Are diagnostic peritoneal lavage or focused abdominal sonography for trauma safe screening investigations for hemodynamically stable patients after blunt abdominal trauma? A review of the literature

Diagnostic Peritoneal Aspiration or Lavage in Stratified Groups of Hypotensive Blunt Trauma Patients

BACKGROUND

Some reports suggest Diagnostic peritoneal aspiration (DPA) or lavage (DPL) may better select which hypotensive blunt trauma patients (BTPs) require operation, compared to ultrasonography. However, whether both moderately hypotensive (systolic blood pressure [SBP] < 90 mmHg) and severely hypotensive (SBP < 70 mmHg) patients benefit from DPA/DPL is unclear. We hypothesized DPA/DPL used within the first hour increases risk of death for severely vs moderately hypotensive BTPs.

METHODS

The 2017-2019 Trauma Quality Improvement Program database was queried for BTPs ≥ 18 years old with hypotension upon arrival. We compared moderately and severely hypotensive groups. A multivariable logistic regression analysis was performed controlling for age, comorbidities, emergent operation, blood transfusions, and injury profile.

RESULTS

From 134 hypotensive patients undergoing DPA/DPL, 66 (49.3%) had severe hypotension. Patients in both groups underwent an emergent operation (43.9% vs 58.8%, P = .09) in a similar amount of time (median, 42-min vs 54-min, P = .11). Compared to the moderately hypotensive group, severely hypotensive patients had a higher rate and associated risk of death (84.8% vs 50.0%, P < .001) (OR 5.40, CI 2.07-14.11, P < .001). The strongest independent risk factor for death was age ≥ 65 (OR 24.81, CI 4.06-151.62, P < .001).

DISCUSSION

Among all BTPs undergoing DPA/DPL within the first hour of arrival, an over 5-fold increased risk of death for patients with severe hypotension was demonstrated. As such, DPA/DPL within this group should be used with caution, particularly for older patients, as they may be better served by immediate surgeries. Future prospective research is needed to confirm these findings and elucidate the ideal DPA/DPL population in the modern era of ultrasonography.

The Predictive Value of Repeated Abdominal Ultrasonography in Patients with Multiple Trauma and Decreased Level of Consciousness: The Experience of a Resource-Limited Centre

OBJECTIVE

To determine the predictive value of repeated abdominal ultrasonography in patients with multiple trauma and decreased level of consciousness (LOC).

METHODS

This prospective cross-sectional study was conducted over a six-month period at Shahid Rajaee Trauma Hospital, Shiraz, Iran. We included hemodynamically stable blunt abdominal trauma patients with a decreased LOC (Glasgow Coma Scale ≤ 13) who were referred to the neurosurgery ICU ward. Included cases underwent 1 contrast-enhanced CT scan and two-time ultrasonographic study of the abdomen with an interval of 48 hours. The diagnostic accuracy of the ultrasonography was determined according to the CT-scan results.

RESULTS

Overall 80 patients with mean age of 37.75 ± 18.67 years were included. There were 17 (21.3%) women and 63 (78.8%) men among the patients. Compared with the CT-Scan, the first ultrasonography showed a sensitivity of 60%, specificity of 80%, PPV of 16.60%, NPV of 96.80%, and a diagnostic accuracy of 70%. The same values for the second ultrasonographic study were 80%, 79%, 20%, 98%, and 79%, respectively. In 4 (5%) patients whose first ultrasonography and CT scan results were negative, the second ultrasonography was positive for injury.

CONCLUSION

In patients with blunt trauma to the abdomen, when the only indication of abdominal CT scan is a decreased LOC, two ultrasonographic studies can replace a CT imaging.

Predictive value of focused assessment with sonography for trauma (FAST) for laparotomy in unstable polytrauma Egyptians patients

PURPOSE

The emergency physicians face significant clinical uncertainty when multiple trauma patients arrive in the emergency department (ED). The priorities for assessment and treatment of polytrauma patients are established in the primary survey. Focused assessment with sonography for trauma (FAST) is very essential clinical skill during trauma resuscitation. Use of point of care ultrasound among the trauma team working in the primary survey in emergency care settings is lacking in Suez Canal University Hospitals even ultrasound machine not available in ED. This study aims to evaluate the accuracy of FAST in hemodynamically unstable polytraumatized patients and to determine its role as an indication of laparotomy.

METHODS

This study is a cross-sectional study included 150 polytrauma patients with a blunt mechanism admitted in Suez Canal University Hospital. Firstly primary survey by airway check, cervical spine securing with neck collar, maintenance of breathing/circulation and management of life threading conditions if present were conducted accordingly to ATLS (advanced trauma life support) guidelines. The patients were assessed in the primary survey using the FAST as a tool to determine the presence of intra-abdominal collection.

RESULTS

A total of 150 patients, and FAST scans were performed in all cases. The sensitivity and specificity were 92.6% and 100%, respectively. The negative predictive value was 92%, while the positive predictive value of FAST was 100%. The accuracy of FAST was 96%.

CONCLUSION

FAST is an important method to detect intra-abdominal fluid in the initial assessment in hemodynamically unstable polytrauma patients with high accuracy.

Should we perform a FAST exam in haemodynamically stable patients presenting after blunt abdominal injury: a retrospective cohort study

Background

Focussed Assessment with Sonography for Trauma (FAST) is a bedside ultrasonography technique used to detect free intraperitoneal fluid in patients presenting with blunt abdominal trauma (BAT) in the emergency department.

Methods

In this retrospective cohort study we investigated the potential of FAST as a risk stratification instrument in haemodynamically (HD) stable patients presenting after BAT by establishing the association between the FAST exam result and final outcome. An adverse outcome was defined in this context as the need for either a laparoscopy/laparotomy or an angiographic embolization or death due to abdominal injuries).

Results

A total of 421 patients with BAT were included, of which nine had an adverse outcome (2%). FAST was negative in 407 patients. Six of them turned out to have free intraperitoneal fluid (sensitivity 67 [41–86]%). FAST was positive in 14 patients, 12 of whom had free intraperitoneal fluid (specificity 99 [98–100]%). A positive FAST (positive likelihood ratio 34.3 [15.1–78.5]) was stronger associated with an adverse outcome than Injury Severity Score (ISS) or any individual clinical- or biochemical variables measured at presentation in the ED.

Discussion

The FAST exam can provide valuable prognostic information at minimal expenses during the early stages of resuscitation in haemodynamically stable patients presenting with BAT.

Conclusions

FAST exam should not be omitted in patients with BAT.

Electronic supplementary material

The online version of this article (doi:10.1186/s13049-016-0342-0) contains supplementary material, which is available to authorized users.

Sports Ultrasound: Applications Beyond the Musculoskeletal System

BACKGROUND

Traditionally, ultrasound has been used to evaluate musculoskeletal injuries in athletes; however, ultrasound applications extend well beyond musculoskeletal conditions, many of which are pertinent to athletes.

EVIDENCE ACQUISITION

Articles were identified in PubMed using the search terms ultrasound, echocardiogram, preparticipation physical examination, glycogen, focused assessment with sonography of trauma, optic nerve, and vocal cord dysfunction. No date restrictions were placed on the literature search.

STUDY DESIGN

Clinical review.

LEVEL OF EVIDENCE

Level 4.

RESULTS

Several potential applications of nonmusculoskeletal ultrasound in sports medicine are presented, including extended Focused Assessment with Sonography for Trauma (eFAST), limited echocardiographic screening during preparticipation physical examinations, assessment of muscle glycogen stores, optic nerve sheath diameter measurements in athletes with increased intracranial pressure, and assessment of vocal cord dysfunction in athletes.

CONCLUSION

Ultrasound can potentially be used to assist athletes with monitoring their muscle glycogen stores and the diagnosis of multiple nonmusculoskeletal conditions within sports medicine.

Emergency ultrasound-based algorithms for diagnosing blunt abdominal trauma

BACKGROUND

Ultrasonography (performed by means of a four-quadrant, focused assessment of sonography for trauma (FAST)) is regarded as a key instrument for the initial assessment of patients with suspected blunt abdominal and thoraco-abdominal trauma in the emergency department setting. FAST has a high specificity but low sensitivity in detecting and excluding visceral injuries. Proponents of FAST argue that ultrasound-based clinical pathways enhance the speed of primary trauma assessment, reduce the number of unnecessary multi-detector computed tomography (MDCT) scans, and enable quicker triage to surgical and non-surgical care. Given the proven accuracy, increasing availability of, and indication for, MDCT among patients with blunt abdominal and multiple injuries, we aimed to compile the best available evidence of the use of FAST-based assessment compared with other primary trauma assessment protocols.

OBJECTIVES

To assess the effects of diagnostic algorithms using ultrasonography including in FAST examinations in the emergency department in relation to the early, late, and overall mortality of patients with suspected blunt abdominal trauma.

SEARCH METHODS

The most recent search was run on 30th June 2015. We searched the Cochrane Injuries Group Specialised Register, The Cochrane Library, MEDLINE (OvidSP), EMBASE (OvidSP), ISI Web of Science (SCI-EXPANDED, SSCI, CPCI-S, and CPSI-SSH), clinical trials registers, and screened reference lists. Trial authors were contacted for further information and individual patient data.

SELECTION CRITERIA

We included randomised controlled trials (RCTs). Participants were patients with blunt torso, abdominal, or multiple trauma undergoing diagnostic investigations for abdominal organ injury. The intervention was diagnostic algorithms comprising emergency ultrasonography (US). The control was diagnostic algorithms without US examinations (for example, primary computed tomography (CT) or diagnostic peritoneal lavage (DPL)). Outcomes were mortality, use of CT or invasive procedures (DPL, laparoscopy, laparotomy), and cost-effectiveness.

DATA COLLECTION AND ANALYSIS

Two authors (DS and CG) independently selected trials for inclusion, assessed methodological quality, and extracted data. Methodological quality was assessed using the Cochrane Collaboration risk of bias tool. Where possible, data were pooled and relative risks (RRs), risk differences (RDs), and weighted mean differences, each with 95% confidence intervals (CIs), were calculated by fixed-effect or random-effects models as appropriate.

MAIN RESULTS

We identified four studies meeting our inclusion criteria. Overall, trials were of poor to moderate methodological quality. Few trial authors responded to our written inquiries seeking to resolve controversial issues and to obtain individual patient data. Strong heterogeneity amongst the trials prompted discussion between the review authors as to whether the data should or should not be pooled; we decided in favour of a quantitative synthesis to provide a rough impression about the effect sizes achievable with US-based triage algorithms. We pooled mortality data from three trials involving 1254 patients; the RR in favour of the FAST arm was 1.00 (95% CI 0.50 to 2.00). FAST-based pathways reduced the number of CT scans (random-effects model RD -0.52, 95% CI -0.83 to -0.21), but the meaning of this result was unclear.

AUTHORS' CONCLUSIONS

The experimental evidence justifying FAST-based clinical pathways in diagnosing patients with suspected abdominal or multiple blunt trauma remains poor. Because of strong heterogeneity between the trial results, the quantitative information provided by this review may only be used in an exploratory fashion. It is unlikely that FAST will ever be investigated by means of a confirmatory, large-scale RCT in the future. Thus, this Cochrane Review may be regarded as a review which provides the best available evidence for clinical practice guidelines and management recommendations. It can only be concluded from the few head-to-head studies that negative US scans are likely to reduce the incidence of MDCT scans which, given the low sensitivity of FAST (or reliability of negative results), may adversely affect the diagnostic yield of the trauma survey. At best, US has no negative impact on mortality or morbidity. Assuming that major blunt abdominal or multiple trauma is associated with 15% mortality and a CT-based diagnostic work-up is considered the current standard of care, 874, 3495, or 21,838 patients are needed per intervention group to demonstrate non-inferiority of FAST to CT-based algorithms with non-inferiority margins of 5%, 2.5%, and 1%, power of 90%, and a type-I error alpha of 5%.

Diagnostic accuracy of secondary ultrasound exam in blunt abdominal trauma

Background:

In stable patients with blunt abdominal trauma, accurate diagnosis of visceral injuries is crucial.

Objectives:

To determine whether repeating ultrasound exam will increase the sensitivity of focused abdominal sonography for trauma (FAST) through revealing additional free intraperitoneal fluid in patients with blunt abdominal trauma.

Patients and Methods:

We performed a prospective observational study by performing primary and secondary ultrasound exams in blunt abdominal trauma patients. All ultrasound exams were performed by four radiology residents who had the experience of more than 400 FAST exams. Five routine intraperitoneal spaces as well as the interloop space were examined by ultrasound in order to find free fluid. All patients who expired or were transferred to the operating room before the second exam were excluded from the study. All positive ultrasound results were compared with intra-operative and computed tomography (CT) findings and/or the clinical status of the patients.

Results:

Primary ultrasound was performed in 372 patients; 61 of them did not undergo secondary ultrasound exam; thus, were excluded from the study.Three hundred eleven patients underwent both primary and secondary ultrasound exams. One hundred and two of all patients were evaluated by contrast enhanced CT scan and 31 underwent laparotomy. The sensitivity of ultrasound exam in detecting intraperitoneal fluid significantly increased from 70.7% for the primary exam to 92.7% for the secondary exam. Examining the interloop space significantly improved the sensitivity of ultrasonography in both primary (from 36.6% to 70.7%) and secondary (from 65.9% to 92.7%) exams.

Conclusions:

Performing a secondary ultrasound exam in stable blunt abdominal trauma patients and adding interloop space scan to the routine FAST exam significantly increases the sensitivity of ultrasound in detecting intraperitoneal free fluid.

Intra-abdominal injury following blunt trauma becomes clinically apparent within 9 hours

BACKGROUND

The diagnosis of blunt abdominal trauma can be challenging and resource intensive. Observation with serial clinical assessments plays a major role in the evaluation of these patients, but the time required for intra-abdominal injury to become clinically apparent is unknown. The purpose of this study was to determine the amount of time required for an intra-abdominal injury to become clinically apparent after blunt abdominal trauma via physical examination or commonly followed clinical values.

METHODS

A retrospective review of patients who sustained blunt trauma resulting in intra-abdominal injury between June 2010 and June 2012 at a Level 1 academic trauma center was performed. Patient demographics, injuries, and the amount of time from emergency department admission to sign or symptom development and subsequent diagnosis were recorded. All diagnoses were made by computed tomography or at the time of surgery. Patient transfers from other hospitals were excluded.

RESULTS

Of 3,574 blunt trauma patients admitted to the hospital, 285 (8%) experienced intra-abdominal injuries. The mean (SD) age was 36 (17) years, the majority were male (194 patients, 68%) and the mean (SD) Injury Severity Score (ISS) was 21 (14). The mean (SD) time from admission to diagnosis via computed tomography or surgery was 74 (55) minutes. Eighty patients (28%) required either surgery (78 patients, 17%) or radiographic embolization (2 patients, 0.7%) for their injury. All patients who required intervention demonstrated a sign or symptom of their intra-abdominal injury within 60 minutes of arrival, although two patients were intervened upon in a delayed fashion. All patients with a blunt intra-abdominal injury manifested a clinical sign or symptom of their intra-abdominal injury, resulting in their diagnosis within 8 hours 25 minutes of arrival to the hospital.

CONCLUSION

All diagnosed intra-abdominal injuries from blunt trauma manifested clinical signs or symptoms that could prompt imaging or intervention, leading to their diagnosis within 8 hours 25 minutes of arrival to the hospital. All patients who required an intervention for their injury manifested a sign or symptom of their injury within 60 minutes of arrival.

LEVEL OF EVIDENCE

Therapeutic study, level IV. Epidemiologic study, level III.

The role of laparoscopy in abdominal trauma - review of the literature

The necessity of urgent explorative laparotomy as a standard procedure in the treatment of abdominal penetrating wounds is controversial. Mandatory surgical intervention for penetrating abdominal trauma yields a high rate of negative laparotomies in the absence of visceral injuries. Laparoscopy is an alternative diagnostic procedure inspecting the peritoneum for signs of perforation and excluding significant intra-abdominal injuries. Following current guidelines, diagnostic laparoscopy should be used with caution only in selected cases due to the limited amount of reliable data confirming the effectiveness of such treatment. We present a review of the literature analysing the role of diagnostic laparoscopy in abdominal trauma.

Seatbelt injury causing small bowel devascularisation: case series and review of the literature

The use of seatbelts has increased significantly in the last twenty years, leading to a decrease in mortality from road traffic accidents (RTA). However, this increase in seatbelt use has also led to a change in the spectrum of injuries from RTA; abdominal injuries, particularly intestinal injuries have dramatically increased with the routine use of seatbelts. Such intestinal injuries frequently result from improper placement of the “lap belt”. We present 3 cases in which passengers wearing a seatbelt sustained significant devascularisation injuries to the small bowel requiring emergency surgical intervention. A high index of suspicion is crucial in such cases to prevent delays in diagnosis that can lead to severe complications and adverse outcomes. It is evident that while advocating seatbelt use, the importance of education in correct seatbelt placement should also be a focus of public health strategies to reduce RTA morbidity and mortality.

Is the FAST exam reliable in severely injured patients?

INTRODUCTION

Highly sensitive and accurate for the detection of injuries requiring intervention in haemodynamically unstable patients, FAST may underestimate intra-abdominal injuries in stable patients with blunt abdominal trauma. Diminished accuracy of ultrasound has been reported in different cohorts of multiple injured patients. We hypothesised that multiple injured patients with a high Injury Severity Score (ISS) will have a decreased accuracy of FAST for the assessment of blunt abdominal trauma.

METHODS

Data from the trauma registry of a Level 1 trauma centre were retrospectively reviewed. All haemodynamically stable blunt trauma patients who underwent both FAST and CT scan of abdomen from January 1, 2000 to January 1, 2005 were included in the cohort. All patients were divided into three groups according to their ISS: Group 1 included patients with an ISS from 1 to 14, Group 2 included patients with an ISS from 16 to 24, and Group 3 consisted of patients with ISS>or=25.

RESULTS

3181 patients with blunt abdominal trauma included into the study were divided into the three groups according to the ISS. The mean ISS was 7.9+/-3.97, 19.6+/-2.48 and 41.3+/-11.95 in Groups 1, 2 and 3, respectively. The accuracy of ultrasound was 90.6% in the group of patients with the highest ISS (>or=25) compared with 97.5 and 97.1 for Groups 1 and 2 (p<0.001). Similarly, ultrasound had a significantly lower sensitivity, specificity, PPV and NPV for patients in Group 3 compared with the first two groups (p<0.001). There was a significantly lower sensitivity in Group 2 compared with Group 1 (p<0.001), but no differences in specificity, accuracy, PPV or NPV were demonstrated.

CONCLUSION

Patients with high ISS are at increased risk of having ultrasound-occult injuries and have a lower accuracy of their ultrasound examination than patients with low and moderate ISS.

Pitfalls in the evaluation and resuscitation of the trauma patient

The management of the trauma patient presents the practitioner with a host of challenges, and the pace, variety of venues, and multidisciplinary nature of the field combine to create a system complexity that is laden with potential pitfalls. This review summarizes some of the general principles of medical errors and examines some of the more common pitfalls encountered in the initial resuscitation and evaluation of the major trauma patient.

The value of focused assessment with sonography in trauma examination for the need for operative intervention in blunt torso trauma: a rebuttal to “emergency ultrasound-based algorithms for diagnosing blunt abdominal trauma (review)”, from the Cochrane Collaboration

Background and significance

The Cochrane Database of Systematic Reviews published a manuscript critical of the use of the FAST examination. The reference is Stengel D. Bauwens K. Sehouli J. Rademacher G. Mutze S. Ekkernkamp A. Porzsolt F. Emergency ultrasound-based algorithms for diagnosing blunt abdominal trauma. Cochrane Database of Systematic Reviews. (2):CD004446, 2005. UI: 15846717. The stated objective was the assessment of the “efficiency and effectiveness” of ultrasound-inclusive evaluative algorithms in patients with suspected blunt abdominal trauma (BAT). The primary outcome measures explored were Mortality, CT and DPL use, and laparotomy rates. Little or no benefit was seen and the conclusion was that “there is insufficient evidence from randomized controlled trials to justify promotion” of FAST in patients with BAT. While the review used the same rigorous methods employed in all Cochrane Reviews, it appears that several serious flaws plagued the manuscript. The finest methodological rigor cannot yield usable results, if it is not applied to a clinically relevant question. In a world of increasingly conservative management of BAT, do we need FAST, a rapid, repeatable screening modality at the point-of-care to visualize any amount of free fluid or any degree of organ injury? The obvious answer is no. However, quantifying the value of FAST to predict the need for immediate operative intervention (OR) is essential.

Methods

To rebut this recurrent review, a systematic literature review was conducted using verbatim methodologies as described in the Cochrane Review with the exception of telephone contacts. Data were tabulated and presented descriptively.

Results

Out of 487 citations, 163 articles were fully screened, 11 contained prospectively derived data with FAST results, patient disposition and final diagnoses, and a description of cases considered false negatives or false positives. Of the 2,755 patients, 448 (16%) went to the OR. There were a total of 5 patients with legitimately false-negative diagnoses made based on the FAST: 3 involving inadequate scans and 2 of blunt trauma-induced small bowel perforations without hemoperitoneum.

Conclusion

The FAST examination, adequately completed, is a nearly perfect test for predicting a “Need for OR” in patients with blunt torso trauma.

Findings and limitations of focused ultrasound as a possible screening test in stable adult patients with blunt abdominal trauma: a Greek study

Our objective is to underline the place of FAST (focus assessment by sonography for trauma) ultrasonography (US) in the investigation of blunt abdominal trauma. We retrospectively examined the ultrasound findings in 1,999 haemodynamically stable adult patients. These people were admitted to the emergency room (ER) for possible blunt abdominal trauma. All were stable at admission and a FAST ultrasound examination was made. Initial findings were compared with the clinical course after at least 24 h of observation time and CT results. Among the 1,999 US examinations, abnormalities were found in 109 (5.5%) cases. Among them, 102 had free peritoneal fluid, and in 58 examinations, ruptures, lacerations or haematomas were demonstrated. Despite its limitations, such as in cases involving uncooperative patients, excessive bowel gas, obesity and empty bladder, the FAST technique seems to be an accurate method to evaluate the possibility of abdominal blunt trauma in stable patients. Because of the high negative predictive value of the FAST technique in stable patients with blunt abdominal trauma, we recommend that a stable patient with negative ultrasound results at admission remain under close observation for at least 12 or preferably 24 h before being discharged.

Clinical prediction rules for identifying adults at very low risk for intra-abdominal injuries after blunt trauma

STUDY OBJECTIVE

We derive and validate clinical prediction rules to identify adult patients at very low risk for intra-abdominal injuries after blunt torso trauma.

METHODS

We prospectively enrolled adult patients (>or=18 years old) after blunt torso trauma for whom diagnostic testing for intra-abdominal injury was performed. In the derivation phase, we used binary recursive partitioning to create a rule to identify patients with intra-abdominal injury who were undergoing acute intervention (including therapeutic laparotomy or angiographic embolization) and a separate rule for identifying patients with any intra-abdominal injury present. We considered only clinical variables readily available with acceptable interrater reliability. The prediction rules were then prospectively validated in a separate cohort of patients.

RESULTS

In the derivation phase, we enrolled 3,435 patients, including 311 (9.1%; 95% confidence interval [CI] 8.1% to 10.1%) with intra-abdominal injury and 109 (35.0%; 95% CI 29.7% to 40.6%) with intra-abdominal injury requiring acute intervention. In the validation study, we enrolled 1,595 patients, including 143 (9.0%; 95% CI 7.6% to 10.5%) with intra-abdominal injury. The derived rule for patients with intra-abdominal injuries who were undergoing acute intervention consisted of hypotension, Glasgow Coma Scale (GCS) score less than 14, costal margin tenderness, abdominal tenderness, hematuria level greater than or equal to 25 red blood cells/high powered field, and hematocrit level less than 30% and identified all 44 patients in the validation phase with intra-abdominal injury who were undergoing acute intervention (sensitivity 44/44, 100%; 95% CI 93.4% to 100%). The derived rule for the presence of any intra-abdominal injury consisted of GCS score less than 14, costal margin tenderness, abdominal tenderness, femur fracture, hematuria level greater than or equal to 25 red blood cells/high powered field, hematocrit level less than 30%, and abnormal chest radiograph result (pneumothorax or rib fracture). In the validation phase, the rule for any intra-abdominal injury present had the following test performance: sensitivity 137 of 143 (95.8%; 95% CI 91.1% to 98.4%), specificity 434 of 1,452 (29.9%; 95% CI 27.5% to 32.3%), and negative predictive value 434 of 440 (98.6%; 95% CI 97.1% to 99.5%).

CONCLUSION

These derived and validated clinical prediction rules can aid physicians in the evaluation of adult patients after blunt torso trauma. Patients without any of these variables are at very low risk for having intra-abdominal injury, particularly intra-abdominal injury requiring acute intervention, and are unlikely to benefit from abdominal computed tomography scanning.

[The value of sonography in traumatology and orthopedics : Part 2: emergency diagnostics in blunt abdominal and thoracic trauma]

Ultrasound examinations in trauma patients should be done in the emergency department using curved-array (3.5-7.5 MHz) probes. Blunt trauma of the abdomen and thorax must be regarded as a single organ injury. Sonography is the imaging technique of first choice and has completely replaced peritoneal lavage. Paramount advantages are its ability to provide rapid information and reproducible results at short intervals and in a noninvasive manner. The sensitivity and specificity of sonography in detecting intraabdominal fluid are 97-100% and 80-90%, respectively. To achieve such good results, though, adequate education in ultrasound and state-of-the-art devices is crucial. Clinical experiences prove that standardized sonography must be part of polytrauma management and should be integrated in advanced trauma life support courses. Technical improvements with better image quality and miniaturization of hardware will contribute to increase the use of this technique. However, ultrasound does not replace computed tomography for follow-up in answering more sophisticated questions in multiple injured patients.

Focused abdominal sonography for trauma in the emergency department for blunt abdominal trauma

BACKGROUND

Blunt abdominal trauma (BAT) is a diagnostic challenge to the emergency physician (EP). The introduction of bedside ultrasound provides another diagnostic tool for the EP to detect intra-abdominal injuries.

AIMS

To evaluate the performance of EP in a local emergency department in Hong Kong to perform the 'focused abdominal sonography for trauma' (FAST) in BAT patients.

METHODS

This was a retrospective cohort study including all the trauma team cases in a 36-month period in the emergency department of a public hospital in Hong Kong. The results of FAST scans were analyzed and compared with CT scans when the FAST was positive or followed by a period of clinical observation when the FAST was negative. Descriptive statistics and sensitivity, specificity, and predictive values were calculated.

RESULTS

There was a total of 273 cases, and FAST scans were performed in 242 cases. The sensitivity and specificity were 86% and 99%, respectively. The negative predictive value was 0.98, while the positive predictive value was 0.94. The overall accuracy was 97%.

CONCLUSIONS

The performance of the EP in using FAST scans in BAT patients was encouraging. The high specificity (99%), positive predictive value (0.98), and likelihood ratio for positive tests (86) make it a good 'rule in' tool for BAT patients. The high negative predictive value also makes the FAST scan a useful screening tool. However, ultrasound examination is operator dependent, and FAST scan has its own limitations. For negative FAST scan cases, we recommend a period of monitoring, serial FAST scans, or further investigations, such as CT scan or peritoneal lavage.

Focused assessment with sonography for trauma: the FAST scan

Focused assessment with sonography for trauma or focused abdominal sonography for trauma — the FAST scan, has become a useful modality for the initial evaluation of patients with blunt abdominal trauma. The technique is used to identify free fluid in the abdomen and pelvis and to detect the presence of a pericardial effusion. FAST can be performed by any trained individual, not necessarily a sonographer or radiologist, aiding in the immediate availability of this technique in the emergency situation. We will discuss the applications and sensitivity of this technique in trauma and review the potential pitfalls and limitations which need to be understood if this technique is to be safely applied. The use of FAST for the detection of pneumothoraces in trauma and other advances in FAST scanning, such as scoring systems and paediatric FAST are also reviewed.

Multislice computed tomography in blunt abdominal trauma

Blunt abdominal trauma is a frequent finding in patients with multiple trauma, and is associated with significant morbidity and mortality. Multislice computed tomography (MSCT), allowing for multiplanar reconstructions and three-dimensional images, has become the imaging modality of choice for these patients. MSCT is indicated in all haemodynamically stable patients with suspected blunt abdominal trauma. A `focussed CT' algorithm, as recommended by the Advanced Trauma Life Support (ATLS®) program, may be useful for patients with isolated abdominal trauma who are conscious and cooperative. For unconscious patients with or without multiple trauma `unfocussed' whole-body MSCT algorithms should be used, as these lead to earlier as well as more accurate diagnosis. MSCT allows for rapid diagnosis of abdominal and retroperitoneal injuries and for grading of solid organ injuries. Active haemorrhage may be detected with accuracy similar to angiography. Even bowel, diaphragmatic and bladder injuries, where CT used to miss a significant number of injuries, can be diagnosed with high accuracy by the new generation of MSCT scanners.