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David M Ward

Publications and source records attributed to David M Ward.

22 records · Page 2Linked to original sources
PubMed2002

A novel method for regional citrate anticoagulation in continuous venovenous hemofiltration (CVVHF).

BACKGROUND: Continuous renal replacement therapy (CRRT) is increasingly used in managing acute renal failure (ARF) as it offers hemodynamic stability and significant solute clearance in this setting. However, it also requires anticoagulation. Traditionally, heparin has been the anticoagulant of choice but this increases hemorrhagic risk in already high-risk ARF patients. Regional citrate anticoagulation offsets this risk. However, it can be difficult to manipulate regional anticoagulation in CRRT. Moreover, citrate CRRT has been plagued by short optimal filter patency times. METHODS: We designed a novel citrate-based anticoagulation schema for continuous venovenous hemofiltration (CVVHF). We implemented this schema prospectively in caring for 24 individuals admitted to the intensive care unit with ARF requiring CRRT. Each individual had a contraindication to systemic anticoagulation. We evaluated filter patency using Kaplan-Meier methodology, comparing the effect of this citrate-CVVHF system to historical, saline-flush control CVVHF systems. RESULTS: 58 filters ran for a total of 2637.5 h. Average filter patency time was 45.4 +/- 25.5 h. At 48 h, 70% of the CVVHF-citrate system filters remained patent compared to only 16% of historical control saline-flush systems (p = 0.0001). The average filtered urea nitrogen/blood urea nitrogen ratio was 0.84 +/- 0.06 with an average urea clearance of 28.5 +/- 4.1 mL/min for CVVHF-citrate-treated individuals. Only three patients experienced transient complications related to CVVHF-citrate with resolution of these complications within 24 h. Ultimately, 58.3% of the CVVHF-citrate-treated patients survived to ICU discharge. CONCLUSIONS: This novel CVVHF-citrate system achieved excellent clearance and dramatically improved filter patency compared to saline-flush systems. Moreover, it did so with minimal toxicity.

Acute Kidney Injury↗
PubMed2002

Microscopic examination of distribution and phenotypic properties of phylogenetically diverse Chloroflexaceae-related bacteria in hot spring microbial mats.

We investigated the diversity, distribution, and phenotypes of uncultivated Chloroflexaceae-related bacteria in photosynthetic microbial mats of an alkaline hot spring (Mushroom Spring, Yellowstone National Park). By applying a directed PCR approach, molecular cloning, and sequence analysis of 16S rRNA genes, an unexpectedly large phylogenetic diversity among these bacteria was detected. Oligonucleotide probes were designed to target 16S rRNAs from organisms affiliated with the genus Chloroflexus or with the type C cluster, a group of previously discovered Chloroflexaceae relatives of this mat community. The application of peroxidase-labeled probes in conjunction with tyramide signal amplification enabled the identification of these organisms within the microbial mats by fluorescence in situ hybridization (FISH) and the investigation of their morphology, abundance, and small-scale distribution. FISH was combined with oxygen microelectrode measurements, microscope spectrometry, and microautoradiography to examine their microenvironment, pigmentation, and carbon source usage. Abundant type C-related, filamentous bacteria were found to flourish within the cyanobacterium-dominated, highly oxygenated top layers and to predominate numerically in deeper orange-colored zones of the investigated microbial mats, correlating with the distribution of bacteriochlorophyll a. Chloroflexus sp. filaments were rare at 60 degrees C but were more abundant at 70 degrees C, where they were confined to the upper millimeter of the mat. Both type C organisms and Chloroflexus spp. were observed to assimilate radiolabeled acetate under in situ conditions.

Autoradiography↗
PubMedDate not supplied

The case for the use of evidence-based management research for the control of hospital costs.

This article explores the current state of the creation and use of evidence by managers for cost containment in hospitals. We assert that hospitals do not know enough about what things cost, and until they get evidence on costs, it is not likely that much can be done to narrow the chasm between common practice and best practice. Part of the problem is that managers do not seek out available evidence that exists, and part of the problem is a lack of sufficient research efforts to generate evidence for managers to use. The article strives to help direct future efforts by researchers and managers in the area of evidence-based cost containment research by presenting a framework for priorities that managers and researchers can use to increase the amount of research done to generate evidence and to increase the use of evidence by health care managers.

Cost Control↗