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Biomedical subjects

C G Mayhall

Publications and source records attributed to C G Mayhall.

At least 37 records · Page 2Linked to original sources
PubMed1990

Clinical predictors of infection of central venous catheters used for total parenteral nutrition.

To identify predictors of infection in catheters used for total parenteral nutrition (TPN), clinical and microbiological data were prospectively collected on 169 catheter systems (88 patients). Based on semiquantitative catheter cultures, infection was associated with a positive insertion site skin culture taken close to the time of catheter removal (relative risk [RR] = 4.50), especially one yielding greater than or equal to 50 colonies of an organism other than coagulase-negative staphylococci. Infection was also associated with erythema at the insertion site greater than 4 mm in diameter (RR = 2.93). In a subset of 67 catheters for which blood cultures were obtained, infection was also associated with a positive peripheral venous blood culture (RR = 5.90) and a positive central venous blood culture obtained through the catheter (RR = 5.44). Based on a logistic regression model, periodic cultures of the insertion site should be useful in evaluating subsequent fever in stable patients with indwelling central venous catheters. Another source of fever is likely if inflammation is absent and there is either no colonization or there is colonization by less than 50 colonies of coagulase-negative staphylococci at the insertion site. Conversely, the catheter should be removed and cultured semiquantitatively if the site is colonized by an organism other than coagulase-negative staphylococci. We suggest that blood culture results add little to the risk estimate in these situations.

Adult↗
PubMed1989

Risk factors for intraamniotic infection: a prospective epidemiologic study.

To determine the cumulative incidence of intraamniotic infection in our hospital and to identify potential risk factors for infection, 408 consecutive patients were followed up prospectively to determine development of intraamniotic infection. The clinical diagnosis of intraamniotic infection was made in 43 (10.5%) patients. Patients with intraamniotic infection were younger, of lower gravidity and parity, more likely to require oxytocin augmentation, and more likely to be monitored internally than were patients who were not infected. They also had longer durations of labor, ruptured membranes, and hospitalization before delivery, had significantly more vaginal examinations, and were more likely to be delivered of infants by cesarean section, as compared with patients without infection. Logistic regression analysis identified four variables independently associated with intraamniotic infection: the number of vaginal examinations, duration of ruptured membranes, use of internal monitors, and duration of total labor. Further study is necessary to clarify the role of these risk factors in the pathogenesis of intraamniotic infection so that infection control strategies can be developed.

Adult↗
PubMed1988

A prospective study of infections in hemodialysis patients: patient hygiene and other risk factors for infection.

We performed a prospective randomized study on 71 patients on chronic outpatient hemodialysis to determine whether a sterile technique was better than a clean technique for preparation of the skin over the vascular access site prior to cannulation. In addition, we wanted to determine overall and site-specific infection rates, microbial etiologies of infection, and risk factors for infection. The overall infection rate was 4.7 infections per 100 dialysis months; the vascular access-site infection rate was 1.3 infections per 100 dialysis months; and the rate for bacteremia was 0.7 cases per 100 dialysis months. Staphylococcus aureus was the most common pathogen, but infections were equally divided between gram-positive cocci and gram-negative bacilli. Advanced age (P = 0.02), a low Karnofsky activity score (P = 0.05), poor hygiene (P = 0.0004) and number of hospitalizations (P = 0.0002) were risk factors for infections in general while only poor hygiene (P = 0.002) was a risk factor for vascular access-site infection. Sterile preparation of the skin over the vascular access site was no more effective at preventing infection than was clean technique (P = 0.80). Maintenance of good personal hygiene may be one of the most important measures for prevention of infections in hemodialysis patients.

Adult↗
PubMed1988

Prospective study of microbial colonization of the nose and skin and infection of the vascular access site in hemodialysis patients.

We conducted a prospective study of nasal and skin floras in 71 patients receiving chronic hemodialysis. We wished to determine whether a sterile skin preparation technique was more effective than a clean technique in removing microorganisms from the skin of the vascular access site. We also examined the effect of administration of antibiotics and status of patient hygiene on microbial flora. The presence of Staphylococcus aureus in the nose had a low predictive value for the simultaneous presence of the microorganism on the skin. The status of skin colonization can be accurately assessed only by culture of the skin. Sterile technique was no more effective at removing microorganisms from skin than was clean technique. Antibiotics significantly affected nasal flora but not skin flora. S. aureus was significantly more likely to remain on the skin after application of an antiseptic in patients with poor hygiene than in patients with good hygiene (P = 0.002). Patients with poor hygiene also had a significantly higher concentration of S. aureus on the skin of the vascular access site after application of antiseptic than patients with good hygiene (P = 0.005). We found no evidence to support a change from clean to sterile technique for skin preparation, but improvement in personal hygiene may be an effective strategy for prevention of vascular access infections.

Adult↗
PubMed1987

Outbreak due to methicillin- and rifampin-resistant Staphylococcus aureus: epidemiology and eradication of the resistant strain from the hospital.

A methicillin- and rifampin-resistant strain of Staphylococcus aureus was introduced into a university hospital by interstate transfer of an infected surgical patient. An outbreak occurred, and 17 patients became infected or colonized with the epidemic strain. Reservoirs appeared to be patients who were infected or colonized with the resistant S aureus and possibly two nurses who were nasal carriers. The outbreak isolate was likely spread by contact with contaminated hands of personnel. A retrospective case-control study identified tracheostomy, débridement, and irrigation of wounds by power spray and prolonged nasogastric intubation as risk factors for acquisition of the epidemic strain. Analysis of factors by groups indicated that surgical procedures, wound care procedures and instrumentation of the respiratory tract were significantly associated with cases. The nasal carrier state was eradicated in two nurses by topical application of 5% vancomycin. The epidemic strain was eradicated from the hospital 8 months after it was introduced.

Carrier State↗
PubMed1986

Types of disposable medical devices reused in hospitals.

Rising health care costs have prompted hospitals to turn to reprocessing and reuse of disposable devices as a cost-saving measure. The safety, efficacy, and cost benefit of such a practice are largely unknown. Classification schemata are presented as a means of categorizing the reasons for reprocessing and the types of adverse effects that may result from reprocessing and reuse. The very limited literature on reuse of disposable devices is reviewed. Examples of the categories of reprocessing and adverse effects are provided from a review of the experience with reprocessing and reuse at a university medical center. With the rising pressure for containment of health care costs, it is likely that this practice will expand further. The practice of reprocessing and reuse should be subjected to scientific study.

Disposable Equipment↗
PubMed1986

Prospective study of catheter replacement and other risk factors for infection of hyperalimentation catheters.

To determine risk factors for infection of hyperalimentation catheters, we prospectively studied 169 catheter systems (88 patients) by using a semiquantitative culture technique. Infection occurred in 24 (14%) catheters (16 patients), was inversely proportional to the number of previous catheters inserted by the operator (P less than .02), and was proportional to the interval between admission and catheter insertion (P less than .0005). Catheter replacement over a guidewire was no more likely to be associated with infection than was a de novo percutaneous insertion at another site (P = .6). Using a proportional hazards model, we estimated the risk of infection per day to be 1.3 times greater for a catheter if the patient had been hospitalized 50 days instead of seven days, and 3.8 times greater if the patient had a Swan-Ganz catheter at the time of insertion.

Adult↗
PubMed1984

Ventriculostomy-related infections. A prospective epidemiologic study.

We concluded a prospective epidemiologic study of ventriculostomy-related infections (ventriculitis or meningitis) in 172 consecutive neurosurgical patients over a two-year period to determine the incidence, risk factors, and clinical characteristics of the infections. Ventriculitis or meningitis developed in 19 of 172 patients (11 per cent) undergoing a total of 213 ventriculostomies. When data from all these cases plus five cases of nonventriculostomy-related infection were combined, cerebrospinal-fluid pleocytosis was more significantly associated with the diagnosis of ventriculitis or meningitis (P less than 0.0001) than were fever and leukocytosis (P = 0.07). Risk factors for ventriculostomy-related infections included intracerebral hemorrhage with intraventricular hemorrhage (P = 0.027), neurosurgical operations (P = 0.016), intracranial pressure of 20 mm Hg or more (P = 0.019), ventricular catheterization for more than five days (P = 0.017), and irrigation of the system (P = 0.021). Previous ventriculostomy did not increase the risk of infection with subsequent procedures. We conclude that ventriculostomy-related infections may be prevented by maintenance of a closed drainage system and by early removal of the ventricular catheter. If monitoring is required for more than five days, the catheter should be removed and inserted at a different site.

Bacteria↗
PubMed1984

Streptococcus faecium outbreak in a neonatal intensive care unit.

An outbreak of bacteremia and meningitis in a neonatal intensive care unit is described. Seven cases occurred in premature infants with severe underlying diseases. An epidemiological investigation failed to document the reservoir of the epidemic strain but suggested that its transmission among the infants was via the hands of hospital personnel. All patients had nasogastric tubes and multiple intravascular devices, and the portal of entry may have been either the gastrointestinal tract or the sites of the intravascular devices. Conventional biotyping of isolates failed to differentiate between isolates from infected patients and isolates recovered from prevalence surveys and from the environment. However, rapid identification systems (API-20S [Analytab Products, Plainview, N.Y.] and the AutoMicrobic system [Vitek Systems, Inc., Hazelwood, Mo.]) were able to distinguish isolates recovered from infected patients and hands of hospital personnel from isolates recovered during prevalence and environmental surveys and 29 isolates from widespread geographical areas. This is the first known report of a nosocomial neonatal outbreak of bacteremia and meningitis due to Streptococcus faecium; it underscores the importance of identifying streptococci to species level.

Cross Infection↗
PubMed1984

Outbreak of Salmonella typhimurium gastroenteritis due to an imported strain resistant to ampicillin, chloramphenicol, and trimethoprim-sulfamethoxazole in a nursery.

An outbreak caused by a highly resistant strain of Salmonella typhimurium occurred in a nursery at a university medical center. The outbreak strain, which was resistant to ampicillin, chloramphenicol, and trimethoprim-sulfamethoxazole, was apparently imported from the Far East by a Cambodian refugee. The five patients involved had severe underlying diseases, and bacteremia and meningitis developed in one of these patients. The only reservoir identified was the gastrointestinal tracts of the infected patients, and infection was probably transmitted by the contaminated hands of hospital personnel. The outbreak was rapidly brought under control by isolating cases outside of the nursery and by instituting enteric precautions for infants who remained in the nursery. When compared by disk diffusion susceptibility tests with 353 strains of S. typhimurium tested at the Centers for Disease Control, the imported strain had a unique antibiogram. Bacteriophage typing of the strains revealed that all were untypable; this, in itself, was a good marker, because only 5 to 10% of S. typhimurium isolates in this country have this property. Agarose gel electrophoresis of isolates from the five patients revealed an identical plasmid banding pattern consisting of three large and three small plasmids. Highly resistant strains of S. typhimurium imported from the Far East may spread rapidly when introduced into a hospital nursery. Prompt institution of control measures may limit the outbreak and prevent systemic infections for which there are few effective therapeutic agents.

Ampicillin↗
PubMed1984

Sequential ventricular fluid concentrations of ceftazidime--report of three cases.

Three adult subjects, each with a ventriculostomy, received ceftazidime 2g iv q8h for three doses. Serial samples of serum and CSF ventricular fluid were obtained following the third dose; ceftazidime concentrations were measured by high pressure liquid chromatography. In one patient without inflammatory cells in the CSF, ceftazidime CSF concentrations were only approximately 0.3 micrograms/ml. In two other patients who had inflammatory cells and blood in the CSF, concentrations of ceftazidime in ventricular fluid demonstrated a slow rise and decline over an eight-hour period. Although contamination of the CSF by blood in these two patients confounds the interpretation of the concentrations achieved, it is concluded that obtaining serial samples of CSF from a ventriculostomy offers a more realistic appraisal of the dynamics of antibiotic penetration compared with the single-point method.

Adult↗
PubMed1983

Gentamicin and tobramycin penetration into burn eschar. Pharmacokinetics and microbiological effects.

This study was designed to determine whether intravenously administered gentamicin sulfate and tobramycin sulfate penetrate into the eschar of patients with severe burns. In addition, each antibiotic's pharmacokinetics in serum and the effect on eschar microbiology were determined. Twenty patients with suspected burn wound sepsis received either gentamicin or tobramycin. The microbiology of the baseline eschar was determined and repeated on days 2, 4, and 7. All patients had measurable aminoglycoside tissue concentrations, and elimination from serum was not unusually rapid. Thirteen patients had baseline eschar cultures positive for Pseudomonas aeruginosa or Serratia marcescens; eight patients were initially bacteremic. Pseudomonas aeruginosa strains were sensitive to both antibiotics and usually declined in concentration with time or were eliminated; the more drug-resistant isolates of S marcescens persisted or caused super-infection and bacteremia. Aminoglycoside antibiotics penetrate into burn eschar and appear to have a substantial effect on eschar microbiology.

Adolescent↗
PubMed1983

Comparison of epidemiological markers used in the investigation of an outbreak of methicillin-resistant Staphylococcus aureus infections.

An outbreak of nosocomial infections was caused by a single strain of methicillin-resistant (MR) Staphylococcus aureus. This strain was followed as it was transmitted from the index case to 17 patients, 3 hospital personnel, and 12 items in the hospital environment. The MR S. aureus strain was traced by using four specific epidemiological markers: antibiogram, phage type, production of aminoglycoside-inactivating enzymes, and plasmid pattern. These markers were assessed for their reliability in differentiating the epidemic S. aureus strain from resident nonepidemic strains and for the ease and rapidity with which they determined differences. The epidemic strain was resistant to beta-lactam antibiotics, gentamicin, erythromycin, clindamycin, and rifampin. Resistance to rifampin was the only unique marker in the antibiogram which distinguished the epidemic strain from the indigenous strains, and it was the easiest marker to use for screening isolates from culture surveys. Phage typing was poorly reproducible and did not yield results rapidly enough to be useful for ongoing epidemiology. The epidemic strain produced a unique aminoglycoside-inactivating enzyme (3'-phosphotransferase) which distinguished it from indigenous gentamicin-resistant staphylococci, but this marker was not easily identified, nor was identification helpful during the course of the investigation. Plasmid pattern analysis was rapidly performed (in less than 24 h), allowed many isolates to be examined at a time, was stable and reproducible, and yielded a unique fingerprint which distinguished the epidemic strain from all indigenous isolates. Plasmid pattern analysis is a promising epidemiological tool for MR S. aureus outbreaks in which epidemic strains lack unique antibiotic resistance markers.

Bacteriophage Typing↗
PubMed1983

Contralateral hydrothorax following subclavian catheter replacement using a guidewire.

Replacement of central venous catheters over a guidewire is now practiced throughout the United States. Although potential mechanical complications of this technique have been mentioned in the literature, few such complications have been documented. We report a patient who suffered a fatal contralateral hydrothorax following replacement of a central venous catheter using the guidewire technique.

Adult↗