MD Conference Express ATS 2013 - (Page 26)

SELECTED UPDATES ON VENTILATOR-ASSISTED PNEUMONIA Improving Outcomes of Ventilator-Associated Pneumonia Written by Wayne Kuznar Official Peer-Reviewed Highlights From 26 July 2013 Nosocomial pneumonia, especially ventilator-associated pneumonia (VAP), is a major cause of morbidity and mortality in the intensive care unit (ICU). Mark L. Metersky, MD, University of Connecticut School of Medicine, Farmington, Connecticut, USA, provided an update on bacterial resistance relevant to VAP, with a focus on methicillinresistant Staphylococcus aureus (MRSA). Vancomycin-resistant S. aureus is rare (limited to case reports) but the prevalence of vancomycin-intermediate S. aureus (VISA) is probably increasing. Heteroresistant VISA (hVISA) is challenging to detect; using population analysis profiling area under the curve (AUC) as a reference method, the hVISA phenotype can be detected for strains of S. aureus with vancomycin minimum inhibitory concentration (MIC) levels as low as 0.5 μg/mL [Howden BP et al. Clin Microbiol Rev 2010; Musta AC et al. J Clin Microbiol 2009]. Vancomycin MIC “creep” refers to an increase in the frequency of MICs approaching 2 μg/mL, considered to be the cutoff for vancomycin sensitivity. The significance of the MIC creep is not clear, as studies assessing the impact of vancomycin treatment on response have produced variable results. Regional variation in the contribution of MRSA to S. aureus VAP is marked. In the United States and Europe, the prevalence of MRSA seems to have stabilized, although at various levels depending upon the country studied. Gram-negative resistance in VAP continues to increase, but like MRSA, the prevalence across the world varies widely. For example, Acinetobacter sp. cause approximately 5% of VAP in the United States [Jones RN. Clin Infect Dis 2010] and ~35% in Asia)[Chung DR et al. Am J Respir Crit Care 2011]. This organism is typically multi-drug resistant. Klebsiella pneumoniae is a Gram-negative organism that is increasingly resistant to carbapenems; several other Gram-negative Enterobacteriaceae and non-Enterobacteriaceae also produce carbapenemases. In vitro ertapenem resistance suggests K. pneumoniae carbapenemase with resulting imipenem and meropenem resistance despite in vitro susceptibility, said Dr. Metersky. Antibiotic stewardship is necessary to help limit the development of resistant strains in the hospital. The elements of stewardship include treating infection and not treating colonization, determining the infecting organism, initial appropriate antibiotic therapy at a sufficient dose, deescalation, and avoiding excessive length of therapy. Michael S. Niederman, MD, Winthrop University Hospital, Mineola, New York, USA, discussed treating MRSA pneumonia in the ICU, noting that resistance is a risk factor for mortality. Even with appropriate therapy with vancomycin, mortality for those with MRSA VAP was 48% in one series of 75 cases, which was double the risk of mortality compared with controls [Rello J et al. Crit Care Med 2005]. In a subset of patients who received continuous-infusion vancomycin, however, the mortality rate declined to half compared with those treated with intermittent vancomycin, which suggests that attributable mortality of MRSA VAP could be lowered with better therapies. Other studies show longer length of stay [Shorr AF et al. Crit Care Med 2006] and slower resolution of MRSA VAP than other forms of pneumonia, despite appropriate treatment (Figure 1) [Vidaur L et al. Chest 2008]. Combination therapy is needed to optimize treatment of Gram-negative bacteria in VAP, and usually requires a b-lactam antibiotic with an aminoglycoside. In 2013, MRSA must be considered when selecting therapy in virtually every patient on a ventilator who develops nosocomial pneumonia, said Dr. Niederman. With rising MIC levels for vancomycin, optimizing drug dosing is essential, although even optimization may not lead to good outcomes if the vancomycin MIC is >1 μg/mL, and aggressive vancomycin dosing may promote nephrotoxicity [Lodise TP et al. Clin Infect Dis 2009]. For proven MRSA VAP, linezolid may offer advantages over optimally dosed vancomycin. In a head-to-head, randomized, double-blind comparison, clinical response at end of study was significantly higher with linezolid than with vancomycin dosed optimally in the treatment of www.mdconferencexpress.com  http://www.mdconferencexpress.com

Table of Contents for the Digital Edition of MD Conference Express ATS 2013

MD Conference Express ATS 2013
Contents
Prevention and Early Treatment of Acute Lung Injury
Nocturnal Noninvasive Ventilation Improves Outcomes in Multiple Disorders
Hospital Readmissions: Challenges and Opportunities
EBUS-TBNA: Accurate and Safe for Detecting Sarcoidosis
Data Link Obstructive Sleep Apnea and Type 2 Diabetes
Statin Use Improves Respiratory-Related Mortality in Patients With COPD
Addition of Spironolactone to Ambrisentan May Be a Novel Treatment Strategy to Improve Outcome in Patients With PAH
Haloperidol Does Not Prevent Delirium in Ventilated ICU Patients
Beraprost Plus Sildenafil Effective in Pulmonary Arterial Hypertension
Dupilumab Is Safe and Effective for Controlling Asthma Attacks
Once-Daily QVA149 Improves Breathlessness in COPD Patients
CPAP in CVD and OSA Does Not Significantly Improve Cardiovascular Biomarkers
CPAP Reduces BP in Patients With Resistant Hypertension and Obstructive Sleep Apnea
Effects of Obesity on COPD
Pulmonary Embolism
Ventilator-Associated Pneumonia
Lung Cancer Screening
Idiopathic Pulmonary Fibrosis
Non-Small-Cell Lung Cancer

MD Conference Express ATS 2013

https://www.nxtbook.com/nxtbooks/md_conference_express/ats2013
https://www.nxtbookmedia.com