Alvaro Proaño

Dynamics of Cough Frequency in Adults Undergoing Treatment for Pulmonary Tuberculosis.

Summary This is the first research to evaluate cough frequency continuously over 24-hour periods and to characterize associations with mycobacterial load and treatment. This study provides novel information on the circadian cycle of cough frequency and risk factors for increased cough frequency.

Protocol for studying cough frequency in people with pulmonary tuberculosis

Introduction Cough is a key symptom of tuberculosis (TB) as well as the main cause of transmission. However, a recent literature review found that cough frequency (number of coughs per hour) in patients with TB has only been studied once, in 1969. The main aim of this study is to describe cough frequency patterns before and after the start of TB treatment and to determine baseline factors that affect cough frequency in these patients. Secondarily, we will evaluate the correlation between cough frequency and TB microbiological resolution. Methods This study will select participants with culture confirmed TB from 2 tertiary hospitals in Lima, Peru. We estimated that a sample size of 107 patients was sufficient to detect clinically significant changes in cough frequency. Participants will initially be evaluated through questionnaires, radiology, microscopic observation drug susceptibility broth TB-culture, auramine smear microscopy and cough recordings. This cohort will be followed for the initial 60 days of anti-TB treatment, and throughout the study several microbiological samples as well as 24 h recordings will be collected. We will describe the variability of cough episodes and determine its association with baseline laboratory parameters of pulmonary TB. In addition, we will analyse the reduction of cough frequency in predicting TB cure, adjusted for potential confounders. Ethics and dissemination Ethical approval has been obtained from the ethics committees at each participating hospital in Lima, Peru, Asociación Benéfica PRISMA in Lima, Peru, the Universidad Peruana Cayetano Heredia in Lima, Peru and Johns Hopkins University in Baltimore, USA. We aim to publish and disseminate our findings in peer-reviewed journals. We also expect to create and maintain an online repository for TB cough sounds as well as the statistical analysis employed.

The Latin America and the Caribbean search strategy proposal

Latin America and the Caribbean’s public health literature is not widely recognized. Science in this region has even been compared to a night sky with just a few specks of light. To make those lights as reachable as possible, we developed the Latin America and the Caribbean Search Strategy (LACSS). This is a new method to utilize our region’s health promotion results within MEDLINE/PubMed. In contrast to a typical MeSH query, LACSS retrieves up to six times more publication results regarding non-communicable diseases, neglected tropical diseases, injuries and other important public health relevant topics in the region. We believe that global health promotion will be improved in this region by improving its visibility, and this search strategy will contribute to this.

Computer automated algorithm to evaluate cavitary lesions in adults with pulmonary tuberculosis

The presence of a cavitary lesion is a radiographic hallmark of pulmonary tuberculosis (TB). The sizes of the cavitary lesion and its proximity to the bronchial tree have been associated with mycobacterial burden (1).

Z-Score: Fenton 2013. Ten-year update

We read with great interest the article by Lima et al. on the determination of extrauterine growth restriction (EUGR) in very low birth weight infants, as well as the effect several perinatal variables had on this outcome. They define EUGR as weight Z-score or head circumference Z-score less than or equal to -2. Also, they classify the newborns as adequate for gestational age (AGA) or small for gestational age (SGA) based on the birth weight Z-score. It is important to denote here that the calculated Z-scores were based on Fenton’s growth chart of 2003. In 2013, the Fenton 2003 Preterm Growth chart was updated by a rigorous meta-analysis which included 3,986,456 births from Germany, United States, Italy, Australia, Scotland, and Canada. By doing so, they updated the Z-scores for length, head circumference, and weight; these new Z-scores can be easily calculated using the online calculators at: http://www.ucalgary.ca/fenton/. We do not know whether the results of the study would have been the same if the Z-scores of the study had been based on the 2013 Fenton Preterm Growth Chart. However, it was impossible for Lima et al. to base their study on the updated Z-scores, since Fenton’s new growth chart was published a month after their study was submitted to the Jornal de Pediatria. We would like to know whether it would be possible to revise the study using the new and updated growth chart to see if the results are different. We must add that Fenton’s 2013 growth chart is the best reference we have until now. Nevertheless, we are looking forward to the new results of the INTERGROWTH-21

Linking Individual Natural History to Population Outcomes in Tuberculosis

Experimental models of tuberculosis are rarely interrogated for consistency with observed clinical outcomes at the population level. We developed a mathematical framework of tuberculosis to describe individual-level rates of disease progression and recovery that are consistent with reported clinical outcomes.

Cough Frequency During Treatment Associated With Baseline Cavitary Volume and Proximity to the Airway in Pulmonary TB

Background: Cough frequency, and its duration, is a biomarker that can be used in low‐resource settings without the need of laboratory culture and has been associated with transmission and treatment response. Radiologic characteristics associated with increased cough frequency may be important in understanding transmission. The relationship between cough frequency and cavitary lung disease has not been studied. Methods: We analyzed data in 41 adults who were HIV negative and had culture‐confirmed, drug‐susceptible pulmonary TB throughout treatment. Cough recordings were based on the Cayetano Cough Monitor, and sputum samples were evaluated using microscopic observation drug susceptibility broth culture; among culture‐positive samples, bacillary burden was assessed by means of time to positivity. CT scans were analyzed by a US‐board‐certified radiologist and a computer‐automated algorithm. The algorithm evaluated cavity volume and cavitary proximity to the airway. CT scans were obtained within 1 month of treatment initiation. We compared small cavities (≤ 7 mL) and large cavities (> 7 mL) and cavities located closer to (≤ 10 mm) and farther from (> 10 mm) the airway to cough frequency and cough cessation until treatment day 60. Results: Cough frequency during treatment was twofold higher in participants with large cavity volumes (rate ratio [RR], 1.98; P = .01) and cavities located closer to the airway (RR, 2.44; P = .001). Comparably, cough ceased three times faster in participants with smaller cavities (adjusted hazard ratio [HR], 2.89; P = .06) and those farther from the airway (adjusted HR, 3.61;, P = .02). Similar results were found for bacillary burden and culture conversion during treatment. Conclusions: Cough frequency during treatment is greater and lasts longer in patients with larger cavities, especially those closer to the airway.

Nutritional intake and weight z-scores in very low birth weight infants in Peru

OBJECTIVES To determine the actual nutritional intake of very low birth weight infants and their growth outcome during the first month of life. Additionally, we identified factors that account for a negative neonatal outcome in this population. METHODS A case-series study was conducted in a tertiary hospital in Lima, Peru between 2011 and 2012 and the data was obtained from medical records. No feeding protocol was used during this study. Daily fluids, energy and protein intakes were documented and weekly weight z-scores were calculated. A logistic regression analysis was used to identify factors for an adverse outcome, defined as neonatal mortality or extra-uterine growth restriction, during the first 28 days of life. RESULTS After applying selection criteria, 76 participants were included. The nutritional intakes were similar to standard values seen in the literature, but protein intakes were suboptimal in all of the four weeks. Birth weight z-score was associated with an adverse outcome (p=0.035). It was determined that having a birth weight z-score under -1.09 predicted a negative outcome with an area under the curve of 96.8% [93.5%, 100%] with a 95% confidence interval. CONCLUSION Protein intakes are widely deficient in the population of this study. Nevertheless, an adverse outcome during the neonatal period is more associated with a poor birth weight z-score than nutrition-related factors.

What medical students need: Virtual patients or real patients?

certainly been revolutionized. From a personal perspective, I look forward to reading formal research around the topic – the open book statistical assessment was certainly not a walk in the park. The format of the assessment required significant theoretical application. The book simply allowed for refreshment of factual knowledge. The assessment relied on candidates being able to interpret data provided and comment accordingly. For example, research data with confidence intervals, p values, odds ratios, Wald and degrees of freedom values featured heavily. In addition, candidates were asked to comment on assumptions made, potential confounding variables and additional univariate and multivariate tests of choice, as well as construct potential tables for data we would like to collect for specific research questions. In medical practice, postgraduate training often relies on referring to current literature when managing a patient appropriately, particularly evidence-based specialty guidelines. Of course, it is important for candidates to learn the theory; but I wonder whether the use of open book assessments could potentially be a good thing. If constructed properly, they could provide a more suitable platform of theory application as opposed to simple recall.

Cartas ao editorZ‐Score: Fenton 2013. Ten‐year updateEscore Z: Fenton 2013. Atualização de dez anos☆☆☆

Lemos com grande interesse o artigo de Lima et al.1 sobre a determinação de restrição do crescimento extrauterino (RCEU) em neonatos com muito baixo peso ao nascer, bem como o efeito apresentado de diversas variáveis perinatais sobre esse resultado. Eles definiram RCEU como escore z para peso ou escore z para perímetro cefálico inferior ou igual a --2. Além disso, classificaram os recém-nascidos como adequados para a idade gestacional (AIG) ou pequenos para a idade gestacional (PIG) com base no escore z para peso ao nascer. É importante identificar que os escores z calculados tiveram como base o gráfico de crescimento de Fenton, 2003.2,3 Em 2013, o gráfico de Crescimento Prematuro de Fenton, 2003 foi atualizado por uma meta-análise rigorosa que incluiu 3.986.456 nascimentos da Alemanha, Estados Unidos, Itália, Austrália, Escócia e Canadá.4,5 Ao fazê-lo, eles atualizaram os escores z para comprimento, perímetro cefálico e peso; esses novos escores z podem ser facilmente calculados pelas calculadoras on-line, em: http://www.ucalgary.ca/fenton/. Não sabemos se os resultados do estudo teriam sido os mesmos se os escores z adotados tivessem tido como base o Gráfico de Crescimento Prematuro de Fenton, 2003. Contudo, foi impossível para Lima e seus colaboradores basearem seu estudo nos escores z atualizados, pois o novo gráfico de crescimento de Fenton foi publicado um mês após este ter sido enviado ao Jornal de Pediatria. Gostaríamos de saber da possibilidade de se fazer uma revisão do mesmo