Biomedical subjects

R A Quercia

Publications and source records attributed to R A Quercia.

23 records · Page 2Linked to original sources

PubMed1986

Bacteriologic contamination of intravenous infusion delivery systems in an intensive care unit.

Seventy intensive care unit patients were admitted to a double-blind prospective study to determine the level of contamination associated with the admixture and administration of intravenous solutions and whether intravenous filtersets prevented bacteremia. Patients were randomly assigned a 0.22 micron filterset (real filter) or a filter cartridge without a 0.22 micron membrane (blank filter) on all possible intravenous lines. Forty-six (14.1 percent) real filtersets and 38 (11.3 percent) blank filtersets were found to be contaminated, and overall 30 patients (42.4 percent) were found to have extrinsically contaminated intravenous administration systems at least once during the study. Bacterial adherence to the plastic cartridge was demonstrated to be responsible for culture-positive blank filtersets. Staphylococcus epidermidis was the organism most frequently isolated from real and blank filtersets. Epidemiologic surveillance identified 10 patients with blank filtersets and three patients with real filtersets with clinically significant hospital-acquired bacteremias during the study period. It is concluded that a significant level of extrinsic contamination of intravenous infusion delivery systems occurred on the intensive care unit; documented clinically significant nosocomial bacteremias occurred less often in those patients who had a 0.22 micron bacterial retention filter on all possible intravenous lines.

Bacteriological Techniques↗

PubMed1984

Treatment and prevention of oropharyngeal candidiasis.

As more potent antibacterial drugs are used to combat infections and as more patients with impaired defenses against infection are treated, other organisms, like fungi, have become important pathogens. Fungi of all types may appear in this setting, but Candida species are the most common, usually beginning as an infection in the oropharynx. Although oropharyngeal candidiasis usually remains localized, it may spread elsewhere, leading to a fatal outcome. Controversy still exists regarding the best drug to prevent or treat oropharyngeal candidiasis, but clotrimazole given as a troche may be the best choice at the moment owing to its high clinical success rate, safety, cost effectiveness, and high patient acceptability. There remains a need for more randomized and controlled studies comparing the efficacy of nystatin, ketoconazole, and clotrimazole in high-risk patients in whom invasive candidiasis remains a frequent problem.

Adolescent↗

PubMedDate not supplied

Total nutrient admixture: a review.

The TNA system of nutritional support has become very popular and offers some unique advantages over the traditional method of administering TPN to hospitalized and home patients. However, these advantages as outlined in this review, must be carefully weighed against potential disadvantages before the TNA system is employed as a nutritional support modality. It should also be noted that the stability of TNA systems is not well established since many stability studies do not provide specific information regarding formulations tested. In addition, many studies do not utilize methods to determine the entire spectrum of particle size and distribution. Droplet size in TNA systems attain a diameter several times larger than the 0.2 to 0.4 micron of manufacturer's lipid emulsions and naturally occurring chylomicrons. Although the administration of the TNA system has not been associated with any acute toxicity, the long-term consequences of infusing droplets larger than 0.4 micron is not definitely known. In addition, the biological implications of using the TNA system need to be elucidated. Subtle differences in the properties of the lipid emulsion can affect the way it is metabolized by the body. Wretlind has mentioned that two apparently similar soybean oil emulsions, Intralipid, and Lipofundin are handled differently by the body. Minor differences in the phospholipid layer of the droplets were postulated as a cause. Certainly the nature of the emulsifying layer of phospholipid on TNA system droplets is modified and therefore may be metabolized differently. The recent report of enhanced growth of microorganisms in TNA systems is also worrisome.(ABSTRACT TRUNCATED AT 250 WORDS)

Chemical Phenomena↗

PubMedDate not supplied

The growth of microorganisms in total parenteral nutrition admixtures.

Total nutrient admixtures (TNAs) containing glucose, amino acids, and lipid emulsion in one container and amino acid/dextrose solutions [conventional total parenteral nutrition (TPN) formulations] were studied in a controlled laboratory experiment for their ability to support the growth of microorganisms. Both TNA and conventional TPN formulations for peripheral and central venous administration with standard additives were inoculated with microorganisms to provide 10(1)-10(2) colony-forming units/ml (CFU/ml) of Staphylococcus epidermidis, Escherichia coli, Pseudomonas aeruginosa, Klebsiella pneumoniae, and Candida albicans. The admixtures were stored at room temperature and samples for quantitative microbiology were taken at time 0, 6, 12, 24, 48, 72, and 96 hr. K. pneumoniae, E. coli, and P. aeruginosa were able to proliferate in central TNAs, but the growth of these organisms was retarded in conventional TPN solutions. In the peripheral formulations, K. pneumoniae and E. coli proliferated in both the TNA and conventional TPN systems, whereas P. aeruginosa grew well only in the peripheral TNA. S. epidermidis was not able to grow in any admixtures tested; however, C. albicans grew well in all admixtures, but growth was slower in the conventional central TPN. In conclusion, peripheral and central TNAs supported the growth of microorganisms significantly better than conventional TPN solutions.

Amino Acids↗

PubMedDate not supplied

Selenium deficiency and fatal cardiomyopathy in a patient receiving long-term home parenteral nutrition.

Fatal cardiomyopathy in a patient who received home parenteral nutrition (HPN) for eight years is reported, and the relationship of selenium deficiency to cardiomyopathy and other adverse effects is discussed. A 42-year-old white man with Crohn's disease who was receiving HPN was admitted to the hospital with severe chest pain and dyspnea. During the three days following admission, his symptoms of congestive heart failure and compensated metabolic acidosis persisted despite treatment. On hospital day 6, the patient developed increased ventricular irritability and refractory ventricular fibrillation and died. At autopsy, the heart weighted 500 g, all chambers were dilated, and the myocardium was grossly flabby. Extremely low concentrations of selenium (5-12% of normal) were found in plasma, heart, liver, and kidney tissue samples. The pathological findings in this patient were similar to those in two previously reported cases and strongly suggest that the fatal cardiomyopathy was secondary to selenium deficiency. Selenium is an integral part of the enzyme glutathione peroxidase, which plays an important role in the metabolism of tissues and organs. For metabolically stable patients receiving total parenteral nutrition, the suggested selenious acid dosage is 25-60 micrograms/day for adults and 1.4-30 micrograms/kg/day for pediatric patients. In selenium-depleted adults, a dosage of 100 micrograms/day administered intravenously for 21-31 days has been recommended to reverse symptoms. All HPN patients and hospitalized patients receiving extended parenteral nutrition should be monitored for selenium deficiency and given supplements if necessary.

Adult↗