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Biomedical subjects

R Davis

Publications and source records attributed to R Davis.

At least 199 records · Page 11Linked to original sources

The role of previous birthweight on risk for macrosomia in a subsequent birth.

Macrosomia (birthweight > or = 4,500 gm) is associated with increased perinatal morbidity and mortality. Although past studies have evaluated risk factors for macrosomia, little is known about the effect of a prior macrosomic birth on the risk for a macrosomic infant in a subsequent birth. To assess the risk for delivery of a macrosomic infant subsequent to a previous macrosomic infant, we performed a population-based cohort study utilizing the Washington State linked infant birth file for 1984-1990. We identified 1,793 infants with birthweight > or = 4,500 gm who were linked to a subsequent birth and 3,596 randomly selected infants with birthweight of < 4,500 gm also linked to a subsequent livebirth. We then compared the risks for subsequent macrosomic births between the two groups. Infants with birthweights > or = 4,500 gm were 7.0 times more likely (95% confidence interval = 5.4-9.1) to have a subsequent macrosomic sibling than were infants with smaller birthweights, after controlling for pregnancy smoking status, parity, and gestational age. Race, maternal age or marital status, and diabetes mellitus did not materially affect this relation. The overall prevalence of macrosomic infants subsequent to a previous macrosomic birth was 22%, a proportion that did not vary notably with parity, or when paternity changed between successive births. Mothers with one macrosomic infant are at markedly increased risk for repeat macrosomic births.

Adult↗

Fatal outcome of jugular vein cannulation.

We describe the case of a woman who had cannulation of the internal jugular vein for the placement of a hemodialysis catheter. The procedure was unsuccessful and resulted in a retropharyngeal hematoma, which in turn caused severe compression on a carotid artery that was already severely narrowed by atherosclerosis. This resulted in massive cerebral hemispheric infarction and death. During the course of hospitalization, ultrasonography, computed tomography, and angiographic studies were done. Cannulation of neck vessels in patients with bleeding diatheses must be done with caution, especially in the presence of severe stenotic disease of the carotid arteries.

Aged↗

Isla Vista virus: a genetically novel hantavirus of the California vole Microtus californicus.

Prospect Hill virus (PH) was isolated from a meadow vole (Microtus pennsylvanicus) in 1982, and much of its genome has been sequenced. Hantaviruses of other New World microtine rodents have not been genetically characterized. We show that another Microtus species (the California vole M. californicus) from the United States is host to a genetically distinct PH-like hantavirus, Isla Vista virus (ILV). The nucleocapsid protein of ILV differs from that of PH by 11.1% and a portion of the G2 glycoprotein differs from that of PH by 19.6%. ILV antibodies were identified in five of 33 specimens of M. californicus collected in 1975 and 1994-1995. Enzymatic amplification studies showed that 1975 and 1994-1995 ILV genomes were highly similar. Secondary infection of Peromyscus californicus was identified in Santa Barbara County, California. A long-standing enzootic of a genetically distinct hantavirus lineage is present in California voles.

Animals↗

A real job for managers in the health service.

Suggests that current conditions in and around the NHS are creating stressed and difficult work for NHS managers--this obscures the fact that, in common with all managers in the West, they have been given the wrong work to do. Proposes that Western management is built on command and control assumptions which are entirely dysfunctional for today's work. Outlines a challenge to the principle of command and control and describes, with the help of W. Edwards Deming's views, what an alternative picture of work could achieve.

Administrative Personnel↗

The role of autologous blood transfusion in joint replacement surgery.

The efficacy of predeposited autologous blood transfusion (PABT) with and without intra/postoperative blood salvage to reduce or eliminate the need for homologous blood transfusion (HBT) in primary total hip or knee replacement surgery was investigated by retrospective and prospective studies. Depending on the type of surgery, one to three units of PABT eliminated the need for HBT in 50 to 78% of patients, but, intra/postoperative blood salvage alone reduced the need only in 11 to 29%. In contrast, blood salvage, when combined with three units of PABT, eliminated the need for HBT in all patients undergoing primary joint replacement surgery. A cost comparison analysis showed that blood salvage was more expensive than PABT, and therefore it should be limited to patients who had predeposited fewer than three units of autologous blood.

Adult↗

Diclofenac/misoprostol. A review of its pharmacology and therapeutic efficacy in painful inflammatory conditions.

Diclofenac is a well established nonsteroidal anti-inflammatory drug (NSAID) used in the treatment of a variety of painful inflammatory conditions. Although generally well tolerated, diclofenac, like other NSAIDs, is associated with gastrointestinal adverse effects which infrequently can be serious and/or life-threatening. Misoprostol, a prostaglandin E1 analogue, reduces the incidence of NSAID related ulcers, both gastric and duodenal. The lack of conclusive pharmacoeconomic data for misoprostol and the widespread use of NSAIDs makes routine administration of misoprostol difficult to justify for all NSAID users. However, it appears to be an economically warranted approach in the elderly, who are at particularly high risk for NSAID-related gastrointestinal complications. The fixed combination of diclofenac 50mg and misoprostol 200 micrograms administered 2 to 3 times daily for 4 to 12 weeks has shown equivalent therapeutic efficacy to diclofenac (alone or combined with placebo), piroxicam and naproxen, and was slightly more effective than ibuprofen in clinical studies in patients with a variety of painful inflammatory conditions. No significant differences in therapeutic efficacy were noted between elderly (aged > or = 65 years) and younger patients in these studies. Gastrointestinal adverse events are common with diclofenac and misoprostol, administered alone or in combination. Diarrhoea (presumably attributable to the misoprostol component) appears to be more frequent in diclofenac/misoprostol recipients than in those receiving diclofenac alone or combined with placebo. However, diclofenac/misoprostol recipients had significantly fewer gastroduodenal ulcers at the end of treatment relative to patients receiving comparators in clinical trials. In addition, the types and incidences of adverse events are similar in elderly and younger patients. Routine ulcer prophylaxis with misoprostol in all NSAID users is not warranted from a pharmacoeconomic viewpoint. In common with other fixed combination products, dosage flexibility is somewhat compromised with diclofenac/misoprostol. However, once drug dosages are determined in the individual patient, the fixed combination of diclofenac and misoprostol offers the potential for increased patient convenience and possibly patient compliance, and lower drug acquisition costs than those of the individual drugs used together. Thus, it should be considered a useful treatment option in appropriately selected patients with a high risk for serious NSAID-related gastrointestinal complications who require NSAID therapy.

Aged↗

Aprotinin. A review of its pharmacology and therapeutic efficacy in reducing blood loss associated with cardiac surgery.

Patients undergoing cardiac surgery with cardiopulmonary bypass (CPB) experience transient haemostatic defects as a result of adverse changes to their blood components, blood cells and specific coagulation proteins. Aprotinin is a naturally occurring serine protease inhibitor isolated from bovine lung tissue which inhibits kallikrein and plasmin. A high dose aprotinin regimen (aprotinin 280mg loading dose over 20 to 30 minutes after anaesthesia induction followed by 70 mg/h for the duration of the operation and 280mg added to the priming fluid of the CPB circuit) has been used during CPB in order to reduce perioperative bleeding. Recent clinical trials confirm the efficacy of high dose aprotinin in reducing blood loss and transfusion requirements associated with primary cardiac procedures such as coronary artery bypass graft (CABG) or heart valve replacement surgery. High dose aprotinin is also effective in procedures known to possess a high risk for excessive blood loss, such as repeat CABG or heart valve replacement surgery, cardiac surgery in patients with infective endocarditis, or in patients receiving aspirin (acetylsalicylic acid) before surgery. Studies indicate that low dose aprotinin (280mg added to CPB pump prime fluid) is effective in reducing blood loss and transfusion requirements in patients undergoing primary CABG surgery. Additionally, low dose aprotinin regimens (both 280mg added to CPB pump prime fluid and 50% of the high dose regimen) have shown some benefit in repeat CABG surgery; however, more studies are needed to confirm these results. Data from clinical trials indicate that aprotinin is well tolerated. The types and incidences of adverse events reported with aprotinin therapy are generally consistent with those associated with major cardiac surgery, and are not significantly different from those observed in control groups. A trend towards lower graft patency rates, detected by ultrafast computerised tomography (CT), has been observed in aprotinin recipients in 2 US trials. These differences did not reach statistical significance and should be interpreted with caution since the ability of ultrafast CT to determine graft patency has not been validated. Mildly elevated plasma creatinine levels are more commonly observed in aprotinin-treated patients; these changes are transient in the majority of patients. Both high dose and low dose aprotinin regimens (280mg added to CPB pump prime fluid or 50% of the high dose regimen) have reduced blood loss and transfusion requirements in patients undergoing primary and repeat cardiac surgery. The role of aprotinin in paediatric cardiac surgery needs further clarification, while well-designed studies comparing aprotinin with other agents which inhibit fibrinolysis are also awaited with interest.(ABSTRACT TRUNCATED AT 400 WORDS)

Aprotinin↗

Budesonide. An appraisal of the basis of its pharmacoeconomic and quality-of-life benefits in asthma.

Budesonide is an inhaled corticosteroid that is used prophylactically to reduce the underlying inflammation and consequent airways narrowing associated with asthma. Widespread clinical experience has shown that inhaled budesonide is effective and well tolerated, and its use is well established in the management of adult and childhood asthma. In developed countries, asthma is a major health problem and consumes a large proportion of healthcare resources. Both the prevalence and severity of asthma appear to be increasing. Additionally, asthma-related mortality has been reported to have gradually increased since the mid- to late-1970s in many countries, possibly due to undertreatment and/or suboptimal management of the disease. Current guidelines recommend a shift away from initial treatment with oral bronchodilators, such as theophylline, or regular use of beta 2-agonist inhalers, toward the earlier use of more expensive inhalers containing corticosteroids. Inhaled bronchodilators are still used as indicated for treatment of acute attacks. Data suggest that the acquisition cost of budesonide is more than offset by decreased morbidity and reductions in costs associated with acute asthma exacerbations. Both once-daily administration and its administration in dry powder form via Turbuhaler appear to be well accepted by patients; these factors may potentially improve patient compliance with therapy. Budesonide appears to have positive effects on some quality-of-life indices, although studies using validated quality-of-life instruments are needed to confirm these conclusions. Modelling studies would be helpful in order to assess the possible economic benefits to society through reduction of the considerable direct and indirect costs of asthma and cost-effectiveness comparisons with other inhaled corticosteroids are needed to clarify its relative positioning in this regard. Until then, the available data provide an encouraging pharmacoeconomic rationale for budesonide as first-line asthma therapy, and a good basis for future pharmacoeconomic analysis of asthma management.

Asthma↗

Terbinafine. A pharmacoeconomic evaluation of its use in superficial fungal infections.

Terbinafine is an orally and topically active allylamine antifungal drug which is an effective and well tolerated therapy for a wide range of superficial dermatophyte infections. In contrast to most other commonly prescribed antifungal agents, terbinafine is fungicidal in vitro and possesses improved pharmacokinetic properties with respect to drug penetration into nail tissue following oral administration. These properties enable terbinafine to achieve high success rates with shortened therapy regimens in the treatment of dermatophyte skin infections and onychomycosis. Pharmacoeconomic analyses have shown that oral terbinafine, with its higher rates of clinical efficacy and lower rates of relapse/reinfection, is less costly and more cost effective than oral griseofulvin, ketoconazole and itraconazole when used as initial therapy in the treatment of onychomycosis. However, some points regarding the clinical efficacy of itraconazole relative to terbinafine and the drug treatment regimens used in these studies need further clarification. In the management of tinea pedis, a cost analysis suggested that initial therapy with terbinafine 1% cream was more costly than initial therapy with miconazole, oxiconazole or clotrimazole. However, in cost-effectiveness studies, terbinafine had a lower cost per disease-free day than ciclopirox, clotrimazole, ketoconazole and miconazole in the treatment of dermatophyte skin infections. In conclusion, available clinical and pharmacoeconomic data support the use of topical terbinafine as first-line treatment of dermatophyte skin infections unless the acquisition cost of terbinafine is markedly greater than that of alternative topical antifungal agents. Oral terbinafine can be recommended as a cost-effective first-line treatment, preferable to oral griseofulvin, ketoconazole and itraconazole, in patients with dermatophyte onychomycosis.

Antifungal Agents↗

Oral sumatriptan is effective and well tolerated for the acute treatment of migraine: results of a multicenter study.

The efficacy and tolerability of oral sumatriptan (Imitrex tablets) were assessed in 187 migraineurs enrolled in a randomized, double-blind, parallel-group, placebo-controlled study. In the clinic, patients received oral sumatriptan 25 mg, 50 mg, or 100 mg, or placebo, for the treatment of a migraine attack. The results demonstrate that by 2 hours postdose, 52 to 57% of patients treated with sumatriptan 25 mg, 50 mg, 100 mg compared with 17% of patients treated with placebo achieved relief of headache (p < 0.05 for each sumatriptan group vs placebo). By 4 hours postdose, 65 to 78% of sumatriptan-treated patients compared with 19% of placebo-treated patients achieved relief of headache (p < 0.05 for each sumatriptan group vs placebo). Oral sumatriptan also effectively relieved nausea and photophobia and improved clinical disability. No serious or unusual adverse events were reported, and the pattern and incidence of adverse events did not vary among the sumatriptan doses. Each dose--25 mg, 50 mg, or 100 mg--of sumatriptan was effective and generally well tolerated.

Administration, Oral↗

Oral sumatriptan for the acute treatment of migraine: evaluation of three dosage strengths.

This randomized, double-blind, parallel-group, placebo-controlled study evaluated the efficacy and tolerability of oral sumatriptan (Imitrex tablets) in 259 migraineurs. In the clinic, patients received oral sumatriptan 25 mg, 50 mg, or 100 mg, or placebo for the treatment of a migraine attack. The results indicate that by 2 hours post-dose, 50 to 56% of patients treated with any of the three doses, compared with 26% of patients treated with placebo, achieved relief of headache (p < 0.05 for each sumatriptan group vs placebo). By 4 hours postdose, 68 to 71% of sumatriptan-treated patients, compared with 38% of placebo-treated patients, achieved relief of headache (p < 0.05 for each sumatriptan group vs placebo). Oral sumatriptan was similarly effective at relieving nausea and photophobia and at reducing clinical disability. The pattern and incidence of adverse events did not differ between treatment groups. All doses--25 mg, 50 mg, and 100 mg--of sumatriptan were effective and generally well tolerated. Dosing should be individualized according to the needs of the patient.

Administration, Oral↗

Paradoxical embolism.

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Cerebrovascular Disorders↗