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Biomedical subjects

C M Luna

Publications and source records attributed to C M Luna.

17 recordsLinked to original sources
PubMed2006

Appropriateness and delay to initiate therapy in ventilator-associated pneumonia.

Inappropriate therapy (IT) and delayed initiation of appropriate therapy (DIAT) result in inadequate therapy in patients with ventilator-associated pneumonia (VAP). The aim of the current study was to assess the impact of DIAT in VAP. A total of 76 mechanically ventilated patients with bacteriologically confirmed VAP were prospectively evaluated in the intensive care unit of six hospitals in Buenos Aires, Argentina. Appropriate therapy was defined as coverage of all the identified pathogens by the antimicrobial therapy administered at the time of VAP clinical diagnosis. The clinical pulmonary infection score was measured during the 3 days before, at the onset and during the days which followed the onset of VAP. A total of 24 patients received adequate therapy; mortality was 29.2%. The remaining 52 patients received either IT (n = 16) or DIAT (n = 36); the mortality was 63.5% combined, and 75.0 and 58.3% for IT and DIAT, respectively (statistically significant compared with adequate therapy). Inappropriate therapy and delayed initiation of appropriate therapy increased the mortality of ventilator-associated pneumonia. Patients with inappropriate therapy and/or delayed initiation of appropriate therapy had a more gradual increase in clinical pulmonary infection score than those receiving adequate therapy, and this increase was found to occur prior to the time of the clinical diagnosis. In conclusion, these findings might provide the rationale for a trial of earlier initiation of therapy, based on clinical grounds in an effort to improve the outcome of patients with ventilator-associated pneumonia.

Aged↗
PubMed2001

Effects of supplemental oxygen during activity in patients with advanced COPD without severe resting hypoxemia.

STUDY OBJECTIVES: To assess oxygen desaturation during activities and to evaluate the short-term effects of supplemental O(2) use in patients with severe COPD who do not qualify for long-term O(2) therapy. DESIGN: A double-blind, randomized, placebo-controlled trial. SETTING: Outpatients from the pulmonary diseases division of a tertiary-care university hospital. PATIENTS: Twenty patients with stable COPD with FEV(1)/FVC ratios of < 50%, FEV(1) levels < 55% of the predicted normal value, and PaO(2) levels of > 60 mm Hg when resting. INTERVENTIONS: Patients were initially evaluated with pulmonary function tests, blood gas analysis, and Doppler echocardiography, and they underwent the following three 6-min walking tests (WTs) in a random sequence: basal WT (BWT); WT while breathing compressed air (CAWT); and WT while breathing O(2) (O(2)WT). MEASUREMENTS AND RESULTS: The distance walked was recorded in meters. Dyspnea was measured by Borg scale measurement before and after the tests, and arterial oxygen saturation measured by pulse oximetry (SpO(2)) was continuously monitored. Results were analyzed by grouping patients in the following manner: desaturators (DSs) (ie, patients with a drop in SpO(2) of at least 5% and < 90% during the WT) vs nondesaturators (NDSs); and O(2) responders (ie, patients with an increase of at least 10% in the distance walked and/or a decrease of at least 3 points in Borg index score) vs nonresponders. During the BWT, 11 of 20 patients (55%) were defined as desaturators. During the O(2)WT, the SpO(2) remained at > 90% in every patient. The distance walked increased by 22% (p < 0.02), and dyspnea decreased 36% (p < 0.01) in DS patients. In NDS patients, O(2) administration reduced dyspnea by 47% (p < 0.001), but the distance walked did not improve. Responses were markedly different from one patient to another. No significant differences were noticed between the results of the BWT and CAWT in any of the groups. Thirteen O(2) responders did not differ from 7 nonresponders either in basal data or in desaturation measure during the BWT, except that all walking responders (five patients) were above the median of basal left ventricle performance. CONCLUSIONS: Most of the studied COPD patients desaturated during the BWT. O(2) administration avoided desaturation and could increase the distance walked and reduce dyspnea, but these effects were not related to walking desaturation in individual cases. Improvements were not a placebo effect. The therapeutic role of O(2) during activities in some patients with severe COPD needs to be individually assessed.

Aged↗
PubMed2001

[Bacterial resistance and antimicrobial therapy in respiratory medicine and intensive care].

Nosocomial pneumonia is the leading cause of mortality among the infections produced by multi-resistant microorganisms in intensive care units (ICU). The solution of this problem created by the colonization and infection of the respiratory tract is beyond respiratory medicine and requires a multi-disciplinary approach, involving other nosocomial infections in the ICU. Up to 80% ICU patients receive antibiotics for severe infections or prophylactically, frequently with no clear justification for these treatments. The extended use of antibiotics increases the problem by exerting a selective pressure favoring the development of resistant organisms. Some evidences suggest that the infections produced by multi-resistant pathogens increase the mortality of nosocomial pneumonia. The following mechanisms are responsible for the acquisition of resistance: alteration of bacterial wall permeability; production of inactivating enzymes, modification of the target site, or eflux. Resistance is genetically transmitted by chromosomes or by plasmids. At the present time staphylococci (Staphylococcus aureus and coagulase-negative staphylococci) and enterococci predominate among the gram-positives, and non-fermenters (Pseudomonas aeruginosa, Acinetobacter spp) and some Enterobacteriaceae among the gram-negatives. Antibiotics are the main determinants of the problem of resistance but also partially their vehicle. The solution of this problem includes infection control, diagnosis and adequate therapy (sufficient doses chosen according to the case and based on prefixed antibiotic politics). These antibiotic politics imply a rational use, reconsideration of the initial scheme according to microbiologic results, limited use of combination antimicrobial strategies, restricted list of drugs, rotation and correct use of prophylaxis.

Cross Infection↗
PubMed2000

Community-acquired pneumonia: etiology, epidemiology, and outcome at a teaching hospital in Argentina.

OBJECTIVE: To survey the etiology and epidemiology of community-acquired pneumonia (CAP) in relation to age, comorbidity, and severity and to investigate prognostic factors. DESIGN: Prospective epidemiologic study, single center. SETTING: University hospital at Buenos Aires, Argentina. PATIENTS: Outpatients and inpatients fulfilling clinical criteria of CAP. INTERVENTIONS: Systematic laboratory evaluation for determining the etiology, and clinical evaluation stratifying patients into mild, moderate, and severe CAP (groups 1 to 3), a clinical rule used for hospitalization. RESULTS: During a 12-month period, 343 patients (mean age, 64.4 years; range, 18 to 102 years) were evaluated. We found 167 microorganisms in 144 cases (yield, 42%). Streptococcus pneumoniae, the most common pathogen, was isolated in 35 cases (24%). Mycoplasma pneumoniae, present in 19 (13%), was second in frequency in group 1; Haemophilus influenzae, present in 17 cases (12%), was second in group 2; and Chlamydia pneumoniae, present in 12 cases (8%), was second in group 3. Etiology could not be determined on the basis of clinical presentation; identifying the etiology had no impact on mortality. Some findings were associated with specific causative organisms and outcome. A significantly lower number of nonsurvivors received adequate therapy (50% vs 77%). CONCLUSIONS: Age, comorbidities, alcohol abuse, and smoking were related with distinct etiologies. PaO(2) to fraction of inspired oxygen ratio < 250, aerobic Gram-negative pathogen, chronic renal failure, Glasgow score < 15, malignant neoplasm, and aspirative pneumonia were associated with mortality by multivariate analysis. Local microbiologic data could be of help in tailoring therapeutic guidelines to the microbiologic reality at different settings. The stratification schema and the clinical rule used for hospitalization were useful.

Adolescent↗
PubMed1999

Blood cultures have limited value in predicting severity of illness and as a diagnostic tool in ventilator-associated pneumonia.

STUDY OBJECTIVES: To define the usefulness of blood cultures for confirming the pathogenic microorganism and severity of illness in patients with ventilator-associated pneumonia (VAP). DESIGN: Prospective observational study using BAL and blood cultures collected within 24 h of establishing a clinical diagnosis of VAP. SETTING: A 15-bed medical and surgical ICU. PATIENTS: One hundred and sixty-two patients receiving mechanical ventilation hospitalized for > 72 h who had new or progressive lung infiltrate plus at least two of three clinical criteria for VAP. INTERVENTIONS: BAL and blood culture performed within 24 h of establishing a clinical diagnosis of VAP. MEASUREMENTS AND RESULTS: Ninety patients were BAL positive (BAL+), satisfying a microbiological definition of VAP (>/= 10(4) cfu/mL), 72 patients were BAL negative (BAL-). Bacteremia was diagnosed when at least two sets of blood cultures yielded a microorganism or when only one set was positive, but the same bacteria was present at a concentration >/= 10(4) cfu/mL in the BAL fluid. Bacteremia was significantly more frequent in the BAL+ than in the BAL- group (22/90 patients vs 5/72 patients; p = 0.006). In 6 of 22 BAL+ patients with bacteremia, an extrapulmonary site of infection was the source of bacteremia. Sensitivity of blood culture for disclosing the pathogenic microorganism in BAL+ patients was 26%, and the positive predictive value to detect the pathogen was 73%. Factors associated with mortality were age > 50 years, simplified acute physiology score > 14, prior inadequate antibiotic therapy, PaO(2)/fraction of inspired oxygen < 205, and use of H(2) blockers. By multivariate analysis, only the use of prior inadequate antimicrobial therapy (odds ratio [OR], 6.47) and age > 50 years (OR, 5.12) were independently associated with higher mortality. The rate of complications was not different in patients with bacteremia. CONCLUSIONS: Blood cultures have a low sensitivity for detecting the same pathogenic microorganism as BAL culture in patients with VAP. The presence of bacteremia does not predict complications, it is not related to the length of stay, and it does not identify patients with more severe illness. Inadequacy of prior antimicrobial therapy and age > 50 years were the only factors associated with mortality in a multivariate analysis. Blood cultures in patients with VAP are clearly useful if there is suspicion of another probable infectious condition, but the isolation of a microorganism in the blood does not confirm that microorganism as the pathogen causing VAP.

Adult↗
PubMed1999

[Use of trovafloxacin therapy in community-acquired pneumonia].

In community-acquired pneumonia (CAP) the pathogenic microorganism is unknown at the time of diagnosis. For that reason the antimicrobial therapy is empirical, based in the clinical picture and the presumptive causal microorganisms. Hospitalization is one of the most important decisions in patients with CAP. Clinical criteria appropriate to identifying those patients requiring hospital admission for antimicrobial administration and clinical control must be defined. The stratification of patients according to the presence of risk factors such as age and co-morbidities permit to predict which are the potential pathogenic microorganisms and their adequate therapy. Trovafloxacin covers all the presumed bacterial spectrum, pharmacokinetics, easiness to be administered and to pass to the oral route, advantageous for all the groups under consideration. Patients older than 65 years of age or with co-morbidities and those that need to be hospitalized receive clear benefits from this antibiotic.

Adult↗
PubMed1999

[Community-acquired pneumonia in the elderly requiring hospitalization. Clinical features and prognosis].

We evaluated retrospectively 96 patients older than 64 years admitted with the diagnosis of Community Acquired Pneumonia (CAP) in order to describe the clinical features, evaluate severity and assess prognostic factors. During an 18-month period 100 cases of CAP were included. Average age was 82.3 years +/- 8.3 (+/- SD). By the time of admission, cough and fever were found in 35% of cases and 48% had altered mental status. Fourteen per cent needed mechanical ventilation. Etiology was determined in 21% of cases. Most common pathogens were S. pneumoniae (38.1%), S. aureus (19%) and H. infuenzae (14.3%). Overall mortality was 29%. The most commonly present criteria of severity were tachypnea (respiratory rate > 30) and a PaO2/FIO2 ratio < 250. Severe pneumonia was found in 60% of patients and mortality in that group was 40%. Multivariate analysis demonstrated that some independent prognostic factors were associated with higher mortality: requirement of vasopressors (Odds Ratio [OR] = 22.0; 95% confidence interval [CI] = 1.9-249.5), oliguria (OR = 9.9; CI = 1.5-66.2), previous neurologic disease (OR = 8.2; CI = 1.8-36.6), PaCO2 > 44 mm/Hg (OR = 6.9; CI = 1.1-43.2), and creatinine > 1.4 mg/dl (OR = 4.7; CI = 1.2-19.1). We conclude that CAP features in elderly patients requiring hospitalization are atypical, severe presentations are frequent and mortality is high. Prognostic factors as found in this study can help the evaluating physician to identify those who require special care.

Aged↗
PubMed1997

Impact of BAL data on the therapy and outcome of ventilator-associated pneumonia.

STUDY OBJECTIVE: To define the impact of BAL data on the selection of antibiotics and the outcomes of patients with ventilator-associated pneumonia (VAP). DESIGN: Prospective observation and bronchoscopy with BAL, performed within 24 h of establishing a clinical diagnosis of a new episode of hospital-acquired VAP or progression of a prior episode of nosocomial pneumonia (NP). SETTING: A 15-bed medical and surgical ICU. PATIENTS: One hundred thirty-two patients hospitalized for more than 72 h, who were mechanically ventilated and had a new or progressive lung infiltrate plus at least two of the following three clinical criteria for VAP: abnormal temperature (> 38 degrees C or < 35 degrees C), abnormal leukocyte count (> 10,000/mm3 or < 3,000/mm3), purulent bronchial secretions. INTERVENTIONS: Bronchoscopy with BAL within 24 h of establishing a clinical diagnosis of VAP or progression of an infiltrate due to prior VAP or NP. All patients received antibiotics, 107 prior to bronchoscopy and 25 immediately after bronchoscopy. RESULTS: Sixty-five of the 132 patients were BAL positive (BAL[+]), satisfying a microbiologic definition of VAP (> 10(4) cfu/mL), while 67 were BAL negative (BAL[-]). The BAL(+) patients had no differences in mortality, prior antibiotic use, and demographic features when compared with the BAL(-) patients. More of the BAL(+) patients (38/65) satisfied all three clinical criteria of VAP than did BAL(-) patients (24/67) (p < 0.05). A total of 50 BAL(+) patients received antibiotic therapy prior to bronchoscopy, and when this prior therapy was adequate (n = 16), as defined by the results of BAL, then mortality was 38%, while if prior therapy was inadequate (n = 34), mortality was 91% (p < 0.001), and if no therapy was given (n = 15), mortality was 60%. When therapy changes were made after bronchoscopy, more patients (n = 42) received adequate therapy, but mortality in this group was comparable to mortality among those who continued to receive inadequate therapy (n = 23). A total of 46 of the 65 BAL(+) patients died, with 23 of these deaths occurring during the 48 h after the bronchoscopy, before BAL results were known. When BAL data became available, 37 of the 42 surviving patients received adequate therapy, but their mortality was comparable to the patients who continued to receive inadequate therapy. CONCLUSIONS: Patients with a strong clinical suspicion of VAP have a high mortality rate, regardless of whether BAL cultures confirm the clinical diagnosis of VAP. When adequate antibiotic therapy is initiated very early (ie, before performing bronchoscopy), mortality rate is reduced if this empiric therapy is adequate, compared to when this therapy is inadequate or no therapy is given. If adequate therapy is delayed until bronchoscopy is performed or until BAL results are known, mortality is higher than if it had been given at the time of first establishing a clinical diagnosis of VAP. When patients were changed from inadequate antibiotic therapy to adequate therapy, based on the results of BAL, mortality was comparable to those who continued to receive inadequate therapy. Thus, even if bronchoscopy can accurately define the microbial etiology of VAP, this information becomes available too late to influence survival.

Aged↗
PubMed1997

[Community-acquired pneumonia in adults. Clinical practice guideline for Argentina. Study Group on Community Acquired Pneumonia].

Community-acquired pneumonia (CAP) affects approximately 1% of the population annually. Initial antimicrobial therapy is most often empirical. Guidelines designed in other countries for the empirical management of CAP are not recommended for use in Argentina. Studies from other countries were considered together with unpublished local data to define the potential etiologic microorganisms and their antimicrobial susceptibility. Recommended diagnostic tests, groups of patients for different therapies and hospitalization criteria were defined. Severe CAP requiring intensive care was distinguished from the rest because of its distinct spectrum of etiologic agents and its high mortality, requiring a more focused therapy. Age, coexisting conditions and severity of illness were taken into account in the election of therapy.

Argentina↗
PubMed1985

Pulmonary lymphangiomyomatosis associated with tuberous sclerosis. Treatment with tamoxifen and tetracycline-pleurodesis.

A 44-year-old woman was seen with the clinical and histologic picture of lymphangiomyomatosis syndrome. She also had dermatologic and neurologic stigmata of tuberous sclerosis. After the development of a recurring chylothorax, she had a downhill course unresponsive to dietary, bronchodilator, corticosteroid and progesterone therapy. In an open lung specimen, the search for steroid receptor for estrogen was positive. The discovery in this case of an estrogen receptor represents important evidence for establishing an association between tuberous sclerosis and lymphangiomyomatosis. Tamoxifen therapy and tetracycline pleurodesis were successful in stopping the progressive course and controlling the chylothorax.

Adhesiveness↗