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

Evaluation of focussed assessment with sonography in trauma (FAST) by UK emergency physicians

OBJECTIVES

To evaluate the introduction of a focussed assessment with sonography in trauma (FAST) scan into the early assessment of trauma patients in the UK.

METHODS

The setting was an inner city teaching hospital emergency department (annual attendance 100,000). All patients aged 16 or over admitted to the resuscitation room after blunt trauma were included in a prospective observational study. Patients had a FAST scan performed at the end of the primary survey. Results were compared to results of other investigations, laparotomy, postmortem examination, or observation.

RESULTS

153 patients were entered into the study. The sensitivity of the FAST scan was 78% and specificity was 99%.

CONCLUSION

FAST is a highly specific "rule in" technique and is useful in the initial assessment of trauma patients. Emergency physicians can perform FAST after a brief training period.

Evaluation of a 15-year experience with splenic injuries in a state trauma system

BACKGROUND

The management of splenic injuries has evolved with a greater emphasis on nonoperative management. Although several institutions have demonstrated that nonoperative management of splenic injuries can be performed with an increasing degree of success, the impact of this treatment shift on outcome for all patients with splenic injuries remains unknown. We hypothesized that outcomes for patients with splenic injuries have improved as the paradigm for splenic injury treatment has shifted.

METHODS

Consecutive patients from 1987 to 2001 with splenic injuries who were entered into a state trauma registry were reviewed. Demographic variables, injury characteristics, and outcome data were collected.

RESULTS

The number of patients who were diagnosed with splenic injuries increased from 1987 through 2001, despite a stable number of institutions submitting data to the registry. The number of minor injuries and severe splenic injuries remained stable, and the number of moderately severe injuries significantly increased over time. Overall mortality rate improved but primarily reflected the decreased mortality rates of moderately severe injuries; the mortality rate for severe splenic injuries was unchanged.

CONCLUSION

Trauma centers are seeing increasing numbers of splenic injuries that are less severe in magnitude, although the number of the most severe splenic injuries is stable. The increased proportion of patients with less severe splenic injuries who are being admitted to trauma centers is a significant factor in the increased use and success rate of nonoperative management.

Portable ultrasound in pre-hospital emergencies: a feasibility study

BACKGROUND

Ultrasound plays a central role in the evaluation of both trauma and medical emergencies. The development of portable sonography devices could extent its application into the pre-hospital arena. The aim of our study was to evaluate feasibility of pre-hospital ultrasound in the Norwegian Air Rescue setting.

MATERIAL AND METHODS

During a 3-month period, we conducted a prospective study using sonography in pre-hospital patient management. All examinations were carried out by the same ultrasound-certified physician using a Primedic Handyscan in a standardized focused protocol for abdominal and lung sonography and a subcostal 2-chamber long axis view. Inclusion criteria were abdominal/thoracic and obstetric trauma, circulatory/respiratory compromise, pulseless electric activity (PEA) in cardiac arrest, acute abdomen and monitoring during transport. Allowed examination time was restricted to 3 min on the scene. The patient's gender, age, symptoms, trauma mechanism, quality of visualization and diagnose made were recorded. Pre-hospital results were compared with in-hospital findings.

RESULTS

Thirty-eight patients were entered into the study. Three patients had to be excluded due to technical difficulties. Nineteen medical, 15 traumas and 1 obstetric patient were included. Good visualization was obtained in 74% (n= 26), moderate in 26% (n = 9). Median examination time was 2.5 min (range 1-3 min). Nine patients (26%) showed positive sonography findings. Sensitivity was 90%, specificity 96%. Diagnostic usefulness was high in undetermined cardiac arrest and hypotension and massive hematoperitoneum.

CONCLUSION

Pre-hospital ultrasound when applied by an proficient examiner using a goal-directed, time sensitive protocol is feasible, does not delay patient management and provides diagnostic and therapeutic benefit. Further studies are warranted to identify the exact indications and role of pre-hospital sonography.

An evaluation of the American College of Surgeons’ ultrasound education program

BACKGROUND

Ultrasound has a wide variety of applications in surgery, but until recently few surgeons received any formal training in its use. To facilitate incorporation of ultrasound into surgical practice, the American College of Surgeons (ACoS) developed an ultrasound educational program. The purpose of this study was to evaluate the impact and effectiveness of the ACoS ultrasound education program.

METHODS

A survey was mailed to all surgeons who had completed at least one of several ultrasound courses offered by the ACoS from 1998 to 2002.

RESULTS

A total of 1,791 surveys were mailed out and 873 completed surveys were returned. Sixty-five percent (576) of respondents reported using ultrasound in their practices after these educational courses. Of those performing ultrasound examinations, 267 did so in one clinical area and 309 in more than one. The most common examination was breast (369 surgeons); vascular, acute/trauma, abdominal, intraoperative/laparoscopic, and head/neck were utilized fairly equally (100-200 surgeons). The number of examinations performed by surgeons before they felt competent was between 11 and 20 and did not vary by the type of ultrasound examination. Of the 267 surgeons performing ultrasound in one clinical area, 176 performed ultrasound-guided procedures. Most surgeons had access to 2 ultrasound machines, but 386 (67%) were restricted from performing ultrasound in certain locations.

CONCLUSIONS

The ACoS ultrasound courses are extremely popular and have contributed to the increasing use of ultrasound in surgical practice. Surgeons successfully use ultrasound in their practices including performance of ultrasound-guided procedures but are restricted from using ultrasound in certain patient care areas. Since many surgeons received prior and/or additional training outside of the ACoS, there is a need to facilitate export of ACoS courses to other venues and to focus on incorporating ultrasound training into surgical residency programs.

Prehospital ultrasound imaging improves management of abdominal trauma

BACKGROUND

Blunt abdominal trauma with intra-abdominal bleeding is often underdiagnosed or even overlooked at trauma scenes. The purpose of this prospective, multicentre study was to compare the accuracy of physical examination and prehospital focused abdominal sonography for trauma (PFAST) to detect abdominal bleeding.

METHODS

Six rescue centres took part in the study from December 2002 to December 2003, including 230 patients with suspected abdominal injury. The accuracy of physical examination at the scene and PFAST were compared. Later examinations in the emergency department (ultrasonography and/or computed tomography) were used as the reference standard.

RESULTS

The complete protocol and follow-up was obtained in 202 patients. The sensitivity, specificity and accuracy of PFAST were 93 per cent, 99 per cent and 99 per cent, respectively, compared with 93 per cent, 52 per cent and 57 per cent for physical examination at the scene. Scanning with PFAST occurred a mean(s.d.) 35(13) min earlier than ultrasound in the emergency department. Abdominal bleeding was detected in 14 per cent of patients. Using PFAST led to a change in either prehospital therapy or management in 30 per cent of patients, and a change to admitting hospital in 22 per cent.

CONCLUSION

In this study, PFAST was a useful and reliable diagnostic tool when used as part of surgical triage at the trauma scene.

Surgeon-Performed Bedside Organ Assessment With Sonography After Trauma (BOAST): A Pilot Study From the WTA Multicenter Group

BACKGROUND

Although nonoperative management of solid organ injuries is a well-accepted practice, a rapid method to assess the progression of the injury, the early development of organ-related complications, and the frequency with which follow-up computed tomography (CT) scans are needed has yet to be determined. The use of ultrasound in this setting may provide information that would improve the rate of organ salvage and decrease the patient's morbidity. The objectives of this study were to determine whether surgeons could successfully use a bedside organ assessment with sonography after trauma (BOAST) examination to: (1) detect a solid organ injury; and (2) assess for changes in the size of the organ injury, an increase or decrease in hemoperitoneum, and the development of organ-related complications.

METHODS

A prospective, multicenter study was conducted using BOAST to evaluate patients undergoing nonoperative management of their solid organ injuries. Patients had to have: (1) a Focused Assessment for Sonography of Trauma (FAST) examination on admission; (2) a solid organ injury documented by an admission abdominal CT scan; and (3) the criteria for nonoperative management. BOAST was performed within 24 hours of admission and every 3 to 4 days to evaluate for an increase or decrease in hemoperitoneum [Ultrasound (US) heme score: from 0 = none to 3 = large], change in injury size, and organ-specific complications. BOAST results were compared with the radiologists' interpretation of the initial and follow-up CT scans, and with patient outcomes.

RESULTS

During a 22 month period, 126 patients sustained 135 solid organ injuries, 46 (34.1%) of these were seen by BOAST (Error rate = 66%). Serial US heme scores = 0 (no hemoperitoneum) were observed in 56 of 126 patients who had a combination of multi-system injury and a dropping Hgb, indicating that there was no further bleeding from the injured organ(s). Surgeons detected 13 of the 15 complications that were confirmed later by conventional imaging.

CONCLUSIONS

(1) BOAST has limitations in identifying solid organ injuries, especially those that are lower grade; (2) the US heme score is a valuable adjunct to the clinical examination in following patients with high-grade solid organ injuries and a dropping hemoglobin; and (3) although uncommon, organ-related complications may be identified using BOAST.

Ocular examination for trauma; clinical ultrasound aboard the International Space Station

BACKGROUND

Ultrasound imaging is a successful modality in a broad variety of diagnostic applications including trauma. Ultrasound has been shown to be accurate when performed by non-radiologist physicians; recent reports have suggested that non-physicians can perform limited ultrasound examinations. A multipurpose ultrasound system is installed on the International Space Station (ISS) as a component of the Human Research Facility (HRF). This report documents the first ocular ultrasound examination conducted in space, which demonstrated the capability to assess physiologic alterations or pathology including trauma during long-duration space flight.

METHODS

An ISS crewmember with minimal sonography training was remotely guided by an imaging expert from Mission Control Center (MCC) through a comprehensive ultrasound examination of the eye. A multipurpose ultrasound imager was used in conjunction with a space-to-ground video downlink and two-way audio. Reference cards with topological reference points, hardware controls, and target images were used to facilitate the examination. Multiple views of the eye structures were obtained through a closed eyelid. Pupillary response to light was demonstrated by modifying the light exposure of the contralateral eye.

RESULTS

A crewmember on the ISS was able to complete a comprehensive ocular examination using B- and M-mode ultrasonography with remote guidance from an expert in the MCC. Multiple anteroposterior, oblique, and coronal views of the eye clearly demonstrated the anatomic structures of both segments of the globe. The iris and pupil were readily visualized with probe manipulation. Pupillary diameter was assessed in real time in B- and M-mode displays. The anatomic detail and fidelity of ultrasound video were excellent and could be used to answer a variety of clinical and space physiologic questions.

CONCLUSIONS

A comprehensive, high-quality ultrasound examination of the eye was performed with a multipurpose imager aboard the ISS by a non-expert operator using remote guidance. Ocular ultrasound images were of diagnostic quality despite the 2-second communication latency and the unconventional setting of a weightless spacecraft environment. The remote guidance techniques developed to facilitate this successful NASA research experiment will support wider applications of ultrasound for remote medicine on Earth including the assessment of pupillary reactions in patients with severe craniofacial trauma and swelling.

Prospective analysis of the effect of physician experience with the FAST examination in reducing the use of CT scans

OBJECTIVE

The objective of this study was to examine the effect of ultrasound experience level on emergency physicians' Focused Assessment with Sonography for Trauma (FAST) exam accuracy and emergency physicians' confidence in using FAST findings to assist in managing patients with blunt trauma.

METHODS

This prospective, consecutive enrolment study evaluated adult trauma team activation blunt trauma patients. Based on the number of post-training FAST exams carried out, 11 attending emergency physicians were grouped into A (<25 exams, n = 4), B (26-50 exams, n = 4) or C (>50 exams, n = 3). The FAST exam was carried out prior to other diagnostic studies. The emergency physicians were asked to prospectively judge their perception of the need for surgery, abdominal CT or no further tests. All study patients ultimately underwent CT, diagnostic peritoneal lavage or laparotomy. Among each physician group, the number of subsequent CT scans deemed necessary by the emergency physician after a 'normal' FAST was calculated and compared.

RESULTS

Accuracy was greatest in group C. Sixty-nine of 80 patients in group A had a normal FAST exam; emergency physicians deemed CT necessary in 68/69 cases (99%; confidence interval [CI] 92-100%). Eighty-two of 98 patients in group C had a normal FAST exam; emergency physicians deemed CT necessary in 19/82 cases (23%; CI 15-34%). Physicians in groups B and C were less likely to order CT after a normal FAST than group A (P < 0.001).

CONCLUSIONS

FAST accuracy was greatest among more experienced emergency physicians. A normal FAST exam assisted more experienced emergency physicians with the perceived need to order significantly fewer CT scans than less experienced emergency physicians.

FAST at MACH 20: clinical ultrasound aboard the International Space Station

BACKGROUND

Focused assessment with sonography for trauma (FAST) examination has been proved accurate for diagnosing trauma when performed by nonradiologist physicians. Recent reports have suggested that nonphysicians also may be able to perform the FAST examination reliably. A multipurpose ultrasound system is installed on the International Space Station as a component of the Human Research Facility. Nonphysician crew members aboard the International Space Station receive modest training in hardware operation, sonographic techniques, and remotely guided scanning. This report documents the first FAST examination conducted in space, as part of the sustained effort to maintain the highest possible level of available medical care during long-duration space flight.

METHODS

An International Space Station crew member with minimal sonography training was remotely guided through a FAST examination by an ultrasound imaging expert from Mission Control Center using private real-time two-way audio and a private space-to-ground video downlink (7.5 frames/second). There was a 2-second satellite delay for both video and audio. To facilitate the real-time telemedical ultrasound examination, identical reference cards showing topologic reference points and hardware controls were available to both the crew member and the ground-based expert.

RESULTS

A FAST examination, including four standard abdominal windows, was completed in approximately 5.5 minutes. Following commands from the Mission Control Center-based expert, the crew member acquired all target images without difficulty. The anatomic content and fidelity of the ultrasound video were excellent and would allow clinical decision making.

CONCLUSIONS

It is possible to conduct a remotely guided FAST examination with excellent clinical results and speed, even with a significantly reduced video frame rate and a 2-second communication latency. A wider application of trauma ultrasound applications for remote medicine on earth appears to be possible and warranted.

Rare right ventricular myxoma detected incidentally on a FAST examination

A young man underwent Focused Assessment with Sonography in Trauma (FAST) scan for blunt abdominal trauma. An incidental finding on the pericardial view was the presence of a tumor in the right ventricle. Detailed cardiac imaging and subsequent excision revealed the presence of a myxoma. The patient had no obvious cardiac symptoms, but the awareness and experience of the examiner during the FAST examination detected this rare heart tumor at a latent stage, preventing serious, irreversible complications. This case demonstrates the potential importance of looking above the diaphragm during routine abdominal sonography, especially in patients who are critically ill.

Blunt Abdominal Trauma:Does the Use of a Second-Generation Sonographic Contrast Agent Help to Detect Solid Organ Injuries?

OBJECTIVE

The objective of our study was to prospectively evaluate whether a second-generation sonography contrast agent (SonoVue) can improve the conspicuity of solid organ injuries (liver; spleen; or kidney, including adrenal glands) in patients with blunt abdominal trauma.

SUBJECTS AND METHODS

Two hundred ten consecutive hemodynamically stable trauma patients underwent both abdominal sonography and CT at admission. The presence of solid organ injuries and the quality of sonography examinations were recorded. Patients with false-negative sonography findings for solid organ injuries in comparison with CT results underwent control sonography. If a solid organ injury was still undetectable, contrast-enhanced sonography was performed. Findings of admission, control, and contrast-enhanced sonograms were compared with CT results for their ability to depict solid organ injuries. Contrast-enhanced sonography was also performed in patients in whom a vascular injury (pseudoaneurysm) was shown on admission or control CT.

RESULTS

CT findings were positive for 88 solid organ injuries in 71 (34%) of the 210 patients. Admission, control, and contrast-enhanced sonograms had a detection rate for solid organ injury of 40% (35/88), 57% (50/88), and 80% (70/88), respectively. The improvement in the detection rate between control and contrast-enhanced sonography was statistically significant (p = 0.001). After exclusion of low-quality examinations, contrast-enhanced sonography still missed 18% of solid organ injuries. Five vascular liver (n = 1) and spleen (n = 4) injuries (pseudoaneurysms) were detected on CT; all were visible on contrast-enhanced sonography.

CONCLUSION

Contrast-enhanced sonography misses a large percentage of solid organ injuries and cannot be recommended to replace CT in the triage of hemodynamically stable trauma patients. However, contrast-enhanced sonography could play a role in the detection of pseudoaneurysms.

Evaluation of a focused assessment with sonography for trauma protocol to detect free abdominal fluid in dogs involved in motor vehicle accidents

OBJECTIVE

To establish a focused assessment with sonography for trauma (FAST) protocol in dogs, determine whether FAST can be performed by veterinary clinicians without extensive ultrasonographic experience, and assess the frequency of free fluid (as determined via FAST) in the abdominal cavity of dogs following motor vehicle accidents (MVAs).

DESIGN

Prospective study.

ANIMALS

100 client-owned dogs evaluated within 24 hours of an MVA.

PROCEDURE

Dogs were placed in lateral recumbency for the FAST examination. To detect fluid in the abdomen, 2 ultrasonographic views (transverse and longitudinal) were obtained at each of 4 sites (just caudal to the xiphoid process, on the midline over the urinary bladder, and at the left and right flank regions).

RESULTS

In the 100 dogs evaluated via FAST, free abdominal fluid was detected in 45 dogs. In 40 of those 45 dogs, abdominocentesis was performed; hemoperitoneum and uroperitoneum were diagnosed in 38 and 2 dogs, respectively. Compared with dogs that had no free abdominal fluid detected via FAST, dogs that had free abdominal fluid detected via FAST had significantly higher heart rates and serum lactate concentrations and significantly lower PCVs and total solid concentrations.

CONCLUSIONS AND CLINICAL RELEVANCE

Results indicate that FAST is a simple and rapid technique that can be performed on dogs in an emergency setting to detect intra-abdominal free fluid and can be performed by veterinary clinicians with minimal previous ultrasonographic experience.

Minimum training for right upper quadrant ultrasonography

The objective of this study was to assess if 10 right upper quadrant (RUQ) ultrasound (US) examinations could be used as a minimum standard for training. This was a retrospective review of patients with suspected gallbladder pathology who underwent resident-performed RUQ US before operative or department of radiology evaluation. Two hundred twenty-four patients were examined using resident-performed RUQ US followed by gold standard evaluations. One hundred seventy-eight patients were evaluated by 13 residents who met the "minimum training" standard of 10 prior examinations. The results of resident-performed RUQ US for gallstones and/or cholecystitis are shown subsequently. Previous suggestions that 10 examinations could be used as a minimum standard for training in focused abdominal sonography for trauma examinations cannot be used for RUQ US. The ACEP 2001 guidelines for 25 examinations are more consistent with the learning curve suggested by our data.

Ultrasound in abdominal trauma

This article reviews current issues regarding the Focused Assessment with Sonography for Trauma (FAST) examination. Technical performance issues, decision-making and practice algorithms, fluid volume and scoring systems, proficiency and training, and the role of the FAST in pediatric trauma are covered. This article examines the FAST examination from a practical, evidenced-based stand-point.

Residents should not independently perform focused abdominal sonography for trauma after 10 training examinations

OBJECTIVES

To assess whether 10 focused abdominal sonography for trauma (FAST) examinations could be used as a minimum standard for training, as suggested previously.

METHODS

This was a retrospective review of patients with abdominal trauma who underwent resident-performed FAST examinations before surgical or Department of Radiology evaluation.

RESULTS

Six hundred ninety-eight patients were examined by resident-performed FAST followed by reference standard evaluations. Four hundred twelve patients were evaluated by residents who previously performed 10 FAST examinations; 154 were evaluated by 29 residents performing their 11th through 30th examinations; and 258 were evaluated by 10 residents performing their 31st and subsequent examinations. The results of resident-performed FAST for intraperitoneal free fluid were as follows: 11 to 20 examinations--sensitivity, 73.9% (95% confidence interval, 51.3%-88.9%); specificity, 98.8% (92.5%-99.9%); true-positive findings, 17; true-negative, 81; false-positive, 1; false-negative, 6; total patients, 105; 21 to 30 examinations--sensitivity, 100% (73.2%-100%); specificity, 97.1% (83.3%-99.9%); true-positive, 14; true-negative, 34; false-positive, 1; false-negative, 0; total patients, 49; 31 and more examinations--sensitivity, 94.8% (88.6%-97.9%); specificity, 98.6% (94.5%-99.8%); true-positive, 110; true-negative, 140; false-positive, 2; false-negative, 6; total patients, 258.

CONCLUSIONS

The suggestion that 10 examinations could be used as a minimum standard for training in FAST examinations was not validated.

The Ultrasound Screen for Penetrating Truncal Trauma

A prospective blinded pilot study was performed at an urban level 1 trauma center to evaluate the efficacy of ultrasound in ruling out penetrating visceral truncal injury. For 8 months, 49 nonconsecutive patients who presented with truncal gunshot and stab wounds were evaluated by a 10-MHz ultrasound tranducer probe. The deepest muscle bundle and the fascia enveloping it was examined by ultrasound. These images were compared to the equivalent contralateral unaffected side of the patient. All the patients then underwent standard testing to evaluate for potential intracavitary injury. Forty-nine patients with a mean age of 28 years (SD, 8.8) were evaluated by ultrasound. A total of 58 injuries were evaluated of which 37 were stab wounds and 21 were gunshot wounds. Thoracoabdominal and back and flank injuries were the most commonly evaluated injuries. There were 20 true positives, 20 false positives, and 18 true negatives, each with approximately twice as many stab as gunshot wounds. There were no false negatives. The sensitivity and negative predictive value of ultrasound in determining clinically significant truncal visceral injury in penetrating truncal trauma is 100 per cent. The specificity and positive predictive value are both approximately 50 per cent. Ultrasonic examination of the injured abdominal wall layers in truncal penetrating trauma is an excellent screening tool. Simple comparative assessment with the unaffected contralateral side allows a highly sensitive method of decreasing the number of potentially morbid, time consuming, and expensive tests that are currently employed to rule out visceral injury.

Performance, training, quality assurance, and reimbursement of emergency physician-performed ultrasonography at academic medical centers

OBJECTIVE

To determine the current state of bedside emergency physician-performed ultrasonography in terms of prevalence, training, quality assurance, and reimbursement at emergency medicine residency programs.

METHODS

The link to a 10-question Web-based survey was e-mailed to ultrasound/residency directors at 122 emergency medicine residency programs in the United States.

RESULTS

The overall response rate was 84%. Ninety-two percent of programs reported 24-hour emergency physician-performed ultrasonography availability. Fifty-one percent of programs reported that a credentialing/privileging plan was in place at their hospital, and 71% of programs had a quality assurance/image review procedure in place. Emergency medicine specialty-specific guidelines of 150 ultrasonographic examinations and 40 hours of didactic instruction were met by 39% and 22% of residencies, respectively, although only 13.7% of programs were completing the 300 examinations recommended by the American Institute of Ultrasound in Medicine. Sixteen programs (16%) reported that they were currently billing for emergency physician-performed ultrasonography; of those not billing, 10 (12%) planned to bill within 1 year, and 32 (37%) planned to bill at some point in the future.

CONCLUSIONS

Performance and training in emergency physician-performed ultrasonography at academic medical centers continues to increase. The number of emergency medicine residency programs meeting specialty-specific guidelines has more than doubled in the last 4 years, but only a small number are meeting American Institute of Ultrasound in Medicine guidelines. Although only 16% of programs reported that they were currently billing for emergency physician-performed ultrasonography, most had plans to bill in the future.

Establishment of a teaching animal model for sonographic diagnosis of trauma

BACKGROUND

Ultrasound is widely accepted as a valuable diagnostic tool for detecting intra-abdominal and intrathoracic bleeding in trauma patients. Nevertheless, many doctors are reluctant to use it because they do not have sufficient training. This study aimed to define intra-abdominal and intrathoracic fluid volumes that can be detected by sonography and their relation to fluid width in pigs to establish a clinically relevant animal model for teaching and training.

METHODS

Different volumes of normal saline were infused into the abdomen (50-2,000 mL) and chest (25-250 mL) in five anesthetized pigs. The maximum width of fluid as detected by ultrasound was recorded. The right upper quadrant, left upper quadrant, pelvis, and right paracolic section of the abdomen and right pleural cavity were studied. An experienced radiologist performed the studies. The effects on respiratory and cardiovascular functions were evaluated.

RESULTS

The sonographic findings in the pig were similar to those in humans. Up to 50 mL of intra-abdominal fluid and up to 25 mL of intrathoracic fluid could be detected by ultrasound. There was a significant correlation between the volume infused and the fluid width detected. The respiratory and cardiovascular monitoring of the animals showed that the infused intrathoracic volumes mimicked a survivable hemothorax.

CONCLUSION

The pig may serve as an excellent clinically relevant model with which to teach surgeons detection of different volumes of intra-abdominal and intrathoracic fluids. The value of this model as an educational tool has yet to be tested.

Surgeon-Directed Ultrasound for Trauma is a Predictor of Intra-Abdominal Injury in Children

This study investigated the efficacy of surgeon-directed focused assessment with sonography for trauma (FAST) in conjunction with physical exam (PEx) as a predictor of intra-abdominal injury in children. Injured children (ages ≤17) presenting to a level I trauma center with abdominal trauma were evaluated in the emergency department (ED) by the trauma team of surgical attendings and residents. PEx and FAST were performed immediately upon arrival to the ED and results compared to CT, the standard exam for presence of intra-abdominal injury. Data was collected prospectively from July 1, 2000, until April 30, 2002. One hundred and twenty injured children underwent evaluation of abdominal trauma with PEx, FAST, and abdominal CT. Two patients had false-negative CT scans. Bayesian analysis was applied to the results of the remaining 118 patients. FAST compared with CT findings revealed sensitivity 70 per cent, specificity 100 per cent, positive predictive value 100 per cent, and negative predictive value 92 per cent. FAST results were combined with PEx findings such that either suggestive of intra-abdominal injury was regarded as a “positive exam.” Sensitivity was 100 per cent, specificity 74 per cent, positive predictive value 53 per cent, and negative predictive value 100 per cent. Surgeon-directed FAST with consideration of PEx is a predictor of intra-abdominal injury in children.

Successful diagnosis of penetrating cardiac injury using surgeon-performed sonography

BACKGROUND

Patients with penetrating cardiac injuries have a high mortality. The utilization of sonography in these patients may lead to earlier diagnosis and definitive surgical intervention.

METHODS

A retrospective review of all patients admitted to a level I trauma center were examined from March 1996 to March 2001 (17,241 patients). Patients were identified with penetrating thoracic injuries and were evaluated for mechanism of injury, sonographic findings (subxiphoid and parasternal windows), injury severity score, length of stay, and mortality. Surgeons performed all sonography.

RESULTS

There were 478 patients who underwent sonography for penetrating thoracic injuries. Twenty-three patients were identified with positive sonographic findings. Subsequently 20 patients had a cardiac injury at surgery. There were no missed injuries. The 3 patients with false positive findings had congestive heart failure (2 patients) and morbid obesity (1 patient). Mean time to operation was 13 minutes. Mean injury severity score was 33. Mean intensive care unit and hospital stay was 3.1 days and 7.2 days respectively. Sonography had a specificity of 99.3% and sensitivity of 100% for identifying penetrating cardiac injury and a positive predictive value of 87% and negative predictive value of 100%. There were no hospital deaths.

CONCLUSIONS

Early diagnosis and management using surgeon performed sonography may reduce the high mortality associated with penetrating cardiac injury.

Sensitivity in detecting free intraperitoneal fluid with the pelvic views of the FAST exam

The multiple-view focused assessment with sonography for trauma (FAST) exam is an integral tool in the assessment of blunt abdominal trauma. A prospective observational study was performed to compute the average minimum volume of detectable intraperitoneal fluid with the pelvic views of the FAST exam. All adult patients from October 1999 to May 2001, who presented to the ED with blunt abdominal trauma and underwent a clinically indicated diagnostic peritoneal lavage (DPL), were candidates for admission to the pelvic ultrasound study. In the supine position, patients were administered lavage fluid in 100 cc increments until the examiner detected the fluid on ultrasound. An independent reviewer also examined the hard-copy ultrasound images for fluid detection. 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/mL), (2) a positive initial ultrasound for free fluid, or (3) lacked sufficient hard-copy ultrasound images. The mean minimal volume of fluid needed for pelvic ultrasound detection by the examiner and reviewer was 157 and 129 cc (n = 7), respectively. The median quantity of fluid for ultrasound detection by both the examiner and reviewer was 100 cc. The pelvic views of the FAST exam identified a significantly smaller quantity of intraperitoneal fluid than previous studies of the right upper quadrant single-view exam.

Wireless and satellite transmission of prehospital focused abdominal sonography for trauma

OBJECTIVE

As military operations become smaller and more remote and as humanitarian missions increase, ultrasound technology is emerging as a valuable asset for defining injuries in austere settings. This study evaluated the feasibility of focused abdominal sonography for trauma (FAST) examinations in a field environment with real-time images sent wireless to an antenna and over satellite.

METHODS

Using a 6-lb SonoSite portable ultrasound device with battery pack, FAST examinations were performed on a healthy volunteer, transferred wireless at distances of 1,000 and 1,500 feet from the receiving antenna using a vest-mounted microwave transmitter, and then redirected over satellite (INMARSAT) to a remote hospital for review by emergency physicians, and a radiologist.

RESULTS

Real-time wireless transmissions at 1,500 feet reliably yielded images without quality or interpretability drop compared with those recorded digitally at the examination site. A 32% reduction in image quality and interpretability was seen with still images and a 42% reduction was noted with cine loops using INMARSAT. The authors did not find the upper distance limit of the wireless transmitter used.

CONCLUSION

This study suggests 1) that remote FAST examinations are plausible for prehospital care and triage using new-generation portable ultrasound units, 2) that line-of-sight transmission of FAST examinations when compared with on-site images results in no degradation in image quality or interpretability at distances used, 3) that ranges greater than 1,500 feet are feasible for interpretable examinations and therefore line-of-site mass casualty or field triage sites, and 4) that real-time INMARSAT transmission of FAST examinations at 64 kbps may serve a limited role for remote clinical interpretation.

Unusual case of acute onset abdominal pain: uses and limitations of medical imaging

A 28-year-old male with atraumatic abdominal pain and transient hypotension was assessed using bedside emergency department (ED) ultrasonography and contrast enhanced helical computed tomography (CT). Both tests revealed free intraperitoneal fluid, but neither detected a splenic defect. The patient subsequently underwent splenectomy for a ruptured spleen. His serology for typical viral causes was negative. This article discusses spontaneous splenic rupture, the role of imaging in diagnosis, and the limitations of ED ultrasound and contrast enhanced helical CT.

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.

Predicting the need for laparotomy in pediatric trauma patients on the basis of the ultrasound score

BACKGROUND

It is possible to quantify the amount of hemoperitoneum seen on focused assessment with sonography for trauma (FAST) using a simple scoring system that had previously been shown to correlate with the need for subsequent laparotomy in adults. A score of 3 or greater was shown to be highly accurate in predicting the need for laparotomy. We hypothesized that this scoring system might also predict the need for laparotomy in pediatric trauma patients.

METHODS

We retrospectively reviewed all records for patients 15 years and younger who underwent FAST after blunt trauma. A "positive" ultrasound examination was defined as one containing free intraperitoneal fluid with or without solid organ injury. The ultrasound score (USS) was defined as the depth of the deepest pocket of fluid collection measured in centimeters plus the number of additional spaces where fluid was seen.

RESULTS

Thirty-eight (19.6%) of 193 patients who had FAST performed had positive ultrasound examinations. Thirty-seven patients with complete records were analyzed. There were no differences between patients with a USS < or = 3.0 and those with a USS > 3.0 in terms of admission pulse, Glasgow Coma Scale score, Injury Severity Score, or the proportion of patients who were initially hypotensive. One of 22 patients with a USS < or = 3.0 required therapeutic laparotomy versus 8 of 15 patients with a USS > 3.0 ( = 0.002). For a USS > 3.0, sensitivity, specificity, and accuracy in predicting therapeutic laparotomy were 89%, 75%, and 78%, respectively.

CONCLUSION

Ultrasound quantification of hemoperitoneum by a simple scoring system may serve as a useful adjunct to traditional clinical parameters in predicting the need for subsequent laparotomy in pediatric patients. Prospective validation with a larger study is required.

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.

Emergency ultrasound credentialling for focused assessment sonography in trauma and abdominal aortic aneurysm: A practical approach for Australasia

OBJECTIVE

Focused assessment with sonography for trauma and emergency ultrasound for abdominal aortic aneurysm are now practiced widely by non-radiologists in emergency departments worldwide. Various credentialling programs have been proposed for novice sonographers; however, their feasibility has been questioned. We adopted the Australasian College for Emergency Medicine (ACEM) credentialling process for emergency ultrasound to determine whether it is feasible for emergency physicians in the Australasian environment.

METHODS

Three full-time emergency medicine specialists and a post-Fellowship Examination trainee at Auckland Hospital undertook the credentialling process.

RESULTS

All four participants had sufficient scans to complete the process after 16 months. Accuracy for focused assessment with sonography for trauma, 90% (95% CI 83-95%), and abdominal aortic aneurysm, 99% (95% CI 90-100%), is similar to that previously reported.

CONCLUSION

The ACEM credentialling process for focused assessment with sonography for trauma and abdominal aortic aneurysm is practical and achievable for emergency medicine specialists working in the Emergency Department at Auckland Hospital. Further studies are necessary to determine whether this holds true for other major trauma centres in Australasia.

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.

Do we really need routine computed tomographic scanning in the primary evaluation of blunt chest trauma in patients with "normal" chest radiograph?

BACKGROUND

A major cause of morbidity and mortality after blunt chest trauma remains undetected injuries. This study evaluates the role of routine computed tomographic (CT) scan.

METHODS

We studied 93 consecutive patients from January 1999 to July 2000: 73 (76.3%) after motor vehicle crash with crash speed > 10 mph, and 22 (23.7%) after fall from height > 5 ft. Simultaneous with initial clinical evaluation, anteroposterior chest radiograph and helical chest CT scan were obtained for all patients.

RESULTS

Sixty-eight patients (73.1%) showed at least one pathologic sign on chest radiograph, and 25 patients (26.9%) had normal chest radiograph. In 13 (52.0%) of these 25 patients, the CT scan showed multiple injuries; among these were two aortic lacerations, three pleural effusions, and one pericardial effusion.

CONCLUSION

Over 50% of patients with normal initial chest radiograph showed multiple injuries on the CT scan, among which were also two (8%) potentially fatal aortic lesions. We therefore recommend primary routine chest CT scan in all patients with major chest trauma.

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.

Systematic review and meta-analysis of emergency ultrasonography for blunt abdominal trauma

BACKGROUND

How precise and reliable is ultrasonography as a primary tool for injury assessment in blunt abdominal trauma?

METHODS

A systematic review and meta-analysis were conducted of prospective clinical trials of ultrasonography for blunt abdominal trauma. Publications were retrieved by structured searching among databases, review articles and major text books. Authors and experts in the field were contacted for original and unpublished data. For statistical analysis, summary receiver operating characteristic curves (SROCs) were computed using weighted and robust regression models, with Q* denoting the shoulder of the curve. Post-test probabilities were calculated as a function of pooled likelihood ratios (LRs).

RESULTS

Thirty of 123 trials enrolling 9047 patients were eligible for final analysis. With respect to targeting organ lesions, ultrasonography showed a summary Q* value of 0.91 (inverse variance weights, 95 per cent confidence interval (c.i.) 0.76-1.07); negative predictive values ranged from 0.72 to 0.99. A similar SROC slope was calculated for screening for free fluid (Q* = 0.89 (95 per cent c.i. 0.73-1.05)). Ultrasonography detects the presence of organ lesions, but fails to exclude abdominal injuries (random effects negative LR 0.23 (95 per cent c.i. 0.18-0.28)). Given a pretest probability of 50 per cent for blunt abdominal injury, a post-test probability of nearly 25 per cent remains in the case of a negative sonogram.

CONCLUSION

Despite its high specificity, ultrasonography has an unexpectedly low sensitivity for the detection of both free fluid and organ lesions. In clinically suspected abdominal trauma, another assessment (e.g. helical computed tomography) must be performed regardless of the initial ultrasonographic findings.

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.

Impact of recent trends of noninvasive trauma evaluation and nonoperative management in surgical resident education

BACKGROUND

The use of ultrasonography and nonoperative management of solid organ injury has become standard practice in many trauma centers. Little is known about the effects of these changes on resident educational experience.

METHODS

We retrospectively reviewed resident evaluation of abdominal trauma and trauma operative experience as reported to the residency review committee between 1994 and 1999.

RESULTS

A total of 4,052 patients underwent one or more of three diagnostic modalities. The nontherapeutic laparotomy rate as a result of positive diagnostic peritoneal lavages decreased from 35% to 14%. Although resident operative trauma experience was stable because of increases in operative burns and nonabdominal trauma, the number of abdominal procedures declined.

CONCLUSION

Noninvasive diagnostic tests have allowed more rapid trauma evaluation and fewer nontherapeutic laparotomies. As nonoperative experience grows, the opportunity for operative experience decreases. These trends may adversely affect the education of residents and suggest that novel approaches are needed to ensure adequate operative experience in trauma.

Defining the Learning Curve for the Focused Abdominal Sonogram for Trauma (FAST) Examination: Implications for Credentialing

Focused Abdominal Sonogram for Trauma (FAST) examination is being used increasingly for the torso evaluation of injured patients. In a controlled setting using peritoneal dialysis patients as models for injured patients with free fluid we hypothesized that more experienced providers would perform FAST with greater accuracy. Twelve fellow or attending level trauma surgeons, two radiologists, and one ultrasound technician were studied for their ability to detect intraperitoneal fluid (0–1600 cm3) in nine peritoneal dialysis patients with two different volumes of dialysate/patient. FAST experience with injured patients was defined as minimal (<30 patients examinations), moderate (30–100), or extensive (>100). All surgeons had participated in a didactic/practical course before the study. Test results were reported as “+” or “-” by the participant; “+” results were further quantified by volume. The sensitivity of those in the minimal-, moderate-, and extensive-experience to detect <1 L was 45, 87, and 100 per cent, respectively; the accuracy in detecting dialysate volume within 250 cm3 was 38, 63, and 90 per cent, respectively. In this controlled setting the accuracy of FAST particularly in diagnosing smaller volumes, as well as the ability to quantify volume, improves with experience. The learning curve for FAST starts to flatten out at 30 to 100 examinations. Training and credentialing policies should consider these findings to optimize patient care.

Surgeon-performed ultrasound in the critical care setting: its use as an extension of the physical examination to detect pleural effusion

BACKGROUND

Critically ill surgical patients are often difficult to assess for complications because of their altered sensorium, multiple monitoring devices, and immobility. Surgeon-performed ultrasound may enhance the physical examination of these patients and provide for an early detection of select complications. We hypothesized that a focused thoracic ultrasound examination could reliably detect a pleural effusion and the results could be used in the decision matrix for patient care.

METHODS

Serial focused thoracic ultrasound examinations were performed by a surgeon and a medical student on critically ill patients. The medical student learned select facets of the physical examination and then demonstrated how ultrasound imaging could enhance these findings. Ultrasound images were recorded on hard copy and videotape, with the results available to the surgical intensive care unit and surgery teams. The images were reviewed and compared with the chest radiograph readings.

RESULTS

Forty-seven patients underwent 140 ultrasound examinations. There were 85 true-negative, 46 true-positive, 9 false-negative, and zero false-positive examination results, yielding an 83.6% sensitivity, 100% specificity, and 94% accuracy. Of the 46 true-positive results, thoracentesis was performed or a thoracostomy tube was placed in 5 patients. Nine false-negative ultrasound examinations occurred in six patients, five of whom had their effusions detected on computed tomographic scans.

CONCLUSION

A focused thoracic ultrasound examination reliably detects pleural effusions in critically ill patients, and the results can be used successfully in the decision matrix for patient care.

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.

Improving continuing medical education for surgical techniques: applying the lessons learned in the first decade of minimal access surgery

OBJECTIVE

To examine the first decade of experience with minimal access surgery, with particular attention to issues of training surgeons already in practice, and to provide a set of recommendations to improve technical training for surgeons in practice.

SUMMARY BACKGROUND DATA

Concerns about the adequacy of training in new techniques for practicing surgeons began almost immediately after the introduction of laparoscopic cholecystectomy. The concern was restated throughout the following decade with seemingly little progress in addressing it.

METHODS

A preliminary search of the medical literature revealed no systematic review of continuing medical education for technical skills. The search was broadened to include educational, medical, and psychological databases in four general areas: surgical training curricula, continuing medical education, learning curve, and general motor skills theory.

RESULTS

The introduction and the evolution of minimal access surgery have helped to focus attention on technical skills training. The experience in the first decade has provided evidence that surgical skills training shares many characteristics with general motor skills training, thus suggesting several ways of improving continuing medical education in technical skills.

CONCLUSIONS

The educational effectiveness of the short-course type of continuing medical education currently offered for training in new surgical techniques should be established, or this type of training should be abandoned. At present, short courses offer a means of introducing technical innovation, and so recommendations for improving the educational effectiveness of the short-course format are offered. These recommendations are followed by suggestions for research.