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At least 667 records · Page 37Linked to original sources
PubMed1997

Concomitant cardiac and pulmonary operation. Pulmonary mechanics and outcome of phrenic nerve injury.

OBJECTIVE: We describe the postoperative respiratory failure due to the phrenic nerve injury in the setting of concomitant cardiac and pulmonary operation. EXPERIMENTAL STUDY: Prospective study. SETTING: Department of Cardiac and Thoracic Surgery Osaka University Medical School. PATIENTS AND INTERVENTIONS: From January 1984 to December 1993, 5 patients (1.4%) underwent the concomitant cardiac and pulmonary operation out of 359 patients who received surgical treatment for lung cancer at our institution. MEASURES AND RESULTS: Three (60%) out of 5 patients required prolonged mechanical ventilation despite the absence of cardiac complication, lung edema or pneumonia. Diaphragm function and work of breathing were measured in two patients before and after weaning from mechanical ventilation. Phrenic nerve dysfunction was consistent with the result that trans-diaphragmatic pressure (delta Pdi) was low, a ratio of gastric to esophageal pressure swing (delta Pga/delta Pes) was abnormally negative, and work of breathing (WOB) was high. Phrenic nerve function restored associated with clinical improvement. CONCLUSIONS: Diaphragm dysfunction and an increase in work of breathing may be potential causes of respiratory failure in patients after concomitant cardiac and pulmonary operation. This compromise in respiratory mechanics should not be overlooked in the postoperative care, which may lead to the best management in postoperative respiratory care.

Aged↗
PubMed2002

Role of heme oxygenases in sepsis-induced diaphragmatic contractile dysfunction and oxidative stress.

Heme oxygenases (HOs), essential enzymes for heme metabolism, play an important role in the defense against oxidative stress. In this study, we evaluated the expression and functional significance of HO-1 and HO-2 in the ventilatory muscles of normal rats and rats injected with bacterial lipopolysaccharide (LPS). Both HO-1 and HO-2 proteins were detected inside ventilatory and limb muscle fibers of normal rats. Diaphragmatic HO-1 and HO-2 expressions rose significantly within 1 and 12 h of LPS injection, respectively. Inhibition of the activity of inducible nitric oxide synthase (iNOS) in rats and absence of this isoform in iNOS(-/-) mice did alter sepsis-induced regulation of muscle HOs. Systemic inhibition of HO activity with chromium mesoporphyrin IX enhanced muscle protein oxidation and hydroxynonenal formation in both normal and septic rats. Moreover, in vitro diaphragmatic force generation declined substantially in response to HO inhibition both in normal and septic rats. We conclude that both HO-1 and HO-2 proteins play an important role in the regulation of muscle contractility and in the defense against sepsis-induced oxidative stress.

Animals↗
PubMed2003

Midazolam-induced muscle dysfunction and its recovery in fatigued diaphragm in dogs.

Midazolam, widely used for sedation and anesthesia, decreases contractility in nonfatigued diaphragm; however, its effects on contractility in fatigued diaphragm that are implicated as a cause of respiratory failure have not been established. We therefore studied the effects of midazolam on diaphragm muscle function and recovery in fatigued diaphragm. Dogs were divided into three groups of eight each. In each group, diaphragmatic fatigue was induced by intermittent supramaximal bilateral electrophrenic stimulation at a frequency of 20-Hz stimulation for 30 min. When fatigue was established, Group I received no study drug; Group II was infused with a sedative dose (0.1 mg x kg(-1) x h(-1)) of midazolam; and Group III was infused with an anesthetic dose (0.5 mg x kg(-1) x h(-1)) of midazolam. We assessed diaphragm muscle function (contractility and electrical activity) by transdiaphragmatic pressure (Pdi) and integrated electrical activity of the diaphragm (Edi). In the presence of fatigue, Pdi at low-frequency (20-Hz) stimulation decreased from baseline values (P < 0.05), Pdi at high-frequency (100-Hz) stimulation did not change, and Edi to each stimulus did not change. With an infusion of midazolam, in Groups II and III, Pdi at both stimuli and Edi at 100-Hz stimulation decreased from fatigued values (P < 0.05). The decrease in Pdi and Edi was more in Group III than in Group II (P < 0.05). At 60 min after the cessation of midazolam administration, in Group II, Pdi and Edi recovered from midazolam-induced values (P < 0.05) and returned to fatigued values. In Group III, Pdi and Edi did not change from midazolam-induced values. We conclude that midazolam causes, in a dose-related manner, diaphragm muscle dysfunction in fatigued canine diaphragm and that at a sedative dose, but not at an anesthetic dose, midazolam does not delay its recovery.

Anesthetics, Intravenous↗
PubMed2000

Antenatal dexamethasone improves atrial natriuretic peptide receptors in hypoplastic lung in nitrofen-induced diaphragmatic hernia in rats.

Atrial natriuretic peptide (ANP) plays a major role in electrolyte and volume homeostasis through potent biological effects including vasorelaxation, bronchorelaxation, lung permeability, and clearance. There are two distinct biochemical and functional classes of ANP receptors, guanylate cyclase receptor (GC-R) and clearance receptors (clearance-R). Two subtypes of GC-R have been described, GCA-R and GCB-R. Antenatal glucocorticoid therapy (AGT) has been demonstrated to improve pulmonary immaturity and abnormal structure of pulmonary arteries in animal models of congenital diaphragmatic hernia (CDH). The aim of this study was to investigate the effect of antenatal glucocorticoid administration on the ANP system in nitrofen-induced CDH hypoplastic lung in rats. A CDH model was induced in pregnant rats following administration of nitrofen on day 9.5 of gestation. Dexamethasone (Dex) was given intraperitoneally on days 18.5 and 19.5; cesarean section was performed on day 21. Reverse transcription polymerase chain reaction was performed to evaluate the relative amounts of GCA-R, GCB-R and clearance-R mRNA expression. The mRNA expression of GCA-R, GCB-R, and clearance-R was significantly increased in CDH compared to control lung. ANP receptor mRNA expression was significantly decreased in CDH lung with compared to without Dex treatment. Our finding of increased ANP receptor mRNA expression in CDH lung suggests that the hypoplastic lung has high sensitivity for ANP. Decreased mRNA expression of ANP receptors in CDH lung after Dex treatment suggests that AGT may improve pulmonary physiological function of ANP in hypoplastic CDH lung.

Animals↗
PubMedDate not supplied

Evaluation of diaphragmatic movement with MR fluoroscopy in chronic obstructive pulmonary disease.

The aim of this study was to show reduction of the diaphragmatic excursion with MR fluoroscopy in patients with chronic obstructive pulmonary disease (COPD) and to compare the results with pulmonary function test (PFT). The study included 13 men and 10 women (average age 56.2) with COPD, and 9 men and 6 women (average age 55.8) as a control group. MR fluoroscopy images with Spoiled Gradient-echo pulse sequence was obtained during deep inspiration and expiration. After examination, over cine-loop display, the highest and lowest positions of the diaphragm were identified and the distance of excursion was measured. Differences in the diaphragmatic excursion between patient and healthy subjects were compared. We have also compared MR fluoroscopy results with PFT. In each person of both groups, excursion of the diaphragm was demonstrated clearly in cine-loop display. Differences of excursion between deepest and highest point of diaphragm were on average 26 and 20 mm, respectively, in the right and left side in patients and 69 and 56 mm in healthy group. Significant correlation was found between expiratory volume in 1 s and MR fluoroscopy results. MR fluoroscopy study showed that there were significant statistical differences in diaphragmatic excursion between patients with COPD and healthy subjects. Expiratory volume in 1 s is closely associated with the diaphragmatic excursion. MR fluoroscopy would seem to be a useful method for showing diaphragmatic excursion.

Adult↗
PubMed1981

A method for quantitation of hepatic, pancreatic, and intestinal function in conscious Yucatan miniature swine.

A right laparotomy was performed in anesthetized miniature swine. A hepatic vein was catheterized through the diaphragmatic surface of the left lateral lobe of the liver or through the cut surface of the right lateral lobe following a partial lobectomy. Continuous wave Doppler flow cuffs were applied to the hepatic artery and portal vein. Portal vein catheterization was accomplished through a stab incision made through the center of a preplaced purse string suture. Catheters and flow cuff wires exited the abdomen at the dorsal limit of the incision and were placed in nylon packs. Sterile surgery of the right ventro-lateral cervical region allowed catheterization of the right external jugular vein and carotid artery. These catheters were passed subcutaneously to the dorsum of the neck and inserted into another nylon pack. This method allowed repetitive experiments on conscious miniature swine after recovery from surgery. It allowed accurate quantitative determination of hepatic extraction of hormones as well as extraction of production of metabolites. Rates of intestinal absorption and pancreatic hormone secretion also could be assessed.

Animals↗
PubMed1996

Congenital diaphragmatic hernia: can prenatal ultrasonography predict outcome?

OBJECTIVE: We wanted to establish whether prenatal ultrasonography predicts postnatal outcome in congenital diaphragmatic hernia. STUDY DESIGN: We designed a retrospective multicenter cohort study of 135 patients with congenital diaphragmatic hernia (122 left, 10 right, 2 bilateral, 1 anterior). In isolated left congenital diaphragmatic hernia five potential prenatal prognostic factors were studied: diagnosis at < or = 25 weeks' gestation, polyhydramnios, intrathoracic stomach, small abdomen, and major mediastinal shift. RESULTS: None of the 44 fetuses or infants who had multiple malformations survived. Of the 91 cases of isolated congenital diaphragmatic hernia, there were 82 live births; 76 of these infants had a left congenital diaphragmatic hernia. Of these, 51 (67%) died postnatally. A statistically significant relation was found between mortality and polyhydramnios, intrathoracic stomach, and major mediastinal shift. Mortality increased as a function of the number of these prognostic factors from 20% when none was present to 94% when all three were present. CONCLUSION: In the majority of cases of isolated left congenital diaphragmatic hernia the prognostic value of fetal ultrasonography is too low to alter perinatal management.

Cohort Studies↗
PubMed1987

[Clinical and functional course of a group of patients with COPD under controlled medical-rehabilitative treatment over a 6-year period].

Functional and clinical tests were performed on a group of 36 patients with COPD for 6 years. During this period they had medical treatment as well as cycles of respiratory rehabilitation (diaphragmatic breathing and exercise training). After this period the resistance to muscular work was greatly enhanced in 9 subjects (25%), enhanced in 25 (69%), little enhanced in 2. Functional respiratory parameters did not change in a significant way, thus indicating the stability of the disease, which did not worsen. One interesting feature was the mean reduction in residual volume (-32%, p less than 0.001). This may indicate that a better coordination of the diaphragm can reduce pulmonary hyperinflation. The ventilatory pattern spontaneously changed towards a stability of ventilation, with increased respiratory frequency and reduced tidal volume.

Breathing Exercises↗
PubMed1996

Chest wall and spinal deformities in adults with congenital diaphragmatic defects.

Between 1948 and 1980, 107 of 164 patients survived after repair of congenital diaphragmatic defects. To study chest wall and spinal deformities among these patients, 60 survivors (mean age, 29.6 +/- 9.0 years) underwent clinical examination, chest and spinal radiography, spirometry, and diffusing capacity measurements. Twenty-seven of these patients also had body pletysmography, xenon 133 radiospirometry, and a test for bronchial hyperreactivity. Chest asymmetry was present in 29 patients (48%). Eleven patients (18%) had pectus excavatum, and one had a pectus carinatum deformity. Anterior asymmetry, pectus deformities, and a flat chest were more common among the patients who initially had a large diaphragmatic defect. Two patients underwent anterior thoracoplasty because of their deformities. Sixteen patients (27%) had significant scoliosis (Cobb angle > or = 10 degrees). Scoliosis was more common in patients with ventilatory impairment than in those with normal lung function. One patient required spinal stabilization, one with severe kyphoscoliosis remains under observation, and a patient with moderate scoliosis was treated with a spinal brace. The results of this study indicate that chest wall deformities and scoliosis are common among adults with repaired congenital diaphragmatic defects. In most patients the deformity is mild, but some will require surgery. Surveillance until adulthood is appropriate.

Adolescent↗
PubMed1994

Nicardipine enhances diaphragmatic fatigue.

The effects of nicardipine, a calcium channel blocker, on diaphragmatic fatigue were studied in 20 anaesthetized, mechanically ventilated dogs divided into two groups: control group (Group C, n = 10) and nicardipine group (Group N, n = 10). Diaphragmatic fatigue was induced by intermittent supramaximal electric stimulation to bilateral phrenic nerves at a frequency of 20 Hz for 30 min. In Group N, 5 micrograms.kg-1.min-1 nicardipine iv was infused continuously during this fatigue-producing period. Transdiaphragmatic pressure (Pdi) produced by electrical stimulation (10-100 Hz) of the phrenic nerves was used as an index of diaphragmatic contractility. After a fatigue-producing period, the Pdi in both groups decreased at low frequency (10-30 Hz) stimulation compared with pre-fatigue values (P < 0.05), whereas no change in Pdi was observed at high-frequency (50-100 Hz) stimulation. The decrease of Pdi at low-frequency stimulation was larger in Group N (P < 0.05). The integrated diaphragmatic electric activity (Edi) in both groups did not change at any frequency of stimulation throughout the experiment. We conclude that nicardipine enhances diaphragmatic fatigue.

Animals↗
PubMed1998

Multiplanar and three-dimensional reconstruction techniques in CT: impact on chest diseases.

The purpose of this review is to capture the current state-of-the art of the technical aspects of multiplanar and three-dimensional (3D) images and their thoracic applications. Planimetric and volumetric analysis resulting from volumetric data acquisitions obviates the limitations of segmented transverse images. Among the 3D reconstruction techniques currently available, the most recently introduced technique, i. e., volume rendering, has to be evaluated in comparison with 3D shaded surface display and maximum or minimum intensity projection. Slabs are useful in detecting and localizing micronodular or microtubular patterns and in analyzing mild forms of uneven attenuation of the lungs. Three-dimensional angiography is helpful in the pretherapeutic evaluation and posttreatment follow-up of pulmonary arteriovenous malformations, in the comprehension of the postoperative reorientation of the pulmonary vessels, in the surgical planning of pulmonary tumors, and in the diagnosis of marginated thrombi. The systemic supply to the lung and superior vena cava syndromes are also relevant to these techniques. In acquired or congenital tracheobronchial diseases including stenosis, extraluminal air and complex airway anatomy, multiplanar and 3D reformations have a complementary role to both transaxial images and endoscopy. New developments are also expected in various topics such as 3D conformal radiation therapy, planning of intraluminal bronchoscopic therapy, virtual endoscopy, and functional imaging of the bronchial tree. Miscellaneous clinical applications are promising in the analysis of diaphragmatic morphology and pathophysiology, in the volumetric quantification of the lung parenchyma, and in the vascular components of the thoracic outlet syndromes.

Angiography↗
PubMed1995

Hypoxemia does not affect the strength of the inspiration-inhibiting Breuer-Hering reflex.

Several studies were focused on the consequences of reduced PaO2 (hypoxemia) on the Breuer-Hering inspiration-inhibiting vagal reflex. However, these data are often contradictory and do not allow us to decide whether hypoxemia interacts with the central integration of pulmonary vagal afferents and/or exerts peripheral influence on pulmonary stretch receptor (PSR) activity. The present study was performed in anesthetized rabbits breathing different gas mixtures containing O2, N2 and CO2. Intravenous injection of bicarbonates and CO2 addition in the inspired mixture maintained pHa and PaCO2 within their physiological ranges. The Breuer-Hering reflex, assessed from the changes in diaphragmatic EMG activity, was elicited either by inflating the lungs at different volumes above the functional residual capacity (PSR activation) or by direct electrical stimulation of vagal afferents (central stimulation). Hypoxemia never significantly modified the strength of the reflex or its threshold. Thus, acute hypoxemia present at high altitude does not seem to modify the key role played by PSR afferents in the ventilatory control.

Animals↗
PubMed2000

Functional anatomy of the gastroesophageal junction.

The study of the functional anatomy of the gastroesophageal junction allows for the demonstration of a double mechanism that combats the conflict of pressures that tends to lead to gastroesophageal reflux. On one hand, the LES, an intrinsic structure, is directly related to the muscle fibers of the organ and responds to a neurohormonal physiologic command. On the other hand is an anatomic entity, centered by the crura of the diaphragm, closely related to the movements of respiration. These structures constitute a second, extrinsic sphincter that gives rise to the zone of high pressure in the terminal esophagus. This role is difficult to assess, and its importance is underestimated. The proper functioning of these two mechanisms implies that the gastroesophageal junction remains in place within the diaphragmatic channel of the esophagus. Also important are the postural phenomena associated with the sloping position of the fundus. In patients with gastroesophageal reflux, the decrease of the pressure measured in the terminal esophagus accounts for the occurrence of reflux. Investigators concede that, under the influence of abdominal straining, the gastroesophageal junction tends to ascend into the diaphragmatic channel. The results are twofold: (1) the muscle fibers of the lower esophagus relax, explaining the incompetence of the intrinsic sphincter, and (2) the sphincteric zone is withdrawn from its muscular diaphragmatic environment. Physicians should consider these structures as a whole in approaching the surgical treatment of reflux. The construction of a periesophageal valve has no anatomophysiologic basis. A gastropexy procedure must be added to replace the gastroesophageal junction in its anatomic setting and keep it there. This procedure also allows retightening of the muscle fibers of the esophageal wall, which is essential in long-term surgical correction.

Esophagogastric Junction↗
PubMed1994

Exercise for arthritis.

The data available indicate that ROM, strengthening and aerobic conditioning exercises are safe for patients with OA, RA or AS, despite earlier concerns that exercise might exacerbate joint symptoms or accelerate disease. Less clear are the therapeutic benefits of exercise. In patients with OA, stretching, strengthening, and aerobic conditioning programmes can improve the deficits observed in these patients. The improvements observed generally have been small, and the evidence that these individual improvements result in improved overall function is minimal. None the less, it is likely that exercise will reduce pain, improve endurance for physical activities and improve cardiovascular fitness. Study of the long-term effects of exercise in the geriatric population, for sustaining independent living and functioning, is critically important for future health care and social expenditures. In RA, strengthening and aerobic conditioning exercise programmes can increase muscle strength and cardiovascular fitness and probably improve physical function as well. Improvements demonstrated in patients with RA seem more convincing than those in patients with OA and AS; this probably represents their poorer physical status prior to exercising. For patients with AS, intensive physiotherapy brings statistically significant short-term improvements in spinal and hip ROM which are only modestly clinically significant. It is possible that spinal mobility exercises decelerate loss of mobility over the long term, but controlled studies are needed to confirm this. Improvement in respiratory function with exercise appears to be related to cardiopulmonary fitness and perhaps to improvements in diaphragmatic respiration rather than to changes in thoracic cage mobility. Given the overall safety and likely benefits of the described forms of exercise, exercise should be included in the overall treatment of patients with OA, RA or AS. Careful patient evaluation and education about exercise should be a part of the exercise programme.

Arthritis↗
PubMed2001

[Fascia lata transplant from cadaveric donor in the reconstruction of abdominal wall defects in children].

INTRODUCTION: Abdominal wall closure is not possible in large congenital defects, even after extensively stretching in to enlarge its capacity. The skin coverage is usually adequate but the aponeurotic defect has to be closed temporally using synthetic patches. The use of these materials leads to increase complication such as infection, fistula formation and extrusion. In addition a second operation is required to remove the material and to perform a definitive closure. The role of fascia lata in reconstruction of abdominal wall is well established as free grafts, pedicled flaps or free flaps. Bank cadaveric fascia lata is used extensively in neurosurgical, ophtalmological, orthopaedic and urogynecological procedures. This is the first description of the use of cadaveric fascia lata for the closure of large abdominal wall defects. CASE REPORTS: We present two cases of congenital diaphragmatic hernia. The first patient was a newborn who presented the impossibility to close the fascia, that was salvaged by a teflón patch. Five months later the wound opened, leaving the mesh exposed that had to be removed. A cadaveric fascia lata patch was used to cover the defect, closing the skin satisfactorily. The second case was a two days newborn. We performed the diaphragmatic closure, and the aponeurotic defect was closed using cadaveric fascia lata. RESULTS: Cosmetic and functional appearance are satisfactory in both cases and no complications have been seen. CONCLUSION: Fascia lata patches are revascularized in the abdominal wall and incorporates into receptor tissue. They have the following advantages with respect to synthetic materials: First, the risk of complications is lower. Second, their removal is not necessary. Finally, no intraperitoneal adhesions occur. The risks of disease transmission and rejection are minimized by the Centro Comunitario de Transfusiones donor selection and processing of the cadaveric fascia lata.

Abdominal Muscles↗
PubMed2000

Adrenocortical insufficiency in infants with congenital diaphragmatic hernia: a pilot study.

BACKGROUND/PURPOSE: Prior reports have documented that premature infants do not have normal serum levels of cortisol. In contrast, full-term infants usually have adequate cortisol levels. The stress response in critically ill infants may be vital to their recovery. The purpose of this pilot study was to determine whether critically ill full-term infants with congenital diaphragmatic hernia (CDH) show a subnormal adrenal stress response. METHODS: Random serum cortisol levels in infants with CDH (n = 10) were measured using fluorescent polarization immunoassay. In addition, serum cortisol levels were measured after exogenous adrenocorticotropic hormone stimulation (Cosyntropin stimulation test). RESULTS: Six of the 10 infants studied died. Most (79%) of the cortisol levels were subnormal (<7 microgm/dL). Although no significant differences in mean cortisol levels from terminally ill infants compared with surviving infants were detected, survivors tended to have higher cortisol levels. Cosyntropin stimulation resulted in inappropriately low cortisol levels in 2 of the 4 fatally ill patients tested (<30 microgm/dL) and normal responses in the 2 survivors tested. CONCLUSIONS: Infants born with CDH may have an inadequate adrenal stress response despite a life-threatening anomaly. A large-scale prospective study may be warranted to confirm this apparent association. Corticosteroid therapy may be beneficial in this population of patients.

Adrenal Cortex Function Tests↗