[Muscle relaxants in the morphometric study of the respiratory muscles in human beings]. / Relajantes musculares en el estudio morfométrico de los músculos respiratorios en seres humanos.

The morphological examination of respiratory muscle can be affected by muscular contraction following biopsy. Most morphometric studies of respiratory muscles, however, have been carried out without taking into account this factor, the effect of which can be reduced by using relaxants when taking samples. Objective. To examine the effect of using a relaxant in the morphometric analysis of muscle fibers. We examined 31 muscle samples from 7 patients. Immediately after removal, each pipe was divided in half. One was placed in an isotonic physiological solution and the other in a solution of curare 0.02%. Later, both samples were processed for morphometric study with ATP-ase, NADTH and PAS tincture. Morphological data recorded for the different types of fibers included measurement of minimum diameter (Dmin), atrophy and hypertrophy indices (AI and HI) and heterogeneity of distribution (SDDmin). The Dmin was smaller in fibers transported in a curare solution than in those transported in physiological solution (67 +/- 2 microns vs. 71 +/- microns, p < 0.05). The same was true of SDDmin (13 +/- 3 vs. 12 +/- 3, p < 0.05), HI (300 +/- 88 vs. 457 +/- 107, p < 0.05). Likewise, we found a similar direct correlation between size of fibers processed with physiological solution and those processed in curare (Dmin, r = 0.731, p < 0.001; HI, r = 0.827, p < 0.001; SDDmin, r = 0.636, p < 0.0001). The use of relaxants in processing muscle samples prevents contraction and should be used systematically in the morphological analysis of muscle fibers.(ABSTRACT TRUNCATED AT 250 WORDS)

[The characteristics of the mechanical activity of the respiratory muscles during the diaphragmatic respiration technic]. / Características de la actividad mecánica de los músculos respiratorios durante la técnica de "respiración diafragmática".

UNLABELLED: Noteworthy among breathing training techniques is so-called diaphragmatic breathing. In spite of the technique's name, however, little is known of the functional characteristics of this ventilatory method. OBJECTIVE: To asses the mechanics of respiratory muscles, particularly diaphragm muscles, during diaphragmatic breathing in patients with severe chronic obstructive pulmonary disease (COPD). METHODS: Ventilatory pattern and respiratory pressures (abdominal [Pga], intrathoracic [Pes] and transdiaphragmatic [Pdi]) were studied in 10 patients with severe COPD in stable phase (age 69 +/- 6 years, FEV1 33 +/- 12% ref) at baseline and during deep breathing with spontaneous muscle recruitment (SMR) and during breathing training. Measurements were taken with the patient seated and in supine decubitus position. RESULTS: In seated position ventilatory pattern was similar with SMR and during breathing training. Mean Pdi during airflow, however, was greater during breathing training than with SMR (34.8 +/- 8.0 and 29.3 +/- 9.3 cmH2O, respectively, p < 0.05) for similar levels of Pes. Mechanical effectiveness of the diaphragm expressed as Vt/Pdi) was less during breathing training, however (36.1 +/- 10.4 and 49.5 +/- 15.8 cc/cmH2O, p < 0.05), with no changes in overall efficacy of respiratory muscles (Vt/Pes). In supine decubitus position, ventilatory patterns of SMR and breathing training were similar, although Vt and T1 were slightly higher in the latter (1,065 +/- 305 vs. 1,211 +/- 314 cc, p < 0.01; and 2.76 +/- 1.32 vs. 3.07 +/- 1.23 sec, p < 0.05). Pdi was also higher during breathing training (29.7 +/- 10.2 and 38.0 +/- 10.5 cmH2O, p < 0.05), although accompanied in this case by a higher Pes (21.2 +/- 7.5 to 26.4 +/- 8.4 cmH2O, p < 0.005). In supine decubitus position, the effectiveness of both diaphragm muscles and respiratory muscles overall was similar for both ventilatory modes. CONCLUSIONS: Breathing training truly involves greater use of the diaphragm, both in seated and supine decubitus positions. Breathing training does not provide greater ventilatory efficacy than SMR, however, in COPD patients.

[Diaphragmatic function during exercise in patients with severe COPD]. / Función diafragmática durante el ejercicio en pacientes con EPOC severa.

UNLABELLED: Ventilatory requirements increase during exercise. The respiratory muscles of patients with chronic obstructive pulmonary disease (COPD) are at a particular disadvantage when dealing with such increased demand. The objective of this study was to evaluate the changes in respiratory muscles brought on by exercise in such patients. METHODS: Twelve patients with severe CFOPD (FEV1 < 50% ref., 63 +/- 7 years) were enrolled. Breathing patterns and esophageal (Pes and transdiaphragmatic (Pdi) pressures and SaO2 were measured during submaximal exercise/Ecsbmax, 60% of the maximum tolerated load). A sniff maneuver was performed with the patients breathing ambient air with added oxygen to achieve 99% SaO2. We also measured level of FRC by inductive plethysmograph in a subgroup of five patients. RESULTS: During EXsbmáx, SaO2 decreased (from 95.0 +/- 2.1 to 92.3 +/- 4.0%; p < 0.01); Vt increased (717 +/- 199 to 990 +/- 297 cc, p < 0.01), as did respiratory rate (RR, 17 +/- 6 a 28 +/- 9; p < 0.01). Pes and Pdi were greater at Vt, changing from -12.4 +/- 4.8 to -27.0 +/- 10.1 and 16.6 +/- 6.1 to 30.4 +/- 12.4 cmH2O, respectively (p < 0.01 in both cases), whereas no significant changes were observed for maximal effort (Pesmax, -61.4 +/- 16.5 cersus -65.9 +/- 15.2 cmH2O; Pdimac 89.7 +/- 26.1 versus 81.7 +/- 35.7 cmH2O). Used as a global measure, Pdi/Pdimáx worsened (0.21 +/- 0.12 a 0.42 +/- 0.20; p < 0.01), as dud the diaphragm tension-time (TTdi; 0.07 +/- 0.04 to 0.15 +/- 0.06, p < 0.01). Intrinsic positive end-expiratory pressure (PEEPi) increased an estimated 2.7 +/- 2.1 to 9.4 +/- 5.8 cmH2O (p < 0.001), while FRC (delta 357 +/- 274 ml). Durante el EXsbmáx with oxygen supplementation, SaO2 did not decrease. However supplementation, though Ti/TTOT and maximal pressures remained unchanged. CONCLUSIONS: Respiratory muscle function changes induced by Exsbmáx seem to relate mainly to a worsening of system mechanics.

[Capillary density and respiratory function in the external intercostal muscle]. / Densidad capilar y función respiratoria en el músculo intercostal externo.

UNLABELLED: Changes in lung function have been related to adaptive structural modifications in respiratory muscles. OBJECTIVE: To evaluate the capillary density (Dcap) of the external intercostal muscle in patients with chronic obstructive pulmonary disease (COPD), and its possible relation to respiratory function. METHODS: Forty-two individuals (61 +/- 9 years old) underwent conventional lung function testing and evaluation of respiratory muscles (maximum pressures at rest and a tolerance test using Martyn's technique). The sample included 10 subjects with normal lung function and 32 COPD patients (FEV1 between 13 and 78% of reference), in stable phase and with no respiratory insufficiency (PaO2 > 60 mmHg). A local biopsy of the external intercostal muscle was taken from all subjects at the fifth intercostal space (anterior axillary [correction of axile]) on the non-dominant side. The sample was processed for morphometry and fiber typing with ATPase staining and for quantifying capillarity with Gomori's trichrome staining. RESULTS: The mean diameter was 61 +/- 10 micrograms, with type I fibers predominating (56 +/- 11%). Dcap was 2.8 +/- 0.6 capillaries/fiber (equivalent to 1.02 +/- 0.37 capillaries/mm2 of fibrillary surface). The number of capillaries/fiber was significantly higher in patients with severe COPD (FEV1 < 50% ref) than in controls (3.0 +/- 0.6 versus 2.3 +/- 0.5, p < 0.01) and was inversely related to FEV1 (r = -0.395, p < 0.01). Muscle capillarity was unrelated to other function variables, including markers of respiratory muscle function and gas exchange. CONCLUSION: The structural remodelling of external intercostal muscles in COPD patients also includes an increase in density of interfibrillary capillaries. This increase is proportional to the severity of obstruction and probably reflects an adaptive phenomenon.

[Usefulness of respiratory endoscopy in patients with severe rhonchi and/or sleep apnea syndrome]. / Utilidad de la endoscopia respiratoria en pacientes con roncopatía acusada y/o síndrome de apneas del sueño.

BACKGROUND: Obstruction of the upper respiratory tract is the most common cause of the sleep apnea syndrome (SAS). Different methods have been used to localize this obstruction and give the appropriate treatment. The aim of this study was to evaluate the usefulness of respiratory endoscopy performed during arousal to identify the site and cause of the obstruction in patients with severe rhoncopathy and/or SAS. METHODS: Sixty-eight patients with acute rhoncopathy were included in the study with 36 also fulfilling polysomnographic criteria of SAS (36%). The endoscopy was performed via the upper respiratory tract with inspiratory collapse at each level being evaluated in both easy respiration and during the Müller manoeuver. RESULTS: The site and cause of the obstruction was identified in 61 patients (90%, CI 95%, 79.9 +/- 95.8). In most cases the Müller manoeuver best demonstrated the collapse. The predominant obstruction was in the nasopharyngeal region (72%, mainly associated to changes in soft palate), followed by obstruction in the oropharyngeal region at the base of the tongue (29%). Multiple localization of the obstruction was observed in 19 patients. CONCLUSIONS: Endoscopy performed during arousal may allow the identification of the site and cause of obstruction in most of the patients with rhoncopathy and sleep apnea syndrome, thus aiding in the selecting the most adequate treatment for the patient.

[Neurofibromatosis in children. Our experience]. / Neurofibromatosis en niños. Nuestra experiencia.

INTRODUCTION: Neurofibromatosis type 1 (NF1) is an autosomal dominant disorder with a high index of spontaneous mutations and extremely varied and unpredictable clinical manifestations. It is diagnosed by the existence of certain clinical criteria which cannot appear until adulthood. PATIENTS AND METHODS: The clinical histories of the confirmed or possible cases of neurofibromatosis (NF) in the neuropaediatric databases at the Hospital Miguel Servet in Zaragoza and at the Hospital General in Guadalajara were analysed retrospectively. RESULTS: Cases were distributed in 46 NF1, six compatible with NF1, 11 with just marks, five with marks and a family history of marks, and two cases of segmentary NF. Among the confirmed cases of NF1, the following alterations were found: optic glioma (OG) in eight, and one of them developed a glioblastoma multiforme, multiple radicular neurofibromas in one, mental retardation in one and learning disorders in 13 of the 29 school aged children, afebrile seizures in three, precocious puberty in two and scoliosis in nine. Brain areas with hypersignals were found in 71% of the cases submitted to magnetic resonance imaging (MRI) (20 out of 28), including seven of the eight patients suffering from OG. DISCUSSION: Our case mix, like all the others, exemplifies the clinical heterogeneity and unpredictable progression of children with NF1 or who are suspected of suffering from it. We followed the most widely used method of clinical and ophthalmological control, and complementary examinations were performed according to the clinical features. If neuroimaging is used, it must be MRI.

Pneumatoceles and pneumothorax after Pneumocystis carinii pneumonia.

Pneumocystis carinii pneumonia (PCP) is common in patients with AIDS. The usual chest X-ray pattern is a diffuse interstitial pulmonary infiltrate. Nevertheless, unusual roentgenographic forms can appear. A patient with PCP that resulted in pneumatoceles and a further pneumothorax is described.

Effects of interpleural bupivacaine on respiratory muscle strength and pulmonary function.

BACKGROUND: Several reports suggest that interpleural local anesthetics may have deleterious effects on respiratory function. The current study investigated the effects of interpleural bupivacaine on human respiratory muscles and lung function. METHODS: Thirteen patients (55 +/- 4 yr old) with normal respiratory function and scheduled for cholecystectomy entered the study before surgery. Respiratory parameters were compared before and after the interpleural administration of 20 ml 0.5% bupivacaine plus 1:200,000 epinephrine while patients were supine; we evaluated breathing pattern, dynamic and static lung volumes, airway conductance, maximal inspiratory pressures (at the mouth; at the esophagus [Pessniff]; at the abdomen [Pgasniff]; and transdiaphragmatic [Pdisniff]), functional reserve (tension-time index) of the diaphragm, and maximal expiratory pressures (at the mouth; at the esophagus [Pescough]; and at the abdomen [Pgacough]). Hemoglobin oxygen saturation by pulse oximetry, heart rate, and mean arterial pressure were continuously monitored. RESULTS: Respiratory rate (15 +/- 1 to 19 +/- 1 breaths/min; P < 0.01) and heart rate (78 +/- 3 to 83 +/- 3 beats/min; P < 0.01) were slightly increased. Dynamic and static lung volumes, airway conductance, hemoglobin saturation, and the remaining breathing pattern parameters were unchanged. Regarding respiratory muscles, maximal inspiratory pressure at the mouth, Pessniff, and tension-time index of the diaphragm did not change. Pdisniff decreased slightly (102 +/- 10 to 92 +/- 10 cmH2O; P < 0.05) because of a change in Pgasniff (24.2 +/- 7.4 to 18.4 +/- 6.8 cmH2O; P < 0.05). Maximal expiratory pressure at the mouth remained unaltered, but Pgacough decreased (108 +/- 10 to 92 +/- 8 cmH2O; P < 0.01), and Pescough showed a trend to decrease (92 +/- 13 to 78 +/- 10 cmH2O; P = 0.074). CONCLUSIONS: In our experimental conditions, interpleural bupivacaine did not significantly change lung function or inspiratory muscle strength but induced a slight decrease in abdominal muscle strength. Although this effect was minimal, its clinical relevance needs to be evaluated further in patients with impaired respiratory function.

Activity of latissimus dorsi muscle during inspiratory threshold loads.

The ability of the latissimus dorsi muscle (LD) to participate as an accessory inspiratory muscle has been the subject of controversy. Electromyographic (EGM) activity of LD was evaluated in 11 healthy subjects (aged 30 +/- 2 yrs; forced expiratory volume in one second (FEV1) 106 +/- 5% predicted; maximal inspiratory pressure (Pmax), 120 +/- 6 cmH2O) under different breathing conditions. The ipsilateral biceps brachii was chosen as the control muscle. The EMG was recorded from surface electrodes, but needle electrodes were also used for LD evaluation in a subset of three subjects. The EMG signal from both muscles was recorded simultaneously, rectified and integrated, with subtraction of the electrocardiographic signal. Situations evaluated were: 1) maximal voluntary contraction (MVC); 2) apnoea; and 3) breathing under progressive inspiratory threshold loads (20-100% Pmax, at 20% intervals). A close relationship was evident between LD recordings from surface and needle electrodes (r = 0.975). Activity of LD at baseline was 1.8 +/- 0.4% MVC, and showed a phasic increase during inspiration under loads. This change had a linear tendency and was significant for loads corresponding to 40, 60, 80 and 100% of Pmax when compared to the control muscle. At this latter level, LD activity was equivalent to 32 +/- 5% MVC (range 11-61%), whereas mean activity of the control muscle was less than 7.5% MVC.(ABSTRACT TRUNCATED AT 250 WORDS)

Methacholine induced headache.

A lung function technician developed episodes of headache, probably related to the use of methacholine. The headache disappeared with breathing 100% oxygen. Cholinergic agents are known to induce headaches but the mechanism remains unclear. Vascular factors could be implicated.

Simplified exercise test for the initial differential diagnosis of Pneumocystis carinii pneumonia in HIV antibody positive patients.

BACKGROUND: This study was designed to evaluate the usefulness of a simplified exercise test in the differential diagnosis of Pneumocystis carinii pneumonia (PCP). METHODS: Forty five subjects with antibodies against the human immunodeficiency virus (HIV) and pneumonia were included and divided into two groups: those with PCP and those with "other pneumonias" (non-PCP). The test involved pedalling for two minutes on a stretcher bed and was considered positive if SaO2 decreased by at least 3%. RESULTS: During the exercise the mean(SE) SaO2 fell in patients with PCP from 88(4)% to 84(3)%, p < 0.01, whilst it improved slightly in subjects with non-PCP from 91(1)% to 93(3)%, p < 0.05. Sensitivity was 77% and specificity 91%. CONCLUSIONS: This simple test seems potentially useful for the initial investigation of HIV antibody positive patients with pneumonia.

Probable pentamidine-induced acute pancreatitis.

OBJECTIVE: To report a case of probable pentamidine-induced acute pancreatitis. CASE SUMMARY: A patient was hospitalized because of fever, dyspnea, and productive cough. Chest X-ray revealed diffuse alveolar infiltrates, and the examination of bronchoalveolar lavage demonstrated the presence of Pneumocystis carinii. Intravenous cotrimoxazole was administered but the patient's condition did not improve. As secondary leukopenia appeared, the treatment was changed to pentamidine isethionate 4 mg/kg/d i.v. On day 5 of this new therapy, the patient experienced abdominal pain, and both blood and urine amylase concentrations raised to 330 U/L and 3960 U/L, respectively. The patient died 48 hours later, and signs of acute pancreatitis were observed in necropsy. DISCUSSION: With reference to a classical method for estimating the probability of adverse drug reactions, a probable relationship between pentamidine therapy and acute pancreatitis was found in this patient. Furthermore, no alternative causes of pancreatitis were present. CONCLUSIONS: It is likely that pentamidine administration in our patient resulted in an acute episode of pancreatitis. Serum and urine amylase concentrations should be monitored in patients receiving this drug.

Validity and reliability of the St George's Respiratory Questionnaire after adaptation to a different language and culture: the Spanish example.

We describe the adaptation into Spanish of the St George's Respiratory Questionnaire (SGRQ), a self-administered questionnaire developed by Jones et al. (1991) covering three domains of health in airways disease patients: symptoms, activity and impacts. For the adaptation, the forward and back-translation method by bilinguals was used, together with professional committee and lay panel. Once tested for feasibility and comprehension, 318 male chronic obstructive pulmonary disease (COPD) patients with a wide range of disease severity completed the Spanish version of the SGRQ. The clinical status of the patients was evaluated concurrently with the measurement of health status. Lung function was assessed in the 2 months before or after the questionnaire administration. The Spanish version of the SGRQ was acceptable and easy to understand. Cronbach's alpha reliability coefficient was 0.94 for the overall scale and 0.72 for "Symptoms", 0.89 for "Activity", and 0.89 for "Impacts" subscales. Correlation coefficients between the overall score and dyspnoea and % forced expiratory volume in one second (FEV1) were 0.59 and -0.45, respectively, and these correlations were higher than those observed between the clinical variables and the Nottingham Health Profile, a generic measure of health-related quality of life. Results of the study suggest that the Spanish version of the SGRQ is conceptually equivalent to the original, and similarly reliable and valid. Although further studies should complete the adaptation work, results suggest that the SGRQ may already be used in Spain and in international studies involving Spanish respiratory patients. According to the present approach, it appears to be feasible to adapt a specific questionnaire on health-related quality of life in respiratory disease to another language and culture.

Chronic obstructive pulmonary disease stage and health-related quality of life. The Quality of Life of Chronic Obstructive Pulmonary Disease Study Group.

BACKGROUND: The American Thoracic Society recently recommended that chronic obstructive pulmonary disease be staged on the basis of the percentage of predicted FEV1. OBJECTIVE: To examine 1) the relation between the american Thoracic Society system for staging chronic obstructive pulmonary disease and health-related quality of life and 2) the effect of self-reported comorbid conditions on health-related quality of life. DESIGN: Cross-sectional study. SETTING: Outpatient clinics of respiratory departments of four hospitals and one primary health care center in spain. PATIENTS: 321 consecutive male patients with chronic obstructive pulmonary disease. MEASUREMENTS: Functional respiratory impairment, FEV1, respiratory symptoms, and health-related quality of life. Respiratory symptoms and health-related quality of life were measured by using the Spanish version of the St. George's Respiratory Questionnaire and the Nottingham Health Profile. RESULTS: Patient scores on the St. George's Respiratory Questionnaire were moderately to strongly associated with disease staging (r = 0.27 to 0.51). Compared with reference values, values for health-related quality of life for patients with stage I disease were substantially higher on the St. George's Respiratory Questionnaire (6 and 34; p < 0.001) and values for impairment were significantly greater in stage 1 patients with comorbid conditions (19 and 36; P = 0.001). At least one concomitant chronic condition was found in 84% of study patients. Comorbid conditions only partly influenced the observed pattern of deterioration of health-related quality of life with worsening stages of disease. CONCLUSION: Staging criteria for chronic obstructive pulmonary disease based on percentage of predicted FEV1 separated groups of patients with varying degrees of impairment in health-related quality of life. Contrary to expectations, even patients with mild disease showed substantially compromised health-related quality of life. Comorbid conditions influenced the relation between chronic obstructive pulmonary disease and health-related quality of life.