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Peter Christenson

Publications and source records attributed to Peter Christenson.

5 recordsLinked to original sources
PubMed2006

Emergency Department Allies: a Web-based multihospital pediatric asthma tracking system.

OBJECTIVE: To describe the development of a Web-based multihospital pediatric asthma tracking system and present results from the initial 18-month implementation of patient tracking experience. DESIGN: The Emergency Department (ED) Allies tracking system is a secure, password-protected data repository. Use-case methodology served as the foundation for technical development, testing, and implementation. Seventy-seven data elements addressing sociodemographics, wheezing history, quality of life, triggers, and ED managment were included for each subject visit. SETTING: The ED Allies partners comprised 1 academic pediatric ED and 5 community EDs. POPULATION: Subjects with a physician diagnosis of asthma who presented to the ED for acute respiratory complaints composed the asthma group; subjects lacking a physician diagnosis of asthma but presenting with wheezing composed the wheezing group. RESULTS: The tracking-system development and implementation process included identification of data elements, system database and use case development, and delineation of screen features, system users, reporting functions, and help screens. For the asthma group, 2005 subjects with physician-diagnosed asthma were enrolled between July 15, 2002 and January 14, 2004. These subjects accounted for 2978 visits; 10.4% had > or = 3 visits. Persistent asthma was noted in 68% of the subjects. During the same time period, 1297 wheezing subjects with a total of 1628 ED visits (wheezing group) were entered into the tracking system. After enrollment, 57% of the subjects with > or = 1 subsequent ED visits received a physician diagnosis of asthma. CONCLUSIONS: Our sophisticated tracking system facilitated data collection and identified key intervention opportunities for a diverse ED wheezing population. A significant asthma burden was identified with significant rates of hospitalization, acute care visits and persistent asthma in 68% of subjects. The surveillance component provided important insights into health care issues of both asthmatic subjects and wheezing subjects, many of whom subsequently were diagnosed with asthma.

Asthma↗
PubMed2005

Serum fetuin-A in nondialyzed patients with diabetic nephropathy: relationship with coronary artery calcification.

BACKGROUND: Fetuin-A is the most potent circulating inhibitor of calcium phosphorus precipitation and, possibly, an important mediator of insulin resistance. METHODS: In order to determine the role of fetuin-A in the high coronary artery calcification (CAC) burden seen in nondialyzed individuals with diabetic nephropathy (DN), post-hoc analyses of data collected from a cross-sectional study of 88 patients with type 2 diabetes mellitus was done [age, 40-65 years; normoalbuminuria, N= 30 (Latinos); DN, N= 58 (Latinos and African Americans)]. RESULTS: The serum levels of fetuin-A were significantly higher among Latinos with DN when compared to either African Americans with DN or Latino diabetics with normoalbuminuria. Upon adjusting the data for race/ethnicity, there was a strong, direct relationship between serum fetuin-A levels and the CAC score (r= 0.22, P= 0.038) in the study cohort; however, a strong interaction between the nephropathy status and relationship of serum fetuin-A levels with CAC score was present (DN: r= 0.36, P= 0.006; diabetic controls, r= 0.0, P= 0.98). Among individuals with DN, the significance of the association persisted even after controlling the data for other predictors of CAC (partial r= 0.33, P= 0.018). Furthermore, there was a significant direct relationship between serum fetuin-A and serum triglycerides (partial r= 0.27, P= 0.01) and albumin (partial r= 0.30, P= 0.005), and an inverse relationship with glomerular filtration rate (r=-0.24, P= 0.03). CONCLUSION: This first study in early stages of diabetic chronic kidney disease shows that the role of serum fetuin-A may be far more complex than previously described. During predialysis stage of DN, there is a direct relationship between serum fetuin-A levels and CAC score. The reasons for this association in the presence of nephropathy are unclear, but may be secondary to proatherogenic insulin resistance.

Adult↗
PubMed2004

Non-linear cardiac output dynamics during ramp-incremental cycle ergometry.

Published literature asserts that cardiac output (Q(.) = V(.) >O(2)x1/C((a-v))O(2)) increases as a linear function of oxygen uptake with a slope of approximately 5-6 during constant work rate exercise. However, we have previously demonstrated that C((a-v))O(2) has a linear relationship as a function of V(.)O(2) during progressively increasing work rate incremental exercise. Therefore, we hypothesized that Q(.) may indeed have a non-linear relationship with respect to V(.)O(2) during incremental, non-steady state exercise. To investigate this hypothesis, we performed five maximal progressive work rate exercise studies in healthy human subjects. Q(.) was determined every minute during exercise using measured breath-by-breath V(.) >O(2), and arterial and pulmonary artery measurements of PO(2), hemoglobin saturation, and content. Q(.) was plotted as a function of V(.) >O(2) and the linear and non-linear (first order exponential and hyperbolic) fits determined for each subject. Tests for linearity were performed by assessing the significance of the quadratic terms added to the linear relation using least squares estimation in linear regression. Linearity was inadequate in all cases (group P<0.0001). We conclude that cardiac output is a non-linear function of V(.)O(2 )during ramp-incremental exercise; the pattern of non-linearity suggests that while the kinetics of Q(.) > are faster than those of V(.) >O(2) they progressively slow as work rate (and V(.) >O(2)) increases.

Adult↗
PubMed2004

Determinants of coronary artery calcification in diabetics with and without nephropathy.

BACKGROUND: In the general population, including those with diabetes mellitus, coronary artery calcification (CAC) correlates with atherosclerotic plaque burden. On the other hand, accumulating evidence suggests that disordered mineral metabolism significantly contributes to the vascular calcification in individuals with end-stage renal disease (ESRD). METHODS: In order to determine the relative contribution of accelerated atherosclerosis and disordered mineral metabolism to CAC in chronic kidney disease, a pilot study of 90 patients with type 2 diabetes mellitus was done [age, 40-65 years; normoalbuminuria, N= 30; diabetic nephropathy (DN), N= 60]. RESULTS: CAC was more prevalent and severe among individuals with DN compared to diabetic controls (odds ratio for prevalence 8.1, 95% CI 2.3-28.5; median scores, 66 vs. 4, P < 0.001). None of the 4 measures of disordered mineral metabolism evaluated in this study (serum calcium, phosphorus, parathyroid hormone, and 1,25 di-hydroxy vitamin D levels) correlated with the prevalence or severity of CAC, or accounted for the differences seen between DN and diabetic controls. On the other hand, the difference in the severity of hypertension (number of antihypertensive medications) appeared to account for the differences in CAC burden seen between DN and diabetic controls. CONCLUSION: This first such study of nondialyzed individuals with DN suggests that, unlike ESRD patients, the high CAC burden seen at earlier stages of diabetic chronic kidney disease is probably unrelated to disordered mineral metabolism. The relationship between the severity of hypertension and CAC burden provides a probable target for intervention in the predialysis phase of DN.

Adult↗