Sonography in blunt abdominal trauma: a preliminary progress report

Hemoperitoneum score helps determine need for therapeutic laparotomy

PURPOSE

Sonography provides a fast, portable, and noninvasive method for patient assessment. However, the benefit of providing real-time ultrasound (US) imaging and fluid quantification shortly after patient arrival has not been explored. The objective of this study was to prospectively validate a US hemoperitoneum scoring system developed at our institution and determine whether sonography can predict a therapeutic operation.

METHODS

For 12 months, prospective data on all patients undergoing a trauma sonogram were recorded. All sonograms positive for free fluid were given a hemoperitoneum score. The US score was compared with initial systolic blood pressure and base deficit to assess the ability of sonography to predict a therapeutic laparotomy.

RESULTS

Forty of 46 patients (87%) with a US score > or = 3 required a therapeutic laparotomy. Forty-six of 54 patients with a US score < 3 (85%) did not need operative intervention. The sensitivity of sonography was 83% compared with 28% and 49% for systolic blood pressure and base deficit, respectively, in determining the need for therapeutic operation.

CONCLUSION

We conclude that the majority of patients with a score > or = 3 will need surgery. The US hemoperitoneum scoring system was a better predictor of a therapeutic laparotomy than initial blood pressure and/or base deficit.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSION

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

Surgeon-performed ultrasound imaging in acute surgical disorders

As the role of the general surgeon continues to evolve, the surgeon's use of ultrasound imaging will surely influence practice patterns, particularly for the evaluation of patients in the acute setting. With the use of real-time imaging, the surgeon receives "instantaneous" information to augment the physical examination, to narrow the differential diagnosis, or to initiate an intervention. With select ultrasound examinations, the surgeon can rapidly evaluate adult and pediatric patients with an acute abdomen, especially those patients who are hypotensive. In the hands of the surgeon, this noninvasive, bedside tool can assess more accurately the presence, depth, and extent of an abscess, confirm complete aspiration, or diagnose wound dehiscence before it is apparent on physical examination. Ultrasound imaging is so accurate for the diagnosis of pyloric stenosis that it has essentially replaced the upper gastrointestinal series in most institutions. The surgeon's use of ultrasound imaging to detect a pleural effusion has virtually supplanted the lateral decubitus radiograph. Furthermore, an ultrasound-guided thoracentesis not only facilitates the procedure but improves its safety. As surgeons become more facile with ultrasound imaging, it is anticipated that other uses will develop to further enhance its value for the assessment of patients in the acute setting.

Diagnostic performance of trauma US in identifying abdominal or pelvic free fluid and serious abdominal or pelvic injury

RATIONALE AND OBJECTIVES

This study assessed the ability of a six-point trauma ultrasound (US) evaluation (a) to identify the presence of free fluid in the abdomen or pelvis, with computed tomography (CT) and laparotomy used as diagnostic standards and (b) to predict the presence of abdominal or pelvic injury, particularly injury requiring surgical intervention.

MATERIALS AND METHODS

Of 156 patients who underwent US evaluation for free fluid after sustaining blunt and penetrating trauma, 147 were entered into the prospective study and underwent follow-up CT and/or laparotomy (n = 79), in-hospital observation, or outpatient examination.

RESULTS

The sensitivity, specificity, positive predictive value, negative predictive value, and overall accuracy of US for identifying abdominal or pelvic free fluid were 69%, 100%, 100%, 95%, and 95%, respectively. The corresponding values for predicting abdominal and pelvic injury on the basis of free fluid status alone were 57%, 99%, 80%, 96%, and 95%, respectively. Performing repeated US examinations in patients with deteriorating clinical status decreased the false-negative rate by 50%, increasing the sensitivity for free fluid detection to 85% and the negative predictive value to 97%. Similarly, the sensitivity and negative predictive value for detection of injury increased to 71% and 97%, respectively. A learning curve was also observed, with 67% of the false-negative findings occurring in the first 3 months of the 19-month study.

CONCLUSION

A six-point trauma US evaluation can reliably identify abdominal and pelvic free fluid, which can be a reliable indicator of abdominal or pelvic injury. Scanning conditions must be optimized, and the approach to clinical management must be cautious.

Feasibility and profitability of a radiology department providing trauma US as part of a trauma alert team

RATIONALE AND OBJECTIVES

The purpose of this study was to assess the feasibility and profitability of a radiology department providing a six-point trauma ultrasound (US) examination for abdominal or pelvic free fluid as part of a trauma alert team.

MATERIALS AND METHODS

The study included 191 trauma alerts, which generated 156 US examinations. A radiologist and a departmental technologist carried beepers and responded to level I and II traumas. A departmental secretary or technologist recorded when the responding technologist exited and re-entered the department and if US was performed. If performed, the US examination evaluated the four abdominal and pelvic quadrants and the suprapubic and subxiphoid regions. For 64 patients, the responding technologist recorded the times of the trauma alert, emergency room arrival, US start and finish, and return to the radiology department.

RESULTS

Median response, wait, scan duration, and return times were 2, 8, 5, and 7 minutes, respectively. Median costs for the technician, physician, archiving, transcription, and equipment were $8.17, $30.85, $0.97, $4.80, and $41.22, respectively. Reimbursement per examination averaged $110.60. Sensitivity analyses that varied the time spent (median vs mean), US non-use rate (10%-18%), and years of depreciation (5-7 years) yielded net results ranging from a $36.60 profit to a $6.12 loss per examination.

CONCLUSION

A radiology department can profitably respond to trauma alerts and provide a six-point trauma US examination for free fluid.

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.

Abdominal sonography in examination of children with blunt abdominal trauma

OBJECTIVE

The objective of our study was to evaluate abdominal sonography for the detection of fluid and organ injury in children with blunt abdominal trauma.

SUBJECTS AND METHODS

Fifty-one consecutive children with blunt abdominal trauma requiring abdominal CT were prospectively examined with sonography. Sonograms and CTs were independently evaluated by two radiologists for fluid and organ injury; CT examinations were considered abnormal if either was identified. Differences in CT interpretation were settled by a third observer. Using CT as the truth standard, we calculated the sensitivity, specificity, and negative predictive value of sonography for both observers. Agreement of the sonographic interpretations was evaluated using kappa statistic.

RESULTS

In 33.3% of patients, CT revealed fluid, organ injury, or both. The sensitivity and specificity of sonography when detection of fluid was the sole parameter evaluated was 58.8% and 79.4%, respectively, for observer 1 and 47.1% and 79.4%, respectively, for observer 2. In contrast, the sensitivity and specificity of sonography when detection of both fluid and organ injury was evaluated was 64.7% and 79.4%, respectively, for observer 1 and 70.6% and 70.6%, respectively, for observer 2. The negative predictive value of sonography was 79.4% and 75.0% with evaluation limited to detection of fluid and 81.8% and 82.8% with evaluation of fluid and organ abnormality for observers 1 and 2 , respectively. Agreement was excellent for sonographic identification of fluid (kappa = 0.82) but poor for detection of organ injury (kappa = 0.34).

CONCLUSION

The low sensitivity and negative predictive value of sonography when assessing for either fluid alone or fluid and organ injury suggest that a normal screening sonography alone in the setting of blunt abdominal trauma fails to confidently exclude the presence of an intraabdominal injury.

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.

ED evaluation of the pediatric trauma patient by ultrasonography

The purpose of this study was to determine the accuracy of ultrasound examination of pediatric trauma patients by emergency physicians. Pediatric (age less than 18 years) trauma patients presenting to the emergency department of a level I trauma center were prospectively examined with bedside ultrasound during the secondary survey of their trauma resuscitation. Examinations were performed by emergency medicine residents and attending physicians who had completed an 8-hour course on trauma ultrasonography. Trauma physicians providing care to the patient were blinded to the results of the examination. In 47 children (median age 9 years) computed tomography of the abdomen/pelvis or laparotomy were also performed and served as gold standards to verify the presence or absence of free fluid in the abdomen. Sensitivity, specificity, and accuracy of the ultrasound examination for the detection of free fluid in the abdominal cavity was 75% (95% confidence interval [CI] 36% to 95%), 97% (95% CI 81% to 100%), and 92% (95% Cl 77% to 98%). Positive and negative predictive values were 90% (95% CI 46% to 100%) and 92% (95% CI 74% to 99%), respectively. Ultrasound examinations took an average of 7 minutes and 36 seconds, although this did not take into consideration delays created by interruptions for other diagnostic tests or procedures. An emergency physician and radiologist agreed on blinded interpretations of 83% of the examinations (kappa = 0.56). Bedside ultrasonography is a reliable and rapid method for screening traumatized children for the presence or absence of free fluid in the peritoneum even in the hands of novice sonographers.

Diagnostic evaluation of patients with blunt abdominal trauma: a decision analysis

OBJECTIVES

Using decision analysis, to compare the expected utility (EU) of diagnostic peritoneal lavage (DPL), computed tomography (CT), and ultrasonography (US) to determine the optimal modality for the evaluation of blunt abdominal trauma (BAT) in hemodynamically stable adults.

METHODS

Data points for the decision analysis were obtained from three sources: 1) prevalence of BAT and the sensitivity and specificity of each diagnostic modality were determined through a criteria-based review of the literature; 2) rate of BAT necessitating immediate intervention, perioperative complication rate, and operative mortality rate were calculated using data from the authors' institution's trauma registry; and 3) outcome utilities were determined by telephone survey of adults in a random sample of households in the region. The decision tree was constructed and evaluated in standard fashion. For each diagnostic modality, the authors calculated the EU using the minimum, mean, and maximum sensitivity and specificity across a range of prevalence. Mean outcome utilities were used for each branch of the tree when calculating the EU.

RESULTS

The EU of CT was consistently lower than the EUs of DPL and US at all levels of prevalence. However, the rank order of the EUs of US and DPL varied with the prevalence of BAT. When the prevalence was <30%, the EU of US was higher than that for DPL. When the prevalence was 30-40%, the EUs were similar. When the prevalence was >40%, the EU of US was less than that of DPL.

CONCLUSIONS

Among institutions operating under constraints similar to those used in this model, the optimal diagnostic modality for the evaluation of BAT can be determined based on the sensitivity and specificity of the modality at their institution and the prevalence of BAT in their patient population.

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.

Accuracy of surgeon-performed gallbladder ultrasound

BACKGROUND

Symptomatic cholelithiasis is among the most common of general surgery referrals. With an appropriate clinical presentation, definitive diagnosis requires documentation of gallstones by ultrasonography (US). The authors evaluated the accuracy of surgeon-performed US for identifying gallstones in patients with a nonacute indication for study.

METHODS

Patients referred for symptomatic cholelithiasis and who provided informed consent received an US examination by one or more of the surgical investigators. Surgeon-performed US findings were correlated with radiologist US findings and pathologic diagnoses.

RESULTS

Seventy-seven patients received a total of 128 examinations by the investigators. Surgeon-performed US examination agreed with the radiologist US findings for 112 of 122 studies (92%) with a sensitivity of 100% and a specificity of 95%. Surgeon-performed US findings correlated with the pathologic diagnoses for 83 of 86 studies (97%).

CONCLUSIONS

Surgeons can perform gallbladder US in the nonacute setting with a high degree of accuracy.

New concepts in the management of patients with penetrating abdominal wounds

In the future, trauma research and care will have to become better, faster, and less expensive. Surgeons in the next millennium must be able to diagnose wounds, initiate correct procedures, and anticipate complications more accurately than before. Violent crime will not abate, nor will the proliferation of more powerful arms; these trends translate into graver traumatic wounds, giving the operating team less time to stabilize patients. Time management and team coordination are becoming key elements for patient survival, especially for patients with potentially fatal wounds, such as those to the heart. The authors have reduced the time from arrival to surgery to a few minutes. The keys to this feat are readiness, team coordination, and high morale. Financial resources will continue to be limited and allocated on a need-first basis. In the future, trauma centers will compete for dwindling funds. Technology is and always will be just a tool, whereas qualified trauma surgeons are irreplaceable, much more so than in any other surgical specialty. Observation, diagnosis, and surgery are, of course, greatly facilitated by ever-evolving technology, but since the time of Hippocrates, split-second decisions can ultimately be made only by the caregiver in the white smock. Trauma surgeons in the next millennium will have to exercise judgment based on knowledge, surgical skills, and contact with patients. To err is human, but in surgery, errors often cause death, and no machine will ever relieve surgeons of that burden.

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.

The diagnosis of gastrointestinal tract injuries resulting from blunt trauma

BACKGROUND

This review studies the efficacy of the methods of assessment of the abdomen in blunt trauma for the detection of gastrointestinal tract injuries (GITI).

METHODS

MEDLINE searches of English language publications on the subjects of diagnostic peritoneal lavage, abdominal computed tomography (CT) in blunt trauma and gastrointestinal tract injuries between 1980 and 1998 were used to identify relevant material. Earlier publications were identified from reference lists. The methodology, data and conclusions of all studies were examined in detail. The contemporary roles of clinical assessment, diagnostic peritoneal lavage, CT and other diagnostic modalities in detection of significant GITI were determined based on the best available evidence.

CONCLUSIONS

The most accurate and safest methods of assessment of the abdomen in haemodynamically unstable patients with suspected abdominal injuries following blunt trauma are immediate laparotomy or diagnostic peritoneal lavage (DPL). The goal of assessment of the abdomen in stable patients is to accurately define the site and extent of intra-abdominal injury, in order that further management may be tailored to the specific injuries. The most recent evidence suggests that CT of the abdomen fulfils these criteria better than the other modalities of assessment available. The risk of overlooking a significant GITI on CT scan is minimal provided that unexplained free fluid, bowel wall thickening or enhancement, mesenteric fat streaking and bowel dilatation are taken as evidence of GITI. When scan quality is suboptimal or expert interpretation is unavailable, DPL is recommended. Fully cooperative patients with negligible abdominal signs can be safely observed clinically.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSION

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

Ultrasound of blunt abdominal trauma

Widely accepted in Europe and Asia as a screening tool for blunt abdominal trauma, sonography is gradually gaining popularity among trauma and emergency physicians in the United States. Sonography has been shown to be comparable with DPL and CT for the detection of hemoperitoneum and superior to both modalities because of its rapidity, noninvasiveness, portability, and low cost. With its ability to demonstrate the amount of intraperitoneal hemorrhage within minutes of a patient's arrival, sonography may be considered the screening modality of choice for 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.

Ultrasound: Impact on Diagnostic Peritoneal Lavage, Abdominal Computed Tomography, and Resident Training

Our objective was to determine the impact of abdominal ultrasound (US) on 1) the use of diagnostic peritoneal lavage (DPL) and abdominal computed tomography (ACT) for diagnosing blunt abdominal trauma (BAT) and on 2) surgical resident training. The study design was a retrospective chart review. Patients sustaining BAT who had ACT or DPL done during the 1-year period before the introduction of US (pre-US) were compared with those from a 1-year period beginning 6 months after US (post-US). Data collected included diagnostic modality, demographic data, mortality, associated injuries, length of stay, mechanism of injury, and number of exploratory laparotomies. Of 128 patients in the pre-US group, 35 patients (27%; P < 0.001) underwent DPL, 0 patients (0%; P < 0.001) received US, and 92 patients (72%) received ACT, with positive results for 31 patients (34%). Exploratory laparotomy was performed on 35 patients (27%) in the pre-US group. Of 140 patients in the post-US group, 8 patients (6%; P < 0.001) underwent DPL, 120 patients (85%; P < 0.001) received US, and 108 patients (77%) received ACT, with positive results for 44 patients (42%). Exploratory laparotomy was performed on 22 patients (15%; P < 0.001) in the post-US group. Resident experience with DPL before and after the introduction of US and availability of US for graduated residents was documented. Chi-square and Fisher's exact test were used for statistical analysis. Resident experience changed from 22 to 3 DPLs per year in the pre- and post-US groups, respectively. Ten per cent of graduating residents had US available for use after leaving this institution. US replaced DPL and resulted in slightly more positive ACT scans in assessing BAT at our institution. Paradoxically, only 10 per cent of graduating residents had US available after leaving this institution. Until the use of US for diagnosing BAT has widespread use in the community, we must question our adequacy of resident preparation for diagnosing BAT.

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.

Focused Assessment with Sonography for Trauma (FAST): results from an international consensus conference

OBJECTIVE

To assemble an international panel of experts to develop consensus recommendations on selected important issues on the use of ultrasonography (US) in trauma care.

SETTING

R Adams Cowley Shock Trauma Center, University of Maryland Medical System, Baltimore, Md. The conference was held on December 4, 1997.

PARTICIPANTS

A committee of two co-directors and eight faculty members, in the disciplines of surgery and emergency medicine, representing four nations. Each faculty member had made significant contributions to the current understanding of US in trauma.

RESULTS

Six broad topics felt to be controversial or to have wide variation in practice were discussed using the ad hoc process: (1) US nomenclature and technique; (2) US for organ-specific injury; (3) US scoring systems; (4) the meaning of positive and negative US studies; (5) US credentialing issues; and (6) future applications of US. Consensus recommendations were made when unanimous agreement was reached. Majority viewpoints and minority opinions are presented for unresolved issues.

CONCLUSION

The consensus conference process fostered an international sharing of ideas. Continued communication is needed to advance the science and technology of US in trauma care.

Ultrasound for the detection of intraperitoneal fluid: the role of Trendelenburg positioning

A prospective, observational study was performed to evaluate the role of Trendelenburg positioning in improving the sensitivity of the single-view ultrasound examination. Hemodynamically stable patients undergoing diagnostic peritoneal lavage (DPL) were assigned to one of two groups: supine or 5 degrees of Trendelenburg positioning. Baseline right intercostal oblique images of Morison's pouch were obtained followed by additional images for each 100 cc of lavage fluid instilled into the peritoneal cavity. The initial volume of fluid required to identify an anechoic stripe was recorded for each patient. Patients were excluded if they had (1) a positive DPL for hemoperitoneum (defined as 10 cc of gross blood or >100,000 red blood cells/microL), (2) positive baseline ultrasound study, (3) hemodynamic instability, or (4) lack of documentation (ie, baseline/subsequent hard copy images were not obtained or inadequately demonstrated anechoic stripe). The mean quantity of fluid for visualization of the anechoic stripe was 443.8 cc in the Trendelenburg group (n = 8) and 668.2 cc in the supine group (n = 11). These means were statistically different (P < .05, t test). The median amount of fluid needed for visualization of the anechoic stripe was 400 cc and 700 cc for the Trendelenburg and supine groups, respectively.

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.

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.

Surgeon-performed ultrasound for the assessment of truncal injuries: lessons learned from 1540 patients

OBJECTIVE

To determine the accuracy of the Focused Assessment for the Sonographic examination of the Trauma patient (FAST) when performed by trauma team members during a 3-year period, and to determine the clinical conditions in which the FAST is most accurate in the assessment of injured patients.

SUMMARY BACKGROUND DATA

The FAST is a rapid test that sequentially surveys the pericardial region for hemopericardium and then the right and left upper quadrants and pelvis for hemoperitoneum in patients with potential truncal injuries. The clinical conditions in which the FAST is most accurate in the assessment of injured patients have yet to be determined.

METHODS

FAST examinations were performed on patients with precordial or transthoracic wounds or blunt abdominal trauma. Patients with a positive ultrasound (US) examination for hemopericardium underwent immediate surgery, whereas those with a positive US for hemoperitoneum underwent a computed tomography scan (if they were hemodynamically stable) or immediate celiotomy (if they were hemodynamically unstable- blood pressure < or = 90 mmHg).

RESULTS

FAST examinations were performed in 1540 patients (1227 with blunt injuries, 313 with penetrating injuries). There were 1440 true-negative results, 80 true-positive results, 16 false-negative results, and 4 false-positive results; the sensitivity was 83.3%, the specificity 99.7%. US was most sensitive and specific for the evaluation of patients with precordial or transthoracic wounds (sensitivity 100%, specificity 99.3%) and hypotensive patients with blunt abdominal trauma (sensitivity 100%, specificity 100%).

CONCLUSIONS

US should be the initial diagnostic modality for the evaluation of patients with precordial wounds and blunt truncal injuries because it is rapid and accurate. Because of the high sensitivity and specificity of US in the evaluation of patients with precordial wounds and hypotensive patients with blunt torso trauma, immediate surgical intervention is justified when those patients have a positive US examination.

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.

Surgeon-performed ultrasound: its use in clinical practice

OBJECTIVE

To highlight areas where surgeon-performed ultrasound (US) is an effective diagnostic and therapeutic tool.

SUMMARY BACKGROUND DATA

The success of US in trauma and technologic advances have enhanced the interest and ability of surgeons to perform their own US examinations.

METHODS

General surgeons perform US examinations of the thyroid gland, breast, gastrointestinal tract, peritoneal cavity (laparoscopy), and vascular system. Essentials of these examinations are discussed and a plan for educating surgical residents in US is outlined.

RESULTS

Focused assessment for the sonographic examination of the trauma patient, or FAST, is replacing central venous pressure measurements to detect hemopericardium and diagnostic peritoneal lavage to detect hemoperitoneum. Bedside US can be used to detect a pleural effusion so well in critically ill patients that lateral decubitus x-rays are rarely needed. US-directed biopsy of breast lesions is a common office procedure. Laparoscopic US allows tumor staging without formal celiotomy, and many hepatic and pancreatic surgical procedures include US as an adjunct. Endoscopic and endorectal US have added a new dimension to the assessment of many gastrointestinal lesions. Color flow duplex imaging and endoluminal US have significantly expanded the diagnostic and therapeutic aspects of vascular imaging. The training program developed at Emory University and Grady Memorial Hospital is offered as a model for educating surgical residents in US techniques.

CONCLUSIONS

US is a valuable addition to the general surgeon's diagnostic armamentarium and is rapidly becoming an integral part of the surgeon's clinical practice.

Ultrasound is an effective triage tool to evaluate blunt abdominal trauma in the pediatric population

BACKGROUND

Although computed tomography has been considered the diagnostic modality of choice for pediatric patients with blunt abdominal trauma (BAT), it is costly, time-consuming, requires sedation, and may be associated with complications in young children. Abdominal ultrasonography (US) is a promising modality in the evaluation of BAT that is quick, noninvasive, repeatable, and cost-effective. We hypothesized that emergency department US, performed by trauma surgeons, is a useful triage tool for pediatric BAT that reduces the need for computed tomography.

METHODS

The 230 children (<18 years old) with suspected BAT were initially evaluated with US in the emergency department by surgeons. Subsequent computed tomographic scan or exploratory laparotomy was performed as indicated by the key clinical pathway.

RESULTS

Twelve children (5.2%) had documented intra-abdominal injuries. All five injured children with significant intraperitoneal fluid were identified by US. Of the seven patients who had intra-abdominal injury not detected by US, six sustained solid organ injuries that were managed nonoperatively. Extrapolated reductions in hospital charges due to the decreased number of computed tomographic scans total $130,000.

CONCLUSIONS

Using US as a triage tool may dramatically reduce the cost of pediatric BAT evaluation while being able to quickly identify significant intraperitoneal fluid that requires further evaluation and possible laparotomy.

Usefulness and limitations of ultrasonography in the initial evaluation of blunt abdominal trauma

BACKGROUND

In the assessment of blunt abdominal trauma, the reliability of ultrasonography (US) in identifying individual organ injuries remains uncertain, in spite of its usefulness in detecting hemoperitoneum. This study was designed to evaluate the overall diagnostic value of US, including identification of individual organ injuries.

METHODS

The accuracy of US in the detection of intra-abdominal injuries and the identification of individual organ injuries was evaluated in 1,239 patients seen during a 15-year period. Accuracy was based on detection of intraperitoneal fluid, free air, or irregular parenchymal lesions.

RESULTS

For the detection of injuries, US was 94.6% sensitive, 95.1% specific, and 94.9% accurate. Individual organ injuries were identified with sensitivities of 92.4, 90.0, 92.2, 71.4, and 34.7% for the liver, spleen, kidneys, pancreas, and intestine, respectively.

CONCLUSION

US is reliable for the detection of injuries and the identification of solid-organ injuries despite its poor sensitivity for intestinal injuries.

The surgeon's use of ultrasound in the acute setting

As the role of the general surgeon continues to evolve, the surgeon's use of ultrasound will surely influence practice patterns, particularly for the evaluation of patients in the acute setting. With the use of real-time imaging, the surgeon receives "instantaneous" information to augment the physical examination, narrow the differential diagnosis, or initiate an intervention. With select ultrasound examinations, the surgeon can rapidly evaluate adult and pediatric patients who present with an acute abdomen, especially those in shock. In the hands of the surgeon, this noninvasive bedside tool can more accurately assess the presence, depth, and extent of an abscess, confirm complete aspiration, or diagnose wound dehiscence before it is apparent on physical examination. Ultrasound is so accurate for the diagnosis of pyloric stenosis that it has essentially replaced the upper gastrointestinal series in most institutions. The surgeon's use of ultrasound to detect a pleural effusion has virtually replaced the lateral decubitus film. Furthermore, an ultrasound-guided thoracentesis not only facilitates the procedure but improves its safety. Many ICUs now have protocols in place to perform routine duplex surveillance of those patients who are considered at high risk for the development of thromboembolic complications. As surgeons become more facile with ultrasound, it is anticipated that other uses will develop to further enhance its value for the assessment of patients in the acute setting.

Ultrasound as used in thoracoabdominal trauma

Because it is unique in being portable, rapid, and noninvasive, ultrasound is particularly suited to the trauma setting. When performed by the surgeon, it offers immediate feedback that can be incorporated into the management plan for the patient. Multiple studies in this area have now documented that surgeons can perform and interpret focused ultrasound examinations. Enthusiasm for surgeons as ultrasonographers will likely increase now that the Advanced Trauma Life Support Subcommittee of the American College of Surgeons has published an algorithm that includes ultrasound for the assessment of patients with blunt truncal injuries. As a rapid, sensitive, and specific diagnostic test for the detection of pericardial tamponade, hemothorax, and hemoperitoneum, ultrasound is now an integral part of the practice at many Level I trauma centers.

The history of ultrasound

Diagnostic medical ultrasound may have a brief history, but its roots date back to the early nineteenth century. From its modest beginnings in military institutions where ultrasound was used to examine pathologic specimens, to the routine evaluation of the fetus, injured patients, and those with cerebrovascular disease, ultrasound has secured a position as a key diagnostic test both currently and in the future. Its ability to diagnose valvular and congenital heart disease has reduced the need for invasive cardiac angiography with its attendant risks. Furthermore, endoluminal, transvaginal, transrectal, and transesophageal ultrasound have expanded physicians' diagnostic armamentarium and ability to "look inside" their patients. Notwithstanding all these advancements, ultrasound research and development continue to be fostered, and the ideas of today will be the technology of tomorrow (Fig. 5).

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.

Can surgeons evaluate emergency ultrasound scans for blunt abdominal trauma?

OBJECTIVE

To determine whether surgeons and residents with minimal training can evaluate accurately emergency ultrasound (US) examinations compared with radiologists for blunt abdominal trauma.

METHODS

Over 7 months, we conducted a prospective study comparing the evaluation of emergency US for blunt abdominal trauma by surgeons and attending radiologists. US readings from the surgical team and the radiologists were correlated with outcome.

RESULTS

One hundred-twelve patients were included in the study. Ninety-two patients had an US read as negative by the surgical and radiology services with no subsequent injuries identified. Eighteen patients had an US deemed positive by the surgical service and radiologists. Injuries were confirmed in this group by operation or computed tomography. One patient had an US deemed positive by the surgical team and subsequently negative by the radiologist. A diagnostic peritoneal lavage was performed which was negative. Another patient had an US interpreted as negative by the surgical evaluator and positive by the radiologist. Exploratory laparotomy was negative for intraabdominal hemorrhage or organ injury. Overall results reveal an accuracy on US reading of 99% for the surgical team and 99% for the attending radiologists.

CONCLUSION

Surgeons and surgical residents at different levels of training can accurately interpret emergency ultrasound examinations for blunt trauma from the real-time images, at a level comparable to attending radiologists.

Splenic injury: trends in evaluation and management

BACKGROUND

Changing methods of evaluating blunt abdominal trauma and expanding selection criteria for nonoperative management (NOM) of splenic injury can increase the number of patients managed nonoperatively without affecting success rates.

METHODS

The charts of 164 patients with blunt splenic injuries from July 1, 1991, to June 30, 1996, were reviewed. Thirty-eight patients were excluded because of immediate laparotomy without adjunctive tests or expiration in the resuscitative period. Injuries were graded according to the Organ Injury Scale.

RESULTS

Overall, successful NOM occurred in 84% of patients (73 of 87). NOM was successful in 5 of 7 patients > 55 years old and in 14 of 15 patients with Glasgow Coma Scale scores < 13.

CONCLUSION

Use of computed tomography increased NOM of splenic trauma from 11 to 71% during the 5-year period for injuries of equivalent severity. Age > 55 years or abnormal neurologic status should not preclude NOM, because success was related only to injury grade.

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.

Blunt and penetrating trauma--has anything changed?

Management of abdominal trauma has changed significantly in the last decade. The next decade will also see significant change as imaging and minimally invasive surgical techniques evolve and more approaches are examined in well-designed prospective studies.

Role of ultrasonography in blunt abdominal trauma

Patients with blunt abdominal trauma (BAT) often have equivocal signs of intra-abdominal injury. Diagnostic peritoneal lavage (DPL) has been the 'gold standard' for evaluating these patients, the use of ultrasound (US) being a recent phenomenon. Seventy-three patients with BAT and equivocal physical signs were subjected to both DPL and US for detection of intra-abdominal injury. Based on clinical status, DPL and US findings, the patients underwent laparotomy or non-operative management. DPL was positive in 35 patients. There was one false positive and one false negative result (sensitivity 97.1%, specificity 97.4%, accuracy 97.3%). US was positive in 31 patients. There were 5 false positive and 4 false negative results (sensitivity 86.7%, specificity 88.4%, accuracy 87.7%). Solid viscus injury was documented at laparotomy in 24 patients. DPL failed to detect one pancreatic injury, while US failed to detect 4 splenic and 2 liver injuries. US additionally detected a single case of haemopericardium. Although DPL outperformed US in this study, US can complement DPL in defining the organs injured and in follow up of patients undergoing non-operative management for BAT.

Ultrasonography in blunt abdominal trauma

This article discusses studies of the use of ultrasound in patients with blunt abdominal trauma, both in initial assessment and ongoing evaluation. Reviews of studies of children and adults to detect the presence and extent of hemoperitoneum and organ injuries are presented. Ultrasound results are compared with diagnostic peritoneal lavage, computed tomography, clinical course, and autopsy results. The central question addressed is to what extent can ultrasonography replace or supplement other techniques, particularly diagnostic peritoneal lavage, in the assessment of patients with blunt abdominal trauma. Ultrasound equipment, technique, scoring scales, limitations, and training issues are also addressed.

Ultrasound based key clinical pathway reduces the use of hospital resources for the evaluation of blunt abdominal trauma

BACKGROUND

Evaluating blunt abdominal trauma remains a resource intensive aspect of trauma care. Recently, emergency department ultrasound has been promulgated as a noninvasive diagnostic alternative. Consequently, we hypothesized that an ultrasound based key clinical pathway (KCP) would reduce the number of diagnostic peritoneal lavage (DPL) and computed tomographic (CT) scans required to evaluate blunt abdominal trauma without increased risk to the patient.

METHODS

This study was a prospective analysis of patients evaluated for blunt abdominal trauma during a 3-month period using this KCP compared with a 3-month historical cohort.

RESULTS

Data were collected for 486 KCP patients and were compared with 516 patients in the study cohort. No differences were noted regarding demographics, number of laparotomies, or type of injuries. Using the KCP, DPL was reduced from 17 to 4%, and computed tomography from 56 to 26%. Furthermore, the injury severity score increased from 11.6 to 21.5 for DPL patients and from 4.6 to 8.3 for computed tomography patients. Ultrasound exams were used exclusively in 65% of patients.

CONCLUSIONS

An ultrasound based KCP resulted in significant reductions in the use of invasive DPL and costly CT scanning in the evaluation of blunt abdominal trauma without risk to the patient.