Diaphragmatic movement and spirometric volume in patients with one functioning lung.
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Adult↗
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Results for “Diaphragmatic function”
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Effect of PEEP and suction via chest drain on functional residual capacity and lung compliance after surgical repair of congenital diaphragmatic hernia: preliminary observations in 5 patients.
BACKGROUND/PURPOSE: Congenital diaphragmatic hernia (CDH) is associated with pulmonary hypoplasia that limits survival. The authors' knowledge on lung mechanics and lung volumes in these patients with hypoplastic lungs is still limited. Therefore, the authors performed measurements of functional residual capacity (FRC), compliance of the respiratory system (CRS), and tidal volume in 5 full-term infants (gestational age, 38 to 40 weeks; birth weight, 2,800 to 3,530 g) before and after surgical repair of neonatal CDH. METHODS: The authors studied the influence of different levels of positive end-expiratory pressure (PEEP) and suction via inserted ipsilateral chest tube connected to a water seal on lung volume and lung mechanics. A computerized tracer gas (SF6) washout method was used for serial measurements of FRC. Compliance of the respiratory system was determined according to insufflatory method. RESULTS: The authors found a preoperative compliance between 1.5 and 3.9 mL/kPa/kg and a preoperative FRC between 9.1 and 12.9 mL/kg indicating severe hypoplasia of the lungs in all patients. Immediately after surgical repair of CDH, compliance decreased to 85% (78% to 91%) of preoperative value, and FRC increased to 132% (110% to 150%) of preoperative value under mechanical ventilation while at 4 cm of water of PEEP and at -10 cm of water of suction via chest drain with the need of high fraction of inspired oxygen. After reduction of PEEP from 4 to 2 or 1 cm of water and lowering suction from -10 cm of water to -2 or 0 cm of water FRC decreased to 103% (80% to 122%) of preoperative value and compliance, and tidal volume improved to 135% (110% to 147%) of preoperative value resulting in increased alveolar ventilation, correction of acidosis and improvement in oxygenation. During the first days after surgery inadequate high PEEP or strong suction via chest tube drainage resulted in increase in FRC paralleled by decrease in compliance indicating overdistension of these hypoplastic lungs. CONCLUSIONS: The data show that overdistension of hypoplastic lungs in infants with CDH can be detected and excluded by repeated measurements of FRC and compliance in these critical ill infants. These data might help setting appropriate ventilator parameters, adequate suction via chest drain, and thereby improve gas exchange and outcome.
Chest Tubes↗
Effect of selective diaphragmatic paralysis on the inspiratory motor drive.
Using alpha-chloralose-anesthetized mechanically ventilated vagotomized dogs, we assessed the effects of selective diaphragmatic paralysis on the inspiratory motor drive. Diaphragmatic paralysis was accomplished by a bolus injection of vecuronium, a neuromuscular junction blocker, into the left phrenic artery of an in situ vascularly isolated and innervated left diaphragm. The inspiratory motor drive during spontaneous breathing attempts was assessed by measuring peak integrated electromyographic (EMG) activities of the left and right diaphragms and parasternal and alae nasi muscles. Respiratory timing parameters were measured from the integrated EMG signals of the diaphragm. Three groups of dogs were studied. In group 1 (n = 9), vecuronium was injected into the phrenic artery with the left diaphragmatic length adjusted at the functional residual capacity. Vecuronium injection (0.2 mg) resulted in a significant decline in left diaphragmatic tension and integrated EMG. Breathing frequency increased by 24% of the baseline value, whereas right diaphragm, parasternal, and alae nasi EMG activities rose to 136, 227, and 165% of their respective baseline values a few seconds after the vecuronium injection. In group 2 (n = 6), vecuronium injection in left phrenectomized animals did not alter the EMG activities of the inspiratory muscles (left EMG signal was abolished) nor did it alter respiratory timing. In group 3 (n = 4), the left diaphragm was placed in a flaccid position. Vecuronium injection in this group did not produce any changes in the EMG activities or respiratory timing. We conclude that selective diaphragmatic paralysis elicits a significant rise in the inspiratory motor drive. This effect is likely to be mediated through the inhibition of diaphragmatic Golgi tendon organ activity.
Animals↗
Intrathoracic tension incarceration of stomach and liver through right-sided congenital posterolateral diaphragmatic hernias.
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Functional Laterality↗
The vagus and recurrent laryngeal nerves in experimental congenital diaphragmatic hernia.
BACKGROUND: The etiology of the anatomic and functional abnormalities of the esophagus in infants surviving congenital diaphragmatic hernia (CDH) remains unclear. We showed previously that fetal rats with CDH have malformations of neural crest-derived structures. The aim of this study was to examine the anatomy of the vagus and the recurrent laryngeal nerves, both of neural crest origin, in rats with CDH. METHODS: We used the nitrofen-induced CDH fetal rat model. Nine control fetuses from four dams and nine fetuses with CDH from seven dams were included in this study. Embryos were fixed in formalin and a thoracic block from the larynx to tracheal bifurcation was serially sectioned in the horizontal plane. One in every ten sections was stained with hematoxylin and eosin. The image was digitalized using biological software (TDR-3dbase). Vagus and recurrent laryngeal nerves, trachea, esophagus and the great vessels were examined. In order to obtain the three-dimensional reconstructions, 90-120 consecutive images were used. RESULTS: In comparison with controls there were striking abnormalities of the vagus and the recurrent laryngeal nerves in fetuses with CDH: (1) absence of the left (2/9) or right (2/9) vagus nerves; (2) absence of the left (3/9) or right (3/9) recurrent laryngeal nerves; (3) marked hypoplasia of the trunk of the vagus (2/9); (4) deviations of their normal course and change of normal anatomical relationships into the mediastinum (2/9); and (5) abnormal branching of the lower portion of the vagus (1/9). CONCLUSIONS: Rat fetuses with CDH have anomalies of the vagus and recurrent laryngeal nerves that support the concept of a neural crest involvement in the origin of this malformation. 3-D reconstructions allow a detailed analysis and provide a precise insight into the real anatomy. These observations may explain esophageal motility disorders in CDH.
Animals↗
Preoperative treatment with recombinant human growth hormone prevents ischemia reperfusion-induced diaphragmatic dysfunction.
BACKGROUND: Respiratory complications continue to be a major cause of morbidity and mortality following major vascular surgery. The recent UK Small Aneurysm Trial cited preoperative respiratory function as the major predictor of outcome following elective aortic surgery. AIM: The aim of this study was to investigate the effect of aortic clamping and revascularization on diaphragmatic muscle function in a small animal model and to evaluate the role of preoperative treatment with recombinant human growth hormone (rhGH) in preventing diaphragmatic muscle dysfunction. METHODS: Male Sprague-Dawley rats (n = 18) were randomized into one of three groups: control (n = 6) underwent laparotomy only; IR (n = 6) had a laparotomy with infrarenal cross-clamping for 30 min followed by lower torso revascularization for 2 h; IR + rhGH (n = 6) were treated with rhGH (Genotropin 0.3 IU/kg/day) for 5 days before laparotomy and aortic cross-clamping for 30 min followed by lower torso revascularization for 2 h. Diaphragmatic muscle contractile function was assessed ex vivo using electrical field stimulation in a tissue bath. RESULTS: Two hours of IR injury resulted in a significant impairment in diaphragmatic twitch (Control, 242.01 + 38.45 g; IR, 108.55 + 7.15 g). This impairment was prevented by pretreatment with rhGH (rhGH, 319.14 + 30.71 g; P < 0.01). Tetanic function was also significantly impaired by ischemia reperfusion injury (control, 605 + 77.63 g; IR, 228.12 + 14.38 g). Again, pretreatment with rhGH prevented this deterioration (IR + rhGH, 704.39 + 45.69 g; P < 0.05) compared with controls. CONCLUSION: The results of this study suggest that preoperative administration of rhGH may have a role in preventing the diaphragmatic dysfunction associated with infrarenal aortic cross-clamping and revascularization.
Animals↗
Inactivity-induced remodeling of neuromuscular junctions in rat diaphragmatic muscle.
We hypothesized that inactivity-induced remodeling of neuromuscular junctions (NMJs) depends on fiber type and the match between muscle fiber and motoneuron (MN) activities. Two inactivity models were studied in rat diaphragmatic muscle: spinal hemisection at C2 (SH), where both diaphragmatic muscle fibers and phrenic MNs were inactive, and tetrodotoxin (TTX) nerve blockade, where only muscle fibers were inactive. After 2 weeks of inactivity, there was increased number of pre- and postsynaptic branches (fragmentation) of NMJs at type IIx/b fibers in both models. In addition, planar NMJ areas at type IIx/b fibers in the SH model were enlarged. In contrast, NMJs at type I and IIa fibers were unaffected in both SH and TTX models. Functionally, neuromuscular transmission in diaphragmatic muscle fibers improved in the SH model, but worsened in the TTX model, compared to controls. These results suggest that NMJ remodeling depends on the level of MN activity. The relative preservation of NMJs at type I and IIa fibers suggests a potential for recovery from diaphragmatic paralysis in the clinical setting, at least for respiratory behaviors.
Animals↗
Diaphragmatic hernia after right donor and hepatectomy: a rare donor complication of partial hepatectomy for transplantation.
BACKGROUND: Because of the critical worldwide shortage of cadaveric organ donors, transplant professionals have increasingly turned to living donors. Partial hepatectomy for adult living donor liver transplantation has been performed since the late 1990s. Most often, the complications of living donor hepatectomy have been related to the biliary tract, specifically biliary leaks. METHODS: A 54-year-old man underwent donor right hepatectomy for living donor liver transplantation. Three years after liver donation he presented with upper abdominal pain and fullness. Radiographic workup revealed a diaphragmatic hernia of the right hemithorax. RESULTS: After thoracoscopic evaluation of the right hemithorax, diaphragmatic hernia was repaired. Currently the patient remains well several months after the repair with complete resolution of abdominal pain, normal chest X-ray examination demonstrating no recurrence of diaphragmatic hernia, and normal liver functions tests. CONCLUSIONS: Multiple complications of living donor liver transplantation have been described the transplant literature. Diaphragmatic hernia is a formerly-undescribed complication of right donor hepatectomy for transplantation.
Hepatectomy↗
Diffuse cystic lung diseases: correlation between radiologic and functional status.
BACKGROUND: High-resolution CT (HRCT) scanning plays an important role in the diagnosis of diffuse cystic lung diseases (DCLDs). However, its role in the clinical evaluation of patients affected by DCLD has not yet been well-clarified. At present, pulmonary function tests are the only methods available for the evaluation of lung impairment due to these diseases, but their sensitivity and reliability are still limited. PURPOSE: The aim of this study was to correlate the quantitative score of cystic-aerial lesions obtained by a HRCT density mask (DM) software with pulmonary function data in DCLDs. METHODS: Spirometry, lung volumes, diffusion capacity, arterial blood gas (ABG) analysis, 6-min walking test (6-MWT), and HRCT with DM quantitative evaluation were performed in a cohort of 25 patients (lymphangioleiomyomatosis [LAM], 13 patients; Langerhans cells histiocytosis [LCH], 12 patients). Linear regression was used for the statistical analysis. The sum and mean of the air-trapping percentages at three different levels of DM study (ie, aortic arch, left lower lobe bronchus origin, and 2 cm from the diaphragmatic muscle), and various functional parameters and exercise performance values were matched for the analysis. RESULTS: An obstructive pattern was present in 13 patients (52%; LCH group, 8 patients; LAM group, 5 patients). A predominant restrictive pattern was detected only in three patients (12%; LCH group, two patients; LAM group, one patient). Nine patients (36%) walked < 350 m, and 14 of 23 patients (61%) had a significant decrease in arterial oxygen saturation during exercise (> 4 U). The results of DM quantitative study (sum and mean) significantly correlated with FVC (r = - 0.56; p < 0.001), FEV(1)/vital capacity (r = - 0.94; p < 0.002), midexpiratory phase of forced expiratory flow (r = - 0.84; p < 0.05), FEV(1) (r = - 0.82; p < 0.05), and diffusing capacity of the lung for carbon monoxide (r = - 0.82; p < 0.05), bronchial airway resistance (r = 0.79; p < 0.05), and distance walked on the 6-MWT (r = - 0.53; p < 0.05). No significant correlation was found with the results of ABG analysis. CONCLUSIONS: In DCLDs, HRCT scans with quantitative assessment performed by a DM software showed a very good correlation with functional parameters. Therefore, DM could be considered, in combination with a complete functional assessment, in the initial evaluation of patients affected by DCLDs. However, further studies are needed to assess its usefulness in the follow-up of these patients.
Adult↗
Transmural pressure during cardiogenic oscillations in rodent diaphragmatic lymphatic vessels.
BACKGROUND: The mechanism of initial lymphatic filling and the role of cardiogenic tissue motion in promoting lymph formation and propulsion are at present still controversial issues, in particular when considering interstitial tissues whose fluid pressure is well below atmospheric. To elucidate these aspects, the micropuncture technique was used to record interstitial (P(int)) and intralymphatic pressure (P(lymph)) simultaneously in the diaphragmatic lymphatic plexus draining the pleural cavity. METHODS AND RESULTS: The diaphragmatic lymphatic network was identified in anesthetized rabbits and rats through fluorescent dextrans injected intrapleurally. All P(lymph) and P(int) traces were pulsatile, oscillating either in-phase (33% of traces) or out-of-phase (67%) during cardiogenic swings. P(lymph) swept between -4.1 +/- 0.9 (SE) mmHg and 3.5 +/- 1.1 mmHg in rabbits, and between -5.1 +/- 1.0 mmHg and -2.7 +/- 1.1 mmHg in rats. P(int) oscillated between -0.8 +/- 0.7 mmHg and 4.9 +/- 0.7 mmHg in rabbits, and between -0.6 +/- 0.8 mmHg and 0.9 +/- 0.7 mmHg in rats. CONCLUSIONS: The data revealed a great functional complexity of the diaphragmatic lymphatic network and suggested that cardiogenic oscillations may play an important role in promoting lymph formation and propulsion from interstitial tissues with subatmospheric tissue pressure.
Animals↗
Breathing retraining: a three-year follow-up study of treatment for hyperventilation syndrome and associated functional cardiac symptoms.
This study was designed to evaluate the long-term effects of paced diaphragmatic breathing on subjects who reported functional cardiac symptoms and who also demonstrated associated signs of hyperventilation syndrome. Subjects were a representative sample composed of 10 out of the original 41 subjects who had participated three years previously in a study designed to evaluate the short-term effects of breathing retraining on functional cardiac symptoms and respiratory parameters (respiratory rate and end-tidal carbon dioxide). The results of this follow-up study indicate that breathing retraining had lasting effects on both respiratory parameters measured. Subjects evidenced significantly higher end-tidal carbon dioxide levels and lower respiratory rates when compared to pretreatment levels measured three years earlier. Subjects also continued to report a decrease in the frequency of functional cardiac symptoms when compared to pretreatment levels. We conclude that breathing retraining has lasting effects on respiratory physiology and is highly correlated with a reduction in reported functional cardiac symptoms.
Female↗
[Surgery for lung volume reduction].
OBJECTIVES: To define the place of lung volume reduction surgery (LVRS) for non-bullous emphysema, to discuss the mechanisms of postoperative functional improvement and to suggest guidelines for perioperative medical management. DATA SOURCES AND EXTRACTION: The Medline data base was searched for any article (original papers, editorials, comments, reviews) published in English, French or German, from 1980 to April 1998. The key words were: lung volume reduction surgery, emphysema, respiratory failure, anaesthesia, lung transplantation. The data have been analysed to explain the physiological mechanisms underlying the postoperative improvements and to assess the risk-benefit ratio associated with LVRS. Finally, proposals are suggested for selection criteria and perioperative medical strategies. DATA SYNTHESIS: Besides pharmacological treatment and lung transplantation, LVRS is considered as an alternative treatment for patients with end-stage pulmonary emphysema. Perioperative management includes selective lung ventilation, continuous peridural analgesia and a general anaesthetic technique that can be easily reversed. Care should be taken to detect and rapidly correct dynamic hyperinflation, pneumothorax, tube malpositioning and major air leaks. In a majority of selected patients (70-80%), resection of 20-30% of lung volume produces significant clinical and physiological improvement (dyspnoea, exercise capacity, FEV1, VO2max), as well as of the quality of life that has been attributed to greater elastic recoil, reduced respiratory workload and better diaphragmatic and right ventricular function. The most common complication is prolonged air leaks. In-hospital mortality varies widely (0-20%, with a median value at 4%), depending in part on the experience of the surgical team and on the selection criteria. Several factors may predict an unfavourable outcome: advanced age, hypercapnia, diffuse emphysema, predominant airway disease and previous thoracic surgery. CONCLUSIONS: According to the favourable preliminary results and an acceptable incidence of perioperative complications, LVRS is presently considered as a new therapeutic option for some patients with respiratory failure. Future clinical studies should be focused on appropriate selection criteria, operative techniques and long term outcome data.
Emphysema↗
Infant pulmonary function in a randomized trial of fetal tracheal occlusion for severe congenital diaphragmatic hernia.
Congenital diaphragmatic hernia (CDH) carries a high mortality risk secondary to pulmonary hypoplasia and respiratory failure. In experimental animals, fetal tracheal occlusion (TO) induces lung growth and morphologic maturation. We measured indicators of pulmonary function in 20 infants who were enrolled in a randomized trial of fetal TO as treatment for severe CDH [nine with conventional treatment (controls); 11 with TO]. We hypothesized that TO would improve lung function. At birth, the TO group had a lower mean gestational age (30.8 +/- 2.0 versus 37.4 +/- 1.0 wk; p=0.0002). All infants required assisted ventilation. Mortality did not differ between groups (64 versus 78%, TO and control, respectively; p=0.64). We measured respiratory mechanics at four study points: 1) first 24 h, 2) before CDH operative repair (5.9 +/- 2.2 d), 3) immediately after repair (7.0 +/- 2.2 d), and 4) before elective extubation (32.5 +/- 16.1 d). We calculated perioperative oxygenation index and alveolar-arterial oxygen difference to assess efficiency of pulmonary gas exchange. Data were analyzed by univariate and repeated measures techniques. Respiratory system compliance (Crs) was low. The rate of increase in Crs over the four study points was greater in the TO group than in control subjects. Crs in the TO group was significantly greater at study 2 (0.28 +/- 0.12 versus 0.17 +/- 0.04 mL.cm H2O(-1).kg(-1); p=0.02) and study 4 (0.93 +/- 0.45 versus 0.51 +/- 0.16 mL.cmH2O(-1).kg(-1); p=0.02). oxygenation index did not differ between groups, but alveolar-arterial oxygen difference was lower in the TO infants. We conclude that fetal TO for severe CDH results in modest improvements in neonatal pulmonary function that are of questionable clinical significance.
Administration, Inhalation↗
Magnetic resonance imaging of normal levator ani anatomy and function.
OBJECTIVE: To evaluate the anatomy and function of the levator ani in normal women by dynamic magnetic resonance imaging. METHODS: Twelve asymptomatic, nulliparous, premenopausal women with no previous pelvic surgery underwent a dynamic magnetic resonance imaging scan of their pelvis. The origin, orientation, thickness, and function of the two components of the levator ani were studied. RESULTS: The ileococcygeus is a thin muscle with an upward convexity. It slopes forward and medially. It is of variable thickness (mean thickness 2.9 mm, standard deviation 0.8 mm). There are apparent gaps in the muscle diaphragm and at its site of origin from the obturator fascia. The puborectalis is a thicker muscle. It is shaped like a belt encasing the pelvic organs. It is taller posteriorly than anteriorly. It is not attached to the bladder neck, but the midurethra and lower urethra lie in close proximity to it. The puborectalis moves dorsoventrally, whereas the ileococcygeus moves craniocaudally. CONCLUSION: The levator ani is not a single muscle but has two functional components that vary in thickness, origin, and function. The ileococcygeus has a mainly supportive function, whereas the puborectalis has a sphincteric function. Gaps in the diaphragmatic portion of the ileococcygeus are a normal finding. Individual components of the levator ani may be prone to different types of childbirth trauma and should therefore be assessed separately when planning rehabilitation.
Adult↗
Constipation presenting as respiratory distress.
This case report describes a 14-year-old boy presenting with a barrel-chested appearance and a complaint of shortness of breath on exertion. The patient had a long history of severe constipation with overflow incontinence. Physical examination suggested limited diaphragmatic excursion. Initial pulmonary function studies showed a restrictive pattern. Catharsis resulted in an 11-lb weight loss and normalization of pulmonary function. We speculate that the extrinsic upward pressure imposed on the diaphragm by a full bowel resulted in increased anteroposterior diameter, decreased lung height, and a reversible restrictive pattern on pulmonary function studies.
Acute Disease↗
Intravenous analgesia.
Pain and its treatment are known to have adverse effects on the organism, including deterioration in myocardial, diaphragmatic, and small bowel function. The provision of adequate intravenous analgesia, and the choice of agent, can ameliorate or exacerbate these manifestations of the stress response. The choice of agent, opioid or non-opioid, has in some respects become more difficult as more information has become available regarding the merits and adverse effects of each. Increased awareness of the frequency of hypoxemia secondary to the opioids' ability to cause an obstructive sleep apnea picture, and the cost efficiency of ketorolac through a reduction in opioid toxicity, contrast with recent studies which suggest that the gastrotoxic and nephrotoxic effects of ketorolac may occur earlier than previously suspected. The suitability of using the dissociative anesthetic agent ketamine in critically ill patients remains to be proven. Ketamine provides intense analgesia at subanesthetic doses. Its centrally mediated sympathomimetic action encourages hemodynamic stability, and it is relatively devoid of respiratory depressant activity. Increasing experience with ketamine outside the operating room has resulted in its successful use in cases of severe bronchospasm and status epilepticus.
Analgesics, Non-Narcotic↗
Endogenous peroxynitrite mediates mitochondrial dysfunction in rat diaphragm during endotoxemia.
It has been shown that nitric oxide (NO), synthesized by the inducible NO synthase (iNOS) expressed in the diaphragm during endotoxemia, participates in the development of muscular contractile failure. The aim of the present study was to investigate whether this deleterious action of NO was related to its effects on cellular oxidative pathways. Rats were inoculated with E. coli lipopolysaccharide (LPS) or sterile saline solution (controls) and studied at 3 and 6 h after inoculation. iNOS protein and activity could be detected in the rat diaphragm as early as 3 h after LPS, with a sustained steady-state concentration of 0.5 microM NO in the muscle associated with increased detection of hydrogen peroxide (H(2)O(2)). In vitro, the same NO concentration produced a marked increase in H(2)O(2) production by isolated control diaphragm mitochondria, thus reflecting a higher intramitochondrial concentration of nondiffusible superoxide anion (O(2)(-.)). In a similar way, whole diaphragmatic muscle and diaphragm mitochondria from endotoxemic rats showed a progressive increase in H(2)O(2) production associated with uncoupling and decreased phosphorylating capacity. Simultaneous with the maximal impairment in respiration (6 h after LPS), nitration of mitochondrial proteins (a peroxynitrite footprint) was detected and diaphragmatic force was reduced. Functional mitochondrial abnormalities, nitration of mitochondrial proteins, and the decrease in force were significantly attenuated by administration of the NOS inhibitor L-NMMA. These results show that increased and sustained NO levels lead to a consecutive formation of O(2)(-.) that reacts with NO to form peroxynitrite, which in turn impairs mitochondrial function, which probably contributes to the impairment of muscle contractility. during endotoxemia.
Animals↗
An intercostal-phrenic inhibitory reflex in human newborn infants.
An effect of phasic distortion of the rib cage on inspiratory time was studied in thirty sleeping newborn infants. Distortion was produced by both manual compression of various rib cage diameters, and by occluding the airway at functional residual capacity, allowing diaphragmatic contraction to alter rib cage shape. With rapid distortion produced by these maneuvers, inspiration was often terminated prematurely. The effect was dependent upon there being a rapid rate of distortion, and was most readily elicited when inward motion involved the lower lateral rib cage. The results indicate a potent inspiratory inhibitory reflex, originating most probably from the spindles of intercostal muscles. This reflex acts to decrease tidal volume and ventilation when rates of rib cage retraction are high during spontaneous breathing.
Airway Obstruction↗