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PubMed1990

Pathophysiology of gastroesophageal reflux. Lower esophageal sphincter dysfunction in gastroesophageal reflux disease.

LES dysfunction is the principal mechanism responsible for GER disease. Two main patterns of sphincter dysfunction have been identified: an abnormally high rate of transient LES relaxations, and defective basal LES pressure. Overpowering of a weak LES by pressure transients induced by straining is less common than previously thought, at least under conditions tested thus far. Current evidence suggests that LES dysfunction results primarily from defective neural control, although smooth muscle function may also be impaired. Extrinsic mechanisms, particularly the diaphragmatic crura, also appear to be important during straining. The role of hiatus hernia remains unclear but seems likely to contribute to the pathogenesis of reflux disease by impairing LES function.

Deglutition↗

PubMed1981

Detection of diaphragmatic fatigue in man by phrenic stimulation.

Transdiaphragmatic pressure (Pdi) was measured at functional residual capacity (FRC) in four normal seated subjects during supramaximal, supraclavicular transcutaneous stimulation of one phrenic nerve (10, 20, 50, and 100 Hz--0.1 ms duration) before and after diaphragmatic fatigue, produced by breathing through a high alinear inspiratory resistance. Constancy of chest wall configuration was achieved by placing a cast around the abdomen and the lower one-fourth of the rib cage. Pdi increased with frequency of stimulation, so that at 10, 20, and 50 Hz, the Pdi generated was 32 +/- 4 (SE), 70 +/- 3, and 98 +/- 2% of Pdi at 100 Hz, respectively. After diaphragmatic fatigue, Pdi was less than control at all frequencies of stimulation. Recovery for high stimulation frequencies was complete at 10 min, but at low stimulation frequencies recovery was slow: after 30 min of recovery, Pdi at 20 Hz was 31 +/- 7% of the control value. It is concluded that diaphragmatic fatigue can be detected in man by transcutaneous stimulation of the phrenic nerve and that diaphragmatic strength after fatigue recovers faster at high than at low frequencies of stimulation. Furthermore, it is suggested that this long-lasting element of fatigue might occur in patients with chronic obstructive lung disease, predisposing them to respiratory failure.

Adult↗

PubMed1987

Phrenic nerve paralysis after pediatric cardiac surgery. Retrospective study of 125 cases.

Phrenic nerve paralysis was diagnosed in 125 children (1.6%) from a series of 7,670 cardiac surgical procedures in infants and children during a 12 year period. The incidence was 1.9% for open heart and 1.3% for closed heart operations. In order of decreasing incidence, the open heart procedures included Mustard procedure (6.7%), right ventricular outflow tract reconstruction (5.6%), and repair of tetralogy of Fallot (2.7%). The closed heart procedures included Glenn anastomosis (6.2%), Blalock-Hanlon atrial septectomy (5.9%), and right Blalock-Taussig shunt (5.1%). Procedures following previous operations or thoracotomies had almost twice the incidence of phrenic nerve paralysis: Mustard procedure 9.9%, right ventricular outflow tract reconstruction 10.8%, and tetralogy repair 5.5%. Seven patients (5.6%) with phrenic nerve paralysis died. Patients less than 2 years old with phrenic nerve paralysis were intubated for 0 to 57 (average 15.7) days after their cardiac operations and those over 2 years old for 13 to 35 (average 7.2) days (p less than 0.001). Twelve patients had diaphragmatic plication without mortality and were extubated 0 to 6 (average 2.3) days after plication. We have made the following conclusions: (1) Phrenic nerve paralysis may occur after both open and closed cardiac procedures and is more common in children requiring reoperation; (2) it is associated with considerable morbidity; (3) eventual recovery of phrenic nerve function occurs in 84% of children; and (4) diaphragmatic plication is safe, reliable, and of most value in patients who are under 2 years of age and require mechanical ventilation for more than 2 weeks.

Adolescent↗

PubMedDate not supplied

An unusual cause of dyspnea in a patient with relapsing breast cancer.

Bilateral diaphragmatic paralysis (BDP) is usually caused by anatomic lesions of both phrenic nerves or generalized neurologic diseases. BDP has also been observed during and after infections, associated with mediastinal tumors, or may have an idiopathic etiology. A 57-year-old woman with breast cancer had progressive dyspnea that worsened when in the supine position. Lung function tests and phrenic nerve stimulation revealed bilateral diaphragmatic paralysis. Clinical suspicion of BDP should always be raised in patients suffering from progressive dyspnea and orthopnea. Determination of (VC) when standing and in the supine position and measurement of trandiaphragmatic pressure should reveal this uncommon diagnosis.

Adenocarcinoma↗

PubMed1994

Respiratory muscle function in patients with asbestos-related pleural disease.

The effect of asbestos-related pleural disease (ARPD) on the generation of maximum respiratory pressure was investigated in 11 male patients with ARPD mean age 57 years, range 45-74, and mean duration of asbestos exposure of 9.9 years, range 5-16. There were three smokers, seven ex-smokers and one non-smoker. Breathlessness ranged from grade 1-3 on the MRC score. The extent of pleural disease was calculated using a score based on the ILO score for pleural disease. Full respiratory function tests, global respiratory muscle strength and diaphragmatic strength were assessed. Respiratory muscle strength, including diaphragm strength, was normal. Recoil pressure was high or at the upper limit of normal in four patients and correlated with chest radiograph score for pleural disease (r = 0.65, P < 0.02). There was no difference in either global respiratory muscle or diaphragmatic strength between patients with and without involvement of one or both costophrenic angles or between patients with mild or severe breathlessness. We conclude that respiratory muscle strength is not importantly reduced in ARPD, and it is unlikely that weakness contributes to breathlessness in these patients. By contrast reduced chest wall compliance is likely to be an important factor in breathlessness in some cases.

Aged↗

PubMed1998

[Pulmonary hypoplasia in adults: embryology, clinical presentation and diagnostic methods. Our experience and review of the literature].

We report five patients diagnosed of pulmonary hypoplasia (PH) in adulthood (age > 18 years, range 45 to 67 years). PH was left-sided in four cases. The malformations found were 2 cases of renal agenesis, 2 diaphragmatic hernias and 1 hiatal hernia. Lung function data were FEV1 0.88 +/- 0.32 L; FVC 1.30 +/- 0.52 L; FEV 1/FVC 68.5 +/- 5%. Arterial gases (with FiO2 0.21) were PaO2 63.6 +/- 24 and PaCO2 47.1 +/- 11.2 mmHg. Three cases were referred for monitoring of respiratory insufficiency (2 requiring home oxygen therapy) and two for radiographic study of chest disease. The diagnoses were made by computerized tomography (CT) of the chest. Congenital diseases due to underdeveloped lungs in the pseudoglandular phase are rarely diagnosed in adults (48 cases, including ours, have been found in the literature), and PH is rarely diagnosed, possibly because the anomalies observed are attributed to old infections. Clinical presentation is highly variable, depending in large measure on a history of smoking and repeated respiratory infections. Chest CT is at present the diagnostic tool of choice.

Aged↗

PubMed1999

Modified Campbell diagram to assess respiratory muscle action in speech.

Ten normal and four moderate to severe stutterers participated in the study. Pleural (Ppl) and abdominal (Pab) pressure was studied using oesophageal and gastric balloon catheter systems and VL (VL) was studied using magnetometry. The classical Campbell diagram was modified by plotting Pab versus VL. In a preliminary study we determined whether a surrogate curve could be substituted for the true curve in the Campbell diagram. We obtained true relaxation curves in six subjects. We obtained surrogate chest wall relaxation curves by joining the Pab value at functional residual capacity (FRC) to a point on the dynamic expiratory Pab, VL curve where Pab had decreased to half its maximum inspiratory excursion. In order to obtain the mirror image of the elastic recoil curve of the lung subjects breathed slowly from FRC to total lung capacity. Dynamic Pab, VL and Ppl, VL measurements during quiet breathing and speech were superimposed on static lung and chest wall curves. The simultaneous plot of Ppl and Pab provided a continuous measure of transdiaphragmatic pressure as a function of VL. We inferred non-diaphragmatic muscle recruitment vis-à-vis the diaphragm by the relationship of Pab to Ppl and Pab to the relaxation curve. We compared dynamic Ppl during phonation with that during breath-holding with the glottis open at the same VL, as an estimate of subglottic pressure (Psg). Analysis of variance testing showed that the true, surrogate and predicted relaxation slopes were not significantly different. The strategies that stutterers used to speak were either higher or lower VL than normal subjects and they had a different pattern of respiratory muscle recruitment. Stutterers were unable to achieve the appropriate degree of recruitment to develop and maintain a normal Psg for conversational speech and this contributed to dysfluency. We conclude that the quiet breathing loops can provide a reasonable approximation to the relaxation curve in normal healthy subjects and that modifications to the Campbell diagram provide useful means of measuring Psg and assessing respiratory muscle recruitment patterns.

Adolescent↗

PubMed1988

Evaluation of time interval difference digital subtraction fluoroscopy in patients with cystic fibrosis.

In this study the potential of thoracic subtraction fluoroscopy has been evaluated on the basis of our experience with this functional imaging modality in patients presenting with cystic fibrosis. The method, which consists of subtracting dynamic digital fluoroscopic images of the breathing chest in the time interval difference (TID) mode, applies to the study of the lucency variations during the respiratory cycle and provides dynamic functional information about ventilation and/or perfusion and diaphragmatic kinetics, without any injection and with minimal irradiation. To assess the validity of the TID procedure, our results were compared with standard roentgenography, clinical data, and scintigraphic findings, with emphasis on the latter. The limitations and advantages of TID compared with scintigraphy are discussed. Three groups of discrepancies emerge which do not discredit TID. TID offers rather the advantage of providing anatomic pictures and unique dynamic information, which is emphasized.

Cystic Fibrosis↗

PubMed1993

[Diaphragmatic electrostimulation in bronchial asthma patients].

A study was made of the effect of transcutaneous diaphragmatic electrostimulation (DES) on the external respiratory function (ERF) and central hemodynamics (CH) in 36 asthmatic patients. The ERF and CH were examined by microprocessor spiroanalyzers and rheography. DES (2 mA, 0.3 ms, 20-30 v, frequency 13-17 imp/min) was performed for 7 days, 20 minutes daily. The improvement in respiratory function parameters and a positive clinical effect were achieved in the majority of patients, especially in asthmatic patients with respiratory insufficiency. The parameters of CH did not noticeably changed.

Adult↗

PubMed1993

Ultrastructural features of alveolar epithelial cells in the late fetal pulmonary acinus: a comparison between normal and hypoplastic lungs using a rat model of pulmonary hypoplasia and congenital diaphragmatic hernia.

The aim of this study was to describe and compare the ultrastructural features and functional maturity of alveolar epithelial cells in hypoplastic and normal fetal rat lungs. Pulmonary hypoplasia in association with congenital diaphragmatic hernia was induced in fetuses by administration of 2,4-dichlorophenyl-p-nitrophenylether (Nitrofen) to pregnant Sprague Dawley rats (100 mg on day 10 of gestation). Lung tissue of Nitrofen-exposed and control fetal rats aged 19-22 days (vaginal plug day 1, birth day 23) was embedded in Epon. Semithin (1 micron) toluidine blue-stained sections were examined by light microscopy; ultrathin sections (approximately 80 nm) were studied via transmission electron microscopy. In bronchoalveolar lavage fluid from control and Nitrofen-exposed fetuses (day 22), phospholipid fractions and surfactant protein A content were measured semiquantitatively. On day 19 both control and Nitrofen-exposed lungs contained only cuboid alveolar epithelial cells; from day 20 there were cuboid, low cuboid, and thinner epithelial cells. The (low) cuboid cells contained large glycogen fields, some precursory stages of multilamellar bodies (MLBs), and just a few mature MLBs on day 19 and 20; smaller glycogen fields, more precursory stages, and more mature MLBs on day 21; and little or no glycogen but many precursory stages and mature MLBs on day 22. The thinner cells contained little or no glycogen and a few precursory stages of MLBs on days 20-22; very thin cells on day 22 contained neither glycogen nor any precursory stages of MLBs. MLBs and tubular myelin were seen in the lumens of future air spaces from day 20 onward. Nitrofen-exposed lungs differed from control lungs in that inclusion bodies (IBs) were less numerous in (low) cuboid alveolar cells on days 19 and 20, and more glycogen was seen on day 22. In addition intra- and extracellular "MLBs" in exposed lungs more often had an unusual appearance, i.e., a confluent structure and higher electron density. However, despite morphologic differences, there was no clear difference in phospholipid composition and SP-A content per mol phospholipid in bronchoalveolar lavage fluid. We conclude that morphologically hypoplastic lungs are less mature near term, without an apparent effect on surfactant composition.

Animals↗

PubMed2002

Diaphragm plication following phrenic nerve injury: a comparison of paediatric and adult patients.

BACKGROUND: A study was undertaken to evaluate whether adults differ from children in the indications and outcome of diaphragmatic plication following phrenic nerve injury. METHODS: A retrospective study was performed of 21 patients, 10 below the age of 5 and 11 older than 37 years. The indication for surgery for all the children was failure to wean from ventilatory support. The indications for surgery in the adult group were ventilator dependency (n=4) and symptomatic dyspnoea (n=7). All patients had at least one imaging study confirming diaphragmatic paralysis. The American Thoracic Society (ATS) dyspnoea scale, pulmonary function tests, and quantitative pulmonary perfusion scans were used as evaluation parameters. At surgery the diaphragm was centrally plicated. RESULTS: One child died immediately after surgery due to irreversible heart failure and two children died within 2 months of surgery from ongoing complications of their original condition. These three patients were considered as selection failures. Seven children were weaned from ventilatory support within a median of 4 days (range 2-140). Only one of four ventilated adults was successfully weaned. Seven adults who underwent surgery for chronic symptoms had a marked subjective improvement of 2-3 levels in the ATS dyspnoea scale. Pulmonary function studies in the seven symptomatic adults showed a 40% improvement above baseline. Severely asymmetrical perfusion scans reverted to a normal pattern after plication. CONCLUSIONS: Diaphragmatic plication offers a significant benefit to children with diaphragmatic paralysis and should be performed early to facilitate weaning from mechanical ventilation. While plication is of limited benefit in weaning ventilated adults, it results in significant subjective and objective lifetime improvement in non-ventilated symptomatic adults.

Adult↗

PubMed1991

Extracorporeal membrane oxygenation treatment. One-year outcomes for North Carolina infants.

Initial survival rates for the first 45 North Carolina ECMO neonates in the study group are somewhat better than national figures. Developmental functioning as assessed at one year of age is comparable to that reported in other studies. A congenital diaphragmatic hernia diagnosis was significantly related to poorer outcome. Measures of family functioning approximate those reported for families of non-ECMO neonates treated in intensive care. Support provided by ECMO staff was rated at a notably high level. With nearly three thousand survivors and multiple numbers of ECMO centers now operating in this country, ECMO has made the transition from an experimental treatment to an established procedure for treatment of neonates in pulmonary failure. A few beginning attempts to utilize ECMO with older patients are being made. Neonatologists are now directing efforts toward refining techniques and selection criteria. Further evaluation of longer-term effects of this type of treatment is essential. Effective protocols for follow-up care need to be designed, particularly for those at greatest risk for developmental disability.

Child↗

PubMed2003

[Relationship between Hoover sign, functional and variables, and curvature radius in patients with obstructive pulmonary disease].

The purpose of the present study was: 1) to relate the Hoover sign -SH (+)- with several functional (spirometry and lung volumes) and radiographic (AP x-ray) parameters, 2) to characterize the changes in diaphragmatic curvature radius and the efficiency and to establish some relationships with the functional and radiographic parameters. Fifteen patients with COPD (SH (+), n: 8) were studied. The radius was determined in the right hemidiaphragm after maximal inspired and expired x-ray. The SH (+) was found in more severely obstructed patients (FEV1%, p 0.005%) and with high degree of air trapping (RV/TLC %, p 0.01). The expiratory radius (Re) was higher (p 0.05), and their efficiency (1/Re), was minor (p 0.05). The FEV1% correlated with the degree of hyperinflation according to TLC % (r -0.58, p 0.022) and with air trapping according to RV % (r -0.77, p 0.0008). The patients with low FEV1% showed high Re (r -0.61, p 0.015) and decreased diaphragmatic efficiency during expiration (1/Re) according to 1/Re = 0.093 cm-1 + 0.0012 cm-1* FEV1% (r 0.688, p 0.0054). The FEV1 correlated with the diaphragmatic movement (r 0.71, p 0.003). The PaCO2 correlated with the TLC % (r 0.534, p 0.04), the RV% (r 0.62, p 0.014) and with the radiographic parameters of hyperinflation (r 0.546, p 0.035) and air trapping (r 0.528, p 0.043). The presence of Hoover sign suggest severe bronchial obstruction, diaphragmatic flattening, increase of curvature radius, decrease of mobility and efficiency.

Aged↗

PubMed2004

Three-dimensional ultrasonographic assessment of fetal lung volume as prognostic factor in isolated congenital diaphragmatic hernia.

OBJECTIVE: To evaluate the potential of three-dimensional ultrasound to predict outcome in congenital diaphragmatic hernia. DESIGN: Prospective observational study. SETTING: Tertiary care centre. POPULATION: Twelve cases of isolated congenital diaphragmatic hernia (11 left-sided, 1 right-sided) and 109 controls. METHODS: Fetal lung volume was assessed by three-dimensional ultrasound using the technique of rotation of the multiplanar imaging. In the control fetuses, a logistic transformation was performed to correlate fetal lung volume with gestational age, and the confidence interval was obtained with a bootstrap resampling. A mathematical equation was then obtained allowing calculation of the expected fetal lung volume as a function of gestational age. In fetuses with congenital diaphragmatic hernia, the observed/expected lung volume ratio was compared with postnatal outcome. MAIN OUTCOME MEASURES: Neonatal mortality and pulmonary hypoplasia, which was defined as lung/body weight ratios less than 0.012. RESULTS: The expected fetal lung volume was derived from the mathematical equation: Fetal lung volume (mL) = exp (4.72/(1 + exp ((20.32 - gestational age in weeks)/6.05))). The observed/expected fetal lung volume ratio was significantly lower in the congenital diaphragmatic hernia group (median: 0.34, range: 0.16-0.66), than in the control group (median: 1.02, range: 0.62-1.97, P < 0.0001). The distribution of this ratio was significantly downshifted in the infants with congenital diaphragmatic hernia who died (median: 0.19, range: 0.18-0.66) compared with survivors (median: 0.44, range: 0.36-0.66, P= 0.04). The observed/expected fetal lung volume ratio was also correlated with the postmortem lung/body weight ratio. CONCLUSION: In isolated congenital diaphragmatic hernia, fetal lung volume measurement by three-dimensional ultrasound is a potential predictor for pulmonary hypoplasia and postnatal outcome.

Female↗

PubMed1988

Radiographic measures of hyperinflation in clinical emphysema. Discrimination of patients from controls and relationship to physiologic and mechanical lung function.

In a retrospective study we investigated the accuracy of radiographic measurements of hyperinflation in distinguishing a sample of patients with a clinical diagnosis of pulmonary emphysema (n = 44) from a sample of age- and sex-matched control subjects (n = 39). The relationship of the hyperinflation parameters to pulmonary function test results (PFTs) and arterial blood gas measurements (ABGs) in the emphysema patients was also examined. The radiographic measurements were diaphragmatic angle of depression, lung height, lung width, heart size, diaphragm level, radiographic total lung capacity (TLC), and size of the retrosternal air space. By discriminant function analysis, the best contributors to the function were lung height and diaphragmatic angle of depression, followed by radiographic TLC and heart size. The derived classification rule had a diagnostic accuracy of 88 percent. The radiographic measures, largely independent of one another, showed moderate correlations with percentage PFTs, ABGs, portable percentage spirometric studies, height, and weight. High correlations were found between several of the radiographic measurements and the PFTs that represent actual static lung volumes. The correlation between radiographically measured TLC and PFT TLC measured by the helium dilution technique was .90.

Female↗

PubMed1997

A case of unilateral diaphragmatic eventration treated by plication with thoracoscopic surgery.

A 56-year-old woman underwent plication with U-stitches by thoracoscopic surgery for left diaphragmatic eventration. Marked improvement in left lung expansion, normalization of the position of the left diaphragm on chest radiograph, and improvement of pulmonary function and dyspnea on exertion have been maintained for 2 years. Plication for diaphragmatic eventration should be performed with minimally invasive surgery.

Diaphragmatic Eventration↗

PubMed2003

A prospective, randomized pilot trial of perfluorocarbon-induced lung growth in newborns with congenital diaphragmatic hernia.

BACKGROUND/PURPOSE: Initial laboratory and clinical data suggest that partial liquid ventilation (PLV) can enhance pulmonary function and that lung growth can be induced via distension of the newborn lung using perfluorocarbon in patients with congenital diaphragmatic hernia (CDH). The authors, therefore, performed a prospective, randomized pilot study evaluating PLV and perfluorocarbon-induced lung growth (PILG) in newborns with CDH on extracorporeal life support (ECLS) at 6 medical centers. METHODS: Patients were selected randomly using a permuted block design to PLV/PILG (n = 8) or conventional mechanical ventilation (CMV/control, n = 5). Patients in the PILG group received daily doses which filled the lungs with perflubron for up to 7 days and were placed on continuous positive airway pressure of 5 to 8 cm H2O. CMV patients were treated with standard mechanical ventilation while on extracorporeal membrane oxygenation (ECMO). RESULTS: A total of 13 patients were evaluated in this study. All 3 patients enrolled without being on ECLS rapidly transitioned to ECLS. The study, therefore, effectively evaluated PILG (n = 8) versus standard ventilation (control, n = 5) on ECLS. Mean (+/- SE) gestational age was 37 +/- 1 weeks and weight was 3.1 +/- 0.1 kg. Time on ECMO was 9.8 +/- 2.3 days in the PILG and 14.5 +/- 3.5 days (P =.58) in the control group. Survival rate in the PILG group was 6 of 8 (75%), whereas survival rate was 2 of 5 (40%) in the control group (P =.50). The number of days free from the ventilator in the first 28 days (VFD) was 6.3 +/- 3.3 days with PILG and 4.6 +/- 4.6 days with control (P =.9). Causes of death in the PILG group included sepsis and renal failure in one patient and pulmonary hypertension in the other. There were no safety issues, and the deaths in the PILG group did not appear to be related to the administration of perflubron. CONCLUSIONS: These data show that PILG can be performed safely. The survival rate, VFD, and time on ECMO data, although not conclusive, are encouraging and indicate the need for a definitive trial of this novel intervention in these neonates with high mortality.

Combined Modality Therapy↗

PubMed2002

Motion of the diaphragm in patients with chronic obstructive pulmonary disease while spontaneously breathing versus during positive pressure breathing after anesthesia and neuromuscular blockade.

BACKGROUND: Diaphragmatic excursion during spontaneous ventilation (SV) in normal supine volunteers is greatest in the dependent regions (bottom). During positive pressure ventilation (PPV) after anesthesia and neuromuscular blockade and depending on tidal volume, the nondependent region (top) undergoes the greatest excursion, or the diaphragm moves uniformly. The purpose of this study was to compare diaphragmatic excursion (during SV and PPV) in patients with chronic obstructive pulmonary disease (COPD) with patients having normal pulmonary function. METHODS: Twelve COPD patients and 12 normal control subjects were compared. Cross-table diaphragmatic fluoroscopy was performed while patients breathed spontaneously. After anesthetic induction and pharmacologic paralysis and during PPV, diaphragmatic fluoroscopy was repeated. For analytic purposes, the diaphragm was divided into three segments: top, middle, and bottom. Percentage of excursion of each segment during SV and PPV in normal subjects was compared with the percentage of excursion of each segment in patients with COPD. RESULTS: There was no significant difference in the pattern of regional diaphragmatic excursion (as a percentage of total excursion)-top, middle, bottom-when comparing COPD patients with control subjects during SV and PPV. In the control subjects, regional diaphragmatic excursion was 16 +/- (5), 33 +/- (5), 51 +/- (4) during SV and 49 +/- (13), 32 +/- (6), 19 +/- (9) during PPV. In COPD patients, regional diaphragmatic excursion was 18 +/- (7), 34 +/- (5), 49 +/- (7) during SV and 47 +/- (10), 32 +/- (6), 21 +/- (9) during PPV. CONCLUSION: Regional diaphragmatic excursion in patients with COPD during SV and PPV is similar to that in persons with normal pulmonary function.

Aged↗