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A M Yinnon

Publications and source records attributed to A M Yinnon.

At least 19 recordsLinked to original sources
PubMed2006

Prospective drug utilization evaluation of three broad-spectrum antimicrobials: cefepime, piperacillin-tazobactam and meropenem.

BACKGROUND: Cefepime, piperacillin-tazobactam and meropenem are among the broadest-spectrum and most expensive antimicrobials. AIM: To evaluate guidelines for appropriate use of these drugs. METHODS: We developed guidelines for use of these antibiotics, and conducted a two-phase drug utilization evaluation. We included all patients who received one of the study drugs during two 3-month periods, with an educational intervention in the intervening period. Appropriateness was determined for initiation of treatment, and for adaptation or continuation of established treatment. RESULTS: Overall, 205 patients received 271 courses with one of these antibiotics, for a total of 709 defined daily doses (DDD) of cefepime, 543 of piperacillin-tazobactam, and 680 of meropenem (8.3, 6.3 and 7.9 DDD/1000 admission days, respectively). Of these 271 courses, 234 were appropriate (86%). Treatment was continued for > or =5 days in 60%, of which 88% were appropriate (NS). Of the 271 courses, 210 (77%) were empirical (83% appropriate), while 61 (23%) were based on a relevant culture result (97% appropriate) (p < 0.001). Appropriateness differed significantly between departments (p < 0.001), and between the two phases (p < 0.001). The major difference between the two surveys was a decrease in meropenem usage (p < 0.05). DISCUSSION: The vast majority of courses with cefepime, piperacillin-tazobactam and meropenem are empirically selected and continued, underlying the importance of an optimal initial choice. Antibiotic guidelines, in conjunction with formal infectious disease consultation, can contribute to more appropriate use of these drugs.

Anti-Bacterial Agents↗
PubMed2006

Risk factors for bacteriuria due to Pseudomonas aeruginosa or Enterococcus spp in patients hospitalized via the emergency department.

To determine the incidence and risk factors related to isolation of Pseudomonas aeruginosa or Enterococcus spp from urine cultures obtained from patients in the emergency department (ED), a 1-year prospective study was conducted of all urine specimens collected in the ED of a general hospital. Specimens from which one of these organisms was isolated at a concentration of >or=10(5) cfu/ml were included. Of 744 positive urine cultures, 39 (5%) were P. aeruginosa and 28 (4%) Enterococcus spp. Comparison with a control cohort of 80 patients with Escherichia coli bacteriuria revealed several univariate indicators for P. aeruginosa bacteriuria, including male sex, indwelling catheter, past prostatectomy, hospitalization in the previous 2 months and pregnancy; multivariate indicators were indwelling catheter (p<0.001) and male sex (p<0.001). Enterococcus and P. aeruginosa were significantly more often associated with asymptomatic bacteriuria. These data will help clinicians select appropriate antibiotic treatment for patients with urinary tract infections.

Bacteriuria↗
PubMed2006

Assessment of the clinical significance of production of extended-spectrum beta-lactamases (ESBL) by Enterobacteriaceae.

BACKGROUND: We conducted a retrospective, cohort-controlled study to evaluate the effect of extended-spectrum beta-lactamase (ESBL) production by Enterobacteriaceae isolated from blood cultures, and of third or fourth generation cephalosporin treatment, on outcome. METHODS: Four hundred and fifty patient-unique Enterobacteriaceae, isolated from blood cultures during 2000 (before routine ESBL testing was introduced), were tested for ESBL by double-disk method and by E-test, assessing cefotaxime, ceftazidime and cefpodoxime, with and without clavulanate. Cases consisted of ESBL-positive (+) samples, originally reported as ceftazidime-susceptible; controls were ESBL-negative (-). Patient records were extensively reviewed. RESULTS: We identified 68 Enterobacteriaceae that were ESBL(+); they were compared with 186 ESBL(-) control organisms. Patients with sepsis due to an ESBL(+) organism more often had nosocomial infection, resided in nursing homes, were functionally dependent, had an indwelling catheter, had Klebsiella, and had a lower serum albumin level (all p < 0.001). Survival of patients with ESBL(+) and ESBL(-) sepsis was, respectively, 71% and 84% (p < 0.05). Multivariate analysis revealed that the only independent risk factor for death was a low serum albumin. Neither empiric nor definite treatment with cephalosporins was found to be an independent risk factor for death. Subset analysis was conducted on 15 patients with ESBL(+) sepsis and 21 controls with ESBL(-) sepsis, who had been treated with ceftazidime or cefepime only. In this subset, ESBL(+) patients more often resided in nursing homes (< 0.05), they had a significantly lower APACHE-II score (< 0.01) and the infection was more often nosocomial (< 0.005). Survival of ESBL(+) and ESBL(-) patients was 67% and 71%, respectively (NS). Time till defervescence did not differ between cases and controls. CONCLUSION: Mortality of patients with ESBL(+) sepsis was higher than that of patients with ESBL(-) sepsis. The reason appears to be related to other factors rather than to empiric treatment with cephalosporins or the nature or resistance pattern of the organism. This, at least, appears to be the case for patients with urosepsis, who constituted the majority of patients in this study.

Adult↗
PubMed2006

Group A streptococcus bacteraemia: comparison of adults and children in a single medical centre.

Group A streptococcus (GAS) bacteraemia is often associated with soft-tissue infection, with significant morbidity and mortality. Little is known concerning the differences between adults and children with GAS bacteraemia. Records for 98 of 116 cases of GAS bacteraemia (60 adults and 38 children, aged 7 days to 96 years) occurring during a 10-year period (1993-2002) were located and reviewed. GAS bacteraemia comprised 0.6% of all bacteraemias in adults, compared to 3.3% in children (p < 0.001). The rate of adult GAS bacteraemia was two cases/1000 hospitalisations, compared to 13/1000 in children (p < 0.001). Seventy-six (78%) patients had concomitant tissue involvement, with skin or soft-tissue infection being the most common (62%). Fifty-three (88%) of 60 adults and five (13%) of 38 children had underlying conditions (p < 0.001). Twelve patients died, only one of whom was a child. Parameters associated with mortality were older age, lower temperature, hypotension, a need for surgical intervention, toxic shock syndrome, disseminated intravascular coagulation, thrombocytopenia, lymphopenia, hypocalcaemia, renal failure and acidosis (p < 0.05).

Academic Medical Centers↗
PubMed2005

Prospective hospital-wide studies of 505 patients with nosocomial bacteraemia in 1997 and 2002.

We conducted surveys in 1997 and 2002 to determine the rate, underlying sources and outcome of nosocomial bacteraemia. Blood culture results were reviewed daily. All patients with positive cultures drawn >or=48 h after hospitalization were included in the study and their charts were reviewed. The underlying source of infection was determined by pre-defined clinical and/or microbiological criteria. Patients were followed until discharge or death. In 1997 and 2002, 851 and 857 patient-unique cases of bacteraemia were diagnosed, respectively, excluding contaminants; of these, 228 (27%) and 277 (32%) cases, respectively, were hospital acquired (P<0.05). The overall rate decreased from 7.5 to 7.0 per 1,000 admissions (P<0.001). The sources of bacteraemia in 1997 and 2002, respectively, were: intravascular catheters (36% and 27%, P<0.05), urinary tract (8% and 15%, P<0.05), respiratory tract (5% and 13%, P<0.01) and surgical sites (14% and 4%, P<0.001). In one-third of patients, the source of bacteraemia could not be determined. Only 52% and 54%, respectively, of these patients were discharged alive (difference was not significant). In 1997, Staphylococcus aureus was the most frequent isolate (26%), followed by coagulase-negative Staphylococcus (13%) and Klebsiella pneumoniae (11%). By 2002, the incidence of S. aureus had fallen to 11% (P<0.001), acinetobacter was the single most frequently isolated organism (increased from 6% to 17%) (P<0.001). In-hospital mortality associated with acinetobacter bacteraemia (57%) was significantly higher than that for other organisms (31-43%) (P<0.05). In conclusion, prospective surveys of nosocomial bacteraemias provide valuable information, facilitating the pursuit of successful interventions.

Acinetobacter↗
PubMed2005

Demographic and clinical characteristics of patients admitted to medical departments.

INTRODUCTION: The significant changes, which have affected departments of medicine over the last two decades, have been much editorialized. Surprisingly few data have been published that document these changes. We describe the demographic and clinical characteristics of patients admitted to one hospital's departments of internal medicine. METHODS: During a 3 months prospective study, 1039 patients (46% of all 2277 new admissions to the departments of medicine, consisting of +/- 175 beds) were randomized for inclusion. Information was extracted from the medical records regarding demography; functional capacity; clinical data and outcome. RESULTS: The mean age of the patients was 72 +/- 16 years (mean +/- SD); 51% were male, 56% were married, and 83% lived at home. Although 293 patients (28%) were defined as dependent, the majority lived at home (170, 58%). Cognition was normal in only 74%. The four most common disease categories leading to admission were infections (383 patients, 37%), cardiovascular disorders (372, 36%), respiratory conditions (284, 27%) and genito-urinary problems (90, 9%). Overall, 98 persons died (9%). Independent risk factors for death were: mechanical ventilation; a 'do not resuscitate' order; a high APACHE-II score; a low serum albumin level; higher age; and not being married (P < 0.01). CONCLUSIONS: Geriatric patients occupy a central position in our medical wards. These data are relevant for allocation of special resources for departments with high proportions of geriatric patients; for the design of employment conditions that ascertains continuing job satisfaction; as well as for the planning of teaching opportunities for residents and students.

Age Factors↗
PubMed2005

Non-Typhi Salmonella gastroenteritis in children presenting to the emergency department: characteristics of patients with associated bacteraemia.

The records of children with Salmonella gastroenteritis only (n = 97), and those with associated bacteraemia (n = 64), seen in one medical centre during a 12-year period, were analysed retrospectively. Mean patient age was 2.24 +/- 2.8 years (range, 0.05-16 years), and 49% were male. Children with bacteraemia presented after a longer duration of symptoms (7.0 +/- 6.9 vs. 3.9 +/- 4.6 days, p 0.0002), and had higher erythrocyte sedimentation rates (45 +/- 22 vs. 33 +/- 22 mm/h, p < 0.02) and lactate dehydrogenase values (924 +/- 113 vs. 685 +/- 165 IU/L, p 0.001). There was a trend in bacteraemic children towards immunosuppression (6.3% vs. 1.0%, p 0.08) and a lower number of siblings (2.9 +/- 1.9 vs. 3.8 +/- 2.7, p 0.063). Non-bacteraemic children had a more severe clinical appearance, and a higher percentage had a moderate to bad general appearance (51.5 vs. 29.7%, p < 0.01), with dehydration (37.1 vs. 18.8%, p 0.02) and vomiting (58.8 vs. 39.0%, p 0.02). Laboratory dehydration indicators were also markedly worse in non-bacteraemic children, with urine specific gravity of 1020 +/- 9.4 vs. 1013 +/- 9.0 (p 0.0002), base excess of - 4.2 +/- 3.0 vs. - 2.5 +/- 3.4 mEq/L (p 0.01), and blood urea nitrogen of 10.1 +/- 7.0 vs. 7.4 +/- 4.5 mg% (p 0.002). Thus, the clinical presentation of bacteraemic children was more gradual, and associated gastroenteritis and dehydration was less pronounced. These findings may contribute in part to the inadvertent discharge of bacteraemic children from the emergency department.

Adolescent↗
PubMed2003

Use of time-trend analysis in the design of empirical antimicrobial treatment of urinary tract infection.

Selection of empirical treatment of hospitalized patients with urinary tract infection (UTI) is usually based on the results of urine culture as obtained from the local microbiology laboratory. In order to improve the precision and reliability of traditional methods, we analyzed temporal changes in the results of urine culture and antibiograms and stratified the results by inpatient department and the presence/absence of an indwelling catheter. The database consisted of urine cultures obtained during the first 3 months of each year over a 10-year period between 1991 and 2000. Only urine samples that grew a single organism at a concentration of >10(5) cfu were included in the analysis. Trend statistical tools, readily available but thus far not used for microbiological analyses, were applied to assess the decay in activity of individual antibiotic agents over time and to calculate susceptibility rates of organisms in subsets of urine samples. Organisms, antimicrobial susceptibility rates and the degree of decay in antimicrobial susceptibility rates varied significantly according to the location of the patient in the hospital and the presence of an indwelling catheter. Stratified trend analysis is a useful tool that can be helpful in designing and adapting clinical guidelines for the selection of appropriate empirical antibiotic treatment for the individual patient with urinary tract infection.

Anti-Bacterial Agents↗
PubMed2003

Susceptibility trends in bacteraemias: analyses of 7544 patient-unique bacteraemic episodes spanning 11 years (1990-2000).

The aim of the present study was to design more accurate tools for the selection of appropriate antimicrobial therapy for hospitalized patients with suspected sepsis. We created a large database comprising data on all patient-unique blood cultures obtained over an 11 year period (1 January, 1990 through 31 December, 2000). Improved statistical tools were applied to assess the trends in in vitro activity of individual antibiotic agents against various bacteria over time, and to calculate susceptibility rates of subsets of organisms. During the 11 year study period, 173571 blood cultures were obtained, of which 17703 (10.2%) were positive, with 7544 patient-unique blood cultures (4.3%). The mean annual number of positive, patient-unique cultures was 686 (standard deviation=79). The 10 most frequently isolated organisms were: Escherichia coli (1494), Staphylococcus aureus (1240), Klebsiella pneumoniae (779), Enterococcus spp. (631), Pseudomonas aeruginosa (488), Streptococcus pneumoniae (447), Enterobacter spp. (338), Acinetobacter spp. (298), Proteus mirabilis (260) and Candida spp. (254). No significant change was detected in the annual rates (means, standard deviations) per 1000 admissions of these organisms: the highest was E. coli (5.5, 1), the lowest was Candida (1, 0.3). Forty percent of organisms (N=2943) were obtained from patients in the emergency department (ED), 23% (1744) in medical departments, 15% (1134) in paediatric units, 13% (998) on surgical wards and 9% (709) in intensive care units (ICUs). Trend statistical analysis revealed a significant decrease in susceptibility in ED Enterobacteriaceae to eight of 15 (53%) tested antimicrobials, with a mean annual decrease of 1.6%+/-0.6%, in the ICU isolates, a significant decrease was detected in only five (33%) of the tested antimicrobials, with a mean annual decrease of 2.5%+/-1.3%. The difference in susceptibility between ED and ICU isolates was significant for all antimicrobials (P<0.001). A significant decrease in the susceptibility of E coli to nine of 15 drugs (60%) was detected, ranging from 0.7% to 2.7% annually. In K. pneumoniae a significant decrease in susceptibility of K. pneumoniae was detected with only two agents. Pseudomonas spp. isolates remained highly sensitive to all traditional anti-pseudomonal agents, without significant decay in sensitivity rates over time. Susceptibility of S. aureus to methicillin decreased significantly for several subsets of patients (P<0.001). Marked differences in susceptibility rates between the departments were detected. Trend statistical analyses, when appropriately applied to multi-year databases of microbial susceptibilities, may yield susceptibility tables that are significantly more accurate than traditional semi-annual or annual tables.

Anti-Bacterial Agents↗
PubMed2002

Changing epidemiology of infective endocarditis: a retrospective survey of 108 cases, 1990-1999.

The aim of this study was to report the experience with infective endocarditis over the past decade, describe the changing clinical and epidemiological features of the disease, and attempt to determine the optimal number of blood culture sets required for diagnosis. All cases diagnosed during a 10-year period were reviewed clinically and microbiologically. In addition, a retrospective assessment of blood culture data was performed. From the period 1990-1999, 108 cases that met the von Reyn or Duke's criteria were recorded. The major underlying cardiac condition was the presence of a prosthetic valve ( n=33 patients, 31%). Among patients with native valves, nonrheumatic valvular heart disease of the elderly was the most common underlying factor ( n=19 patients, 25%). Overall, 13 patients (11%) died. Predictors on admission for increased mortality were shortness of breath, age >60 years, time to defervescence, erythrocyturia, hemoglobin level <10 g/dl, and leukocytosis >15,000 (all P<0.05). Analysis of blood culture data showed that the diagnostic yield among groups from whom either only one or more than six blood culture sets were drawn was reduced compared with that among groups from whom between two and five culture sets had been taken. The outcome of endocarditis in this series from a community hospital was much more favorable compared with that reported in surveys from large tertiary centers. Moreover, obtaining more than two or three blood cultures is neither helpful nor cost-effective in the initial assessment of patients with suspected endocarditis.

Aged↗
PubMed2002

Risk factors for nephrotoxicity in elderly patients receiving once-daily aminoglycosides.

BACKGROUND: There remain concerns about the safety of once-daily dosing of aminoglycosides (AGs) in the elderly. AIM: To assess the safety of once-daily AGs in elderly patients and evaluate possible risk factors for nephrotoxicity. DESIGN: Prospective, non-interventional surveillance study. METHODS: All patients receiving AGs were monitored over 4 months. Clinicians determined the AG dose for each patient after estimating patient weight and calculating creatinine clearance (CrCl) using the Cockcroft-Gault formula. Parallel figures were calculated by the investigators using measured weight. Clinicians obtained an AG trough level 24 h after initiation of treatment, and, if non-toxic, every 5-7 days thereafter. AG toxicity was defined as an increase in serum creatinine of > or =50%. RESULTS: In the study period, 249 consecutive patients received an AG: 116 (47%) males, mean+/-SD age 75+/-16 years. Forty-two (17%) received amikacin and 207 (83%) gentamicin. An increase of > or =50% in serum creatinine was detected in 31/249 (12.4%); maximal creatinine was < or =177 micromol/l in 16/249 (6.4%), 186-265 micromol/l in nine (3.6%), and >265 micromol/l in six (2.4%). None developed oliguric renal failure. Renal damage correlated with a high AG trough level (>1.1 microg/ml) (p<0.001); haemoglobin level <10 g/dl (p<0.05); hospital admission >7 days prior to AG treatment (p<0.005); and AG treatment > or =11 days (p<0.05). Mean CrCl based on estimated weight was 52+/-18 ml/min; that based on actual weight was 71+/-37 ml/min. Despite this, mean AG dose was 1.3+/-0.6 higher than optimal. CONCLUSIONS: Oliguric and/or lasting renal toxicity is rare in elderly patients receiving once-daily aminoglycosides for <11 days, if regular trough drug levels are monitored.

Adult↗
PubMed2001

Whither infectious diseases consultations? Analysis of 14,005 consultations from a 5-year period.

During a 5-year period, data from all infectious disease (ID) consultations were recorded in a computerized database, which included 9068 new and 4937 additional consultations. The purpose of these 14,005 consultations was therapy (for 58%), diagnosis (for 13%), both (for 24%), and prophylaxis (for 4%); 51% were performed at the bedside, and the remainder were by discussion (19%) or telephone (30%). Recommendations included the following: initiation, change, or discontinuation of antibiotics (in 46%); performance of diagnostic tests (in 20%) or surgical procedures (in 1%); prophylaxis (in 3%); or no change (in 29%). Analysis of new versus additional consultations revealed significant differences. A new ID consultation was given at a rate of 6.0 consultations per 100 hospitalized patients; the rate per department correlated with the expenditure on antimicrobials per patient admission. During the study period, expenditure on antimicrobials per admission steadily decreased, from $44 in 1995 to $30 in 1999, a 35% reduction. In conclusion, analysis of data from ID consultations enables the ID service to evaluate its activity and to direct efforts to departments with high rates of nosocomial infections, antimicrobial resistance, and/or antimicrobial use.

Anti-Infective Agents↗
PubMed2001

Adult patients with occult bacteremia discharged from the emergency department: epidemiological and clinical characteristics.

To determine the epidemiological and clinical characteristics of patients who were discharged from the emergency department (ED) and subsequently proved to have bacteremia, we prospectively assessed all patients examined in the ED during an 18-month period from whose blood cultures a significant organism was isolated. Discharged patients were contacted and reevaluated. Two case-control studies were conducted, in which each study patient was matched with a total of 4 control patients. During the study period, 46,336 patients were examined in the ED; 78% were adults and 22% were children. Blood cultures were performed for 25% of the adult patients and for 44% of the children. Although the occurrence of occult bacteremia in patients who were discharged from the ED is 3.7 times more common in children than in adults, the absolute numbers of discharged adults and children with occult bacteremia are similar. Careful clinical assessment will not prevent discharge of some of these patients; however, these patients in general do well and can be safely recalled for reevaluation and complementation of therapy.

Adolescent↗