José M. Pino

Use of spirometry to predict risk of pneumothorax in CT-guided needle biopsy of the lung.

OBJECTIVE Our goal was to assess the usefulness of spirometry to estimate the risk of pneumothorax in patients undergoing percutaneous needle biopsy with CT guidance for solitary pulmonary nodule (SPN). MATERIALS AND METHODS We studied the results of 51 consecutive percutaneous needle biopsies with CT guidance for SPN obtained between 1988 and 1990. Forty-five men and six women, aged 65 +/- 11 (36-86) years, were included in the study. All biopsies were performed under CT guidance, with 90 mm 25G needles (0.5 mm thickness) fitted into luer-type syringes. The number of needle pass attempts never exceeded three. A spirometry before biopsy was performed in all patients. RESULTS Pneumothorax occurred in only 10 cases (19%). The patients with pneumothorax showed lower lesion size, forced vital capacity (FVC), forced expiratory volume (FEV1), and FEV1/FVC ratio. The contribution of these factors to pneumothorax was analyzed by a logistic regression model. The FEV1 was most strongly associated with the incidence of pneumothorax. We developed an equation for predicting the risk of this complication. CONCLUSION We conclude that decreasing FEV1 is associated with a higher pneumothorax rate.

Value of CT-guided fine needle aspiration in solitary pulmonary nodules with negative fiberoptic bronchoscopy.

The usefulness of fine needle aspiration (FNA) with CT-guidance was evaluated in the diagnosis of solitary pulmonary nodules (SPN) following negative fiberoptic bronchoscopy in 84 patients. The records were analyzed for all patients with SPN who had undergone chest FNA in the years 1988 to 1990, showing previous nondiagnostic fiberoptic bronchoscopy. A final diagnosis was made by biopsy (transbronchial, thoracotomy or necropsy), response to therapy or follow-up of the lesions. The patients had medium-sized lesions, 2.87 ± 1.11 cm, adherent to the pleura in 62%. In the diagnosis of malignancy FNA showed 76% sensitivity, 100% specificity, 100% positive predictive value, 52% negative predictive value and 81% accuracy. These results were correlated with histology in 84% of the cases. One pulmonary hemorrhage, which resolved spontaneously, and 12 cases of pneumothorax, requiring a thoracic tube in 4 patients, were noted.

Lung volume reference values for women and men 65 to 85 years of age.

RATIONALE In elderly subjects, static lung volumes are interpreted using prediction equations derived from primarily younger adult populations. OBJECTIVES To provide reference equations for static lung volumes for European adults 65 to 85 years of age and to compare the predicted values of this sample with those from other studies including middle-aged adults. We compare the lung volumes by plethysmography and helium dilution in elderly subjects. METHODS Reference equations were derived from a randomly selected sample from the general population of 321 healthy never-smoker subjects 65 to 85 years of age. Spirometry and lung volume determinations by plethysmography and multibreath helium equilibration method were performed following the American Thoracic Society/European Respiratory Society recommendations. Reference values and lower and upper limits of normal were derived using a piecewise polynomial model. MEASUREMENTS AND MAIN RESULTS Plethysmography provided higher values than the dilutional method for all lung volumes, with wide limits of agreement. In addition to height, our reference equations confirm the age- and body size dependence of lung volumes in older subjects. Practically all the estimations performed by extrapolating reference equations of middle-aged adults overpredicted the true lung volumes of our healthy elderly volunteers. Middle-aged reference equations classify subjects as being below the total lung capacity lower limit of normal between 17.9 and 62.5% of the women and between 12.5 and 42.2% of the men of the current study. CONCLUSIONS These results underscore the importance of using prediction equations appropriate to the origin, age, and height characteristics of the subjects being studied.

Breathing pattern and central ventilatory drive in mild and moderate generalised myasthenia gravis.

BACKGROUND--Myasthenia gravis is a specific autoimmune disease characterised by weakness and fatigue. Respiratory muscle weakness has been studied using the determination of maximal respiratory pressures, but the response of respiratory centres is not well characterised. This study was undertaken to determine the breathing pattern and the central ventilatory drive in patients with mild and moderate generalised myasthenia gravis. METHODS--Twenty four patients with myasthenia gravis were studied, divided into two groups. Group 1 included 13 subjects (eight women and five men aged 23-64) with mild generalised myasthenia gravis, and group 2 was composed of 15 patients (11 women and four men aged 23-69) with moderate generalised myasthenia gravis. A control group comprised 15 healthy persons with a similar age and sex distribution. Spirometric measurements and maximal respiratory pressures were performed under basal conditions in all subjects, and the rate and depth of breathing and the inspiratory occlusion pressure in the mouth in the first 0.1 second (P0.1) were measured. RESULTS--No difference was detected for parameters of breathing pattern between patients in group 1 and control subjects, although P0.1 was higher in those in group 1. Subjects in group 2 had a lower tidal ventilation, shorter inspiratory time, and a higher frequency with a higher P0.1 than control subjects. CONCLUSIONS--Mild myasthenia gravis causes increased neuromuscular drive with a normal breathing pattern. Moderate myasthenia gravis is characterised by a more rapid shallow breathing pattern.

Prediction Equations for Single-Breath Diffusing Capacity in Subjects Aged 65 to 85 Years

BACKGROUND In senior subjects, diffusing capacity of the lung for carbon monoxide (Dlco) is interpreted using prediction equations derived from primarily younger adult populations. Our objectives were to provide reference equations for single-breath Dlco for a cohort of healthy, never-smoking, white, European adults between 65 and 85 years of age and to compare the predicted values of this sample with those from other studies involving middle-aged adults. METHODS Reference equations were derived from a randomly selected sample from the general population of 431 healthy never smoker subjects aged 65 to 85 years (262 women and 169 men). Spirometry, lung volume determinations by plethysmography, and single-breath Dlco (corrected for hemoglobin) were performed following the American Thoracic Society/European Respiratory Society guidelines. Reference values and lower and upper limits of normal were derived using a piecewise polynomial model. RESULTS In addition to age, our reference equations confirmed the height and body size dependence of Dlco and diffusing capacity for alveolar volume (Dlco/Va) in older subjects. Practically all of the reference values obtained by extrapolating reference equations of middle-aged adults underestimated the true diffusing capacity of the healthy elderly volunteers. Middle-aged reference equations underestimated Dlco by 2.1% to 22.3% in women and 2.8% to 37.8% in men. In addition, Dlco/Va was overestimated up to 18% and 39.8% in women and men, respectively, whereas other equations underestimated Dlco/Va up to 22.2% and 11.9% in women and men, respectively. CONCLUSIONS These results underscore the importance of using prediction equations appropriate to the origin and age characteristics of the subjects being studied.

Relationship Between Exhaled Carbon Monoxide and Airway Hyperresponsiveness in Asthmatic Patients

The study objectives were to analyze the changes in exhaled carbon monoxide (COex) induced by histamine provocation challenge in asthmatic patients and to evaluate the relationship between COex and airway sensitivity and reactivity. Levels of COex were measured in 105 nonsmoking mildly asthmatic subjects before and after histamine provocation challenge. Dose‐response curves were characterized by their sensitivity (PD20) and reactivity. Dose‐response slope (DRS), continuous index of responsiveness (CIR), and bronchial reactivity index (BRI) were determined as reactivity indices. Bronchial challenge was positive for 47 subjects and negative for 58. The COex levels rose significantly after bronchial challenge in the positive response group (4.49 ± 0.4 vs. 5.74 ± 0.57 ppm, p = 0.025) and in the negative response group (2.84 ± 0.25 vs 4.00 ± 0.41 ppm, p = 0.000). An inverse relation between basal COex and PD20 was found (r = − 0.318, p = 0.030). In all subjects, a proportional direct relationship between COex and DRS (r = 0.214, p = 0.015), CIR (r = 0.401, p = 0.000), and BRI (r = 0.208, p = 0.012) was observed. On stepwise multiple linear regression analysis, COex only significantly correlated with CIR (multiple r2 = 0.174, p = 0.000). In conclusion, exhaled CO determination is a noninvasive inflammatory marker of the respiratory tract, which shows an acceptable association with airway hyperresponsiveness.

Tres formas no idiopáticas de bronquiolitis obliterante con neumonía en organización

La bronquiolitis obliterante con neumonia en organizacion es la enfermedad mas importante de los bronquiolos. Se ha descrito una forma idiopatica, de gran trascendencia en el diagnostico diferencial de los casos incipientes de fibrosis pulmonar, y varias formas asociadas con el consumo de farmacos, infecciones, enfermedades del colageno y focal. Se presentan los casos de 3 pacientes con bronquiolitis obliterante con neumonia en organizacion, en relacion con una artritis reumatoide y consumo de sales de oro, con infeccion por el virus de inmunodeficiencia humana y una forma focal asociada a hidatidosis pulmonar.

Noninvasive Measurement of the Maximum Relaxation Rate of Inspiratory Muscles in Patients with Neuromuscular Disorders

Background: Slowing of inspiratory muscle relaxation has been used as an index for inspiratory muscle fatigue. However, maximum relaxation rate measured from oesophageal pressure traces after maximum sniff (P_oes MRR) has limited clinical usefulness because it requires an oesophageal balloon catheter system. Objectives: It was the aim of this study to establish whether, in neuromuscular patients, maximum relaxation rate assessed from sniff nasal pressure (P_nasal MRR) reflects oesophageal MRR and the tension-time index of the diaphragm (TT_di). Methods: Twenty patients with neuromuscular disease and 10 healthy subjects were studied. P_oes and transdiaphragmatic pressure were measured while P_nasal was recorded with a balloon advanced through the nose into the nasopharynx. Maximum P_oes, transdiaphragmatic pressure and P_nasal were simultaneously measured while the patients performed maximal sniffs. The MRR (% pressure fall/10 ms) for each sniff, the TT_di and the tension-time index of respiratory muscles were determined. Results: Neuromuscular patients showed higher TT_di, lower P_oes MRR and lower P_nasal MRR than the control group. In patients with neuromuscular disease, the correlation coefficient of P_nasal MRR and P_oes MRR was 0.985 (p < 0.001). Regression analysis showed that P_oes MRR = –1.101 + 1.113·P_nasal MRR (r² = 0.929, standard error of the estimate = 0.208). Indeed, P_nasal MRR was negatively correlated with TT_di (r = –0.914, p < 0.001) and the tension-time index of respiratory muscles (r = –0.732, p < 0.001). In the neuromuscular group, the mean difference between P_nasal MRR and P_oes MRR was 0.286 ± 0.217%/10 ms. Conclusions: P_nasal MRR obtained from a maximal sniff accurately reflects P_oes MRR and TT_di in patients with neuromuscular disorders.

Nocturnal Arterial Oxygen Desaturation Secondary to a Sphenoidal Meningioma

We report the case of a nonobese and nonsmoking 51-year-old man with nocturnal arterial oxygen desaturation that returned to normal after sphenoidal meningioma resection. He presented an important daytime hypersomnia and episodes of nocturnal apnea, without snoring. His arterial blood gases, mechanical properties of the respiratory system pulmonary diffusing capacity and chemosensitivity were normal. The most frequent causes of nocturnal hypoxemia are examined.

Formas etiológicas menos frecuentes del tromboembolismo pulmonar

El tromboeembolismo pulmonar (TEP) es un proceso patologico que puede ser debido a diversas causas. De ellas, la mas conocida es la trombosis venosa profunda. Sin embargo, tambien se ha asociado a otros factores etiologicos menos frecuentes, como los trastornos de la coagulacion. A partir del caso de un varon que con TEP de repeticion por un estado de hipercoagulacion, hacemos una revision de etiologias menos tipicas de TEP.