The therapeutic impact of abdominal ultrasound in patients with acute abdominal symptoms

Impact of Acute Surgical Assessment Unit Dedicated Ultrasound Access at a Tertiary Care Hospital

Background

Delayed diagnosis, unnecessary hospital admissions and extended length of stay are the problems associated with inappropriate access to radiological investigations. The acute surgical assessment unit (ASAU) in Limerick has two dedicated ultrasound scan (USS) slots daily to overcome this problem. The aim of the current study was to investigate the clinical impact on patient care and the cost-effectiveness of such an ASAU USS access.

Methods

A retrospective review of all patients who underwent USS investigation in the ASAU between May and September 2017 was conducted. Demographic, referral source, presenting complaint, and clinical outcome data were obtained from the ASAU Log. USS data was obtained from the National Integrated Medical System (NIMIS). The Integrated Patient Management System (IPMS) and Therefore Case Manager, Therefore 2014(12.0.2) was utilized to check for any discharged ASAU patient re-presenting to the emergency department (ED) within 30 days.

 Results

A total of 102 patients underwent USS investigation during the study period. The most common presenting complaint was epigastric or right upper quadrant pain (55.8%). Eighty-six patients underwent USS on the same day and the majority (51%) were discharged home with appropriate outpatient follow-up. Approximately 26,000 Euros were saved over four months. Post-discharge ED visits in the ASAU discharged group was zero in the 30 days.

 Conclusion

The ASAU USS dedicated slots in University Hospital Limerick has had a significant positive impact on patient diagnostics, surgical admissions rates and streamlining resource allocation. Having dedicated slots for radiological investigations in the ASAU should become standard of care across all healthcare jurisdictions.

Secondary peritonitis: principles of diagnosis and intervention

Secondary peritonitis accounts for 1% of urgent or emergent hospital admissions and is the second leading cause of sepsis in patients in intensive care units globally. Overall mortality is 6%, but mortality rises to 35% in patients who develop severe sepsis. Despite the dramatic growth in the availability and use of imaging and laboratory tests, the rapid diagnosis and early management of peritonitis remains a challenge for physicians in emergency medicine, surgery, and critical care. In this article, we review the pathophysiology of peritonitis and its potential progression to sepsis, discuss the utility and limitations of the physical examination and laboratory and radiographic tests, and present a paradigm for the management of secondary peritonitis.

Unenhanced areas revealed by contrast-enhanced abdominal ultrasonography with Sonazoid™ potentially correspond to colorectal cancer

The present study investigated the potential utility of contrast-enhanced abdominal ultrasonography (CEUS), using Sonazoid™, in colorectal cancer (CRC). Three patients were subjected to CEUS with Sonazoid™. Surgical specimens were immunostained for CD31. Numbers of blood vessels positive for CD31 were analyzed in each of five fields at ×400 magnification and averaged to determine blood vessel density. Blood vessel density was compared between non-tumorous and tumorous areas. Prior to the administration of Sonazoid™, CRC was illustrated as irregular-shaped wall thickening. One minute after the administration of Sonazoid™, the majority of the thickened wall was enhanced, while some parts of the thickened wall remained unenhanced. Blood vessel densities of non-tumorous and tumorous areas in patient two were 25.2±2.5 and 5.2±1.1 (P<0.0001). Blood vessel densities of non-tumorous and tumorous areas in patient three were 19.0±3.1 and 2.2±0.8 (P<0.0001). Tumorous areas of CRC were not enhanced 1 min after the administration of Sonazoid™. Blood vessel density was lower in tumorous areas compared with non-tumorous areas, as evidenced by immunohistochemistry for CD31. These findings suggest that CEUS may be useful for the determination of the extent of CRC.

A Curious Case of Right Upper Quadrant Abdominal Pain

An otherwise healthy 36-year-old man presented with sudden-onset right upper quadrant abdominal pain and vomiting. A bedside ultrasound, performed to evaluate hepatobiliary pathology, revealed a normal gallbladder but free intraperitoneal fluid. After an expedited CT and emergent explorative laparotomy, the patient was diagnosed with a small bowel obstruction with ischemia secondary to midgut volvulus. Though midgut volvulus is rare in adults, delays in definitive diagnosis and management can result in bowel necrosis. Importantly, an emergency physician must be able to recognize bedside ultrasound findings associated with acutely dangerous intrabdominal pathology.

Acute abdominal pain in children: usefulness of three-view abdominal radiographs in the emergency department

Diagnostic imaging is often an integral component in the workup of a pediatric patient with acute abdominal pain. The purpose of this study was to compare the diagnostic value of a three-view acute abdominal series (AAS) with that of a single supine view (SSV) in children with acute abdominal pain. All subjects aged ≤18 years that underwent an emergency three-view AAS examination for acute abdominal pain at a single urban hospital system were included. Retrospective evaluation of radiological diagnosis, number of radiological images, further imaging, management, and clinical outcomes was performed. "Positive" AAS studies were compared with corresponding SSV images for direct comparison of diagnostic value. Standard nonparametric statistical evaluation was performed. Five hundred forty-one AAS studies were included in the study. Greater than three radiographs were acquired in 29 % (153/541) of the subjects. Two hundred ninety-nine out of 541 AAS studies included a technically adequate SSV of the abdomen and pelvis. Most AAS examinations were categorized as negative (n = 485; 90 %). Of the 56 examinations initially classified as positive, there was no significant statistical difference between diagnostic accuracy between the AAS and SSV on retrospective evaluation. For pediatric subjects with nontraumatic acute abdominal pain, the yield of conventional radiographic study is exceedingly low. If required, a technically adequate single supine anteroposterior (AP) view of the abdomen and pelvis is sufficient for initial radiographic evaluation while reducing unnecessary radiation exposure to the patient.

Characteristics of colorectal cancer diagnosed with screening abdominal ultrasonography

Patient records were retrospectively analyzed to elucidate the characteristics of patients with colorectal cancer (CRC) diagnosed with screening abdominal ultrasound (US). Patients diagnosed with CRC using abdominal US [localized irregular wall thickening (W) or a hypoechoic mass with a hyperechoic mass (M)] were enrolled. The patients were subjected to colonoscopy and treated surgically between March, 2010 and January, 2015. A total of 5 men (aged 74.0±0.8 years) and 10 women (aged 73.0±12.0 years) were analyzed. Stratification was analyzed with abdominal US. The threshold value of wall thickness to diagnose CRC was investigated with receiver operating characteristic (ROC) curve analysis. The average wall thickness was 2.8±0.4 mm in the surrounding normal tissue and 12.7±5.2 mm in CRC (one-way analysis of variance, P<0.0001). The wall was significantly thicker in CRC compared with the normal colonic wall. The calculated threshold value was 4.3 mm for the diagnosis of CRC. Stratification was preserved in W, while it was lost in M (Chi-squared test, P=0.0196). The hemoglobin concentration was lower, while the C-reactive protein, carcinoembryonic antigen and carbohydrate antigen 19-9 levels were elevated above normal values. The threshold value was 4.3 mm for the diagnosis of CRC with abdominal US.

Use of advanced imaging techniques during visits to emergency departments--implications, costs, patient benefits/risks

25 years ago, on a Friday evening at 9 pm, the emergency department (ED) was full of patients with a wide range of clinical problems. Their investigations included plain radiographs, but no other imaging was included until the next working day. At present, many patients are receiving advanced imaging such as ultrasound, CT and MRI, often delivered out of hours--an obvious advance for patients or sometimes an unnecessary development? In this article, we will consider how to assess patient benefits and whether increased use of advanced imaging is an overall advance for patients. We will address the general implications for healthcare services which come with greater use of advanced imaging. We will then address the effect of advanced imaging on individual fictional ED patients with a variety of complaints.

Spectrum of diseases and diagnostic values of ultrasound in adult patients with nontraumatic acute abdomen in a nigerian tertiary health facility

Aim and Objective:

The purpose of this study was to determine the spectrum of disease on abdominal ultrasound (US) and the diagnostic efficacy of US in adult patients with nontraumatic acute abdomen at Obafemi Awolowo University Teaching Hospitals Complex (OAUTHC), Ile-Ife.

Materials and Methods:

The study population included consecutive 150 adult patients aged 15 years and above presenting with nontraumatic acute abdomen via the adult emergency unit or as inpatients referred to the Radiology Department of OAUTHC, Ile-Ife for abdominal US. MINDRAY D.C-6 real-time US scanner with 3.5, 5.0, and 7.5 MHz probes and Doppler facilities were used to assess the intra-abdominal organs and the findings were compared with the clinical and surgical findings in those cases that were operated.

Results:

The common spectrum of diseases encountered on US in this study included appendicitis (66 [44%]), ectopic pregnancy (34 [22%]), intestinal obstruction (13 [8.7%]) while the least finding was renal abscess 1 (0.7%). The correlation of US findings with surgical findings in this study showed sensitivity, specificity, and kappa agreement for appendicitis of 83.3%, 100.0%, and 0.808; ectopic pregnancy of 100.0%, 97.8%, and 0.958; acute cholecystitis of 100.0%, 100.0%, and 1.0. However, perforated viscus showed the least sensitivity (60.0%), specificity (99.2%), and kappa agreement 0.654. All the disease entities showed good kappa agreement beyond chance, and they were all statistically significant (P < 0.001).

Conclusions:

This study has shown a relatively high sensitivity, specificity and diagnostic accuracy of US in cases of nontraumatic acute abdomen in a careful hand. We, therefore, recommended that these advantages of US should be capitalized upon in settings where other advanced diagnostic modalities are not available.

The role of US examination in the management of acute abdomen

Acute abdomen is a medical emergency, in which there is sudden and severe pain in abdomen of recent onset with accompanying signs and symptoms that focus on an abdominal involvement. It can represent a wide spectrum of conditions, ranging from a benign and self-limiting disease to a surgical emergency. Nevertheless, only one quarter of patients who have previously been classified with an acute abdomen actually receive surgical treatment, so the clinical dilemma is if the patients need surgical treatment or not and, furthermore, in which cases the surgical option needs to be urgently adopted. Due to this reason a thorough and logical approach to the diagnosis of abdominal pain is necessary. Some Authors assert that the location of pain is a useful starting point and will guide a further evaluation. However some causes are more frequent in the paediatric population (like appendicitis or adenomesenteritis) or are strictly related to the gender (i.e. gynaechologic causes). It is also important to consider special populations such as the elderly or oncologic patients, who may present with atypical symptoms of a disease. These considerations also reflect a different diagnostic approach. Today, surely the integrated imaging, and in particular the use of multidetector Computed Tomography (MDCT) has revolutionised the clinical approach to this condition, simplyfing the diagnosis but burdening the radiologists with the problems related to the clinical management. However although CT emerging as a modality of choice for evaluation of the acute abdomen, ultrasonography (US) remains the primary imaging technique in the majority of cases, especially in young and female patients, when the limitation of the radiation exposure should be mandatory, limiting the use of CT in cases of nondiagnostic US and in all cases where there is a discrepancy between the clinical symptoms and negative imaging at US.

Accuracy of 64-row multidetector CT in the diagnosis of surgically treated acute abdomen

OBJECTIVE

To assess the accuracy of 64-row computed tomography (CT) in the differential diagnosis of acute abdomen in the emergency department.

MATERIALS AND METHODS

Prospective analysis of 181 patients with surgically treated acute abdomen.

RESULTS

In 158/181 cases, CT was totally concordant with surgical repertoire. Partial concordance was found in 15 cases. Overall sensitivity was 87.3% when only cases of complete concordance were considered, 95.6% if also partial concordance cases were included.

CONCLUSION

CT showed high reliability in the differential diagnosis of acute abdomen surgically treated, although associated conditions can sometimes be missed.

Factors predicting significant pathology on ultrasonography in women presenting with non-specific lower abdominal pain

INTRODUCTION

Ultrasonography is used frequently to exclude significant pathology in young women presenting with non-specific lower abdominal pain (NSLAP). This study examined parameters that predicted the likelihood of significant findings on ultrasonography. These results could be used to select patients for priority imaging or identify those who could be managed with no ultrasonography.

METHODS

A total of 65 women with NSLAP were identified from 283 admissions. Group 1 (n=42) consisted of patients with normal imaging. Group 2 (n=23) included patients with 'positive' scans requiring treatment. White cell count (WCC), C-reactive protein (CRP) levels, platelet count, age, duration of pain and length of stay in hospital were compared between the groups.

RESULTS

The median WCC and CRP were greater in Group 2 than in Group 1: 15 x 10(9)/l and 123 mg/l versus 11 x 10(9)/l and 72 mg/l respectively (p=0.01 and p=0.05). CRP was a weak predictor of positive pathology on ultrasonography (area under curve [AUC]=0.66, p=0.027) and WCC was a strong predictor of abnormal pathology on ultrasonography (AUC=0.7, p=0.005). A WCC of >12.8 x 10(9)/l was 65% sensitive and 71% specific in predicting subsequent pathology on ultrasonography. The median wait for ultrasonography was 24 hours (range: 1-96 hours).

CONCLUSIONS

This study failed to define any criteria that could select patients not requiring ultrasonography. Since ultrasonography is a relatively cheap and safe investigation, its continued use to screen women with NSLAP is justified. WCC should be used to prioritise imaging.

[Acute abdomen: clinical background and demands on imaging]

The term "acute abdomen" does not describe a specific disease entity but is more a critical clinical state which incorporates very heterogeneous clinical presentations. The prognosis of any disease depends on the time frame from the onset of symptoms to the initiation of a specific therapy. For this reason there are special expectations by clinicians regarding the diagnostic assessment provided by radiology which is expected to deliver an immediate diagnosis supporting further therapeutic decisions. Along with the patient's clinical history, physical examination and blood tests, radiological diagnostics are essential for enabling a specific treatment. From a surgical point of view the radiologist is expected to help in differentiating between cases with indications for emergency surgery and cases eligible for elective surgery or conservative treatment.

Imaging patients with acute abdominal pain

Acute abdominal pain may be caused by a myriad of diagnoses, including acute appendicitis, diverticulitis, and cholecystitis. Imaging plays an important role in the treatment management of patients because clinical evaluation results can be inaccurate. Performing computed tomography (CT) is most important because it facilitates an accurate and reproducible diagnosis in urgent conditions. Also, CT findings have been demonstrated to have a marked effect on the management of acute abdominal pain. The cost-effectiveness of CT in the setting of acute appendicitis was studied, and CT proved to be cost-effective. CT can therefore be considered the primary technique for the diagnosis of acute abdominal pain, except in patients clinically suspected of having acute cholecystitis. In these patients, ultrasonography (US) is the primary imaging technique of choice. When costs and ionizing radiation exposure are primary concerns, a possible strategy is to perform US as the initial technique in all patients with acute abdominal pain, with CT performed in all cases of nondiagnostic US. The use of conventional radiography has been surpassed; this examination has only a possible role in the setting of bowel obstruction. However, CT is more accurate and more informative in this setting as well. In cases of bowel perforation, CT is the most sensitive technique for depicting free intraperitoneal air and is valuable for determining the cause of the perforation. Imaging is less useful in cases of bowel ischemia, although some CT signs are highly specific. Magnetic resonance (MR) imaging is a promising alternative to CT in the evaluation of acute abdominal pain and does not involve the use of ionizing radiation exposure. However, data on the use of MR imaging for this indication are still sparse.

SUPPLEMENTAL MATERIAL

http://radiology.rsna.org/content/253/1/31/suppl/DC1.

Imaging strategies for detection of urgent conditions in patients with acute abdominal pain: diagnostic accuracy study

OBJECTIVE

To identify an optimal imaging strategy for the accurate detection of urgent conditions in patients with acute abdominal pain.

DESIGN

Fully paired multicentre diagnostic accuracy study with prospective data collection.

SETTING

Emergency departments of two university hospitals and four large teaching hospitals in the Netherlands.

PARTICIPANTS

1021 patients with non-traumatic abdominal pain of >2 hours' and <5 days' duration. Exclusion criteria were discharge from the emergency department with no imaging considered warranted by the treating physician, pregnancy, and haemorrhagic shock.

INTERVENTION

All patients had plain radiographs (upright chest and supine abdominal), ultrasonography, and computed tomography (CT) after clinical and laboratory examination. A panel of experienced physicians assigned a final diagnosis after six months and classified the condition as urgent or non-urgent.

MAIN OUTCOME MEASURES

Sensitivity and specificity for urgent conditions, percentage of missed cases and false positives, and exposure to radiation for single imaging strategies, conditional imaging strategies (CT after initial ultrasonography), and strategies driven by body mass index and age or by location of pain.

RESULTS

661 (65%) patients had a final diagnosis classified as urgent. The initial clinical diagnosis resulted in many false positive urgent diagnoses, which were significantly reduced after ultrasonography or CT. CT detected more urgent diagnoses than did ultrasonography: sensitivity was 89% (95% confidence interval 87% to 92%) for CT and 70% (67% to 74%) for ultrasonography (P<0.001). A conditional strategy with CT only after negative or inconclusive ultrasonography yielded the highest sensitivity, missing only 6% of urgent cases. With this strategy, only 49% (46% to 52%) of patients would have CT. Alternative strategies guided by body mass index, age, or location of the pain would all result in a loss of sensitivity.

CONCLUSION

Although CT is the most sensitive imaging investigation for detecting urgent conditions in patients with abdominal pain, using ultrasonography first and CT only in those with negative or inconclusive ultrasonography results in the best sensitivity and lowers exposure to radiation.

The role of ultrasonography in the diagnosis and management of non-traumatic acute abdominal pain

Our aim was to assess the effects of initial ultrasonography (US) evaluation on the diagnosis and management of non-traumatic acute abdominal pain in the emergency department. Three hundred patients with the complaint of non-traumatic acute abdominal pain who were sent for US examination with an initial clinical impression were included in the study. Pre-US and post-US surveys were designed for the clinicians who requested US. The percentage concordance of US findings with the discharge diagnosis made by clinical follow-up, imaging modalities and surgery was determined by calculating the confidence interval. The concordance of the initial clinical impression and the US diagnosis with the discharge diagnosis were compared using the McNemar test. US could not detect any pathology in 102 (34%; 95%CI, 28.6-39.3%) of the patients. The US revealed a different diagnosis than the clinical impression in 69 (23%; 95%CI, 18.2-27.7%), and confirmed the diagnosis in 121 (40%; 95%CI, 34.4-45.5%) patients. The US changed the treatment plans in 47% (95%CI, 41.3-52.6%) of the patients. The clinicians stated US helped them "very much" or "moderately" in making a diagnosis in 83% (95%CI, 78.7-87.2%). When US results were compared with the discharge diagnosis, there was concordance in 238 (79.3%; 95%CI, 74.3-83.6%) patients but not in 62 (20.6%; 95%CI, 16-25.1%). Among 121 patients the initial clinical impression agreed with the US diagnosis and there was concordance with the discharge diagnosis in 105 (86.7%; 95%CI, 80-92.7%). The concordance of US findings with the discharge diagnosis was significantly higher than that of the initial clinical impression statistically. In the initial evaluation of the patients with acute abdominal pain, US is considerably helpful in making the correct diagnosis, and that the concordance with the discharge diagnosis is high. When whole abdominal scanning is not performed, targeted US study according to the initial clinical impression decreases the clinical benefit of US.

Decision making in patients with acute abdominal pain at a university and at a rural hospital: does the value of abdominal sonography differ?

Introduction and objectives

Abdominal sonography is regarded as a quick and effective diagnostic tool for acute abdominal pain in emergency medicine. However, final diagnosis is usually based on a combination of various clinical examinations and radiography. The role of sonography in the decision making process at a hospital with advanced imaging capabilities versus a hospital with limited imaging capabilities but more experienced clinicians is unclear.

The aim of this pilot study was to assess the relative importance of sonography and its influence on the clinical management of acute abdominal pain, at two Swiss hospitals, a university hospital (UH) and a rural hospital (RH).

Methods

161 patients were prospectively examined clinically. Blood tests and sonography were performed in all patients. Patients younger than 18 years and patients with trauma were excluded. In both hospitals, the diagnosis before and after ultrasonography was registered in a protocol. Certainty of the diagnosis was expressed on a scale from 0% to 100%.

The decision processes used to manage patients before and after they underwent sonography were compared. The diagnosis at discharge was compared to the diagnosis 2 – 6 weeks thereafter.

Results

Sensitivity, specificity and accuracy of sonography were high: 94%, 88% and 91%, respectively.

At the UH, management after sonography changed in only 14% of cases, compared to 27% at the RH. Additional tests were more frequently added at the UH (30%) than at the RH (18%), but had no influence on the decision making process-whether to operate or not. At the UH, the diagnosis was missed in one (1%) patient, but in three (5%) patients at the RH. No significant difference was found between the two hospitals in frequency of management changes due to sonography or in the correctness of the diagnosis.

Conclusion

Knowing that sonography has high sensitivity, specificity and accuracy in the diagnosis of acute abdominal pain, one would assume it would be an important diagnostic tool, particularly at the RH, where tests/imaging studies are rare.

However, our pilot study indicates that sonography provides important diagnostic information in only a minority of patients with acute abdominal pain.

Sonography was more important at the rural hospital than at the university hospital. Further costly examinations are generally ordered for verification, but these additional tests change the final treatment plan in very few patients.

Acute appendicitis: meta-analysis of diagnostic performance of CT and graded compression US related to prevalence of disease

PURPOSE

This study was a head-to-head comparison of graded compression ultrasonography (US) and computed tomography (CT) in helping diagnose acute appendicitis with an emphasis on diagnostic value at different disease prevalences, commonly occurring in various hospital settings.

MATERIALS AND METHODS

MEDLINE, EMBASE, CINAHL, and Cochrane databases were searched from January 1966 to February 2006. Prospective trials were selected if they (a) compared graded compression US and CT in the same patient population; (b) included more than 10 patients, otherwise, the study was considered a case report; (c) evaluated mainly adults or adolescents; (d) used surgery and/or clinical follow-up as reference standard; and (e) reported data to calculate 2 x 2 contingency tables for graded compression US and CT. Estimates of sensitivity, specificity, and positive and negative likelihood ratios (LRs) for US and CT were calculated. Posttest probabilities after CT and US were calculated for various clinically relevant prevalences.

RESULTS

Six studies were included, evaluating 671 patients (mean age range, 26-38 years); prevalence of acute appendicitis was 50% (range, 13%-77%). Positive LR was 9.29 (95% confidence interval [CI]: 6.9, 12.6) for CT and 4.50 (95% CI: 3.0, 6.7; P = .011) for US, yielding posttest probabilities for positive tests of 90% and 82%, respectively. Negative LR was 0.10 (95% CI: 0.06, 0.17) for CT and 0.27 (95% CI: 0.17, 0.43) for US (P = .013), resulting in posttest probabilities of 9% and 21%, respectively. Posttest probabilities for positive tests were markedly decreased at lower prevalences.

CONCLUSION

In head-to-head comparison studies of diagnostic imaging, CT had a better test performance than did graded compression US in diagnosing appendicitis. Ignoring the relationship between prevalence (pretest probability) and diagnostic value may lead to an inaccurate estimation of diagnostic performance.

Assessing diagnostic confidence: a comparative review of analytical methods

RATIONALE AND OBJECTIVES

The ability of a test to influence diagnostic confidence is used as a measure of its efficacy. Our aim was to compare analytic methods that evaluate changes in confidence.

MATERIALS AND METHODS

The approaches compared were "basic," "retained diagnoses," "Omary," "Tsushima," and "score-based" methods. For illustration, data from a clinical study assessing changes in diagnostic confidence (0%-100%) before and after abdominopelvic computed tomography (CT) in patients with acute abdominal pain were used.

RESULTS

The basic, retained diagnoses and Omary methods all ignore whether the test yields a correct diagnosis (confident, but incorrect, diagnoses are regarded positively). Although the Tsushima method takes some account of diagnostic accuracy, all misdiagnoses are considered equal. The score-based method addresses some of the fundamental limitations in the other analytical methods, such as diagnostic accuracy and the varying nature of different misdiagnoses. In the case study, mean (SD) diagnostic confidence for the cohort as a whole (n = 62) increased following CT: 50.7% (20.8%) to 73.2% (20.9%). Pretest diagnoses were changed following CT in 43% (27 of 62) of patients. Pretest diagnoses proved to be incorrect in 52% (32 of 62), and post-test diagnoses incorrect in as many as 19% (12 of 62) of patients. All five analytic methods indicated a positive contribution for CT (all P < or = .003).

CONCLUSION

Although our illustrative case study revealed no consequential differences across the five methods, there remain substantial differences in the fundamental principles underlying them that should affect choice of analytic method when assessing diagnostic confidence.

Analysis of diagnostic confidence and diagnostic accuracy: a unified framework

Diagnostic confidence has been used as a measure of diagnostic efficacy, but this measure in isolation fails to take into account incorrect diagnoses. Conventional analytical approaches of diagnostic confidence ignore associated diagnostic accuracy. To address this limitation, we introduce a unifying framework which incorporates diagnostic confidence, changes in diagnoses and ultimate accuracy. The framework is illustrated using data from a study in which 62 patients with acute abdominal pain prospectively underwent CT. Admitting surgeons documented their diagnoses and graded their diagnostic confidences (on a 5-point scale) on admission and again after CT. Our approach, unlike conventional analyses, incorporates knowledge of final diagnoses, obtained from surgery or 6 months follow up, in assessing the impact of the test (on a 9-point scale). Changes in pre- and post-CT confidence scores were assessed by the one-sample t-test comparing against zero change, with the test statistic acting as a standardized quantity allowing comparison between our and conventional methodological approaches. Overall, 52% (32/62) of patients were misdiagnosed on admission and 19% (12/62) had incorrect post-CT diagnoses. Diagnostic confidence following CT increased significantly compared with pre-CT confidence on applying both analytical methods, although the level of statistical significance was less marked using our approach. Mean (95% confidence interval) increase in confidence under conventional analysis was 1.32 (1.03, 1.62), with standardized score t = 8.90 [p<0.0001], whereas our method yielded 0.69 (0.25, 1.13), with standardized score t = 3.12 [p = 0.003]. Although both analytical methods led to the same inference regarding the efficacy of CT in the illustrative case study presented, they differed somewhat in degree. It is conceivable that disparate conclusions may emerge in other studies and circumstances. Failure to take adequate account of incorrect diagnoses is potentially misleading. We suggest that a comprehensive analysis of diagnostic confidence requires the incorporation of diagnostic accuracy.

[Diagnostic and therapeutic management of acute abdomen in Hajah, Yemen]

We report on the results of surgical treatment in 236 patients admitted with clinical signs of acute abdomen between the 1st of January 2000 and the 31st of December 2003 at the District Hospital of Hajah in northwest Yemen. Hajah, a city 2500 m above sea level, has 60,000 inhabitants and serves an area with 800,000 inhabitants. The hospital was funded by the Saudi Arabian government and built in 1997. Data on patients with acute abdominal pain were prospectively collected and analysed according to diagnosis, age, sex, and duration of symptoms. The most frequent cause was acute appendicitis, followed by incarcerated inguinal hernia. Complicated ulcer diseases of the upper gastrointestinal tract and gynaecological disorders were also frequently diagnosed. Gunshot wounds were the most frequent trauma. Despite the limited diagnostic equipment at the Hajah District Hospital and the short duration of hospital stay, there was no fatal event during the 1-year period analysed. The management of patients with acute abdominal pain and the ability to arrive at exact diagnosis is dependent on the availability of diagnostic means such as abdominal ultrasound and CT scan. However, especially in rural countries with only rudimentary technology, far more depends on the professional training and qualification of the surgeons responsible.