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PubMed2006

Diaphragmatic weakness after transcatheter arterial chemoembolization of inferior phrenic artery for treatment of hepatocellular carcinoma.

PURPOSE: To prospectively assess the diaphragmatic anatomic and functional consequences of transcatheter arterial chemoembolization (TACE) of the inferior phrenic artery in patients with hepatocellular carcinoma. MATERIALS AND METHODS: Informed consent and institutional review board approval were obtained. Fifteen patients (13 men, two women; mean age, 52 years; age range, 22-61 years) who underwent TACE of the inferior phrenic artery for treatment of hepatocellular carcinoma were enrolled. The right inferior phrenic artery was embolized in 14 patients, and the left inferior phrenic artery was embolized in one patient. Chest radiography, fluoroscopy, computed tomography (CT), and pulmonary function tests were performed before and after TACE of the inferior phrenic artery. The post-TACE examinations were performed 2-3 months after TACE, and the results were compared with those of the pre-TACE examinations. A paired t test or the Wilcoxon signed rank test was used for statistical analyses. RESULTS: At chest radiography and fluoroscopy, six of 15 patients (40%) had both elevation and movement abnormality of the ipsilateral hemidiaphragm after TACE of the inferior phrenic artery. The mean (+/- standard deviation) diaphragmatic thickness on CT scans changed from 9.11 mm +/- 3.02 to 7.67 mm +/- 2.27 after TACE (P = .048). The mean vital capacity also was significantly decreased after TACE, from 91.87% +/- 18.52 to 82.27% +/- 16.94 of the predicted value (P = .006). The decreases in diaphragmatic thickness and vital capacity were most pronounced in the patients with abnormal findings at chest radiography and fluoroscopy. CONCLUSION: After TACE of the inferior phrenic artery, a substantial portion of patients showed functional and anatomic evidence of diaphragmatic weakness.

Adult↗
PubMed1985

[Quantitative determination of diaphragmatic motility using ultrasound. Comparison with pulmonary function test parameters and thoracic radiography].

Sonography, combined with a geometrical simulation-model, can be used to estimate parameters of pulmonary function tests (PFT). The sensitivity for changes of PFT may be increased by repetitive examinations. This simple inexpensive method is easily reproducible. Additional information concerning diaphragmatic motility is obtained. The value of this method is improved by taking geometric parameters directly from chest radiograph using a suitable computer program.

Adolescent↗
PubMed2006

Impaired mesenchymal cell function in Gata4 mutant mice leads to diaphragmatic hernias and primary lung defects.

Congenital diaphragmatic hernia (CDH) is an often fatal birth defect that is commonly associated with pulmonary hypoplasia and cardiac malformations. Some investigators hypothesize that this constellation of defects results from genetic or environmental triggers that disrupt mesenchymal cell function in not only the primordial diaphragm but also the thoracic organs. The alternative hypothesis is that the displacement of the abdominal viscera in the chest secondarily perturbs the development of the heart and lungs. Recently, loss-of-function mutations in the gene encoding FOG-2, a transcriptional co-regulator, have been linked to CDH and pulmonary hypoplasia in humans and mice. Here we show that mutagenesis of the gene for GATA-4, a transcription factor known to functionally interact with FOG-2, predisposes inbred mice to a similar set of birth defects. Analysis of wild-type mouse embryos demonstrated co-expression of Gata4 and Fog2 in mesenchymal cells of the developing diaphragm, lungs, and heart. A significant fraction of C57Bl/6 mice heterozygous for a Gata4 deletion mutation died within 1 day of birth. Developmental defects in the heterozygotes included midline diaphragmatic hernias, dilated distal airways, and cardiac malformations. Heterozygotes had any combination of these defects or none. In chimeric mice, Gata4(-/-) cells retained the capacity to contribute to cells in the diaphragmatic central tendon and lung mesenchyme, indicating that GATA-4 is not required for differentiation of these lineages. We conclude that GATA-4, like its co-regulator FOG-2, is required for proper mesenchymal cell function in the developing diaphragm, lungs, and heart.

Animals↗
PubMed1991

Pulmonary function in newborns after repair of congenital diaphragmatic hernia.

Congenital diaphragmatic hernia (CDH) is associated with pulmonary hypoplasia that limits survival, but the nature and extent of pulmonary dysfunction in neonates with CDH have not been studied. We performed pulmonary function tests (PFTs) in eight intubated infants who survived neonatal repair of CDH (wt, 3.33 +/- 0.15 kg; age, 20.1 +/- 2.7 d; mean +/- S.E.M.). PFTs obtained from six full-term infants (wt, 3.56 +/- 0.15 kg; age, 25.0 +/- 3.3 d) with no respiratory illness served as controls. The deflation flow-volume curve technique produced maximum expiratory flow-volume (MEFV) curves, giving reproducible measurements of forced vital capacity (FVC) and maximal expiratory flow at 25% of FVC (MEF25). Respiratory system compliance (Crs) and resistance (Rrs) were obtained with a modified passive mechanics technique. In seven of eight infants PFTs were repeated after nebulized bronchodilator (0.1% isoetharine). In neonates surviving CDH repair, as compared to those with normal lung function, FVC was significantly reduced (20.78 +/- 3.32 vs. 39.83 +/- 3.30 mL.kg-1, P less than 0.05). MEF25 was also markedly reduced (20.78 +/- 3.32 vs. 39.83 +/- 3.30 mL.kg-1.s-1, P less than 0.05), indicating lower airway obstruction. After administration of nebulized bronchodilator, PFTs showed significant increases from control values in both FVC (15.9%) and MEF25 (200%) without changes in Crs and Rrs. These findings indicate that neonates with CDH have restrictive lung defects, reflecting hypoplasia. After surgical repair and mechanical ventilation airway reactivity develops, primarily in smaller airways, and this may complicate the postoperative course.

Forced Expiratory Flow Rates↗
PubMed1986

Diaphragmatic responses to body position changes in obese patients with obstructive sleep apnea.

Patients with severe obesity and obstructive sleep apnea (OSA) have been shown to have abnormalities in respiratory muscle function and respiratory control. The present study was done to evaluate diaphragmatic function and the diaphragm fiber-length-compensating reflex in morbidly obese patients with OSA (1). Twelve normal subjects and 13 morbidly obese patients with OSA were studied in recumbent and upright positions. In the normal subjects, the diaphragm fiber-length-compensating reflex operated normally causing the diaphragm's inspiratory EMG to increase when the diaphragm's fibers shortened with assumption of the upright position. However, 8 of the 13 obese patients with OSA showed a decrease rather than an increase in the inspiratory diaphragmatic EMG on assuming the upright posture. Further data indicate greater diaphragmatic efficiency in the upright than in the supine position in a majority of the obese patients, a reversal of the normal response. Two possible explanations of these observations are: an abnormality of central respiratory control in obese patients with OSA and overstretching of the diaphragm in the recumbent obese patient. The observation of reduced maximal transdiaphragmatic pressures in the recumbent position in some of the obese patients with OSA supports the second explanation. Diaphragmatic overstretching may be an important mechanism in the development of hypoventilation in the morbidly obese.

Adult↗
PubMed1994

[Diaphragmatic muscle fatigue--its diagnosis and treatment].

Transcutaneous stimulation electromyography of the diaphragm was performed in 64 patients suffering from chronic obstructive bronchitis (COB) to evaluate the function of the diaphragmatic muscle. Increased amplitude, area and shorter M-response gave evidence for the muscle fatigue. Changes in the above parameters correlated with the degree of the respiratory insufficiency and pulmonary hypertension. The authors included subcutaneous electrostimulation of the diaphragm in combined treatment of COB patients free of clinical manifestations indicating circulation decompensation. These patients benefited from the stimulation in contrast to COB patients with decompensated circulation who failed to respond to the procedure.

Adult↗
PubMed1983

Muscle fiber type distribution and architecture of the cat diaphragm.

Three types of diaphragmatic muscle fibers were identified histochemically in the sternal, costal, and crural regions of the cat diaphragm. Differences in the proportion of each muscle fiber type were observed between the abdominal and thoracic surfaces of the diaphragm but not among the different regions. A higher percentage of slow-twitch oxidative fibers was noted on the abdominal surface, whereas more fast-twitch fibers (fast-twitch oxidative-glycolytic and fast-twitch glycolytic) were found on the thoracic surface. Differences in muscle architecture were observed between diaphragmatic regions, but not between abdominal and thoracic sides. Overall, muscle fibers were longer in the crural regions, with the longest fibers being found in the crossing-band area of the crura. In the costal regions, fibers were longest in the center and became shorter toward the ventral and dorsal extent of these regions. Fiber lengths were similar throughout the sternal region. In each diaphragmatic region, the length of fibers extended from the origin of the muscle to its insertion. We conclude that functional differences between diaphragmatic regions could be attributed to fiber length and/or orientation, but not to differences in fiber-type composition.

Animals↗
PubMed1986

Diaphragmatic contractility after upper abdominal surgery.

Postoperative dysfunction of the diaphragm has been reported after upper abdominal surgery. This study was designed to determine whether an impairment in diaphragmatic contractility was involved in the genesis of the diaphragmatic dysfunction observed after upper abdominal surgery. Five patients undergoing upper abdominal surgery were studied. The following measurements were performed before and 4 h after surgery: vital capacity (VC), functional residual capacity (FRC), and forced expiratory volume in 1 s. Diaphragmatic function was also assessed using the ratio of changes in gastric pressure (delta Pga) over changes in transdiaphragmatic pressure (delta Pdi). Finally contractility of the diaphragm was determined by measuring the change in delta Pdi generated during bilateral electrical stimulation of the phrenic nerves (Pdi stim). Diaphragmatic dysfunction occurred in all the patients after upper abdominal surgery as assessed by a marked decrease in delta Pga/delta Pdi from 0.480 +/- 0.040 to -0.097 +/- 0.152 (P less than 0.01) 4 h after surgery compared with preoperative values. VC also markedly decreased after upper abdominal surgery from 3,900 +/- 630 to 2,060 +/- 520 ml (P less than 0.01) 4 h after surgery. In contrast, no change in FRC and Pdi stim was observed 4 h after surgery. In contrast, no change in FRC and Pdi stim was observed 4 h after upper abdominal surgery compared with the preoperative values. We conclude that contractility of the diaphragm is not altered after upper abdominal surgery, and diaphragmatic dysfunction is secondary to other mechanisms such as possible reflexes arising from the periphery (chest wall and/or peritoneum), which could inhibit the phrenic nerve output.

Abdomen↗
PubMed1998

Pulmonary function, exercise performance, and growth in survivors of congenital diaphragmatic hernia.

A cohort of survivors of congenital diaphragmatic hernia (CDH), with matched controls, was studied to assess growth, respiratory function, and exercise performance. Nineteen of 24 survivors from an 11 year period (79%) were compared with 19 matched controls. Subjects had detailed auxology, performed spirometry and cycle ergometry, and completed questionnaires about respiratory symptoms and exercise. There were no significant differences between the groups for height, weight, sitting height, head circumference, or body mass index expressed as SD scores. The mean (95% confidence interval) percentage predicted forced vital capacity (FVC) was 84.7% (79.1 to 90.3) in index cases and 96.5% (91.4 to 101.6) in controls (p < 0.01). There was no significant difference in total lung capacity. Expiratory flow rates corrected for FVC were also similar between groups, suggesting normal airway function relative to lung size. Mean maximum oxygen consumption in ml/kg/min was 40.1 (36.8 to 43.4) and 42.2 (38.5 to 45.8) in index and control cases. These differences were not significant. Index cases achieved a similar minute ventilation to controls by more rapid and shallower breathing. Index cases had lower perception of their own fitness and lower enjoyment of exercise, although habitual activity levels were similar. Survivors of CDH repair have reduced functional lung volumes, but normal airway function compared with matched controls. They have no growth impairment nor significant impairment of exercise performance, although they have more negative perceptions of their own fitness. They should be encouraged and expected to participate fully in sport and exercise.

Child↗
PubMed2003

[Diagnostic study on children's diaphragmatic fatigue].

OBJECTIVE: In the recent twenty years, the diaphragmatic contraction, relaxation functions and electric activity have been explored through electromyography (EMG) and transdiaphragmatic pressure (Pdi) determination. But these techniques required some complex and expensive instruments, so the diagnosis and treatment of children's diaphragmatic fatigue have not been well evaluated. The present study explored the diagnosis of children's diaphragmatic fatigue through measuring ribcage-abdomen motion and analyzed its asynchrony. METHODS: Fifty-three children (male 37, female 16, and age rage from 1 months to 9 years) with respiratory rate > 30 breaths/min, heart rate > 110 beats/min, and respiratory dysfunction had asynchronized ribcage-abdomen motion showed by impedance respirograph (IRG). The authors observed whether ribcage-abdomen motion was synchronic and calculated M levels (staggered peak time/total duration of the breathing cycle). The ribcage and abdomen outputs were displayed on vertical (for rib cage) and horizontal (for abdomen) axes of X-Y instrument. In addition, the change of respiratory frequency and heart rate was observed and arterial blood-gas analysis was also performed. RESULTS: (1) M levels in one-dimensional IRG were positively correlated with alpha angle in two-dimensional IRG (r = 0.956, P < 0.001). Asynchronized respiratory motions could be divided into three types. type I showed completely contra-directional movements of respiration, M levels for (48.1 +/- 4.4)%, an irregularly clockwise loop in the two dimensional IRG, and alpha angle for (138.3 +/- 15.0) degrees. In type II, one dimensional IRG showed displaced peak of the chest and abdomen motion curves, M levels were (16.5 +/- 4.7)%, two dimensional IRG was displaced in a counterclockwise direction, and alpha angle was (55.3 +/- 10.8) degrees. In type III, abdominal motion curve of one dimensional IRG had double peaks, M levels were 0, two dimensional IRG was presented as 8-shaped double circles, alpha angle was (41.3 +/- 3.8) degrees; (2) pH levels in the patients with type I and type II diaphragmatic fatigue were significantly lower, and PCO(2) levels were significantly higher than those with type III or in the normal subjects (P < 0.001 for all), but there was no statistically significant difference between type III and the normal subjects (P > 0.05); (3) Both of respiratory rate and heart rate in type I, type II and type III were higher than those in the normal subjects (all P < 0.001), and the differences among the three types were significant (P < 0.001 for all); (4) Both M levels and alpha angle were negatively correlated with pH levels (r = -0.514, P < 0.001 and r = -0.497, P < 0.001), while positively correlated with PCO(2) levels (r = 0.672, P < 0.001 and r = 0.625, P = 0.01). CONCLUSIONS: (1) IRG can be reliably used to diagnose children's diaphragmatic fatigue. This technique is simple and easy to perform and non-invasive. It is therefore worthy of recommending for further clinical investigations. (2) According to the characteristics of IRG, diaphragmatic fatigue can be divided into three types. (3) The development of children's diaphragmatic fatigue has a series of characteristic changes. (4) To avoid the patients suffering from respiratory failure, it is the key time to adopt the policies of prevention and treatment when IRG shows signs of type III diaphragmatic fatigue.

Child↗
PubMed2000

Children with congenital diaphragmatic hernia are at risk for lower levels of cognitive functioning and increased emotional and behavioral problems.

The physical, psychological, and social functioning of 11 children aged 8 to 12 years with Congenital Diaphragmatic Hernia (CDH) was assessed with several standardized assessment procedures. Physically, most children functioned well at follow-up with half of the children showing minor physical problems such as bronchial hyperreactivity. The mean IQ of the children was 15 points (1 SD) below the norm of 100. Only 6 children were at expected school level. The children showed more emotional and behavioral problems than in the general population as reported by parents and teachers. The children themselves reported more depressive problems, but not a lower self-esteem than children in the general population. These results were confirmed by the results of interviews with parents and children concerning psychosocial functioning. It is concluded that children with CDH show more cognitive and learning problems and increased rates of emotional and behavioral problems compared to children in the general population. Since no children treated with Extra Corporeal Membrane Oxygenation (ECMO) were involved in this study, the earlier reports that lower cognitive functioning is limited to children with CDH treated with ECMO can not be confirmed by this study. Considering the results of this study, there is a need for further follow-up studies concerning the long-term psychological and social functioning of children with CDH.

Child↗
PubMed2002

[Isolated, unilateral paresis of the phrenic nerve after pneumonia and pleurisy].

Unilateral diaphragmatic paralysis has many causes. Tumor and trauma are the two most frequent identifiable causes. Infectious processes involving the lung and/or mediastinum may result in temporary or permanent diaphragmatic paralysis. We report the case of an 81-year old man who suffered from right-sided pneumonia followed by a period of several months with exertion dyspnea. Radiological examinations showed an elevated right diaphragm, abnormal restrictive lung function, and impaired diaphragmatic muscle strength. The neurophysiological studies provided evidence of a partial phrenic nerve lesion. We discuss the differential diagnosis of isolated phrenic nerve lesions with particular regard to infections.

Aged↗
PubMed2006

Eventration of the diaphragm.

OBJECTIVE: Eventration of the diaphragm (ED) is defined as the abnormal elevation of the diaphragm. Although asymptomatic ED may be amenable to conservative treatment, symptomatic ED in children, either congenital or acquired, may require surgical treatment. This study evaluated the results of diaphragmatic plication in children with unilateral ED. METHODS: Fifteen patients who had undergone diaphragmatic plication for ED between 1997 and 2003 were evaluated retrospectively. The diagnosis of ED was established by routine chest radiographs and fluoroscopy. Patients who failed to respond to nonoperative treatment were referred for surgery. Nine patients underwent diaphragmatic fluoroscopy 1-5 years following plication to assess function. RESULTS: Indications for diaphragmatic plication were respiratory symptoms such as tachypnoea, dyspnoea, recurrent pneumonia and failure to thrive. In 14 patients, the position of the diaphragm was normal after plication, but the diaphragm was elevated without symptoms in one patient during postoperative follow-up. The motion of the diaphragm was investigated in nine patients. Fluoroscopic studies showed that the operated hemidiaphragm was immobile and there was no paradoxical motion. No return of symptoms was found during follow-up. CONCLUSION: ED is the abnormal elevation of the diaphragm as a result of paralysis or aplasia of the muscular fibres. The abnormally elevated diaphragm may compress the ipsilateral lung, and with respiratory effort the mediastinum may shift towards the normal side. Therefore, diaphragmatic plication is performed to restore normal pulmonary parenchymal volume by replacing the diaphragm in its normal location. After plication, there was immediate remission of symptoms in most patients and decreasing symptoms were observed for a year in others. During follow-up, the location of the diaphragm was normal and no paradoxical movement was observed. Relapse of symptoms was not noted in patients with immobile diaphragms.

Child, Preschool↗
PubMed2000

Unilateral diaphragmatic paralysis following bronchial artery embolization for hemoptysis.

Bronchial artery embolization is an effective treatment for patients with hemoptysis. Serious complications are rare, but may occur if the arterial supply to other structures is compromised. We present a case of unilateral diaphragmatic paralysis following bronchial artery embolization in a patient with cystic fibrosis. We believe that the diaphragmatic paralysis was due to the inadvertent obstruction of the left pericardiacophrenic artery during the embolization procedure, with compromise of the phrenic nerve blood supply. This resulted in a significant loss of lung function in our patient, who did not recover despite the subsequent return of diaphragmatic function.

Adult↗
PubMed2004

Demonstration of a second rapidly conducting cortico-diaphragmatic pathway in humans.

Functional imaging studies in normal humans have shown that the supplementary motor area (SMA) and the primary motor cortex (PMC) are coactivated during various breathing tasks. It is not known whether a direct pathway from the SMA to the diaphragm exists, and if so what properties it has. Using transcranial magnetic stimulation (TMS) a site at the vertex, representing the diaphragm primary motor cortex, has been identified. TMS mapping revealed a second area 3 cm anterior to the vertex overlying the SMA, which had a rapidly conducting pathway to the diaphragm (mean latency 16.7 +/- 2.4 ms). In comparison to the vertex, the anterior position was characterized by a higher diaphragm motor threshold, a greater proportional increase in motor-evoked potential (MEP) amplitude with voluntary facilitation and a shorter silent period. Stimulus-response curves did not differ significantly between the vertex and anterior positions. Using paired TMS, we also compared intracortical inhibition/facilitation (ICI/ICF) curves. In comparison to the vertex, the MEP elicited from the anterior position was not inhibited at short interstimulus intervals (1-5 ms) and was more facilitated at long interstimulus intervals (9-20 ms). The patterns of response were identical for the costal and crural diaphragms. We conclude that the two coil positions represent discrete areas that are likely to be the PMC and SMA, with the latter wielding a more excitatory effect on the diaphragm.

Adult↗
PubMed1990

Diaphragmatic fatigue after endotoxemic shock in rats: in vitro function and metabolism.

A rat model was used to study the effects of endotoxemic shock in vivo on diaphragmatic tension generation and diaphragmatic metabolism in vitro. Animals were injected with E. coli lipopolysaccharide (30 mg/kg) and killed at fixed times after injection. The hemidiaphragms were isolated in an organ bath, and tension generation was measured during electrical stimulation of the phrenic nerve or diaphragmatic muscle. Diaphragmatic oxygen consumption was measured in vitro during rest and during in vivo stimulation. Adenosine triphosphate and glycogen concentrations were measured in vivo before the animals were killed and in vitro. Tension generation was reduced in a time-dependent fashion after endotoxin at all stimulation frequencies. Both contractile fatigue and transmission fatigue were present. Glycogen stores were reduced but not depleted. ATP concentration was reduced in vivo but recovered in vitro. Diaphragmatic oxygen consumption was reduced in vitro at rest and during stimulation. The results suggest that endotoxemic shock results in diaphragmatic fatigue in a time-dependent fashion, that impaired neural or neuromuscular transmission is present in vitro, and that impaired oxygen consumption in the shocked diaphragm is associated with reduced high-energy-phosphate stores.

Adenosine Triphosphate↗
PubMed2002

Spirometry in the supine position improves the detection of diaphragmatic weakness in patients with amyotrophic lateral sclerosis.

STUDY OBJECTIVES: To determine which respiratory function tests best predicted diaphragmatic strength in patients with amyotrophic lateral sclerosis. PATIENTS AND METHODS: Patients referred for pulmonary evaluation were included (n = 25) if they underwent measurement of transdiaphragmatic pressure (Pdi) and one or more of the following on the same day: upright FVC, supine FVC, upright FEV(1), supine FEV(1), maximal inspiratory pressure (MIP), maximal expiratory pressure (MEP), and PaCO(2). Abdominal paradox and use of accessory muscles were also assessed. Bivariate analyses were performed using simple linear regression. Sensitivity and specificity of the potential predictors to detect an abnormal Pdi (< 70 cm H(2)O) were calculated. SETTING: Pulmonary function laboratory of an academic medical center. RESULTS: Upright FVC, FEV(1), and MEP were all significantly correlated with Pdi, while MIP and PaCO(2) were not. Supine FVC was the most highly correlated predictor of Pdi (R(2) = 0.76). A cutoff of supine FVC that was < 75% predicted was 100% sensitive and specific for predicting an abnormally low Pdi. Accessory muscle use and abdominal paradox were both significantly associated with Pdi, and the presence of accessory muscle use had a sensitivity of 84% and a specificity of 100% for detecting a low Pdi. CONCLUSIONS: Our findings suggest that supine FVC is an excellent and simple test of diaphragmatic weakness.

Adult↗