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G R Corey

Publications and source records attributed to G R Corey.

At least 37 records · Page 2Linked to original sources
PubMed2000

Clinical information determines the impact of transesophageal echocardiography on the diagnosis of infective endocarditis by the duke criteria.

BACKGROUND: Although transesophageal echocardiography (TEE) is more sensitive than transthoracic echocardiography (TTE) in detecting echocardiographic evidence of infective endocarditis (IE), the impact of TEE on the clinical diagnosis of IE has not been clearly delineated. METHODS AND RESULTS: We studied 112 patients with 114 suspected episodes of IE over a 6-year period who underwent both TTE and TEE during their diagnostic evaluation. Using the results of these studies along with clinical and microbiologic data, we attempted to determine the incremental value of TEE to the Duke Endocarditis Diagnostic Criteria. Patients were initially classified into a diagnostic category of the Duke criteria with TTE data, and then the diagnostic classification was reconsidered with TEE data. A diagnostic category reassignment occurred in 25 of 114 episodes of IE evaluated when TEE results were incorporated into the evaluation with the Duke criteria (22 patients were reclassified from possible IE to definite IE whereas 3 patients were reclassified from rejected to possible IE). Diagnostic reclassification occurred in 9 (11%) of the 80 episodes of suspected IE with native cardiac valves and 13 (34%) of 34 episodes with prosthetic cardiac valves. Most patients reclassified from possible IE to definite IE with TEE data (19 of 22) had an intermediate clinical likelihood of IE, whereas 92% of patients had negative TTE results. Pathologic examination of valvular tissue in 22 of the 114 episodes of suspected IE revealed that the positive predictive value of the Duke criteria with TEE data for diagnosis of IE was 85% in patients with native valves and 89% in patients with prosthetic valves. CONCLUSIONS: When clinical evidence of IE is present, TEE improves the sensitivity of the Duke criteria to diagnose definite IE. TEE data appears to be especially useful for the diagnostic evaluation of patients with suspected IE who have prosthetic valves.

Diagnosis, Differential↗
PubMed2000

Prospective analysis of Staphylococcus aureus bacteremia in nonneutropenic adults with malignancy.

PURPOSE: To determine the primary sources and secondary complications of Staphylococcus aureus bacteremia (SAB) in cancer patients, as well as predictors of outcome in cancer patients with SAB. PATIENTS AND METHODS: Fifty-two patients at Duke University Medical Center met entry criteria between September 1994 and December 1996 for this prospective cohort study involving hospitalized nonneutropenic adult cancer patients with SAB. All subjects were observed throughout initial hospitalization and were evaluated again at 6 and 12 weeks or until death. RESULTS: SAB was intravascular device-related in 42%, tissue infection-related (TIR) in 44%, and unidentifiable focus-related (UFR) in 13%. Seventeen patients (33%) were found to have metastatic infections or conditions, with eight (15%) developing infectious endocarditis (IE). Patients with TIR bacteremia were less likely than other patients to develop IE (4% v 24%, P =.06). The overall mortality rate was 38%, the SAB-related mortality rate was 15%, and the rate of SAB relapse was 12%. Methicillin resistance was not associated with adverse outcome. Inability to identify a point of entry (UFR bacteremia), however, was associated with a higher overall mortality rate (100% v 24%, P =.0006). Furthermore, a 72-hour surveillance blood culture positive for organisms was associated with an increased incidence of IE (P =.0006), metastatic infections or conditions (P =.0002), SAB relapse (P =.038), and SAB-related death (P =.038). CONCLUSION: SAB in cancer patients is associated with significant morbidity from frequent metastatic infections or conditions including IE, as well as considerable mortality. Unknown initial infection site and 72-hour surveillance cultures positive for organisms were predictive of a complicated course and poor final outcome.

Adolescent↗
PubMed1999

Cost-effectiveness of transesophageal echocardiography to determine the duration of therapy for intravascular catheter-associated Staphylococcus aureus bacteremia.

BACKGROUND: The appropriate duration of therapy for catheter-associated Staphylococcus aureus bacteremia is controversial. Conventional practice dictates that all patients receive prolonged courses of intravenous antibiotics. Some clinicians recommend abbreviated therapeutic courses, but an alternate approach involves prospectively identifying patients for whom abbreviated therapy is appropriate. OBJECTIVE: To determine the cost-effectiveness of transesophageal echocardiography (TEE) in establishing duration of therapy for catheter-associated S. aureus bacteremia. DESIGN: Cost-effectiveness analysis. DATA SOURCES: MEDLINE search of literature; clinical data from patients with S. aureus bacteremia (n = 196) and patients with endocarditis (n = 60); and costs obtained from the study institution, regional home health agency, and national estimates of professional and technical fees. TARGET POPULATION: Patients with catheter-associated S. aureus bacteremia on native heart valves without intravenous drug use or clinically apparent metastatic infection, immunosuppression, or indwelling prosthetic devices. TIME HORIZON: Patient lifetime. PERSPECTIVE: Societal. INTERVENTIONS: Antibiotic treatment based on TEE results compared with 2- or 4-week empirical therapy. OUTCOME MEASURES: Quality-adjusted life expectancy, costs, and incremental cost-effectiveness ratios. RESULTS OF BASE-CASE ANALYSIS: Compared with empirical short-course therapy, the TEE strategy cost $4938 per quality-adjusted life-year (QALY) gained. The effectiveness of the TEE strategy and the effectiveness of the long-course strategy were sufficiently similar that the additional cost of empirical long-course therapy ($1,667,971 per QALY) was higher than that which society usually considers cost-effective. RESULTS OF SENSITIVITY ANALYSES: In a four-way sensitivity analysis (endocarditis prevalence, TEE cost, short-course relapse rate, and TEE specificity), compared with empirical short-course therapy, the TEE strategy results ranged from cost savings to $155,624 per QALY. CONCLUSION: Within the limitations of existing empirical data, this study suggests that for patients with clinically uncomplicated catheter-associated S. aureus bacteremia, the use of TEE to determine therapy duration is a cost-effective alternative to 2- or 4-week empirical therapy.

Anti-Bacterial Agents↗
PubMed1999

Recurrent Staphylococcus aureus bacteremia: pulsed-field gel electrophoresis findings in 29 patients.

To identify risk factors for relapse among 309 prospectively identified cases of Staphylococcus aureus bacteremia, patients with recurrent S. aureus bacteremia were identified, and pulsed-field gel electrophoresis (PFGE) was performed on isolates from both episodes. PFGE banding patterns from both isolates were identical in 23 patients, consistent with relapsed infection. Patients with PFGE-confirmed relapse were more likely by both univariate and multivariate analyses to have an indwelling foreign body (odds ratio [OR]=18.2, 95% confidence interval [CI]=7. 6-43.6; P<.001), to have received vancomycin therapy (OR=4.1, 95% CI=1.5-11.6; P=.008), or be hemodialysis-dependent (OR=4.1, 95% CI=1. 8-9.3; P=.002) than patients who did not develop recurrent bacteremia. These results suggest that recurrent episodes of S. aureus bacteremia are primarily relapses and are associated with an indwelling foreign body, receiving vancomycin therapy, and hemodialysis dependence.

Adult↗
PubMed1999

The incidence of ehrlichial and rickettsial infection in patients with unexplained fever and recent history of tick bite in central North Carolina.

We examined the clinical and laboratory findings of a consecutive series of patients from central North Carolina presenting with fever and a history of tick bite within the preceding 14 days. Evidence of a tick-transmitted pathogen was detected in 16 of 35 patients enrolled over a 2-year period. Nine patients were infected with Ehrlichia chaffeensis, and 6 were infected with a spotted fever group rickettsia; 1 patient had evidence of coinfection with E. chaffeensis and a spotted fever group rickettsia. Four patients had detectable antibodies against the human granulocytic ehrlichiosis agent; however, only 2 had a 4-fold antibody titer rise without detectable antibodies against E. chaffeensis. The other 2 were thought to have cross-reacting antibodies to E. chaffeensis. We conclude that ehrlichial infections may be as common as spotted fever group rickettsial infections in febrile patients from central North Carolina with a recent history of tick bite.

Adult↗
PubMed1999

Infective endocarditis due to Staphylococcus aureus: 59 prospectively identified cases with follow-up.

Fifty-nine consecutive patients with definite Staphylococcus aureus infective endocarditis (IE) by the Duke criteria were prospectively identified at our hospital over a 3-year period. Twenty-seven (45.8%) of the 59 patients had hospital-acquired S. aureus bacteremia. The presumed source of infection was an intravascular device in 50.8% of patients. Transthoracic echocardiography (TTE) revealed evidence of IE in 20 patients (33.9%), whereas transesophageal echocardiography (TEE) revealed evidence of IE in 48 patients (81.4%). The outcome for patients was strongly associated with echocardiographic findings: 13 (68.4%) of 19 patients with vegetations visualized by TTE had an embolic event or died of their infection vs. five (16.7%) of 30 patients whose vegetations were visualized only by TEE (P < .01). Most patients with S. aureus IE developed their infection as a consequence of a nosocomial or intravascular device-related infection. TEE established the diagnosis of S. aureus IE in many instances when TTE was nondiagnostic. Visualization of vegetations by TTE may provide prognostic information for patients with S. aureus IE.

Adult↗
PubMed1999

Failure of amphotericin B colloidal dispersion in the treatment of paracoccidioidomycosis.

Although amphotericin B desoxycholate is considered the most effective treatment for disseminated Paracoccidioides brasiliensis infections, little is known about the efficacy of lipid-based formulations of amphotericin B in this infection. In this study, we treated four adults with the juvenile form of paracoccidioidomycosis with 3 mg/kg/day of amphotericin B colloidal dispersion for at least 28 days. Although all of the patients initially responded by clinical observation, all four patients relapsed within six months. The use of amphotericin B colloidal dispersion for the initial induction of paracoccidioidomycosis failed to cure this infection. Possible reasons for failure include dose, duration, or reduced efficacy of this lipid preparation. For many fungal infections, lipid-based preparations have been shown to have a therapeutic-toxic advantage, but our experience with Paracoccidioides infections suggests that more careful studies will need to be performed before they can be recommended for use in this mycosis.

Adult↗
PubMed1999

Imported African tick bite fever: a case report.

We describe a patient with African tick-bite fever who acquired his infection while visiting rural areas of South Africa and then became sick after returning to the United States. The dominant clinical feature of his illness was the presence of multiple, ulcerated lesions (tache noires). Physicians in the United States and other non-African countries who see travelers returning from southern parts of Africa who give a history of recent tick bite and/or present with multiple, crusted or vesicular skin lesions should be alert to this diagnosis and institute treatment with doxycycline.

Aged↗
PubMed1998

Incidence and outcome of Staphylococcus aureus bacteremia in hemodialysis patients.

BACKGROUND: Staphylococcus aureus bacteremia is frequently associated with metastatic complications and infective endocarditis (IE). The Duke criteria for the diagnosis of IE utilize echocardiographic techniques and are more sensitive than previous criteria. The documentation of IE in patients undergoing hemodialysis (HD) has become increasingly important in order to avoid the overuse of empiric vancomycin and the emergence of antibiotic resistance. METHODS: Patients who developed S. aureus bacteremia while undergoing HD at a tertiary medical center or one of four affiliated outpatient HD units were identified. Clinical outcome (death, metastatic complications, IE, and microbiologic recurrence) was assessed during hospitalization and at three months after discharge. Transthoracic and transesophageal echocardiograms were performed and the Duke criteria were used to diagnose IE. Pulse field gel electrophoresis was performed to confirm genetic similarity of recurrent isolates. RESULTS: Four hundred and forty-five patients underwent hemodialysis for 5431.8 patient-months. Sixty-two developed 65 episodes of S. aureus bacteremia (1.2 episodes/100 patient-months). Complications occurred in 27 (44%) patients. Bacteremia recurred in patients who dialyzed through polytetrafluorethylene grafts (44.4% vs. 7.1%, P = 0.0.01), and there was a trend to increased recurrence in patients who received only vancomycin (19.5% vs. 7.1%, P = 0.4). IE was diagnosed in 8 patients (12%), six of whom had normal transthoracic echocardiograms. CONCLUSIONS: Sensitive echocardiographic techniques and the Duke criteria for the diagnosis of IE should be used to determine the proper duration of antibiotic therapy in hemodialysis patients with S. aureus bacteremia. This diagnostic approach, coupled with early removal of hardware, may assist in improving outcomes.

Adult↗
PubMed1998

Outcome of Staphylococcus aureus bacteremia according to compliance with recommendations of infectious diseases specialists: experience with 244 patients.

To determine whether recommendations of infectious diseases specialists affect outcome for patients, we evaluated 244 hospitalized patients with Staphylococcus aureus bacteremia. We offered our management recommendations to each patient's physicians and then assessed the clinical outcome for both patients for whom our consultative advice was followed and those for whom our advice was not heeded. All patients were followed up for 12 weeks after their first positive blood culture. Our management advice was followed for 112 patients (45.9%) and partially or completely ignored for 132 patients (54.1%). Patients for whom our recommendations were followed were more likely to be cured of their S. aureus infection and less likely to relapse (P < .01), despite having significantly more metastatic infections (P < .01) at the outset of therapy, than were those for whom our recommendations were not followed. Failure to follow recommendations to remove an infected intravascular device was the most important risk for treatment failure. After controlling for other factors, logistic regression analysis revealed that patients whose intravascular device was not removed were 6.5 times more likely to relapse or die of their infection than were those whose device was removed. Our findings suggest that patient-specific management advice by infectious diseases consultants can improve the clinical outcome for patients with S. aureus bacteremia.

Algorithms↗
PubMed1998

Native valve infective endocarditis in elderly and younger adult patients: comparison of clinical features and outcomes with use of the Duke criteria and the Duke Endocarditis Database.

The effect of age on the presentation and outcome of infective endocarditis (IE) is unclear. Many of the available data are based on analyses of mixed populations of patients including intravenous drug users or those with prosthetic valve endocarditis or native valve IE. We used the Duke criteria to compare the characteristics of 44 episodes of definite native valve IE in elderly patients (> 64 years old) with the characteristics of 64 similarly defined episodes of native valve IE in younger, nonintravenous-drug-using adult patients (> 29 years and < 60 years old). Our data suggest that the clinical presentation, characteristics, and outcome of native valve IE are similar for elderly patients and younger adult patients, although elderly patients were hospitalized an average of 12 days longer. Although we found that the occurrence of renal failure and cerebral embolism during an episode of IE was associated with higher rates of death (odds ratios, 4.8 and 4.0, respectively), age was not a significant contributor to mortality.

Adult↗
PubMed1998

In vitro resistance to thrombin-induced platelet microbicidal protein among clinical bacteremic isolates of Staphylococcus aureus correlates with an endovascular infectious source.

Platelet microbicidal proteins (PMPs), small cationic peptides released at sites of endovascular damage, kill common bloodstream pathogens in vitro. Our group previously showed that in vitro resistance of clinical staphylococcal and viridans group streptococcal bacteremic strains to PMPs correlated with the diagnosis of infective endocarditis (IE) (Wu et al., Antimicrob. Agents Chemother. 38:729-732, 1994). However, that study was limited by (i) the small number of Staphylococcus aureus isolates from IE patients, (ii) the retrospective nature of the case definitions, and (iii) the diverse geographic sources of strains. The present study evaluated the in vitro PMP susceptibility phenotype of a large number of staphylococcemic isolates (n = 60), collected at a single medical center and categorized by defined and validated clinical criteria. A significantly higher proportion of staphylococcemic strains from patients with IE was PMP resistant in vitro than the proportion of strains from patients with soft tissue sepsis (83% and 33%, respectively; P < 0.01). Moreover, the levels of PMP resistance (mean percent survival of strains after 2-h exposure to PMP in vitro) were significantly higher for isolates from patients with IE and with vascular catheter sepsis than for strains from patients with abscess sepsis (P < 0.005 and P < 0.01, respectively). These data further support the concept that bloodstream pathogens that exhibit innate or acquired PMP resistance have a survival advantage with respect to either the induction or progression of endovascular infections.

Anti-Bacterial Agents↗
PubMed1998

Predictors of prognosis and risk of acute renal failure in bacterial endocarditis.

BACKGROUND: The epidemiology, criteria for diagnosis and treatment of bacterial endocarditis has changed substantially in the past 2 decades, yet little attention has been given to the changing etiologies of renal insufficiency and the predictors of renal failure or the relationship between renal failure and mortality in patients with bacterial endocarditis. OBJECTIVE: To study the risk factors for the development of acute renal failure and death among patients with definite bacterial endocarditis. SETTING: Tertiary referral university medical center. METHODS: Retrospective chart review of 204 consecutive episodes of definite bacterial endocarditis as defined by the Duke criteria. Logistic regression was used to identify clinical and biochemical predictors of death and the development of acute renal failure. RESULTS: Two hundred and four episodes of endocarditis identified in 185 patients were evaluated. The overall mortality for the group was 20%. The presence of prosthetic valve endocarditis and thrombocytopenia was associated with increased risk of death in hospital. One third of the patients developed acute renal failure (defined as a serum Cr of 2 mg/dl or above). The presence of acute renal failure increased the odds (OR) of dying by 5 (p = 0.0001). Clinical and biochemical variables at presentation that were significantly associated by univariate analysis with the risk of developing acute renal failure were: increased age, a history of hypertension, thrombocytopenia, the presence of Staphylococcus aureus, and prosthetic valve infection. Age (OR 2.9, p = 0.002) and the degree of thrombocytopenia (OR 0.2, p = 0.0001) were independently associated with an increased risk of developing acute renal failure. Patients who developed acute renal failure as a result of septic syndrome or following cardiac surgery had a higher mortality when compared to other causes of acute renal failure. CONCLUSION: Acute renal failure associated with bacterial endocarditis remains a frequent clinical problem that is often associated with a fatal outcome. Patients with increased age, and the degree of thrombocytopenia were independent risk factors for developing acute renal failure.

Acute Kidney Injury↗
PubMed1997

Catheter-related bacteremia and outcome of attempted catheter salvage in patients undergoing hemodialysis.

BACKGROUND: Dual-lumen cuffed catheters are used for vascular access in patients undergoing hemodialysis. The incidence and appropriate management of catheter-related bacteremia are unknown. OBJECTIVE: To determine the incidence and outcome of catheter-related bacteremia and to assess the efficacy of catheter salvage. DESIGN: Prospective, observational study. SETTING: University hospital inpatient service and four affiliated outpatient dialysis units. PATIENTS: 102 patients with end-stage renal disease who underwent hemodialysis with dual-lumen cuffed catheters between 1 April 1995 and 1 January 1996. MEASUREMENTS: Number of days that the catheter remained in situ, treatment (catheter removal or attempted salvage with antibiotic therapy), and outcome of bacteremia. Microbiological cultures were done to identify catheter-related bacteremia. RESULTS: 102 patients had a total of 16,081 catheter-days. Forty-one patients (40%) developed 62 episodes of bacteremia (3.9 episodes per 1000 catheter-days [95% CI, 3.0 to 4.9 episodes per 1000 catheter-days]). Twenty-four catheters (39%) were removed immediately, and 38 (61%) were left in place during treatment. Only 12 (32%) of the 38 catheters were salvaged successfully. Salvage was less likely to succeed in patients with gram-positive bacteremia than in patients with gram-negative bacteremia, but this difference was not statistically significant (P = 0.14). Nine of the 41 patients (22%) who developed bacteremia had the following complications: osteomyelitis (6 patients), septic arthritis (1 patient), infective endocarditis (4 patients), and death (2 patients). All complications followed an episode of gram-positive bacteremia, and none was associated with attempted catheter salvage. CONCLUSIONS: Bacteremia frequently occurs in patients undergoing hemodialysis with dual-lumen catheters. Antibiotic therapy without catheter removal is unlikely to eradicate catheter-related bacteremia in these patients, but attempted salvage may not increase the risk for complications.

Adult↗
PubMed1997

Role of echocardiography in evaluation of patients with Staphylococcus aureus bacteremia: experience in 103 patients.

OBJECTIVES: The purpose of this prospective study was to examine the role of echocardiography in patients with Staphylococcus aureus bacteremia (SAB). BACKGROUND: The reported incidence of infective endocarditis (IE) among patients with SAB varies widely. Distinguishing patients with uncomplicated bacteremia from those with IE is therapeutically and prognostically important, but often difficult. METHODS: One hundred-three consecutive patients undergoing both transthoracic (TTE) echocardiography and transesophageal (TEE) echocardiography were prospectively evaluated. All patients presented with fever and > or = 1 positive blood culture and were followed up for 12 weeks. RESULTS: Although predisposing heart disease was present in 42 patients (41%), clinical evidence of infective endocarditis (IE) was rare (7%). TTE revealed anatomic abnormalities in 33 patients, but vegetations in only 7 (7%), and was considered indeterminate in 19 (18%). TEE identified vegetations in 22 patients (aortic valve in 5, mitral valve in 9, tricuspid valve in 4, catheter in 2 and pacemaker in 2, abscesses in 2, valve perforation in 1 and new severe regurgitation in 1; 26 total [25%]). Using Duke criteria for the diagnosis of IE, definite IE was present in 26 patients (25%). Clinical findings and predisposing heart disease did not distinguish between patients with and without IE. The sensitivity of TTE for detecting IE was 32%, and the specificity was 100%. The addition of TEE increased the sensitivity to 100%, but resulted in one false positive result (specificity 99%). TEE detected evidence of IE in 19% of patients with a negative TTE and 21% of patients with an indeterminate TTE. At follow-up, cure of staphylococcal infection occurred in a similar percentage of patients with and without IE (77% and 75%, respectively). However, death due to sepsis was significantly more likely among patients with IE (4 of 26 [15%]) than among those without IE (2 of 77 [3%]) (p = 0.03). CONCLUSIONS: Our results suggest that IE is common among patients admitted to the hospital with SAB and is associated with an increased risk of death due to sepsis. TEE is essential to establish the diagnosis and to detect associated complications. Therefore, the test should be considered part of the early evaluation of patients with SAB.

Aged↗