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Abstract  Few studies focused on concomitant electromyographic recordings of pelvic floor muscles and muscles involved in cough initiation. The objective of this study was to investigate the temporal course of external anal sphincter activation during coughing. Informed consent was obtained from ten healthy volunteers and ten women presenting with stress urinary incontinence (SUI). Simultaneously, recordings of electromyographic activity of external intercostal muscles (EIC EMGi) and external anal sphincter (EAS EMGi) during coughing have been performed. It was chosen to study intercostals muscles because they are synchronous to diaphragmatic muscle during cough initiation. Median (interquartile range) latency between the onset of the EAS EMGi and the onset of the EIC EMGi was −210 ms (−398; −135) and 0 ms (−30; 흝.7) in volunteers’ group and in SUI group, respectively (p = 0.0009). Abnormal temporal course of external anal sphincter activation is observed during coughing in women presenting with SUI compared to healthy volunteers. [ABSTRACT FROM AUTHOR]

Background. Scoliosis is a side spinal curvature, which disturbs body statics and symmetry. Most often, it is associated with postural defects in children with a weakened, flab muscle- -ligament system. In progressive scoliosis, spine deformations cause changes in the structure and mobility of the thorax. The trunk moves in the direction of curvature convexity, affecting the arrangement of ribs and the activity ofrespiratory muscles. It results in the decrease of thorax capacity and disturbance of lung ventilation. Decrease of ventilation indicators values is proportional to the increase of spinal curvature rate. The aim of this study was to eveluate selected anthropometric and spirometric indices in low grade scoliosis affectig teenagers. Material and methods. The sample comprised a group of girls and boys aged of 13-15 years who attend correction-gymnastics classes. The study involved anthropometric and spirometric measurements. Anthropometric measurements comprised: height, weight, chest circumference, its mobility, respiratory circumference, Pignet's index and Martha's index and chest growth. Spirometric measurement comprised: spirometry, volume transfer and maximal respiratory ventilation in the subjects sitting on their heels. Results. The anthropometric measurements revealed higher values of height, weight and chest circumference while respiration, rest and expiration in boys. Chest mobility indicator was higher in girls. VC, FEV1 and FVCEX and FVCIN, values were lower than normal values. MVV, MEF50 and PEF values were significantly higher than normal values. Conclusions. Lower average FEV1 values and significantly higher MEF50 values suggest the decrease in the intercostal muscle power and correlate with the anthropometric indices of chest mobility and girth. High MVV values suggest participation of shoulder gilrdle auxiliary intercostal muscles. [ABSTRACT FROM AUTHOR]

Abstract: Respiratory parameters and sound were recorded during professional flute playing in order to assess what physiological processes were associated with the control of sound production that results in ‘breath support’ which in turn is associated with high quality playing. Four standing young professional flautists played flute excerpts with and without breath support. Recordings included optoelectronic plethysmographic measurements of chest wall volume (V cw) and its compartments, surface electromyography of the scalene, lateral abdominal, rectus abdominus, parasternal and sternocleidomastoid muscles, mouth pressure, and sound. Flow was estimated from differentiating V cw during playing. Results showed that flute support entails antagonistic contraction of non-diaphragmatic inspiratory muscles that tends to hold the rib cage at higher lung volume. This relieves the expiratory muscles from the task of producing the right mouth pressure, especially at the end of the phrases, so they can contribute more to the finer control of mouth pressure modulations required for high quality playing. [Copyright &y& Elsevier]

Background: The external intercostal muscles are chronically exposed to increased inspiratory loading and to continuous hypoxia-reoxygenation cycles in patients with obstructive sleep apnoea syndrome (OSAS). It was therefore hypothesised that oxidative stress levels would be increased in these muscles, and that treatment with continuous positive airway pressure (CPAP) would modify the oxidative stress levels and improve muscle dysfunction. Methods: A case-control study and a case-case study were conducted on the external intercostal muscles of 12 patients with severe OSAS (before and after 6 months of treatment with CPAP) and 6 control subjects. Reactive carbonyl groups, malondialdehyde (MDA)-protein and hydroxynonenal (HNE)-protein adducts, antioxidant enzyme levels, 3-nitrotyrosine and fibre type proportions were measured using immunoblotting and immunohistochemistry. Results: Compared with controls, the intercostal muscles of patients with OSAS had higher levels of protein carbonylation (median values 3.06 and 2.45, respectively, p=0.042), nitration (median values 1.64 and 1.05, respectively, p=0.019) and proportions of type I fibres (median values 57% and 48%, respectively, p=0.03.5) and reduced respiratory muscle endurance (median values 3.2 and 9.5 mm, respectively, p=0.001). Positive correlations were found between MDA-protein and HNE-protein adducts (r=0.641, p=0.02 and r=0.594, p=0.05, respectively) and 3-nitrotyrosine (r=0.625, p=0.03) and the apnoea-hypopnoea index (AHI) in all the patients with OSAS. Although treatment with CPAP significantly improved the AHI and oxygen desaturation, muscle oxidative stress levels and respiratory muscle endurance were not affected. Conclusions: This study suggests that inspiratory muscle performance is not completely restored after long-term treatment with CPAP. [ABSTRACT FROM AUTHOR]

Abstract Objectives  The present study was undertaken to investigate the significance of 2-deoxy-2-[F-18]fluoro-d-glucose (FDG) uptake in the intercostal muscles (ICM) and prominent visualization of right ventricle (RV) in FDG-positron emission tomography (PET) scans and its implications. Methods  Patients identified to have FDG uptake in the ICM with or without prominent visualization of the RV either incidentally or in the background of an existing explanatory cause at the time of FDG-PET studies were included in this retrospective study. These patients had undergone FDG-PET either for ruling out malignancy or for disease monitoring purposes in setting a proven malignancy. We reviewed the clinical and investigational records (including computed tomography [CT] thorax, chest X-ray, 2-D echo and pulmonary function tests, and arterial blood gas analysis) of the group with incidental FDG uptake for revelation of a pathology explaining such uptake. Results  A total of 14 cases with 16 FDG-PET studies were identified from the retrospective examination of case records. One patient had three FDG-PET at different time points of his disease course. The patient population included 13 males and one female with age range 46–88 years. The patients were classified into two groups: (1) cases with isolated ICM uptake (n = 10); (2) cases with both ICM and RV uptake (n = 4). Among 10 patients with isolated ICM uptake, in six patients it was a serendipitous observation, whereas four patients had existing explanatory cause at the time of FDG-PET. The causes found to be associated included COPD, asthma, recent heart failure, interstitial lung disease (post external radiotherapy) and pulmonary embolism, atelectasis with pleural effusion. In all four cases with associated RV uptake, there was evidence of pulmonary hypertension (PH). Among these, in one patient this was a serendipitous observation. He had evidence of interstitial lung disease (ILD) in CT thorax, and 2-D echo showed moderate PH. The remaining three patients had cor pulmonale secondary to COPD, pneumoconiosis, and Swyer James Syndrome with associated severe PH. The SUVmax ratio of the RV-to-LV free wall ranged from 0.53 to 1.04 in the cases with prominent RV uptake. One patient had multiple FDG-PET studies and have shown reduction of RV uptake in the last scan consistent with the clinical impression of improvement of cor pulmonale. Conclusion  Both intercostal muscle and prominent RV uptake in FDG-PET can be associated with a spectrum of causes (including both obstructive and restrictive airway diseases) that lead to breathing exertion. These are important markers, which could signify underlying pulmonary disease and pulmonary hypertension, respectively. Associated prominent RV uptake strongly indicates presence of pulmonary hypertension and the uptake in the right heart can subserve a valuable surrogate marker in the treatment- monitoring scenario of a known PH. [ABSTRACT FROM AUTHOR]

Among the conservatively treated patients with obstetrical paralysis after delivery in the vertex presentation, cross reinnervation sometimes occurs in the course of their recovery and co-contraction of multiple muscles impairs smooth upper limb motion. Such co-contraction of the biceps and the triceps inhibits normal elbow motion, making it impossible to use the elbow effectively in daily activities, despite adequate strength in these muscles. To overcome biceps/triceps co-contraction, we performed intercostal nerve transfer to the musculocutaneous nerve for three patients of age 11 months, 6 years and 9 years, respectively, and to the motor branches of the triceps for two patients of age 4 and 14 year-old, respectively. During the average follow-up period of 5.6 (range 1–11.5) years, the power of the reinnervated muscle improved to more than M3, and smooth motion of the elbow independently of shoulder motion was restored. [Copyright &y& Elsevier]

The inspiratory intercostal muscles elevate the ribs and thereby elicit a fall in pleural pressure (ΔPpl) when they contract. In the present study, we initially tested the hypothesis that this iΔPpl does, in turn, oppose the rib elevation. The cranial rib displacement (Xr) produced by selective activation of the parasternal intercostal muscle in the fourth interspace was measured in dogs, first with the rib cage intact and then after ΔPpl was eliminated by bilateral pneumothorax. For a given parasternal contraction, Xr was greater after pneumothorax; the increase in Xr per unit decrease in ΔPpl was 0.98 ± 0.11 mm/cmH2O. Because this relation was similar to that obtained during isolated diaphragmatic contraction, we subsequently tested the hypothesis that the increase in Xr observed during breathing after diaphragmatic paralysis was, in part, the result of the decrease in ΔPpl, and the contribution of the difference in iΔPpl to the difference in Xr was determined by using the relation between Xr and ΔPpl during passive inflation. With diaphragmatic paralysis, Xr during inspiration increased approximately threefold, and 47 ± 8% of this increase was accounted for by the decrease in ΔPpl. These observations indicate that 1) ΔPpl is a primary determinant of rib motion during intercostal muscle contraction and 2) the decrease in ΔPpl and the increase in intercostal muscle activity contribute equally to the increase in inspiratory cranial displacement of the ribs after diaphragm paralysis. [ABSTRACT FROM AUTHOR]

Intercostal hernias develop most often as a result of a blunt or penetrating thoracoabdominal trauma. We know of no prior report of a spontaneously occuring intercostal hernia. This study presents a review of the published literature that deals with this uncommon phenomenon, along with a discussion of our patient’s clinical presentation and imaging findings. [ABSTRACT FROM AUTHOR]

Neural drive to inspiratory pump muscles is increased under many pathological conditions. This study determined for the first time how neural drive is distributed to five different human inspiratory pump muscles during tidal breathing. The discharge of single motor units (n = 280) from five healthy subjects in the diaphragm, scalene, second parasternal intercostal, third dorsal external intercostal, and fifth dorsal external intercostal was recorded with needle electrodes. All units increased their discharge during inspiration, but 41(15%) discharged tonically throughout expiration. Motor unit populations from each muscle differed in the timing of their activation and in the discharge rates of their motor units. Relative to the onset of inspiratory flow, the earliest recruited muscles were the diaphragm and third dorsal external intercostal (mean onset for the population after 26 and 29% of inspiratory time). The fifth dorsal external intercostal muscle was recruited later (43% of inspiratory time; P < 0.05). Compared with the other inspiratory muscles, units in the diaphragm and third dorsal external intercostal had the highest onset (7.7 and 7.1 Hz, respectively) and peak firing frequencies (12.6 and 11.9 Hz, respectively; both P < 0.05). There was a unimodal distribution of recruitment times of motor units in all muscles. Neural drive to human inspiratory pump muscles differs in timing, strength, and distribution, presumably to achieve efficient ventilation. [ABSTRACT FROM AUTHOR]

Ascites, a complicating feature of many diseases of the liver and peritoneum, commonly causes dyspnea. The mechanism of this symptom, however, is uncertain. In the present study, progressively increasing ascites was induced in anesthetized dogs, and the hypothesis was initially tested that ascites increases the impedance on the diaphragm and, so, adversely affects the lung-expanding action of the muscle. Ascites produced a gradual increase in abdominal elastance and an expansion of the lower rib cage. Concomitantly, the caudal displacement of the diaphragm and the fall in airway opening pressure during isolated stimulation of the phrenic nerves decreased markedly; transdiaphragmatic pressure during phrenic stimulation also decreased. To assess the adaptation to ascites of the respiratory system overall, we subsequently measured the changes in lung volume, the arterial blood gases, and the electromyogram of the parasternal intercostal muscles during spontaneous breathing. Tidal volume and minute ventilation decreased progressively as ascites increased, leading to an increase in arterial Pco2 and parastemal intercostal inspiratory activity. It is concluded that 1) ascites, acting through an increase in abdominal elastance and an expansion of the lower rib cage, impairs the lung-expanding action of the diaphragm; 2) this impairment elicits a compensatory increase in neural drive to the inspiratory muscles, but the compensation is not sufficient to maintain ventilation; and 3) dyspnea in this setting results in part from the dissociation between increased neural drive and decreased ventilation. [ABSTRACT FROM AUTHOR]

Electromyography (EMG) of respiratory muscles is a reliable method of assessing the ventilatory muscle function, but still its use has not been fully utilized to determine the occupational and environmental hazards on respiratory muscles. Therefore, EMG of intercostal muscles was performed to determine the dose response effect of cement dust on respiratory muscles competence. Matched cross-sectional study of EMG in 50 non-smoking cement mill workers with an age range of 20 – 60 years, who worked without the benefit of cement dust control ventilation or respiratory protective devices. EMG was performed by using surface electrodes and chart recorder. Significant reduction was observed in number of peaks (p < 0.0005), maximum peak amplitude (p < 0.0005), peak-to-peak amplitude (p < 0.0005) and duration of response (p < 0.0005) in cement mill workers compared to their matched control. Cement dust impairs the intercostal muscle competence and stratification of results shows a dose-effect of years of exposure in cement mill. [ABSTRACT FROM AUTHOR]

Studies in experimental animals indicate that chronic increases in neural drive to limb muscles elicit a fast-to-slow transformation of fiber-type proportions and myofibrillar proteins. Since neural drive to the parasternal intercostal muscles (parasternals) is chronically increased in patients with severe chronic obstructive pulmonary diseases (COPDs), we carried out the present study to test the hypothesis that the parasternals of COPD patients exhibit an increase in the proportions of both slow fibers and slow myosin heavy chains (MHCs). Accordingly, we obtained full thickness parasternal muscle biopsies from the third interspace of seven COPD patients (mean ± SE age: 59 ± 4 yr) and seven age-matched controls (AMCs). Fiber typing was done by immunohistochemistry, and MHC proportions were determined by SDS-PAGE followed by densitometry. COPD patients exhibited higher proportions of slow fibers than AMCs (73 ± 4 vs. 51 ± 3%; P < 0.01). Additionally, COPD patients exhibited higher proportions of slow MHC than AMCs (56 ± 4 vs. 46 ± 4%, P < 0.04). We conclude that the parasternal muscles of patients with severe COPD exhibit a fast-to-slow transformation in both fiber-type and MHC proportions. Previous workers have demonstrated that remodeling of the external intercostals, another rib cage inspiratory muscle, elicited by severe COPD is characterized by a slow-to-fast transformation in both fiber types and MHC isoform proportions. The physiological significance of this difference in remodeling between these two inspiratory rib cage muscles remains to be elucidated. [ABSTRACT FROM AUTHOR]

Abstract: Objective: Bronchopleural fistula is a serious complication of pulmonary resection. For anatomical reasons, lower lobectomy is thought to carry a higher risk for bronchopleural fistula. We investigated the efficacy of bronchial stump reinforcement with a pedicled intercostal muscle flap after lower lobectomy and compared the responses in patients treated with the flap, without the flap, and with other types of flap. We also investigated whether harvesting the intercostal muscle flap leads to an increase in blood loss during surgery and whether the type of flap influences chest-tube volume and pain after surgery. Methods: One hundred and sixty-eight patients had lower or middle-lower lobectomy between January 1990 and December 2004. The bronchial stumps were treated in one of the three ways: covered with an intercostal muscle flap (116 patients, group A), not covered with a muscle flap (32 patients, group B), or covered with free fat or pleura (20 patients, group C). In a separate study, we compared the blood loss during surgery, and chest-tube volume and pain after surgery between patients treated with the intercostal muscle flap (23 patients) and non-intercostal muscle flap (32 patients). Results: No patients in group A exhibited bronchopleural fistula, and two patients in group B and one patient in group C exhibited bronchopleural fistula. These differences were not significant. Blood loss, chest-tube volume, and pain score after surgery did not differ significantly between treatment groups. Conclusions: Bronchial stump reinforcement with the intercostal muscle flap after pulmonary resection is safe and effective when performed during lower and lower-middle lobectomy and does not increase the risk of complications. [Copyright &y& Elsevier]

Abstract: Background: Traumatic rupture of the diaphragm resulting from blunt abdominal trauma remains a challenging clinical entity. Description of such type of injuries in children is scarce in the literature. Purpose: The aim of this study was to present this special form of injury in the pediatric age group and compare the different aspects of diaphragmatic injury with that occurring in adults. Patients and Methods: Ten cases of diaphragmatic rupture after blunt trauma in children were reported. The presentations, findings, and management were described. Results: This study included 7 boys and 3 girls aged 3 to 16 years. Trauma in 8 cases resulted from motor vehicle or auto-pedestrian accidents and 2 from falling from a height. Chest radiograph shows suggestive signs of diaphragmatic injuries in 7 occasions including intrathoracic visceral herniation in 4 cases and hemothorax in 3 cases. Associated injuries were found in 5 cases in the form of rib fractures in 3 cases and lung contusion in 2 cases. Lung tear, gut perforation, and liver tear were each reported once. Isolated diaphragmatic injury is reported in 5 cases. Three cases were repaired via thoracotomy or laparo-thoracotomy and 7 cases via midline laparotomy. On exploration, we found diaphragmatic avulsion of the costal origin in 5 cases, 3 left and 2 right contrary to tears, of which 4 were left sided and 1 right sided. Primary repair was conducted in 7 cases and an intercostal muscle flap was used in 3 cases. No mortalities were reported. Conclusions: This series of diaphragmatic rupture in children reveals the following: (1) Avulsion of the costal origin of the diaphragm is a peculiar type of injury described in children (5 of 10). (2) The intercostal muscle flap is a useful tool to bridge diaphragmatic defects. (3) Isolated diaphragmatic injuries do occur in children more frequently than in adults. (4) As in adults, diaphragmatic rupture prevails in the left side, and purposeful surgical diagnosis and early management determine the effectiveness of treatment. [Copyright &y& Elsevier]

This study presents a perfused preparation for evaluation of metabolism in pig intercostal muscle in vitro. Preserved vessels and nerves to an intercostal segment including two adjacent ribs allowed for tissue perfusion and electrical stimulation with measurement of contraction force, oxygen consumption and 31P-magnetic resonance spectroscopy (31P-MRS). When perfused at rest with Krebs–Ringer buffer, the preparation maintained physiological levels of phosphocreatine (PCr), inorganic phosphate (Pi), ATP and pH at a stable oxygen consumption of 0.51 ± 0.01 μmol min−1 g−1 for more than 2 h. Tonic stimulation of the nerve caused anaerobic energy consumption as PCr and pH decreased, and both variables recovered after the contraction with half-time values of ∼7 min. Force increased to 0.040 N g−1 (range, 0.031–0.103 N g−1) and it gradually decreased by about 70% during the subsequent 5 min of stimulation. The calculated free ADP concentration increased from 7.4 ± 2.1 nmol g−1 at rest to 28 ± 12 nmol g−1 (mean ±s.d.) by the end of the stimulation. Thus anaerobic ATP turnover was zero at rest, 6.1 ± 2 μmol min−1 g−1 during the first minute of stimulation and 3.5 ± 0.5 μmol min−1 g−1 during the two last minutes, corresponding to the drop in force. When the preparation was left unperfused, anaerobic ATP turnover averaged 0.40 ± 0.15 μmol min−1 g−1 for the first 10 min. The preparation can also be applied to human intercostal muscles, as demonstrated in one preliminary experiment. The results demonstrate a stable and functional in vitro preparation of intact perfused intercostal muscles in the pig. [ABSTRACT FROM AUTHOR]

This paper describes the ultrasonographic appearance, location and size of the spleen in 50 healthy commercial milk cows destined for slaughter. The intercostal spaces of the left thoracic wail were scanned with a 3.5 MHz linear transducer. In each intercostals space, the appearance of the splenic parenchyma, the dorsal and ventral margins and the distance between them, and the diameter of the splenic vessels were recorded. The spleen was seen in intercostal spaces 7-12. It was 2.0-5.0 cm thick, and tapered ventrally. The splenic capsule appeared as an echogenic line. The splenic parenchyma consisted of numerous small regularly spaced echoes, and vessels within the parenchyma appeared as anechoic round to oval or elongated images. The long axis was oblique, running caudodorsal to cranioventral. The distance from the dorsal margin of the spleen to the midline of the back was greatest in the 7th intercostal space (60.9 ± 6.81) and smallest in the 12th intercostal space (12.7 ± 2.85 cm). The extent of the spleen was greatest in the 8th intercostal space (24.9 ± 10.77 cm) and smallest in the 12th intercostal space (9.5 ± 5.38 cm). The mean diameter of the splenic vessels ranged from 0.66 -± 0.28 to 0.90 ± 0.65 cm, depending on the intercostal space scanned. Ultrasonography of the spleen in healthy cows provides information that can be used as a reference when examining cattle with suspected splenic disease. [ABSTRACT FROM AUTHOR]

Inflation induces a marked decrease in the lung-expanding ability of the diaphragm, but its effect on the parasternal intercostal muscles is uncertain. To assess this effect, the phrenic nerves and the external intercostals were severed in anesthetized, vagotomized dogs, such that the parasternal intercostals were the only muscles active during inspiration, and the endotracheal tube was occluded at different lung volumes. Although the inspiratory electromyographic activity recorded from the muscles was constant, the change in airway opening pressure decreased with inflation from -7.2 ± 0.6 cmH2O at functional residual capacity to -2.2 ± 0.2 cmH2O at 20-cmH2O transrespiratory pressure (P < 0.001). The inspiratory cranial displacement of the ribs remained virtually unchanged, and the inspiratory caudal displacement of the sternum decreased moderately. However, the inspiratory outward rib displacement decreased markedly and continuously; at 20 cmH2O, this displacement was only 23 ± 2% of the value at functional residual capacity. Calculations based on this alteration yielded substantial decreases in the change in airway opening pressure. It is concluded that, in the dog, 1) inflation affects adversely the lung-expanding actions of both the parasternal intercostals and the diaphragm; and 2) the adverse effect of inflation on the parasternal intercostals is primarily related to the alteration in the kinematics of the ribs. As a corollary, it is likely that hyperinflation also has a negative impact on the parasternal intercostals in patients with chronic obstructive pulmonary disease. [ABSTRACT FROM AUTHOR]

Summary: Asthma patients have been reported to be sensitive to breathlessness, independent of the degree of airway obstruction. Paying attention and task performance may induce changes in breathing pattern and these in turn may mediate such a feeling. The present experiment investigates whether strained breathing induced by an arithmetic task was different in children with asthma compared to healthy children. Methods: Seven healthy and eight asthmatic but symptom-free school children were equipped with electrodes for surface electromyographic (EMG) measurements of diaphragm, abdominal and intercostal (IC) muscles and with a strain gauge to monitor the pattern of breathing at rest and during an arithmetic task. The relative duration of exhalation and the relative speed of exhalation are used as measures of straining. The phase angle of maximal respiratory muscle activities relative to the maximal chest extension (MCE) are additional discriminating parameters. Results: Asthmatic children breathed more slowly and already at rest the phase of their respiratory muscle activity appears to be different. While in healthy children the maximal activity of the (left)abdominal muscles occurred 5±29% later than the MCE, in children with asthma the maximal activity occurred 26±30% of the cycle earlier than MCE. In children with asthma the activity of the IC muscles starts weaning already at 10±30% before MCE, in contrast to the healthy children in which intercostal muscle weaning starts only at 1±24% after MCE. During arithmetic, the significant difference between the groups in this respect disappeared. Conclusion: Children with asthma show, even at rest, signs of respiratory muscle straining, probably in order to keep close control over the airflow in a similar way as healthy children during mental tasks. Such a ‘careful’ breathing pattern may work to prevent airway irritation also when they are free of symptoms. [Copyright &y& Elsevier]

Traditionally, auscultation is applied to the diagnosis of either respiratory disturbances by respiratory sounds or cardiac disturbances by cardiac sounds. In addition, for sleep apnea syndrome diagnosis, snoring sounds are also monitored. The present study was aimed at synchronous detection of all three sound components (cardiac, respiratory, and snoring) from a single spot. The sounds were analyzed with respect to the cardiorespiratory activity, and to the detection and classification of apneas. Sound signals from 30 subjects including 10 apnea patients were detected by means of a microphone connected to a chestpiece which was applied to the heart region. The complex nature of the signal was investigated using time, spectral, and statistical approaches, in connection with self-defined time-based and event-based characteristics. The results show that the obstruction is accompanied by an increase of statistically relevant spectral components in the range of 300 to 2000 Hz, however, not within the range up to 300 Hz. Signal properties are discussed with respect to different breathing types, as well as to the presence and the type of apneas. Principal component analysis of the event-based characteristics shows significant properties of the sound signal with respect to different types of apneas and different patient groups, respectively. The analysis reflects apneas with an obstructive segment and those with a central segment. In addition, aiming for an optimum detection of all three sound components, alternative regions on the thorax and on the neck were investigated on two subjects. The results suggest that the right thorax region in the seventh intercostal space and the neck are optimal regions. It is concluded that for patient assessment, extensive acoustic analysis offers a reduction in the number of required sensor components, especially with respect to compact home monitoring of apneas. [ABSTRACT FROM AUTHOR]

Discusses the respiratory functions of the intercostal muscles. Mechanisms of the respiratory effects in humans; Details on the distribution of neural drive to the intercostal muscles during breathing; Explanation on the interaction between inspiratory intercostals and other respiratory muscles.

Spinal deformity in the form of kyphosis or kyphoscoliosis occurs in most patients with Duchenne muscular dystrophy (DMD), a fatal X-linked disorder caused by an absence of the subsarcolemmal protein dystrophin. Mdx mice, which also lack dystrophin, show thoracolumbar kyphosis that progresses with age. We hypothesize that paraspinal and respiratory muscle weakness and fibrosis are associated with the progression of spinal deformity in this mouse model, and similar to DMD patients there is evidence of altered thoracic conformation and area. We measured kyphosis in mdx and age-matched control mice by monthly radiographs and the application of a novel radiographic index, the kyphotic index, similar to that used in boys with DMD. Kyphotic index became significantly less in mdx at 9 mo of age (3.58 ± 0.12 compared with 4.27 ± 0.04 in the control strain; P ≤ 0.01), indicating more severe kyphosis, and remained less from 10 to 17 mo of age. Thoracic area in 17-mo-old mdx was reduced by 14% compared with control mice (P ≤ 0.05). Peak tetanic tension was significantly lower in mdx and fell 47% in old mdx latissimus dorsi muscles, 44% in intercostal strips, and 73% in diaphragm strips (P ≤ 0.05). Fibrosis of these muscles and the longissimus dorsi, measured by hydroxyproline analysis and histological grading of picrosirius red-stained sections, was greater in mdx (P < 0.05). We conclude that kyphotic index is a useful measure in mdx and other kyphotic mouse strains, and assessment of paralumbar and accessory respiratory muscles enhance understanding of spinal deformity in muscular dystrophy. [ABSTRACT FROM AUTHOR]

This study aimed to examine whether changes in the activity of shoulder and neck muscles have consequences for the activation of primary breathing muscles. It further aimed to compare muscle loading levels of professional and student singers. Four professional opera singers participated in the study. Previous unpublished recordings of 4 to 16 student singers and one opera singer were included to allow comparison of EMG loading levels between student and professional singers. Electromyographic (EMG) recordings of trapezius (TR), sternocleidomastoideus (STM), intercostals (INT), rectus abdominis (RC) and the lateral abdominal muscles (OBL) were performed. EMG biofeedback (BF) was performed on TR and STM to lower the activity in these two muscles and the potential change in EMG activity of INT, RC and OBL were examined. Three singing tasks were performed: aria, sustained tones and extreme tones. Each task was performed three times with variation in volume or pitch. Following the first performance of the singing tasks, the BF session was carried out and muscle activity recorded in a repeat performance of the same tasks. The EMG activity levels of all muscles were compared before and after BF. We found no significant effect of reduced TR/STM activity on the activation of INT, RC and OBL. Professional opera singers activated the TR, INT, RC and OBL muscles to higher levels than the student singers did. Another finding was large inter-subject variation in muscle usage, showing an idiosyncratic composition of the muscle contribution to subglottal pressure. [ABSTRACT FROM AUTHOR]

STUDY DESIGN:: Intercostal nerve to spinal nerve root anastomosis in chronic spine-injured patients. OBJECTIVES:: To analyze the effectiveness of neurogenic bladder reinnervation in spinal cord-injured patients through artificial creation of sprouting (intercostal nerve to spinal nerve root anastomosis). SETTING:: Center of Neurosurgery, Moscow, Russia. Operations were performed by Professor A Livshits. (At present, Professor A Livshits is working at the Spinal Care Unit, Meir General Hospital, Kfar Saba, Israel.) METHODS:: A total of 11 patients with spinal cord injury of the L1 level were operated on in the late (chronic) stage. The neurological status and urodynamics were investigated before and 12 months after operation. A laminectomy from T11 to L3 was performed. Next, a neurolysis of the 11th and 12th intercostal nerves was carried out, at a distance of 20-21?cm, and transferred to the vertebral canal. The S2-S3 roots were then cut in their proximal portion and anastomosed end-to-end to the intercostal nerves. The results of urodynamic studies were calculated by the Wilcoxon signed rank test for comparison before and 12 months after operation. RESULTS OF URODYNAMIC STUDIES:: Bladder capacity (ml) before operation - 489±79, after operation - 350±39, urine volume (ml) before - 18.2±17, after - 306.4±39.8, residual urine (ml) before - 459±99.4, after - 50±11.8. Detrusor tone (rel. units) before - 0.6±1.5, after 1.2±0.2; voiding pressure (cmH2O) before - 4.4±5.2, after - 30.5±4.9. Force of detrusor contraction before - 5±5.8, after - 32.8±5.5. Sphincter resistance (cmH2O) before - 6.5±3.8, after - 21.1±4.2. Significant improvements in bladder function were observed during the 10th to 12th postoperative months. Restoration of reflex voiding occurred in all patients; in eight of the 11 paresthesic in the groin and scrotum and reappearance of the bulbocavernous, anal and cremasteric reflexes were noted. CONCLUSION:: These results suggest that a restitutive process occurs in the bladder under novel conditions of its nerve supply provided by the intercostal nerve and by new connections established between it and the bladder nerves. Spinal cord lesions that might benefit from nerve crossover surgery would be located at the conus, so functional intercostal nerves could be connected to sacral roots to bypass the injury in an attempt to restore central connections to the bladder.Spinal Cord (2004) 42, 211-217. doi:10.1038/sj.sc.3101574 [ABSTRACT FROM AUTHOR]

The coupling between the ribs and the lung in dogs increases with increasing rib number in the cranial part of the rib cage and then decreases markedly in the caudal part. The hypothesis was raised that this non-uniformity is primarily related to differences between the areas of the lung subtended by the different ribs, and in the current study we tested this idea by assessing the effects of passive lung inflation. Thus, by causing a descent of the diaphragm, inflation would expand the area of the lung subtended by the caudal ribs and improve the coupling between these ribs and the lung. The axial displacements of the ribs and the changes in airway opening pressure (Δ Pao) were measured in anaesthetized, pancuronium-treated, supine dogs while loads were applied in the cranial direction to individual rib pairs at functional residual capacity (FRC) and after passive inflation to 10 and 20 cmH2O transrespiratory pressure. In agreement with the hypothesis, inflation caused an increase inΔ Pao for ribs 9 and 10. The most prominent alteration, however, was a marked decrease inΔ Pao for ribs 2–8; at 20 cmH2O,Δ Pao for these ribs was only 30% of the value at FRC. Additional measurements indicated that this decrease inΔ Pao results partly from the increase in diaphragmatic compliance but mostly from the reduction in outward rib displacement. This alteration in the pattern of rib motion should add to the decrease in muscle length to reduce the lung expanding action of the external intercostal muscles at high lung volumes. [ABSTRACT FROM AUTHOR]

Examines the two mechanisms of intercostal muscle action on the lung. Effect of external factors on the mechanism of respiratory action of the intercostal muscles; Geometry of the ribs and intercostal muscle; Deetction of hamberger mechanism.

The technique of resuscitative transverse thoracotomy is foruse in case of circulatory arrest in the trauma patient. This technique, performed after orotracheal intubation, is initiated by a 5th intercostal space thoracostomy in each mid-axillary line. If the circulatory arrest is not caused by a tension pneumothorax, bilateral thoracotomies in the 5th intercostal spaces with transverse transsection of the sternum is performed. Middle vertical incision of the pericardium allows the evacuation of a cardiac tamponade. This wide surgical access has proved simple to perform, even by non experienced operators. It allows digital control of a heart wound, cross-clamping of the thoracic descending aorta or of pulmonary hilum, rapid perfusion of warm fluids through the right auricle and the performance of bimanual internal cardiac massage. [Copyright &y& Elsevier]

Abstract Spontaneous pneumothoraces (SP) are a common cause of presentation to emergency departments and subsequent hospitalization. In recent years there has been an increasing trend towards the use of small-bore pleural catheters (PC) rather than conventional large-bore intercostal catheters (ICC) in their initial management. To compare the effectiveness and complication rate of ICC and PC in the treatment of SP. A retrospective chart audit was conducted of 67 cases of SP admitted to the Royal Prince Alfred ­Hospital, Sydney, Australia, between 1 July 1997 and 30 June 2000. Demographic data were recorded, ­including: (i) patient age, (ii) smoking status, (iii) pneumothorax size, (iv) pneumothorax type and (v) aetiology. Outcome data relating to length of hos­pital stay (LOS) and treatment failure rates and comp­lications of treatment devices were also recorded. Successful pneumothorax resolution was achieved ( P = 0.72) in 20 of the 31 (65%) patients initially treated with a ICC, and in 26 of the 36 (72%) patients treated with a PC. The mean LOS in the ICC and PC group was 7 days and 5 days, respectively ( P = 0.11). The complication rates in the PC and ICC group were 25% and 10%, respectively ( P = 0.13), and the recurrence rates for each group were 17% and 6% ( P = 0.20), respectively. However, the combined rate of complications and pneumothorax recurrence within 2 months was 42% in those initially treated with PC, compared with 16% in those treated with ICC ( P = 0.04). PC were as effective as ICC in treating SP in terms of initial pneumothorax resolution and LOS. There were trends towards higher complication and recurrence rates in those treated with PC, but individ­ually these results did not reach statistical significance. However, the combined rate of complications and pneumo­thorax recurrence was significantly higher in those patients treated with the PC than in those treated with ICC. (Intern Med J 2003; 33: 495−499) [ABSTRACT FROM AUTHOR]

In animals, high-intensity unilateral stimulation of the phrenic nerve results in short-latency inhibition of phrenic and intercostal nerve activity bilaterally. This study provides the first demonstration in human subjects of a short-latency inhibitory response in the contralateral scalene, parasternal intercostal and diaphragm muscles to single stimuli delivered at cervical level to the phrenic nerve. Electromyographic (EMG) responses were recorded with intramuscular and surface electrodes. An inhibitory response with an onset latency of ∼35 ms followed by a long-latency excitatory response at ∼100 ms were observed in the three inspiratory muscles. The inhibition was evident in single trials, averaged EMG, histograms of the discharge of single motor units, and even when the phrenic nerve stimulus intensity was relatively low. Thus, the inhibition may be mediated by large-diameter muscle afferents. The latency of this potent inhibitory response to contralateral phrenic nerve stimulation is too long to be mediated via a simple spinal circuit and may involve a brainstem projection. [Copyright &y& Elsevier]

Background: Pain following thoracotomy is frequently associated with clinically important abnormalities of pulmonary function. The aim of the current study was to compare the efficacy of continuous thoracic epidural analgesia (EDA) to continuous intercostal (IC) block for postoperative pain and pulmonary function in a prospective, randomized, double-blinded clinical trial.Methods: Fifty patients undergoing lung lobectomy for malignancies were randomized into two groups (25/group). Respiratory function (forced vital capacity, forced expiratory volume per 1 s/forced vital capacity, maximum midexpiratory flow rate, peak expiratory flow rate) were evaluated preoperatively, within 4 h after the operation and on the first postoperative day. Visual analog scale (VAS: 0-10) scores were evaluated four-hourly for 20 h.Results: The VAS scores were significantly lower in the EDA versus IC group at the 4th, 8th, and 12th h of observation (mean +/- SD) 5.5 +/- 2.9 vs. 7.3 +/- 2.2 P = 0.04; 4.1 +/- 2.1 vs. 5.1 +/- 2.9 P = 0.02; 3.6 +/- 1.9 vs. 5.2 +/- 2.4 P = 0.01, respectively. Respiratory function parameters deteriorated significantly in both groups (P < 0.001) with no significant difference between the groups. Only one major adverse effect was detected: one patient suffered from rib osteomyelitis after intercostal cannulation and healed following surgical repair.Conclusions: The results of the present study show that following thoracotomy in the early postoperative period continuous EDA is a better pain relieving method than continuous IC block, as indicated by the VAS scores. [ABSTRACT FROM AUTHOR]

To investigate the role of neurotransmitter secretion in the development and stabilization of synapses, the innervation of the diaphragm and intercostal muscles was studied in munc18-1 null mutant mice, which lack regulated secretion. We found that this mutant is completely devoid of both spontaneous and evoked neuromuscular transmission throughout embryonic development. At embryonic day (E) 14, axonal targeting and main branching of the phrenic nerve were normal in this mutant, but tertiary branches were elongated and no terminal branches were observed at this stage, in contrast to control littermates. Acetylcholinesterase staining was observed in the endplate region of mutant muscle from E14 onwards, but not as dense and confined to spots as in controls. Acetylcholine receptor staining was also present in the endplate region of the mutant muscle. In this case, the staining density and the concentration in spots (clusters) were similar to controls, but the distribution of these clusters was less organized. Starting at E15, some receptor clusters co-localized with nerve terminal staining, suggesting synapses, but most clusters remained a-neural. Electron microscopical analysis confirmed the presence of synaptic structures in the mutant. Between E14 and birth, the characteristic staining pattern of nerve branches gradually disappeared in the mutant until, at E18, an elaborate meshwork of nerve fibers with no apparent organization remained. In the same period, most of the motor neuronal cell bodies in the spinal cord degenerated. In contrast, sensory ganglia in the dorsal root showed no obvious degeneration. These data suggest that regulated secretion is not essential for initial axon path finding, clustering of acetylcholine receptors, acetylcholinesterase or the formation of synapses. However, in the absence of regulated secretion, the maintenance of the motor neuronal system, organization of nerve terminal branches and stabilization of synapses is impaired and a-neural postsynaptic elements persist. [Copyright &y& Elsevier]

During l-DOPA-induced fictive spinal locomotion rhythmic activities in nerves to internal intercostal and external oblique abdominal muscles and in phrenic and sympathetic nerves were observed which were always coordinated with locomotor activity in forelimb and hindlimb muscle nerves. A periodicity with longer lasting tonic phases could be induced by cutaneous nerve stimulation or asphyxia. This activity was observed in limb motor nerves as well as in respiratory motor and sympathetic nerves. A slow independent activity of the phrenic and intercostal nerves or the sympathetic nerves, which could be related to a normal respiratory rhythm or independent sympathetic rhythms was not observed. The findings indicate that during fictive spinal locomotion the activity of spinal rhythm generators for locomotion also projects onto respiratory and sympathetic spinal neurones. [Copyright &y& Elsevier]

The traditional view that all parts of the ribs originate from the sclerotome of the thoracic somites has recently been challenged by an alternative view suggesting that only the proximal rib derives from the sclerotome, while the distal rib arises from regions of the dermomyotome. In view of this continuing controversy and to learn more about the cell interactions during rib morphogenesis, this study aimed to reveal the precise contributions made by somitic cells to the ribs and associated tissues of the thoracic cage. A replication-deficient lacZ-encoding retrovirus was utilized to label cell populations within distinct regions of somites 19–26 in stage 13–18 chick embryos. Analysis of the subsequent contributions made by these cells revealed that the thoracic somites are the sole source of cells for the ribs. More precisely, it is the sclerotome compartment of the somites that contributes cells to both the proximal and distal elements of the ribs, confirming the traditional view of the origin of the ribs. Results also indicate that the precursor cells of the ribs and intercostal muscles are intimately associated within the somite, a relationship that may be essential for proper rib morphogenesis. Finally, the data from this study also show that the distal ribs are largely subject to resegmentation, although cell mixing may occur at the most sternal extremities. [Copyright &y& Elsevier]

Objective: We examined in rabbits the effects of more than 48 h of mechanical ventilation on the contractile properties and fiber type adaptations of the respiratory muscles.Design and Setting: Experimental prospective study in a university laboratory.Animals and Interventions: Nineteen rabbits were randomly allocated to two groups: control (n=10) or mechanically ventilated (MV; n=9) for 51+/-3 h.Measurements and Results: Respiratory muscles contractile properties were analyzed before and after a fatigue protocol using in vivo isometric 1-s tetanic contraction characteristics in both muscles: peak tetanic force, contraction time, relaxation time, and total contraction time. Both muscle fiber type proportions, diameter, and cross-sectional areas were measured using ATPase staining. The MV rabbits showed significant weight loss in both muscles, accompanied by a reduced peak tetanic force (9.96+/-3.2 vs. 7.44+/-2.2 N for diaphragm of control and MV animals respectively), fatigue resistance index, and increased relaxation time (57.5+/-8.7 vs. 85.8+/-9.4 ms for diaphragm of control and MV animals) and contraction time. These impairments in the MV group worsened after the fatigue runs. Both muscle showed a significant atrophy of type IIa and IIb fibers but a stability in type I fibers cross-sectional area.Conclusions: Mechanical ventilation in rabbits produces alterations in contractile properties of the diaphragm and 5th external intercostal muscle, increases both muscles fatigue, and promotes atrophy of type II fibers. [ABSTRACT FROM AUTHOR]

Attention coefficient and propagation speed of intercostal tissues were estimated from chest walls removed postmortem (pm) from 15 5.3±2.3-day-old, 19 31±6day-old, and 15 61±3-day-old crossbred pigs. These ultrasonic propagation properties were determined from measurements through the intercostal tissues, from the surface of the skin to the parietal pleura. The chest walls were placed in a 0.9% sodium chloride solution, sealed in freezer bags, and stored at -15°C prior to measurements. When evaluated, chest-wall storage time ranged between 1 and 477 days pro. All chest walls were allowed to equilibrate to 22°C in a water bath prior to evaluation. There was an age dependency of the intercostal tissue propagation speed, with the speed increasing with increasing age. The attenuation coefficient of intercostal tissue was shown to be independent of the age of the pig at the discrete frequencies of 3.1 and 6.2 MHz. For pig intercostal tissues, the estimated attenuation coefficient over the 3.1-9.2 MHz frequency range was A = 1.94f[sup 0.90] where A is in decibels per centimeter (dB/em) and f is the ultrasonic frequency in megahertz. In order to determine if there was an effect of storage time pm on estimates of attenuation coefficient, a second experiment was conducted. Five of the youngest pig chest walls measured on day 1 pm in the first experiment were stored at 4°C prior to the first evaluation then stored at -15°C before being measured again at 108 days pro. There was no difference in the estimated intercostal tissue attenuation coefficient as a function of storage time pm. [ABSTRACT FROM AUTHOR]

Attenuation coefficient and propagation speed of intercostal tissues were estimated as functions of temperature (22, 30, and 37°C) from fresh chest walls from eight 10- to 11-week-old female Sprague-Dawley (SD) rats, eight 21- to 24-week-old female Long-Evans (LE) rats, and ten 6- to 10-week-old mixed sex Yorkshire (York) pigs. The primary purpose of the study was to estimate the temperature dependence of the intercostal tissue's attenuation coefficient so that accurate estimates of the in situ (at the pleural surface) acoustic pressure levels could be made for our ultrasound-induced lung hemorrhage studies. The attenuation coefficient of intercostal tissue for both species was independent of the temperature at the discrete frequencies of 3.1 MHz (-0.0076, 0.0065, and 0.016 dB/cm/°C for SD rats, LE rats, and York pigs, respectively) and 6.2 MHz (-0.015, 0.014, and 0.014 dB/cm/°C for SD rats, LE rats, and York pigs, respectively). However, the temperature dependent regressions yielded a significant temperature dependency of the intercostal tissue attenuation coefficients in SD and LE rats (over the 3.1 to 9.6 MHz frequency range); there was no temperature dependency in York pigs (over the 3.1 to 8.6 MHz frequency range). There was no significant temperature dependency of the intercostal tissue propagation speed in SD rats; there was a temperature dependency in LE rats and York pigs (-0.59, -1.0, and -2.9 m/s/°C for SD rats, LE rats, and York pigs, respectively). Even though the attenuation coefficient's temperature dependency was significant from the linear regression functions, the differences were not very great (-0.040 to -0.13, 0.011 to 0.18, and 0.055 to 0.10 dB/cm/°C for SD rats, LE rats, and York pigs, respectively, over the data frequency range). These findings suggest that it is not necessary to determine the attenuation coefficient of intercostal tissue at body temperature (37°C), but rather it is sufficient to determine the... [ABSTRACT FROM AUTHOR]

Abstract Recent surveys have uncovered major variations in key aspects of intercostal drain management, suggesting that decisions are being made on individual preferences without resorting to sound evidence. We provide an up-to-date review of the best practice with evidence-based recommendations and expert consensus views. The following aspects of chest drain management have been addressed: indications for drainage, insertion technique, complications, management of an indwelling chest drain, indications and technique for removal. The emphasis in this review is that safe intercostal drain practice relies upon adherence to a few important principles. Furthermore, when in doubt, particularly with a complex thoracic problem, one should seek prompt specialist advice. [ABSTRACT FROM AUTHOR]

Objective: Previous work has suggested that intercostal nerve injury is a major factor in the aetiology of chronic postthoracotomy pain. The aim of this study was to establish if there was identifiable intercostal nerve injury during thoracotomy. Methods: Intercostal nerves were stimulated and motor evoked potentials were recorded from intercostal muscles in 13 patients undergoing thoracotomy. Measurements were taken before and after entering the pleural space, after removal of the rib retractor and after intercostal space closure. Results: Intercostal nerves functioned normally before and after entering the pleural space. After the rib retractor was removed, there was a total conduction block in the nerve immediately above the incision in every patient. In the nerves above this, six had a total block, one a partial block and three had normal conduction. There was a total conduction block in the nerve immediately below the incision in all but one patient. Of the nerves below this, four had a total block, two a partial block and three had normal conduction. In the cases of total conduction block, there was either a discrete block at the level of the distal end of the rib retractor or impairment throughout the whole nerve. Intercostal space closure did not injure any previously uninjured nerve. In a solitary patient where rib retraction was not employed, there was no impairment of the intercostal nerves throughout the operation. Conclusions: This study demonstrates for the first time that intercostal nerve injury occurs routinely due to rib retraction during thoracotomy. We believe that it may be an important step toward understanding the cause of postthoracotomy neuralgia. [Copyright &y& Elsevier]