[Hypercapnic stimulation and ventilation response in the syndrome of sleep obstructive apnea. Comparison of reinhalation and steady state]. / Estimulación hipercápnica y respuesta ventilatoria en el síndrome de apnea obstructiva del sueño. Comparación de reinhalación y estado-estable.

The objective of this study was to assess ventilatory response to stimulation with CO2 in patients suffering obstructive sleep apnea syndrome (OSAS) but without chronic obstructive pulmonary disease (COPD), by examining differences between hyper- and normocapnic patients and comparing the results obtained with the usual techniques used to stimulate hypercapnia (rebreathing and stable-state). To this end, we studied 15 obese patients, all with an apnea-hypopnea index greater than 10 from a polysomnograph lasting a full night. The following lung function tests were performed: spirometry, air way resistance measures and static lung volumes by plethysmograph and arterial gasometry. We later analyzed ventilatory response by the stable-state method, with increasing CO2 concentrations (from 1 to 9%) and by the rebreathing method. Results from the two methods were similar for all patients: delta VE/delta PCO2 (0.64 +/- 0.35 vs 0.67 +/- 0.48 l/min/mmHg; p = 0.59), delta Vt/delta PCO2 (28.33 +/- 16.23 vs 26.42 +/- 16.94 ml/mmHg; p = 0.9), delta Vt/Ti/delta PCO2 (28.82 +/- 20.9 vs 29.41 +/- 23.78 ml/s/mmHg; p = 0.89) y delta P0.1/delta PCO2 (0.11 +/- 0.07 vs 0.117 +/- 0.05 cmH2O/mmHg; p = 0.58). We compared the results obtained by the two techniques by dividing the sample into two groups of 7 and 8 patients, respectively, depending on whether PaCO2 level before stimulation was higher or lower than 45 mmHg. The hypercapnic patients (group I) were older (61 +/- 3.5 vs 50 +/- 9 years; p = 0.04) but were not different with respect to body mass from the normocapnic patients (group II) (37.59 +/- 6.4 vs 34.56 +/- 4.75 kg/m2; p = 0.33). The results from the two techniques for stimulating hypercapnia were similar within each group, with a statistically significant decrease (p < 0.03) in patients with daytime hypercapnia in delta VE/delta PCO2 delta Vt/delta PCO2, delta Vt/Ti/delta PCO2 and delta P0.1/delta PCO2. We conclude that there are no differences in the results obtained with the rebreathing and stable state techniques. Likewise, ventilatory response to stimulation with CO2 in individuals with OSAS and daytime hypoventilation is less than of normocapnic patients.

[Respiratory polygraphy in the diagnosis of obstructive sleep apnea syndrome]. / Poligrafía respiratoria en el diagnóstico del síndrome de apneas obstructivas durante el sueño.

The traditional way of diagnosing obstructive sleep apnea syndrome (OSAS) is all-night polysomnographic recording. A proposed alternative is respiratory polygraphy, a simplified procedure that consists in nighttime monitoring of oxygen saturation, oronasal flow and respiratory movements. Our aim was to evaluate the efficacy of respiratory polygraphy in diagnosing OSAS in comparison with conventional polysomnography. We studied 101 patients (92 men and 9 women) who had undergone polysomnography. An apnea-hypopnea index (AHI) > or = 10 was considered to be the diagnostic criterion for OSAS. To assess the diagnostic validity of respiratory polygraphy we considered that an AHI per hour of recording > or = 10 and a desaturation index per hour of recording > or = 10 were consistent with a diagnosis of OSAS. Sixty patients were diagnosed of OSAS. The AHI per hour of recording was > or = 10 in 56 patients, with 4 false negatives (sensitivity 93.3% and specificity 100%). The desaturation index per hour of recording was > or = 10 in 65 patients, with 7 false positives and 2 false negatives (sensitivity 96.6% and specificity 82.9%). We conclude that respiratory polysomnography is a specific, highly sensitive method for diagnosing OSAS.

[Outpatient emergency care in pneumology. A method to alleviate pressure of hospital emergency services]. / Atención urgente extrahospitalaria en neumología. Un método para aliviar la presión asistencial de servicios de urgencias hospitalarios.

We analyze the result of using a pneumological rapid-attention facility for diagnosis and immediate treatment of patients with respiratory symptoms arriving at the emergency room of University Hospital Virgen del Rocío in Seville (Spain). In the first six months the outpatient service saw 321 patients (male/female ratio 2.6), most of whom were between 55 and 75 years of age and had never before seen a pneumologist (83.4%). Dyspnea was the most common respiratory symptom named (by 35% of patients), and acute exacerbation of chronic obstructive pulmonary disease was the most usual diagnosis (in 19.1%). Only 21 (7%) were admitted to the hospital. We that creating the outpatient unit effectively met a societal need for rapid diagnosis and treatment of patients with respiratory complaints in the area served by our hospital emergency service.

[Prediction of maximal ventilation during exercise in patients with chronic obstructive pulmonary disease]. / Predicción de la ventilación máxima alcanzada en el esfuerzo en pacientes con enfermedad pulmonar obstructiva crónica.

To analyze the validity of baseline lung function parameters as predictors of maximal exercise ventilation (VEmax) in patients with chronic obstructive pulmonary disease (COPD), we studied 33 stable patients (FEV1 43.6 +/- 16.8%, FEV1/FVC% 48.4 +/- 9.2, FRC 156.8 +/- 32.7% and RV 212 +/- 53.9%). The sample was later divided into 3 groups based on severity of disease (severe, moderate or mild) in order to determine whether ability to predict VEmax increased with airways obstruction (FEV1 26.9 +/- 4.9%, 40.2 +/- 3.5% and 63.9 +/- 10%, respectively). The patients underwent lung function testing at rest and after a progressive stress test, with the maximal reading taken with the subject on a tread mill. We found greater correlation between VEmax and RV, FEV1 and FRC (r = -0.77, 0.75 and -0.74, respectively); the correlation was stronger in patients with severe COPD, in whom FEV1 was under 35% of the predicted value (r = -0.88, 0.753 and -0.83, respectively). Correlation decreased or disappeared with less functional impairment. Prediction of VEmax was more reliable with equations that employed FEV1 accompanied by data reflecting degree of insufflation, RV or FRC (VEmax = 45.2 +/- 8.98 x FEV1 - 5.07 x RV; r2 = 0.72) than with equations based on FEV1 alone (VEmax = 14.79 + 15.03 x FEV1; r2 = 0.56). We therefore conclude that ventilatory limitation during exercise in patients with COPD is better defined by considering parameters related to lung insufflation along with those reflecting degree of expiratory obstruction, given that the former affect the greater or lesser efficacy of muscles under stress.(ABSTRACT TRUNCATED AT 250 WORDS)

[Distribution of pulmonologists and chest surgeons in Spain]. / Distribución de neumólogos y cirujanos torácicos en España.

OBJECTIVE: To study the real situation of respiratory medicine specialists and chest surgeons in the Spanish health service. SUBJECTS AND METHOD: Using the database of the secretary of the Spanish Society of Respiratory Medicine and Chest Surgery (SEPAR) for 1999, we gathered data on 326 Spanish hospitals. We were thus able to ascertain the level of staffing of respiratory medicine and chest surgery departments. The results were expressed as simple percentages showing distribution by age, duties and geographic area. The number of specialists per 100,000 inhabitants in each community was also calculated based on population data provided by the National Statistics Institute for 1997. RESULTS: We studied 1,786 physicians or surgeons (1,245 pneumologists, 185 surgeons and 356 from other specialties). The mean age was 41 9 years for pneumologists, 44 10 years for surgeons and 51 8 years for the others. We observed unequal distribution by geographic area, with a high of 6.66 pneumologists and 0.9 surgeons per 100,000 inhabitants in Asturias and Madrid, respectively and a low of 1.4 pneumologists per 100,000 inhabitants in Murcia and 0 surgeons in Extremadura. CONCLUSIONS: Specialist coverage by pneumologists and chest surgeons is inadequate in many provinces and communities in Spain. The professional market is not saturated, indicating that future specialists can look forward to market demand.

Investigation of tuberculosis contacts in a nonhospital pneumology practice.

The aim of this study was to analyze the results of the tuberculosis contact tracing carried out in an outpatient pneumology setting and to assess its performance with regard to the detection of new cases of tuberculosis and infected contacts. One thousand two hundred and twenty-eight contacts of 302 tuberculosis patients were evaluated in the Tuberculosis Unit of the Dr. Fleming Specialities Center between 1992 and 1996. Contacts were categorized into groups with regard to bacteriological status of the index case (Group A, smear-positive; Group B, culture-positive only; Group C, smear- and culture-negative) and intimacy of exposure to the index case (close or casual). The possible association between the existence of infection or disease and the bacteriological status of the index case and degree of intimacy of exposure was analyzed. There were 582 infected contacts (47.4%) and 42 new cases of tuberculosis (3.4%), six of which were smear-positive. The proportion of infected and diseased contacts was significantly higher for those who had contact with smear-positive patients and those who had close contact with the index case. Chemoprophylaxis was completed in 431 (35.1%) of the contacts evaluated. Systematic investigation of contacts represents an efficient means of discovering new cases of tuberculosis and infection, especially among contacts of smear-positive index cases and among those who are closer to the index case. The administration of appropriate treatment to these contacts will contribute to controlling the transmission of tuberculosis within the community.