The HL7 Clinical Document Architecture.

Many people know of Health Level 7 (HL7) as an organization that creates health care messaging standards. Health Level 7 is also developing standards for the representation of clinical documents (such as discharge summaries and progress notes). These document standards make up the HL7 Clinical Document Architecture (CDA). The HL7 CDA Framework, release 1.0, became an ANSI-approved HL7 standard in November 2000. This article presents the approach and objectives of the CDA, along with a technical overview of the standard. The CDA is a document markup standard that specifies the structure and semantics of clinical documents. A CDA document is a defined and complete information object that can include text, images, sounds, and other multimedia content. The document can be sent inside an HL7 message and can exist independently, outside a transferring message. The first release of the standard has attempted to fill an important gap by addressing common and largely narrative clinical notes. It deliberately leaves out certain advanced and complex semantics, both to foster broad implementation and to give time for these complex semantics to be fleshed out within HL7. Being a part of the emerging HL7 version 3 family of standards, the CDA derives its semantic content from the shared HL7 Reference Information Model and is implemented in Extensible Markup Language. The HL7 mission is to develop standards that enable semantic interoperability across all platforms. The HL7 version 3 family of standards, including the CDA, are moving us closer to the realization of this vision.

Educating patients with type 2 diabetes.

The patient is the self-manager of type 2 diabetes. The role of the health care professional is to provide the knowledge, skills, and behavior change support to empower the patient to do so. Recent governmental, financial, and clinical factors influence how health care professionals perform this role. Such factors coupled with a growing body of research evidence are shaping the way diabetes self-management education is provided.

An update on HL7's XML-based document representation standards.

Many people know of HL7 as an organization that creates healthcare messaging standards. But HL7 is also developing standards for the representation of clinical documents (such as discharge summaries and consultation notes). These document standards comprise the HL7 Clinical Document Architecture (CDA). Last year we presented a high-level conceptual overview of the CDA. Since that time, CDA has entered HL7's formal ballot process (which when successful will make the CDA an ANSI-approved HL7 standard). This article delves into the technical details of the current CDA proposal. Note that due to space limitations, only a subset of CDA details can be described. Also, because the ballot process elicits considerable feedback, it is likely that the material presented here will undergo evolution prior to becoming a final standard. The most up-to-date information is available on HL7's web site (www.hl7.org).

Clinician usage patterns of a desktop radiology information display application.

We developed a system for delivering radiologic images and reports to desktop computers used for the electronic medical record (EMR). This system was used by both primary care physicians and specialists primarily in the out-patient setting. The system records all physician interactions with the application to a database. This usage information was then studied in order to understand the value and requirements of an application that could display radiology information (reports and images) on EMR workstations. In this report we describe some of the differences and similarities in usage patterns for the two physician groups. A very high percentage of physicians indicated that having image display capabilities on the workstations was very valuable.

Digraph visualization using a neural algorithm with a heuristic activation scheme.

This paper presents an activation scheme for use with Hopfield neural network algorithms that guarantees a valid solution for a particular category of problems. The technique monitors the appropriate neurons and heuristically controls their activation function. As a result it has been possible to eliminate several constraint terms from the energy function that normally would have been required to drive the network toward a valid solution. This saves time and eliminates the need for empirically determining a larger number of constants. This technique has been applied to the combinatorial optimization problem called hierarchical digraph visualization that arises in many application areas where it is necessary to visually realize the relationship between entities in complex systems. Results are presented that compare this new approach with a more traditional neural network approach as well as heuristic approaches, performance improvement in terms of the solution quality as well as execution time relative to both alternative techniques was achieved.

Image display for clinicians on medical record workstations.

Image display on electronic medical record (EMR) workstations is an important step in widespread implementation of picture archiving and communications systems (PACS). We describe a pilot project for implementing image display capability that is integrated with the EMR software, and will allow display of images on the physician's workstation. We believe this pilot will provide valuable information about usage patterns in image display needs, which will be valuable in planning further expansion of PACS in our institution.

Nutrition management for individuals with noninsulin-dependent diabetes mellitus in the 1990s: a review by the Diabetes Care and Education dietetic practice group.

Noninsulin-dependent diabetes mellitus (NIDDM), or Type II diabetes, is characterized by two primary defects: insulin resistance and insulin secretion. The two major goals of management of NIDDM are to achieve near normal metabolic control and to prevent/delay the microvascular and macrovascular complications of diabetes. Nutrition, exercise, and, if necessary, medication are the three primary treatment modalities used in NIDDM. Treatment regimens need to be individualized and developed with consideration for diabetes management goals and quality-of-life issues. Lean individuals with NIDDM should be encouraged to maintain their body weight and modify food composition and eating pattern to minimize glucose excursions. The primary treatment goal for an obese individual with NIDDM is weight loss. The process of teaching nutrition and meal planning involves developing a cooperative alliance, gathering information, setting realistic goals, intervention, and maintaining change. Nutrition intervention involves providing information in stages, beginning with "survival skill" information and progressing to in-depth information. The dietitian's responsibility is to promote continuity of learning by introducing new ideas and concepts and altering the learning environment. Dietitians can expand their role in the 1990s to that of a diabetes educator taking a leadership role to ensure that the individual with NIDDM receives comprehensive and individualized care.

Effect of temporal distribution of calories on diurnal patterns of glucose levels and insulin secretion in NIDDM.

The effect of different temporal patterns of calorie intake on plasma glucose, serum insulin, and insulin secretion rates was examined in six patients with moderately well controlled non-insulin-dependent diabetes mellitus (NIDDM). Patients were studied on three separate occasions over 26 h. Total calories and food composition (50% carbohydrate, 15% protein, and 35% fat) were kept constant, but the pattern of calorie intake was varied. In study A (similar meal size), calories were distributed as 30, 40, and 30% at breakfast, lunch, and dinner, respectively. In study B (3 snacks, 3 meals), each subject ate three meals of 20, 20, and 30% of calories for breakfast, lunch, and dinner, respectively, and three snacks, each comprising 10% of calories, presented 2.5 h after the meal. In study C (large dinner), 10% of calories were consumed at breakfast, 20% at lunch, and 70% at dinner. Glucose, insulin, and C-peptide concentrations were measured at 15- to 30-min intervals. Insulin secretion rates were calculated from C-peptide levels with individually derived C-peptide clearance parameters. The different eating patterns were associated with only modest differences in overall levels of glucose and insulin secretion. Daytime insulin secretion was lowest when most of the daily calorie intake occurred in the form of a large dinner. Overnight levels of glucose and insulin secretion rates did not differ for the three eating patterns, and the morning glucose levels were also unaffected by the pattern of calorie intake on the previous day. A morning rise of glucose of greater than 0.28 mM occurred consistently only when dinner was of moderate size (30% of total calories).(ABSTRACT TRUNCATED AT 250 WORDS)

Glyburide enhances the responsiveness of the beta-cell to glucose but does not correct the abnormal patterns of insulin secretion in noninsulin-dependent diabetes mellitus.

Eleven patients with noninsulin-dependent diabetes mellitus were studied before and after 6-10 weeks of glyburide therapy. Patients were studied during a 24-h period on a mixed diet comprising 30 Cal/kg divided into three meals. The following day a hyperglycemic clamp study was performed, with glucose levels clamped at 300 mg/dL (16.7 mmol/L) for a 3-h period. Insulin secretion rates were calculated by deconvolution of peripheral C-peptide concentrations using individual C-peptide clearance kinetics derived after bolus injection of biosynthetic human C-peptide. After 6-10 weeks on glyburide, the identical studies were repeated. In response to glyburide, the fasting plasma glucose level decreased from 12.3 +/- 1.2 to 6.8 +/- 0.9 mmol/L. Although the mean glucose over the 24 h of the meal study decreased from 12.7 +/- 1.4 to 10.8 +/- 1.2 mmol/L, postprandial hyperglycemia persisted on therapy, and after breakfast, glucose levels exceeded 10 mmol/L and did not return to fasting levels for the remainder of the day. Fasting serum insulin, plasma C-peptide, and the insulin secretion rate were not different before (152 +/- 48 pmol/L, 0.82 +/- 0.16 pmol/mL, and 196 +/- 34 pmol/min, respectively) and after (186 +/- 28 pmol/L, 0.91 +/- 0.11 pmol/mL, and 216 +/- 23 pmol/min, respectively) glyburide treatment despite lowering of the glucose level. However, average insulin and C-peptide concentrations over the 24-h period increased from 366 +/- 97 pmol/L and 1.35 +/- 0.19 pmol/mL to 434 +/- 76 pmol/L and 1.65 +/- 0.15 pmol/mL, respectively. The total amount of insulin secreted over the 24-h period rose from 447 +/- 58 nmol before therapy to 561 +/- 55 nmol while receiving glyburide. Insulin secretion was demonstrated to be pulsatile in all subjects, with periodicity ranging from 2-2.5 h. The number of insulin secretory pulses was not altered by glyburide, whereas pulse amplitude was enhanced after lunch and dinner, suggesting that the increased insulin secretion is characterized by increased amplitude of the individual pulses. In response to a hyperglycemic clamp at 300 mg/dL (16.7 mmol/L), insulin secretion rose more than 2-fold, from 47 +/- 9 nmol over the 3-h period before treatment to 103 +/- 21 nmol after glyburide therapy. We conclude that the predominant mechanism of action of glyburide in patients receiving therapy for 6-10 weeks is to increase the responsiveness of the beta-cell to glucose.(ABSTRACT TRUNCATED AT 400 WORDS)

Abnormal patterns of insulin secretion in non-insulin-dependent diabetes mellitus.

To determine whether non-insulin-dependent diabetes is associated with specific alterations in the pattern of insulin secretion, we studied 16 patients with untreated diabetes and 14 matched controls. The rates of insulin secretion were calculated from measurements of peripheral C-peptide in blood samples taken at 15- to 20-minute intervals during a 24-hour period in which the subjects ate three mixed meals. Incremental responses of insulin secretion to meals were significantly lower in the diabetic patients (P less than 0.005), and the increases and decreases in insulin secretion after meals were more sluggish. These disruptions in secretory response were more marked after dinner than after breakfast, and a clear secretory response to dinner often could not be identified. Both the control and diabetic subjects secreted insulin in a series of discrete pulses. In the controls, a total of seven to eight pulses were identified in the period from 9 a.m. to 11 p.m., including the three post-meal periods (an average frequency of one pulse per 105 to 120 minutes), and two to four pulses were identified in the remaining 10 hours. The number of pulses in the patients and controls did not differ significantly. However, in the patients, the pulses after meals had a smaller amplitude (P less than 0.03) and were less frequently concomitant with a glucose pulse (54.7 +/- 4.9 vs. 82.2 +/- 5.0, P less than 0.001). Pulses also appeared less regularly in the patients. During glucose clamping to produce hyperglycemia (glucose level, 16.7 mmol per liter [300 mg per deciliter]), the diabetic subjects secreted, on the average, 70 percent less insulin than matched controls (P less than 0.001). These data suggest that profound alterations in the amount and temporal organization of stimulated insulin secretion may be important in the pathophysiology of beta-cell dysfunction in diabetes.

Quantitative study of insulin secretion and clearance in normal and obese subjects.

The secretion and hepatic extraction of insulin were compared in 14 normal volunteers and 15 obese subjects using a previously validated mathematical model of insulin secretion and rate constants for C-peptide derived from analysis of individual decay curves after intravenous bolus injections of biosynthetic human C-peptide. Insulin secretion rates were substantially higher than normal in the obese subjects after an overnight fast (86.7 +/- 7.1 vs. 50.9 +/- 4.8 pmol/m2 per min, P less than 0.001, mean +/- SEM), over a 24-h period on a mixed diet (279.6 +/- 24.2 vs. 145.8 +/- 8.8 nmol/m2 per 24 h, P less than 0.001), and during a hyperglycemic intravenous glucose infusion (102.2 +/- 10.8 vs. 57.2 +/- 2.8 nmol/m2 per 180 min, P less than 0.001). Linear regression analysis revealed a highly significant relationship between insulin secretion and body mass index. Basal hepatic insulin extraction was not significantly different in the normal and obese subjects (53.1 +/- 3.8 vs. 51.6 +/- 4.0%). In the normal subjects, fasting insulin did not correlate with basal hepatic insulin extraction, but a significant negative correlation between fasting insulin and hepatic insulin extraction was seen in obesity (r = -0.63, P less than 0.02). This finding reflected a higher extraction in the six obese subjects with fasting insulin levels within the range of the normal subjects than in the nine subjects with elevated fasting insulin concentrations (61 +/- 3 vs. 45 +/- 6%, P less than 0.05). During the hyperglycemic clamp, the insulin secretion rate increased to an average maximum of 6.2-fold over baseline in the normal subjects and 5.8-fold in the obese subjects. Over the same time, the peripheral insulin concentration increased 14.1-fold over baseline in the normals and 16.6-fold over baseline in the obese, indicating a reduction in the clearance of endogenously secreted insulin. Although the fall in insulin clearance tended to be greater in the obese subjects, the differences between the two groups were not statistically significant. Thus, under basal, fasting conditions and during ingestion of a mixed diet, the hyperinsulinemia of obesity results predominantly from increased insulin secretion. In patients with more marked basal hyperinsulinemia and during intense stimulation of insulin secretion, a reduction in insulin clearance may contribute to the greater increase in peripheral insulin concentrations that are characteristic of the obese state.+

Self blood glucose monitoring: an adjunct to dietary and insulin management of the patient with diabetes.

The primary goal of diabetes management is to maintain blood glucose as near to normal as possible. Composition, size, and spacing of meals and snacks all have a substantial impact on blood glucose fluctuations and can be altered to improve glycemic control. Recent research studies focusing on the blood glucose response of various carbohydrate containing foods have found that responses vary considerably. Because the glucose response is influenced by numerous factors, it is difficult to predict how specific individuals will respond to a particular food. A technique known as self-blood glucose monitoring can be used by patients with diabetes to quantitate their own postprandial glucose rise from various foods. The technique itself is portable and relatively simple and is an accurate means of obtaining blood glucose values without using a clinical laboratory. Self-blood testing provides the patient with immediate feedback on the impact of dietary manipulation. Blood glucose records can be used in conjunction with diet records to make adjustments in the type and amount of food or insulin dose that would elicit the best glycemic response. The dietitian thus plays an integral role in identifying patterns in the blood glucose profile and assisting the patient in making intelligent dietary choices to improve diabetes control.

Blood pressure of rats as affected by diet and concentration of NaCl in drinking water.

In the first experiment, weanling rats were fed a grain ration or one of three semipurified diets high in fat, sucrose, or cornstarch. Rats in each dietary group were divided into two subgroups, one of which drank distilled deionized water whereas the other group drank 2% NaCl solution. Blood pressure and sodium intake were individually measured for each rat at weekly intervals for a 10-week period. Rats receiving the salt solution had higher mean blood pressures (127-178 mmHg) than rats offered distilled water (108-127 mmHg). When drinking solutions were the same, more severe rises in blood pressure occurred in rats fed the semipurified diets than in those rats fed grain. In a second experiment, rats were fed one of the four diets used in the first experiment; however, they received a 1% NaCl drinking solution for 9 weeks followed by a 1.5% NaCl solution for an additional 9 weeks. At Week 18, pressures among these groups of rats ranged from 136-140 mmHg, regardless of diet.

Effect of dam's diet on PCB accumulation in nursing Osborne Mendel pups.

Upon parturition, dams were fed high fat or high carbohydrate diets to which 1, 10, and 30 ppm of Aroclor 1254 were added to study the effect of diet on fat and PCB accumulation in nursing pups. The percentage of body fat in the carcasses of 0, 8, and 16 day old pups ranged from 2.2 to 18.2% and from 1.2 to 12.0% for animals suckled by dams fed high fat and high carbohydrate rations, respectively. Accumulation of Aroclor 1254 expressed as ppm wet weight or as total PCB's per pup was similar for animals nursed by dams fed either the high fat or high carbohydrate ration, but pups from dams fed a high carbohydrate ration also had significantly less body fat. Therefore, transfer of PCBs via the milk appears to be more a function of the amounts of PCB's consumed by the dam than the diet's ability to increase the percentage of body fat in the pups.