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Results for “Diaphragmatic function”

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PubMed1993

Laparoscopic reduction of acute gastric volvulus.

The traditional surgical treatment of gastric volvulus involves upper abdominal laparotomy with gastric detorsion, fixation, and, when present, repair of associated diaphragmatic hernia. We describe a case of organoaxial gastric volvulus associated with a paraesophageal hernia in a poor risk patient, which was successfully treated with laparoscopic detorsion and percutaneous endoscopic gastropexy. This approach avoided the morbidity of a laparotomy and allowed the rapid recovery of gastric function.

Acute Disease↗

PubMed1998

[Intermediary syndrome in acute malathion poisoning].

BACKGROUND: Acute poisoning by an organophosphorus insecticide is frequently observed in Morocco. We report a case of malathion poisoning complicated by an intermediate syndrome. CASE REPORT: A 42-year-old woman was hospitalized 3 hours after ingestion of 50 g of malathion. Intubation and ventilatory assistance was required due to failing consciousness and bronchial plugging. On day 4, a neurological syndrome suggestive of the intermediary syndrome with diaphragmatic palsy made it necessary to continue ventilatory assistance to day 20. DISCUSSION: The intermediary syndrome occurs 24 to 96 hours after the acute cholinergic phase of organophosphorus poisoning. It consists of an exclusive neuromuscular involvement. The intermediate syndrome is confined to an abnormality of neuromuscular function in specific muscle groups: proximal limb muscles, neck flexors, motor cranial nerves and respiratory muscles, with difficult weaning from respiratory assistance. The intermediary syndrome is quite uncommon. The risk of respiratory failure emphasizes the need for close monitoring in an intensive care setting for at least 96 hours, depending on the intensity of the cholinergic syndrome.

Acute Disease↗

PubMed2003

Immunohistochemical distribution of surfactant apoprotein-A in congenital diaphragmatic hernia-II.

Morphometric analyses of the immunohistochemical expression of surfactant apoprotein A (SP-A) were carried out on the bronchioles of human congenital diaphragmatic hernia (CDH) neonates and then compared with those in a gestational and postnatal age-matched control group. There was no difference in SP-A expression between lung specimens of the control group and unaffected lungs in the CDH group. However, compared with both these lungs, the ipsilateral lungs of the CDH group showed a significant increase in SP-A expression, namely, the number of SP-A-positive cells per bronchiole, the number of SP-A-positive cells per unit perimeter of bronchiole, and the number of SP-A-positive cells per unit bronchiolar surface area. These results suggest that in lungs of CDH cases, especially ipsilateral lungs, there is a possible delay in the functional maturation or development of SP-A synthesis by the bronchiole, and this retardation may play a role in the postnatal respiratory insufficiency observed in CDH patients.

Analysis of Variance↗

PubMed1985

The effect of rebreathing CO2 on ventilation and diaphragmatic electromyography in newborn infants.

We tested the hypothesis of whether the reduced ventilatory response to CO2 in preterm as compared to term infants is related to primary central unresponsiveness, or to mechanical impairment of the respiratory pump. Eleven preterm (n = 19; gestational age 32 +/- 0.4 wk) and 14 term (n = 24; GA 40 +/- 0.3 wk) infants were studied. Minute integrated diaphragmatic activity EMGDi X f), and mean inspiratory diaphragmatic activity (EMGDi/TI), were used as indices of central output. After 3 min breathing 21% O2 (control), infants rebreathed from a bag containing 5% CO2 in 40% O2 for 2 to 3 minutes. We measured VE, VT, f, VT/TI. Sleep states were monitored. Preterm infants had a decreased ventilatory response to CO2 both in quiet sleep (QS) (0.0379 +/- 0.067 vs 0.505 +/- 0.032 L . (min . kg . kPa PACO2)-1; P less than 0.04) and in active sleep (AS) (0.210 +/- 0.032 vs 0.331 +/- 0.048 L . (min . kg . kPa PACO2)-1; P less than 0.04). The decrease in response primarily was a function of a lack of increase in tidal volume with CO2 in QS and a lack of increase in f in AS. Parallel to these changes there were significant correlations between the increases in EMGDi X f and VE with inhaled CO2 (r = 0.75; P less than 0.001); VT and EMGDi (r = 0.63; P less than 0.01); and between the increases in EMGDi/TI and VT/TI with inhaled CO2 (r = 0.64; P less than 0.001). The results suggest that ventilatory response to CO2 is (1) correlated highly with diaphragmatic indices of central output; (2) less in active than in quiet sleep; (3) less in preterm than in term infants. We conclude that despite their increased chest wall compliance, preterm infant respond less to CO2 because of central unresponsiveness.

Carbon Dioxide↗

PubMed2002

Angiopoietin-1 and VEGF in vascular development and angiogenesis in hypoplastic lungs.

We hypothesized that exposure of murine fetuses to environmental toxins, such as nitrofen, during early embryogenesis alters vasculogenesis. To address our hypothesis, we assessed protein levels of endothelial cell-selective angiogenic factors: angiopoietin (ANG)-1, vascular endothelial growth factor (VEGF), and mediator of VEGF signaling, VEGF receptor-2 [fetal liver kinase (Flk)-1], a transmembrane receptor tyrosine kinase. VEGF and Flk-1 proteins were lower in hypoplastic lungs from pseudoglandular to alveolar stages than in normal lungs at equivalent developmental time points significant for induction of pulmonary vasculogenesis and angiogenesis. ANG-1 protein was higher in hypoplastic lungs than in normal lungs at all the developmental stages considered in this study, i.e., pseudoglandular, canalicular, saccular, and alveolar stages. We assessed exogenous VEGF-mediated endothelial cell response on extracellular signal-regulated kinase (ERK) 1/2, also referred to as p44/42 mitogen-activated protein kinase. Hypoplastic lungs had more elevated ERK 1/2 protein than normal developing lungs. Exposure to exogenous VEGF activated ERK 1/2 in normal developing lungs but not in hypoplastic lungs. Our results suggest that in hypoplastic lungs: 1) low VEGF signifies negative effects on vasculogenesis/angiogenesis and indicates altered endothelial-mesenchymal interactions; 2) increased ANG-1 protein may be required to maintain vessel integrity and quiescence; and 3) regulation of ERK 1/2 protein is affected in hypoplastic lungs. We speculate that extensive remodeling of blood vessels in hypoplastic lungs may occur to compensate for structurally and functionally defective vasculature.

Angiopoietin-1↗

PubMed1986

[Trial of a new technic of transcutaneous diaphragmatic electrostimulation in man].

A new method of diaphragmatic pacing by transcutaneous electrical stimulation, using alternative currents with frequency and amplitude modulations, was tested in 12 subjects: 3 were normal and awake (group I); 4 were studied in acute respiratory failure while under mechanical ventilation and central apnea (group II) and 5 were studied while anaesthetized for peripheral venous surgery and breathing spontaneously (group III). Stimulation was performed either during spontaneous ventilation (groups I and II) or during short periods of respiratory depression (group III). Tidal volume was measured by pneumotachography. A positive correlation was found between stimulus intensity and inspired volume. This effect was not due to voluntary control alone, since diaphragmatic stimulation could support 24% of the theoretical minute ventilation in group II subjects and 64% in group III subjects. These preliminary results demonstrate the relative efficacy of this new method of diaphragmatic pacing using computerized alternative currents.

Adult↗

PubMed1987

Bradycardia associated with hiatal hernia and gastroesophageal reflux relieved by surgery.

A man known to have familial dysautonomia presented with a cardiac arrhythmia due to development of hiatal hernia and gastroesophageal reflux. Preoperative symptoms and assessment are described including use of power spectrum analysis of heart rate fluctuations which was consistent with enhanced parasympathetic stimulation. After surgical repair of hiatal hernia and fundoplication, bradycardia resolved, gastroesophageal reflux symptoms subsided, and the power spectrum analysis of heart rate confirmed decreased parasympathetic influence. Power spectrum analysis proved to be a useful adjunct in confirming preoperative autonomic imbalance and assessing the postoperative result. It is concluded that in individuals with disorders such as familial dysautonomia that are associated with autonomic dysfunction, cardiac arrhythmias may be a sign of esophageal pathology. Thus, cardiac evaluations should be accompanied by investigation of gastroesophageal structure and function and appropriate treatment may prevent a catastrophic arrhythmia.

Adult↗

PubMed2003

Reversed latissimus dorsi muscle flap for repair of recurrent congenital diaphragmatic hernia.

BACKGROUND/PURPOSE: Neonates with large congenital diaphragmatic hernias (CDH) require prosthetic patch closure of the defect because of the paucity of native diaphragmatic tissue. As the child grows, patch separation can occur necessitating reoperation. Use of vascularized autologous tissue may decrease the incidence of reherniation as tissue incorporation and growth may be improved. The authors report our early experience using a local muscle advancement flap with microneural anastomosis for those children in whom reherniation develops after prosthetic patch placement. METHODS: Seven patients with CDH (6 left and 1 right) whose synthetic diaphragmatic patch separated from the chest wall resulting in a clinically significant recurrent hernia were followed up with prospectively. After dissecting the ipsilateral latissimus dorsi off the chest wall and dividing the thoracodorsal neurovascular bundle (based on its lumbar blood supply), the synthetic patch was removed via an eighth intercostal incision. The muscle flap was placed into the hemithorax through the bed of the tenth rib and sutured in place over a Vicryl mesh scaffold. The thoracodorsal nerve was anastomosed to the phrenic nerve. Functional analysis of the flap was performed in 4 patients. RESULTS: Age at placement of the muscle graft ranged from 2 months to 48 months (median, 24 months). There has been no evidence of reherniation after placement of the muscle graft. Long-term outcome and functional analysis of the flap was available in 4 patients (mean, 19 months). Two infants had fluoroscopic and sonographic evidence of nonparadoxical neodiaphragmatic motion. In one of these, electromyographic evidence of function was documented with a phrenic nerve conduction velocity of 22 meters per second. The third infant showed no evidence of neodiaphragmatic motion, and the fourth infant had paradoxical motion. CONCLUSIONS: This is the first direct documentation of phrenic nerve function in an infant with CDH. An innervated reversed latissimus dorsi (RLD) flap reconstruction for recurrent CDH provides an alternative to prosthetic patch repair. This technique offers the advantages of autologous vascularized tissue with potential phrenic nerve innervation and physiologic neodiaphragmatic motion.

Female↗

PubMed1998

[Changes in respiratory mechanics after cardiac surgery].

Cardiac surgery involves a complex of factors adversely affecting the pulmonary function (PF). Among them mainly pleurotomy and hypothermic phrenic nerve injury may potentially deteriorate postoperative PF. In a prospective study of 236 patients undergoing cardiac surgery, pre-, early and late postoperative PFs were evaluated. The impact of different techniques of coronary artery bypass grafting, of pleurotomy and diaphragmatic dysfunction and the effect of COPD on the postoperative modification of PF was investigated. The analysis revealed a substantial impairment of postoperative PF especially when pleural cavity was entered, the patients had COPD history, diaphragmatic dysfunction, or multiple pulmonary complications were present. These aspects should be considered in optimizing the pre-, per- and postoperative management of cardiac patients. (Tab. 5, Fig. 6, Ref. 34.)

Cardiac Surgical Procedures↗

PubMed1993

Group cognitive-behavioral treatment of panic disorder.

The present study examined the efficacy of an 8-wk, cognitive-behavioral group treatment for panic disorder. Patients meeting DSM-III-R criteria for panic disorder with or without agoraphobia were randomly assigned to treatment (N = 34) or delayed treatment control (N = 33). The treatment consisted of: (a) education and corrective information; (b) cognitive therapy; (c) training in diaphragmatic breathing; and (d) interoceptive exposure. At posttreatment, 85% of treated Ss were panic free, compared to 30% of controls. Treated Ss also showed clinically significant improvement on indices of anxiety, agoraphobia, depression and fear of fear. Recovery, as estimated conservatively by the attainment of normal levels of functioning on each of the major clinical dimensions of the disorder (i.e. panic, anxiety and avoidance), was achieved in 64% of the treated Ss and 9% of the controls. At the 6 month follow-up, 63% of the treated patients met criteria for recovery. These findings mirror those from recently-completed trials of individually-administered cognitive-behavioral treatment, and suggest that CBT is a viable alternative to pharmacotherapy in the treatment of panic disorder.

Adult↗

PubMed1986

Potency of pancuronium at the diaphragm and the adductor pollicis muscle in humans.

The measurement of force of contraction of the adductor pollicis muscle following supramaximal stimulation of the ulnar nerve has become a standard method to assess the effect of neuromuscular blocking drugs. However, the diaphragm is regarded as resistant to these drugs, and considerable residual respiratory power might still be present after total block of adductor pollicis function. To quantify this differential effect, train-of-four stimulation was applied to the ulnar and the phrenic nerves in patients under N2O-halothane anesthesia. The force of contraction of the adductor pollicis muscle was measured with a force-displacement transducer and compared with the diaphragmatic electromyogram (EMG). Pancuronium cumulative dose-response curves for both muscles were determined in 10 ASA Class I adults. The mean dose (+/- SEM) required to depress adductor pollicis and diaphragm responses to first twitch stimulation (ED50) was 29.5 +/- 3.5 micrograms/kg and 59.5 +/- 7.0 micrograms/kg, respectively. Corresponding values for ED90 were 45 +/- 5 micrograms/kg and 95 +/- 11 micrograms/kg, respectively, indicating that the diaphragm required approximately twice as much pancuronium as the adductor pollicis block, the diaphragm was only 24 +/- 4% blocked. It is concluded that the adductor pollicis response might underestimate the degree of diaphragmatic relaxation. On the other hand, the administration of pancuronium in a dose sufficient to produce total paralysis might result in the inability to antagonize neuromuscular block in all muscles.

Adult↗

PubMed1993

Regional diaphragmatic length and EMG activity during inspiratory pressure support and CPAP in awake sheep.

We examined diaphragmatic mechanics in awake sheep during quiet breathing (QB) and the randomized application of 5, 10, and 15 cmH2O continuous positive airway pressure (CPAP), inspiratory pressure support (IPS), and equal combinations of IPS and CPAP (IPS/CPAP). We measured esophageal, gastric, and transdiaphragmatic (Pdi) pressures and regional length, shortening, and electromyogram (EMG) activity of both costal and crural diaphragmatic segments. Segmental resting length normalized to QB decreased during 15 cmH2O CPAP (costal, 19.2 +/- 3.3%; crural, 7.5 +/- 2.1%; P < 0.05) and during 15/15 cmH2O IPS/CPAP (costal 25.3 +/- 4.8%, crural 9.9 +/- 2.6%; P < 0.05). Only during 15 cmH2O IPS did costal shortening fraction increase (67% QB; P < 0.05). Compared with QB, during 15 cmH2O CPAP, end-tidal CO2 increased 6 Torr, regional EMG activity increased threefold, and Pdi increased 58%. During 15 cmH2O IPS these values decreased 3 Torr, threefold, and 44% respectively, but during IPS/CPAP they remained unchanged. Expiratory gastric pressure (Exp-Pga) reached 4.3 +/- 0.4 cmH2O at 15 cmH2O CPAP, but during IPS/CPAP Exp-Pga was less (maximum of 1.7 +/- 0.4 cmH2O) than at comparable CPAP (P < 0.05), despite the shorter diaphragmatic length. We conclude that: 1) IPS alters the actions of the diaphragm during CPAP, 2) Exp-Pga is poorly coupled to diaphragmatic end-expiratory length, and 3) both IPS and the release of Exp-Pga assist active diaphragmatic shortening.

Animals↗

PubMed2000

Development of an affordable diaphragmatic pump for cardiopulmonary bypass: an in vivo evaluation.

A new diaphragmatic pump (L-Y pump) and its drive unit were developed in our institute. The pump has a priming volume of 80 ml. The pump housing is 72 mm in diameter and 42 mm in height. Its total weight is 139 g. To assess and confirm the function and controllability of this pump, comparative studies of cardiopulmonary bypass (CPB) with L-Y pump (group A) and conventional roller pump (Group B) were performed using dogs. Both pumps provided pump flow of 90 to 100 ml/kg/min. The hemodynamics of both groups were stable and within the normal range. No leakage or thrombus formation was observed in the L-Y pump. All biochemistry data showed no significant differences between the 2 groups. This data demonstrated low plasma-free hemoglobin levels in the L-Y pump group; after 120 min of CPB, mean plasma free hemoglobin levels were 48.7 +/- 8.6 mg/dl in the roller pump group and 21.4 +/- 7.1 mg/dl in the L-Y pump group, and minimal hemolysis was indicated. In conclusion, this L-Y pump and its controller system might be useful for CPB in terms of its low hemolysis and good pump quality. This pump demonstrated easy manipulation, good controllability, and provided a sufficient pulsatile flow. This pump is suitable not only for CPB, but also as a long-term circulatory support system.

Animals↗

PubMed1985

Global and regional right ventricular function in normal infants and infants with transposition of the great arteries after Senning operation.

Echocardiographic assessment of right ventricular size, global function, and regional wall motion was performed in 29 normal infants and 19 infants with transposition of the great arteries 1 to 41 months after they underwent the Senning procedure. Sixteen of the patients with transposition of the great arteries were in clinically good condition and three had congestive heart failure. The right ventricular endocardial surface was digitized frame by frame for a complete cardiac cycle in both subxiphoid long-axis (coronal plane) and short-axis (parasagittal plane) views, and the cross-sectional area and the area change fraction (AF) were calculated. In each plane the right ventricular wall was subdivided into four anatomic regions (infundibular, free wall, diaphragmatic, and septal). With the use of a floating point center of mass model the direction and average extent of motion of the endocardium was determined for each region. In normal infants the infundibular and free wall portions of the right ventricle exhibited the greatest inward motion and the septal segments the least inward motion. Although the maximal area in both long-axis (r = .85) and short-axis (r = .85) views was highly correlated with body surface area (BSA), neither global nor regional function was significantly correlated with age or BSA. In clinically well patients after Senning procedure regional right ventricular function followed an entirely different pattern than that seen in normal infants. The endocardium of the septal segments showed the greatest inward motion in systole. In contrast to those in normal infants, maximal and minimal cross-sectional areas did not correlate significantly with BSA.(ABSTRACT TRUNCATED AT 250 WORDS)

Child, Preschool↗

PubMed1998

[Coronary artery bypass grafting in cases with poor left ventricular function].

From January 1987 through June 1992, 18 patients with poor left ventricular function (left ventricular ejection fraction [LVEF] less than 0.3) underwent elective isolated primary coronary artery bypass surgery. The mean age was 56.4 years (range, 46 to 72 years), and 15 were males and 3 were females. Mean pre-operative LVEF measured by ventriculography was 0.26 +/- 0.03 (range, 0.19 to 0.30). Sixteen patients (88.9%) had a prior myocardial infarction and 9 (50%) had a history of congestive heart failure. Complete revascularization was the goal for all patients, and the mean number of bypass grafts was 3.0 +/- 0.8 per patient. The left anterior descending coronary artery (LAD) was revascularized in all patients. There were no operative deaths. Post-operative LVEF improved significantly from 0.26 +/- 0.03 to 0.42 +/- 0.11 (p = 0.0002), and the regional left ventricular wall motion improved in the diaphragmatic and posterobasal regions (p < 0.01). The patency of the grafts was 93.9% in all, and 100% for LAD. The mean follow-up period was 77 months, and the overall actuarial survival rate was 88.9% at 10 years. During follow-up periods, two patients died of congestive heart failure (CHF), and two required three rehospitalizations because of CHF. The overall cardiac event free rate was 75.8% at 10 years. In patients with poor left ventricular function, surgical revascularization can be performed safely, but congestive heart failure sometimes occurs during follow-up periods and may be the cause of death. Therefore alternate forms of therapy such as cardiac transplantation and/or TMLR should be considered in selected patients.

Aged↗

PubMed2001

Physiological changes and clinical correlations of dyspnea in cancer outpatients.

The purposes of this cross-sectional study of 75 outpatients of a general oncology clinic were to assess the subjective and objective factors associated with dyspnea in cancer patients and to characterize factors that might contribute to respiratory muscle weakness demonstrated in a previous study. Patients with moderate to severe shortness of breath completed visual analogue scales (VAS) of shortness of breath (SOB) and anxiety; other data were acquired from pulmonary function tests, including maximum inspiratory pressure (MIP) and expiratory pressures; chest radiography; arterial blood gases; measurement of hemoglobin, serum potassium, phosphate, calcium, albumin, and magnesium; and ultrasound study of the diaphragm for thickness and excursion. The correlation coefficient between SOB VAS and anxiety VAS was 0.26 (P = 0.03). In stepwise multiple regression analyses, only the regression coefficient for anxiety remained significant at P < 0.05 in the multivariate model with SOB VAS as the dependent variable. The multivariate model using MIP (a measure of respiratory muscle strength) as the dependent variable, found significance for total diaphragmatic excursion, hemoglobin, phosphate, residual volume over total lung volume, vital capacity, percent predicted total lung capacity, oxygen saturation, and forced vital capacity. The regression coefficients for these variables were significant at P < 0.05 and the model accounted for 58% of the variance of MIP.

Adult↗

PubMed2004

Can maternal vitamin e supplementation prevent lung hypoplasia in the nitrofen-induced rat model of congenital diaphragmatic hernia?

Recent studies suggest a role for antioxidants in the prevention of pulmonary hypoplasia associated with congenital diaphragmatic hernia (CDH). We studied the effects of vitamin E in the nitrofen-rat model of CDH. After an initial fast, timed-pregnant Sprague-Dawley rats were gavage-fed nitrofen at gestational day 11 (term is 22 d). On the same day, one group was given a s.c. injection of vitamin E in alcohol; a second group was given an injection of alcohol alone. A third group received no treatment (control). Fetuses were delivered on day 21, and static pressure-volume curves were measured by immersion. Lungs were analyzed for total DNA and protein content by standard methods. A total of 203 fetuses were studied. Of 151 nitrofen-exposed fetuses, 77% had CDH; 92% of these were right-sided. CDH was present in 82% of vehicle-treated fetuses and 71% of vitamin E-treated fetuses (p=0.17). Nitrofen-exposed fetuses not only were smaller than control fetuses but also had disproportionately smaller lungs and poorer lung function, even when CDH was absent; however, lung function was worse when CDH was present. Vitamin E treatment did not improve either lung growth or function, although there was a trend toward less CDH. We have shown, for the first time, that the lung hypoplasia seen in nitrofen-exposed rat fetuses is associated with a dramatic reduction in static lung function, even when CDH is not present. Finally, our findings support the notion that lung hypoplasia in the nitrofen-rat model is independent of CDH formation.

Animals↗

PubMed2003

Electrodiagnostic evidence of phrenic nerve demyelination in Charcot-Marie-Tooth disease 1A.

OBJECTIVE: To determine whether neurophysiologic findings correlate to clinical respiratory signs or spirometric abnormalities in patients with hereditary motor and sensory neuropathy type 1 (Charcot-Marie-Tooth disease). DESIGN: A total of 11 patients with hereditary motor and sensory neuropathy type 1A, genetically identified, (age range, 10-58 yr) were included and studied by physical pulmonary examination, chest radiography, respiratory function tests, and bilateral transcutaneous phrenic nerve conduction. RESULTS: No patient complained of respiratory symptoms or revealed abnormal spirometric or maximal respiratory pressure data, despite a phrenic nerve conduction significantly slower (P < 0.0001; median conduction time, 18.6 msec; 95th percentile, 31.97 msec) than that recorded in the control group of healthy subjects (median, 6.05 msec; 95th percentile, 8.82 msec); the amplitudes of compound muscle action potentials were not statistically different from the controls. CONCLUSIONS: Our study confirms a dramatic phrenic nerve involvement in absence of clinical and laboratory evidence of diaphragmatic weakness; further studies and an adequate follow-up are necessary to discover whether the disease progress might encompass respiratory dysfunction at later stages.

Action Potentials↗