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Comparative efficacy of jet nebulizer and metered dose inhaler with spacer device in the treatment of acute asthma.

OBJECTIVE: To compare the relative efficacy of jet nebulizer and metered dose inhaler (MDI) with spacer for the administration of aerosolized salbutamol in an acute exacerbation of bronchial asthma. DESIGN: Randomized prospective study. SETTING: Emergency Room. METHODS: In 60 subjects with acute asthma aged between 1 to 12 years, clinical and laboratory assessment of severity at recruitment included heart rate, respiratory rate, pulsus paradoxus, arterial blood gas analysis (all cases) and peak expiratory flow rate (wherever possible). The subjects were randomized into two equal groups to receive aerosolized salbutamol either via nebulizer (Group I) or MDI-spacer (Group II) as per the Consensus Guidelines. The response to therapy was sequentially assessed after 20, 40 and 60 minutes of institution of therapy. RESULTS: A significantly (p < 0.02) greater number of subjects in Group II presented with severe dyspnea and intercostal muscle retraction (subjective assessment). However, the objectively evaluable outcome parameters were comparable (p > 0.05) in both groups at presentation. All the outcome measures showed a significant (p < 0.05) improvement with time in both the groups. The recovery parameters were comparable (p > 0.05) at different time periods in the two groups. CONCLUSION: MDI-spacer is as effective as a nebulizer for the aerosolized administration of salbutamol in an acute exacerbation of asthma in children. However, for developing countries, distinct advantages (economic and power requirement) argue strongly for utilization of MDI-spacer in preference to nebulizer.

Acute Disease↗

[Carinal resection for primary lung cancer--with special attention to a modified double-barrel method].

Carinal resection for primary lung cancer was clinically evaluated. Carinal resection was performed in 18 patients, 17 males and one female, with a mean age of 64 years. Nine patients underwent carinal reconstruction and the other 9 sleeve or wedge pneumonectomy. The carinal reconstruction was of the montage type in one patient, the one-stoma type in 2, and the modified double-barrel method in 6. The modified double-barrel method is a technique that we developed by adding bronchial end-to-side anastomosis to the tracheobronchial end-to-end anastomotic site. A pedicled intercostal muscle flap was used for covering the anastomotic site. The postoperative respiratory complications after carinal reconstruction were anastomosis failure in 4 patients (pin-hole in 3) and respiratory failure in 2. However, no anastomosis stricture occurred, and recovery was satisfactory. There were no respiratory complications after pneumonectomy. One patient had renal failure before surgery and died of multiple organ failure 23 days after a montage type carinal reconstruction. The other 17 patients did well and could be discharged from the hospital and the overall mortality rate was 5.6%. No anastomosis stricture occurred in the modified double-barrel method. By carinal reconstruction covering of the anastomotic site is mandatory to prevent fatal postoperative complications.

Adenocarcinoma↗

Needle track seeding following percutaneous ethanol injection for treatment of hepatocellular carcinoma.

We report two cases of needle track seeding in the subcutaneous tissue and intercostal muscles following percutaneous ethanol injection for the treatment of hepatocellular carcinoma. In one patient, tumor seeding was observed 11 months after a total of 12 alcohol injections, and in the other patient, tumor seeding was observed 30 months after a total of 18 alcohol injections. The cases reported in the literature are discussed.

Administration, Cutaneous↗

[Results of resection of T3N0-2M0 non-small cell lung cancer according to involved organ and nodal status].

The purpose of this study was to evaluate the results of surgical treatment of T3N0-2M0 non-small cell lung cancer according to involved organ and nodal status. Between 1973 and July 1997, 157 patients with T3 non-small cell lung cancer were surgically treated in our department. Five-year survival was 23% for all cases, 35% for patients with curative resection, and 0% for patients with non-curative resection (p < 0.001). Five-year survival rate of patients with T3N0, T3N1, and T3N2 was 37%, 39%, and 3%, respectively (T3N0 vs T3N2, T3N1 vs T3N2, p < 0.01). According to the depth of chest wall involvement of T3N0 tumor, 5-year survival rate was 50% in the patients with the involvement of parietal pleura, 39% in the patients with the involvement of intercostal muscle, and 15% in the patients with the involvement of rib or more (parietal pleura vs rib or more, p < 0.05). In T3N0 patients with the involvement of only parietal pleura, the 5-year survival rate of parietal pleurectomy and en bloc chest wall resection was 43% and 46%, respectively (N.S.). Five-year survival rate of T3N1 patients with invasion in main stem bronchus was 46% and 3 of 5 patients of T3N0-1 tumor with pericardial invasion survived more than 5 years. From these results, T3N0 tumor involving chest wall without rib invasion, and T3N0-1 tumor involving main bronchus and pericardium are expected good survival. However, the prognosis of the patients with coexistent N2 disease or with incomplete resection remains poor in regardless with the type of involved organ. To correctly evaluate the surgical results of other types of T3 tumor, it is required to collect more cases or to perform multicenteric study.

Adult↗

[Surgical treatment of lung cancer with chest wall invasion].

From January 1986 to May 1998, 45 lung cancer patients with chest wall invasion (P3) underwent resection (40 male, 5 female), (median age 63.2 yrs (30-79)). Histological types were squamous cell carcinoma in 20, adenocarcinoma in 14, large cell carcinoma in 7, adenosquamous cell carcinoma in 2, and unknown in 2. Operative methods of lung resection were total pneumonectomy in 2, bilobectomy in 3, lobectomy in 38, and partial lung resection in 2. Resection was regarded as complete in 35 and incomplete in 10 patients. Thirty one patients had negative lymph nodes (N0), 9 had peribronchial or hilar lymph node metastases (N1), and 5 had mediastinal lymph node metastases (N2). The extent of tumor invasion to chest wall was P3a (invasion within parietal pleura) in 11, P3b-c (invasion to intercostal muscle) in 16, P3d (invasion to rib) in 18, patients. 5-year survival rate was totally 19.7%. Cisplatin based chemotherapy and concurrent thoracic radiation following surgery (CCRT) was performed in latest nine P3d cases. Partial response was observed in 5 of 9 cases (response rate 56%) and viable tumor cell in the primary site was not seen histologically in 5 of 9 cases. Three year survival rate was 46.9% for CCRT(+) 11.1% for CCRT(-). Acturial 5-year survival rate in P3a-d was 19.76%. P3d cases had poor survival, but CCRT improved prognosis of P3d cases.

Adult↗

Intercostal and abdominal muscle afferent influence on medullary dorsal respiratory group neurons.

Studies were performed on anesthetized, paralyzed, artificially ventilated cats. Phrenic (C5) efferent activity, dorsal respiratory group (DRG) neuron activity in the vicinity of the medullary solitary tract complex, and thoracic dorsal root compound action potentials were recorded during electrical stimulation of intercostal and lumbar nerves. DRG neurons were identified by their firing pattern and response to lung inflation. Phrenic activity (PA) was inhibited by stimulating external intercostal nerves T3-T10, internal intercostal nerves T3-T12, lateral branch of the main intercostal nerves T6-T12, or lumbar nerves 1-2. Stimulation of lower (T9-T11) intercostal or lumbar nerves produced a short duration (10-20 msec) facilitation of PA prior to the inhibition. Facilitation and inhibition of PA were correlated with recruitment of afferent fibers from muscle proprioceptors. Inspiratory neurons (I alpha and I beta) in the DRG were inhibited simultaneously with PA regardless of the nerves stimulated. DRG neurons which fired in phase with lung inflation (P cells) were unaffected by nerve stimulation even though PA was inhibited. Lower intercostal nerve (T9-T11) stimulation produced a brief facilitation of medullary neuron activity simultaneous with facilitation of PA. It is concluded that intercostal and abdominal muscle proprioceptor afferents, and perhaps cutaneous afferents, reflexly alter the activity of DRG inspiratory neurons (I alpha, I beta) which drive the phrenic motoneurons. The inhibitory effect is not via P cells but may be via other interneurons in close proximity to the I cells.

Action Potentials↗

Excitatory post-synaptic potentials from single muscle spindle afferents in external intercostal motoneurones of the cat.

1. The discharges of muscle spindle afferents from the external intercostal muscles of anaesthetized, paralysed cats were recorded from dorsal roots in continuity. The dynamic responses, regularities of firing and conduction velocities of the afferents were measured and used to characterize the afferents as primary-like or secondary-like. 2. The synchronization of afferent discharges was investigated by the construction of cross-correlation histograms from the simultaneously recorded discharges of pairs of afferents. The discharges of primary-like afferents with high dynamic responses were found to be synchronized within a few msec. The cardiac pulse was a strong contributary factor in this synchronization. 3. Intracellular recordings were made from external intercostal motoneurones, and spike-triggered averaging was used to reveal unitary e.p.s.p.s evoked by muscle spindle afferents which were from the same spinal cord segment. Dorsal roots other than the rootlet containing the afferent were cut to prevent the synchronization of afferent discharges from affecting the averaged e.p.s.p.s. 4. For primary-like afferents the mean amplitude of the e.p.s.p.s was 171 microV and the mean connectivity (the proportion of motoneurones connected by one afferent) was between 42 and 48%. 5. The amplitudes and shapes of the e.p.s.p.s varied with the respiratory phase, usually being larger in inspiration than in expiration and sometimes also having a longer time course. In particular some e.p.s.p.s showed that components, only represent in inspiration, which were interpreted as indicating polysynaptic connexions gated by the respiratory cycle. 6. The results are discussed in comparison with the connexions of individual muscle spindle afferents from other muscles, with particular reference to the conduction velocities of the afferents.

Action Potentials↗

Intercostal and abdominal muscle afferent influence on pneumotaxic center respiratory neurons.

The experiments were performed on mid-collicular decerebrated, vagotomized, paralyzed, artificially ventilated cats. Phrenic (PA) and pneumotaxic center (PC) respiratory neuron (extracellular) activities were recorded during electrical stimulation of intercostal nerve proprioceptor afferents (external, internal or lateral intercostal nerves). Intercostal nerve stimulation (INS) of sufficient intensity to reduce PA also reduced the activity of phasic PC I-neurons and the I-modulated portion of tonic firing I-neurons. The stimulus-response latency for the reduction in PA was always shorter than the latency for the reduction in I-neuron activity. Baseline tonic activity (during E-phase) was unaffected by INS in most tonic I-neurons. The predominant response of PC IE- and E-neurons to INS was augmentation of their activity. Stimulus-response latency studies showed that the increase in IE- and E-neuron activity occurred after the decrease in PA. It is concluded that: (1) the reduced PC I-neuron activity following INS is due primarily to disfacilitation resulting probably from decreased activity in medullary I-neurons that drive the PC I-neurons, (2) PC IE- and E-neurons are not the primary neurons mediating the inspiratory inhibitory effects of intercostal and abdominal muscle proprioceptors on medullary I drive, (3) the changes in PC IE- and E-neuron activity is not due secondarily to changes in DRG and VRG IE- or E-neuron activities, and (4) the reflex effects are due to stimulation of low threshold Group I afferent fibers.

Abdomen↗

Respiratory muscle fiber morphometry. Correlation with pulmonary function and nutrition.

To examine the relationship between nutrition, pulmonary function, respiratory muscle strength, and respiratory muscle morphometry, we compared physiologic data and muscle morphometry obtained from internal intercostal, external intercostal, and latissimus dorsi muscle biopsies in 68 patients who were having a thoracotomy. We stained the biopsies for myosin ATPase and measured the proportions and diameters of the type 1 and type 2 fibers. There were more qualitative changes in the external intercostal muscles than in the other two, and some of these changes related to the incidence of malignancy. There were more type 1 fibers in the external intercostal (64 +/- 10 percent) and internal intercostal muscles (59 +/- 12 percent) than in the latissimus dorsi (44 +/- 13 percent) (p less than 0.005). The mean diameter of the type 2 fibers in the external intercostal muscles was less (44 mu +/- 7 mu) than the diameter in the latissimus dorsi (51 mu +/- 9 mu) and the internal intercostal muscles (52 mu +/- 8 mu) (p less than 0.01). The diameters of both fiber types were greater in men than in women. There was no significant relationship between measures of pulmonary function or respiratory muscle strength and muscle fiber proportions and diameters. There were significant correlations between the percentage of ideal body weight and type 1 and type 2 fiber diameters. We conclude that sex and nutrition influence respiratory muscle morphometry.

Biopsy↗

Nucleus retroambigualis respiratory neurons: responses to intercostal and abdominal muscle afferents.

Studies were performed on anesthetized (Dial), paralyzed, vagotomized, artificially ventilated cats. Phrenic efferent activity, ventral respiratory group neuron activity in the region of the nucleus retroambigualis and, in some instances, thoracic dorsal root compound action potentials were recorded during electrical stimulation of intercostal nerve afferents (INS). Phrenic activity and inspiratory (I) neurons were inhibited by stimulating external, internal and lateral intercostal nerve afferents. Some expiratory (E)-neurons were also inhibited by these afferents. No I or E-neurons were facilitated with INS. Changes in I and E activity were correlated with muscle proprioceptor and cutaneous receptor afferent fibers. It is concluded that the dominant effect of intercostal and abdominal muscle proprioceptive afferent information on medullary respiratory activity in inhibition of inspiratory activity.

Abdominal Muscles↗

Response of the inspiratory intercostal [correction of intercoastal] muscles to increased inertial loads.

To test the hypothesis that the external intercostals and levator costae constitute an inspiratory reserve system, we have examined the response of these muscles to increased inertial loads. Weights were t hus attached sequentially to the ribs in ten lightly anesthetized, spontaneously breathing dogs. As weights were attached, the ribs were progressively displaced caudally at end-expiration, so that the external intercostal muscles were lengthened. In addition, the cranial motion of the ribs during inspiration was gradually reduced, the inspiratory shortening of external intercostal disappeared, and the external intercostal and levator costae inspiratory EMG activities increased. The parasternal intercostal inspiratory activity, however, remained unchanged. Studies also showed that: (1) the increases in external intercostal activity appeared with the first loaded breath and disappeared as soon as the load was removed; (2) these increases were related to the suppression of the inspiratory muscle shortening, rather than to the increase in precontraction muscle length or to vagal inputs; and (3) denervation of the external intercostal caused inspiratory muscle lengthening but had little effect on the inspiratory motion of the ribs. These observations thus indicate that increased inertial loads on the ribs trigger reflexes, possibly spindle reflexes, which cause selective increases in external intercostal and levator costae inspiratory EMG activities. In that sense, the present findings are consistent with the idea that these two muscles constitute an inspiratory reserve system. However, it appears that the major effect of these increased activities is simply to prevent the muscles from lengthening during inspiration.

Animals↗

Respiration-related activity in the biceps brachii muscle after intercostal-musculocutaneous nerve transfer.

Needle EMG and polygraphic recordings of respiration and biceps activity were obtained in 7 patients who had undergone intercostal to musculocutaneous nerve transfer because of severe traumatic injury to the brachial plexus. EMG activity during expiration and inspiration was assessed during quiet breathing, deep breathing, and during sustained inspiration and expiration, and compared to the clinical strength of the biceps muscle. Biceps activity was consistently found during both expiration and inspiration, and in either case separately related to the flexion force levels. Initially this relationship appeared equally strong for both phases. With time, control over flexion changes from a completely respiratory-driven control to a conscious volitional control; however, involuntary effects of respiration always remained present in polygraphic recordings. Theoretical explanations for the change in control are put forward.

Adolescent↗

Effect of pulmonary stretch receptor feedback and CO(2) on upper airway and respiratory pump muscle activity in the rat.

1. Our purpose was to examine the effects of chemoreceptor stimulation and lung inflation on neural drive to tongue protrudor and retractor muscles in the rat. 2. Inspiratory flow, tidal volume, transpulmonary pressure, compliance and electromyographic (EMG) activity of genioglossus (GG), hyoglossus (HG) and inspiratory intercostal (IIC) muscles were studied in 11 anaesthetized, tracheotomized and spontaneously breathing rats. Mean EMG activity during inspiration was compared with mean EMG activity during an occluded inspiration, at each of five levels of inspired CO(2) (0, 3, 6, 9 and 12 %). 3. Lung inflation suppressed EMG activity in all muscles, with the effect on both tongue muscles exceeding that of the intercostal muscles. Static elevations of end-expiratory lung volume evoked by 2 cmH(2)O positive end-expiratory pressure (PEEP) had no effect on tongue muscle activity. 4. Despite increasing inspiratory flow, tidal volume and transpulmonary pressure, the inhibition of tongue muscle activity by lung inflation diminished as arterial PCO2 (P(a),CO(2)) increased. 5. The onset of tongue muscle activity relative to the onset of IIC muscle activity advanced with increases in P(a),CO(2) but was unaffected by lung inflation. This suggests that hypoglossal and external intercostal motoneuron pools are controlled by different circuits or have different sensitivities to CO(2), lung inflation and/or anaesthetic agents. 6. We conclude that hypoglossal motoneuronal activity is more strongly influenced by chemoreceptor-mediated facilitation than by lung volume-mediated inhibition. Hypoglossal motoneurons driving tongue protrudor and retractor muscles respond identically to these stimuli.

Animals↗

Functional magnetic resonance imaging and control over the biceps muscle after intercostal-musculocutaneous nerve transfer.

OBJECT: Recent progress in the understanding of cerebral plastic changes that occur after an intercostal nerve (ICN)-musculocutaneous nerve (MCN) transfer motivated a study with functional magnetic resonance (fMR) imaging to map reorganization in the primary motor cortex. METHODS: Eleven patients with traumatic root avulsions of the brachial plexus were studied. Nine patients underwent ICN-MCN transfer to restore biceps function and two patients were studied prior to surgery. The biceps muscle recovered well in seven patients who had undergone surgery and remained paralytic in the other two patients. Maps of neural activity within the motor cortex were generated for both arms in each patient by using fMR imaging, and the active pixels were counted. The motor task consisted of biceps muscle contraction. Patients with a paralytic biceps were asked to contract this muscle virtually. The location and intensity of motor activation of the seven surgically treated arms that required good biceps muscle function were compared with those of the four arms with a paralytic biceps and with activity obtained in the contralateral hemisphere regulating the control arms. Activity could be induced in the seven surgically treated patients whose biceps muscles had regained function and was localized within the primary motor area. In contrast, activity could not be induced in the four patients whose biceps muscles were paralytic. Neither the number of active pixels nor the mean value of their activations differed between the seven arms with good biceps function and control arms. The weighted center of gravity of the distribution of activity also did not appear to differ. CONCLUSIONS: Reactivation of the neural input activity for volitional biceps control after ICN-MCN transfer, as reflected on fMR images, is induced by successful biceps muscle reinnervation. In addition, the restored input activity does not differ from the normal activity regulating biceps contraction and, therefore, has MCN acceptor qualities. After ICN-MCN transfer, cerebral activity cannot reach the biceps muscle following the normal nervous system pathway. The presence of a common input response between corticospinal neurons of the ICN donor and the MCN acceptor seems crucial to obtain a functional result after transfer. It may even be the case that a common input response between donor and acceptor needs to be present in all types of nerve transfer to become functionally effective.

Adolescent↗

Participation of cholinergic systems in the bulbar mechanisms of the regulation of breathing.

The reactions of the respiratory muscles of symmetrical intercostals given bi- and unilateral applications of acetylcholine and its antagonists (atropine and spasmolytin) to various segments of the dorsal surface of the medulla oblongata, the entire region of the projection of the respiratory center, primarily its medial or primarily its lateral zones, were studied in rats. A relationship of the effect to the level of activity of cholinergic structures and the localization of the exposure, was identified. The results obtained suggest an uneven distribution of the M and N cholinoreactive systems in homotopic structures of the medulla oblongata. A conclusion was drawn of the undoubted participation of cholinergic mediation in the mechanisms of integration of paired divisions of the bulbar respiratory center and the central regulation of respiration.

Acetylcholine↗

[Effects of halothane on the electrical activity of respiratory muscles in rats].

This study was designed to investigate the effects of halothane on the electrical activity of the respiratory muscles in rats. Indeed, halothane is known to reduce end-expiratory lung volume, both in man and in animal; this may be due to altered activity in the respiratory muscles. The electrical activity of the diaphragm, parasternal, intercostal and abdominal muscles were recorded using intramuscular electrodes in ten rats weighing between 400 and 450 g each. The rats were prepared under light halothane anaesthesia (tracheostomy, laparotomy, electrode positioning, plaster of Paris cast to impede leg movements). They were placed prone in a 20 1 plexiglass chamber, and allowed to awake. Thereafter halothane was vaporized in this chamber at a known concentration, until the animals no longer reacted to tail pinching. The measurements were carried out during the awake state, and under 2 vol % halothane. Muscle tone was assessed by the thickness of baseline inspiratory muscle activity at the end of expiration (maximally amplified raw electromyographic signals). The measurement of phasic electrical activity was carried out using peak inspiratory integrated electromyographic signals. Under halothane, phasic activity of the diaphragm was slightly reduced (p less than 0.05), whereas tonic activity remained unchanged. Parasternal intercostal muscle activity, both tonic and phasic, was also decreased during halothane anaesthesia (p less than 0.001). No phasic activity occurred in the abdominal muscles, but muscle tone was reduced during halothane administration (p less than 0.01). In rats, the decrease in intercostal muscle tone under halothane anaesthesia could play a major part in the fall in functional residual capacity.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

A monoclonal antibody that defines rostrocaudal gradients in the mammalian nervous system.

Spinal cord axons display a rostrocaudal, positional bias in their innervation of sympathetic ganglia and intercostal skeletal muscles. In an effort to examine the molecular basis of this positional specificity, we used the cyclophosphamide immunosuppression method to produce monoclonal antibodies that bind preferentially to rostral ganglia. The staining distribution of one of these antibodies, ROCA1, has been analyzed using a novel histological method. A graded decline in binding is observed along the chain of adult rat sympathetic ganglia, as well as in the nerves innervating intercostal muscles. The antigen is identified on immunoblots as a 65 kd protein, whose distribution corresponds to the pattern found histologically. Surprisingly, ROCA1 appears to bind to glial cells, implying rostrocaudal, molecular differences in their surfaces.

Animals↗