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Role of transesophageal echocardiography in the diagnosis and management of traumatic aortic disruption.

BACKGROUND: Traumatic disruption of the aorta (TDA) is a life-threatening injury that requires rapid diagnosis and treatment. Emergency aortography, which is the current standard diagnostic imaging modality, is invasive, time-consuming, and difficult to perform in hemodynamically unstable patients with multiple trauma. We performed transesophageal echocardiography (TEE) in patients with suspected TDA to determine the diagnostic accuracy and impact on patient management of this alternative, portable imaging modality. METHODS AND RESULTS: Thirty-two consecutive trauma patients (mean age, 40 +/- 16 years) with suspected TDA (violent deceleration accident and mediastinum > 8 cm on admission chest x-ray) prospectively underwent a TEE examination in the emergency room. Findings during TEE were compared with those encountered during aortography, surgery, or necropsy. Two subsets of traumatic aortic injuries with distinct echocardiographic signs were observed: (1) subadventitial TDA (n = 10) and (2) traumatic intimal tears (n = 3). Eighteen patients had normal TEE confirmed by aortography. One 2-mm medial tear was missed by TEE (necropsy). The sensitivity and specificity of TEE for the diagnosis of subadventitial TDA were 91% and 100%, respectively. Patients with subadventitial TDA were taken to surgery immediately, whereas patients with intimal aortic tears were treated conservatively. Eighteen patients (mean age, 57 +/- 15 years) with confirmed acute aortic dissection involving the aortic isthmus were also included to establish the echocardiographic differential diagnostic criteria between this entity and TDA. CONCLUSIONS: TEE should be considered the first-line imaging modality for the evaluation of trauma patients with suspected injuries of the thoracic aorta because of its portability, safety, diagnostic accuracy, and potential impact on patient management.

Adult↗

Evaluation of a portable recording device (Somnocheck) for use in patients with suspected obstructive sleep apnoea.

BACKGROUND: Portable recording devices for the diagnosis of obstructive sleep apnoea (OSA) should be carefully evaluated before being used on a routine basis in out-patients. OBJECTIVE: This study was designed to evaluate the diagnostic accuracy of the new portable recording device, Somnocheck (SC). METHODS: Nocturnal polysomnographies (PSG) and SC recordings were performed simultaneously in the sleep laboratory in 51 patients with suspected OSA, and were analysed manually by a blinded investigator. RESULTS: The apnoea/hypopnoea index (AHI) obtained by manual SC analysis correlated closely with that obtained by PSG (r = 0.98), but the correlation with AHI obtained by automatic SC analysis was markedly lower (r = 0.83). When an AHI > or =10 was defined as indicative of OSA, the sensitivity of manual SC analysis was 0.97 and its specificity 1.00. The sensitivity of automatic analysis was 0.83 and its specificity 0.95. CONCLUSIONS: In this experimental setting, the SC showed a very high diagnostic accuracy for the diagnosis of OSA and was able to define its severity precisely. The diagnostic accuracy of manual analysis was found to be superior to that of automatic analysis. Considering the results of this technical evaluation, the SC may also be expected to work reliably when it is used in an ambulatory setting.

Adult↗

A novel continuous subcutaneous lactate monitoring system.

A novel continuous lactate monitoring system has been developed modifying the GlucoDay portable medical device (A. Menarini Diagnostics), already present in the European market, and used to continuously measure glucose levels. Lactate oxidase based biosensors have been developed immobilising the enzyme on nylon net and placing it on a Pt electrode. The biosensor was connected to the portable device provided with a micro-pump and coupled to a microdialysis system. It is capable to record subcutaneous lactate every 3 min. In vitro analytical results confirmed that the sensors respond linearly in the interval of concentration between 0.1 and 10 mmol/L, covering the whole physiological range. During prolonged monitoring periods, the response of the biosensors remained stable, showing a limited drift of 8%, within 60 h. Stability tests are still on route. However, preliminary results have shown a shelf life of about 10 months. In vivo experiments performed on healthy rabbits have demonstrated the good accuracy and reproducibility of the system. A correlation coefficient equal to 0.9547 (N=80) was found, which represents a good correlation between the GlucoDay and the laboratory reference analyser. A 16 h in vivo monitoring on a healthy volunteer has been also performed.

Animals↗

Physician utilization of a portable computed tomography scanner in the intensive care unit.

OBJECTIVE: To determine the utilization of a portable computed tomography (CT) scanner for critically ill adult patients in an intensive care unit (ICU). DESIGN: Survey study and retrospective review. SUBJECTS: Critical care attending staff and fellows and neurosurgery residents. SETTING: A university hospital and Level I trauma center with a multitrauma ICU, a neurotrauma ICU, and a neurosurgical ICU. INTERVENTIONS: We surveyed all physicians who ordered portable CT scans from December 1996 through June 1998. Ordering physicians included critical care attending staff and fellows (anesthesiology, surgery, internal medicine) and neurosurgery residents. Physicians who no longer worked at the institution were contacted by mail or fax. Radiology records were reviewed to determine the actual number and type of scans performed. MEASUREMENTS AND MAIN RESULTS: The survey response was 100%. Most physicians reported ordering portable head CT scans (97%), followed by chest CT (88%), abdominal CT (78%), and pelvic CT (34%) scans. Analysis of the actual number of scans performed correlated with these reports (511 head, 115 chest, 88 abdomen, and 87 pelvis). The indication for portable CT scans (as opposed to a "fixed" or "stationary" scans) cited most often was patient severity of illness (77%). Patients on extracorporeal support (93%), those with cardiovascular instability (70%), followed by those with respiratory instability (57%) and neurologic instability (40%) were deemed too ill to transport. If the portable CT scanner was unavailable, however, most physicians (67%) ordered a fixed helical CT scan and the patient was transported to the radiology suite, regardless of medical condition. CONCLUSIONS: Access to a portable CT scanner impacts the physician ordering patterns for ICU patients. We found that 100% of surveyed physicians used the portable CT scanner for critically ill patients when the patient was unstable. If the diagnostic study was deemed medically necessary, and the portable scanner was unavailable, most surveyed physicians ordered a "fixed" helical scan and the patient was transported by an experienced transport team for the study. The portable CT offered an alternative and potentially safer means of obtaining diagnostic studies.

Attitude of Health Personnel↗

Screening for high-grade carotid stenosis using a portable ultrasonography instrument.

BACKGROUND AND PURPOSE: We investigated the diagnostic performance of a brief Power Doppler Imaging (PDI) screening examination for carotid artery stenoses using a newly developed portable instrument. METHODS: A highly experienced sonographer screened in total 152 carotid arteries by either continuous wave (cw) Doppler (n= 50) or a lightweight (2.4 kg) portable duplex device (n= 102) in a prospective study of 76 high-risk patients. The screening protocols included either spectrum analysis and frequency shift measurement in both internal carotid arteries with cw-Doppler or determination of area and diameter ratios in transverse and longitudinal views of both carotid arteries in B-mode and with PDI, but without velocity measurement. Both protocols were evaluated against a complete routine duplex ultrasonography examination. RESULTS: According to the complete examination, stenoses were <50% in 73 of 102 (71.6%), 50-75% in 19 of 102 (18.6%), 75-95% in 7 of 102 (6.9%), and occluded in 3 of 102 (2.9%) arteries (PDI cohort), and <50% in 39 of 50 (78%), 50-75% in 8 of 50 (16%), 75-95% in 2 of 50 (4%), and occluded in 1 of 50 (2%) artery (cw-Doppler cohort). Mean screening time was 8.8 +/- 2.5 minute (PDI) and 9.4 +/- 2.6 minute (cw-Doppler). For stenoses >75%, A(z) values (area under the receiver operating characteristics curve) were 0.897 for area ratios, 0.843 for diameter ratios (PDI protocol) and 1.0 for the cw-Doppler protocol. CONCLUSIONS: The diagnostic performance of the cw-Doppler protocol was superior to the PDI protocol. Nevertheless, both protocols appear suitable as inexpensive screening strategies to identify subjects with >75% stenosis measured by carotid Doppler ultrasound. However, these preliminary data need further verification.

Aged↗

Better by design: the humanising technology project.

This reports on a design initiative that is helping to translate some of the latest developments into commercial reality. Biosensor technology represents an immense opportunity to revolutionise diagnostics. Under this initiative, one company has developed a portable hand-held platform for rapid measurment of multiple diagnostic parameters.

Biosensing Techniques↗

Potential dosing errors using portable prothrombin time monitoring devices.

Portable prothrombin time (PT) monitors facilitate the control of warfarin therapy. Few studies have compared the influence of using different monitors on dosage decisions. We determined the comparability of data generated by two portable PT monitors, Coaguchek S, (Roche Diagnostics Boehringer-Mannheim) and Hemochron Jr (International Technidyne Corporation Ltd.), with that of a reference laboratory. Simultaneous International Normalized Ratio (INR) measurements (portable monitor and laboratory) were performed in 193 consecutive patients receiving warfarin for at least 3 months. Agreement of measurements was assessed by both regression analysis and influence on dosage decisions in accordance with pre-defined criteria. The Coaguchek S versus laboratory INR regression line (n = 111; r2 = 0.88; P < 0.001) was close to the line of identity, while that of the Hemochron Jr (n = 82; r2 = 0.61; P < 0.001) was not. The overall proportion of dual INR measurements that fulfilled the clinical criteria of agreement was 90% for the Coaguchek S compared with 62% for the Hemochron Jr (P < 0.0001). For laboratory INRs 2.0-2.5, 2.6-4.0 and > 4.0, the proportions of portable measurements that satisfied the clinical criteria for the Coaguchek S versus the Hemochron Jr were 96 versus 63% (P < 0.001), 81 versus 45% (P < 0.04), and 67 versus 17% (P < 0.85), respectively. Warfarin dosing based solely on the portable devices would have resulted in unjustified dose increments in 22% of the patients with the Hemochron Jr device compared with 8% with the Coaguchek S monitor (chi2 = 4.43; P = 0.035). The Coaguchek S monitor provides measurements for INR values within the therapeutic range that agree well with the standard laboratory. The Hemochron Jr measurements result in different dosage adjustments even within the therapeutic range, but especially for INR values > 4.0. For both monitors, agreement of INR measurements with the standard decreases with increasing INR values.

Adult↗

[The validation of a portable 3-channel recording system (Oxyflow, Edentec) for the diagnosis of the sleep apnea syndrome].

OBJECTIVE: To evaluate the usefulness of a portable recording device (Oxyflow, EdenTec) to measure oronasal airflow, oxygen saturation and arterial pulse for diagnosing sleep apnea syndrome (SAS) using conventional polysomnography as the gold standard. METHODS: Sixty-two subjects suspected of having SAS were studied prospectively by simultaneously recording conventional polysomnography and Oxyflow data in the sleep laboratory. Two different investigators, blinded to each other's findings, interpreted the data from each method. The apnea-hypopnea index (AHI) cut-off points used were?? 10, 15 and 30. The sensitivity, specificity, positive predictive value and negative predictive value of the Oxyflow indices for each AHI cut-off point were calculated. Both computer-generated and manually collected data from the Oxyflow device were analyzed. Manual readings were recorded by two independent investigators and interobserver agreement was calculated. The usefulness of both automatic and manual analyses for SAS diagnosis was assessed using receiver operating characteristic curves (ROC). RESULTS: Fifty-eight (93.5%) men and 4 (6.5%) women with a mean age (+/- SD) of 53 +/- 11 years (29-73) were enrolled. An AHI > or = 10 was observed in 58% of the patients and mean AHI was 25 +/- 28 (0-125). The index of respiratory disturbance per hour of analysis with desaturation events > or = 4% (RDI4%) was the parameter with the largest area under the ROC curve (0.90 for AHI > or = 10; 0.94 for AHI > or = 15 and 0.96 for AHI > or 30). Manual reading was practical and reproducible (agreement 0.93, kappa coefficient 0.82) but its efficiency was no greater than that of automatic analysis. CONCLUSIONS: The Oxyflow device may be a useful diagnostic tool for SAS. Its portability and simplicity makes it potentially useful for in-home studies.

Adult↗

Yield of transcranial Doppler in acute cerebral ischemia.

BACKGROUND AND PURPOSE: The objective of this study was to evaluate the yield of emergent transcranial Doppler (TCD) for the evaluation of acute cerebral ischemia. METHODS: We performed urgent bedside non-contrast-enhanced TCD in patients with acute cerebral ischemia before or immediately after baseline CT scanning. A fast-track scanning protocol (</=15 minutes) and detailed diagnostic criteria were developed for portable single-channel TCD testing. TCD results were compared with angiography. RESULTS: Of 130 consecutive patients studied, 36 were eligible for thrombolytic therapy; 46 with ischemic strokes and 48 with transient ischemic attacks were not eligible for thrombolysis. TCD identified occlusions in 69% of thrombolysis-eligible patients, compared with 24% and 0% of patients with strokes and transient ischemic attacks, respectively, not eligible for thrombolysis (P<0.01). Stenosis was present in 17%, 33%, and 35%, and normal vessels were found in 14%, 43%, and 65% in the respective patient subgroups. TCD also identified abnormal pulsatility of flow (12 patients), abnormal flow velocities (12), microembolic signals (5), or early recanalization (5) (34 of 130; 26%). In 65% of all patients, TCD was compared with angiography (digital subtraction angiography, MR angiography, or CT angiography). Despite a 15% rate of absent temporal windows, TCD had 88% accuracy for abnormal (occlusion and stenosis) versus normal vessels: sensitivity 87.5%, specificity 88.6%, positive predictive value 87. 5%, and negative predictive value 88.6%. CONCLUSIONS: A proximal occlusion on TCD was found in 69% of thrombolysis-eligible patients. In 26% of all patients, TCD provided further relevant information that, in addition to angiography, helped to refine the severity of a stenosis and determine stroke pathogenesis. Emergent TCD is both sensitive and specific in determining arterial occlusion and stenosis in acute cerebral ischemia.

Acute Disease↗

Diagnostic and therapeutic vitrectomy for endophthalmitis.

The introduction of a compact portable vitreous suction cutter enables the aspiration and resection of infected ocular tissues for diagnostic and therapeutic purposes. Four cases of postoperative bacterial endophthalmitis are presented in which mechanical anterior vitrectomy was performed in addition to conventional antimicrobial therapy. Three of these eyes were saved and 2 retained the possibility of useful vision. A rationale for the aggressive managements of endophthalmitis is presented.

Aged↗

Accuracy of a portable prothrombin time monitor (Coagucheck) in patients on chronic oral anticoagulant therapy: a prospective multicenter study.

A portable prothrombin time (PT) monitor allows patients on oral anticoagulant therapy (OAT) to measure their PT at home. The purpose of the study was to evaluate the accuracy and precision of a portable PT monitor (Coagucheck, Roche Diagnostics, Mannheim, Germany) as compared with laboratory methods. The prospective study was conducted in four centers of the Italian Federation of Anticoagulation Clinics. A one-month instruction phase was followed by a six-month surveillance phase. Seventy-eight subjects on stable OAT (48 men, 30 women, age range: 18-75) were selected on a volunteer basis. Dual measurements of INR values were performed in each subject both from finger capillary blood by the monitor and from venous blood by the Anticoagulation Clinic laboratory in three instruction sessions. The mean difference (bias) of the monitor INR results when compared with the average of laboratory INR and monitor INR results was -0.025 (limits of agreement-LA: -0.84/+0.81 INR units). The mean bias was -0.0675 (LA: -0.37/+0.23), +0.018 (LA: -0.39/+0.35), and +0.039 (LA: -0.49/+0.55), respectively, for INR values lower than 2.0, between 2.0 and 3.0, and greater than 3.0. The overall precision coefficient of monitor INR was 0.370, while it was 0.23, 0.46, 0.29, and 0.21, respectively, in Centers 1, 2, 3, and 4. The overall variation coefficient was 6.5% while it was 3.7%, 8.5%, 4.7%, and 4.9%, respectively, in Centers 1, 2, 3, and 4. Coagucheck has an acceptable level of accuracy for INR values in the range between 2.0 and 3.0. A wide variation in monitor performance was found among centers.

Administration, Oral↗

Measurements of attention deficits and impulsivity: a Swedish study of the Gordon Diagnostic System.

The Gordon Diagnostic System (GDS) is a portable easily operated computerized tool developed to measure impulse control, attention and vigilance. In 1988, it was standardized for use among American children. The aim of this study was to evaluate the GDS for use among Swedish children. A clinical sample of 71 Swedish children, mean age 10.5 y, fulfilling the ADHD criteria according to the DSM-IV was compared with a control sample of 88 children, mean age 10.2-y, with no known psychiatric diagnosis. The clinical sample showed lower GDS scores in all age groups, with some exceptions. The GDS scores were not associated with gender, but strongly associated with age, especially in the control sample. The accuracy of the GDS referring a specific child to either of the samples was, as expected, not impressive. With respect to the practical usefulness, the GDS was well accepted by the children and parents in both samples. The findings in age variation and when comparing children with ADHD and controls are in agreement with results from other studies.

Adolescent↗

Neonatal intracerebellar hemorrhage: detection by real-time ultrasound.

Two cases of primary intracerebellar hemorrhage in premature neonates in which diagnosis was established primarily by real-time ultrasound are presented. It is concluded that real-time, portable ultrasound should be the diagnostic method of choice in evaluating the brain in infants on multiple life-support systems.

Cerebellar Diseases↗

A consensus approach to diagnosing coronary artery disease based on clinical and exercise test data.

OBJECTIVE: To demonstrate that a consensus approach for combining prediction equations based on clinical and exercise test variables derived from different populations can stratify patients referred for possible coronary artery disease (CAD) into low-, intermediate-, and high-risk groups. DESIGN: Retrospective analysis of consecutive patients with complete data from exercise testing and coronary angiography referred for evaluation of possible CAD. After derivation of a logistic equation in our own training set of patients, this equation, along with two other equations developed independently by other investigators, was validated in a test set. The validation strategy for the consensus approach included the following: (1) calculation of probability scores for each patient using each logistic equation independently; (2) determination of probability thresholds in the training set to divide the patients into three groups-low risk (prevalence CAD <5%), intermediate risk (5 to 70%), and high risk (>70% prevalence of CAD); (3) using agreement among at least two of three of the prediction equations to generate "consensus" for each patient; and (4) application of the consensus approach thresholds to the test set of patients. SETTINGS: Two university-affiliated Veteran's Affairs medical centers. PATIENTS: We studied 718 consecutive men between 1985 and 1995 who had coronary angiography within 3 months of an exercise treadmill test for suspected CAD. The population was randomly divided into a training set of 429 patients and a test set of 289 patients. Patients with previous myocardial infarction or coronary artery bypass surgery, valvular heart disease, left bundle branch block, or any Q waves present on their resting ECG were excluded from the study. MEASUREMENTS: Recording of clinical and exercise test data along with visual interpretation of the ECG recordings on standardized forms and abstraction of visually interpreted angiographic data from clinical catheterization reports. RESULTS: We demonstrated that by using simple clinical and exercise test variables, we could improve on the standard use of ECG criteria during exercise testing for diagnosing CAD. Using the consensus approach divided the test set into populations with low, intermediate, and high risk for CAD. Since the patients in the intermediate group would be sent for further testing and would eventually be correctly classified, the sensitivity of the consensus approach is 94% and the specificity is 92%. The consensus approach controls for varying disease prevalence, missing data, inconsistency in variable definition, and varying angiographic criterion for stenosis severity. The percent of correct diagnoses increased from the 67% for standard exercise ECG analysis and from the 80% for multivariable predictive equations alone to >90% correct diagnoses for the consensus approach. CONCLUSIONS: The consensus approach has made population-specific logistic regression equations portable to other populations. Excellent diagnostic characteristics can be obtained using simple data and measurements. The consensus approach is best applied utilizing a programmable calculator or a computer program to simplify the process of calculating the probability of CAD using the three equations.

Coronary Angiography↗

Portable CT: assessing thoracic disease in the intensive care unit.

OBJECTIVE: The objective of this study was to assess the usefulness of a portable CT scanner to evaluate and treat thoracic disease in patients in the intensive care unit. MATERIALS AND METHODS: Fourteen patients who were being treated in the intensive care unit underwent 20 portable CT scans. Twice a CT scan was obtained to guide an interventional chest procedure. The remaining 18 scans were assessed for findings not evident on portable chest radiography and for findings that altered treatment. Image quality was judged in comparison with fixed CT scans. RESULTS: Unsuspected abnormalities, most relating to the pleura or chest wall, were found in 13 of the 17 available portable CT scans. Treatment was affected in four (25%) of the 16 cases in which medical records were available for review. Two interventional procedures were performed successfully using portable CT guidance. Scan quality was judged to be comparable with that of fixed CT for mediastinal windows and somewhat inferior for lung windows. CONCLUSION: Portable CT gives images of diagnostic quality and allows confident guidance during interventional procedures in critically ill patients who therefore need not leave the intensive care unit environment.

Adult↗

Assessment of patient capability to self-adjust oral anticoagulant dose: a multicenter study on home use of portable prothrombin time monitor (COAGUCHECK).

BACKGROUND AND OBJECTIVES: Self-testing and self-monitoring with portable prothrombin time (PT) monitors has been shown to be feasible and safe. However the ability of patients on chronic oral anticoagulant therapy (OAT) to self-adjust their dose without specific training has never been properly evaluated. The aims of this study were to evaluate: 1) the ability of patients on chronic OAT to self-adjust their dose without specific training; 2) the integration of a portable PT monitor (Coagucheck, Roche Diagnostics, Germany) for home use into routine patient care in anticoagulation clinics. DESIGN AND METHODS: A nested case-control study was conducted in four centers of the Italian Federation of Anticoagulation Clinics (FCSA). Patients (n=78) on stable OAT for at least 6 months (cases: 47 men, 31 women, age range: 18-75 years) were enrolled on a volunteer basis after passing an Abbreviated Mental Test and providing informed consent. After three instruction sessions on the use of Coaguchek, subjects performed the PT test at home, communicated the INR results to the Center and suggested the dose adjustment and date for next control as they thought appropriate. However, they were requested to follow the prescription made by the Center. Controls (78 subjects) matched by age (+/- 5 years), sex and therapeutic range with the cases, were selected from among those who attended the anticoagulation clinics and managed by usual care. RESULTS: When compared with the dose prescribed by the Clinic, the dose suggested by warfarin and acenocoumarol users was equal to or within +/- 6% of the mean weekly dose in 80% and 82% of suggestions, respectively. Time spent in the therapeutic range during the study was the same (80%) for cases and controls. INTERPRETATION AND CONCLUSIONS: Selected patients on chronic anticoagulant therapy can acquire a satisfactory ability for self-adjustment of OAT dose without specific training.

Acenocoumarol↗

[Evaluation of a portable ultrasound device immediately after spiral computed tomography].

AIM: Portable ultrasound devices are an established diagnostic tool. They are frequently used in trauma and emergency wards. Multidetector computed tomography (MD-CT) represents the standard imaging method for many diagnostic questions. In some patients, however, there are findings on CT which remain unspecific. In these cases, a complementary ultrasound (US) examination may help to obtain a specific diagnosis. Aim of this study is the evaluation of a portable US device immediately after MD-CT for further work-up of unclear lesions. METHODS: 257 MD-CT examinations were performed during a 3-week period. A portable US device (LogiqBook, GE Medical Systems, Solingen, Deutschland) was used when a lesion found at MD-CT remained unclear. Time intervals between CT and US as well as US examination times were registered. RESULTS: US was used in 23 of 257 CT examinations (8.9 %), but 3 of these examinations had to be terminated due to unfavourable US conditions. Thus, there remained 19 questions regarding parenchymal lesions in the liver (n = 13), kidney (n = 1) or suprarenal gland (n = 2). Pleural empyema was suspected in the 4 remaining patients. In all of the 20 patients, US helped to narrow down the differential diagnosis of MD-CT results. The mean time span between CT and US was 2.5 min, and the mean US examination time was 6.5 min. CONCLUSION: Portable US immediately after MD-CT helps to narrow down the differential diagnosis of hepatic and pleural lesions with minimal additional effort in time and organization.

Adrenal Gland Diseases↗