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PubMed1983

Chest wall stiffness in patients with chronic respiratory muscle weakness.

Using the weighted spirometer technique we studied chest wall compliance (Cw) in 16 nonobese patients with chronic weakness of the respiratory muscles and 20 healthy control subjects. In order to evaluate the validity of the technique, while Cw was being measured, we monitored thoracoabdominal configuration with 2 pairs of linearized magnetometers and electrical activity of the external oblique with a concentric needle electrode in 3 healthy subjects and 4 patients; in addition, we recorded in 3 subjects the electrical activity from the intercostal muscles and diaphragm throughout the procedure. The method was reproducible within 5.8% and provided Cw values that compared well with those yielded by the relaxation technique. In each subject, the weight-induced shifts in end-expiratory lung volume showed a very good linear correlation with the changes in transrespiratory pressure at end-expiration (r greater than or equal to 0.91). In addition, in none of the subjects tested did the electromyograms reveal any intercostal, diaphragmatic, or abdominal muscle activity at end-expiration, nor did the end-expiratory level ever show a significant departure from the relaxed thoracoabdominal configuration, thus suggesting adequate respiratory muscle relaxation. The reduction in inspiratory muscle force in the patients ranged from 17 to 94% of predicted (mean +/- SE, 43 +/- 6). The decrease in vital capacity, total lung capacity, and functional residual capacity averaged 59, 34, and 15% of predicted, respectively. Both the patient and the control groups showed a large interindividual variability regarding Cw. It varied from 0.117 to 0.258 L/cm H2O (mean +/- SE, 0.162 +/- 0.012) in the patients and from 0.163 to 0.366 L/cm H2O (mean +/- SE, 0.248 +/- 0.013) in the healthy subjects.(ABSTRACT TRUNCATED AT 250 WORDS)

Abdominal Muscles↗
PubMedDate not supplied

[Ways to reduce mortality of newborns with developmental defects].

Technological progress contributed to progress in surgery on the newborns. However, despite the progress in surgery and intensive care of the newborns, the results of treatment of patients with congenital defects are sometimes disappointing. The priority problems for today are the respiratory distress syndrome, hemodynamic disorders, and renal dysfunction, which can be united into the syndrome of general dysadaptation of the newborns. Based on experience gained in the treatment of newborns in pediatric surgical hospital, protocols of treating newborns with developmental defects (congenital diaphragmatic hernia, esophageal atresia, and gastroschisis) have been developed. These protocols are a stage and a prerequisite for development of more effective methods for treating such patients. Common intensive care should be supplemented by such important measures as maintenance of adequate temperature regimen at all stages of medical transportation and therapy of a newborn, obligatory preoperative preparation for stabilization of vital functions, multicomponent endotracheal anesthesia, use of inotropic agents (dopamine and dobutrex), synchronic prolonged artificial ventilation of the lungs and prolonged analgesia, limitation of indications to the use of blood preparations and wide use of hydroxyethylated starch solutions in infusion therapy, rational antibiotic therapy with constant monitoring of the microecological status, and early detection and correction of concomitant diseases. Solution of these problems will essentially decrease the postoperative mortality of newborns with developmental defects.

Analgesia↗
PubMed1992

[An unusual case of annular constrictive pericarditis--a "framed heart"].

We presented a 62-year-old female with constrictive pericarditis of an unusual anatomy. A calcified constrictive band, 2-3 cm wide, ran parallel to the frontal plane, coursing circularly along the anterior aspect of the great arteries, right atrium, diaphragmatic surface of the right ventricle, posterolateral aspect of the left ventricle and back to the great arteries. The course of the constrictive band was circular but completely different from that of typical annular constrictive pericarditis in which a constrictive band runs along the atrioventricular groove. Hemodynamic consequences of our patient was rather non-specific impairment of ventricular filling than functional valvular stenoses due to external compression characteristic for the typical annular constrictive pericarditis. Effective surgical relief of the constriction was accomplished under cardiopulmonary bypass and cardioplegic cardiac arrest.

Calcinosis↗
PubMed2002

The influence of ductal left-to-right shunting during extracorporeal membrane oxygenation.

BACKGROUND/PURPOSE: The aim of this study was to analyze whether a ductal left-to-right (L-R) shunt will prolong extracorporeal membrane oxygenation (ECMO) in neonates with severe pulmonary hypertension. This report discusses the onset and termination of a ductal L-R shunt and its potential influences on ECMO when pulmonary hypertension decreases during venoarterial bypass. METHODS: Twenty-nine neonates were monitored during veno-arterial ECMO, using bedside echocardiography with 12-hour interval observations. RESULTS: Up to 43% of the patients showed this type of shunt already after 12 hours on bypass. In total, this type of ductal shunt was found between 12 and 72 hours on ECMO in 62% of the patients. After 72 hours, the ductal L-R shunt no longer was detected. In 38% of the patients, no ductal L-R shunt was found during ECMO. Comparisons between these 2 patient groups showed a significantly longer ECMO duration in patients with ductal L-R shunt (P <.007). The mean prolongation time was 46 hours. Also, a significant decrease of left atrium to aorta ratio (P <.01) was observed during ECMO in the ductus group after closure of the duct, illustrating the decrease in volume load for the left heart and lungs. CONCLUSIONS: Ductal L-R shunting is related with a substantial prolongation of the ECMO course (mean prolongation of almost 2 days). The authors suggest that on one side, the ductal L-R shunt will lead to pulmonary hypercirculation and on the other side, postductal stealing from the descending aortic circulation will lead to prerenal failure. Possibly because of interactions with pulmonary and renal function, a ductal L-R shunt will, among other factors, interfere with weaning from ECMO, resulting in a prolonged bypass time.

Echocardiography↗
PubMedDate not supplied

[Echocardiographic evaluation of asynergy of the left ventricle in the early stages of acute myocardial infarct and its value in predicting infarct complications].

The authors report on their experience with the semiquantitative echocardiographic evaluation of left ventricular asynergy (group of 36 patients examined by two-dimensional echocardiography, dividing the left ventricle into 20 segments) in the early stage of myocardial infarction and its application in the prediction of complications of infarction. The authors evaluated asynegry using two parameters: RA (range of asynergy and IA (asynergy index) which characterizes the grade of ventricular affection. They describe the calculation of these parameters. The authors revealed a significant correlation (p less than 0.005) between RA or IA and the incidence of decompensation or cardiogenic shock. RA and IA values (median values and scatter) in three groups of patients (non-complicated infarction, complicated infarction and infarction with cardiogenic shock and death) give the opportunity of early stratification of patients with acute infarction. RA above 50% and IA above 20 indicate that the patients is at high risk. On the other hand, RA lower than 25% and IA lower than 5 suggest a minor infarction and probably an uncomplicated course of the disease. In the investigated group anterior infarctions affected a greater mass of the left ventricle than diaphragmatic ones and the higher death rate in this group (20% vs. 14%) was consistent with this.

Adult↗
PubMed2001

Decreased mitogen activated protein kinase activities in congenital diaphragmatic hernia-associated pulmonary hypoplasia.

BACKGROUND/PURPOSE: The mechanisms that cause pulmonary hypoplasia associated with congenital diaphragmatic hernia (CDH) currently are unknown. The authors proposed that the reduced size and immaturity of these lungs may be associated with differences in the levels of mitogen activated protein (MAP) kinase phosphorylation (extracellular signal regulated protein kinases, ERK-1 and -2). METHODS: ERK-1 activities were measured using immune-complex kinase assays on fetal whole-lung lysates obtained from both nitrofen and olive oil-treated (control) pregnant rats. In addition, ERK-1 and ERK-2 functional activities were estimated by semiquantitative Western blot analysis, using an antibody specific for the diphosphorylated (dp-ERK, activated) forms of the enzymes. RESULTS: ERK-1 activities, measured using immune-complex kinase assays, were reduced in CDH lungs compared with olive oil-treated controls (P <.02). In addition, dp-ERK-1 and dp-ERK-2 levels were found to be reduced in CDH lungs compared with controls (dp-ERK-1, P =.003; dp-ERK-2, P =.04), whereas ERK-1 and ERK-2 protein levels were unchanged. CONCLUSIONS: The lower values of ERK-1 activity and reduced amounts of dp-ERK-1 and dp-ERK-2 in lung tissue from CDH animals, suggests that ERK-1 and ERK-2 activities are reduced in pulmonary hypoplasia associated with CDH. The observed reduction in ERK-1 and ERK-2 activities implicates attenuated cell signaling upstream of the ERK-1 and -2 enzymes.

Animals↗
PubMed1998

Analysis of patients with congenital diaphragmatic hernia requiring pre-operative extracorporeal membrane oxygenation (ECMO).

The purpose of this report was to analyze the patients requiring preoperative extracorporeal membrane oxygenation (ECMO) as the most critical group of patients with congenital diaphragmatic hernia (CDH) and to identify any special features. Over the past 11 years, out of 72 neonates with CDH admitted before 24 h of age, 40 (56%) could be managed with conventional therapies while the other 32 (44%) required ECMO. Seventeen infants requiring preoperative ECMO were classified as group 1, and the 15 with postoperative ECMO as group 2 (controls). The records of patients in both groups were analyzed. Patients in group 1 were not only severely hypoxic, but also significantly hypercapneic on admission, and in 14 (82%) the diaphragmatic defect was so large or totally agenetic that a prosthetic patch was necessary. The average age at onset of ECMO in group 1 was 13.1 h, and the average duration was 159 h. Major hemorrhagic complications including intracranial hemorrhage occurred with a significantly higher frequency in group 1. The survival rate in group 1 was 41%, compared with 73% in group 2 and 85% in non-ECMO patients. Four infants in group 1 with extremely hypoplastic lungs could not be weaned from ECMO, and died without undergoing an operation. Moreover, 4 of the 7 survivors in group 1 required prolonged (105-658 days) ventilator care with a tracheostomy after weaning from ECMO, and were frequently hospitalized thereafter. The pulmonary function of these patients remained severely underdeveloped for a long time; indeed, the average pulmonary perfusion ratio of the affected side remained at only 40% of the contralateral side in group 1, although the volume ratio reached 85%. These findings may suggest that the main pathology of the patients requiring preoperative ECMO was a high degree of pulmonary hypoplasia, and that there will be limitations to management using ECMO.

Extracorporeal Membrane Oxygenation↗
PubMed1979

Sinus arrest in diaphragmatic myocardial infarction: treatment of power failure with atrial pacing.

Sinus arrest occurred in a patient with acute diaphragmatic myocardial infarction associated with right ventricular infarction. Cardiac output fell dramatically despite maintenance of a junctional rate of 72. Ventricular pacing at rate 82 and dopamine administration resulted in only slight hemodynamic improvement. Atrial pacing at rate 84 restored normal cardiac output until resumption of sinus node activity. These results suggest that atrial contraction is important for the maintenance of ventricular function in some patients with acute infarction, and may be of particular importance in the presence of right ventricular infarction. Temporary atrial or atrioventricular sequential pacing may be of great hemodynamic benefit in selected patients with conduction defects complicating myocardial infarction.

Cardiac Pacing, Artificial↗
PubMed1988

Efficiency of work of inspiratory muscles in standing and in exercising dogs.

The objective of this study was to elucidate the resistive, elastic, and total inspiratory muscle work and mainly the efficiency of the inspiratory muscle work in still standing and in exercising dogs. In 180 experiments with nine mongrel dogs, respiratory and circulatory functions were recorded at rest and during a 1.5-mph walk on a treadmill belt which was inclined by 9 degrees. Each dog had been trained and surgically prepared before the series of experiments started. An electronic pressure transducer together with a fluid-filled catheter was attached to the ribs at the midthoracic level. Airflow was monitored with a pneumotachygraph attached to a face mask. Aortic flow was monitored with an electromagnetic flow transducer. Catheters in the atria, the ventricles, and the pulmonary and systemic vessels were used to determine hemodynamic parameters and blood gas levels. All recorded and all derived functions were evaluated by a dedicated computer. At rest, resistive inspiratory work (0.98 kg cm) was smaller than elastic work (1.36 kg cm). Elastic work did not change with exercise but resistive work increased to 1.46 kg.cm. The increase of total work from 2.33 kg.cm at rest to 2.79 kg.cm during exercise did not reach significance. Inspiratory power increased with exercise. Estimated diaphragmatic oxygen consumption increased from 2.23 ml/min at rest to 3.64 ml/min during exercise. It was 1.6 percent of the total oxygen consumption at rest and 1.7 percent of the total oxygen consumption during exercise. The estimated efficiency of the work of inspiratory muscles was 15.8 percent at rest and 25.8 percent during exercise. These values did not vary substantially between different animals.

Animals↗
PubMed1986

Effects of prenatal nitrofen exposure on cardiac structure and function in the rat.

The herbicide nitrofen was administered to pregnant Fischer-344 and Sprague-Dawley rats on Days 10-13 of gestation (po, 20 or 40 mg/kg daily) and its effects on cardiac structure and function were investigated in the offspring. In the 21-day fetuses, nitrofen did not influence intrauterine growth or basal heart rate. In contrast, the herbicide produced a marked depression of heart rate and abnormal electrocardiographic (ECG) profiles in the newborn rats, in conjunction with labored respiratory movements and a profound increase in postnatal mortality. A few animals displayed cardiac ventricular septal defects and diaphragmatic hernias but these malformations did not appear to be associated with the ECG changes. The chronotropic deficiencies seen in the nitrofen-treated pups were reversible by acute hyperoxia (40% oxygen). These results suggest that the teratogenic effects of nitrofen on cardiac physiology and on postnatal mortality cannot be accounted for solely by specific gross anatomical damages to the rat heart and diaphragm; rather, other more subtle morphological and physiological factors which contribute to improper systemic delivery and cellular utilization of oxygen may be involved.

Animals↗
PubMed1992

[Myocardial dissection in infarction of the right ventricle. Clinical echocardiographic and pathological aspects].

Dissection of the inferior wall of the right ventricle during the acute phase of myocardial infarction with right ventricular involvement is a mechanical complication which has been recently identified, the diagnosis being almost exclusively post-mortem. The authors report the clinical, echocardiographic and pathological features of myocardial dissection in four patients. Between 1985 and 1988, the diagnosis of myocardial dissection was made by echocardiography in 4 patients aged 77 to 80 years, admitted to hospital for an acute inferior wall myocardial infarction. All 4 patients had signs of acute right ventricular failure indicating right ventricular necrosis and a loud systolic murmur at the left sternal border; 2 patients were in shock. The ECG showed signs of inferior wall infarction with, in 2 patients, electrical changes suggestive of right ventricular involvement. Echocardiography showed dissection of the inferior wall of the right ventricle as a pulsatile, echo-free space in the diaphragmatic wall of the right ventricle which appeared to obstruct right ventricular ejection in end systole to a variable degree. The outcome was fatal in all cases with death resulting from refractory myocardial failure. Pathological analysis confirmed biventricular inferior wall infarction also involving the posterior part of the interventricular system, the site of a small tear on the left side which communicated with a neo-cavity dissecting the RV posterior wall. The right coronary artery was totally occluded in all cases. The anatomical lesions were fully concordant with the echocardiographic data: the dissection filled with blood from the left ventricle at each systole creating a pulsatile space in the diaphragmatic wall of the ventricle obstructing ejection.

Aged↗
PubMed1979

Treatment of hiatal hernia with esophagitis in a patient using esophageal speech after laryngectomy.

Severe reflux esophagitis occurring after total laryngectomy in a patient who has learned to communicate by esophageal speech represents a unique problem in management. It was anticipated that an antireflux operation might interfere with esophageal speech. A Nissen fundoplication resulted in complete resolution of signs and symptoms of reflux esophagitis without compromising esophageal speech. A comparison of pre- and post-operative speech functions suggests that more noticeable changes could result after an antireflux operation in the less proficient speaker and, therefore, only those patients with persistent and unresponsive reflux esophagitis should be operated upon.

Esophagitis, Peptic↗
PubMed1981

[Hiatal hernia, gastroesophageal reflux and the lower esophageal sphincter. Manometric study with the "rapid pull-through method"].

Data obtained by means of rapid pull-through manometry in cases of hiatal hernia with or without gastro-oesophageal reflux are presented. Particular reference is made to lower oesophageal sphincter pressure in reflux symptomatologies irrespective of the presence of hiatal hernia. A relation between age and lower oesophageal pressure was noted. Hypotonia of the sphincter was observed in younger subjects, whose reflux symptoms are more marked and often unassociated with hiatal hernia. In the patients, sphincter dysfunction appears to be related to an error in the neurohormonal control mechanism of this functional complex. Stress is also laid on the rôle of pull-through manometry in the diagnostic, therapeutic and prognostic approach to diseases of this type.

Adult↗
PubMed1995

Pathophysiology of congenital diaphragmatic hernia. XI: Anatomic and biochemical characterization of the heart in the fetal lamb CDH model.

AIM: The purpose of this study was to determine whether the presence of bowel in the chest during development in the fetal lamb model of congenital diaphragmatic hernia (CDH) results in structural and/or biochemical hypoplasia of the left venticle. METHODS: The model was created at 80 days' gestation and delivered at term. The hearts were fixed in 4% formaldehyde solution, components weighed, and right ventricular (RV) and left ventricular (LV) wall thicknesses and both aortic (Ao) and pulmonary artery (PA) root diameters were measured. Fresh specimens were analyzed for protein, DNA, hydroxyproline, and elastin content. All CDH measurements are compared with littermate control tissues. RESULTS: There were no differences in body weight (kg) between CDH and control littermates (4.25 +/- 0.26 versus 3.71 +/- 0.24, P = NS). CDH lambs have significantly decreased total heart (4.88 +/- .25 versus 6.75 +/- .49, P < .05), left ventricular (1.65 +/- .11 versus 2.15 +/- .19, P < .05), septal (1.29 +/- .11 versus 1.99 +/- .21, P < .05), and combined atrial (0.68 +/- .06 versus 1.14 +/- .15, P < .05) weights (g/kg lamb) without differences in RV weights (1.26 +/- .07 versus 1.57 +/- .17, P = NS). LV and RV wall thickness, and Ao root diameters (cm) were found to be identical in both CDH and control lambs. However, PA root diameters (0.47 +/- .01 versus 0.38 +/- .01, P < .005) and ductus arteriosus diameters were increased in CDH (0.35 +/- .01 versus 0.22 +/- .02, P < .005). Total protein, DNA collagen, and elastin content and DNA/total protein ratios were identical in RV and LV in both CDH and control lambs. CONCLUSION: Newborn lambs with left-sided CDH have a significantly lower total heart, LV, septal, and atrial weights without differences of RV weight or ventricular wall thicknesses. Given these findings, the unchanged DNA/protein ratio implies that the left ventricle is hypoplastic in CDH. Ao/PA root ratios suggest that LV hypoplasia in utero may result in increased left atrial pressures, decreased right-to-left shunting through the foramen ovale, and increased PA pressures and flow, resulting in increased PA root and ductus arteriosus diameters. This model simulates the clinical data from human fetuses/neonates with CDH. Further investigations are necessary to determine the functional significance of these findings.

Animals↗
PubMed1988

Effects on respiration of CPAP immediately after extubation in the very preterm infant.

The effects of continuous positive airway pressure (CPAP) on pulmonary function during weaning from ventilator treatment were examined immediately after extubation in 17 very preterm infants, who had been ventilator-treated because of hyaline membrane disease (15 infants) and chronic pulmonary insufficiency of prematurity (two infants). Seven infants had bronchopulmonary dysplasia. Median birthweight was 920 g and median gestational age 26 completed weeks. The median duration of ventilator treatment was 10 days. Application of CPAP by means of a face chamber device after endotracheal extubation significantly lowered the frequency of apnea (P = 0.02) and enhanced oxygenation (P = 0.001). The respiratory mechanical indices derived from flow rate and juxta-diaphragmatic esophageal pressure measurements showed a reduced elastic (P = 0.03) and resistive (P = 0.02) load on the diaphragm. Even if the measured values do not accurately represent absolute resistances and compliances, the relative values of end-inspiratory and end-expiratory pressures differed significantly with and without CPAP (P = 0.001 and 0.002, respectively). We found CPAP applied via the face chamber technique immediately after extubation to be beneficial and to facilitate weaning from ventilator treatment in very preterm infants.

Female↗
PubMed2001

Cardiac gene expression and synthesis of atrial natriuretic peptide in the nitrofen model of congenital diaphragmatic hernia in rats: effect of prenatal dexamethazone treatment.

BACKGROUND/PURPOSE: The aim of this study was to determine the gene and protein levels of atrial natriuretic peptide (ANP) in the heart of nitrofen-induced congenital diaphragmatic hernia (CDH) in rats and to evaluate the effect of antenatal dexamethazone (Dex) treatment. METHODS: CDH model was induced in pregnant rats after administration of 100 mg of nitrofen on day 9.5 of gestation (term, day 22). Dexamethazone (Dex, 0.25 mg/kg) was given by intraperitoneal injection on days 18.5 and 19.5 of gestation. Cesarean section was performed on day 21 of gestation. The fetuses were divided into 3 groups: group I, control (n = 10); group II, nitrofen-induced CDH (n = 10); group III, nitrofen-induced CDH with antenatal Dex treatment (n = 10). ANP protein was measured using enzyme-linked immunosorbent assay (ELISA) technique. Reverse transcription polymerase chain reaction (RT-PCR) was performed to evaluate the relative amount of atrial natriuretic peptide (ANP) mRNA expression. RESULTS: There was a significant reduction in ANP mRNA (P <.05) and protein (P <.01) levels in heart of group II (CDH) compared with group I. Antenatal Dex treatment significantly increased both ANP mRNA and protein levels in the heart of CDH animals (P <.05). CONCLUSIONS: The reduced cardiac ANP gene expression and ANP synthesis indicates that the heart in CDH is functionally immature and may be unable to respond to hemodynamic load accompanying persistent pulmonary hypertension (PPH). ANP or drugs such as steroids, which raise endogenous ANP levels, may have a therapeutic application in CDH complicated by PPH.

Animals↗
PubMed1997

4-Aminopyridine reverses saxitoxin (STX)- and tetrodotoxin (TTX)-induced cardiorespiratory depression in chronically instrumented guinea pigs.

The extent to which cardiorespiratory infirmity and other sublethal effects of saxitoxin (STX) and tetrodotoxin (TTX) can be reversed by 4-aminopyridine (4-AP) was investigated in guinea pigs chronically instrumented for the concurrent electrophysiological recordings of electrocorticogram (ECoG), diaphragmatic electromyogram (DEMG), Lead II electrocardiogram, and neck skeletal muscle electromyogram. Animals were intoxicated with either STX or TTX (2 and 3 microg/kg, im) to produce a state of progressive cardiorespiratory depression (depicted by decreasing DEMG amplitude, bradypnea, and bradycardia). At the point where cardiorespiratory performance was most seriously compromised (approximately 30 min posttoxin), 4-AP (1 or 2 mg/kg, im) was administered. The therapeutic effect of 4-AP was striking in that, within minutes, the toxin-induced diaphragmatic blockade, bradypnea, bradycardia, and depressed cortical activity were all restored to a level either comparable to, or surpassing, that of control. The optimal 4-AP dose level was determined to be 2 mg/kg (im) based on analyses of cardiorespiratory activity profiles throughout the course of intoxication and 4-AP treatment. At the dose levels (either 1 or 2 mg/kg) used to restore ventilatory function and cardiovascular performance, 4-AP produced no sign of seizures and convulsions. Although less serious secondary effects such as cortical excitant/arousal effect (indicated by ECoG power spectral analysis) and transient periods of skeletal muscle fasciculation were observed, these events were of minor concern particularly in view of the remarkable therapeutic effects of 4-AP.

4-Aminopyridine↗