Impact of appropriate antimicrobial treatment on transition from ventilator-associated tracheobronchitis to ventilator-associated pneumonia

Introduction

Two small randomized controlled trials have suggested beneficial effects of antibiotic treatment in patients with ventilator-associated tracheobronchitis (VAT). The primary aim of this study is to determine the impact of appropriate antibiotic treatment on transition from VAT to ventilator-associated pneumonia (VAP) in critically ill patients. The secondary objective was to determine the incidence of VAP in patients with VAT.

Methods

This was a prospective observational multicenter study. All patients with a first episode of VAT were eligible. Patients with tracheostomy at intensive care unit (ICU) admission, and those with VAP prior to VAT were excluded. VAT was defined using all the following criteria: fever > 38°C with no other cause, purulent tracheal secretions, positive tracheal aspirate (≥10⁵ cfu/mL), and absence of new infiltrate on chest X ray. Only VAP episodes diagnosed during the 96 h following VAT, and caused by the same bacteria, were taken into account. Antibiotic treatment was at the discretion of attending physicians. Risk factors for transition from VAT to VAP were determined using univariate and multivariate analysis. All variables from univariate analysis with P values <0.1 were incorporated in the multivariate logistic regression analysis.

Results

One thousand seven hundred and ten patients were screened for this study. Eighty-six, and 123 patients were excluded for tracheostomy at ICU admission, and VAP prior to VAT; respectively. One hundred and twenty two (7.1%) patients were included. 17 (13.9%) patients developed a subsequent VAP. The most common microorganisms in VAT patients were Pseudomonas aeruginosa (30%), Staphylococcus aureus (18%), and Acinetobacter baumannii (10%). Seventy-four (60%) patients received antimicrobial treatment, including 58 (47.5%) patients who received appropriate antimicrobial treatment. Appropriate antibiotic treatment was the only factor independently associated with reduced risk for transition from VAT to VAP (OR [95% CI] 0.12[0.02-0.59], P = 0.009). The number of patients with VAT needed to treat to prevent one episode of VAP, or one episode of VAP related to P. aeruginosa was 5, and 34; respectively.

Conclusions

Appropriate antibiotic treatment is independently associated with reduced risk for transition from VAT to VAP.     

Oxidative stress in patients with obstructive sleep apnea syndrome

Purpose

We aimed to investigate whether systemic oxidative stress is increased in patients with obstructive sleep apnea syndrome (OSAS).

Methods

A total of 18 patients with severe OSAS and 13 controls were included in the study. Inclusion criteria for OSAS patients were: snoring and apnea–hypopnea index (AHI) of >30 in full polysomnography, no previous treatment for OSAS, non-smoking status, and a medical history of being free of comorbidities known to increase oxidative stress. Controls were recruited among subjects assessed for snoring in the Sleep Laboratory Department if they had AHI<5. At baseline, patients were evaluated by the Epworth Sleepiness Scale and underwent spirometry, echocardiography, and full polysomnographic study. Blood samples were collected for evaluation of oxidative stress biomarkers [protein carbonyls, reduced (GSH) and oxidized (GSSG) glutathione, 8-isoprostane, thiobarbituric acid-reactive substances (TBARS), catalase activity, Cu–Zn superoxide dysmutase (SOD), total antioxidant capacity (TAC)] before and on the morning following polysomnography.

Results

The overnight (morning–night) change (%) of GSH/GSSG ratio and GSH was significantly different between OSAS and controls (p?=?0.03 and p?=?0.048, respectively). Plasma protein carbonyls, erythrocyte catalase activity, 8-isoprostane, SOD, TBARS, and TAC plasma values were not different between OSAS and controls (p?>?0.05). No significant correlation was found between changes in the levels of biomarkers and AHI, arousal, or desaturation index.

Conclusion

The present prospective investigation in a population free of comorbidities or factors which may increase systemic oxidative stress provides evidence that obstructive sleep apnea per se might be associated with increased oxidative burden possibly via GSH/GSSG pathway.     

Recombinant methionyl human leptin therapy in replacement doses improves insulin resistance and metabolic profile in patients with lipoatrophy and metabolic syndrome induced by the highly active antiretroviral therapy

CONTEXT: Highly active antiretroviral therapy (HAART) for HIV-1 infection has been associated with a metabolic syndrome characterized by insulin resistance, hyperlipidemia, and redistribution of body fat (lipodystrophy). A subset of patients with predominant lipoatrophy has low levels of the adipocyte-secreted hormone leptin. OBJECTIVE: The objective of the study was to assess whether administration of recombinant methionyl human leptin (r-metHuLeptin) improves insulin resistance and other metabolic abnormalities in HIV+ leptin-deficient subjects with HAART-induced lipoatrophy. DESIGN, SETTING, PATIENTS, AND INTERVENTION: We conducted a randomized, placebo-controlled, double-blinded, crossover study from 2002 to 2004 in seven HIV+ men with HAART-induced lipoatrophy, serum leptin level less than 3 ng/ml, and fasting triglyceride level greater than 300 mg/dl, who were administered placebo for 2 months before or after administration of r-metHuLeptin at physiological doses for an additional 2 months. MAIN OUTCOME MEASURES: Insulin resistance, lipid levels, inflammatory markers, body composition, and HIV control were measured. RESULTS: Compared with placebo, r-metHuLeptin therapy improved fasting insulin levels, insulin resistance (as expressed by the homeostasis model assessment index and an insulin suppression test), and high-density lipoprotein. Body weight and fat mass decreased on r-metHuLeptin, mainly due to a decrease in truncal fat but not peripheral fat or lean body mass. r-metHuLeptin was well tolerated, and HIV control was not adversely affected. CONCLUSIONS: r-metHuLeptin replacement at physiological doses in HIV+ leptin-deficient patients with HAART-induced lipoatrophy improves insulin resistance, high-density lipoprotein, and truncal fat mass. Future larger and more long-term studies in HAART-induced lipoatrophy, including patients with more severe metabolic abnormalities, are warranted to evaluate the physiological and potentially therapeutic role of r-metHuLeptin for this condition and to fully clarify the underlying mechanisms of action.     

Unilateral pulmonary edema due to pulmonary venous obstruction from fibrosing mediastinitis

An unusual case of fibrosing mediastinitis with obstruction of the inferior and superior left pulmonary veins and severe narrowing of the right pulmonary artery, disclosed after unilateral pulmonary edema, is described. The 18-year-old male patient had a long history of cough, progressive dyspnea and recurrent hemoptysis and the possible diagnosis of "interstitial fibrosis" from a previous lung biopsy. The diagnosis and the pulmonary vessels involvement were suspected after right heart catheterization combined with transesophageal echocardiography and confirmed during urgent thoracotomy and at postmortem examination.     

CT demonstration of normal gastric wall thickness: The value of administering gasproducing and paralytic agents

The: authors analysed the CT-findings in 100 normal subjects who underwent a modified doublecontrast technique (D.C.). The mean gastric wall thickness in four areas was measured and the contribution of the D.C. technique is discussed.     

Huge biatrial primary cardiac B-cell lymphoma resulting in bilateral atrioventricular valve obstruction

We report the case of a 48-year-old man with a clinical syndrome caused by both pulmonary and systemic venous congestion. Echocardiography indicated a huge tumor occupying both dilated atria almost completely, seeming to invade from the atrial septum. A test for HIV was negative. Our primary diagnosis was a biatrial myxoma. Urgent surgery was performed disclosing large cell B-cell primary cardiac lymphoma. The patient died 8 days later. Primary cardiac lymphoma is extremely rare in immunocompetent patients. Its rarity and heterogenous clinical presentation make diagnosis difficult. As tissue characterization is still beyond the capabilities of currently available echocardiography, a combination of examinations are indicated, when the clinical condition is relatively stable, in order to reach the exact diagnosis.     

A phase III study of 5-fluorouracil versus 5-fluorouracil plus interferon alpha 2b versus 5-fluorouracil plus leucovorin in patients with advanced colorectal cancer: a Hellenic Cooperative Oncology Group (HeCOG) study

We conducted a phase III study in patients with advanced colorectal carcinoma (ACC). The total number of patients randomized from October 1993 until July 1998 was 192, whereas therapy was started on 179 and 158 (82.3%) have been evaluable. The treatment schedules consisted of weekly bolus administration for 6 weeks of 5-fluorouracil (5-FU), 600 mg/m2 (arm I) versus 5-FU (500 mg/m2) intravenous bolus and interferon-alpha, 5 MU subcutaneously, three times a week (arm II) versus leucovorin 200 mg/m2 in 2-hour infusion and 5-FU 500 mg/m2 intravenous bolus at the midtime of leucovorin infusion (arm III) followed by a 2-week rest period. Treatment was continued for six cycles or until progression. This study failed to show any superiority of the modulated 5-FU versus single administration of 5-FU. There were no significant differences between the three arms in the overall response rate (10.3% versus 11.3% versus 12.9%, p = 0.95), the time to tumor progression (median, 3.9 versus 3.8 versus 6.0 months, p = 0.59), or survival duration (median, 14.7 versus 12.4 versus 16.3 months, p = 0.71). The incidence of severe (grades III and IV) toxicity was significantly higher in patients in arm II and III (24.5% and 18.6%) versus arm I (6.0%) (p = 0.01). Because modulated 5-FU failed to show superiority versus 5-FU, new agents and new strategies are needed for the treatment of advanced colorectal carcinoma.     

Device-associated nosocomial infection rates in intensive care units in Greece.

Site-specific, risk-adjusted incidence rates of intensive care unit (ICU)-acquired infections were obtained through standardized surveillance in 8 ICUs in Greece. High rates were observed for central line-associated bloodstream infection (12.1 infections per 1,000 device-days) and ventilator-associated pneumonia (12.5 infections per 1,000 device-days). Gram-negative microorganisms accounted for 60.4% of the isolates recovered, and Acinetobacter species were predominant. To reduce infection rates in Greek ICUs, comprehensive infection control programs are required.