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J Gea

Publications and source records attributed to J Gea.

At least 37 records · Page 2Linked to original sources
PubMed1999

[Diaphragmatic function during exercise in patients with severe COPD].

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.

Data Interpretation, Statistical↗
PubMed1999

Subcellular adaptation of the human diaphragm in chronic obstructive pulmonary disease.

Pulmonary hyperinflation impairs the function of the diaphragm in patients with chronic obstructive pulmonary disease (COPD). However, it has been recently demonstrated that the muscle can counterbalance this deleterious effect, remodelling its structure (i.e. changing the proportion of different types of fibres). The aim of this study was to investigate whether the functional impairment present in COPD patients can be associated with structural subcellular changes of the diaphragm. Twenty individuals (60+/-9 yrs, 11 COPD patients and 9 subjects with normal spirometry) undergoing thoracotomy were included. Nutritional status and respiratory function were evaluated prior to surgery. Then, small samples of the costal diaphragm were obtained and processed for electron microscopy analysis. COPD patients showed a mean forced expiratory volume in one second (FEV1) of 60+/-9% predicted, a higher concentration of mitochondria (n(mit)) in their diaphragm than controls (0.62+/-0.16 versus 0.46+/-0.16 mitochondrial transections (mt) x microm(-2), p<0.05). On the other hand, subjects with air trapping (residual volume (RV)/total lung capacity (TLC) >37%) disclosed not only a higher n(mit) (0.63+/-0.17 versus 0.43+/-0.07 mt x microm(-2), p<0.05) but shorter sarcomeres (L(sar)) than subjects without this functional abnormality (2.08+/-0.16 to 2.27+/-0.15 microm, p<0.05). Glycogen stores were similar in COPD and controls. The severity of airways obstruction (i.e. FEV1) was associated with n(mit) (r=-0.555, p=0.01), while the amount of air trapping (i.e. RV/TLC) was found to correlate with both n(mit) (r=0.631, p=0.005) and L(sar) (r=-0.526, p<0.05). Finally, maximal inspiratory pressure (PI,max) inversely correlated with n(mit) (r=-0.547, p=0.01). In conclusion, impairment in lung function occurring in patients with chronic obstructive pulmonary disease is associated with subcellular changes in their diaphragm, namely a shortening in the length of sarcomeres and an increase in the concentration of mitochondria. These changes form a part of muscle remodelling, probably contributing to a better functional muscle behaviour.

Adaptation, Physiological↗
PubMed1998

[Fiber morphometry of the external intercostal muscle. Comparison of dominant and nondominant sides in patients with severe COPD].

The general morphometric characteristics of the external intercostal muscle (EIM) of patients with chronic respiratory disease have been well described. Because this muscle is highly accessible, it can provide an ideal model for longitudinal studies using consecutive biopsies of both sides. Whether or not the EIM fiber phenotype is homogeneous on dominant (D) and non dominant (ND) sides is unknown, however. To evaluate possible structural differences in right and left EIM in patients with COPD, eight patients (63 +/- 7 years of age) were enrolled. Lung function, respiratory muscle power, general muscle power and nutritional state were evaluated. Biopsies of the fifth EIM were taken from both sides. Specimens were processed in parallel manner to determine conventional morphometry (hematoxylin-eosin staining), including minimum diameter (Dm) and fiber area (Ar) in cross sections. Fibers were typed by ATPase (at pH 4.2, 4.6 and 9.4) and NADH-TR staining. Nutrition was normal in all patients. All patients had severe COPD (FEV1 27 +/- 7% of reference, limits 13 to 38% of reference) with air entrapment (RV 163 +/- 36% of reference, limits 181 to 276% of reference). None of the patients showed respiratory insufficiency at rest (PaO2 72 +/- 7 mmHg). Peripheral musculoskeletal power measured by manual dynamometer showed no significant right-left differences: D 29 +/- 2 and ND 28 +/- 3 dynes. Morphometric study of 16 muscle specimens showed no significant differences between fiber size on D and ND sides. DmD was 47 +/- 10 microns and ArD, was 2,595 +/- 1,249 microns2. DmD was 49 +/- 9 microns and ArD was 2,636 +/- 953 microns2. Likewise, no significant differences were found between D and ND fiber types: type ID 51 +/- 4% and type IID 49 +/- 5% versus type IND 52 +/- 4% and type IIND 48 +/- 4%. EIM on N and ND sides is homogeneous at the fifth intercostal space. This finding, along with the scarcely invasive nature of the technique for collecting specimens leads us to suggest that longitudinal studies might be performed on the structural effects of various pharmacological or physical treatments followed by COPD patients

Aged↗
PubMed1998

[Cellular homogeneity in diverse portions of the diaphragm].

The diaphragm is the main inspiratory muscle. It is composed of two parts, the costal and crural, with both anatomical and functional differences. The general morphometric characteristics of the diaphragm have been described in various species but homogeneity throughout the muscle has not been adequately studied. The aim of this study was to evaluate the fiber phenotype of various parts of the diaphragm. The entire diaphragm muscles of five New Zealand rabbits were removed and each was divided into quarters. The specimens were processed for morphometry (hematoxyllineosin stains, NADH-TR and ATPase at pH levels of 4.2, 4.6 and 9.4). For each portion we measured percent and size of fibers, expressing the latter as minimum diameter (Dm), measured area (Ar) and calculated area (Ac). Left and right diaphragm hemispheres (20 portions examined) were similar for fiber percentages and sizes. For left and right halves, respectively 50 +/- 2 and 51 +/- 4% of fibers were type I; type I Dm measurements were 38 +/- 5 and 41 +/- 4 microns; type I Ar values were 1798 +/- 481 and 2030 +/- 390 micron 2; type I Ac values were 1181 +/- 360 and 1321 +/- 382 micron 2; type II Dm values were 46 +/- 4 and 46 +/- 5 microns; type II Ar values were 2466 +/- 388 micron 2 and 2539 +/- 456 micron 2; type II Ac data were 1642 +/- 255 and 1655 +/- 382 micron 2. We likewise found no differences between costal and crural portions of the muscle (n = 20). For costal and crural portions, respectively, 50 +/- 3 and 50 +/- 2% of fibers were type I; type I Dm sizes were 39 +/- 5 and 40 +/- 4 microns; type I Ar measurements were 1859 +/- 521 and 1964 +/- 365 micron 2; type I Ac figures were 1231 +/- 317 and 1266 +/- 288 micron 2; type II Dm were 47 +/- 4 and 44 +/- 3 microns; type II Ar were 2563 +/- 481 and 2430 +/- 331 micron 2; type II Ac were 1729 +/- 373 and 1557 +/- 212 micron 2. Type II fibers, however, were somewhat larger than type I fibers in all portions (p = 0.001). New Zealand rabbit diaphragm muscle has similar percentages of slow and rapid contraction fibers. The size is not different from that observed in other species of mammals of similar size. Fiber type proportions are similar throughout the muscle, with more type II fibers present in all areas. The morphometric characters, therefore, suggest an homogeneous throughout the diaphragm, suggesting homogeneous response of the muscle to usual loads, and also suggesting the possibility of proposing longitudinal morphometric studies using this species as a model.

Animals↗
PubMed1998

Structure and function relationships of the respiratory muscles.

Potential relationships between the structure of the diaphragm and external intercostals and several indices of respiratory muscle function, lung function and nutrition in 27 patients (61+/-10 yrs of age) subjected to thoracotomy as a result of a lung neoplasm have been investigated. Prior to surgery the nutritional status of the patients was assessed and lung function (spirometry, lung volumes, transfer factor of the lungs for carbon monoxide, arterial blood gases) and respiratory muscle function (maximal inspiratory pressure (MIP) and diaphragmatic function were measured). Biopsies of the diaphragm (and external intercostals) were obtained during surgery. On average, patients showed mild airflow limitation (forced expiratory volume in one second (FEV1), 70+/-14% of predicted value, FEV1/forced vital capacity (FVC), 70+/-9%) with some air trapping (residual volume (RV), 139+/-50% pred) and normal gas exchange (arterial oxygen tension (Pa,O2), 11.3+/-1.33 kPa (85+/-10 mmHg)) and arterial carbon dioxide tension (Pa,CO2) 5.4+/-0.5 kPa (40.6+/-4 mmHg). MIP was 77+/-25% pred; maximal transdiaphragmatic pressure was 90+/-27 cmH2O. Most morphometric measurements of the diaphragm and external intercostals were within the range of values reported previously in other skeletal muscles. The size of the fibres of these two respiratory muscles was positively related (p<0.05) to MIP (% pred). There were no significant relationships between the structure of both muscles and nutritional status or any index of lung function. In conclusion, in the population studied, the fibre size of the diaphragm and external intercostals appears to relate to their ability to generate force.

Diaphragm↗
PubMed1997

[The diaphragm].

Explore the source record for details and available documents.

Diaphragm↗
PubMed1997

Diaphragm muscle fiber injury after inspiratory resistive breathing.

Five awake previously tracheotomized mongrel dogs were challenged with inspiratory resistive breathing (IRB). The mean peak tracheal pressure = -35.4 +/- 1.1 cmH2O, ETCO2 = 39.8 +/- 1.5 mmHg was sustained for 2 h/d over 4 consecutive d. On the fourth day, following IRB, the dogs were placed under general anaesthesia, and the diaphragm was perfused via the internal mammary artery with a low molecular weight fluorescent tracer (Procion orange, FW = 631), to which normal muscle fibers are impermeable. Muscle fiber membrane damage was identified on tissue sections by using fluorescent microscopy showing the presence of the tracer in the cytoplasm. Four dogs undergoing the same protocol (except IRB) served as control. The dye was seen in 7.6 +/- 2.6% and in 0.3 +/- 0.1% of fibers in the IRB and control groups, respectively (p < 0.05). Via ATPase staining, it was found that fibers of type I were predominantly affected as compared to type II (p < 0.05). In addition, an increased area fraction of fibers demonstrating sarcomere disruption was found after IRB (2.4 +/- 0.5%) compared to pre-IRB (0.4 +/- 0.1%; p < 0.05). We conclude that resistive breathing of a magnitude similar to that seen in some respiratory diseases, or used in respiratory muscle training programs induces muscle membrane and sarcomere injury.

Animals↗
PubMed1995

[Muscle relaxants in the morphometric study of the respiratory muscles in human beings].

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)

Biopsy↗
PubMed1995

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.

Adult↗
PubMed1995

Structure of the latissimus dorsi muscle and respiratory function.

The aim of this study was to evaluate whether respiratory function influences the structure of the latissimus dorsi muscle (LD). Twelve patients (58 +/- 10 yr) undergoing thoracotomy were studied. Lung and respiratory muscle function were evaluated before surgery. Patients showed a forced expired volume in 1 s (FEV1) of 67 +/- 16% of the reference value, an FEV1-forced vital capacity ratio of 69 +/- 9%, a maximal inspiratory pressure of 101 +/- 21% of the reference value, and a tension-time index of the diaphragm (TTdi) of 0.04 +/- 0.02. When patients were exposed to 8% CO2 breathing, TTdi increased to 0.06 +/- 0.03 (P < 0.05). The structural analysis of LD showed that 51 +/- 5% of the fibers were type I. The diameter was 56 +/- 9 microns for type I fibers and 61 +/- 9 microns for type II fibers, whereas the hypertrophy factor was 87 +/- 94 and 172 +/- 208 for type I and II fibers, respectively. Interestingly, the histogram distribution of the LD fibers was unimodal in two of the three individuals with normal lung function and bimodal (additional mode of hypertrophic fibers) in seven of the nine patients with chronic obstructive pulmonary disease. An inverse relationship was found between the %FEV1-forced vital capacity ratio and both the diameter of the fibers (type I: r = -0.773, P < 0.005; type II: r = -0.590, P < 0.05) and the hypertrophy factors (type I: r = -0.647, P < 0.05; type II: r = -0.575, P = 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1995

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)

Adult↗
PubMed1994

[Usefulness of respiratory endoscopy in patients with severe rhonchi and/or sleep apnea syndrome].

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.

Endoscopy↗
PubMed1994

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.

Adult↗
PubMed1994

[Neutrophilia in the bronchoalveolar lavage of patients with AIDS and Pneumocystis carinii pneumonia. Reflections on its prognostic value in the Spanish setting].

The prognostic value of neutrophilia (> 5%) in bronchoalveolar lavage (BAL) in our context is studied in 21 patients with AIDS and Pneumocystis carinii pneumonia. Neutrophilia does not seem to be a good prognostic indicator in our context. We have found this condition, with a mean of 6 +/- 4%, in only 33% of our sample. The sensitivity of this parameter with respect to risk of death was very low (25%), while specificity was moderate (65%). In contrast with what has been reported in studies done with Anglo-Saxon populations, neutrophilia in BAL is probably of little prognostic use in our context. This may be due to various factors, among them the type of population (most being intravenous drug users) and the therapeutic protocol (early empirical treatment).

AIDS-Related Opportunistic Infections↗
PubMed1993

Diaphragmatic activity induced by cortical stimulation: surface versus esophageal electrodes.

Evoked responses of the diaphragm can be induced by magnetic cortical stimulation and recorded by either surface or esophageal electrodes. The former recording system is tolerated better by the patient but has potential problems with the specificity of the diaphragmatic signal. This study compares the responses of the diaphragm to cortical stimulation that were recorded simultaneously with surface and esophageal electrodes on seven patients (61 +/- 4 yr) with chronic obstructive pulmonary diseases. Stimuli were delivered in three ventilatory conditions: at baseline, during deep breathing, and during voluntary panting. No differences were observed between results recorded by surface and esophageal electrodes [amplitude of the compound motor of the action potential (CMAP), 0.8 +/- 0.1 vs. 0.8 +/- 0.1 mV, NS; latency, 13.1 +/- 0.4 vs. 12.6 +/- 0.5 ms, NS]. In addition, significant correlations were found (CMAP, r = 0.77, P < 0.001; latency, r = 0.71, P = 0.002). The concordance analysis, however, indicated some dissimilarity between the recordings of the electrodes (CMAP, R1 = 0.31; latency, R1 = 0.26). These differences may be due to the area of the muscle mainly recorded by each electrode and/or to the additional activity from other muscles recorded by surface electrodes. On the other hand, the diaphragmatic responses observed in these patients with chronic obstructive pulmonary diseases were similar to those previously reported in healthy subjects.

Action Potentials↗
PubMed1993

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.

AIDS-Related Opportunistic Infections↗