Login to your account

Username *
Password *
Remember Me

Blog With Right Sidebar

    Vous êtes ici :  
  1. Accueil
  2. Blog With Right Sidebar

Extensive drug resistance acquired during treatment of multidrug-resistant tuberculosis.

Increasing access to drugs for the treatment of multidrug-resistant (MDR) tuberculosis (TB) is crucial but could lead to increasing resistance to these same drugs. In 2000, the international Green Light Committee (GLC) initiative began to increase access while attempting to prevent acquired resistance.

SUBJECTS AND METHODS:  To assess the GLC's impact, we followed adults with pulmonary MDRTB from the start to the end of treatment with monthly sputum cultures, drug susceptibility testing, and genotyping. We compared the frequency and predictors of acquired resistance to second-line drugs (SLD) in nine countries that volunteered to participate, five countries that met GLC criteria and four countries that did not apply to the GLC.

RESULTS:  In total, 832 subjects were enrolled. Of those without baseline resistance to specific SLDs, 68 (8.9%) acquired extensively drug-resistant (XDR) TB, 79 (11.2%) acquired fluoroquinolone (FQ) resistance, and 56 (7.8%) acquired resistance to second-line injectable drugs (SLI). The relative risk (95% confidence interval) of acquired resistance was lower at GLC-approved sites: 0.27 (0.16,0.47) for XDRTB, 0.28 (0.17,0.45) for FQ, and 0.15 (0.06,0.39) to 0.60 (0.34,1.05) for three different SLI. The risk increased as the number of potentially effective drugs decreased. Controlling for baseline drug resistance and differences between sites, the odds ratios were 0.21 (0.07,0.62) for acquired XDRTB and 0.23 (0.09,0.59) for acquired FQ resistance.

CONCLUSIONS:  Treatment of MDRTB involves substantial risk of acquired resistance to SLD, increasing as baseline drug resistance increases. The risk was significantly lower in programs documented by the GLC to meet specific standards.

Lung transplantation for interstitial lung diseases.

Related Articles

An overview over the role of lung transplantation in interstitial lung diseases will be given.

RECENT FINDINGS: Lung transplantation is an established therapy option for patients with various end-stage lung diseases. Currently, the worldwide procedural frequency is about 3600 per year. Unfortunately, the shortage of donor organs leads to approximately every sixth patient in western countries dying before a donor organ is available. The most frequent underlying clinical indications are emphysema, pulmonary fibrosis, and cystic fibrosis. In a recent registry report worldwide, 23% of all lung transplant recipients had a diagnosis of idiopathic pulmonary fibrosis. In experienced centers, candidates for transplantation are chosen according to disease-specific factors after excluding contra-indications. However, there are several challenges for lung transplantation. The number of lung transplantations performed is limited by the supply of donor organs, and the long-term survival rates are still inferior compared with other forms of solid organ transplantation.

SUMMARY: Lung transplantation offers a survival benefit in carefully selected patients with interstitial lung diseases.

Safety and feasibility of antibiotic de-escalation in bacteremic pneumonia.

Related Articles

Antibiotic de-escalation is a potential strategy advocated to conserve the effectiveness of broad-spectrum antibiotics. The aim of this study was to examine the safety and feasibility of antibiotic de-escalation in patients admitted with bacteremic pneumonia.

METHODS: A retrospective chart review was done for patients with bacteremic pneumonia admitted to Northwest Texas Hospital in Amarillo, TX, USA, during 2008. Antibiotic de-escalation was defined as changing the empiric antibiotic regimen to a culture-directed single agent with a narrower spectrum than the original regimen.

RESULTS: Sixty-eight patients were admitted with bacteremic pneumonia. Eight patients were not eligible for de-escalation. Among the 60 patients who were eligible for de-escalation, the treating physicians failed to de-escalate antibiotics in 27 cases (45.0%). Discharge to a long-term care facility predicted failure to de-escalate antibiotics, while an infectious diseases consultation was significantly associated with antibiotic de-escalation. The average daily cost of antibacterial therapy in the de-escalation group was $25.7 compared with $61.6 in the group where de-escalation was not implemented. The difference in mean length of hospital stay and mortality between the two groups was not statistically significant.

CONCLUSION: Antibiotic de-escalation is a safe management strategy but unfortunately is not widely adopted. Although bacterial resistance poses a significant threat and is rising, antimicrobial de-escalation has emerged as a potential intervention that can conserve the effectiveness of broad-spectrum antibiotics without compromising the patient's outcome. This practice is becoming important in the face of slow development of new anti-infective agents.

Gas exchange and ventilation-perfusion relationships in the lung.

Related Articles

This review provides an overview of the relationship between ventilation/perfusion ratios and gas exchange in the lung, emphasising basic concepts and relating them to clinical scenarios. For each gas exchanging unit, the alveolar and effluent blood partial pressures of oxygen and carbon dioxide (PO2 and PCO2 ) are determined by the ratio of alveolar ventilation to blood flow (V'A/Q') for each unit. Shunt and low V'A/Q' regions are two examples of V'A/Q' mismatch and are the most frequent causes of hypoxaemia.

Diffusion limitation, hypoventilation and low inspired PO2 cause hypoxaemia, even in the absence of V'A/Q' mismatch. In contrast to other causes, hypoxaemia due to shunt responds poorly to supplemental oxygen. Gas exchanging units with little or no blood flow (high V'A/Q' regions) result in alveolar dead space and increased wasted ventilation, i.e. less efficient carbon dioxide removal. Because of the respiratory drive to maintain a normal arterial PCO2 , the most frequent result of wasted ventilation is increased minute ventilation and work of breathing, not hypercapnia. Calculations of alveolar-arterial oxygen tension difference, venous admixture and wasted ventilation provide quantitative estimates of the effect of V'A/Q' mismatch on gas exchange.

The types of V'A/Q' mismatch causing impaired gas exchange vary characteristically with different lung diseases.

Smoking-related idiopathic interstitial pneumonia.

Related Articles

Cigarette smoking is a key factor in the development of numerous pulmonary diseases. An international group of clinicians, radiologists and pathologists evaluated patients with previously identified idiopathic interstitial pneumonia (IIP) to determine unique features of cigarette smoking.

Phase 1 (derivation group) identified smoking-related features in patients with a history of smoking (n = 41). Phase 2 (validation group) determined if these features correctly predicted the smoking status of IIP patients (n = 100) to participants blinded to smoking history. Finally, the investigators sought to determine if a new smoking-related interstitial lung disease phenotype could be defined.

Phase 1 suggested that preserved forced vital capacity with disproportionately reduced diffusing capacity of the lung for carbon monoxide, and various radiographic and histopathological findings were smoking-related features. In phase 2, the kappa coefficient among clinicians was 0.16 (95% CI 0.11-0.21), among the pathologists 0.36 (95% CI 0.32-0.40) and among the radiologists 0.43 (95% CI 0.35-0.52) for smoking-related features. Eight of the 100 cases were felt to represent a potential smoking-related interstitial lung disease. Smoking-related features of interstitial lung disease were identified in a minority of smokers and were not specific for smoking.

This study is limited by its retrospective design, the potential for recall bias in smoking history and lack of information on second-hand smoke exposure. Further research is needed to understand the relationship between smoking and interstitial lung disease.

Search

Search