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PubMedDate not supplied

Determination of the length and position of the lower oesophageal sphincter (LOS) by correlation of external measurements with combined radiographic and manometric estimations in the cat.

Fifty DSH cats were studied radiographically and a highly significant linear correlation was found between the length of the oesophagus measured to the diaphragmatic line on the radiographs and the externally measured distance from the lower jaw incisor teeth to the anterior border of the head of 10th rib. A subsequent manometric study utilizing this correlation in 40 cats suggests that the functional lower oesophageal sphincter (LOS) is situated almost at the level of the diaphragm in the cat. Significant differences were found between the length of the LOS in cats anaesthetized with ketamine compared to alphaxalone-alphadolone or xylazine-ketamine-atropine. The mean lengths of the LOS was 1.42 +/- 0.3 cm. The findings of this study indicate that external measurements can be used to position catheters for accurate oesophageal manometry in the cat.

Animals↗
PubMed1997

No-cut thoracoscopic lung plication: a new technique for lung volume reduction surgery.

BACKGROUND: Lung volume reduction surgery (LVRS) using a linear cutting stapler or laser ablation via median sternotomy or thoracoscopy is a current therapy for symptomatic emphysema. The primary causes of morbidity and mortality (as high as 20%) are existing comorbidities and prolonged air leaks secondary to visceral pleural division. We report a novel technique using minimally invasive techniques designed to achieve volume reduction while preserving the visceral pleura. A novel lung grasper and a knifeless stapler are used to permanently plicate lung tissue without cutting visceral pleura. STUDY DESIGN: This prospective analysis involves a consecutive series of patients who had LVRS using this method. Between May 1995 and September 1996, 32 patients underwent 50 unilateral, staged bilateral, or bilateral thoracoscopic lung plication procedures. The indications for LVRS were standard; they included severe limiting dyspnea (forced expiratory volume in one second [FEV1] = 0.68 +/- 0.05), hyperinflated lungs with flattened diaphragms on chest x-ray, and diffuse emphysema seen on chest computed tomography scan. Ventilation and perfusion scanning was used to identify potential ventilation and perfusion mismatch target areas of lung for plication. RESULTS: The right lung was plicated first in 25 of 32 patients (78%), and upper lobe plications predominated (77%). A mean of 9.3 +/- 0.8 staple firings were used for each unilateral plication procedure. There were no perioperative deaths. Two patients (4%) required axillary thoracotomies to repair air leaks. Mean chest tube duration was 6.3 +/- 0.5 days. Median hospital stay was 7 days (range 3-15). An Intensive Care Unit stay was required following 8 procedures (17%). Postoperative morbidity occurred in 18 (39%) of 46 procedures, including 5 cases of atrial fibrillation and 4 persistent (> 7 days) air leaks. A minimum 2 month followup was available for 22 patients (32 of 46 procedures), demonstrating a clear chest x-ray with significant improvement in ipsilateral diaphragmatic contour. Twelve patients had unilateral reduction, and 10 patients had bilateral reduction in either a staged (n = 7) or sequential at one operation (n = 3) fashion. Twenty-five (78%) of 32 procedures were associated with improved pulmonary function, with a mean increase in FEV1, in patients in this subgroup of procedures, of 43 +/- 7% for each ipsilateral plication at a mean followup of 3.8 +/- 0.5 months. For the entire group of 32 procedures, the mean improvement in measured FEV1 was 29 +/- 7%. Supplemental oxygen requirement was significantly reduced in 9 of 16 patients following plication. CONCLUSION: These data suggest that minimally invasive surgical techniques coupled with a no-cut lung plication can achieve significant lung volume reduction with favorable postoperative morbidity and mortality. Lung plication appears to hold promise as an alternative technique of LVRS.

Humans↗
PubMed2003

[Respiratory physiotherapy in lung diseases].

Functionally COPD is characterized by a reduction in airflow and an increase in dead space. Physical therapy and breathing training is designed to increase tidal volume, decrease respiratory rate and sense of dysponea. The respiratory exercises include controlled breathing, diaphragmatic and pursed-lip breathing. Postural drainage has, in most parts of the world, been replaced by airway clearance regimens that include forced expiratory manoeuvres or technique of breathing at different airflow and lung volume. Percussions and external or internal vibrations are seldom justified in adults. About instrumental chest physiotherapy with positive expiratory pressure support, the literature is confusing except for non invasive ventilation in acute stages. Dyspnoea, impaired exercise tolerance and reduced quality of life are common complaints in patients with chronic obstructive pulmonary disease. The efficacy of pulmonary rehabilitation has been strongly established by randomized controlled trials as reported by recent meta-analysis. The training intensity is of key importance. High-intensity training is feasible even in patients with more advanced COPD. There is substantial evidence that lower extremity endurance training should be included in the rehabilitation programs. There are beneficial effects of upper extremity endurance and strength training. Ventilatory muscle training may be considered in individual patients. Pulmonary rehabilitation programs must also be comprehensive and flexible to address each patients' need and include smoking cessation, optimal medical treatment, nutritional intervention, psychosocial support and health education. The maintenance of benefits after pulmonary rehabilitation is possible with minimal maintenance of activity.

Breathing Exercises↗
PubMed1998

Expression of clara cell 10-kDa protein (CC10) in congenital diaphragmatic hernia.

Clara cell 10 kDa protein (CC10) has been thought to be fairly specific to Clara cells and a major secretory protein that is both synthesized and released from Clara cells. In the present study, morphometric analyses of the immunohistochemical expression of CC10 were carried out on the bronchioles of human neonates with congenital diaphragmatic hernia (CDH) and then compared with morphometric analyses from a gestationally and postnatally age-matched control group in order to clarify the immaturity of Clara cells in CDH lungs. No difference was found in CC10 expression between the affected side and the unaffected side of the lungs in the CDH group. However, compared with the lungs of the control group, the CDH group showed a significant decrease in CC10 expression, namely, the ratio of CC10-positive cells per bronchiole, per unit perimeter of bronchiole, and per unit bronchiolar surface area. These results suggest that in the lungs of CDH cases, a possible delay in either functional maturation or the development of CC10 synthesis by the bronchioles may exist, and this retardation of functional maturation of the airway is also considered to play a role in the postnatal respiratory insufficiency observed in CDH patients.

Bronchi↗
PubMed1977

Diaphragmatic fatigue in man.

The time required (tlim) to produce fatigue of the diaphragm was determined in three normal seated subjects, breathing through a variety of high alinear, inspiratory resistances. During each breath in all experimental runs the subject generated a transdiaphragmatic pressure (Pdi) which was a predetermined fraction of his maximum inspiratory Pdi (Pdimax) at functional residual capacity. The breathing test was performed until the subject was unable to generate this Pdi. The relationship between Pdi/Pdimax and tlim was curvilinear so that when Pdi/Pdimax was small tlim increased markedly for little changes in Pdi/Pdimax. The value of Pdi/Pdimax that could be generated indefinitely (Pdicrit) was around 0.4. Hypoxia appeared to have no influence on Pdicrit, but probably led to a reduction in tlim at Pdi greater than Pdicrit for equal rates of energy consumption. Insofar as the behavior of the diaphragm reflects that of other respiratory muscles it appears that quite high inspiratory loads can be tolerated indefinitely. However, when the energy consumption of the respiratory muscles exceeds a critical level, fatigue should develop. This may be a mechanism of respiratory failure in a variety in a variety of lung diseases.

Diaphragm↗
PubMed2004

Consequences of thyroxine treatment on diaphragm and EDL of normal and dystrophic hamsters.

Previously administration of thyroxine (T4) to dystrophic hamsters improved ventilation and slowed the progression of the disease. We hypothesized that the normalization of ventilation in these animals was due to T4 improving structural and functional characteristics of the diaphragm. In the present study, contractile characteristics of the diaphragm and the extensor digitorum longus (EDL) from normal and dystrophic hamsters were evaluated after two months of T4 treatment. Compared to their placebo-treated counterparts, diaphragms and EDLs of T4-treated normal hamsters showed increased optimal muscle lengths and twitch tension, decreased contraction times and increased fatigability. T4-treatment in dystrophic hamsters showed only an increase in diaphragmatic twitch tension development. Force-frequency curves before treatment were generally higher for the normal compared to dystrophic diaphragms and EDLs. T4 administration only increased the force in normal diaphragms at the lower frequencies and in the EDLs at the higher frequencies. Although T4 serum levels were increased in both T4-treated groups, triiodothyronine (T3) was much lower in the dystrophic compared to normal hamsters, suggesting that conversion of T4 to T3 was reduced in dystrophic hamsters. We conclude that the limited functional changes in the diaphragms of T4-treated dystrophic hamsters cannot account for the marked improvement in ventilation previously reported.

Animals↗
PubMed2004

Long-term observations of patients with infantile spinal muscular atrophy with respiratory distress type 1 (SMARD1).

We describe 6 unrelated patients affected by infantile spinal muscular atrophy with respiratory distress type 1 (SMARD1) with prolonged survival upon mechanical ventilation (4.5-11 years), which has not been reported before. Biallelic mutations in the IGHMBP2 gene proved the diagnosis of SMARD1 in all patients. Disease onset was in the first 2 months in the described patients, starting with generalised hypotonia, failure to thrive, and early breathing difficulties. Diaphragmatic palsy was diagnosed and permanent ventilation was initiated 2-8 months after onset. Within months a more distal muscular atrophy became evident associated with joint contractures (talipes), hand drops, and fatty finger pads. Motor development remained minimal, loss of function was observed within the first year after which no further progression was recorded. Voiding dysfunction with reflux nephropathy was observed in 3 patients and has not been reported before. Further evidence of autonomic nerve dysfunction resulting in cardiac arrhythmia, hypertension, and excessive sweating was given in 2 patients. Investigative results were largely compatible with those obtained in classic SMA. However, neurogenic atrophy muscle was more pronounced in distal muscles, if examined, and there was evidence of peripheral nerve involvement at least in some patients.

Age Factors↗
PubMed1998

Phrenic nerve injury following cardiac surgery: a review.

Phrenic nerve injury following cardiac surgery is variable in its incidence depending on the diligence with which it is sought. Definitive studies have shown this complication to be related to cold-induced injury during myocardial protection strategies and possibly to mechanical injury during internal mammary artery harvesting. The consequences are also variable and depend to a large extent on the underlying condition of the patient, particularly with regard to pulmonary function. The response of the patient may range from an asymptomatic radiographic abnormality to severe pulmonary dysfunction requiring prolonged mechanical ventilation and other associated morbidities and even mortality. Two cases are presented to demonstrate the variability in clinical responses to diaphragmatic dysfunction secondary to phrenic nerve injury from cardiac surgery. In addition, treatment strategies are reviewed including early tracheostomy and diaphragmatic plication, which appear to be the most effective options for patients who are compromised by phrenic injuries.

Cardiac Surgical Procedures↗
PubMed1999

Primary hypoparathyroidism in two horses.

Two Thoroughbred horses were presented with various clinical signs which included sweating, agitation, muscle twitching and synchronous diaphragmatic flutter. These signs were associated with profound hypocalcaemia. A diagnosis of primary hypoparathyroidism was made on the basis of low serum ionised calcium concentration, hyperphosphataemia and markedly reduced serum immunoreactive parathyroid hormone concentrations in the presence of normal renal function. Treatment with a combination of intravenous calcium and subsequently oral calcium, magnesium and a vitamin D analogue (dihydrotachysterol) for up to 65 days resulted in complete remission of clinical signs. Horse 1 was euthanased 12 months after the initial recognition of signs. Results of necropsy were unremarkable apart from an absence of detectable parathyroid tissue. Horse 2 returned to athletic activities while receiving only maintenance doses of oral calcium carbonate.

Animals↗
PubMed1991

Role of theophyllines in severe chronic obstructive pulmonary disease.

Theophyllines are effective bronchodilators, but have other respiratory effects which may be beneficial in patients with chronic obstructive pulmonary disease. These effects include increased diaphragmatic contractility, central respiratory stimulation and anti-inflammatory actions. Some controversy exists however on the precise role of these effects in the clinical setting. We examined the effects of a long-acting theophylline preparation (Uniphyllin Continus) on pulmonary function, and on ventilation and gas exchange during rest, sleep and exercise in a group of 12 patients with severe (FEV1 32 +/- 8.3% predicted), but stable chronic obstructive pulmonary disease. The study was randomised, placebo-controlled, and double-blind in nature. Preliminary analysis of the data indicates a significant improvement in the degree of hyperinflation and gas-trapping with theophylline, and oxygen levels were improved during rest, sleep and exercise while on theophylline. These findings confirm a beneficial effect of theophylline in such patients.

Bronchi↗
PubMedDate not supplied

Pulmonary involvement in systemic lupus erythematosus.

In the course of an ample study of collagen diseases carried out in the "N. Gh. Lupu" Institute of Internal Medicine--Bucharest over a long period, a group of 608 patients with systemic lupus erythematosus (SLE) hospitalized between 1974 and 1986 formed the object of the present study. Of these patients 18% presented pulmonary alterations due to SLE and 3.9% lung diseases of other etiology. The types of pulmonary involvement due to SLE were: pleurisy, interstitial pneumonia, diaphragmatic myopathy. Latent pulmonary damage could also be diagnosed in 8 patients. Most of the patients (94.1%) were females and had been hospitalized several times. Concomitantly with pulmonary damage other organ involvements have also been observed. Complex investigation of respiratory function performed in a selected group of patients revealed: restrictive syndrome, decrease of the gas transfer factor, increase of elastic recoil, hypoxemia on exercise. In most of the cases (92%) the pulmonary diseases had a chronic evolution. The treatment used was corticosteroids in 60% of the cases investigated.

Adolescent↗
PubMed1986

The relation of inspiratory effort sensation to fatiguing patterns of the diaphragm.

Tension in the respiratory muscles and the subsequent intrathoracic subatmospheric pressure swing plays a role in respiratory effort sensation. However, the role of a diaphragmatic fatiguing process in the genesis of this sensation has not been examined. Therefore, we studied the effect of fatiguing contractions of the diaphragm on inspiratory effort sensation (IES) in 6 normal male subjects during inspiratory resistive loading. Four diaphragmatic fatiguing and 4 diaphragmatic nonfatiguing patterns were developed for each subject. These 8 patterns were imposed in random order for 10 breaths (50 s) with duty cycle and tidal volume fixed. The presence or absence of a diaphragmatic fatiguing process was confirmed by analysis of the high to low ratio of the electromyographic signal from an esophageal electrode. Subjects scored their IES immediately after each run using a modified Borg scale. There was a very strong correlation between IES and esophageal pressure (Pes) expressed as a percentage of maximal inspiratory esophageal pressure (Pes/Pesmax %) (r = 0.88, p less than 0.001). However, IES was independent of the presence of a diaphragmatic fatiguing pattern. Furthermore, there was no difference in the slope or intercept of the regression lines relating IES to Pes/Pesmax % when fatiguing and nonfatiguing runs were analyzed separately. We conclude that the severity of IES during resistive loading held for 50 s is independent of the development of diaphragmatic fatigue.

Adult↗
PubMed1990

Tracheobronchial clearance in patients with bilateral diaphragmatic weakness.

Tracheobronchial clearance was measured in seven patients with bilateral diaphragmatic weakness using a noninvasive objective radioaerosol technique. The data were compared with those from seven healthy nonsmoking control subjects matched for physical characteristics and studied under the same experimental conditions; the control subjects were drawn from a data bank of healthy subjects and were matched to the patients for age, sex, and the initial distribution of their radioaerosol deposition. Pulmonary function indices (FEV1, FVC, PEFR, and MMFR25-75) for the patients were all significantly (p less than 0.01) reduced compared with those for the control subjects. The initial topographic distribution of the radioaerosol within the lungs of the patients and control groups was similar: alveolar deposition [mean (SD)] was 36.4 (6.7) versus 41.0 (4.0)%, and penetration index was 0.56 (0.08) versus 0.56 (0.03), respectively. Tracheobronchial clearance of deposited radioaerosol over a 6-h observation period after inhalation showed a marked reduction (p less than 0.02) in the patients: area under the clearance curve (between zero and 6 h) was 262 (80)% h for the patients and 142 (41)% h for the healthy control subjects. These data suggest that in patients with bilateral diaphragmatic weakness, mucociliary clearance is depressed, or that reduced mechanical movement of the lungs can itself impair clearance of secretions from the lungs. Impaired clearance from either cause may contribute to an increased incidence of chest infections in severe respiratory muscle weakness.

Adult↗
PubMed1996

The effect of exercise on diaphragmatic activation in horses.

Horses chronically-instrumented with costal diaphragmatic electromyographic electrodes were studied during exercise while unencumbered by a breathing mask. Exercise-associated changes in esophageal (Pes), gastric (Pga) and transdiaphragmatic (Pdi) pressures were measured and related to diaphragmatic electromyographic activity (CS EMG) and to left forelimb impact. In all breaths examined, CS EMG always coincided with decrements in Pes. For all exercise trials, linear increases in CS EMG, Pga and Pdi and linear decreases in Pes, as a function of exercise intensity, always occurred. During all gaits, breathing frequency (fR) was entrained with stride frequency (fS) one for one. However, a constant phase-coupling relationship between fR and fS, observed when horses cantered and galloped, was absent when horses walked or trotted. We conclude that biomechanical forces contribute minimally to ventilation in exercising horses, that the diaphragm is always phasically active during each breath and its total electrical activity and mechanical output are proportional to the exercise hyperpnea.

Animals↗
PubMed1996

Clinical correlates of an elevated diffusing capacity for carbon monoxide corrected for alveolar volume.

The diffusing capacity for carbon monoxide is partially dependent on lung volume at which it is measured. As a consequence, the diffusing capacity for carbon monoxide is often indexed to the simultaneously measured lung volume (VA), giving rise to the term DL/VA. This reflects the diffusing capacity of carbon monoxide per unit area of lung parenchyma. The authors investigated the pulmonary function of 18 patients who had an elevated DL/VA in order to identify factors that could account for this abnormality. Sixteen of the 18 had a reduction in vital capacity. The vital capacity was reduced because of obesity, pleural disease, and diaphragmatic dysfunction. Eight of nine patients with a body mass index > 30 kg/m2 had a reduction in vital capacity. On the basis of these findings, we believe that an elevated DL/VA should alert the physician to the possibility of 1) an increase in pulmonary capillary blood volume (Vc) (obesity, polycythemia, negative pleural pressure), and 2) reduced VA that does not directly affect the pulmonary capillary bed (pleural disease, neuromuscular disease).

Adult↗