Nilam J. Soni

Procalcitonin‐guided antibiotic therapy: A systematic review and meta‐analysis

BACKGROUND The utility of procalcitonin to manage patients with infections is unclear. A systematic review of comparative studies using procalcitonin-guided antibiotic therapy in patients with infections was performed. METHODS Randomized, controlled trials comparing procalcitonin-guided initiation, intensification, or discontinuation of antibiotic therapy to clinically guided therapy were included. Outcomes were antibiotic usage, morbidity, and mortality. MEDLINE, EMBASE, the Cochrane Database, National Institute for Clinical Excellence, the National Guideline Clearinghouse, and the Health Technology Assessment Programme were searched from January 1, 1990 to December 16, 2011. RESULTS Eighteen randomized, controlled trials were included. Data were pooled into clinically similar patient populations. In adult intensive care unit (ICU) patients, procalcitonin-guided discontinuation of antibiotics reduced antibiotic duration by 2.05 days (95% confidence interval [CI]: -2.59 to -1.52) without increasing morbidity or mortality. In contrast, procalcitonin-guided intensification of antibiotics in adult ICU patients increased antibiotic usage and morbidity. In adult patients with respiratory tract infections, procalcitonin guidance significantly reduced antibiotic duration by 2.35 days (95% CI: -4.38 to -0.33), antibiotic prescription rate by 22% (95% CI: -41% to -4%), and total antibiotic exposure without affecting morbidity or mortality. A single, good quality study of neonates with suspected sepsis demonstrated reduced antibiotic duration by 22.4 hours (P = 0.012) and reduced the proportion of neonates on antibiotics for ≥ 72 hours by 27% (P = 0.002) with procalcitonin guidance. CONCLUSION Procalcitonin guidance can safely reduce antibiotic usage when used to discontinue antibiotic therapy in adult ICU patients and when used to initiate or discontinue antibiotics in adult patients with respiratory tract infections.

Ultrasound in the diagnosis and management of pleural effusions

We review the literature on the use of point-of-care ultrasound to evaluate and manage pleural effusions. Point-of-care ultrasound is more sensitive than physical exam and chest radiography to detect pleural effusions, and avoids many negative aspects of computerized tomography. Additionally, point-of-care ultrasound can assess pleural fluid volume and character, revealing possible underlying pathologies and guiding management. Thoracentesis performed with ultrasound guidance has lower risk of pneumothorax and bleeding complications. Future research should focus on the clinical effectiveness of point-of-care ultrasound in the routine management of pleural effusions and how new technologies may expand its clinical utility.

Severe Pneumococcal Pneumonia Causes Acute Cardiac Toxicity and Subsequent Cardiac Remodeling

Rationale: Up to one‐third of patients hospitalized with pneumococcal pneumonia experience major adverse cardiac events (MACE) during or after pneumonia. In mice, Streptococcus pneumoniae can invade the myocardium, induce cardiomyocyte death, and disrupt cardiac function following bacteremia, but it is unknown whether the same occurs in humans with severe pneumonia. Objectives: We sought to determine whether S. pneumoniae can (1) translocate the heart, (2) induce cardiomyocyte death, (3) cause MACE, and (4) induce cardiac scar formation after antibiotic treatment during severe pneumonia using a nonhuman primate (NHP) model. Methods: We examined cardiac tissue from six adult NHPs with severe pneumococcal pneumonia and three uninfected control animals. Three animals were rescued with antibiotics (convalescent animals). Electrocardiographic, echocardiographic, and serum biomarkers of cardiac damage were measured (troponin T, N‐terminal pro‐brain natriuretic peptide, and heart‐type fatty acid binding protein). Histological examination included hematoxylin and eosin staining, immunofluorescence, immunohistochemistry, picrosirius red staining, and transmission electron microscopy. Immunoblots were used to assess the underlying mechanisms. Measurements and Main Results: Nonspecific ischemic alterations were detected by electrocardiography and echocardiography. Serum levels of troponin T and heart‐type fatty acid binding protein were increased (P < 0.05) after pneumococcal infection in both acutely ill and convalescent NHPs. S. pneumoniae was detected in the myocardium of all NHPs with acute severe pneumonia. Necroptosis and apoptosis were detected in the myocardium of both acutely ill and convalescent NHPs. Evidence of cardiac scar formation was observed only in convalescent animals by transmission electron microscopy and picrosirius red staining. Conclusions: S. pneumoniae invades the myocardium and induces cardiac injury with necroptosis and apoptosis, followed by cardiac scarring after antibiotic therapy, in an NHP model of severe pneumonia.

Point-of-Care Ultrasonography for Primary Care Physicians and General Internists

Point-of-care ultrasonography (POCUS) is a safe and rapidly evolving diagnostic modality that is now utilized by health care professionals from nearly all specialties. Technological advances have improved the portability of equipment, enabling ultrasound imaging to be executed at the bedside and thereby allowing internists to make timely diagnoses and perform ultrasound-guided procedures. We reviewed the literature on the POCUS applications most relevant to the practice of internal medicine. The use of POCUS can immediately narrow differential diagnoses by building on the clinical information revealed by the traditional physical examination and refining clinical decision making for further management. We describe 2 common patient scenarios (heart failure and sepsis) to highlight the impact of POCUS performed by internists on efficiency, diagnostic accuracy, resource utilization, and radiation exposure. Using POCUS to guide procedures has been found to reduce procedure-related complications, along with costs and lengths of stay associated with these complications. Despite several undisputed advantages of POCUS, barriers to implementation must be considered. Most importantly, the utility of POCUS depends on the experience and skills of the operator, which are affected by the availability of training and the cost of ultrasound devices. Additional system barriers include availability of templates for documentation, electronic storage for image archiving, and policies and procedures for quality assurance and billing. Integration of POCUS into the practice of internal medicine is an inevitable change that will empower internists to improve the care of their patients at the bedside.

Global initiative for meticillin-resistant Staphylococcus aureus pneumonia (GLIMP): an international, observational cohort study.

BACKGROUND Antibiotic resistance is a major global health problem and pathogens such as meticillin-resistant Staphylococcus aureus (MRSA) have become of particular concern in the management of lower respiratory tract infections. However, few data are available on the worldwide prevalence and risk factors for MRSA pneumonia. We aimed to determine the point prevalence of MRSA pneumonia and identify specific MRSA risk factors in community-dwelling patients hospitalised with pneumonia. METHODS We did an international, multicentre study of community-dwelling, adult patients admitted to hospital with pneumonia who had microbiological tests taken within 24 h of presentation. We recruited investigators from 222 hospitals in 54 countries to gather point-prevalence data for all patients admitted with these characteristics during 4 days randomly selected during the months of March, April, May, and June in 2015. We assessed prevalence of MRSA pneumonia and associated risk factors through logistic regression analysis. FINDINGS 3702 patients hospitalised with pneumonia were enrolled, with 3193 patients receiving microbiological tests within 24 h of admission, forming the patient population. 1173 (37%) had at least one pathogen isolated (culture-positive population). The overall prevalence of confirmed MRSA pneumonia was 3·0% (n=95), with differing prevalence between continents and countries. Three risk factors were independently associated with MRSA pneumonia: previous MRSA infection or colonisation (odds ratio 6·21, 95% CI 3·25-11·85), recurrent skin infections (2·87, 1·10-7·45), and severe pneumonia disease (2·39, 1·55-3·68). INTERPRETATION This multicountry study shows low prevalence of MRSA pneumonia and specific MRSA risk factors among community-dwelling patients hospitalised with pneumonia. FUNDING None.

Use of ultrasound guidance for central venous catheterization: a national survey of intensivists and hospitalists

PURPOSE The purpose of the study is to evaluate the frequency and barriers to use of ultrasound guidance for central venous catheter (CVC) insertion by physicians specializing in critical care and hospital medicine. MATERIALS AND METHODS A national cross-sectional electronic survey of intensivists and hospitalists was administered from November 2014 to January 2015. RESULTS The survey response rate was 5.9% (1013/17 233). Moderate to very frequent use of ultrasound guidance varied by site: internal jugular vein (80%), subclavian vein (31%), and femoral vein (45%). Nearly all physicians (99%) who insert internal jugular CVCs daily use ultrasound guidance, whereas only 46% of physicians who insert subclavian CVCs daily use ultrasound guidance. Use of real-time ultrasound guidance varied by insertion site: internal jugular vein (73%), subclavian vein (28%), and femoral vein (42%). Most physicians (59%) reported not being comfortable with real-time needle tracking at the subclavian site. The most frequently reported barriers to use of ultrasound guidance were (1) limited availability of ultrasound equipment (28%), (2) perception of increased total procedure time (22%), and (3) concern for loss of landmark skills (13%). CONCLUSIONS Most intensivists routinely use ultrasound guidance to insert internal jugular CVCs but not subclavian CVCs. The most commonly reported barrier to ultrasound use was limited access to an ultrasound machine.

A non-human primate model of severe pneumococcal pneumonia

Rationale Streptococcus pneumoniae is the leading cause of community-acquired pneumonia and infectious death in adults worldwide. A non-human primate model is needed to study the molecular mechanisms that underlie the development of severe pneumonia, identify diagnostic tools, explore potential therapeutic targets, and test clinical interventions during pneumococcal pneumonia. Objective To develop a non-human primate model of pneumococcal pneumonia. Methods Seven adult baboons (Papio cynocephalus) were surgically tethered to a continuous monitoring system that recorded heart rate, temperature, and electrocardiography. Animals were inoculated with 109 colony-forming units of S. pneumoniae using bronchoscopy. Three baboons were rescued with intravenous ampicillin therapy. Pneumonia was diagnosed using lung ultrasonography and ex vivo confirmation by histopathology and immunodetection of pneumococcal capsule. Organ failure, using serum biomarkers and quantification of bacteremia, was assessed daily. Results Challenged animals developed signs and symptoms of pneumonia 4 days after infection. Infection was characterized by the presence of cough, tachypnea, dyspnea, tachycardia and fever. All animals developed leukocytosis and bacteremia 24 hours after infection. A severe inflammatory reaction was detected by elevation of serum cytokines, including Interleukin (IL)1Ra, IL-6, and IL-8, after infection. Lung ultrasonography precisely detected the lobes with pneumonia that were later confirmed by pathological analysis. Lung pathology positively correlated with disease severity. Antimicrobial therapy rapidly reversed symptomology and reduced serum cytokines. Conclusions We have developed a novel animal model for severe pneumococcal pneumonia that mimics the clinical presentation, inflammatory response, and infection kinetics seen in humans. This is a novel model to test vaccines and treatments, measure biomarkers to diagnose pneumonia, and predict outcomes.

Diagnostic point-of-care ultrasound for hospitalists

We review the literature on diagnostic point-of-care ultrasound applications most relevant to hospital medicine and highlight gaps in the evidence base. Diagnostic point-of-care applications most relevant to hospitalists include cardiac ultrasound for left ventricular systolic function, pericardial effusion, and severe mitral regurgitation; lung ultrasound for pneumonia, pleural effusion, pneumothorax, and pulmonary edema; abdominal ultrasound for ascites, aortic aneurysm, and hydronephrosis; and venous ultrasound for central venous volume assessment and lower extremity deep venous thrombosis. Hospitalists and other frontline providers, as well as physician trainees at various levels of training, have moderate to excellent diagnostic accuracy after brief training programs for most of these applications. Despite the evidence supporting the diagnostic accuracy of point-of-care ultrasound, experimental evidence supporting its clinical use by hospitalists is limited to cardiac ultrasound.

Ultrasound guidance for lumbar puncture

Purpose of review:To review the literature and describe techniques to use ultrasound to guide performance of lumbar puncture (LP). Recent findings:Ultrasound evaluation of the lumbar spine has been shown in randomized trials to improve LP success rates while reducing the number of attempts and the number of traumatic taps. Summary:Ultrasound mapping of the lumbar spine reveals anatomical information that is not obtainable by physical examination, including depth of the ligamentum flavum, width of the interspinous spaces, and spinal bone abnormalities, including scoliosis. Using static ultrasound, the lumbar spine anatomy is visualized in transverse and longitudinal planes and the needle insertion site is marked. Using real-time ultrasound guidance, the needle tip is tracked in a paramedian plane as it traverses toward the ligamentum flavum. Future research should focus on efficient methods to train providers, cost-effectiveness of ultrasound-guided LP, and the role of new needle-tracking technologies to facilitate the procedure.

Admission inferior vena cava measurements are associated with mortality after hospitalization for acute decompensated heart failure.

BACKGROUND Prognostication of patients hospitalized with acute decompensated heart failure (ADHF) is important to patients, providers, and healthcare systems. Few bedside tools exist to prognosticate patients hospitalized with ADHF. OBJECTIVE The objective of this study was to assess the relationship between inferior vena cava (IVC) diameter and postdischarge mortality in patients hospitalized with ADHF. DESIGN Prospective observational study. SETTING A 247-bed urban teaching hospital in Spain PATIENTS: Ninety-seven patients hospitalized with ADHF. INTERVENTION None. MEASUREMENTS The IVC diameter and collapsibility were measured by a hospitalist at the time of admission and discharge. Primary outcome was 90-day all-cause mortality. Secondary outcomes were readmission rates at 90 and 180 days, and 180-day all-cause mortality. Patients were followed for 180 days. RESULTS Data from 80 patients were analyzed. From admission to discharge, a significant improvement in IVC maximum (IVCmax ) diameter (2.12 vs 1.87 cm; P < 0.001) and IVC collapsibility (25.7% vs 33.1%; P < 0.001) was seen in the total study cohort. During the 90-day follow-up period, 11 patients (13.7%) died. An admission IVCmax diameter ≥1.9 cm was associated with a higher mortality rate at 90 days (25.4% vs 3.4%; P = 0.009) and 180 days (29.3% vs 3.4%; P = .003). In a multivariate Cox proportional hazards regression analysis, admission IVCmax diameter was an independent predictor of 90-day mortality (hazard ratio [HR]: 5.88; 95% confidence interval [CI]: 1.21-28.10; P = 0.025) and 90-day readmission (HR: 3.20; 95% CI: 1.24-8.21; P = 0.016). CONCLUSION In patients hospitalized with acute decompensated heart failure, a dilated IVC by bedside ultrasound at the time of admission is associated with a higher 90-day mortality after hospitalization. Journal of Hospital Medicine 2016;11:778-784.