteen patents had newly diagnosed pregnancies, of whom 8 of 9 patients (89%) at > or = 8 weeks' gestation were diagnosed by the initial ultrasound. This directly contributed to a significant decrease in the amount of radiation exposure (p < 0.001) compared with patients diagnosed by serum beta-human chorionic gonadotropin.

CONCLUSION

An initial ultrasound examination should be considered in all female trauma patients of reproductive age. This may help to promote a reduction in fetal radiation exposure.

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.

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.

Complementary roles of diagnostic peritoneal lavage and computed tomography in the evaluation of blunt abdominal trauma

OBJECTIVE

To assess in randomized prospective format sensitivity, laparotomy rate, and cost-effectiveness of using diagnostic peritoneal lavage (DPL) in a complementary role with computed tomography (CT) in the evaluation of blunt abdominal trauma.

METHODS

Blunt trauma patients greater than 18 years of age were eligible for entry in the study. The study period was from February 1999 to July 2000 at an urban Level I trauma center. All patients were hemodynamically stable upon study entry and had abdominal tenderness with Glasgow Coma Scale (GCS) scores > 13 or GCS < 14. Patients were randomized to a DPL arm (DPL-CT) versus a CT arm. If randomized to the CT arm, patients underwent abdominal/pelvis CT. If CT was positive for solid organ injury, patients were observed. If free fluid was identified on CT without solid organ injury, patients were explored. If randomized to DPL-CT, patients underwent closed infraumbilical DPL, except pelvic fractures that were done with the open supraumbilical technique. If the DPL result was > 20,000 RBCs/mm3, patients underwent abdominal/pelvis CT. If the CT following DPL was consistent with solid organ injury, patients were observed. If the CT following DPL identified free fluid without solid organ injury and DPL was > 100,000 RBCs/mm3, patients were explored.

RESULTS

Two hundred fifty-two patients were entered; 127 patients were randomized to DPL-CT and 125 to CT. Of the 125 patients randomized to CT, 102 (82%) CT scans were negative, 19 (15%) were positive for solid organ injury, and 3 (2%) had free fluid. Three (2%) of the initial negative CT scan patients underwent delayed laparotomy for missed injuries. Of the 127 patients randomized to DPL-CT, 26 (20%) required CT scan, of which 13 (10%) were positive for solid organ injury and 13 (10%) for free fluid. Positive DPL results that were indications for CT ranged from 21,000 to 1 million RBCs/mm3. Eight of the 13 DPL-CT patients with free fluid on CT had DPL results less than 100,000 RBCs/mm3 and did not require laparotomy. There were no known missed injuries in the DPL-CT arm. Seven (6%) laparotomies were performed in the DPL-CT arm and 10 (8%) in the CT arm. The average cost to the patient for abdominal evaluation in the CT arm was 1611 dollars and 650 dollars in the DPL-CT arm.

CONCLUSION

Screening DPL with complementary CT has a low nontherapeutic laparotomy rate and is a sensitive and cost-effective method for the evaluation of blunt abdominal trauma.

Aeromedical trauma sonography by flight crews with a miniature ultrasound unit

BACKGROUND

While ultrasound has become an established diagnostic modality in trauma care, no study has evaluated its use in the prehospital setting.

OBJECTIVE

To examine the use of the focused abdominal sonography for trauma (FAST) exam in the prehospital setting.

METHODS

After a three-hour training session in the FAST exam, the nonphysician flight team of an emergency medical services (EMS) helicopter program attempted a FAST exam on trauma patients to determine the feasibility of such an intervention.

RESULTS

The majority (83%) of the 71 patients entered suffered blunt trauma. FAST exams could not be performed in 34 patients (48%) due to insufficient time (67%), inadequate patient access, or combativeness. Technical difficulties (difficult screen visualization due to ambient lighting, battery failure, and machine malfunction) prevented scanning in seven (19%) of the 37 in whom it was attempted. In those in whom scanning was successful, the pelvic view was most commonly obtained followed by the right upper quadrant (RUQ) and left upper quadrant (LUQ).

CONCLUSION

Significant advances in training, technology, and/or patient access will be necessary for aeromedical FAST to be feasible.

Bedside echocardiography by emergency physicians

STUDY OBJECTIVE

Timely diagnosis of a pericardial effusion is often critical in the emergency medicine setting, and echocardiography provides the only reliable method of diagnosis at the bedside. We attempt to determine the accuracy of bedside echocardiography as performed by emergency physicians to detect pericardial effusions in a variety of high-risk populations.

METHODS

Emergency patients presenting with high-risk criteria for the diagnosis of pericardial effusion underwent emergency bedside 2-dimensional echocardiography by emergency physicians who were trained in ultrasonography. The presence or absence of a pericardial effusion was determined, and all images were captured on video or as thermal images. All emergency echocardiograms were subsequently reviewed by the Department of Cardiology for the presence of a pericardial effusion.

RESULTS

During the study period, a total of 515 patients at high risk were enrolled. Of these, 103 patients were ultimately deemed to have a pericardial effusion according to the comparative standard. Emergency physicians detected pericardial effusion with a sensitivity of 96% (95% confidence interval [CI] 90.4% to 98.9%), specificity of 98% (95% CI 95.8% to 99.1%), and overall accuracy of 97.5% (95% CI 95.7% to 98.7%).

CONCLUSION

Echocardiography performed by emergency physicians is reliable in evaluating for pericardial effusions; this bedside diagnostic tool may be used to examine specific patients at high risk. Emergency departments incorporating bedside ultrasonography should teach focused echocardiography to evaluate the pericardium.

Does the presence of ultrasound really affect computed tomographic scan use? A prospective randomized trial of ultrasound in trauma

OBJECTIVE

There is a paucity of evidence demonstrating that emergency department (ED) ultrasound changes clinical practice in trauma patients. We hypothesized that the presence of ultrasound would affect clinical decision making as evidenced through abdominal computed tomographic (CT) scan use in blunt multiple trauma patients.

METHODS

This study used a prospective randomized format in an urban county ED with Level II trauma center status (ED census, 72,000 patients per year). Participants were patients with multiple blunt injuries meeting trauma center triage criteria. Patients were randomized to receive either abdominal ultrasound or no ultrasound (control) during initial ED resuscitation. The primary outcome variable was use of abdominal CT scan in patients with and without ultrasound.

RESULTS

Two hundred eight patients were enrolled. The mean age was 40 +/- 18 years, and 62% were men. Mechanism of injury was motor vehicle crash, 56%; automobile versus pedestrian, 18%; motorcycle crash, 16%; falls, 10%; and other, 10%. One hundred four ultrasound and 104 control patients were analyzed. There were no apparent differences between ultrasound and control groups in demographics, injury type, or Injury Severity Score. Fifty-four of 104 (52%) of the control group received abdominal CT scans versus 37 of 104 (36%) abdominal CT scans for the ultrasound group; mean difference in proportions was 15.9 (p < 0.01; 95% confidence interval, 2.6-29.1).

CONCLUSION

In this trial, the routine use of abdominal ultrasound in the evaluation of patients with multiple blunt injuries resulted in significantly fewer abdominal CT scans being obtained. A larger trial is needed to more clearly define the clinical and financial impact of ultrasound in the management of blunt abdominal trauma.

Accuracy of emergency department bedside ultrasonography

OBJECTIVES

To determine which focused ultrasound examinations can be interpreted accurately by emergency physicians who have limited training and experience. To determine whether image quality and/or the operator's level of confidence in the findings correlates with accurate scan interpretation.

METHODS

A prospective sample of consenting adult emergency department patients with the conditions was selected for study. Scans were performed by emergency physicians who had attended a 3-day focused ultrasound examinations instruction course. All scans were videotaped and subsequently reviewed by a radiologist. Accuracy was determined by comparing the emergency physicians scan interpretation with preselected gold standards. Chi-squared tests were employed to determine if the individual performing the scan, the type of scan, patient's body habitus, image quality and/or operator confidence were reliable predictors of accuracy.

RESULTS

Between September 1997 and January 1999, 221 scans were studied. Accuracy varied widely depending on the type of scan performed: aortic scans were 100% accurate whereas renal scans had 68% accuracy. On bivariate analyses, there was little variation in the various operators' levels of proficiency and accuracy of interpretation was not associated with patient body habitus, image quality or operator confidence.

CONCLUSIONS

Neophytes can accurately perform and interpret aortic scans; additional training and/or experience appear to be necessary to achieve proficiency in conducting most of the other scans studied. Inexperienced operators are unable to discern whether their scan interpretations will prove accurate.

The routine use of sonography in penetrating torso injury is beneficial

BACKGROUND

Torso sonography (focused assessment with sonography for trauma [FAST]) has been added to our protocols for the evaluation of penetrating torso injury. The purpose of this study was to evaluate our recent experience and determine whether the use of FAST is beneficial.

METHODS

From January 1999 to January 2000, patients with penetrating torso injury and no clinical indication for surgery were evaluated by sonography with a selective use of other investigations. FAST consisted of sonographic views of the peritoneum and/or pericardium to determine the presence or absence of fluid.

RESULTS

During the study period, there were 238 victims of penetrating injury assessed by our trauma service, and sonography was performed in 72 (30%) patients as per our protocols. There were 31 stab, 37 gunshot/shotgun and, and 4 puncture wounds. Thirty-eight patients had peritoneal views, 6 patients had pericardial views, and 28 patients had both pericardial and peritoneal views obtained. Thirteen of 66 patients had free fluid in the peritoneal cavity and 12 of the 13 patients had a therapeutic laparotomy. No peritoneal fluid was seen in 53 of 66 patients, of whom 6 had abdominal injuries, 5 requiring surgery for diaphragm or bowel injuries. The sensitivity of FAST alone for abdominal injury was 67%, specificity was 98%, positive predictive value was 92%, and negative predictive value was 89%. Pericardial fluid was seen in 3 of 34 patients; one had a heart wound and two had negative pericardial windows. All 31 patients without pericardial fluid recovered without surgery.

CONCLUSION

The routine use of sonography in penetrating torso injury is beneficial. The detection of pericardial or peritoneal fluid is clinically useful. However, a negative FAST examination does not exclude abdominal injury, such as a diaphragm or hollow viscus wound, and further investigation or close follow-up is required.

Operative versus nonoperative management of blunt abdominal trauma: Role of ultrasound-measured intraperitoneal fluid levels

This study's objective was to analyze whether the quantity of free intraperitoneal fluid on ultrasonography, alone or in combination with unstable vital signs, is sensitive in determining the need for laparotomy in patients presenting with blunt trauma. Adult patients who presented with blunt abdominal trauma to 2 level I trauma centers were enrolled. Combined intraperitoneal fluid levels (anechoic stripe) of 5 intraperitoneal areas were measured and defined as small (< 1.0 cm), moderate (> 1.0 cm, < 3.0 cm), or large (> 3.0 cm). Unstable vital signs were defined as pulse > 100 bpm or systolic blood pressure < 90 mmHg. Exploratory laparotomy or computed tomography scan confirmed hemoperitoneum. Of 270 patients entered into the study, ultrasound detected free intraperitoneal fluid in 33 patients. Of the 18 patients with a large fluid accumulation, 16 underwent exploratory laparotomy (89% sensitivity), and all 8 patients with unstable vital signs underwent exploratory laparotomy (100% sensitivity). Of the 10 patients with a moderate fluid accumulation, 6 underwent exploratory laparotomy (60% sensitivity), and 4 of the 6 patients with unstable vital signs underwent exploratory laparotomy (67% sensitivity). A large intraperitoneal fluid accumulation on ultrasonography in combination with unstable vital signs, is sensitive for determining the need for exploratory laparotomy in patients presenting with blunt trauma.

Discriminatory power of 3.5 MHz convex and 7.5 MHz linear ultrasound probes for the imaging of traumatic splenic lesions: a feasibility study

BACKGROUND

Ultrasound is a powerful tool for recognition of free fluid after blunt abdominal trauma, whereas its role for detection of organ lesions remains to be defined. The objective of this study was to determine the diagnostic value of different ultrasound transducers for the precise detection of visceral damage rather than its surrogates in case of splenic injury.

METHODS

After a standardized focused abdominal sonogram for trauma protocol to screen for hemoperitoneum, 37 slim, hemodynamically stable subjects with suspected torso trauma were investigated for the extent of parenchymal lesions of the spleen using a 3.5 MHz curved array and a 7.5 MHz linear device. Helical computed tomographic scanning was carried out as the reference standard in all cases.

RESULTS

Twenty patients presented splenic damage. The 7.5 MHz transducer showed higher accuracy than the lower frequency probe for the detection of tissue irregularities (difference in proportions, 16.2%; 95% confidence interval, -1.9%-33.5%). A similar trend was observed for 13 lacerations subsequently progressing to two-timed splenic rupture that required surgery (absolute risk reduction, 8.1%; 95% confidence interval, -7.6%-23.9%). With an observed prevalence of 54% for the presence of splenic injury, organ lacerations could be excluded more confidently using the linear probe (posttest probability, 16% vs. 36%).

CONCLUSION

In slim patients, higher frequency linear ultrasound probes can provide therapy-relevant information on the integrity of splenic parenchyma after blunt abdominal trauma.

Fast education: a comparison of teaching models for trauma sonography

This study's objective was to evaluate the peritoneal dialysis and mannequin simulator models for the hands-on portion of a 4-h focused abdominal sonography for trauma (FAST) course. After an introductory lecture about trauma sonography and practice on normal models, trainees were assigned randomly to two groups. They practiced FAST on one of the two simulator models. After the didactic and hands-on portions of the seminar, FAST interpretation testing revealed mean scores of 82% and 78% for the peritoneal dialysis and mannequin simulator groups, respectively (p = 0.95). Post-course surveys demonstrated mean satisfaction scores for peritoneal dialysis and mannequin simulator models of 3.85 and 3.25, respectively, on a 4-point Likert scale (p = 0.317). A FAST educational seminar, which provides both didactic and hands-on instruction, can be completed in 4 h; the hands-on instruction phase can incorporate both normal models and abnormal simulation models, such as the peritoneal dialysis model and the multimedia mannequin simulator.

Abdominal ultrasound examination in pregnant blunt trauma patients

BACKGROUND

The ability of abdominal ultrasound to detect intraperitoneal fluid in the pregnant trauma patient has been questioned.

METHODS

Pregnant blunt trauma patients admitted to a Level I trauma center during an 8-year period were reviewed. Ultrasound examinations were used to detect intraperitoneal fluid and considered positive if such fluid was identified.

RESULTS

One hundred twenty-seven (61%) of 208 pregnant patients had abdominal ultrasound during initial evaluation in the emergency department. Seven patients had intra-abdominal injuries, and six had documented hemoperitoneum. Ultrasound identified intraperitoneal fluid in five of these six patients (sensitivity, 83%; 95% confidence interval, 36-100%). In the 120 patients without intra-abdominal injury, ultrasound was negative in 117 (specificity, 98%; 95% confidence interval, 93-100%). The three patients without intra-abdominal injury but with a positive ultrasound had the following: serous intraperitoneal fluid and no injuries at laparotomy (one) and uneventful clinical courses of observation (two).

CONCLUSION

The sensitivity and specificity of abdominal ultrasonography in pregnant trauma patients is similar to that seen in nonpregnant patients. Occasional false negatives occur and a negative initial examination should not be used as conclusive evidence that intra-abdominal injury is not present. Ultrasound has the advantages of no radiation exposure.

Ultrasound detection of blunt splenic injury

The purpose of this study was to determine the sensitivity of emergency ultrasound (US) for the detection of blunt splenic injury (BSI), and to describe sonographic parenchymal patterns. Over 3 years, 2138 emergency US were performed, and 162 patients had BSI. CT was performed for 76 patients, and there were 86 laparotomies. Seventy patients (43%) had concomitant intraabdominal injuries. Ultrasound detected free fluid in 109 patients (67%), and parenchymal injury in 31 patients (19%). There were 48 false negative US (30%). Sonographic patterns included a diffuse heterogeneous appearance, hyperechoic and hypoechoic perisplenic crescents, and discrete hypoechoic or hyperechoic areas within the spleen. Overall sensitivity of US for detection of BSI was 69%, but was 86% for grade III or higher injuries. Ultrasound is most sensitive for the detection of grade III or higher BSI based on the presence of haemoperitoneum. Ultrasound may also identify BSI on the basis of parenchymal abnormality, with a diffuse heterogeneous pattern most commonly encountered. Sonographic evaluation for both free fluid and parenchymal injury improves sensitivity of US.

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.

Utilization of FAST (Focused Assessment with Sonography for Trauma) in 1999: Results of a Survey of North American Trauma Centers

Although much has been written about FAST (Focused Assessment with Sonography for Trauma) in the last decade little is known about its present clinical utilization. The purpose of this study was to evaluate and characterize the contemporary utilization of FAST at trauma centers in the United States and Canada. In 1999 trauma directors or their delegates at Level I regional trauma centers in the United States and Canada were surveyed either by fax or phone regarding the present utilization and the future of FAST at their center. The overall survey response rate was 91 per cent with 96 of 105 centers completing the survey. Of the 96 centers surveyed 78 were in the United States and 18 were in Canada. Of the 78 U.S. centers surveyed 62 (79%) routinely use FAST, and it is done by surgeons in 39 per cent, surgeons and emergency departments in 21 per cent, emergency departments in 5 per cent, and radiologists in 35 per cent. Most centers (79%) thought that it sped up their workups, and 89 per cent said it was an advance in patient care. FAST is used in penetrating injury at 58 per cent of centers, and some centers use FAST to assess organ injury. The utilization of diagnostic peritoneal lavage and CT has markedly decreased at many centers. Almost all respondents thought that FAST should be a component of surgery resident training. The utilization of FAST is significantly less in Canada than in the United States ( P < 0.05). Our conclusions are the following. FAST has become routinely used at the majority of the U.S. centers surveyed. FAST is performed by clinicians at 65 per cent of the trauma centers surveyed. The utilization of CT and diagnostic peritoneal lavage has changed. Many centers have broadened the scope of FAST to include the assessment of organ, pediatric, and penetrating injury.

Focused abdominal US in patients with trauma

PURPOSE

To evaluate the accuracy of focused abdominal ultrasonography (US) in detecting abdominal injuries that require in-hospital patient treatment in the setting of blunt abdominal trauma.

MATERIALS AND METHODS

One thousand ninety patients with blunt abdominal trauma were assessed with focused abdominal US within 30 minutes of arrival at the hospital. Focused abdominal US results were positive if intra- or retroperitoneal fluid was detected. Patients with negative US results and no other major injuries were observed in the emergency department for 12 hours before discharge. Patients who deteriorated clinically after negative initial US underwent repeat US and/or emergency abdominopelvic computed tomography (CT). Patients with positive or indeterminate US results underwent emergency abdominopelvic CT.

RESULTS

Nine hundred seventy-four (89%) patients had negative focused abdominal US results; eight of these underwent CT. Sixty-six (6%) had positive US results. Four (0.4%) had false-negative and 19 (1.7%) had false-positive US results. Twenty-seven (2.5%) had indeterminate US results; of these, five (18.5%) had positive CT results. One hundred twenty-four (11.4%) required emergency CT. After indeterminate cases were excluded, focused abdominal US had 94% sensitivity, 98% specificity, 78% positive predictive value, 100% negative predictive value, and 95% accuracy.

CONCLUSION

Focused abdominal US has a high negative predictive value for major abdominal injury in patients with blunt abdominal trauma.

Imaging in abdominal trauma

Prompt recognition and timely intervention both play a crucial role in managing patients with blunt abdominal trauma. In most cases of multiply injured patients, where physical examination is indeterminate, a rapid and accurate screening method is a valuable adjunct for care-providers. Through the years, different imaging techniques have been utilized for this purpose; among them are diagnostic peritoneal lavage (DPL), ultrasonography (US) and computed tomography (CT). Proponents of each modality have their own beneficial reasons for adopting that particular method of imaging. Needless to say, despite the high sensitivity and specificity values cited for each, all the methods have their own limitations. After having reviewed the advantages and disadvantages of these three modalities, this article suggests that there is not one single modality that is considered the best. Rather, all three can be complementary and the use of each can be appropriate for a particular subset of patients, given a particular clinical situation, and taking into account the resources available.

Trauma ultrasound feasibility during helicopter transport

OBJECTIVE

To evaluate the feasibility of performing a standard four-view focused abdominal sonography for trauma (FAST) examination during helicopter transport using a hand-carried ultrasound machine.

METHODS

In this prospective observational study, actual and simulated trauma patients were evaluated using the SonoSite 180 ultrasound machine by two air transport programs serving Level I trauma centers. FAST examinations were performed in flight by emergency medicine faculty, residents, flight nurses, and ultrasound technologists, who rated the difficulty posed by various factors using Likert scales (0 = not difficult to 5 = impossible). BK 117, Bell 230, and BO 105 medical helicopters flew in all aviating modes. Pilots were queried regarding avionics variations throughout the flights.

RESULTS

Ten flight sonographers performed 21 FAST examinations on 14 patients (five actual, nine simulated). The median Likert value for each parameter was 0 except for patient position, which was 1 (somewhat difficult). Interquartile ranges were 0-0 for vibration, bedding, IV catheters, monitor cables, and ventilator; 0-0.5 for backboard straps; and 0-1 for sunlight, patient position, spider straps, gurney straps, and clothing. Mean examination duration, was 3.0 minutes (range 1.5 to 5.5 minutes, SD 1.3). Pilots reported no effects on avionics in any flight mode.

CONCLUSION

The FAST examination using the SonoSite 180 in flight was rated by 10 evaluators to be performed easily. Examinations were conducted quickly and did not interfere with helicopter avionics. This digital ultrasound machine is the first one small enough to be used in most medical helicopters.

Comparison of US utilization and technical costs before and after establishment of 24-hour in-house coverage for US examinations

PURPOSE

To compare data regarding the cost and number of ultrasonographic (US) examinations performed for 6 months, before and after institution of 24-hour in-house sonographer coverage.

MATERIALS AND METHODS

Data for a 6-month period during which US services were provided by a sonographer on call from 11 PM to 7 AM were compared with data for a 6-month period during which a sonographer was in house during this shift.

RESULTS

With 11 PM to 7 AM on-call coverage, the sonographers performed 147 examinations in a 6-month period, an average of 0.81 examination per shift. After institution of in-house coverage for this shift, 792 US examinations were performed in 6 months, an average of 4.3 examinations per shift. The cost for 11 PM to 7 AM in-house sonographer coverage for 6 months was approximately $16,000 more than that for on-call coverage. This cost would be offset by revenues from one additional examination per night. The cost per examination for the 11 PM to 7 AM shift decreased from $124.70 to $43.33.

CONCLUSION

At the authors' institution, 24-hour in-house sonographer coverage resulted in additional cost, which was offset by revenues from additional examinations. There was nearly a fivefold increase in the number of US examinations performed per shift. These examinations were performed more expediently, enabling more rapid patient triage.

Ultrasound training for emergency physicians--a prospective study

OBJECTIVES

Bedside ultrasound examination by emergency physicians (EPs) is being integrated into clinical emergency practice, yet minimum training requirements have not been well defined or evaluated. This study evaluated the accuracy of EP ultrasonography following a 16-hour introductory ultrasound course.

METHODS

In phase I of the study, a condensed 16-hour emergency ultrasound curriculum based on Society for Academic Emergency Medicine guidelines was administered to emergency medicine houseofficers, attending staff, medical students, and physician assistants over two days. Lectures with syllabus material were used to cover the following ultrasound topics in eight hours: basic physics, pelvis, right upper quadrant, renal, aorta, trauma, and echo-cardiography. In addition, each student received eight hours of hands-on ultrasound instruction over the two-day period. All participants in this curriculum received a standardized pretest and posttest that included 24 emergency ultrasound images for interpretation. These images included positive, negative, and nondiagnostic scans in each of the above clinical categories. In phase II of the study, ultrasound examinations performed by postgraduate-year-2 (PGY2) houseofficers over a ten-month period were examined and the standardized test was readministered.

RESULTS

In phase I, a total of 80 health professionals underwent standardized training and testing. The mean +/- SD pretest score was 15.6 +/- 4.2, 95% CI = 14. 7 to 16.5 (65% of a maximum score of 24), and the mean +/- SD posttest score was 20.2 +/- 1.6, 95% CI = 19.8 to 20.6 (84%) (p < 0. 05). In phase II, a total of 1,138 examinations were performed by 18 PGY2 houseofficers. Sensitivity was 92.4% (95% CI = 89% to 95%), specificity was 96.1% (95% CI = 94% to 98%), and overall accuracy was 94.6% (95% CI = 93% to 96%). The follow-up ultrasound written test showed continued good performance (20.7 +/- 1.2, 95% CI = 20.0 to 21.4).

CONCLUSIONS

Emergency physicians can be taught focused ultrasonography with a high degree of accuracy, and a 16-hour course serves as a good introductory foundation.

Role of emergency medicine physicians in US performed in patients in the emergency department: how substantial is their participation?

PURPOSE

To determine the extent to which emergency medicine physicians have assumed responsibility for performing and interpreting ultrasonographic (US) studies in emergency departments (EDs) in the United States.

MATERIALS AND METHODS

The national 1997 Medicare Part B database was searched by using standard US procedure codes, location codes, and physician specialty codes. The authors determined how many US studies were performed in EDs and what percentage of those studies were performed by emergency medicine physicians, radiologists, or other physicians.

RESULTS

During 1997, 234,820 ED US studies within nine major examination categories were performed in Medicare patients nationwide. Emergency medicine physicians performed 1,551 (0.7%) of these studies. When echocardiographic examinations were excluded, emergency medicine physicians performed 458 (0.2%) of the remaining total of 196,158 studies.

CONCLUSION

Although emergency medicine physicians have claimed to be actively involved in ED US on a broad scale, the data reveal that their involvement in 1997 was minimal. This raises doubt as to whether they can properly train their residents to perform US or maintain their own competence at acceptable levels.

Conservative management of penetrating torso trauma

Trauma has evolved as a specialty of its own over the past two decades, and has been the subject of much research and a huge number of trials, many of which are ongoing. As a result, it is now possible to apply an evidence-based practice to many trauma scenarios. The management of penetrating injuries to the chest or abdomen has traditionally followed a policy of emergency surgery as the first course of action. This has now shown to be unnecessary in many cases, particularly with the advances in diagnostic tests and imaging modalities. A large number of cases of penetrating torso trauma may require an operation at some stage, but obtaining the clearest diagnostic picture and optimizing the clinical condition of the patient before this undertaking will result in improved outcome. A selective approach to emergency surgery, with its attendant difficulties, is now recommended

Institutional and individual learning curves for focused abdominal ultrasound for trauma: cumulative sum analysis

OBJECTIVE

To evaluate both institutional and individual learning curves with focused abdominal ultrasound for trauma (FAST) by analyzing the incidence of diagnostic inaccuracies as a function of examiner experience for a group of trauma surgeons performing the study in the setting of an urban level I trauma center.

SUMMARY BACKGROUND DATA

Trauma surgeons are routinely using FAST to evaluate patients with blunt trauma for hemoperitoneum. The volume of experience required for practicing trauma surgeons to be able to perform this examination with a reproducible level of accuracy has not been fully defined.

METHODS

The authors reviewed prospectively gathered data for all patients undergoing FAST for blunt trauma during a 30-month period. All FAST interpretations were validated by at least one of four methods: computed tomography, diagnostic peritoneal lavage, celiotomy, or serial clinical evaluations. Cumulative sum (CUSUM) analysis was used to describe the learning curves for each individual surgeon at target accuracy rates of 85%, 90%, and 95% and for the institution as a whole at target examination accuracy rates of 85%, 90%, 95%, and 98%.

RESULTS

Five trauma surgeons performed 546 FAST examinations during the study period. CUSUM analysis of the aggregate experience revealed that the examiners as a group exceeded 90% accuracy at the outset of clinical examination. The level of accuracy did not improve with either increased frequency of performance or total examination experience. The accuracy rates observed for each trauma surgeon ranged from 87% to 98%. The surgeon with the highest accuracy rate performed the fewest examinations. No practitioner demonstrated improved accuracy with increased experience.

CONCLUSIONS

Trauma surgeons who are newly trained in the use of FAST can achieve an overall accuracy rate of at least 90% from the outset of clinical experience with this modality. Interexaminer variations in accuracy rates, which are observed above this level of performance, are probably related more to issues surrounding patient selection and inherent limitations of the examination in certain populations than to practitioner errors in the performance or interpretation of the study.

The focused abdominal sonography for trauma (FAST) examination: considerations and recommendations for training physicians in the use of a new clinical tool

Focused abdominal sonography for trauma (FAST) is being used by growing numbers of emergency physicians and surgeons because it has proven to be an accurate, rapid, and repeatable bedside test for evaluating abdominal trauma victims. Controversy exists about the optimal means of FAST education and the number of examinations necessary to demonstrate competency. Most FAST educators agree that FAST education should consist of three phases: didactic, practical, and experiential. This article summarizes options and preliminary recommendations suitable for developing a FAST curriculum.

A preliminary evaluation of emergency ultrasound in the setting of an emergency medicine training program

In this article we seek to evaluate the diagnostic accuracy of emergency physicians performing emergency ultrasonography in the setting of an emergency medicine training program. A prospective observational study was performed at an inner city Level I trauma center with an emergency medicine residency training program. From July 1994 to December 1996 a convenience sample of ultrasound exams was recorded. The diagnostic quality ("acceptable or technically limited") was determined by a board-certified cardiologist or radiologist with fellowship training in ultrasonography. The emergency department interpretations were then compared to those of the blinded cardiologist or radiologist. Four hundred and fifty-six ultrasound examinations were videotaped and entered into the study; 408 (89%) of the studies performed were determined to be "acceptable." The diagnostic accuracy (sensitivity, specificity, positive and negative predictive values) of these studies were as follows: cardiac, to rule out effusion (n = 67; 0.83, 0.98, 0.88, 0.98); transabdominal, to rule out abdominal aortic aneurysms (AAA), cholelithiasis, or free peritoneal fluid (n = 263; 0.91, 0.89, 0.88, 0.92); renal, to rule out hydronephrosis (n = 45; 0.94, 0.96, 0.94, 0.96); pelvic, to rule in intrauterine pregnancy (n = 33; 1.0, 0.90, 0.96, 1.0). The 48 "technically limited studies" included: 39 transabdominal (33 gallbladder, 1 abdominal aortic aneurysm, 5 free peritoneal fluid), 6 cardiac, 2 renal, and 1 pelvic ultrasound. This study suggests that emergency physicians with a minimal amount of training display acceptable technical skill and interpretive acumen in their approach to emergency ultrasonography.

Serial abdominal ultrasound in the setting of trauma

Ultrasound is gaining wide acceptance in Emergency Medicine as an inexpensive and accurate examination modality. One of the leading uses of this technology is in the initial assessment of the trauma patient, where the ultrasound examination is often used to determine the need for immediate laparotomy or further diagnostic study. We present a series of four patients, all of whom sustained blunt or penetrating abdominal trauma. In each case, the initial screening abdominal ultrasound was negative for free intraperitoneal (i.p.) fluid but, when repeated by the same practitioner, became positive. These cases demonstrate the need for serial ultrasounds in evaluating the patient with abdominal trauma. Future studies of trauma ultrasound should investigate the utility of serial sonographic examinations.

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.

A comparison of emergency medicine ultrasound training with guidelines of the Society for Academic Emergency Medicine

STUDY OBJECTIVES

To compare the current state of emergency medicine residency ultrasound training with guidelines for that training from the Society for Academic Emergency Medicine (SAEM).

METHODS

A brief questionnaire was sent to program directors from 119 emergency medicine residency programs in the United States. Responses were compared with the SAEM guidelines for clinical experience (150 total ultrasounds) and didactic experience (40 hours of didactic instruction).

RESULTS

The overall response rate was 92%. Seventy-six (69%) of the programs own an ultrasound machine (ownership defined as 24-hour availability and complete discretion over use). Of these, 12 (16%) indicated that their average 1998 graduate had done at least 150 total ultrasound scans during residency, although none of the programs had average numbers that exceeded the minimum guidelines for all 4 procedure categories. Information on didactic curriculum was available from 74 ultrasound-owning programs: the duration was 0 to 20 hours in 49 (66%), 20 to 40 hours in 19 (26%), and 40 to 100 hours in 6 (8%). Only 1 program's average graduate met or exceeded the SAEM guidelines for both didactic and clinical training.

CONCLUSION

Most emergency medicine residency programs own at least 1 ultrasound machine, with more than half of these obtaining their first machine within the past 3 years. Only 1 program currently meets SAEM training guidelines.

Hemoperitoneum as the sole indicator of abdominal visceral injuries: a potential limitation of screening abdominal US for trauma

PURPOSE

To determine, at screening ultrasonography, the prevalence, severity, and clinical outcome of clinically important abdominal visceral injuries, without associated hemoperitoneum, that result from blunt abdominal trauma.

MATERIALS AND METHODS

Computed tomography (CT) was performed at admission in 466 patients with visceral injury. A retrospective review was performed of findings from surgery and contrast material-enhanced spiral and conventional CT performed to verify abdominal visceral injuries in 467 (4%) of 11,188 patients with blunt trauma. These patients were admitted to a level 1 trauma center over 33 months to determine the presence of hemoperitoneum and to identify the grade of injury. Medical records of patients with abdominal visceral injury without hemoperitoneum were reviewed for the management required and for results of focused abdominal sonography for trauma (FAST).

RESULTS

A total of 575 abdominal visceral injuries were identified at CT and/or surgery. Findings of CT at admission (n = 156) and of surgery (n = 1) revealed no evidence of hemoperitoneum in 157 (34%) patients with abdominal visceral injury; 26 (17%) of whom also had negative FAST studies. Abdominal visceral injuries diagnosed in patients without hemoperitoneum included 57 (27%) of 210 splenic injuries, 71 (34%) of 206 hepatic injuries, 30 (48%) of 63 renal injuries, four (11%) of 35 mesenteric injuries, and two (29%) of seven pancreatic injuries. Surgical and/or angiographic intervention was required in 26 (17%) patients without hemoperitoneum.

CONCLUSION

Reliance on the presence of hemoperitoneum as the sole indicator of abdominal visceral injury limits the value of FAST as a screening diagnostic modality for patients who sustain blunt abdominal trauma.

An algorithm to reduce the incidence of false-negative FAST examinations in patients at high risk for occult injury. Focused Assessment for the Sonographic Examination of the Trauma patient

BACKGROUND

The Focused Assessment for the Sonographic Examination of the Trauma patient (FAST) sequentially surveys for the presence or absence of blood in dependent abdominal regions including the right upper quadrant, left upper quadrant, and the pelvis. But it does not readily identify intraparenchymal or retroperitoneal injuries, and a CT scan of the abdomen may be needed to reduce the incidence of missed injuries. We hypothesized that select patients who are considered high risk for occult injuries should undergo a CT scan of the abdomen when the FAST is negative so that occult injuries can be detected.

STUDY DESIGN

An algorithm was prospectively tested for the evaluation of select injured patients over a 3 1/2-year period. Entrance criteria included adult patients with a blunt mechanism of trauma, a negative FAST examination, and a spine fracture (with or without cord injury), or a pelvic fracture. Trauma team members performed the FAST on patients during the Advanced Trauma Life Support secondary survey. Data recorded included the patient's mechanism and type of injury, the results of the FAST and CT scan examinations, operative or postmortem findings or both, and patient outcomes. Patients with spine injuries were grouped according to spine level and the presence or absence of neurologic deficit. The patients with pelvic fractures were grouped according to the Young and Resnick classification.

RESULTS

One hundred two of 1,490 patients (6.8%) who had FAST examinations were entered into this study. Thirty-two patients (30.5%) had spine injuries, with only one false-negative ultrasound result. Seventy patients (68.6%) had pelvic fractures with 13 false-negative ultrasound results: 11 ring (9 from motor vehicle crashes, 2 from pedestrians struck), 1 acetabular, and 1 isolated pelvic fracture. Nine patients underwent nonoperative management for solid organ injuries, and 4 patients needed surgery.

CONCLUSIONS

Based on these preliminary data, we conclude that patients with pelvic ring-type fractures should have CT scans of the abdomen because of the higher yield for occult injuries.

Should UK emergency physicians undertake diagnostic ultrasound examinations?

From the published evidence there is no doubt that emergency physicians in America can undertake focused ultrasound examinations and that, by extrapolation, this would also be the case for UK emergency physicians. If this skill is to become part of the diagnostic armamentarium of the emergency physician, however, it needs to be demonstrated to be cost effective compared with the alternatives already available to the hospital. Trials to test for this benefit should adopt a hospital and not an emergency department perspective if the results are to influence health policy and specialty training.

Bowel and mesenteric injury: evaluation with emergency abdominal US

PURPOSE

To assess emergency ultrasonography (US) for detection of bowel and mesenteric injury from blunt trauma.

MATERIALS AND METHODS

For 3 years, prospective data on all patients undergoing emergency US were recorded. Patients with bowel and mesenteric injury were identified, and physical examination, laboratory, computed tomographic (CT), and intraoperative findings were compared with prospective data.

RESULTS

From January 1995 to January 1998, emergency US was performed in 1,686 patients; 71 patients had bowel and mesenteric injury. Forty-one examinations were true-positive (i.e., with free fluid), and 30 were false-negative. Twenty-five of the 41 patients with true-positive US results had concomitant injuries that may have accounted for the free fluid, including liver, spleen, pancreas, gallbladder, kidney, and/or bladder injuries. The remaining 16 patients had isolated bowel and mesenteric injury. Bowel and mesenteric damage was identified intraoperatively in 70 patients. Twenty-nine of 30 patients with false-negative US examinations had abdominal tenderness. Sixteen patients with false-negative US results had bowel and mesenteric injury that was detected 12 or more hours after initial scanning.

CONCLUSION

Free fluid in the abdomen is not detected in the majority of patients with isolated bowel and mesenteric injury. For clinical suspicion of bowel and mesenteric injury, observation, serial physical abdominal examination, and CT may be helpful in diagnosing this condition.

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.

Echocardiography in the Emergency Department: From the Perspective of the Emergency Physician and the Cardiologist

Echocardiography performed in the emergency department must adapt to this new setting for noninvasive diagnostic testing. Emergency physicians require echocardiography to provide rapid diagnosis in life-threatening emergencies. New initiatives are being proposed by emergency physicians in the delivery of this test. Cardiologists now use echocardiography in the emergency department to make the diagnosis of heart disease earlier and with greater accuracy.

Evaluation of the patient with blunt abdominal trauma: an evidence based approach

Patients with blunt abdominal trauma present a special challenge to the emergency physician. Physical examination is often unreliable, even if the patient is awake, and the frequent co-existence of head injury exacerbates this problem. This article examines the evidence basis of three diagnostic modalities in evaluating blunt abdominal trauma: DPL (the time-honored test); CT scanning (the current standard of care); and abdominal sonography (the emerging standard--especially for examination conducted in the trauma room). A proposed algorithm for the appropriate use of these modalities is also presented.

The efficacy of focused abdominal sonography for trauma (FAST) as a screening tool in the assessment of injured children

PURPOSE

Focused abdominal sonography for trauma (FAST) is rapidly gaining acceptance as an effective and accurate way to determine significant abdominal injury. The authors analyzed their experience in 94 children with blunt torso trauma (BTT) to assess FAST accuracy in identifying operative lesions and utility in avoiding additional diagnostic studies.

METHODS

The authors' pediatric trauma registry was queried to identify all children with BTT who underwent FAST as part of their initial trauma assessment. Accuracy was determined by calculating sensitivity and specificity using as true positives those children with lesions requiring operative intervention. Utility was analyzed by reviewing the need for additional diagnostic or therapeutic intervention in those patients with negative FAST findings and negative clinical examination findings.

RESULTS

Three of these 94 children had lesions that required laparotomy. One was FAST positive (sensitivity, 33.3%). One of two FAST-negative patients was a child in extremis from a suspected thoracic aortic disruption, and the other was a child with an intestinal disruption in whom peritoneal signs developed 24 hours after injury. Of 89 FAST-negative children, 20 underwent abdominal computed tomography (CT) at the surgeon's request. Eight of these patients were found to have minor visceral injury that required no further treatment. The remaining 69 included the child with the aortic disruption and 68 patients whose hospital course was uneventful and required no additional intervention.

CONCLUSIONS

From the practical perspective of indicating need for operative intervention in BTT, FAST has a high specificity (95%); however, it is not particularly sensitive (33%). This excellent specificity in combination with clinical examination underscores FAST utility by avoiding unnecessary diagnostic intervention in 72% of the patients in this study.

Increased Efficiency and Cost-Effectiveness in the Evaluation of the Blunt Abdominal Trauma Patient with the Use of Ultrasound

The efficacy and effectiveness of ultrasound (US) in evaluating patients suspected of having blunt abdominal trauma are near that of computed tomography (CT) and diagnostic peritoneal lavage (DPL). Because no cost-effectiveness study has been reported, the purpose of this study was to demonstrate that US is more efficient and cost-effective than CT/DPL in evaluating blunt abdominal trauma. Over a 9-month period, 331 patients suspected of sustaining blunt abdominal trauma were evaluated at a Level I trauma center by US, CT, and/or DPL. Cost data and time to disposition were determined for analysis. The sensitivity, specificity, and accuracy of US were similar to those reported in previous studies. There was a significant difference in time to disposition with the US group being significantly lower (P = 0.001). The total procedural cost was 2.8 times greater for the CT/DPL group than for the US group. US is not only effective in diagnosing blunt abdominal trauma, but it is also more efficient and cost-effective than is CT/DPL.