Girish B. Nair

Community-Acquired Pneumonia: An Unfinished Battle

Community-acquired pneumonia remains a common illness with substantial morbidity and mortality. Current management challenges focus on identifying the likely etiologic pathogens based on an assessment of host risk factors, while attempting to make a specific etiologic diagnosis, which is often not possible. Therapy is necessarily empiric and focuses on pneumococcus and atypical pathogens for all patients, with consideration of other pathogens based on specific patient risk factors. It is important to understand the expected response to effective therapy, and to identify and manage clinical failure at the earliest possible time point. Prevention is focused on smoking cessation and vaccination against pneumococcus and influenza.

Nosocomial Pneumonia: Lessons Learned

Nosocomial pneumonia remains a significant cause of hospital-acquired infection, imposing substantial economic burden on the health care system worldwide. Various preventive strategies have been increasingly used to prevent the development of pneumonia. It is now recognized that patients with health care-associated pneumonia are a heterogeneous population and that not all are at risk for infection with nosocomial pneumonia pathogens, with some being infected with the same organisms as in community-acquired pneumonia. This review discusses the risk factors for nosocomial pneumonia, controversies in its diagnosis, and approaches to the treatment and prevention of nosocomial and health care-associated pneumonia.

Pharmacologic Agents for Mucus Clearance in Bronchiectasis

There are no approved pharmacologic agents to enhance mucus clearance in non-cystic fibrosis (CF) bronchiectasis. Evidence supports the use of hyperosmolar agents in CF, and studies with inhaled mannitol and hypertonic saline are ongoing in bronchiectasis. N-acetylcysteine may act more as an antioxidant than a mucolytic in other lung diseases. Dornase α is beneficial to patients with CF, but is not useful in patients with non-CF bronchiectasis. Mucokinetic agents such as β-agonists have the potential to improve mucociliary clearance in normals and many disease states, but have not been adequately studied in patients with bronchiectasis.

Eosinophilic Pneumonia Associated With Azacitidine in a Patient With Myelodysplastic Syndrome

Eosinophilic pneumonia is characterized by cough, lung infiltrates on imaging, and by the presence of eosinophils in the alveoli and pulmonary interstitium. Azacitidine, a pyramidine nucleoside analog of cytidine, is FDA approved for the treatment of various myelodysplastic syndromes. We present a case of a 76-year-old man with recently diagnosed myelodysplastic syndrome, who developed eosinophilic pneumonia after initiating therapy with azacitidine. There was clinical and radiographic improvement with cessation of the drug and treatment with prednisone. Diagnosis of drug-induced eosinophilic pneumonia is established by having a temporal relationship between onset of symptoms and initiation of therapy, bronchoalveolar lavage or lung biopsy evidence of pulmonary eosinophilia, no other explanation for the disease, and improvement upon cessation of the offending agent. Our case illustrates the need for a high index of suspicion to identify adverse pulmonary reactions associated with newly developed medications.

Year in review 2013: critical care - respiratory infections

Over the last two decades, considerable progress has been made in the understanding of disease mechanisms and infection control strategies related to infections, particularly pneumonia, in critically ill patients. Patient-centered and preventative strategies assume paramount importance in this era of limited health-care resources, in which effective targeted therapy is required to achieve the best outcomes. Risk stratification using severity scores and inflammatory biomarkers is a promising strategy for identifying sick patients early during their hospital stay. The emergence of multidrug-resistant pathogens is becoming a major hurdle in intensive care units. Cooperation, education, and interaction between multiple disciplines in the intensive care unit are required to limit the spread of resistant pathogens and to improve care. In this review, we summarize findings from major publications over the last year in the field of respiratory infections in critically ill patients, putting an emphasis on a newer understanding of pathogenesis, use of biomarkers, and antibiotic stewardship and examining new treatment options and preventive strategies.

Ergonomics in bronchoscopy: is there a need for better design or a change in the work environment?

The field of conventional bronchoscopy has undergone a paradigm shift over the last decade. The ability to visualize peribronchial structures in real time has increased the diagnostic and therapeutic scope of flexible bronchoscopy. Ultrasound engineering and the development of a probe with an interface capable of sound wave transmission, has led to the development of a new procedure, endobronchial ultrasound, which has been widely adapted, both throughout the USA and worldwide [1]. Similarly, techniques such as electromagnetic navigation bronchoscopy, autofluorescence bronchoscopy, optical coherence tomography and other interventional procedures, including bronchial thermoplasty, cryotherapy, brachytherapy, balloon dilatation and stent are increasingly being adopted at large academic centers [2]. Flexible bronchoscopy is an effective alternative to rigid bronchoscopy in treating distal airway lesions and less advanced malignant lesions [3]. The emphasis with all of these procedures is to reduce procedurerelated complications and improve patient comfort. However, the additional physical strain and exposure to cumulative trauma on the person actually performing the procedure is often overlooked. The prolonged nature of the procedures combined with unusual postures can result in overuse injuries, such as carpal tunnel syndrome, tendonitis, epicondilitis, neck sprain, shoulder pain and DeQuervain’s tenosynovitis. These injuries may be common in bronchoscopists performing a high number of these procedures. Minimal research has been carried out in this regard, and the available data to measure the magnitude of this problem are scarce.

Critical Care Echocardiography: Pericardial Disease, Tamponade, and Other Topics

Pericardial effusion with tamponade physiology is an underrecognized and life-threatening but treatable cause of hemodynamic impairment in the critical care setting. As fluid accumulates in the pericardial space, the pericardial pressure exceeds the intracardiac pressure and diminishes cardiac output. Goal-directed critical care echocardiography performed at the bedside can promptly detect a pericardial effusion, which is visualized as an echo-free space surrounding the heart. In the proper clinical context, echocardiographic signs of tamponade, such as diastolic collapse of the right-sided chambers and plethora of the inferior vena cava, can help to establish the diagnosis of cardiac tamponade. This chapter will review technical considerations, imaging acquisition and interpretation, and pitfalls in the critical care ultrasound assessment of pericardial effusion and tamponade.

Critical Care Echocardiography: Acute Left Ventricular and Valvular Dysfunction

A rapid bedside critical care echocardiography (CCE) exam performed by an intensivist can provide an accurate dynamic assessment of left ventricular (LV) and valvular function and accordingly help direct resuscitative efforts. Basic CCE is goal oriented and uses five basic views (parasternal long and short axis, apical four-chamber, subxiphoid, and inferior vena cava views). The focus with basic CCE is to identify major, catastrophic causes of left ventricular failure or valve dysfunction that would affect the hemodynamic status of the critically ill patient. Advanced CCE, on the other hand, requires a comprehensive evaluation of hemodynamic parameters, mastery over image acquisition, and complete understanding of Doppler evaluation. The global visual assessment is the most common method used to estimate LV systolic function. LV systolic function can be categorized as normal, hyperdynamic, moderate dysfunction, or severe dysfunction. The estimation of stroke volume (SV) and cardiac output (CO) by echocardiography can also be a useful method for the assessment of LV systolic function in the critically ill patient. Valve function can be assessed using 2D echocardiography and color Doppler. Although goal-directed echocardiography can be invaluable in the care of critically ill patients, it is also paramount to recognize common pitfalls of CCE that can lead to flawed interpretations. With proper training and competence, intensivists can incorporate the findings from CCE into bedside clinical management strategies.

Ventilator-associated pneumonia prevention: response to Silvestri et al.

Dear Editor, We have read the comments of Silvestri et al. [1] and appreciate their interest in our article [2]. We agree that the data supporting SDD are strong, as described in a recent metaanalysis [3]. However, as they acknowledged, space limitations prevented us from discussing all topics, including SDD. In our review, we did allude to the principles of SDD when we commented that microaspiration of oropharyngeal contents, contaminated by endogenous flora, is a target of several prevention interventions. However, we did not, as Silvestri et al. suggest, omit further discussion of SDD because of there being no uncertainty about its value. In fact, there is an ongoing debate and uncertainty about possible benefits and harms related to SDD and its implementation [4, 5]. When discussing prevention in our review, we did comment on the controversy about ‘‘zero VAP’’. In many ICUs, the use of ventilator bundles, which often include oral care (sometimes with chlorhexidine gluconate), has dramatically reduced (but not eliminated) the frequency of VAP. In this setting, the incremental utility of SDD remains uncertain. Many of the studies of SDD were done in an era when VAP rates were high, and ventilator bundles and routine oral care were not utilized. We believe that the mortality benefit of SDD in ICUs that routinely use ventilator bundles, have low rates of VAP, but high rates of MDR pathogens, still needs to be demonstrated, to justify using the widespread use of this strategy.