PubMed Health⌕ Search

Biomedical subjects

Richard Hall

Publications and source records attributed to Richard Hall.

8 recordsLinked to original sources
PubMed2006

Tight binding inhibitors of N-acyl amino sugar and N-acyl amino acid deacetylases.

Very potent inhibitors were synthesized for the enzymatic deacetylation of N-acetyl-d-glucosamine-6-phosphate (NagA) and N-acetyl-d-glutamate (DGD). The methyl phosphonamidate derivative of d-glucosamine-6-phosphate bound to N-acetyl-d-glucosamine-6-phosphate deacetylase with an equilibrium dissociation constant of 34 +/- 5 nM at pH 7.5 and an association rate constant of 6.1 x 103 M-1 s-1. The inhibition constant is 4000-fold lower than the Michaelis constant for the substrate N-acetyl-d-glucosamine-6-phosphate. N-Acetyl-d-glutamate deacetylase was inhibited by the methyl phosphonamidate derivative of d-glutamate with an inhibition constant of 460 +/- 70 pM at pH 7.6. The inhibitor bound to the enzyme 500 000-fold tighter than the Michaelis constant for N-formyl-d-glutamate. These compounds mimic the putative tetrahedral intermediate formed upon nucleophilic attack of an activated water molecule on the amide bond of the target substrate. These inhibitors should prove useful in the elucidation of the enzyme-substrate interactions for enzymes within the amidohydrolase superfamily.

Alcaligenes faecalis↗
PubMed2005

The use of tegaserod in critically ill patients with impaired gastric motility.

Studies have shown that early enteral nutrition in critically ill patients reduces the incidence of morbidity and death. Nonetheless, intolerance to gastric enteral nutrition is common in these patients as a result of gastroparesis. The use of prokinetic agents such as metoclopramide, domperidone, cisapride, and erythromycin can improve gastric emptying, but these agents are not without deleterious adverse effects. Tegaserod, a selective serotonin type 4 receptor partial agonist, was recently approved for treatment of women with irritable bowel syndrome. On the basis of tegaserod's mechanism of action, it was hypothesized that tegaserod may accelerate the return of gastric function in intensive care unit patients with gastroparesis. It would thus provide an additional agent for the management of gastroparesis with a more favorable safety profile. We present 3 case reports of the successful use of tegaserod in intensive care unit patients with impaired gastric motility. To our knowledge, the use of tegaserod in this setting has not been reported or studied previously.

Aged↗
PubMed2004

Evidence-based clinical practice guideline for the prevention of ventilator-associated pneumonia.

BACKGROUND: Ventilator-associated pneumonia (VAP) is an important patient safety issue in critically ill patients. PURPOSE: To develop an evidence-based guideline for the prevention of VAP. DATA SOURCES: MEDLINE, EMBASE, and the Cochrane Database of Systematic Reviews. STUDY SELECTION: The authors systematically searched for relevant randomized, controlled trials and systematic reviews that involved mechanically ventilated adults and were published before 1 April 2003. DATA EXTRACTION: Physical, positional, and pharmacologic interventions that may influence the development of VAP were considered. Independently and in duplicate, the authors scored the validity of trials; the effect size and confidence intervals; the homogeneity of results; and safety, feasibility, and economic issues. DATA SYNTHESIS: Recommended: The orotracheal route of intubation, changes of ventilator circuits only for each new patient and if the circuits are soiled, use of closed endotracheal suction systems that are changed for each new patient and as clinically indicated, heat and moisture exchangers in the absence of contraindications, weekly changes of heat and moisture exchangers, and semi-recumbent positioning in the absence of contraindications. Consider subglottic secretion drainage and kinetic beds. Not recommended: Sucralfate to prevent VAP in patients at high risk for gastrointestinal bleeding and topical antibiotics to prevent VAP. Because of insufficient or conflicting evidence, no recommendations were made about systematically searching for maxillary sinusitis, chest physiotherapy, the timing of tracheostomy, prone positioning, prophylactic intravenous antibiotics, or intravenous plus topical antibiotics. LIMITATIONS: No formal economic analysis was performed, and patient perspectives were not considered. CONCLUSION: If effectively implemented, this guideline may decrease the morbidity, mortality, and costs of VAP in mechanically ventilated patients.

Antibiotic Prophylaxis↗
PubMed2002

Oral versus vaginal misoprostol for labor induction.

OBJECTIVE: To compare the safety and effectiveness of vaginal with oral misoprostol for induction of labor. METHODS: A total of 107 women with clinical indication for induction were randomly assigned to receive oral or vaginal misoprostol. Doses of 100 microg of oral or 25 microg of vaginal misoprostol were given every 3-4 hours. If cervical ripening or active labor did not occur, repeated doses of oral (100-200 microg) or vaginal (25-50 microg) were given until labor was established. RESULTS: Fifty-nine women received oral misoprostol, and 48 received vaginal administration. Delivery time was similar for the vaginal and oral arms (1074 +/- 488 minutes versus 930 +/- 454 minutes, P =.11). Parity was significantly different (P =.04) for the vaginal and oral groups. The cesarean delivery rate was similar for the vaginal and oral arms (17% versus 15%, P =.72). The number of medication administrations was consistent between groups. Birth weight was not different for patients in the control and treatment groups (vaginal 3281 +/- 507 g versus oral 3359 +/- 541 g, P =.44). Chorioamnionitis and tachysystole were comparable for the oral and vaginal groups. There was no statistical difference in neonatal outcomes. Similar proportions of infants were admitted to the well baby nursery and intermediate care nursery. CONCLUSION: These findings indicate that, in a closely supervised hospital setting with adequate monitoring, oral misoprostol has the potential to induce labor as safely and effectively as its vaginal analogue.

Administration, Intravaginal↗
PubMed2002

Economic evaluation of propofol for sedation of patients admitted to intensive care units.

BACKGROUND: The goal of the current study was to evaluate the economic impact of propofol as compared with midazolam for sedating patients in the intensive care unit (ICU). METHODS: A randomized, unblinded, multicenter pharmacoeconomic trial captured health resource utilization and outcome measurements associated with sedation and treatment of patients in four ICUs across Canada. Statistical analysis was performed to investigate the difference in sedation quality, ICU length of stay, and other health resources used. The authors compared the costs (1997 Canadian dollars) associated with the two treatments. Two types of sensitivity analyses were performed. RESULTS: Although overall sedation duration was similar, propofol patients spent more time at adequately sedated status (60.2% vs. 44%; P = 0.01) and were extubated faster (median extubation time, 2.5 vs. 7.1 h; P = 0.001). The ICU length of stay and health resource utilization did not differ. The total cost per patient, including drug cost and ICU stay cost, did not differ between groups (median, $5,718 for propofol vs. $5,950 for midazolam; P = 0.94). The first sensitivity analysis suggested that the incremental cost (per patient) of propofol varies from an extra cost of $114 to a savings of $2,709. Based on a hypothetical model, the second sensitivity analysis showed a potential saving of $479 per patient as a result of improved discharge planning. CONCLUSION: The analysis demonstrated that using propofol resulted in a reduction of time to extubation and higher sedative regimen costs. There was no difference in intensity of resource use or ICU length of stay and hence in costs. Issues regarding discharge delay among propofol-treated patients remain to be explored.

Drug Costs↗
PubMedDate not supplied

Comparing computer-interpretable guideline models: a case-study approach.

OBJECTIVES: Many groups are developing computer-interpretable clinical guidelines (CIGs) for use during clinical encounters. CIGs use "Task-Network Models" for representation but differ in their approaches to addressing particular modeling challenges. We have studied similarities and differences between CIGs in order to identify issues that must be resolved before a consensus on a set of common components can be developed. DESIGN: We compared six models: Asbru, EON, GLIF, GUIDE, PRODIGY, and PROforma. Collaborators from groups that created these models represented, in their own formalisms, portions of two guidelines: American College of Chest Physicians cough guidelines [correction] and the Sixth Report of the Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure. MEASUREMENTS: We compared the models according to eight components that capture the structure of CIGs. The components enable modelers to encode guidelines as plans that organize decision and action tasks in networks. They also enable the encoded guidelines to be linked with patient data-a key requirement for enabling patient-specific decision support. RESULTS: We found consensus on many components, including plan organization, expression language, conceptual medical record model, medical concept model, and data abstractions. Differences were most apparent in underlying decision models, goal representation, use of scenarios, and structured medical actions. CONCLUSION: We identified guideline components that the CIG community could adopt as standards. Some of the participants are pursuing standardization of these components under the auspices of HL7.

Decision Support Systems, Clinical↗