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Biomedical subjects

J R Boyce

Publications and source records attributed to J R Boyce.

At least 19 recordsLinked to original sources

Poor man's LMA: achieving adequate ventilation with a poor mask seal.

PURPOSE: This report describes a technique of ventilation prior to laryngoscopy and intubation that proved to be simple, inexpensive and effective for a patient whose airway evaluation suggested difficult mask ventilation. The technique is called Poor Man's LMA. CLINICAL FEATURES: A 60-yr-old male, measuring 170 cm, weighing 117 kg, edentulous and with a full beard, was to undergo uvulopalatopharyngoplasty. After induction of general anesthesia with a hypnotic, analgesic and non-depolarizing muscle relaxant, it was soon determined that mask bag ventilation was difficult due to an inadequate seal between the mask and the patient's full beard. To improve ventilation, an endotracheal tube was placed into the oropharynx, the lips and nose compressed by a colleague in order to prevent gas egress, and effective manual ventilation established by connecting the circle system to the endotracheal tube. Subsequent direct laryngoscopy and intubation were accomplished without incident. CONCLUSION: The patient's clinical features made conventional mask bag ventilation difficult and inadequate. The Poor Man's LMA technique improved oxygenation and ventilation in preparation for intubation. Further investigations on the usefulness of this technique are warranted.

Humans↗

Vessel dilator cricothyrotomy for transtracheal jet ventilation.

Needle cricothyrotomy is a safe, relatively easy procedure and has been described to enable pulmonary ventilation for patients in both elective and emergency situations. Conventional IV cannulae are short, thin-walled, and easily kinked and, therefore, do not provide a secure system to jet oxygen into the trachea. The vessel dilators of most 7-9 French introducer kits are firm, pliable, resist kinking, and can be passed easily into the tracheal lumen. We describe our experience with the use of vessel dilator cricothyrotomy to oxygenate and ventilate the lungs of patients in emergency and elective situations.

Catheterization↗

Plasmid profile analysis of salmonellae in a large-animal hospital.

The plasmid profiles of salmonellae isolated from the patients and environment of the Purdue Large Animal Hospital were used as markers to identify strains and to assess the impact of improvements in hospital operation on nosocomial salmonellosis. Plasmid profile analysis proved to be more sensitive than either serotyping or antimicrobial susceptibility testing in identifying Salmonella isolates. During June and July 1983, 29 of 34 salmonellae isolated were one of three strains with distinct plasmid profiles: one S. typhimurium var. Copenhagen, and two S. muenchen. Each of these strains was isolated from at least one patient and two environmental sites, suggesting the possibility that infections were hospital-acquired. Patient and environmental sampling was repeated in June and July 1984, after improvements had been made in hospital traffic flow and sanitation. In contrast to 1983, only seven isolates, representing six strains not seen previously, were obtained in 1984. None of these strains was isolated from both patient and environmental sources. The results indicate that the high incidence of clinical salmonellosis in 1983 was largely due to nosocomial infections. The decrease in the incidence of salmonellosis and the absence of the 1983 strains from samples taken in 1984 were presumed to be due to improvements made in hospital operation. This study demonstrates the value of plasmid analysis in monitoring nosocomial salmonellosis in a veterinary hospital.

Animals↗

Plasmid profile analysis of bovine isolates of Pasteurella haemolytica.

Pasteurella haemolytica isolates, obtained from cattle with respiratory tract disease, were characterized as to serotype, antimicrobial susceptibility, and plasmid content. Strains isolated from 2 groups of cattle were compared. Remarkable similarity was seen in the plasmid profiles of isolates of the same serotype. In contrast, isolates of 2 different serotypes had totally different plasmid profiles.

Animals↗

Selection of nonmucoid derivatives of mucoid Pseudomonas aeruginosa is strongly influenced by the level of iron in the culture medium.

We investigated the effects of cations on the stability in culture of mucoid strains pf Pseudomonas aeruginosa isolated from patients with cystic fibrosis by studying their effects on the selection of nonmucoid derivatives which arise by spontaneous mutation in cultures of mucoid organisms. Calcium ion concentrations in the range 0.55 to 1.85 mM had no effect on the growth or stability of the mucoid cultures. Higher levels (5.0 mM) inhibited the growth of both mucoid and nonmucoid cells. Likewise, magnesium ion in concentrations of 0.3 to 3.0 mM had no effect. The concentration of iron (either Fe2+ or Fe3+) had a profound effect on the selection of nonmucoid mutants in unshaken cultures of mucoid organisms. In medium containing 0.01 mM iron, nonmucoid mutants rapidly accumulated to a greater than 100-fold-higher frequency than the mucoid forms. Rates of accumulation of nonmucoid derivatives were lower in media containing lower concentrations of iron. The possible role of iron in the selection of nonmucoid cells from a population of mucoid P. aeruginosa is discussed.

Calcium↗