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Biomedical subjects

Patricia Muñoz

Publications and source records attributed to Patricia Muñoz.

At least 19 recordsLinked to original sources

Direct E-test (AB Biodisk) of respiratory samples improves antimicrobial use in ventilator-associated pneumonia.

BACKGROUND: Ventilator-associated pneumonia is the most frequently observed nosocomial infection in intensive care units, and it is associated with high morbidity and mortality. Early microbiological diagnosis and the initial administration of appropriate antimicrobial therapy are associated with decreased mortality and potentially reduced costs. Our study evaluates the clinical and financial impact of performing rapid antimicrobial susceptibility tests directly on samples obtained from the lower respiratory tract. METHODS: A prospective, randomized study was performed over a 2-year period. Patients who had a lower respiratory tract infection that was acquired during mechanical ventilation and for whom samples obtained from the respiratory tract were sent for culture were randomized to 1 of 2 groups. Samples were cultured for the control group, and results were reported using standard procedures. Samples were also cultured for the test subject group using standard procedures, but in addition, a rapid antibiogram was immediately performed by placing E-test antibiotic strips (AB Biodisk) directly on respiratory tract samples. Patients in the E-test group received a preliminary laboratory report when it became available. The 2 patient groups were compared according to the following variables: type and severity of underlying conditions, total days of antimicrobial use, number of defined daily doses, cost of acquisition of the antimicrobial agent per episode, days of fever, days receiving mechanical ventilation, days in the intensive care unit, incidence of Clostridium difficile-associated diarrhea, and mortality. RESULTS: Reporting a rapid E-test was associated with fewer days of fever, fewer days of antibiotic administration until resolution of the episode of ventilator-associated pneumonia, decreased antibiotic consumption, less C. difficile-associated diarrhea, lower costs of antimicrobial agents, and fewer days receiving mechanical ventilation. CONCLUSIONS: A rapid E-test of respiratory tract samples improves antimicrobial use in cases of ventilator-associated pneumonia.

Aged↗

Periannular complications in infective endocarditis involving prosthetic aortic valves.

The periannular extension of infection in prosthetic valve endocarditis (PVE) is a serious complication of infective endocarditis associated with high mortality. Periannular lesions in PVE occasionally rupture into adjacent cardiac chambers, leading to aortocavitary fistulae and intracardiac shunting. It is unknown whether the prognosis of patients with aortocavitary fistulae is worse than that of those with nonruptured abscesses. The aims of this study were to determine the distinctive clinical characteristics of patients with PVE and either aortocavitary fistulization or nonruptured abscesses. In a retrospective multicenter study of >872 PVE episodes, 150 patients (17%) with periannular complications in PVE in the aortic position were identified (29 with aortocavitary fistulization and 121 with nonruptured abscesses). Early-onset PVE was present in 73 patients (49%). Rates of heart failure (p = 0.09), ventricular septal defect (p <0.01), and third-degree atrioventricular block (p = 0.07) were higher in patients with fistulization. Surgical treatment was undertaken in 128 patients (83%). In-hospital mortality in the overall population was 39%. Multivariate analysis identified heart failure (odds ratio [OR] 3.3, 95% confidence interval [CI] 1.6 to 6.8), renal failure (OR 2.5, 95% CI 1.2 to 5.2), and co-morbidity (OR 2.4, 95% CI 1.1 to 5.1) as independent risk factors for death. Fistulous tract formation was not associated with increased in-hospital mortality (OR 1.6, 95% CI 0.7 to 3.7). The actuarial 5-year survival rate in surgical survivors was 100% in patients with fistulae and 78% in patients with nonruptured abscesses (log-rank p = 0.14). In conclusion, aortocavitary fistulous tract formation in PVE complicated with periannular complications is associated with higher rates of heart failure, ventricular septal defect, and atrioventricular block than nonruptured abscesses. Despite the frequent complications, fistulous tract formation in the current era of infective endocarditis is not an independent risk factor for mortality.

Abscess↗

Periannular complications in infective endocarditis involving native aortic valves.

The extension of infection in native valve infective endocarditis (IE) from valvular structures to the periannular tissue is incompletely understood. It is unknown, for example, whether the prognosis of patients with aortocavitary fistulae is worse than that of those with nonruptured abscesses. The aims of this study were to determine the distinct clinical characteristics of patients with aortocavitary fistulae and nonruptured abscesses in native valve IE and to evaluate the impact of fistulization on the outcomes of patients with native aortic valve IE complicated with periannular lesions. In a retrospective multicenter study of 2,055 native valve IE episodes, 201 patients (9.8%) with periannular complications in aortic valve IE were identified (46 with aortocavitary fistulization and 155 with nonruptured abscesses). Rates of heart failure (p = 0.07), ventricular septal defect (p <0.001), and third-degree atrioventricular block (p = 0.07) were higher in patients with fistulization. Surgical treatment was undertaken in 172 patients (86%), and in-hospital mortality in the overall population was 29%. Multivariate analysis identified age >60 years (odds ratio [OR] 2.6, 95% confidence interval [CI] 1.3 to 5.2), renal failure (OR 3.0, 95% CI 1.5 to 6.0), and moderate or severe heart failure (OR 2.5, 95% CI 1.2 to 5.2) as independent risk factors for death. There was a trend toward increased in-hospital mortality in patients with aortocavitary fistulae (OR 1.5, 95% CI 0.7 to 3.0). The actuarial 5-year survival rate in surgical survivors was 80% in patients with fistulae and 92% in patients with nonruptured abscesses (log-rank p = 0.6). In conclusion, aortocavitary fistulous tract formation in the setting of native valve IE is associated with higher rates of heart failure, ventricular septal defect, and atrioventricular block than nonruptured abscess. Despite these higher rates of complications, fistulous tract formation in the current era of IE is not an independent risk factor for mortality.

Abscess↗

Cultures of sternal wound and mediastinum taken at the end of heart surgery do not predict postsurgical mediastinitis.

The aim of the study was to assess of the role of intraoperative cultures taken at the end of major heart surgery (MHS) in the prediction of postoperative mediastinitis (PM) in patients undergoing MHS over a 6-month period in a tertiary university hospital. Just before wound closure, a sample of the sternal border was taken, swabbing back and forth the sternal border and the subcutaneous tissues. A second sample was taken after irrigation of the deep mediastinal structures with 10 mL of Ringer lactate. Swabs were processed semiquantitatively and the mediastinal fluid with a quantitative technique. The observation of one or more colonies per plate was considered a positive culture. Cultures obtained at the end of 229 surgical interventions (227 patients) were positive with the semiquantitative or with the quantitative procedures in 31.0% (95% confidence interval [CI], 25.1-37.4%) and 34.5% (95% CI, 28.4-41.0%) of the times, respectively (P = NS). The number of microorganisms isolated in the wound swab or mediastinal fluid was 91 and 110, respectively. Of the 227 patients, 7 developed an episode of PM (3.1%; 95% CI, 1.2-6.2%) after a median time of 11 days (range, 5-19 days). The microorganisms causing the 7 cases of mediastinitis were not isolated in the intraoperative cultures in any of the cases. The value of intraoperative cultures as a test for prediction of PM depending on the breakpoint chosen were as follows: sensitivity (0%), specificity (66.2-97.3%), and positive (0%) and negative predictive values (96.8-98.0%). We recommend against surveillance cultures taken intraoperatively in patients undergoing MHS.

Cardiac Surgical Procedures↗

An instant procedure to demonstrate catheter-tip colonization may help clinicians.

This study compared the acridine orange and Gram stains of an external smear of intravascular catheter-tip segments with the culture results obtained 24 to 48 h later. Both staining techniques were randomly assigned to be performed either before (group A) or after (group B) rolling on the agar plate. Of the 425 catheter tips processed, 25.7% were significantly colonized and 6.1% were from patients with catheter-related bloodstream infections (CRBSIs). The yield of group A was superior to that of group B for the prediction of colonization (sensitivity, 94.3%/69.6%; specificity, 92.4%/96.2%; positive predictive value (PPV), 80.6%/86.7%; negative predictive value (NPV), 98.0%/90.0%; and full concordance, 91.9%/89.3%). The values for the prediction of CRBSIs were as follows for group A and group B: sensitivity, 100%/69.2%; specificity, 96.3%/100%; PPV, 86.7%/100.0%; NPV, 100%/93.9%; and full concordance, 97.0%/94.7%. Catheter-tip staining before culture is an easy-to-perform, cheap, and effective procedure to anticipate catheter colonization and rule out CRBSIs.

Acridine Orange↗

Bloodstream infections among heart transplant recipients.

BACKGROUND: Heart transplant (HT) recipients are prone to life-threatening infections, including bloodstream infection (BSI), but information on this topic is particularly scarce. METHODS: We studied 309 consecutive HT performed at our institution between 1988 and 2003. We assessed the characteristics of each episode of BSI, prophylaxis and immunosuppression used, and possible related factors. RESULTS: Sixty episodes of BSI occurred in 15.8% of all HT recipients. Rates of BSI/transplanted patient decreased progressively throughout the study period: 21.2%, 14.3%, and 7.5% in each 5-year period (P=0.03). BSI episodes occurred a median of 51 days after transplantation. The main BSI origins were: lower respiratory tract (23%), urinary tract (20%), and catheter-related-BSI (16%). Gram-negative organisms predominated (55.3%), followed by Gram-positive (44.6%). Mortality was 59.2%, with 12.2% directly attributable to BSI. Independent risk factors for BSI after HT were: hemodialysis (OR 6.5; 95% CI 3.2-13), prolonged intensive care unit stay (OR 3.6; 95% CI 1.6-8.1), and viral infection (OR 2.1; 95% CI 1.1-4). BSI was a risk factor for mortality (OR 1.8; 95% CI 1.2-2.8). CONCLUSION: BSIs have decreased in HT recipients, but still contribute to mortality, mainly if related to pneumonia or polymicrobial infections. Reduction of early postoperative complications and viral infections are amenable goals that may further reduce BSI in this population.

Bacteremia↗

Combination of voriconazole and caspofungin as primary therapy for invasive aspergillosis in solid organ transplant recipients: a prospective, multicenter, observational study.

BACKGROUND: : The efficacy of the combination of voriconazole and caspofungin when used as primary therapy for invasive aspergillosis in organ transplant recipients has not been defined. METHODS: : Transplant recipients who received voriconazole and caspofungin (n=40) as primary therapy for invasive aspergillosis (proven or probable) in a prospective multicenter study between 2003 and 2005 were compared to a control group comprising a cohort of consecutive transplant recipients between 1999 and 2002 who had received a lipid formulation of AmB as primary therapy (n=47). In vitro antifungal testing of Aspergillus isolates to combination therapy was correlated with clinical outcome. RESULTS: : Survival at 90 days was 67.5% (27/40) in the cases, and 51% (24/47) in the control group (HR 0.58, 95% CI, 0.30-1.14, P=0.117). However, in transplant recipients with renal failure (adjusted HR 0.32, 95% CI: 0.12-0.85, P=0.022), and in those with A. fumigatus infection (adjusted HR 0.37, 95% CI: 0.16-0.84, P=0.019), combination therapy was independently associated with an improved 90-day survival in multivariate analysis. No correlation was found between in vitro antifungal interactions of the Aspergillus isolates to the combination of voriconazole and caspofungin and clinical outcome. CONCLUSIONS: : Combination of voriconazole and caspofungin might be considered preferable therapy for subsets of organ transplant recipients with invasive aspergillosis, such as those with renal failure or A. fumigatus infection.

Adult↗

Invasive aspergillosis in the recipients of liver retransplantation.

Retransplantation is a major risk factor for invasive aspergillosis in liver transplant recipients. However, the risk for invasive aspergillosis with time elapsed since retransplantation, clinical characteristics, and outcome of patients who develop this infection after retransplantation of the liver has not been defined. Patients comprised 17 liver retransplant recipients with invasive aspergillosis between 1990 and 2004. Retransplantation was considered early if it was performed within 30 days and late if performed after 30 days of the first or primary transplant. Retransplant recipients comprised 25% of all cases of invasive aspergillosis after liver transplantation. Fifty-three percent of the Aspergillus infections occurred within 30 days, and 76% within 90 days of retransplantation. In all, 53% (9/17) of the patients were late retransplant recipients. Late compared to early retransplant recipients with invasive aspergillosis were more likely to have central nervous system involvement with invasive aspergillosis (56% vs. 0%, P = 0.03). Mortality rate was 100% for late and 63% for early retransplant recipients with Aspergillus infections. In conclusion, time-varying risk for invasive aspergillosis after retransplantation has implications relevant for guiding antifungal prophylaxis. Given a greater risk for disseminated infection and poor outcome in late retransplant recipients with aspergillosis, potent and aggressive antifungal therapy should be considered upfront in these patients.

Adolescent↗

Antimicrobial therapy of Clostridium difficile-associated diarrhea.

Clostridium difficile-associated diarrhea (CDAD) is the most common etiologically-defined cause of hospital-acquired diarrhea. Caused by the toxins of certain strains of C difficile, CDAD represents a growing concern, with epidemic outbreaks in some hospitals where very aggressive and difficult-to-treat strains have recently been found. Incidence of CDAD varies ordinarily between 1 to 10 in every 1,000 admissions. Evidence shows that CDAD increases morbidity, length of stay, and costs. This article described the clinical manifestations of CDAD, related risk factors, considerations for confirming CDAD, antimicrobial and non-antimicrobial treatment of CDAD, and issues related to relapses. The article concludes with a discussion of recent epidemic outbreaks involving CDAD.

Aged↗

Late-onset invasive aspergillosis in organ transplant recipients in the current era.

We assessed predictive factors and characteristics of patients with late-onset invasive aspergillosis in the current era of novel immunosuppressive agents. Forty transplant recipients with invasive aspergillosis were included in this prospective, observational study initiated in 2003 at our institutions. In 50% (20/40) of these patients, the infections were late-occurring. Receipt of sirolimus in conjunction with tacrolimus for refractory rejection or cardiac allograft vasculopathy (P=0.047) was significantly associated with late-onset infection. The use of depleting or non-depleting T or B-cell antibodies, either as induction or as antirejection therapy did not correlate with time to onset of invasive aspergillosis. Mortality at 90 days was 20% (4/20) for the patients with early-onset infection and 45% (9/20) for those with late-onset infection (P=0.17). Thus, nearly one-half of the Aspergillus infections in transplant recipients in the current era are late-occurring. These data have implications relevant for prophylactic strategies and guiding clinical management of transplant recipients presenting with pulmonary infiltrates.

Adult↗

Treatment of solid organ transplant patients with invasive fungal infections: should a combination of antifungal drugs be used?

PURPOSE OF REVIEW: Combined antifungal drug therapy is widely used in severe invasive mycoses in solid organ transplant (SOT) recipients. We have reviewed the available data in the literature. RECENT FINDINGS: No single randomized study on antifungal combination therapy in SOT patients has been performed. Existing information does not support the use of combination therapy in invasive candidiasis in SOT patients. Indeed, initial combination therapy with amphotericin B and 5-flucytosine is recommended for SOT patients with central nervous system cryptococcosis, mainly with increased white blood cell counts in the cerebrospinal fluid or with altered mental status. No impact on outcome was observed with combination therapy in Scedosporium infections in SOT patients. The combination of voriconazole and terbinafine may be an attractive option for S. prolificans infections. A prospective study of voriconazole plus caspofungin as initial therapy for invasive aspergillosis in SOT patients found that combination therapy was independently associated with reduced mortality in patients with renal failure and in those with Aspergillus fumigatus infection, even when adjusted for other factors predictive of mortality in the study population. SUMMARY: Combination therapy should be considered for severe forms of invasive fungal infections in SOT patients; however, multicenter studies of such patients are urgently needed.

Antifungal Agents↗

Prevalence of BK virus replication among recipients of solid organ transplants.

BACKGROUND: BK virus (BKV) has been implicated as a cause of nephritis and graft loss in 2%-9% of kidney transplant recipients, but the prevalence among recipients of other solid organ transplants (SOTs) has not been well established. Our objective was to determine the prevalence of BKV infection for all types of SOT recipients at our medical center. METHODS: A total of 156 consecutive SOT recipients were studied, of whom 49 received kidney transplants, 43 received heart transplants, and 64 received liver transplants. Samples were obtained a median of 559 days (range, 1-9481 days) after transplantation. Nested polymerase chain reaction was performed for detection of BKV DNA in urine and plasma specimens. RESULTS: BKV was found in 19% of urine specimens and 6% of plasma specimens. The prevalence of viruria after kidney, heart, and liver transplantation was 26.5%, 25.5%, and 7.8%, respectively. BKV viremia was detected in 12.2% of kidney transplant recipients and 7% of heart transplant recipients. Mean creatinine levels were higher in patients with BKV viruria or viremia (1.9 and 3.5 mg/dL, respectively) than in patients with no BKV replication (1.3 mg/dL). Independent factors related to impaired renal function were renal transplantation (odds ratio [OR], 14.4); BKV replication, including viruria or viremia (OR, 3.3); and mycophenolate use (OR, 2.6). CONCLUSION: BKV is common in all types of SOT recipients, particularly those who have received heart or kidney transplants.

BK Virus↗

Antifungal management practices and evolution of infection in organ transplant recipients with cryptococcus neoformans infection.

BACKGROUND: Therapeutic practices for Cryptococcus neoformans infection in transplant recipients vary, particularly with regards to antifungal agent employed, and duration of therapy. The risk of relapse and time to recurrence is not known. We assessed antifungal treatment practices for cryptococcosis in a cohort of prospectively followed organ transplant recipients. METHODS: The patients comprised 83 transplant recipients with cryptococcosis followed for a median of 2.1 and up to 5.2 years. RESULTS: Patients with central nervous system infection (69% vs. 16%, P = 0.00001), disseminated infection (82.7% vs. 20%, P = 0.00001), and fungemia (29% vs. 8%, P = 0.046) were more likely to receive regimens containing amphotericin B than fluconazole as primary therapy. The use of fluconazole, on the other hand, was more likely for infection limited to the lungs (64% vs. 14%, P = 0.00002). Survival at 6 months tended to be lower in patients whose CSF cultures at 2 weeks were positive compared to those whose CSF cultures were negative (50% vs. 91%, P = 0.06). Maintenance therapy was employed in 68% (54/79) of the patients who survived >3 weeks. The median duration of maintenance therapy was 183 days; 55% received maintenance for > or = 6 months and 25% for >1 year. Relapse was documented in 1.3% (1/79) of the patients. CONCLUSIONS: A majority of the organ transplant recipients with cryptococcosis receive maintenance antifungal therapy for 6 months with low risk of relapse. These data can assist in trials to assess the optimal therapeutic approach and duration of therapy for cryptococcosis in transplant recipients.

Adult↗

Saccharomyces cerevisiae fungemia: an emerging infectious disease.

BACKGROUND: Saccharomyces cerevisiae is well known in the baking and brewing industry and is also used as a probiotic in humans. However, it is a very uncommon cause of infection in humans. METHODS: During the period of 15-30 April 2003, we found 3 patients with S. cerevisiae fungemia in an intensive care unit (ICU). An epidemiological study was performed, and the medical records for all patients who were in the unit during the second half of April were assessed. RESULTS: The only identified risk factor for S. cerevisiae infection was treatment with a probiotic containing Saccharomyces boulardii (Ultralevura; Bristol-Myers Squibb). This probiotic is used in Europe for the treatment and prevention of Clostridium difficile-associated diarrhea. The 3 patients received the product via nasograstric tube for a mean duration of 8.5 days before the culture result was positive, whereas only 2 of 41 control subjects had received it. Surveillance cultures for the control patients admitted at the same time did not reveal any carriers of the yeast. Strains from the probiotic capsules and the clinical isolates were identified as S. cerevisiae, with identical DNA fingerprinting. Discontinuation of use of the product in the unit stopped the outbreak of infection. A review of the literature identified another 57 cases of S. cerevisiae fungemia. Overall, 60% of these patients were in the ICU, and 71% were receiving enteral or parenteral nutrition. Use of probiotics was detected in 26 patients, and 17 patients died. CONCLUSIONS: Use of S. cerevisiae probiotics should be carefully reassessed, particularly in immunosuppressed or critically ill patients.

Aged↗

A prospective, randomized, and comparative study of 3 different methods for the diagnosis of intravascular catheter colonization.

BACKGROUND: Demonstration of catheter tip colonization is usually performed by use of Maki's semiquantitative technique, although the superiority of quantitative techniques has been claimed on the basis of their purported ability to detect both endoluminal and exoluminal microorganisms. METHODS: We prospectively compared Maki's semiquantitative technique and the quantitative methods of sonication and vortexing for the detection of colonization of intravascular catheter tips and catheter-related bloodstream infections. All 3 techniques were performed on the tip of each catheter, and the order in which each technique was performed was randomly assigned. RESULTS: Of the 1000 catheter tips that were processed, 329 (32.9%) had positive results for at least 1 of the 3 techniques when a breakpoint of >or=100 colony-forming units (cfu)/catheter segment was used for the quantitative techniques and a breakpoint of >or=15 cfu was used for Maki's technique. Eighty-two of the catheter tips for which results were positive were from patients with catheter-related bloodstream infections. For each technique, the likelihood of detection decreased progressively depending on the order in which the technique was performed (i.e., second vs. first and third vs. second). The likelihood of detection of catheter colonization for each technique, when the technique was performed first and when 2 breakpoints (>or=100 cfu/catheter segment [criterion B] and >or=1000 cfu/catheter segment [criterion A]) were used for the quantitative techniques and a breakpoint of >or=15 cfu was used for Maki's technique, was as follows: 99.1% and 100% for Maki's technique, 95.1% and 92.9% for sonication, and 93.1% and 72.8% for vortexing (for criteria B and A, respectively). No inferiority of Maki's technique could be demonstrated when results were compared according to whether catheter placement was short term (i.e., <7 days) or long term (i.e., >or=7 days), either for the detection of colonization or for the detection of catheter-related bloodstream infections. CONCLUSIONS: According to data from the present study, the quantitative techniques of sonication and vortexing were not superior to Maki's technique under the test conditions used. The greater simplicity of Maki's semiquantitative technique makes it the procedure of choice for routine work in the microbiology laboratory.

Bacterial Infections↗