Emergency ultrasound-based algorithms for diagnosing blunt abdominal trauma

BACKGROUND

Ultrasonography is regarded as the tool of choice for early diagnostic investigations in patients with suspected blunt abdominal trauma. Although its sensitivity is too low for definite exclusion of abdominal organ injury, proponents of ultrasound argue that ultrasound-based clinical pathways enhance the speed of primary trauma assessment, reduce the number of computed tomography scans and cut costs.

OBJECTIVES

To assess the efficiency and effectiveness of trauma algorithms that include ultrasound examinations in patients with suspected blunt abdominal trauma.

SEARCH STRATEGY

We searched MEDLINE, EMBASE, CENTRAL, CCMED, publishers' databases, controlled trials registers and the Internet. Bibliographies of identified articles and congress abstracts were handsearched. Trials were obtained from the Cochrane Injuries Group's trials register. Authors were contacted for further information and individual patient data.

PARTICIPANTS

patients with blunt torso, abdominal or multiple trauma undergoing diagnostic investigations for abdominal organ injury.

INTERVENTIONS

diagnostic algorithms comprising emergency ultrasonography (US).

CONTROLS

diagnostic algorithms without US ultrasound examinations (e.g. primary computed tomography [CT] or diagnostic peritoneal lavage [DPL]).

OUTCOME MEASURES

mortality, use of CT and DPL, cost-effectiveness, laparotomy and negative laparotomy rates, delayed diagnoses, and quality of life.

STUDIES

randomised controlled trials (RCTs) and quasi-randomised trials (qRCTs).

DATA COLLECTION AND ANALYSIS

Two reviewers independently selected trials for inclusion, assessed methodological quality and extracted data. 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- or random-effects modelling, as appropriate.

MAIN RESULTS

We identified two RCTs with US in the experimental arm and another with US in the control group. We also considered two qRCTs. Overall, trials were of moderate methodological quality. Few authors responded to our written inquiries seeking to resolve controversial issues and to obtain individual patient data. We were able to pool data from two trials comprising 1037 patients for primary endpoint analysis (i.e. mortality). The relative risk in favour of the no-US arm was 1.4 (95% CI 0.94 to 2.08). Because of a lack of details, the meaning of this observation remains unclear. There was a marginal benefit with US-based pathways in reducing CT scans (random-effects RD -0.46; 95% CI -1.00 to 0.13), offset by trials of higher methodological rigour. No differences were observed in DPL and laparotomy rates.

AUTHORS' CONCLUSIONS

There is insufficient evidence from RCTs to justify promotion of ultrasound-based clinical pathways in diagnosing patients with suspected blunt abdominal trauma.

Ein Rapid Review zur Mindestmengenproblematik am Beispiel der Knietotalendoprothese

We set out to clarify whether in hospitals with a large volume morbidity and mortality rates after total knee arthroplasty (TKA) can be improved, whether the effects are consistent, and whether minimum recommendable caseloads can be inferred. We conducted a systematic review using MEDLINE, EMBASE, CENTRAL, and CINAHL and performed a hand search without restrictions on language or publication types. We identified 1406 citations, of which 13 studies including 1,110,962 patients met our inclusion criteria. Of these, six studies explored the same administrative data source. Five studies enrolling 448,897 were eligible for quantitative analysis. All studies corresponded to evidence level 2b (prospective or retrospective cohort study with >80% follow-up). We found homogeneous results about hospital mortality. Between 2551 and 821 TKA must be performed by high-volume rather than by low-volume providers to prevent 1 extra death. Absolute event rates are notably small.

[Emergency ultrasound for blunt abdominal trauma--meta-analysis update 2003]

Emergency ultrasound has established itself as a key procedure of primary diagnostic work-up for blunt abdominal and multiple trauma. However, in a systematic review published in 2001 ultrasonography turned out to provide an unexpectedly low sensitivity. We conducted an update of this analysis to investigate if test characteristics will be maintained including recent studies. Prospective trials published between January 1957 and January 2003 were identified using the Medline/Oldmedline, Embase and Cochrane Controlled Trials Register databases. The searching strategy comprised a manual search as well as a search along the world-wide web. Qualitative rating was carried out by two investigators using criteria proposed by the Centre for Evidence-Based Medicine, Oxford. We investigated a composite endpoint (i. e., free fluid and/or organ laceration) as well as the single criteria organ injury and free intraabdominal fluid collections. After calculation of two-by-two-tables, Summary Receiver Operating Characteristics (SROC) and Q* values were determined together with their 95% confidence intervals. The Q* value was proposed as the point of intersection where sensitivity equals specificity. In addition, a random effects model was employed to compute common positive and negative likelihood ratios (LR). By assessing the title and/or abstract, 349 of 957 papers contained potentially valid information for the purpose of this review. A total of 67 studies were deemed eligible, nine of which had to be excluded from meta-analysis because of dual publication. This left 58 trials allocating 16,361 subjects for statistical analysis. Despite a trend towards improved study designs observed during the past decade, the included trials were of average methodological quality. Two-thirds of all investigations fulfilled two or less of the six possible quality criteria. The diagnostic reference standard was applied independently in only 40% of all protocols. With regard to the composite endpoint and the sonographic depiction of free fluid, the Q* value was estimated at 0.91, whereas Q* equaled 0.90 for the detection of organ injury. Q* values subsequently decreased with improving study quality and fell clearly below 0.80 in methodologically proper studies. Accounting for a negative LR of 0.23 (composite endpoint) and an assumed prevalence of 35% of intraabdominal injury, a post-test probability of 11% will remain in case of a negative sonogram. In pediatric trauma, ultrasound showed even worse test characteristics (negative LR = 0.43). Thus, in case of a 35% prevalence, the post-test probability has to estimated at 19%. Emergency ultrasound provides high specificity but insufficient sensitivity to reliably rule out intraabdominal injury.

Dose Finding Study for Combination Treatment with Topotecan and Gemcitabine of Patients with Recurrent Ovarian Cancer after Failure of First-Line Chemotherapy with Paclitaxel and Platinum

OBJECTIVES

Topotecan and gemcitabine have shown mono-activity against different solid tumors including recurrent ovarian cancer after failure of platinum- and paclitaxel-containing therapies. Both drugs affect DNA replication, topotecan additionally inhibits the DNA repair process. Efficacy profiles and different mechanisms of action make the combination of both drugs a promising regimen. Therefore the following dose-finding study was conducted to determine the maximum tolerated dose (MTD) and the dose-limiting toxicities (DLT) of this combination. Based on the monotherapy schedules topotecan was given on day 1-5, and gemcitabine on day 1 + 8 every 21 days.

PATIENTS AND METHODS

Patients with histologically proven ovarian cancer who relapsed after platinum- and paclitaxel-containing therapy were enrolled. 3 different dose levels were investigated. No individual dose escalation or primary use of cytokines were allowed.

RESULTS

23 patients were enrolled, 50% were pretreated with at least 2 platinum-containing therapies; 80 courses were analyzed for toxicity. Thrombocytopenia and leucopenia were the major DLTs. The MTD for phase II trials is 0.50 mg/m(2) topotecan and 800/600 mg/m(2) gemcitabine. In this dose level only one therapy-related non-hematological adverse event >grade 2 (grade 3 mycotic stomatitis) and one grade 4 thrombocytopenia occurred. Responses were observed in 6 and stable disease in 4 out of 12 evaluable patients. Median survival was 15.3 (95% CI: 13.2-28.6) months.

CONCLUSIONS

The results of this phase I study demonstrate the feasibility and tolerability of this new combination in heavily pretreated patients. Based on these results a phase II study was initiated to evaluate the efficacy of this regimen.

A likelihood ratio approach to meta-analysis of diagnostic studies

OBJECTIVE

To develop a clinically and methodologically sound approach to diagnostic meta-analysis.

METHODS

Two-step model was used involving four fictitious sets of 10 studies each with varying sensitivity and specificity; this was followed by the application of the method to data from a published systematic review of emergency ultrasound. Multidimensional test characteristics (relating to the detection or exclusion of the condition of interest) were described by likelihood ratio scatterplots and pooled likelihood ratios. Likelihood ratios summarise the ability of a test to revise the prior probability of disease. They can be summarised by established fixed-effects and random-effects methods.

RESULTS

Likelihood ratios precisely describe both directions of test performance. By plotting positive against negative likelihood ratios, together with their 95% confidence intervals, a multidimensional forest plot is obtained that can be interpreted in analogy to therapeutic meta-analyses. There are accepted threshold values of positive and negative likelihood ratios (i.e. 10.0 and 0.1) to recommend a test for clinical use. In the matrix space, distinct test characteristics can even be assessed by eyeballing. With regard to data from the real meta-analysis, the suggested high discriminatory power of ultrasound was only partially qualified by likelihood ratios. The positive value confirms the reliability of a positive scan, whereas the negative value questions a normal sonogram.

CONCLUSIONS

A full characterisation of test performance requires multidimensional effect measures. Likelihood ratios are recommended descriptors of the two dimensions of diagnostic research evidence and provide a convenient means to visualise and to communicate results as weighted summary estimates of a diagnostic meta-analysis.

[Diagnostic efficacy of gadodiamide-enhanced dynamic examination technique in comparison to conventional magnet resonance tomography in exacerbated chronic osteomyelitis]

PURPOSE

To evaluate the diagnostic effectiveness of dynamic gadodiamide-enhanced MRI in discriminating reparative tissue formation from florid inflammation in patients with chronic osteomyelitis.

MATERIALS AND METHODS

Subjects with chronic osteomyelitis and clinically suspected exacerbation were consecutively enrolled into a prospective trial. Following conventional contrast-enhanced MRI scanning, a dynamic contrast-enhanced SE sequence was carried out in all patients (acquisition interval 58 s, 11 repetitions with a total acquisition time of 11 minutes). The relative increase of the time-dependent signal intensity was assessed in representative circular regions of interest placed over bone marrow and surrounding soft tissues. As diagnostic reference standard, histologic and intraoperative findings were obtained independently from the result of the index test. The MRI studies were evaluated by two radiologists who were blinded to the findings of the reference test.

RESULTS

30 of 51 patients were subsequently scheduled for surgery (mean age 42.6 +/- 12.7 years, 27 males). 19 cases had a florid granulocytic infection, with 6 cases showing histologic signs of putrid liquefaction. Another 11 patients had chronic-granulating, fibrosing osteomyelitis. The course of the signal-time curves differed significantly between the different pathologic processes (multiple measures ANOVA, p < 0,001) in both bone marrow and soft tissue. The areas under the receiver operating characteristics (ROC) curves of the dynamic sequence as a performance measure to distinguish between acute and chronic infection were 0.73 (95 % confidence interval 0.41 - 1.00) and 0.82 (95 % confidence interval 0.59 - 1.00), respectively. Although no overall difference was found in diagnostic efficacy between conventional and dynamic MRI, the dynamic technique provided important additional information for equivocal conventional results.

CONCLUSION

Dynamic contrast-enhanced MRI scanning is a safe and potentially valuable tool to discriminate between florid and chronic inflammation in documented osteomyelitis.

[Clinical trials in orthopedic and trauma surgery: randomized or non-randomized?]

Drawing inferences on a causal relationship between a particular intervention and the observed outcome requires to conduct a clinical experiment which controls for study conditions and systematic errors (bias). This is best to be achieved by randomization in which known and unknown biological risk factors are distributed equally among treatment arms. Trauma and orthopedic surgery,however, occupies an exceptional position in clinical medicine. Random allocation of subjects is often considered difficult because of the tight time frame between patient presentation and the urgent need for surgical treatment, and the dependence of operative results upon technical skills. Evidence of a true treatment effect does not only depend on design issues (i.e., randomized or non-randomized treatment assignment), but on both the prior probability of efficacy and the observed effect size as well. Even though our knowledge of the efficacy of osteosynthesis comparing with, let's say, plaster immobilization or (fictive) placebo therapy is hardly supported by randomized trials, the biologically plausible principle of stable operative fixation of fracture fragments has established itself as the scientific basis to propagate surgical rather than other treatment options. Thus, the efficacy of a medical intervention can be well demonstrated without randomization. Regarding the ultimate goals of stabilization, pain removal, and mobilization,osteosynthesis of a pertrochanteric fracture fits these principles in terms of an all-or-none effect (so called level Ic evidence): without the intervention, effects will not be observed. On the other hand, endpoints such as healing and infection rates or duration of rehabilitation may be severely influenced by confounding factors (e.g., concomitant diseases, age, or gender). Under these circumstances,the goal of quantifying treatment effects of different interventions (i.e., interlocking nails, plates, K-wires) and of discriminating these effects from bias might be solved more reliably by a randomized than by a non-randomized trial.Obviously,the need for randomization relies on the choice of the main endpoint of interest.The postulated overestimation of treatment effects by nonrandomized trials has been proven only for methodologically weak investigations. In contrast, high quality studies led to comparable findings regardless of randomization. In conclusion, there are thinkable alternative designs to randomized trials in trauma surgery, accounting for selected clinical questions and objectives. It must be emphasized that these designs will require a similarly rigorous planning (i.e., study protocols, ethics, sample size considerations) and analysis of the results.

A phase II study of topotecan plus gemcitabine in the treatment of patients with relapsed ovarian cancer after failure of first-line chemotherapy

BACKGROUND

Second-line chemotherapy for patients with ovarian cancer who failed platinum and paclitaxel treatment remains a therapeutic challenge. We investigated the toxicity profile and therapeutic efficacy of a novel combination regimen, topotecan plus gemcitabine, in a clinical phase II study.

PATIENTS AND METHODS

Women with relapsed epithelial ovarian cancer after platinum and paclitaxel treatment were eligible to participate in this trial. Topotecan was given at an initial dose of 0.5 mg/m(2) daily (days 1-5), combined with gemcitabine 800 mg/m(2) and 600 mg/m(2) on days 1 and 8, respectively. Precluding good tolerability, this protocol facilitated subsequent dose increases of topotecan up to 1.0 mg/m(2). The primary objective was to determine the dose-limiting toxicity, whereas secondary objectives comprised measurable and CA-125 response rates, disease-free and overall survival.

RESULTS

The twenty-one patients (median age 57 years, range 37-70 years) who were allocated to this trial received a total of 94 courses of chemotherapy. Median follow-up was 20.5 months. Topotecan dosage could be escalated to 0.75 mg/m(2) in nine patients and 1 mg/m(2) in another two patients. Dose reduction was not necessary in any case. There were no episodes of neutropenic fever, sepsis or chemotherapy-related fatalities. Only one patient developed CTC grade 4 leukopenia after the first treatment cycle, whereas three patients showed grade 3/4 anaemia. Five patients experienced thrombocytopenia grade 4 without clinical sequelae. Non-hematological toxicities were mild and rare. Eleven patients could be evaluated for clinical tumour response, with three complete, and four partial remissions. Two patients each had stable and progressive diseases. The median progression-free survival rate was 8.8 months [95% confidence interval (CI) 6.3-13.4 months]. The median overall survival rate was 21.1 months (95% CI 14.8-22.1 months).

CONCLUSIONS

Topotecan combined with gemcitabine has a favourable toxicity profile and encouraging efficacy in patients with recurrent ovarian cancer.

Arg123-Tyr166 domain of human ApoA-I is critical for HDL-mediated inhibition of macrophage homing and early atherosclerosis in mice

Atherosclerosis was studied in apolipoprotein E (apoE) knockout mice expressing human apolipoprotein A-I (apoA-I) or an apoA-I/apolipoprotein A-II (apoA-II) chimera in which the Arg123-Tyr166 central domain of apoA-I was substituted with the Ser12-Ala75 segment of apoA-II. High density lipoprotein (HDL) cholesterol levels were identical in apoA-I and apoA-I/apoA-II mice, but at 4 months, plaques were 2.7-fold larger in the aortic root of the apoA-I/apoA-II mice (P<0.01). The macrophage-to-smooth muscle cell ratio of lesions was 2.1-fold higher in apo-I/apoA-II mice than in apoA-I mice (P<0.01). This was due to a 2.7-fold higher (P<0.001) in vivo macrophage homing in the aortic root of apoA-I/apoA-II mice. Plasma platelet-activating factor acetyl hydrolase activity was lower (P<0.01) in apoA-I/apoA-II mice, resulting in increased oxidative stress, as evidenced by the higher titer of antibodies against oxidized low density lipoprotein (P<0.01). Increased oxidative stress resulted in increased stimulation of ex vivo macrophage adhesion by apoA-I/apoA-II beta-very low density lipoprotein and decreased inhibition of beta-very low density lipoprotein-induced adhesion by HDL from apoA-I/apoA-II mice. The cellular cholesterol efflux capacity of HDL from apoA-I/apoA-II mice was very similar to that of apoA-I mice. Thus, the Arg123-Tyr166 central domain of apoA-I is critical for reducing oxidative stress, macrophage homing, and early atherosclerosis in apoE knockout mice independent of its role in HDL production and cholesterol efflux.

Systematic review and meta-analysis of antibiotic therapy for bone and joint infections

We set out to evaluate the clinical efficacy of individual antibiotic agents for bone and joint infections in adults. Published and unpublished controlled trials reported between 1966 and 2000 were reviewed to determine if they involved random or quasi-random allocation to systemically administered antimicrobials or local antibiotic therapy for osteomyelitis and septic arthritis. Quiescence of infection after 1 year of follow-up was defined as the primary outcome measure. 22 trials containing 927 patients were eligible for final analysis. Varying proportions of the entire study population could be evaluated with respect to primary and secondary endpoints. Methodological quality was poor among most studies, and interpretability of results was further limited by small sample sizes, missing descriptions of patient populations and disease characteristics, and the frequent application of concomitant antibiotics. A trend towards improved, long-lasting infection control was observed in favour of a rifampicin-ciprofloxacin combination versus ciprofloxacin monotherapy for the treatment of staphylococcal infections related to orthopaedic devices (absolute risk difference [ARD] 28-9%; 95% CI -0.7 to 54.4%). Obviously unbalanced comparative studies showed some benefit of ticarcillin for bone infections caused by Pseudomonas species. No significant differences in therapeutic efficacy were found among trials comparing oral fluoroquinolones with intravenous beta-lactam drugs for both end-of-treatment (OR 0.8; 0.5 to 1.4) and long-term results (OR 1.3; 0.8 to 2.1). A variety of drugs was used as controls, thereby leading to inconsistent findings of drug-related side effects. Only one randomised trial was suitable to investigate the impact of polymethylmethacrylate gentamicin bead chains compared with parenteral antibiotics for skeletal infections, although this study was biased by patients receiving both combined local and systemic antibiotic therapy. Whereas intention-to-treat evaluation suggested a therapeutic advantage of systemic over local therapy, this trend diminished in the per-protocol analysis (1-year follow-up ARD -2.3;-17.5 to 10.8%). There exists little high-quality evidence on antibiotic therapy for osteomyelitis and septic arthritis. The observed heterogeneity among patient populations and medical and surgical treatment concepts preclude reliable inferences from the available data.

N-linked glycosylation of macrophage-derived PAF-AH is a major determinant of enzyme association with plasma HDL

Human plasma PAF-AH (platelet-activating factor-acetylhydrolase) is a Ca(2)+-independent phospholipase A2 of hematopoietic origin associated with LDL and HDL; it degrades PAF and oxidizes phospholipids. We show that human macrophages synthesize PAF-AH as a premedial Golgi precursor containing high mannose N-linked glycans. Secreted PAF-AH possesses a molecular mass of approximately 55 kDa and contains mature N-linked glycans. Secreted PAF-AH activity (90 +/- 4% of the total) bound to a wheat germ lectin column and could be eluted with N-acetylglucosamine, whereas digestion with N-acetylneuraminidase II completely abolished enzyme absorption. Tunicamycin significantly reduced cell-associated PAF-AH activity and inhibited enzyme secretion; but it did not alter the ratio of secreted to cell-associated enzyme (1.8 at 6 h and 3.1 at 24 h), suggesting that glycosylation is not essential for PAF-AH secretion. Digestion of cell-associated PAF-AH or secreted PAF-AH with peptide N-glycosidase F affected neither catalytic activity nor its resistance to proteolysis with trypsin or proteinase K; in addition, it did not affect PAF-AH association with LDL, but significantly increased its association with HDL. We suggest that macrophage-derived PAF-AH contains heterogeneous asparagine-conjugated sugar chain(s) involving sialic acid, which hinders its association with HDL but does not influence the secretion, catalytic activity, or resistance of PAF-AH to proteases.

Shed L-selectin (sCD62L) load in trauma patients

BACKGROUND

Low circulating plasma concentrations of the leukocyte adhesion molecule L-selectin (sCD62L) were found to be associated with an increased risk for subsequent lung failure and case fatality after severe trauma. The objective of this study was to determine the robustness of soluble L-selectin, correcting for a broad spectrum of physiological variables.

METHODS

Patients with suspected multiple and/or trunk injuries were enrolled into this study over a 1-year period. Plasma samples were obtained on hospital presentation, and circulating soluble L-selectin was measured with a commercially available ELISA kit. Study records comprised all relevant clinical and laboratory data. Thirty-day survival rate, subsequent acute lung failure, and nosocomial pneumonia were defined as study endpoints. Statistical analysis was performed using multivariate logistic regression models.

RESULTS

Seventy patients with a mean age of 35.51 years (range, 10-87 years) and a mean ISS score of 36.61 (95% CI, 31.08-42.14) entered the study. Eleven patients died, leading to an attributable mortality of 15.70%. L-Selectin levels did not differ between survivors and nonsurvivors. Five patients progressed to acute lung injury, whereas 11 patients developed hospital-acquired pneumonia. Lower L-selectin levels indicated patients at risk for lung injury with a relative odds estimated at 4.43 (P = 0.017). Statistical significance diminished in the multivariate model. In contrast, plasma concentrations of circulating sCD62L were significantly decreased in patients developing nosocomial pneumonia (P = 0.023), with a twofold increased relative odds (OR, 1.96; 95% CI, 0.51-7.50). No effect modification was observed by the included covariables.

CONCLUSIONS

The results of this study highlight the independent predictive value of initially decreased soluble L-selectin levels for the identification of patients susceptible to subsequent respiratory complications after severe trauma.

Oxidized low density lipoproteins downregulate LPS-induced platelet-activating factor receptor expression in human monocyte-derived macrophages: implications for LPS-induced nuclear factor-kappaB binding activity

Monocytes/macrophages play a key role in atherogenesis due to their inflammatory properties including formation of lipid mediators such as platelet-activating-factor (PAF). We investigated the effect of oxidized low-density lipoprotein (oxLDL) on lipopolysaccharide (LPS)-induced PAF receptor (PAF-R) expression in human macrophages and the implication of the nuclear factor (NF)-kappaB in this regulation. LPS-treatment (1 microg.mL(-1)) of macrophages increased PAF binding and PAF-R mRNA expression by 56% (P < 0.05) and twofold (P < 0.01), respectively. In contrast, highly oxidized low-density lipoprotein [ox24hLDL; 100 microg.mL(-1); thiobarbituric acid reacting substances: 31 +/- 3 nmol equiv. malondialdehyde (MDA).mg protein LDL-1] diminished PAF-R expression (-69%; P < 0.05) and mRNA level (- 45%; P < 0.01). LPS pretreatment induced the activated form of p65 in the nuclear compartment of macrophages (detected by Western blotting) and NF-kappaB binding activity (by electrophoretic mobility shift assay). Treatment of macrophages with ox24hLDL suppressed the LPS-induced binding of NF-kappaB to DNA. In addition, treatment of macrophages with lysophosphatidylcholine (2 and 10 microM), a major component of oxLDL, inhibited the LPS-induced NF-kappaB binding to DNA and reduced PAF binding by 30 and 70%, respectively. In conclusion, oxLDL may downregulate PAF-R expression in human macrophages by inhibiting LPS-induced NF-kappaB binding to DNA.

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.

Adenovirus-Mediated Gene Transfer of Human Platelet-Activating Factor–Acetylhydrolase Prevents Injury-Induced Neointima Formation and Reduces Spontaneous Atherosclerosis in Apolipoprotein E–Deficient Mice

Background —Atherosclerosis is characterized by an early inflammatory response involving proinflammatory mediators such as platelet-activating factor (PAF)-like phospholipids, which are inactivated by PAF-acetylhydrolase (PAF-AH). The effect of adenovirus-mediated expression of PAF-AH on injury-induced neointima formation and spontaneous atherosclerosis was studied in apolipoprotein E–deficient mice.

Methods and Results —Intravenous administration of an adenovirus (5×10 8 plaque-forming units) directing liver-specific expression of human PAF-AH resulted in a 3.5-fold increase of plasma PAF-AH activity at day 7 ( P <0.001); this was associated with a 2.4- and 2.3-fold decrease in malondialdehyde-modified LDL autoantibodies and the lysophosphatidylcholine/phosphatidylcholine ratio, respectively ( P <0.001 for both). Non-HDL and HDL cholesterol levels in PAF-AH –treated mice were similar to those of control virus-treated mice. Seven days after virus injection, endothelial denudation of the common left carotid artery was induced with a guidewire. Neointima formation was assessed 18 days later. PAF-AH gene transfer reduced oxidized lipoproteins by 82% ( P <0.001), macrophages by 69% ( P =0.006), and smooth muscle cells by 84% ( P =0.002) in the arterial wall. This resulted in a 77% reduction ( P <0.001) of neointimal area. Six weeks after adenovirus-mediated gene transfer, spontaneous atherosclerotic lesions in the aortic root were analyzed. PAF-AH gene transfer reduced atherosclerotic lesions by 42% ( P =0.02) in male mice, whereas a nonsignificant 14% reduction was observed in female mice. Basal and PAF-AH activity after gene transfer were higher in male mice than in female mice ( P =0.01 and P =0.04, respectively).

Conclusions —Gene transfer of PAF-AH inhibited injury-induced neointima formation and spontaneous atherosclerosis in apolipoprotein E–deficient mice. Our data indicate that PAF-AH, by reducing oxidized lipoprotein accumulation, is a potent protective enzyme against atherosclerosis.

[Challenge of evidence-based medicine: sense and non-sense of diagnostic tests in gynecology]

Evidence-based medicine is the synthesis of internal evidence (experience) and best external evidence (literature) aiming to solve a particular clinical problem. This paper gives an overview on different tools to appraise rationales and results of diagnostic tests such as CA-125 monitoring in patients with ovarian cancer.