PubMed Health⌕ Search

SEARCH · PubMed Health

Results for “Diaphragmatic function”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 973 records · Page 54Linked to original sources
PubMedDate not supplied

Entrapment of the colon following diaphragmatic injuries: report of eight cases.

With a rise in the incidence of severe injuries, we are seeing increasing numbers of patients with colonic entrapment occurring at the sites of diaphragmatic injuries. The initial injury might have occurred recently or it might have occurred as long as 25 years before. Blunt trauma, stabbings, and infection accounted for the initial trauma in our patients. Acute symptoms implicate the cardiorespiratory system as a result of interference with respiration and the filling and function of the heart. Acute or chronic gastrointestinal symptoms may suggest intestinal obstruction or functional bowel disorders. The proper diagnosis of colonic entrapment depends upon a high index of suspicion and proper studies. Chest x-rays, fluoroscopy, barium-enema examinations and contrast studies of the upper gastrointestinal tract are essential. Acute cardiorespiratory enbarrassment necessitates prompt surgical intervention. When subdiaphragmatic injuries are suspected, an abdominal incision is necessary. In long-standing cases where the abdominal viscera are intact, the thoracic approach is preferable. At times, the combined thoraco-abdominal incision may be preferable. Diaphragmatic injuries resulting in colonic entrapment occurred most often in the left hemidiaphragm, which is relatively unprotected. In seven of our eight patients, the left diaphragm was the site of herniation. The liver on the right side serves to protect this area from herniation. Only the largest defects permit displacement of the liver into the right chest. Only one of our patients had such a defect. Patients with long-standing cardiac or gastrointestinal symptoms suggestive of colonic entrapment should have a THOROUGH MEDICAL evaluation before any operative treatment is advised. We have reviewed the cases of eight patients in whom infection, stabbings and blunt trauma resulted in diaphragmatic herniations with subsequent colonic entrapment. The splenic flexure of the colon protruded through the defect in three of our eight patients. The transverse colon was located above the diaphragm in five.

Adult↗
PubMed1991

Reverse-perfused sleeve: an improved device for measurement of sphincteric function of the crural diaphragm.

The sphincteric function of the crural diaphragm has been difficult to measure in humans. The authors recently reported the use of a Dent sleeve device to measure esophagogastric junction pressure during contraction of the crural diaphragm. However, the major limitation of the conventional sleeve device is its slow response rate, and sustained diaphragmatic contractions of 6-8 seconds must be induced to measure the true pressure. In this article, the principles of a reverse-perfused sleeve device and the theoretical basis for its fast response rate are reported. The reverse-perfused sleeve is validated in an in vitro model of the lower esophageal sphincter. Furthermore, in vivo studies were performed in seven healthy human subjects. Standardized Muller maneuvers and straight-leg raises were performed to induce diaphragmatic contractions. Pressure increases of 50-150 mm Hg during diaphragmatic contractions were attained in less than 1 second. The delay between the actual contraction of the diaphragm as measured by simultaneously recorded crural diaphragm electromyography and pressure recorded by the sleeve was only 0.25-0.50 seconds. Increasing the rate of infusion of the sleeve from 0.5 to 1.0 mL/min did not further improve the response rate of the reverse perfused sleeve. It was concluded that the reverse-perfused sleeve is a considerable improvement over the conventional sleeve for quantitating the sphincteric function of the crural diaphragm. The role of the crural diaphragm in reflux esophagitis may be easily investigated using a reverse-perfused sleeve device.

Diaphragm↗
PubMed1977

Posterolateral diaphragmatic hernia--long-term results.

During the years 1965--1974, 125 cases of posterolateral diaphragmatic hernia have been operated at five departments of pediatric surgery in Sweden. The overall operative mortality was 50%. A follow-up investigation included 19 cases, where in 12 cases spirometry and in 11 cases studies of the mobility of the diaphragm were included. Physical examination revealed excellent results in most cases. Lung function studies, however, show a moderate (20--30%) reduction, which is not surprising with regard to lung hypoplasia and impaired movement of the diaphragm on the operated side. In adolescence and younger age, these patients are mostly in excellent condition; but later, when lung function is also reduced by the age factor, their neonatal condition may be of importance.

Adolescent↗
PubMed1997

Diaphragmatic fatigue investigated by phonomyography.

Diaphragmatic phonomyogram (PMG) evoked by maximal bilateral phrenic nerve stimulation has previously been described as a good index of contractility of fresh and fatigued diaphragm. In the present study we hypothesized that diaphragmatic contractility changes could be even more simply evaluated by recording the relationship between the PMG and the compound motor action potential (CMAP) amplitudes during graded submaximal unilateral phrenic nerve stimulation at various intensities. Relationships between CMAPs and PMGs from left and right hemidiaphragms were recorded by means of surface electrodes and miniature microphones placed over the lower rib cage (eighth intercostal space) in five healthy subjects before and after a diaphragmatic fatigue task. These relationships in each subject were linear. The slope of these relationships decreased by 61.1 +/- 20.7% and by 70.4 +/- 14.6% on the right and left side respectively, but the intercepts did not change significantly. By comparison, transdiaphragmatic twitch pressure during maximal bilateral stimulation (PdiT) declined by 49.4 +/- 15%. We conclude that PMG during submaximal unilateral phrenic nerve stimulation is a reliable index of diaphragm contractility changes caused by fatigue. Using this method we have shown that all diaphragmatic motor units can be affected by fatigue.

Action Potentials↗
PubMed1976

[Morphological and functional changes in the closing sphincter of the lower esophagus after experimentally-induced hiatal hernia].

Report of an experimental model of axial hiatal hernia in dogs, always combined with reflux (roentgenologic control). Using a new method of pressure measurement, the authors succeeded in proving the distention of the esophageal "sphincter". Morphologic investigations demonstrated, that in hernia the muscle fiber is no longer an apolar helical fiber, but runs nearly horizontally. The reduced susceptibility to pentagastrin is caused by diminished tension of the muscle fiber. The distal esophageal closing mechanism consequently seems to be a function of the whole organ and not of a hormonally regulated sphincter.

Animals↗
PubMed1999

Diaphragmatic paresis as a manifestation of large artery vasculitis.

We describe the initial presentation and followup of a 54-year-old Caucasian woman who presented in 1995 with bilateral arteritis of the axillary arteries and acute onset dyspnea. Chest radiograph, chest fluoroscopy, and pulmonary function studies confirmed the diagnosis of right hemidiaphragmatic paresis. Prednisolone and methotrexate therapy and short term anticoagulation were initiated and she experienced no further sequelae during 2 years of followup.

Anti-Inflammatory Agents↗
PubMedDate not supplied

Bilateral cervical posterior rhizotomy: effects on dystonia and athetosis, on respiration and other autonomic functions.

Bilateral cervical posterior rhizotomy of C1 through C4, C5 or C6 was performed in 16 patients affected by dystonia and athetosis resulting from infantile cerebral palsy. The majority showed decreased muscle spasms and athetoid movements, with some improvements in their posture and voluntary mobility. 5 patients suffered from uneven and irregular breathing associated with lethargy immediately postoperatively, and 4 also showed reduced diaphragmatic activity; all 4 of these patients developed pneumonia, transitory in 3, but fatal to the other. Urinary retention lasting for a maximum of 3 months occurred in 4 of the 5 patients. The authors suggest that the lesion of ascending reticular fibers in the cervical posterior roots could have been responsible for the observations.

Adolescent↗
PubMed2001

Prognostic indicators of survival in infants with congenital diaphragmatic hernia.

PURPOSE: This study sought to identify the factors predictive of the short-term outcome in infants with congenital diaphragmatic hernia (CDH). METHODS: We retrospectively reviewed medical records from September 1985 to December 1998 for all infants born with CDH and managed at National Taiwan University Hospital (NTUH). Coexisting pathology and measures of respiratory function were analyzed to determine the prognostic factors. RESULTS: A total of 32 infants with CDH were managed at NTUH over the past 13 years. The investigated factors associated with poor prognosis in CDH included congenital heart disease, chromosomal abnormality, pneumothorax, and preoperative parameters including arterial partial carbon dioxide pressure greater than 40 mmHg, arterial partial oxygen pressure less than 100 mmHg, alveolo-arterial partial oxygen pressure greater than 610 mmHg, and oxygen index (OI) greater than 0.4. Multiple logistic regression analyses indicated that only an OI greater than 0.4 and pneumothorax were significant indicators of poor prognosis. When the incidence of pneumothorax was compared between patients who received ventilation using a conventional mechanical ventilator or high-frequency oscillatory ventilator (HFOV), a trend toward a lower incidence of pneumothorax in those using HFOV for initial stabilization was found (p = 0.08). CONCLUSIONS: An OI greater than 0.4 before surgery and pneumothorax are poor prognostic indicators in infants with CDH. A high OI is reflective of the severity of pulmonary dysfunction in infants. Pneumothorax further compromises the dysfunction of a hypoplastic lung in infants with CDH. The results of this study show the importance of avoiding iatrogenic pneumothorax during management of infants with CDH.

Female↗
PubMed2004

Dyspnea as the predominant manifestation of bilateral phrenic neuropathy.

Phrenic neuropathy associated with brachial neuritis has been well described; however, bilateral phrenic neuropathy with minimal or no involvement of the brachial plexus has not. We review the clinical features, as well as the results of radiographic studies, pulmonary function tests, and electrodiagnostic studies, of 3 patients in whom dyspnea was the presenting manifestation of bilateral phrenic neuropathy. All 3 patients had acute-onset dyspnea, which led to consideration of a pulmonary or cardiac etiology. Phrenic nerve conduction studies showed bilateral axonal degeneration of the phrenic nerves. Diaphragmatic paralysis should be considered in the differential diagnosis of acute-onset dyspnea. Dyspnea increases typically when the patient lies down, and paradoxical respiration may be present. Neck, shoulder, or upper limb pain may occur at onset. Inspiratory pressures may be reduced, but a comparison of the forced vital capacity when the patient is standing and supine is more specific for diaphragmatic weakness. Phrenic nerve conduction studies and diaphragmatic electromyography may provide evidence of bilateral involvement. Subclinical evidence of brachial plexus involvement may be present. The prognosis for patients with bilateral phrenic neuropathy may be more favorable than reported previously.

Brachial Plexus Neuritis↗
PubMed1992

Pathophysiology of congenital diaphragmatic hernia II: the fetal lamb CDH model is surfactant deficient.

The high mortality for congenital diaphragmatic hernia (CDH) has been attributed to a combination of pulmonary hypoplasia and pulmonary hypertension. We hypothesize that a surfactant deficiency may in part be contributing to the pathophysiology of CDH. This study documents the functional, quantitative, and qualitative aspects of the surfactant status of the alveolar air-liquid interface and the type II pneumocyte in the fetal lamb CDH model. Ten lamb fetuses (gestational age, 80 days) had a CDH created via a left thoracotomy and then were allowed to continue in utero development until term. Three litter mates and three nonoperated time-dated fetuses served as controls. At term, pressure-volume curves were performed to measure pulmonary compliance and total lung capacity. Alveolar lavage was then performed to measure the quantitative and the qualitative aspects of pulmonary surfactant. Finally, isolation of type II pneumocytes allowed quantification of phospholipid synthesis. When compared with controls (N = 6), the CDH lambs (N = 5) had significantly smaller lungs (P = .009), decreased total lung capacity (P less than .001) and compliance (P less than .001), reduced total lavaged phospholipids (P = .006), and decreased percent phosphatidylcholine (P = .02). CDH lambs also had increased total lavaged proteins (P = .05) and higher minimum dynamic surface tension (P less than .001). A surfactant deficiency may be contributing to the pathophysiology of CDH. Surfactant replacement therapy in premature infants has been shown to improve lung compliance, decrease morbidity, and improve survival. Exogenous surfactant may also benefit infants with CDH.

Animals↗
PubMed1983

[Experimental intrauterine surgery. Morphological study of lung development in the sheep fetus with congenital diaphragmatic hernia].

Experimental comparison of the lungs of 7 sheep foetuses with surgically induced CDH and 7 controls permitted an assessment to be made of the changes that take place in lung growth, generally described as hypoplasia, through a study of their morphology and histology, and the lung: lamb weight ratio. Changes increased in gravity in function of the duration of hernia. They included: reduced alveolar expansion, fewer generations of bronchi and alveoli, and septal thickening. An increase in the smooth muscle component of 5th-6th generation arteries (i.e. resistance) may offer an explanation of the hypertension characteristic of CDH, and the non-reactivity of these vessels in response to vasodilators. It is also suggested that damage to the mesenchyma can be regarded as the sole cause of the changes in lung growth observed in CDH. Early treatment before these changes become irreversible is thus advisable.

Animals↗
PubMed2003

Bilateral phrenic-nerve paralysis treated by thoracoscopic diaphragmatic plication in a neonate.

Traditionally, diaphragmatic plication (DP) is performed via a thoracotomy that includes incision of the lower intercostal muscles, which are involved in respiratory movement. This may adversely affect ventilation by causing deterioration of respiratory function and making ventilation less efficient. These problems do not occur with thoracoscopic DP (TDP), since the lower intercostal muscles are left intact. We describe a full-term newborn infant with bilateral phrenic-nerve paralysis (PNP) who was treated by TDP and conclude that this method may be effective in the treatment of PNP even in small infants.

Diaphragm↗
PubMed1982

Influence of upper airway pressure changes on respiratory frequency.

Influences of pressure changes within the upper airway on respiratory frequency were studied in anesthetized rabbits. These reflex effects were investigated in two ways: (1) by applying sustained negative or positive pressures to isolated upper airway in vagally intact animals during tracheostomy breathing, and (2) by briefly occluding the nasal airways of vagotomized animals at end expiration. Negative pressure applied to isolated upper airway decreased the respiratory frequency (P less than 0.01). Decrease in respiratory frequency correlated with magnitude of pressure change. In contrast, positive pressures produced an increase in respiratory frequency (P less than 0.05). But, the increase in frequency correlated poorly with magnitude of positive pressure change. A post-stimulus effect lasting several breaths was seen following the release of both negative and positive pressures (P less than 0.01). Nasal occlusion in vagotomized animals was associated with an increase in Ti and Ttot of the first nasally occluded breath (P less than 0.05). Increase in Ti was not associated with an increase in peak diaphragmatic activity. This would result in decreased inspiratory load on the upper airway patency maintaining muscles by reducing the mean inspiratory pressure. Hence, these reflex responses to airway pressure could play a functional role in the maintenance of upper airway patency.

Animals↗