Secondary Response to Chronic Respiratory Acidosis in Humans: A Prospective Study.

INTRODUCTION: The magnitude of the secondary response to chronic respiratory acidosis, that is, change in plasma bicarbonate concentration ([HCO3-]) per mm Hg change in arterial carbon dioxide tension (PaCO2), remains uncertain. Retrospective observations yielded Δ[HCO3-]/ΔPaCO2 slopes of 0.35 to 0.51 mEq/l per mm Hg, but all studies have methodologic flaws. METHODS: We studied prospectively 28 stable outpatients with steady-state chronic hypercapnia. Patients did not have other disorders and were not taking medications that could affect acid-base status. We obtained 2 measurements of arterial blood gases and plasma chemistries within a 10-day period. RESULTS: Steady-state PaCO2 ranged from 44.2 to 68.8 mm Hg. For the entire cohort, mean (± SD) steady-state plasma acid-base values were as follows: PaCO2, 52.8 ± 6.0 mm Hg; [HCO3-], 29.9 ± 3.0 mEq/l, and pH, 7.37 ± 0.02. Least-squares regression for steady-state [HCO3-] versus PaCO2 had a slope of 0.476 mEq/l per mm Hg (95% CI = 0.414-0.538, P < 0.01; r = 0.95) and that for steady-state pH versus PaCO2 had a slope of -0.0012 units per mm Hg (95% CI = -0.0021 to -0.0003, P = 0.01; r = -0.47). These data allowed estimation of the 95% prediction intervals for plasma [HCO3-] and pH at different levels of PaCO2 applicable to patients with steady-state chronic hypercapnia. CONCLUSION: In steady-state chronic hypercapnia up to 70 mm Hg, the Δ[HCO3-]/ΔPaCO2 slope equaled 0.48 mEq/l per mm Hg, sufficient to maintain systemic acidity between the mid-normal range and mild acidemia. The estimated 95% prediction intervals enable differentiation between simple chronic respiratory acidosis and hypercapnia coexisting with additional acid-base disorders.

Recomendaciones prácticas para el manejo de la crisis asmática en pacientes adultos / Practical Recommendations for the Management of Acute Asthma in Adult Patients

Las exacerbaciones de asma pueden ser graves y ponen en riesgo la vida de los pacientes. En estos casos es fundamental reconocer signos y síntomas de riesgo, incluyendo la medición de la obstrucción al flujo aéreo y la oximetría de pulso, con la finalidad de objetivar la gravedad de la crisis. La administración adecuada del tratamiento incluyendo broncodilatadores, corticoesteroides y oxigenoterapia permite revertir la obstrucción bronquial y preservar la vida del paciente. A pesar de estas premisas básicas en el manejo de la crisis asmática, en nuestro medio se ha detectado recurrentemente una atención defciente de estos eventos. El contar con recomendaciones de fácil implementación, adecuadas a las necesidades locales y desarrolladas por médicos especialistas en medicina respiratoria podría mejorar la calidad de atención de estos pacientes. Con este objetivo se realizó una revisión bibliográfica clasificando la información según el grado de evidencia. Los resultados fueron evaluados por un panel de expertos y se desarrolló un algoritmo de manejo del asma aguda. El algoritmo propone una evaluación inicial en base a signos de severidad, datos de medición del flujo aéreo (FEV1 y/o FPE) y oximetría de pulso que permitirán clasificar las exacerbaciones según su grado de severidad e indicar detalladamente los pasos terapéuticos a seguir en cada caso, como así también los criterios de internación y alta. El uso de estas recomendaciones permitirá una mejor distribución de recursos y optimización del tratamiento de los pacientes atendidos por exacerbaciones de asma.

Asthma exacerbations can be severe and life threatening. In order to assess in a correct and objective way the severity of the exacerbation, it is essential to recognize risk signs and symptoms, including the measurement of airflow obstruction and pulse oximetry. Proper treatment including bronchodilators, corticosteroids, and oxygen can reverse bronchial obstruction and preserve patient's life. Despite these basic facts, inappropriate care in the management of acute asthma events is frequent in Argentina. Recommendations developed by specialists in respiratory medicine, which are easy to implement and adapted to local needs, could improve the quality of care of these patients. In order to accomplish these goals, an exhaustive review of the literature was conducted and the information was classified according to the degree of evidence. The results were evaluated by a panel of experts and an algorithm for the management of acute asthma was designed. This algorithm proposes an initial assessment based on asthma severity including measurement of airflow obstruction (FEV1 and/or PF) and pulse oximetry. Thus, it allows classifying exacerbations by degree of severity, leading to appropriate sequential therapeutic options as well as criteria for admission and discharge. The use of these recommendations is intended to allow a correct management of asthma exacerbations in Argentina and an optimized use of medical resources.

Acid-base patterns in acute severe asthma.

BACKGROUND AND OBJECTIVES: Acid-base status in acute severe asthma (ASA) remains undefined; some studies report complete absence of metabolic acidosis, whereas others describe it as present in one fourth of patients or more. Conclusion discrepancies would therefore appear to derive from differences in assessment methodology. Only a systematic approach centering on patient clinical findings can correctly establish true acid-base disorder prevalence levels. METHODS: This study examines acid-base patterns in ASA (314 patients), taking into account both natural history of disease and treatment, in patients free of other diseases altering acid-base status. Data were collected from patients admitted for ASA without prior history of chronic bronchitis, emphysema, kidney or liver disease, heart failure, uncontrolled diabetes mellitus or gastrointestinal illness. Informed consent was obtained for all patients, after study protocol approval by the Institutional Review Board. RESULTS: Arterial blood gases, plasma electrolytes, lactate levels, and FEV(1) were measured on arrival. Severe airway obstruction was found with FEV(1) values of 25.6 ± 10.0%, substantial hypoxemia (PaO(2) 66.1 ± 11.9 mmHg) and increased A-a O(2) gradient (39.3 ± 12.3 mmHg) breathing room air. While respiratory alkalosis occurred in patients with better preservation of FEV1, respiratory acidosis was observed with more severe airway obstruction, as was increased lactate in the majority of patients, independent of PaO(2) and PaCO(2) levels. CONCLUSIONS: Predominant acid-base patterns observed in ASA in this patient population included primary hypocapnia, or less frequently, primary hypercapnia. Lactic acidosis occurred in 11% of patients and presented consistently as a mixed acid-base disorder. These findings suggest lactic acidosis results from the combined effects of both ASA and medication-related sympathetic effects.

Decline of outpatient asthma management in Argentina.

BACKGROUND AND OBJECTIVES: To assess management of adult patients admitted with acute asthma and compare the results obtained with a similar study 5 years earlier. METHODS: A cross-sectional survey of 211 consecutive patients admitted to hospital during a 12-month period was conducted. Patients were surveyed using a validated management questionnaire and the results compared with those of the previous survey. RESULTS: There were 211 patients in the present survey and patient demographics were similar in both populations studied. Comparison of the previous to the current survey showed significant differences in predicted FEV(1)% at admission (30.2 +/- 10.7 vs 23.9 +/- 8.9, respectively, P < 0.001), and the average number of hospital admissions in the year prior to the survey (0.7 +/- 1.2 vs 1.3 +/- 0.7, P < 0.0001). In the present survey, more patients changed their medication after acute exacerbation and more received an action plan. Compared with the previous survey, there were no significant differences between the mean number of emergency department visits, need for mechanical ventilation, number of patients prescribed inhaled corticosteroids and other related variables. CONCLUSION: Compared with the previous study the severity of asthma at the time of admission was worse. Some of the recommended international asthma management programmes appear to have been followed.

[Argentine consensus of non-invasive ventilation]. / Consenso argentino de ventilación no invasiva.

Non-invasive ventilation (NIV) is nowadays increasingly used. The significant decrease in tracheal intubation related complications makes it particularly attractive in patients with moderately acute respiratory failure (ARF) who still have some degree of respiratory autonomy. It has also been used to support patients with chronic respiratory failure. However, final outcomes are variable according to the conditions which determined its application. This Consensus was performed in order to review the evidence supporting the use of positive pressure NIV. The patho-physiological background of NIV and the equipment required technology are described. Available evidence clearly suggests benefits of NIV in acute exacerbation of chronic obstructive pulmonary disease (COPD) and in cardiogenic pulmonary edema (Recommendation A). When considering ARF in the setting of acute respiratory distress syndrome results are uncertain, unless dealing with immunosupressed patients (Recommendation B). Positive results are also shown in weaning of mechanical ventilation (MV), particularly regarding acute exacerbation of COPD patients (Recommendation A). An improved quality of life in chronic respiratory failure and a longer survival in restrictive disorders has also been shown (Recommendation B) while its benefit in stable COPD patients is still controversial (Recommendation C). NIV should be performed according to pre-established standards. A revision of NIV related complications is performed and the cost-benefit comparison with invasive MV is also considered.

Adequacy of outpatient management of asthma patients admitted to a state hospital in Argentina.

OBJECTIVE: The aim of this study was to assess chronic outpatient management of adult patients admitted with asthma. METHODOLOGY: A cross-sectional survey was conducted of 98 consecutive asthma admissions to a specialized pulmonary State Hospital in Buenos Aires, Argentina, over a 12-month period. Patients were surveyed, within 48 h of admission, with a previously validated questionnaire which deals with chronic outpatient management and measures taken by patients or physicians to treat symptoms during asthma exacerbations. RESULTS: FEV1% predicted was 30.2 +/- 10.7. Mean admission rate and emergency department (ED) visits in the previous year were 0.7 +/- 1.2 and 4.6 +/- 5.1, respectively. A total of 96, 65 and 9% of the patients had been treated previously in the ED, admitted to hospital or mechanically ventilated, respectively. Only 62% had been prescribed inhaled corticosteroids (IC) by their physician; 38% had been prescribed nebulized beta agonists (Nbeta2) and 68% a metered dose inhaler (MDIbeta2). Inhaled beta2-agonist usage during acute exacerbations over the 24 h prior to admission was 14.4 +/- 7.4 puffs for MDIbeta2 and 8.6 +/- 5.4 occasions for Nbeta2. Only 11% of the patients were able to perform all the steps of the MDI inhalation technique correctly. An action plan had been provided by their physicians to 43% of patients, while 58% changed their medication on their own. Only three patients had a peak flow meter (PFM) prescribed. ED was used by 26% for their routine care. No health insurance coverage was available to 75.5% of the patients. CONCLUSIONS: Underuse of IC, poor MDI inhalation technique, and low prescription of an action plan was common and a PFM was seldom prescribed. During exacerbations, many patients changed their medication spontaneously and MDIbeta2 underuse was observed.

Consenso argentino de ventilación no invasiva. / [Argentine consensus of non-invasive ventilation]

Non-invasive ventilation (NIV) is nowadays increasingly used. The significant decrease in tracheal intubation related complications makes it particularly attractive in patients with moderately acute respiratory failure (ARF) who still have some degree of respiratory autonomy. It has also been used to support patients with chronic respiratory failure. However, final outcomes are variable according to the conditions which determined its application. This Consensus was performed in order to review the evidence supporting the use of positive pressure NIV. The patho-physiological background of NIV and the equipment required technology are described. Available evidence clearly suggests benefits of NIV in acute exacerbation of chronic obstructive pulmonary disease (COPD) and in cardiogenic pulmonary edema (Recommendation A). When considering ARF in the setting of acute respiratory distress syndrome results are uncertain, unless dealing with immunosupressed patients (Recommendation B). Positive results are also shown in weaning of mechanical ventilation (MV), particularly regarding acute exacerbation of COPD patients (Recommendation A). An improved quality of life in chronic respiratory failure and a longer survival in restrictive disorders has also been shown (Recommendation B) while its benefit in stable COPD patients is still controversial (Recommendation C). NIV should be performed according to pre-established standards. A revision of NIV related complications is performed and the cost-benefit comparison with invasive MV is also considered.

[Survey on changes in asthma treatment and management]. / Encuesta sobre cambios en el manejo y tratamiento del asma bronquial.

A total of 518 chest physicians selected at random from a national list participated in a survey on asthma management. This paper dealt with queries about diagnostic procedures, methods for recognizing life-threatening asthma attacks, patient education and treatment for acute asthma in adults and in children older than 6 years. A total of 198 replies were received (38.2% of questionnaires mailed). A mean score of frequency of use (from 0 = never to 3 = always) was used for assessing the responses. Results were compared with a similar survey performed in 1994, disclosing a satisfactory trend in diagnostic tests with the bronchodilator test and in oral steroid courses (2.74 +/- 2.3 vs 2.30 +/- 1.05 and 1.26 +/- 0.96 vs 0.98 +/- 0.84, respectively). Skin tests were less used (0.50 +/- 0.83 vs 0.88 +/- 1.08). Results reporting how to assess the severity of asthma attacks, such as taking into account symptoms or drop in PEFR, were more frequent in the present study (2.65 +/- 0.66 vs 2.29 +/- 0.90 and 1.93 +/- 1.05 vs 1.51 +/- 1.20, respectively). PEFR or spirometry used by the physician for assessing severity of asthma attacks was not always performed and its comparison was no better than in 1994 (2.14 +/- 1.04 vs 2.13 +/- 0.70). Data regarding patient information and education ranked equal or better than in the 1994 survey. For the treatment of acute severe episodes, almost all responders in the present study chose inhaled 12 agonists (IBA) for adults and children, thus improving with respect to the previous study (first option 85.3 vs 57.5% and 81.0 vs 63.4%, respectively). For maintenance therapy, a good trend was also observed with more responders who now chose inhaled steroid (IS) as a first choice formulation, specially in children (2.09 +/- 1.01 vs 1.61 +/- 1.00). The average normal and maximal daily doses of IS for adults and children were higher than in 1994 and were now in agreement with recommended doses. The recommendation of short acting IBA for treating and preventing symptoms was noticeably less frequent in the present study either for adults or for children (0.40 +/- 0.78 vs 1.23 +/- 1.10 and 0.21 +/- 0.58 vs 1.23 +/- 1.00, respectively). Hyposensitization was less recommended than in 1994. Despite a tendency to improve treatment and management, considerable differences with asthma guidelines still remain.

[Survey of chest physicians regarding COPD diagnosis and treatment]. / Encuesta a neumonólogos sobre el diagnóstico y tratamiento de EPOC.

A survey on COPD diagnostic procedures, treatment and management was conducted in a group of 517 chest physicians randomized from a list of the 1121 affiliates to the Asociación Argentina de Medicina Respiratoria. One hundred eighty-seven responses were obtained (36.2% of the questionnaires mailed). They treat an average of 53.3 COPD patients every month. Twenty-four percent of them had mild, 41.8% moderate and 33.8% severe disease (GOLD criteria). Only clinical criteria for diagnosis of COPD, clinical criteria + spirometry (S), and clinical criteria + S + chest X ray were used by 2.9, 23.4 and 73.7% of responders, respectively. Seventy percent of responders believed that chronic asthma without bronchodilator response must be included in the COPD definition. Only 14.1% of responders performed S in every office visit. Cardiac function was assessed using clinical criteria, electrocardiogram and echocardiogram by 90.6, 80.6 and 73.8% of responders, respectively, while 98.3% stated that they trained most of their patients in the inhalation technique. Metered Dose Inhaled was the first option for bronchodilators administration (64.8%) followed by nebulization (16.5%), dry powder inhalation (13.7%) and oral administration (4.8%). First option for chronic therapy in severe COPD patients was the association of anticholinergic drug (AC) + short acting beta2-agonists (SABA) (65.5%), AC alone (18.8%), long acting beta2-agonists (LABA) (9.7%), inhaled corticosteroids (IC) (3.5%) and SABA alone (2.8%). Corticosteroids and antibiotics were prescribed in severe COPD exacerbation by 92.5 and 70% of responders, respectively. First choice antibiotic formulation was beta-lactamics + beta-lactamase inhibitors in 39% of the responders followed by fluorquinolones in 23.7%, macrolides in 17.5% and beta-lactamics in 12.5%. Lastly, 12.7% of COPD patients received long-term domiciliary oxygen therapy. 59.3% of them were prescribed pulmonary rehabilitation, 94.1% vaccination against influenza and 91.4% pneumococcal vaccination. Thirty seven percent of the patients continued to smoke. Most of reponses regarding diagnosis and exacerbation treatment were in agreement with recommendations of international guidelines. For maintenance treatment the association of AC + SABA was commonly recommended as first option, whereas IC and LABA were rarely prescribed.

Encuesta sobre cambios en el manejo y tratamiento del asma bronchial / Survey on changes in asthma treatment and management

Se realizó una encuesta a 518 especialistas de enfermedades respiratorias de un listado de la totalidad del país. Esta se refería al manejo y al tratamiento del acceso agudo y especialmente al asma estable, en adultos y en niños mayores de 6 años. Se obtuvieron 198 respuestas (38.2% de los cuestionarios enviados). Se compararon los resultados con los obtenidos en una encuesta realizada en 1994. Las respuestas se evaluaron como 0 (nunca), 1 (algunas veces), 2 (a menudo), 3 (siempre). Con estos valores se calculó un puntaje medio. Respecto a 1994 se encontró una buena tendencia referente al enfoque diagnóstico con más utilización de la prueba de reversibilidad a los broncodilatadores (2.74 ±2.3 vs 2.30±1.05) y la prueba terapéutica con corticoides (1.26±0.96 vs 0.98±0.84) y menor utilización de las pruebas cutáneas (0.50±0.83 vs 0.88±1.08). Referente al consejo de utilizar la sintomatología o el descenso del pico flujo espiratorio para reconocer el ataque del asma, ambos mejoraron significativamente (2.65±0.66 vs 2.29±0.90 y 1.93±1.05 vs 1.51±1.20, respectivamente). Criterios objetivos para evaluar el ataque de asma no siempre son utilizados por parte del médico y no mejoraron respecto a 1994 (2.14±1.04 vs 2.13±0.70). Referente al tratamiento en agudo, este enfoque mejoró notablemente con la casi totalidad de los encuestados que recomiendan β2 agonistas inhalados tanto en adultos como en niños (primera opción de tratamiento 85.3 vs 57.5% y 81.0 vs 63.4%, respectivamente). En el tratamiento de mantenimiento, se observó una mayor utilización de corticoides inhalados, sobre todo en los niños (2.09±1.01 vs 1.61±1.00), con dosis ahora correctas. Se observó menor utilización de β2 agonistas de acción corta en el tratamiento continuo, 0.40±0.78 vs 1.23±1.10 y 0.21±0.58 vs 1.23±1.00 en adultos y niños, respectivamente. A pesar de esta tendencia positiva en el manejo y tratamiento de asma bronquial no todo está de acuerdo con las pautas de calidad aceptadas o con los guías de manejo de la enfermedad.

Encuesta sobre cambios en el manejo y tratamiento del asma bronchial / Survey on changes in asthma treatment and management

Se realizó una encuesta a 518 especialistas de enfermedades respiratorias de un listado de la totalidad del país. Esta se refería al manejo y al tratamiento del acceso agudo y especialmente al asma estable, en adultos y en niños mayores de 6 años. Se obtuvieron 198 respuestas (38.2% de los cuestionarios enviados). Se compararon los resultados con los obtenidos en una encuesta realizada en 1994. Las respuestas se evaluaron como 0 (nunca), 1 (algunas veces), 2 (a menudo), 3 (siempre). Con estos valores se calculó un puntaje medio. Respecto a 1994 se encontró una buena tendencia referente al enfoque diagnóstico con más utilización de la prueba de reversibilidad a los broncodilatadores (2.74 ±2.3 vs 2.30±1.05) y la prueba terapéutica con corticoides (1.26±0.96 vs 0.98±0.84) y menor utilización de las pruebas cutáneas (0.50±0.83 vs 0.88±1.08). Referente al consejo de utilizar la sintomatología o el descenso del pico flujo espiratorio para reconocer el ataque del asma, ambos mejoraron significativamente (2.65±0.66 vs 2.29±0.90 y 1.93±1.05 vs 1.51±1.20, respectivamente). Criterios objetivos para evaluar el ataque de asma no siempre son utilizados por parte del médico y no mejoraron respecto a 1994 (2.14±1.04 vs 2.13±0.70). Referente al tratamiento en agudo, este enfoque mejoró notablemente con la casi totalidad de los encuestados que recomiendan β2 agonistas inhalados tanto en adultos como en niños (primera opción de tratamiento 85.3 vs 57.5% y 81.0 vs 63.4%, respectivamente). En el tratamiento de mantenimiento, se observó una mayor utilización de corticoides inhalados, sobre todo en los niños (2.09±1.01 vs 1.61±1.00), con dosis ahora correctas. Se observó menor utilización de β2 agonistas de acción corta en el tratamiento continuo, 0.40±0.78 vs 1.23±1.10 y 0.21±0.58 vs 1.23±1.00 en adultos y niños, respectivamente. A pesar de esta tendencia positiva en el manejo y tratamiento de asma bronquial no todo está de acuerdo con las pautas de calidad aceptadas o con los guías de manejo de la enfermedad.(AU)

Encuesta sobre cambios en el manejo y tratamiento del asma bronquial. / [Survey on changes in asthma treatment and management]

A total of 518 chest physicians selected at random from a national list participated in a survey on asthma management. This paper dealt with queries about diagnostic procedures, methods for recognizing life-threatening asthma attacks, patient education and treatment for acute asthma in adults and in children older than 6 years. A total of 198 replies were received (38.2

of questionnaires mailed). A mean score of frequency of use (from 0 = never to 3 = always) was used for assessing the responses. Results were compared with a similar survey performed in 1994, disclosing a satisfactory trend in diagnostic tests with the bronchodilator test and in oral steroid courses (2.74 +/- 2.3 vs 2.30 +/- 1.05 and 1.26 +/- 0.96 vs 0.98 +/- 0.84, respectively). Skin tests were less used (0.50 +/- 0.83 vs 0.88 +/- 1.08). Results reporting how to assess the severity of asthma attacks, such as taking into account symptoms or drop in PEFR, were more frequent in the present study (2.65 +/- 0.66 vs 2.29 +/- 0.90 and 1.93 +/- 1.05 vs 1.51 +/- 1.20, respectively). PEFR or spirometry used by the physician for assessing severity of asthma attacks was not always performed and its comparison was no better than in 1994 (2.14 +/- 1.04 vs 2.13 +/- 0.70). Data regarding patient information and education ranked equal or better than in the 1994 survey. For the treatment of acute severe episodes, almost all responders in the present study chose inhaled 12 agonists (IBA) for adults and children, thus improving with respect to the previous study (first option 85.3 vs 57.5

and 81.0 vs 63.4

, respectively). For maintenance therapy, a good trend was also observed with more responders who now chose inhaled steroid (IS) as a first choice formulation, specially in children (2.09 +/- 1.01 vs 1.61 +/- 1.00). The average normal and maximal daily doses of IS for adults and children were higher than in 1994 and were now in agreement with recommended doses. The recommendation of short acting IBA for treating and preventing symptoms was noticeably less frequent in the present study either for adults or for children (0.40 +/- 0.78 vs 1.23 +/- 1.10 and 0.21 +/- 0.58 vs 1.23 +/- 1.00, respectively). Hyposensitization was less recommended than in 1994. Despite a tendency to improve treatment and management, considerable differences with asthma guidelines still remain.

Encuesta a neumonólogos sobre el diagnóstico y tratamiento de EPOC. / [Survey of chest physicians regarding COPD diagnosis and treatment]

A survey on COPD diagnostic procedures, treatment and management was conducted in a group of 517 chest physicians randomized from a list of the 1121 affiliates to the Asociación Argentina de Medicina Respiratoria. One hundred eighty-seven responses were obtained (36.2

of the questionnaires mailed). They treat an average of 53.3 COPD patients every month. Twenty-four percent of them had mild, 41.8

moderate and 33.8

severe disease (GOLD criteria). Only clinical criteria for diagnosis of COPD, clinical criteria + spirometry (S), and clinical criteria + S + chest X ray were used by 2.9, 23.4 and 73.7

of responders, respectively. Seventy percent of responders believed that chronic asthma without bronchodilator response must be included in the COPD definition. Only 14.1

of responders performed S in every office visit. Cardiac function was assessed using clinical criteria, electrocardiogram and echocardiogram by 90.6, 80.6 and 73.8

of responders, respectively, while 98.3

stated that they trained most of their patients in the inhalation technique. Metered Dose Inhaled was the first option for bronchodilators administration (64.8

) followed by nebulization (16.5

), dry powder inhalation (13.7

) and oral administration (4.8

). First option for chronic therapy in severe COPD patients was the association of anticholinergic drug (AC) + short acting beta2-agonists (SABA) (65.5

), AC alone (18.8

), long acting beta2-agonists (LABA) (9.7

), inhaled corticosteroids (IC) (3.5

) and SABA alone (2.8

). Corticosteroids and antibiotics were prescribed in severe COPD exacerbation by 92.5 and 70

of responders, respectively. First choice antibiotic formulation was beta-lactamics + beta-lactamase inhibitors in 39

of the responders followed by fluorquinolones in 23.7

, macrolides in 17.5

and beta-lactamics in 12.5

. Lastly, 12.7

of COPD patients received long-term domiciliary oxygen therapy. 59.3

of them were prescribed pulmonary rehabilitation, 94.1

vaccination against influenza and 91.4

pneumococcal vaccination. Thirty seven percent of the patients continued to smoke. Most of reponses regarding diagnosis and exacerbation treatment were in agreement with recommendations of international guidelines. For maintenance treatment the association of AC + SABA was commonly recommended as first option, whereas IC and LABA were rarely prescribed.

[Gas exchange in acute respiratory distress syndrome]. / Intercambio gaseoso en el síndrome de dificultad respiratoria aguda.

The hypoxemia of acute respiratory distress syndrome (ARDS) depends chiefly upon shunt and ventilation-perfusion (VA/Q) inequality produced by fluid located in the interstitial space, alveolar collapse and flooding. Variables other tham inspired oxygen fraction and the underlying physiological abnormality can influence arterial oxygen partial pressure (PaO2). Changes in cardiac output, hemoglobin concentration, oxygen consumption and alcalosis can cause changes in PaO2 through their influence on mixed venous PO2. Gas exchange (GE) in ARDS may be studied using the inert gas elimination technique (MIGET) which enables to define the distribution of ventilation and perfusion without necessarily altering the FIO2 differentiating shunt from lung units with low VA/Q ratios and dead space from lung units with high VA/Q ratios. Different ventilatory strategies that increase mean airway pressure (positive end-expiratory pressure, high tidal volumes, inverse inspiratory-expiratory ratio, etc) improve PaO2 through increasing lung volume by recruiting new open alveoli and spreading the intra-alveolar fluid over a large surface area. Also prone-position ventilation would result in a marked improvement in GE enhancing dorsal lung ventilation by the effects on the gravitional distribution of pleural pressure and the reduction in the positive pleural pressure that develops in dorsal regions in ARDS. Inhaled nitric oxide (NO) has been shown to increase PaO2 in ARDS patients by inducing vasodilation predominantly in ventilated areas redistributing pulmonary blood flow away from nonventilated toward ventilated areas of the lung thus resulting in a shunt reduction. On the same way inhaled prostaglandins (PGI2 or PGE1) causes selective pulmonary vasodilation improving pulmonary GE. Intravenous almitrine, a selective pulmonary vasoconstrictor, has been shown to increase PaO2 by increasing hypoxic pulmonary vasoconstriction. A synergistic effect was found between inhaled NO and almitrine. In spite of the improval of GE shown by these different techniques on ARDS, no effect was demonstrated on mortality or duration of mechanical ventilation.

Intercambio gaseoso en el sindrome de dificultad respiratoria aguda / Gas exchange in acute respiratory distress syndrome

The hypoxemia of acute respiratory distress syndrome (ARDS) depends chiefly upon shunt and ventilation-perfusion (VA/Q) inequality produced by fluid located in the interstitial space, alveolar collapse and flooding. Variables other tham inspired oxygen fraction and the underlying physiological abnormality can influence arterial oxygen partial pressure (PaO2). Changes in cardiac output, hemoglobin concentration, oxygen consumption and alcalosis can cause changes in PaO2 through their influence on mixed venous PO2. Gas exchange (GE) in ARDS may be studied using the inert gas elimination technique (MIGET) which enables to define the distribution of ventilation and perfusion without necessarily altering the FIO2 differentiating shunt from lung units with low VA/Q ratios and dead space from lung units with high VA/Q ratios. Different ventilatory strategies that increase mean airway pressure (positive end-expiratory pressure, high tidal volumes, inverse inspiratory-expiratory ratio, etc) improve PaO2 through increasing lung volume by recruiting new open alveoli and spreading the intra-alveolar fluid over a large surface area. Also prone-position ventilation would result in a marked improvement in GE enhancing dorsal lung ventilation by the effects on the gravitional distribution of pleural pressure and the reduction in the positive pleural pressure that develops in dorsal regions in ARDS. Inhaled nitric oxide (NO) has been shown to increase PaO2 in ARDS patients by inducing vasodilation predominantly in ventilated areas redistributing pulmonary blood flow away from nonventilated toward ventilated areas of the lung thus resulting in a shunt reduction. On the same way inhaled prostaglandins (PGI2 or PGE1) causes selective pulmonary vasodilation improving pulmonary GE. Intravenous almitrine, a selective pulmonary vasoconstrictor, has been shown to increase PaO2 by increasing hypoxic pulmonary vasoconstriction. A synergistic effect was found between inhaled NO and almitrine. In spite of the improval of GE shown by these different techniques on ARDS, no effect was demonstrated on mortality or duration of mechanical ventilation

Intercambio gaseoso en el sindrome de dificultad respiratoria aguda / Gas exchange in acute respiratory distress syndrome

The hypoxemia of acute respiratory distress syndrome (ARDS) depends chiefly upon shunt and ventilation-perfusion (VA/Q) inequality produced by fluid located in the interstitial space, alveolar collapse and flooding. Variables other tham inspired oxygen fraction and the underlying physiological abnormality can influence arterial oxygen partial pressure (PaO2). Changes in cardiac output, hemoglobin concentration, oxygen consumption and alcalosis can cause changes in PaO2 through their influence on mixed venous PO2. Gas exchange (GE) in ARDS may be studied using the inert gas elimination technique (MIGET) which enables to define the distribution of ventilation and perfusion without necessarily altering the FIO2 differentiating shunt from lung units with low VA/Q ratios and dead space from lung units with high VA/Q ratios. Different ventilatory strategies that increase mean airway pressure (positive end-expiratory pressure, high tidal volumes, inverse inspiratory-expiratory ratio, etc) improve PaO2 through increasing lung volume by recruiting new open alveoli and spreading the intra-alveolar fluid over a large surface area. Also prone-position ventilation would result in a marked improvement in GE enhancing dorsal lung ventilation by the effects on the gravitional distribution of pleural pressure and the reduction in the positive pleural pressure that develops in dorsal regions in ARDS. Inhaled nitric oxide (NO) has been shown to increase PaO2 in ARDS patients by inducing vasodilation predominantly in ventilated areas redistributing pulmonary blood flow away from nonventilated toward ventilated areas of the lung thus resulting in a shunt reduction. On the same way inhaled prostaglandins (PGI2 or PGE1) causes selective pulmonary vasodilation improving pulmonary GE. Intravenous almitrine, a selective pulmonary vasoconstrictor, has been shown to increase PaO2 by increasing hypoxic pulmonary vasoconstriction. A synergistic effect was found between inhaled NO and almitrine. In spite of the improval of GE shown by these different techniques on ARDS, no effect was demonstrated on mortality or duration of mechanical ventilation (AU)

Intercambio gaseoso en el síndrome de dificultad respiratoria aguda. / [Gas exchange in acute respiratory distress syndrome]

The hypoxemia of acute respiratory distress syndrome (ARDS) depends chiefly upon shunt and ventilation-perfusion (VA/Q) inequality produced by fluid located in the interstitial space, alveolar collapse and flooding. Variables other tham inspired oxygen fraction and the underlying physiological abnormality can influence arterial oxygen partial pressure (PaO2). Changes in cardiac output, hemoglobin concentration, oxygen consumption and alcalosis can cause changes in PaO2 through their influence on mixed venous PO2. Gas exchange (GE) in ARDS may be studied using the inert gas elimination technique (MIGET) which enables to define the distribution of ventilation and perfusion without necessarily altering the FIO2 differentiating shunt from lung units with low VA/Q ratios and dead space from lung units with high VA/Q ratios. Different ventilatory strategies that increase mean airway pressure (positive end-expiratory pressure, high tidal volumes, inverse inspiratory-expiratory ratio, etc) improve PaO2 through increasing lung volume by recruiting new open alveoli and spreading the intra-alveolar fluid over a large surface area. Also prone-position ventilation would result in a marked improvement in GE enhancing dorsal lung ventilation by the effects on the gravitional distribution of pleural pressure and the reduction in the positive pleural pressure that develops in dorsal regions in ARDS. Inhaled nitric oxide (NO) has been shown to increase PaO2 in ARDS patients by inducing vasodilation predominantly in ventilated areas redistributing pulmonary blood flow away from nonventilated toward ventilated areas of the lung thus resulting in a shunt reduction. On the same way inhaled prostaglandins (PGI2 or PGE1) causes selective pulmonary vasodilation improving pulmonary GE. Intravenous almitrine, a selective pulmonary vasoconstrictor, has been shown to increase PaO2 by increasing hypoxic pulmonary vasoconstriction. A synergistic effect was found between inhaled NO and almitrine. In spite of the improval of GE shown by these different techniques on ARDS, no effect was demonstrated on mortality or duration of mechanical ventilation.

Encuesta a médicos especialistas sobre el diagnóstico y el manejo del asma bronquial / Survey among chest physicians regarding the diagnosis and management of asthma

Se realizó una encuesta a un grupo de 300 especialistas de pulmón provenientes de un listado de la totalidad del país. Se analizan aquí las respuestas referidas al manejo del asma (diagnóstico, critérios para reconocer ataques de asma, educación al paciente sobre su enfermedad). Se obtuvieron 98 respuestas (32.7 por ciento de los cuestionarios enviados). Los encuestados se definían especialistas en Neumonología (N) 71 por ciento. N + Medicina Interna (MI) 12 por ciento, N + Alergia (A) 6 por ciento, A 5 por ciento, MI 4 por ciento, MI + 2 por ciento. Referente a diagnóstico se constató que los especialistas utilizan poco la respuesta a broncodilatadores y menos aún la respuesta a corticoides. Utilizan con frecuencia alta y más que la mayoría de los países comparados la eosinofilia en sangre y la IgE RAST, ambos de dudosa necesidad para el diagnóstico de asma bronquial. El reconocimiento de severidad del ataque de asma lo realizan teniendo en cuenta menos que otros países la sintomatología, la falta de respuesta a broncodilatadores y con muy escasa utilización de métodos objetivos para objetivar obstrución de la vía aérea, EJ.; PEFR. Asimismo el PEFR es poco recomendado para el seguimiento de la enfermedad. La correcta técnica de la inhalación, sea aerosol o polvo seco, se realiza con baja frecuencia. Sólo las respuestas referidas a la educación del paciente sobre su enfermedad, la enseñanza, sobre diferencia entre tratamiento broncodilatador y desinflamatorio, comunicación sobre severidad de su enfermedad y frecuencia con que se da al paciente plan de acción en caso de ataque severo de asma calificaron igual o mejor que los países que habitualmente califican bien. Esto, de acuerdo a otros datos de la literatura, nos hace sospechar, como suele ocurrir en estas encuestas, que el entrevistado contesta a veces lo que debería hacer, pero no necesariamente lo que hace.

Encuesta a médicos especialistas sobre el diagnóstico y el manejo del asma bronquial / Survey among chest physicians regarding the diagnosis and management of asthma

Se realizó una encuesta a un grupo de 300 especialistas de pulmón provenientes de un listado de la totalidad del país. Se analizan aquí las respuestas referidas al manejo del asma (diagnóstico, critérios para reconocer ataques de asma, educación al paciente sobre su enfermedad). Se obtuvieron 98 respuestas (32.7 por ciento de los cuestionarios enviados). Los encuestados se definían especialistas en Neumonología (N) 71 por ciento. N + Medicina Interna (MI) 12 por ciento, N + Alergia (A) 6 por ciento, A 5 por ciento, MI 4 por ciento, MI + 2 por ciento. Referente a diagnóstico se constató que los especialistas utilizan poco la respuesta a broncodilatadores y menos aún la respuesta a corticoides. Utilizan con frecuencia alta y más que la mayoría de los países comparados la eosinofilia en sangre y la IgE RAST, ambos de dudosa necesidad para el diagnóstico de asma bronquial. El reconocimiento de severidad del ataque de asma lo realizan teniendo en cuenta menos que otros países la sintomatología, la falta de respuesta a broncodilatadores y con muy escasa utilización de métodos objetivos para objetivar obstrución de la vía aérea, EJ.; PEFR. Asimismo el PEFR es poco recomendado para el seguimiento de la enfermedad. La correcta técnica de la inhalación, sea aerosol o polvo seco, se realiza con baja frecuencia. Sólo las respuestas referidas a la educación del paciente sobre su enfermedad, la enseñanza, sobre diferencia entre tratamiento broncodilatador y desinflamatorio, comunicación sobre severidad de su enfermedad y frecuencia con que se da al paciente plan de acción en caso de ataque severo de asma calificaron igual o mejor que los países que habitualmente califican bien. Esto, de acuerdo a otros datos de la literatura, nos hace sospechar, como suele ocurrir en estas encuestas, que el entrevistado contesta a veces lo que debería hacer, pero no necesariamente lo que hace. (AU)