Effect of continuous positive airway pressure in very elderly with moderate-to-severe obstructive sleep apnea pooled results from two multicenter randomized controlled trials.

STUDY OBJECTIVE: There is very limited information about the effect of continuous positive airway pressure (CPAP) in the very elderly. Here we aimed to analysed the effect of CPAP on a clinical cohort of patients with obstructive sleep apnea (OSA) ≥80 years old. METHODS: Post-hoc pooled analysis of two open-label, multicenter clinical trials aimed to determine the effect of CPAP in a consecutive clinical cohort of elderly (≥70 years old) with moderate-to-severe OSA (apnea-hipopnea index ≥15 events/hour) randomized to receive CPAP or no CPAP for three months. Those consecutive patients ≥80 years old were included in the study. The primary endpoint was the change in Epworth Sleepiness scale (ESS). Secondary outcomes included sleep-related symptoms, quality of life, neurocognitive and mood status as well as office blood pressure measurements. RESULTS: From the initial 369 randomized individuals with ≥70 years, 97 (26.3%) with ≥80 years old were included (47 in the CPAP group and 50 in the no-CPAP group). The mean (SD) age was 81.5 (2.4) years. Average use of CPAP was 4.3 (2.6) hours/night (53% with good adherence) Patients in the CPAP group significantly improved snoring and witnessed apneas as well as AHI (from 41.9 to 4.9 events/hour). However no clinical improvements were seen in ESS (-1.2 points, 95%CI, 0.2 to -2.6), any domain of QSQ, any neurocognitive test, OSA-related symptoms, depression/anxiety or blood pressure levels. CONCLUSIONS: The present study does not support the use of CPAP in very elderly patients with moderate-to-severe OSA.

Classification of glucose records from patients at diabetes risk using a combined permutation entropy algorithm.

BACKGROUND AND OBJECTIVES: The adoption in clinical practice of electronic portable blood or interstitial glucose monitors has enabled the collection, storage, and sharing of massive amounts of glucose level readings. This availability of data opened the door to the application of a multitude of mathematical methods to extract clinical information not discernible with conventional visual inspection. The objective of this study is to assess the capability of Permutation Entropy (PE) to find differences between glucose records of healthy and potentially diabetic subjects. METHODS: PE is a mathematical method based on the relative frequency analysis of ordinal patterns in time series that has gained a lot of attention in the last years due to its simplicity, robustness, and performance. We study in this paper the applicability of this method to glucose records of subjects at risk of diabetes in order to assess the predictability value of this metric in this context. RESULTS: PE, along with some of its derivatives, was able to find significant differences between diabetic and non-diabetic patients from records acquired up to 3 years before the diagnosis. The quantitative results for PE were 3.5878 ±â€¯0.3916 for the nondiabetic class, and 3.1564 ±â€¯0.4166 for the diabetic class. With a classification accuracy higher than 70%, and by means of a Cox regression model, PE demonstrated that it is a very promising candidate as a risk stratification tool for continuous glucose monitoring. CONCLUSION: PE can be considered as a prospective tool for the early diagnosis of the glucoregulatory system.

Sleep biosignature of Type 2 diabetes: a case-control study.

AIM: To determine whether or not the sleep disturbances associated with Type 2 diabetes affect the structure of sleep. METHODS: We designed a case-control study in 76 patients with Type 2 diabetes and 76 control subjects without Type 2 diabetes, matched by age, gender, BMI and waist and neck circumferences. A subgroup of 32 patients with Type 2 diabetes was also matched with 64 control subjects without Type 2 diabetes according to apnoea-hypopnoea index score. Examination included an overnight full polysomnography. RESULTS: No differences in the percentage of time spent in either rapid eye movement or non-rapid eye movement sleep were observed between groups; however, patients with Type 2 diabetes had more microarousal events during sleep than control subjects [41.4 (total range 4.0-104.4) vs 20.7 (total range 1.3-94.5) events/h; P < 0.001]. These differences were mainly observed during the non-rapid eye movement sleep [7.4 (total range 0-107.2) vs 0.2 (total range 0-65.2) events/h; P < 0.001]. In addition, sleep variables related to oxygen saturation measures, such as the percentage of time spent with oxygen saturation ≤90%, were significantly greater during the rapid eye movement sleep in patients with Type 2 diabetes [20.3 (total range 0-99.2) vs. 10.5 (total range 0-94.0)%; P = 0.047]. This pattern was maintained in the subgroup of patients matched by apnoea-hypopnaea index. Finally, stepwise regression analyses showed that apnoea-hypopnoea index, the presence of Type 2 diabetes and fasting plasma glucose value were independently associated with the number of microarousals (R2 =0.667). CONCLUSIONS: Type 2 diabetes is associated with an altered sleep structure, with different effects according to rapid eye movement (increase in nocturnal hypoxia) or non-rapid eye movement (increase in sleep fragmentation) sleep.

Asthma outcomes improve with continuous positive airway pressure for obstructive sleep apnea.

BACKGROUND: Continuous positive airway pressure (CPAP) in asthma patients with concomitant obstructive sleep apnea syndrome (OSAS) seems to have a favorable impact on asthma, but data are inconsistent due to methodological limitations of previous studies. METHODS: Prospective, multicenter study. We examined asthma outcomes after 6 months of CPAP in 99 adult asthma patients (mean age 57 years) with OSAS (respiratory disturbance index ≥20). Asthma control and quality of life were assessed with the Asthma Control Questionnaire (ACQ) and the Mini Asthma Quality of Life Questionnaire (MiniAQLQ), respectively. Data were analyzed by intention-to-treat basis. RESULTS: The mean ± SD score of the ACQ decreased from 1.39 ± 0.91 at baseline to 1.0 ± 0.78 at 6 months (P = 0.003), the percentage of patients with uncontrolled asthma from 41.4% to 17.2% (P = 0.006), and the percentage of patients with asthma attacks in the 6 months before and after treatment from 35.4% to 17.2% (P = 0.015). The score of the mAQLQ increased from 5.12 ± 1.38 to 5.63 ± 1.17 (P = 0.009). There were also significant improvements in symptoms of gastroesophageal reflux and rhinitis, bronchial reversibility, and exhaled nitric oxide values (all P < 0.05). No significant changes were observed in drug therapy for asthma or their comorbidities nor in the patients' weight. CONCLUSIONS: Asthma control (both actual and future risk), quality of life, and lung function improved after starting continuous positive airway pressure in asthmatics with moderate to severe obstructive sleep apnea syndrome.

FDG-PET parameters predicting mediastinal malignancy in lung cancer.

BACKGROUND: Staging of mediastinal lymph nodes in non-small cell lung cancer (NSCLC) is mandatory. The maximum Standard Uptake Value (SUVmax) obtained using F-18 fluorodeoxyglucose positron emission tomography (FDG-PET) is the best non-invasive technique available for this evaluation, but its performance varies from center to center. The aim of the present study was to identify FDG-PET predictors of mediastinal malignancy that are able to minimize intercenter variability and improve the selection of subsequent staging procedures. METHOD: A multicenter study of NSCLC patients staged through FDG-PET and endobronchial ultrasonography with needle aspiration (EBUS-NA) was performed using therapeutic surgery with systematic nodal dissection as gold standard. Intercenter variability and predictive power for mediastinal malignancy of different FDG-PET measures were assessed, as well as the role of these measures for selecting additional staging procedures. RESULTS: One hundred and twenty-one NSCLC patients, of whom 94 (72%) had ≥1 hypermetabolic spots in the mediastinum, were included in the study. Mean SUVmax of the primary tumor was 12.3 (SD 6.3), and median SUVmax of the highest hypermetabolic spots in the mediastinum was 3.9 (IQR 2.4-7). Variability of FDG-PET measures between hospitals was statistically significant (p = 0.016 and p < 0.001 respectively), but lost significance when SUVmax in the mediastinum was expressed as a ratio or a subtraction from the primary tumor (SUVmax mediastinum/tumor, p = 0.083; and SUVmax mediastinum - tumor, p = 0.428 respectively). SUVmax mediastinum/tumor showed higher accuracy in the ROC analysis (AUC 0.77 CI 0.68-0.85, p < 0.001), and showed predictive power for mediastinal malignancy when using a 0.4 cutoff (OR 6.62, 95%CI 2.98-14.69). Sensitivities and negative predictive values of clinical staging through EBUS-NA attained values ranging between 57% and 92% after FDG-PET, which improved with additional techniques when the tumor had a diameter >3 cm and/or a SUVmax mediastinum/tumor ratio >0.4. CONCLUSION: The SUVmax mediastinum/tumor ratio is a good predictor of regional tumor extension in NSCLC. This measure is not influenced by intercenter variability and has an accuracy of over 70% for the identification of malignancy when using a 0.4 cutoff.

La mejoría del pronóstico cardiovascular de la diabetes mellitus tipo 2 ¿ es una realidad? / Improvement in cardiovascular prognosis of type 2 diabetes mellitus, is it a reality?

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Modification over time of pulse wave velocity parallel to changes in aortic BP, as well as in 24-h ambulatory brachial BP.

Arterial stiffness as assessed by carotid-femoral pulse wave velocity (cfPWV) is a marker of preclinical organ damage and a predictor of cardiovascular outcomes, independently of blood pressure (BP). However, limited evidence exists on the association between long-term variation (Δ) on aortic BP (aoBP) and ΔcfPWV. We aimed to evaluate the relationship of ΔBP with ΔcfPWV over time, as assessed by office and 24-h ambulatory peripheral BP, and aoBP. AoBP and cfPWV were evaluated in 209 hypertensive patients with either diabetes or metabolic syndrome by applanation tonometry (Sphygmocor) at baseline(b) and at 12 months of follow-up(fu). Peripheral BP was also determined by using validated oscillometric devices (office(o)-BP) and on an outpatient basis by using a validated (Spacelabs-90207) device (24-h ambulatory BP). ΔcfPWV over time was calculated as follows: ΔcfPWV=[(cfPWVfu-cfPWVb)/cfPWVb] × 100. ΔBP over time resulted from the same formula applied to BP values obtained with the three different measurement techniques. Correlations (Spearman 'Rho') between ΔBP and ΔcfPWV were calculated. Mean age was 62 years, 39% were female and 80% had type 2 diabetes. Baseline office brachial BP (mm Hg) was 143±20/82±12. Follow-up (12 months later) office brachial BP (mm Hg) was 136±20/79±12. ΔcfPWV correlated with ΔoSBP (Rho=0.212; P=0.002), Δ24-h SBP (Rho=0.254; P<0.001), Δdaytime SBP (Rho=0.232; P=0.001), Δnighttime SBP (Rho=0.320; P<0.001) and ΔaoSBP (Rho=0.320; P<0.001). A multiple linear regression analysis included the following independent variables: ΔoSBP, Δ24-h SBP, Δdaytime SBP, Δnighttime SBP and ΔaoSBP. ΔcfPWV was independently associated with Δ24-h SBP (ß-coefficient=0.195; P=0.012) and ΔaoSBP (ß-coefficient= 0.185; P=0.018). We conclude that changes in both 24-h SBP and aoSBP more accurately reflect changes in arterial stiffness than do office BP measurements.

[Characteristics of deep sedation in gastrointestinal endoscopic procedures performed by intensivists]. / Características de la sedación profunda en procesos endoscópicos gastrointestinales, realizada por médicos intensivistas.

OBJECTIVE: To determine tolerance, pain intensity, percentage of tests completed successfully and complications of deep sedation controlled by intensivists during gastrointestinal endoscopic procedures. DESIGN: A one-year, prospective observational study was carried out. SETTING: Department of Intensive Care intervention in the Endoscopy Unit of Hospital Universitario del Tajo (Spain). PATIENTS: Subjects over 15 years of age subjected to endoscopic procedures under deep sedation. RESULTS: A total of 868 patients were sedated during the study period, with the conduction of 1010 endoscopic procedures. The degree of tolerance was considered adequate («Very good¼/«Good¼) in 96.9% of the patients (95%CI: 95.7-98.1%), with a median score of 0 on the pain visual analog scale. A total of 988 endoscopic procedures were successfully completed (97.8%; 95%CI: 96.9-98.8%): 675 colonoscopies (97.1%) and 305 endoscopies (99.7%). Complications were recorded in 106 patients (12.2%; 95%CI: 10.0-14.5%). The most frequent being desaturation (6.1%), rhythm disturbances (5.1%) and hypotension (2.4%). CONCLUSION: Gastrointestinal endoscopic procedures under sedation controlled by intensivists are well tolerated and satisfactory for the patient, and are successfully completed in a very large percentage of cases. The procedures are associated with frequent minor complications that are resolved successfully.

Características de la sedación profunda en procesos endoscópicos gastrointestinales, realizada por médicos intensivistas / Characteristics of deep sedation in gastrointestinal endoscopic procedures performed by intensivists

OBJETIVO: Conocer la tolerancia, la intensidad del dolor, el porcentaje de pruebas completadas con éxito y las complicaciones de la sedación profunda, controlada por médicos intensivistas, para realizar procedimientos endoscópicos gastrointestinales. DISEÑO: Estudio observacional prospectivo durante un periodo de un año. Ámbito: Realizado por el Servicio de Medicina Intensiva en la Unidad de Endoscopias del Hospital Universitario del Tajo. PACIENTES: Mayores de 15 años a los que se realizó algún procedimiento endoscópico bajo sedación profunda. RESULTADOS: Durante el periodo de estudio fueron sedados 868 pacientes. Se les realizaron 1.010 procedimientos endoscópicos. El grado de tolerancia se consideró adecuado («Muy Bueno»/«Bueno») en el 96,9% (IC 95%: 95,7-98,1%) de los pacientes, con una mediana de dolor de 0 en la escala visual analógica. Un total de 988 procedimientos endoscópicos (97,8%; IC 95%: 96,9-98,8%) fueron completados con éxito, 675 colonoscopias (97,1%) y 305 gastroscopias (99,7%). Presentaron complicaciones 106 pacientes (12,2%; IC 95%: 10,0-14,5%). Las más frecuentes fueron la desaturación (6,1%), las alteraciones del ritmo (5,1%) y la hipotensión (2,4%). CONCLUSIÓN: La realización de procesos endoscópicos gastrointestinales bajo sedación profunda controlada por médicos intensivistas es bien tolerada, satisfactoria para el paciente y con un excelente porcentaje de pruebas completadas. Esta intervención se acompaña de frecuentes complicaciones, siendo todas de orden menor y resueltas con éxito

OBJECTIVE: To determine tolerance, pain intensity, percentage of tests completed successfully and complications of deep sedation controlled by intensivists during gastrointestinal endoscopic procedures. DESIGN: A one-year, prospective observational study was carried out. SETTING: Department of Intensive Care intervention in the Endoscopy Unit of Hospital Universitario del Tajo (Spain). PATIENTS: Subjects over 15 years of age subjected to endoscopic procedures under deep sedation. RESULTS: A total of 868 patients were sedated during the study period, with the conduction of 1010 endoscopic procedures. The degree of tolerance was considered adequate («Very good»/«Good») in 96.9% of the patients (95% CI: 95.7-98.1%), with a median score of 0 on the pain visual analog scale. A total of 988 endoscopic procedures were successfully completed (97.8%; 95% CI: 96.9-98.8%): 675 colonoscopies (97.1%) and 305 endoscopies (99.7%). Complications were recorded in 106 patients (12.2%; 95% CI: 10.0-14.5%). The most frequent being desaturation (6.1%), rhythm disturbances (5.1%) and hypotension (2.4%). CONCLUSION: Gastrointestinal endoscopic procedures under sedation controlled by intensivists are well tolerated and satisfactory for the patient, and are successfully completed in a very large percentage of cases. The procedures are associated with frequent minor complications that are resolved successfully

Factores y causas de mal control y estrategias de corresponsabilidad médico-paciente en el control de la hipertensión. Resultados de los estudios COROPINA y COREVALUA del programa CORRESPONDE / Factors and causes of poor control and strategies of physician-patient co-responsibility in the control of hypertension. Results of the COROPINA and COREVALUA studies of the CORRESPONDE program

Fundamento y objetivos. Los estudios COROPINA y COREVALUA forman parte del programa CORRESPONDE, que consiste en una intervención asistencial centrada en fortalecer la corresponsabilidad médico-paciente en el control de los factores de riesgo cardiovascular. Por su parte, los objetivos principales de COROPINA y COREVALUA son identificar médicos candidatos para participar en la intervención y conocer los principales factores relacionados con el mal control de la hipertensión arterial, así como las medidas de mayor impacto potencial para mejorar el control de la enfermedad. Material y métodos. COROPINA es una investigación prospectiva basada en el método Delphi que involucra a 1.169 médicos que ejercen en el Servicio Nacional de Salud español. COREVALUA es un sondeo de opinión realizado mediante un cuestionario asistido por vídeo dirigido a 1.402 participantes de perfil similar. Resultados. Ambos estudios coinciden en que la falta de conciencia de la propia enfermedad y el deterioro personal según condiciones sicofísicas de los pacientes son los dos factores que más dificultan el control de la hipertensión arterial. Entre las causas del mal control se destaca el tabaquismo, el sobrepeso, el exceso de fármacos concomitantes y la escasa duración de las consultas. Y las medidas para el control de la hipertensión arterial con mayor impacto potencial que se priorizan son aumentar los recursos asistenciales, concienciar al paciente del cumplimiento terapéutico y simplificar los planes terapéuticos. Conclusión. El orden de importancia relativa otorgada tanto a factores y causas de mal control como a estrategias para mejorar el grado de control de la hipertensión arterial son muy parecidas en ambos estudios, y a su vez consistentes con los resultados de trabajos precedentes

Background and objectives. The COROPINA and COREVALUA studies form a part of the CORRESPONDE program. This consists of a healthcare intervention that is geared toward strengthening joint doctor-patient responsibility in the control of cardiovascular risk factors. On their part, the main goals of COROPINA and COREVALUA are to identify medical candidates to participate in the intervention and to discover the main factors related to poor hypertension control, as well as measures with a higher potential impact on improving control of the disease. Material and methods. COROPINA is a prospective research endeavor based on the Delphi method involving 1,169 practicing physicians in the Spanish National Health Service. COREVALUA is an opinion poll consisting of a video-assisted questionnaire, targeting 1,402 participants with similar profiles. Results. Both studies coincide in the fact that the lack of awareness of the illness itself and personal deterioration depending on the patients' psychophysical conditions are the two factors that most complicate the control of hypertension. Foremost among the causes of poor control are smoking, overweight, an excess of concomitant drugs, and the short duration of consultations. Moreover, the hypertension control measures with the greatest potential impact which are prioritized include increasing healthcare resources, raising patient awareness with regard to therapeutic compliance, and simplifying therapeutic plans. Conclusion. The relative order of importance given to factors and causes of poor control as well as to strategies for improving the degree of control of hypertension is very similar in both studies, and is in turn consistent with the results of preceding studies

[The relationship between lung function and health-related quality of life in patients with generalized myasthenia gravis]. / Relación entre función pulmonar y calidad de vida relacionada con la salud en la miastenia gravis generalizada.

OBJECTIVE: To study lung function abnormalities and health-related quality of life (HRQL) in a group of patients diagnosed with generalized myasthenia gravis, and to analyze the relationship between these 2 sets of variables. PATIENTS AND METHODS: In a prospective study of 20 patients diagnosed with generalized myasthenia gravis, the following parameters were measured: spirometry, static lung volumes, breathing pattern, maximal respiratory pressures, and maximum voluntary ventilation. HRQL was assessed using the 36-item short form general health questionnaire (SF-36). RESULTS: The mean (SD) age of the patients was 64 (11) years. Patients were classified into 2 groups depending on whether they had IIa (12 patients) or IIb (8 patients) type disease. A small decrease in total lung capacity (86%) and slight reductions in maximal inspiratory pressure (88%) and maximum voluntary ventilation (63% in group IIb) were observed. The HRQL domains most affected were those related to physical activity and self-perceived health status in all groups, although women were more affected. The scores relating to vitality and physical activity were found to be significantly associated with forced vital capacity and lung volumes. Tidal volume was associated with maximal inspiratory and expiratory pressures, inspiratory capacity, and maximum voluntary ventilation. The respiratory rate to tidal volume ratio was inversely associated with the first three of these variables. CONCLUSIONS: A very slight restrictive pattern and a reduction in inspiratory muscle strength were observed. The HRQL domains most affected were those related to physical activity and the patients' self-perceived health status. The weakness of the respiratory muscles contributes to the abnormalities observed in lung function and to the deterioration of health-related quality of life.

Relación entre función pulmonar y calidad de vida relacionada con la salud en la miastenia gravis generalizada / The relationship between lung function and health-related quality of life in patients with generalized myasthenia gravis

Objetivo: Estudiar las alteraciones de la función pulmonar y de la calidad de vida relacionada con la salud (CVRS), así como las relaciones entre ambas áreas, en un grupo de pacientes diagnosticados de miastenia gravis generalizada. Pacientes y métodos: Se ha realizado un estudio prospectivo en 20 pacientes diagnosticados de miastenia gravis generalizada. Se evaluaron la espirometría, los volúmenes pulmonares estáticos, el patrón respiratorio, las presiones respiratorias máximas y la ventilación voluntaria máxima. La CVRS se valoró con el cuestionario general de salud SF-36. Resultados: La edad media (± desviación estándar) de los pacientes fue de 64 ± 11 años. Se clasificaron en IIa (12 pacientes) y IIb (8 pacientes). Se observaron una leve disminución de la capacidad pulmonar total (86%) y una ligera reducción de la presión inspiratoria máxima (88%) y de la ventilación voluntaria máxima (un 63% en el grupo IIb). Los dominios más afectados de la CVRS fueron los relacionados con la actividad física y la percepción general de la salud en todos los grupos, pero con mayor intensidad en el sexo femenino. Se observaron relaciones estadísticamente significativas entre las áreas de vitalidad y actividad física, la capacidad vital forzada y los volúmenes pulmonares. También se encontraron relaciones entre la presión inspiratoria máxima, la presión espiratoria máxima, la ventilación voluntaria máxima, la capacidad inspiratoria con volumen circulante y el índice volumen circulante. Conclusiones: Se observaron un patrón restrictivo muy ligero y reducción de la fuerza muscular inspiratoria. Los ámbitos de la CVRS más afectados fueron los relacionados con la actividad física y la percepción general de la salud. La afectación muscular respiratoria contribuye a una alteración en las variables de la función pulmonar y al deterioro de la calidad de vida relacionada con la salud

Objective: To study lung function abnormalities and health-related quality of life (HRQL) in a group of patients diagnosed with generalized myasthenia gravis, and to analyze the relationship between these 2 sets of variables. Patients and methods: In a prospective study of 20 patients diagnosed with generalized myasthenia gravis, the following parameters were measured: spirometry, static lung volumes, breathing pattern, maximal respiratory pressures, and maximum voluntary ventilation. HRQL was assessed using the 36-item short form general health questionnaire (SF-36). Results: The mean (SD) age of the patients was 64 (11) years. Patients were classified into 2 groups depending on whether they had IIa (12 patients) or IIb (8 patients) type disease. A small decrease in total lung capacity (86%) and slight reductions in maximal inspiratory pressure (88%) and maximum voluntary ventilation (63% in group IIb) were observed. The HRQL domains most affected were those related to physical activity and self-perceived health status in all groups, although women were more affected. The scores relating to vitality and physical activity were found to be significantly associated with forced vital capacity and lung volumes. Tidal volume was associated with maximal inspiratory and expiratory pressures, inspiratory capacity, and maximum voluntary ventilation. The respiratory rate to tidal volume ratio was inversely associated with the first three of these variables. Conclusions: A very slight restrictive pattern and a reduction in inspiratory muscle strength were observed. The HRQL domains most affected were those related to physical activity and the patients' self-perceived health status. The weakness of the respiratory muscles contributes to the abnormalities observed in lung function and to the deterioration of health-related quality of life

[Exhaled breath condensate: standardized collection of samples from healthy volunteers]. / Condensado de aire espirado: estandarización de la recogida de muestras en voluntarios sanos.

Expired breath condensate collection is a noninvasive technique for obtaining a sample in which to analyze substances that reflect the functional status of the lung and other tissues. Twenty healthy volunteers provided 3 expired breath samples: the second was collected 20 minutes after the first and the third 48 hours after the first. The air and condensate volumes were assessed. The mean (SD) volume of condensate in exhaled air over a period of 15 minutes was 1.8 (0.5) mL (95% confidence interval [CI], 1.5-2 mL) and the coefficient of variation was 29%. Analysis of variance in the 3 samples demonstrated no significant differences. The mean volume of air inhaled over 15 minutes was 119 (25) L (95% CI, 112-125 L). These results indicate that it takes at least 15 minutes and the inhalation of some 120 L of air to collect a condensate volume that exceeds 1.5 mL, sufficient to allow distribution in aliquots to analyze fundamental physical and chemical properties (conductivity, pH) and certain relevant biomarkers.

Condensado de aire espirado: estandarización de la recogida de muestras en voluntarios sanos / Exhaled breath condensate: standardized collection of samples from healthy volunteers

El condensado de aire espirado (CAE) es una técnica no invasiva que permite la obtención de un conjunto de sustancias que expresan el estado funcional del pulmón y otros tejidos. A 20 voluntarios sanos se les realizó un total de 3 pruebas a cada uno: una primera recogida, seguida de otra a los 20 min y la última a las 48 h de la inicial. Al final de la prueba se estimaron el volumen de muestra de condensado obtenida y el volumen de aire movilizado. La media (± desviación estándar) del volumen de muestra de CAE recolectado en 15 min fue de 1,8 ± 0,5 ml, con un intervalo de confianza (IC) del 95% de 1,5 a 2 ml y un coeficiente de variación del 29%. El análisis de la variancia entre las 3 muestras analizadas no mostró diferencias estadísticamente significativas. La media del volumen de aire inspirado en los 15 min fue de 119 ± 25 l, con un IC del 95% de 112 a 125 l. Nuestros resultados indican que para obtener un volumen de muestra superior a 1,5 ml son necesarios al menos 15 min de recogida y haber movilizado unos 120 l de aire, lo que permite la distribución en alícuotas para analizar los componentes físicos y químicos básicos (conductividad, pH) y ciertos biomarcadores de interés

Expired breath condensate collection is a noninvasive technique for obtaining a sample in which to analyze substances that reflect the functional status of the lung and other tissues. Twenty healthy volunteers provided 3 expired breath samples: the second was collected 20 minutes after the first and the third 48 hours after the first. The air and condensate volumes were assessed. The mean (SD) volume of condensate in exhaled air over a period of 15 minutes was 1.8 (0.5) mL (95% confidence interval [CI], 1.5-2 mL) and the coefficient of variation was 29%. Analysis of variance in the 3 samples demonstrated no significant differences. The mean volume of air inhaled over 15 minutes was 119 (25) L (95% CI, 112-125 L). These results indicate that it takes at least 15 minutes and the inhalation of some 120 L of air to collect a condensate volume that exceeds 1.5 mL, sufficient to allow distribution in aliquots to analyze fundamental physical and chemical properties (conductivity, pH) and certain relevant biomarkers

Heme-CO religation in photolyzed hemoglobin: a time-resolved Raman study of the Fe-CO stretching mode.

Time-resolved resonance Raman spectroscopy has been employed to monitor geminate heme-CO rebinding in photolyzed HbCO. The excitation frequency was tuned to enhance the scattering from rebound heme sites 20-500 ns subsequent to CO photolysis. The behavior of vFe-C during ligand rebinding has important ramifications concerning heme pocket dynamics of the distinct equilibrium configurations of the six-coordinate heme sites. During the geminate phase of recombination, the Fe-CO bond strengths and configurations of the rebound sites (inferred from the positions and line widths of vFe-C) were found to be the same as those of equilibrium configurations of HbCO within 500 ns of CO photolysis for all samples. No evidence was found for the existence of transient metastable configurations during geminate recombination. Spectra obtained at earlier times (100 ns) revealed small differences in the geminate rebinding rates of the two equilibrium configurations. Since there is little or no further CO rebinding between 100 and 500 ns after photolysis, some interconversion must occur between the dominant HbCO configurations on a submicrosecond time scale.