The PartnerWeb Project: a component-based approach to enterprise-wide information integration and dissemination.

A component-based health information resource, delivered on an intranet and the Internet, utilizing World Wide Web (WWW) technology, has been built to meet the needs of a large integrated delivery network (IDN). Called PartnerWeb, this resource is intended to provide a variety of health care and reference information to both practitioners and consumers/patients. The initial target audience has been providers. Content management for the numerous departments, divisions, and other organizational entities within the IDN is accomplished by a distributed authoring and editing environment. Structured entry using a set of form tools into databases facilitates consistency of information presentation, while empowering designated authors and editors in the various entities to be responsible for their own materials, but not requiring them to be technically skilled. Each form tool manages an encapsulated component. The output of each component can be a dynamically generated display on WWW platforms, or an appropriate interface to other presentation environments. The PartnerWeb project lays the foundation for both an internal and external communication infrastructure for the enterprise that can facilitate information dissemination.

Digital storage of echocardiograms offers superior image quality to analog storage, even with 20:1 digital compression: results of the Digital Echo Record Access Study.

A large interobserver and intraobserver variability study was performed comparing both digitally compressed and uncompressed echocardiographic images with the same images recorded onto super-VHS video-cassette tape (the current standard). In a blinded, randomized fashion, 179 observers scored the diagnostic and image quality of 20 pairs of echocardiographic loops representing various pathologic conditions. Overall, the digital images were preferred to the S-VHS images both for image quality and diagnostic content (p < 0.0001) regardless of the background or experience level of the observer. Furthermore, uncompressed digital images and those compressed by the Joint Photographic Experts Group (JPEG) algorithm at ratios of 20:1 were judged equivalent. These findings show that digital compression may be used routinely in echocardiography, resulting in improved image and diagnostic quality over present standards.

Digital compression of echocardiograms: impact on quantitative interpretation of color Doppler velocity.

To test the impact of Joint Photographic Expert Group (JPEG) compression on the quantitative data encoded in color Doppler echocardiographic images, digital images from transesophageal echocardiography and an in vitro model of proximal flow convergence were analyzed before and after JPEG compression with compression ratios (CRs) as high as 65:1. Even at the highest CRs, greater than 95% of the pixels were categorized correctly as representing structure (gray scale) and greater than 98% were categorized correctly as representing velocity (color) data. Furthermore, the velocities and flows recovered from the compressed images agreed well (r = 0.998 [velocities] and r = 0.998 [flows] for CR = 7:1, falling to r = 0.881 [velocities] and r = 0.930 [flows] at CR = 65:1; p < 0.001 for the linear trend with CR). There was similarly little shift in the location of the red-blue aliasing contour, rising from an error of 0.05 +/- 0.19 (mean +/- SD) mm at CR = 7:1 to a maximum error of 0.11 +/- 0.36 mm at CR = 44:1. Thus JPEG compression has little impact on the quantitative velocity data encoded within color Doppler echocardiograms, which should allow widespread acceptance of digital transmission and storage.

Facilitating physician referrals on the World Wide Web: representation and appropriate utilization of clinical expertise.

In highly integrated and increasingly complex health care systems, the identification and proper utilization of clinical staff expertise are key factors for efficiently delivering high quality patient care. To achieve these capabilities on an enterprise-wide scale, we have embarked on a multi-phased project to develop World Wide Web (WWW)-based physician referral capabilities for two large teaching hospitals. Currently, users may search for information concerning the education, training, board certifications, and self-designated clinical interests of staff members. Address, phone number, email address, and a photo are also presented. Our experience indicates that institutional changes are required to successfully deploy and maintain online physician referral services and that accurate and equitable representation of clinical expertise and the incorporation of referral guidelines require an incremental introduction of a carefully planned program that addresses the needs of clinicians, administrators, and health care policy-makers.

JPEG compression of digital echocardiographic images: impact on image quality.

Routine echocardiograms are not handled digitally because of enormous storage needs. Image compression techniques can reduce memory requirements, but the impact on diagnostic content is unknown. We studied the effect of an internationally accepted compression algorithm called Joint Photographic Experts Group (JPEG) on digital echocardiographic images. Diagnostic and image quality of JPEG compressed, two-dimensional echocardiograms at ratios ranging from 4:1 to 40:1 was compared with that of uncompressed images both subjectively by a blinded expert panel (540 observations) and objectively by quantitative image-processing parameters (180 images). Accuracy of 432 measurements performed on compressed M-mode and spectral Doppler tracings was determined. Simultaneously acquired videotaped images and their never-compressed digital counterparts were compared quantitatively for image fidelity. This study demonstrates that the JPEG compression algorithm produces little degradation of echocardiographic images at compression ratios of at least 20:1, with less measured distortion than is produced by videotape recording. With JPEG, digital storage and retrieval in routine echocardiography are feasible.

Which physical factors determine tricuspid regurgitation jet area in the clinical setting?

The visual assessment of jet area has become the most common method used in daily clinic practice to evaluate valvular regurgitation. Despite the high prevalence of tricuspid regurgitation, however, few studies have systematically compared TR jet areas with a quantitative standard. To evaluate this, 40 patients in sinus rhythm with tricuspid regurgitation were analyzed: 16 with centrally directed free jets and 24 with impinging wall jets. The size of the maximal planimetered color jet area (cm2) was compared with parameters derived using the pulsed Doppler 2-dimensional echocardiographic method: regurgitant fraction and the flow convergence method (peak flow rate, effective regurgitant orifice area and momentum). Mean tricuspid regurgitant fraction averaged 33 +/- 15%, peak flow rate 76 +/- 54 cm3/s, effective regurgitant orifice area 27 +/- 21 mm2 and momentum 21,717 +/- 15,014 cm4/s2. An average of 4-chamber, and long- and short-axis areas in free jets correlated well with regurgitant fraction (r = 0.81, p < 0.001), better with peak flow rate (r = 0.94, p < 0.001), effective regurgitant orifice (r = 0.92, p < 0.001) and momentum (r = 0.94, p < 0.001). The correlation was worse, but still significant, in wall jets. For the same peak flow rate, wall jets were 75% of the size of a corresponding free jet. Jet area measurement is a good semiquantitative tool to measure tricuspid regurgitation in free jets, which correlates well with regurgitant fraction and better with new parameters available from analysis of the proximal acceleration field. In patients with eccentrically directed wall jets the correlation with planimetered jet area was worse, but still significant.

Getting best results from echocardiography in emergency situations. Indications include shock, infarction, heart failure, trauma, tamponade.

In the ICU, both transthoracic and transesophageal echocardiography can assist in the acute management of a number of different disorders. In hypotensive patients, echocardiography helps distinguish between cardiogenic shock (resulting from acute myocardial infarction), septic shock, and circulatory shock (associated with a reduction in circulating blood volume); it can also help determine whether pericardial effusion or obstruction to valvular flow is producing the hypotension and suggesting pulmonary embolus. Other roles for echocardiography include differentiating left- and right-sided heart failure, assessing the extent of pericardial disease, diagnosing disorders of the thoracic aorta, and evaluating traumatic heart disease.

How best to use echocardiography for definitive assessment. Methods of estimating valvular integrity, LV function, pulmonary pressure.

In patients with myocardial infarction, echocardiography helps predict outcome, as well as guide the selection of interventional strategies. By assessing the extent of valvular dysfunction and abnormalities in LV and RV size and function, echocardiography can help determine whether surgery is needed in patients with valvular heart disease. Both pulmonary artery pressures and LV function can be evaluated and quantified with ultrasonically derived data. Although echocardiography cannot document active infection, vegetations may appear as areas of valvular thickening. The role of echocardiography will continue to evolve as new techniques are developed.

Pheochromocytoma multisystem crisis. A surgical emergency.

Three of 27 patients treated for pheochromocytoma between 1974 and 1987 presented with pheochromocytoma multisystem crisis (PMC). This unusual presentation consists of multiple organ system failure, temperature often greater than 40 degrees C, encephalopathy, and hypertension and/or hypotension. Although urgent medical therapy achieved blood pressure control in all three patients, the other manifestations of PMC progressed rapidly in spite of alpha and even beta blockade. The first patient died during attempts to localize a septic focus. The other two patients underwent urgent adrenalectomy and had postoperative improvement in their multiple organ system failure. All three tumors were large and produced markedly elevated levels of epinephrine. In conclusion (1) PMC is an unusual presentation of pheochromocytoma; (2) its manifestations include multiple organ system failure, high fever, encephalopathy, and vascular lability; (3) it may result from increased epinephrine secretion; and (4) successful treatment of PMC demands prompt diagnosis, vigorous medical preparation, and emergency tumor removal if the patient's condition continues to deteriorate.