[Executive functions in patients with obstructive sleep apnea: exploring the prefrontal model]. / Funciones ejecutivas en pacientes con apnea obstructiva del sueño: explorando el modelo prefrontal.

INTRODUCTION: According to the prefrontal model, individuals with obstructive sleep apnea (OSA) manifest behaviours mimicking dysexecutive syndrome as a result of blood gas abnormalities and sleep fragmentation. OBJECTIVE: To compare executive functions in OSA patients with normative values and explore their relationship with blood gas abnormalities and sleep fragmentation. PATIENTS AND METHODS: Patients were recruited from the wider community and from a tertiary care hospital. The score obtained in the neuropsychological assessment was compared with Student's t-test for a sample. A multiple linear regression analysis was subsequently estimated, using polysomnographic parameters of hypercapnia, hypoxemia and sleep fragmentation as the predictor variables, and the executive function score as the variable to be predicted. RESULTS: Although the neuropsychological assessment performance of 26% of this sample was classified as executive impairment, indicators of sleep fragmentation and gas abnormalities failed to predict the performance of executive functions. CONCLUSION: A proportion of the patients with OSA presented performance similar to a dysexecutive syndrome; however, the factors underlying and fostering this type of cognitive manifestation remain unclear. Early treatment for this public health problem could be the best tool available for improving quality of life and preventing health risks.

TITLE: Funciones ejecutivas en pacientes con apnea obstructiva del sueño: explorando el modelo prefrontal.Introducción. El modelo prefrontal propone que los individuos con apnea obstructiva del sueño (AOS) manifiestan conductas similares a un síndrome disejecutivo como resultado de las alteraciones de gases en la sangre y la fragmentación del sueño. Objetivo. Comparar las funciones ejecutivas en pacientes con AOS con valores normativos y explorar su relación con las alteraciones de gases en la sangre y la fragmentación del sueño. Pacientes y métodos. Se reclutó a pacientes de la comunidad general y de un hospital de tercer nivel. La puntuación obtenida en la evaluación neuropsicológica se contrastó con la t de Student para una muestra. Posteriormente, se estimó un análisis de regresión lineal múltiple mediante parámetros polisomnográficos de hipercapnia, hipoxemia y fragmentación del sueño como variables predictoras, y la puntuación de funciones ejecutivas como variable que se debe predecir. Resultados. Pese a que el desempeño en la evaluación neuropsicológica del 26% de esta muestra se clasificó como alteración ejecutiva, los indicadores de fragmentación del sueño y alteraciones de gases no predijeron el desempeño ejecutivo. Conclusión. Una fracción de los pacientes con AOS mostró un desempeño similar a un síndrome disejecutivo; no obstante, permanecen indefinidos los factores que subyacen y favorecen este tipo de manifestaciones cognitivas. La atención temprana de este problema de salud pública podría ser la mejor herramienta disponible en aras de mejorar la calidad de vida y prevenir riesgos a la salud.

Abnormal pulmonary function tests predict the development of radiation-induced pneumonitis in advanced non-small cell lung Cancer.

BACKGROUND: Radiation pneumonitis (RP) is a frequent complication of concurrent chemoradiotherapy (CCRT) and is associated with severe symptoms that decrease quality of life and might result in pulmonary fibrosis or death. The aim of this study is to identify whether pulmonary function test (PFT) abnormalities may predict RP in non-small cell lung cancer (NSCLC) patients. METHODS: A prospective multi-institutional study was conducted with locally advanced and oligometastatic NSCLC patients. All participants were evaluated at baseline, end of CCRT, week 6, 12, 24, and 48 post-CCRT. They completed forced spirometry with a bronchodilator, body plethysmography, impulse oscillometry, carbon monoxide diffusing capacity (DLCO), molar mass of CO2, six-minute walk test and exhaled fraction of nitric oxide (FeNO). Radiation pneumonitis was assessed with RTOG and CTCAE. The protocol was registered in www.clinicaltrials.gov (NCT01580579), registered April 19, 2012. RESULTS: Fifty-two patients were enrolled; 37 completed one-year follow-up. RP ≥ Grade 2 was present in 11/37 (29%) for RTOG and 15/37 (40%) for CTCAE. Factors associated with RP were age over 60 years and hypofractionated dose. PFT abnormalities at baseline that correlated with the development of RP included lower forced expiratory volume in one second after bronchodilator (p = 0.02), DLCO (p = 0.02) and FeNO (p = 0.04). All PFT results decreased after CCRT and did not return to basal values at follow-up. CONCLUSIONS: FEV1, DLCO and FeNO prior to CCRT predict the development of RP in NSCLC. This study suggests that all patients under CCRT should be assessed by PFT to identify high-risk patients for close follow-up and early treatment.

Functionality of CD4+ and CD8+ T cells from tonsillar tissue.

For many years, tonsillectomy has been used routinely in children to treat chronic or recurrent acute tonsillitis. Palatine tonsils are secondary lymphoid organs and the major barrier protecting the digestive and respiratory tracts from potential invasive microorganisms. They have been used as sources of lymphoid tissue; however, despite the hundreds of papers published on tonsillectomy, no studies addressing the functionality of the CD4(+) and CD8(+) T cells from chronically infected tonsils have yet been published. The aim of this study was to analyse the functionality of the CD4(+) and CD8(+) T cells with respect to tonsillar tissue. We used an affordable approach to measure the frequency of antigen-specific CD4(+) T cells, the direct ex-vivo cytotoxicity of CD8(+) T cells, memory T cell phenotype, cytokine profile and DC phenotype. Our results demonstrate that CD4(+) and CD8(+) T cells from tonsillar tissue are totally functional, as shown by their ability to produce cytokines, to degranulate and to differentiate into effector-memory T cells.

Frequency of adverse events and mortality in patients with pleural empyema in a public referral hospital in Mexico City.

SETTING: Adverse events (AEs) that occur during medical treatment are a public health problem. OBJECTIVE: 1) To measure the prevalence of AEs, 2) to characterize those that occur in patients diagnosed with empyema and 3) to analyze the mortality rate associated with the presence of empyema. DESIGN: Retrospective case series based on a review of files of patient diagnosed with empyema. RESULTS: A total of 347 files were assessed, reporting 96.6% of the total number of patients diagnosed with empyema in that period. There were 176 AEs reported for 150 of the patients. The frequency of at least one AE was 43%, with prolonged hospitalization being the most frequent condition. In these cases, 97% of the AEs were considered preventable. Intrahospital mortality was 4.8%, with age (HR for every 5 years 1.21, 95%CI 1.08-1.35, P < 0.001) and the presence of diabetes mellitus (HR 2.26, 95%CI 1.0-5.0, P = 0.04) being significant associated factors. CONCLUSION: There was a high frequency of AEs in patients with empyema, but most were considered preventable, especially the length of hospitalization, which could be reduced through timely surgery.

Comprehensive exercise training improves ventilatory muscle function and reduces dyspnea perception in patients with COPD.

BACKGROUND: Comprehensive exercise training (CET) is an efficient strategy to decrease dyspnea perception in chronic obstructive pulmonary disease (COPD) and may result in significant improvement in ventilatory muscles function. Our aim was to evaluate the effects of general exercise training on dyspnea perception and on respiratory muscles strength in COPD patients. METHODS: Consecutive COPD patients were enrolled to complete a CET programme. The patients underwent a routine that included a global warm up, upper and lower limbs endurance exercise as well as stretching and relaxation. Before and after the CET programme, patients completed maximal inspiratory (PImax) and expiratory (PEmax) pressures measurements, maximal incremental test, endurance test, and 6-min walk distance (6MWD). RESULTS: 71 patients (52 male). Mean age 67.6 +/- 8.6 years, FEV1 (%) 44.2 +/- 16.2 and Mahler dyspnea scale 6.4 +/- 1.8. The results before and after the exercise programme were: PImax 64.7 +/- 22.9 vs. 75.5 +/- 23.7 cmH2O (p=0.001), PEmax 110.8 +/- 28.1 vs. 120.4 +/- 28.1 cmH2O (p=0.004), 6MWD 510.6 +/- 90.3 vs. 528.2 +/- 99.7 metres (p=0.88), time of incremental test 672 +/- 135 vs. 856 +/- 226 sec (p<0.0001). Compared with the pre exercise programme, we observed a significant reduction on Borg dyspnea scale (6.1 +/- 2.8 to 3.6 +/- 2.3, p<0.0001) as well as a longer test time (504 +/- 218 to 1.038 +/- 841, p<0.0001) at the end of the endurance test after CET programme. Improvement of PImax correlated negatively with dyspnea perception at iso-time during the endurance test (r = -0.33, p=0.03). CONCLUSIONS: Our results confirm that CET is associated with significant improvement in PImax, PEmax and provide evidence demonstrating that CET reduces dyspnea perception in patients with COPD.

Preoperative continuous positive airway pressure compliance in children with obstructive sleep apnea syndrome: assessed by a simplified approach.

INTRODUCTION: The frequency of diagnoses of obstructive sleep apnea syndrome (OSAS) in children is increasing and more and more adenotonsillectomies (A&T) are being performed on severely ill children who have a higher perioperatory risk. The objective of the present study was to describe preoperative compliance in the use of continuous positive airway pressure (CPAP) in children with OSAS, when this treatment was prescribed as a means of preventing complications. PATIENTS AND METHODS: We describe data from children with severe OSAS caused by hypertrophy of the adenoids and tonsils, but with no craniofacial abnormalities. CPAP pressure was adjusted either during diurnal polysomnography with sleep deprivation or by self-adjusting devices. Follow-up was conducted through weekly interviews and the downloading of data recorded by the equipment. RESULTS: 48 children were included; 73% of them used a CPAP machine > or =3h per night, and 31% used it for > or =6h per night. The variables associated with good equipment compliance included higher BMI, higher pressure levels in the devices, and a higher number of episodes of apneas and hypopneas. Children who weighed > or =30kg used CPAP for > or =3h per night more often (OR 16, 95% CI 1.9-137). Compliance levels with fixed and self-adjusting CPAP were similar, and side effects in both cases were slight and limited to those caused by the pressure of the masks on patients' skin. One case of excessive bleeding was the only complication reported during A&T. CONCLUSIONS: The mean preoperative use of CPAP equipment by children with severe OSAS was 4.5+/-2.6h. Seventy-three percent of subjects used the equipment for >/=3h.

Effects of hyperinflation on the oxygen pulse as a marker of cardiac performance in COPD.

A decreased inspiratory capacity (IC)/total lung capacity (TLC) ratio is associated with dynamic hyperinflation and decreased exercise capacity. The present authors hypothesised that static (low IC/TLC) and dynamic hyperinflation impair cardiac function as assessed by oxygen pulse at rest and during cardiopulmonary exercise testing (CPET). Lung function, body mass index, hand grip strength and CPET parameters were measured (oxygen uptake (mL x kg(-1) x min(-1)) and oxygen pulse (mL x beat(-1))) in 87 chronic obstructive pulmonary disease (COPD) patients (American Thoracic Society/European Respiratory Society/Global Initiative for Chronic Obstructive Lung Disease stage 3-4) and 46 controls. The patients were divided into those with IC/TLC > 25% or < or = 25%. The IC/TLC ratio at rest and at peak exercise was associated significantly with oxygen pulse. Patients with IC/TLC < or = 25% (n = 45) had significantly lower exercise capacity, peak oxygen pulse, peak minus baseline oxygen pulse, peak IC, peak IC/TLC ratio and % change from baseline to peak IC/TLC ratio compared with patients with IC/TLC > 25% and controls. During CPET, the oxygen pulse was lower at iso-work in patients with IC/TLC < or = 25% than in those with IC/TLC > 25%. Resting hyperinflation (inspiratory capacity/total lung capacity) is associated with lower oxygen pulse, peak exercise inspiratory capacity/total lung capacity and exercise capacity in patients with severe chronic obstructive pulmonary disease. The present results support an interaction between hyperinflation and decreased cardiac function that may contribute to exercise limitation in these patients.

Characterization of a cytotoxic CD57+ T cell subset from patients with pulmonary tuberculosis.

We investigated the proportion, phenotype, and cytotoxicity of CD8+CD57+ and CD57- T cells in peripheral blood from 20 tuberculosis (TB)-patients and 20 healthy tuberculin skin test-positive donors. Our results showed an increase in CD8+CD57+ T cells from TB-patients as compared with those from age-matched healthy donors (p<0.0001). CD8+CD57+ T cells from TB-patients expressed CD69, perforin, granzyme-A, and a CD28-CD62L-CD161- phenotype without recognition for the alpha-galactosylceramide-CD1d complex. This cell subset also expressed TNF-alpha and IFN-gamma, under phorbol-myristate-acetate/ionomycin stimulation. Interestingly, the cytotoxicity against autologous monocytes was higher in CD57- cells from TB-patients and donors than their CD57+ counterparts, in the presence of Mycobacterium tuberculosis H37Rv culture filtrate. However, only CD8+CD57+ T cells from TB-patients exhibited spontaneous cytotoxicity against monocytes in the absence of antigen. Our results suggest that CD8+CD57+ T cells are a subset of effector cells that could be helpful to evaluate the cell-mediated immune response to M. tuberculosis.

Prevalence of oxygen desaturation and use of oxygen at home in adults at sea level and at moderate altitude.

The aim of this study was to determine the prevalence of oxygen desaturation in adults aged>or=40 yrs as altitude above sea level increases. A population-based, cross-sectional study with a multistage cluster sampling of 1,063 subjects from metropolitan Mexico City (Mexico; 2,240 m above sea level), 1,357 from Caracas (Venezuela; 950 m) and 943 from Montevideo (Uruguay; 35 m). The mean of six measurements of arterial oxygen saturation (SP,O2) was estimated using a pulse oximeter. Mean SP,O2 decreased with altitude. No subject from Montevideo had a mean SP,O288%. In conclusion, the prevalence of hypoxaemia was closely related to altitude. Priorities for oxygen prescription must be defined in moderate altitudes because it is unfeasible to provide it to all subjects fulfilling the criteria commonly used.