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At least 235 records · Page 13Linked to original sources

Diaphragmatic dysfunction in siblings with hereditary motor and sensory neuropathy (Charcot-Marie-Tooth disease).

Hereditary motor and sensory neuropathy (Charcot-Marie-Tooth disease) is characterized by chronic degeneration of peripheral nerves and roots, resulting in distal muscle atrophy, beginning in the feet and legs and later involving the hands. The association of this disease with diaphragmatic dysfunction has not been reported. We studied a patient with hereditary motor and sensory neuropathy type 1 (Charcot-Marie-Tooth disease) and type 2 diabetes mellitus who had severe diaphragmatic impairment. Some of the clinical findings are similar to the sleep apnea syndrome, which could lead to incorrect diagnosis and delay in the administration of appropriate therapy. Transdiaphragmatic pressure studies on the subject's brother, who also has Charcot-Marie-Tooth disease and type 2 diabetes mellitus, revealed subclinical impairment of diaphragmatic function. These findings suggest that phrenic nerve involvement may be part of the spectrum of polyneuropathy in Charcot-Marie-Tooth disease in association with diabetes mellitus.

Aged↗

Sleeping and breathing.

Breathing is controlled by an automatic brain-stem controller acted on by higher neural influences that stabilize breathing and compensate for neuromechanical abnormalities. Loss of this wakefulness-dependent descending influences during nonrapid eye movement (NREM) sleep results in the appearance of a hypocapnic apnea threshold, which is associated with periodic breathing when the gain of chemical feedback loops is high. In addition, loss of the descending wakefulness influence leads to loss of motor compensation that results in a rise in upper airway resistance, obstructive sleep apnea or hypoventilation in patients with kyphoskoliosis or thoracic neuromuscular disorders. REM sleep poses different problems for the respiratory control system owing to muscular atomia and suppression of chemical feedback. These changes are associated with respiratory deterioration in patients with compromised diaphragmatic function, eg, patients with chronic obstructive pulmonary disease.

Humans↗

[Global respiratory failure as the presentation form of hypothyroidism. Report of one case].

We report a 36 years male, admitted to the hospital for progressive respiratory failure. Chest X ray and CT scan were normal. On admission, a severe bradycardia and slow intellectual activity were noted. Serum thyroid function tests showed a TSH over 150 microU/ml and T3 of 75 ng/ml. Thyroid substitution therapy was associated with a progressive improvement of respiratory function. Diaphragmatic dysfunction, central hypoventilation, airway obstruction, sleep apnea and pleural effusion have been previously reported in patients with hypothyroidism. Therefore, we recommend to measure TSH in patients with unexplained respiratory failure.

Adult↗

[Diaphragmatic weakness in sepsis: the role of oxidant stress].

In sepsis contractile weakness of the diaphragm is a major cause of the onset of respiratory failure. This muscular weakness is the result of haemodynamic and metabolic disorders secondary to sepsis and also the damaging effects of inflammatory mediators, among which oxygen free radicals play a crucial role. This role is demonstrated by the protective effect of various exogenous anti-oxidants on diaphragmatic contraction. Early in the course of sepsis there is, in animal models and in man, an increased production of oxygen free radicals and nitric oxide (NO) in the diaphragm, principally within the mitochondria. The formation of peroxinitrite as the result of the action of NO on superoxide anions impairs mitochondrial respiration and consequently the energy production necessary for diaphragmatic contraction. Among the endogenous anti-oxidant systems haem oxygenase, which splits haemoglobin into bilirubin, iron and carbon monoxide, is an effective system for the protection of diaphragmatic function by limiting the damage of oxidant stress. Nevertheless a transient deficiency of local anti-oxidant defences during the early stages of sepsis, when the production of oxygen free radicals is intense, encourages the onset of contractile weakness.

Animals↗

[A case of bilateral phrenic nerve paralysis following open heart surgery].

Coronary artery bypass surgery was performed on a 58-year-old female under cold cardioplegia with topical ice slush cooling. Bilateral phrenic paralysis was observed postoperatively, in spite of prevention with a mat during aortic cross clamp, cold injury owing to ice slush was thought to be causative. Mechanical ventilatory support continued for more than two months until her complete recovery of diaphragmatic function. She complained of sleeplessness besides respiratory symptoms, and felt uneasy. Although cold injury is mostly reversible, it is stressed that we must deliberately wean from mechanical ventilatory support, turning our attention to symptoms and blood gas analysis with as much mental assistance as possible.

Coronary Artery Bypass↗

[Late postoperative hypoxemia].

Arterial hypoxaemia may be observed several days after an uncomplicated major surgical operation and may be of constant or episodic nature. Late postoperative constant hypoxaemia is mainly due to reduced pulmonary volume on account of reduced diaphragmatic function. The cause of late postoperative episodic hypoxaemia is probably opioid-induced alterations in regulation of respiration and alterations in sleep on account of pain and stress which cause intermittent hypoventilation and central and/or obstructive apnoea. The clinical significance of late postoperative hypoxaemia is not yet fully elucidated. The data available suggest, however, that it may be a contributory factor in the development of cardiac, cerebral and wound complications. The pathogenesis should, therefore, be elucidated and rational therapeutic principles against late postoperative hypoxaemia should receive higher priority.

Humans↗

Diaphragm strength in the shrinking lung syndrome of systemic lupus erythematosus.

The cause of the reduced lung volume in the 'shrinking lung' syndrome of systemic lupus erythematosus (SLE) was investigated in 12 patients with the condition. Nine patients described persistent episodes of pleuritic chest pain. Narrow section (3 mm) computed tomography of the thorax revealed no interstitial fibrosis or significant pleural disease. Assessment of diaphragmatic function using manoeuvres more reliable than the maximal occluded efforts previously used alone to assess respiratory muscle strength, showed that diaphragm strength was unequivocally normal in nine of 12 patients. In three, maximum transdiaphragmatic pressure was moderately reduced, but phrenic nerve stimulation demonstrated that this was due to incomplete activation of the diaphragm during a maximal voluntary effort, rather than to a primary abnormality of the diaphragm. Results of maximum lung recoil pressures and dynamic compliance, and analysis of the 12-s maximum voluntary ventilation, suggested a restriction in chest-wall expansion, although it was not possible to identify the underlying cause of this on the basis of our results. We conclude that the 'shrinking lung' syndrome of SLE is not explained by a primary abnormality of the diaphragm.

Adolescent↗

[Traumatic spinal cord lesion. An interdisciplinary challenge--a synopsis of the early trauma phase].

Increased morbidity and mortality in patients with spinal cord injuries present the anesthesiologist with many problems. The extent of neuronal damage is determined not only by the initial trauma, but also by subsequent activation of lipid peroxidation and lipase reactions due to local ischemia of the spinal cord. Complete transection of the spinal cord is characterized by impairment of diaphragmatic function and cardiovascular depression due to functional sympathectomy. Since hypoxemia is a common finding in high tetraplegics, immediate, careful intubation is mandatory at the trauma site. Because of rotational instability of the cervical spine, any brisk movement of the neck must be avoided. Therefore, orotracheal intubation may be performed only after sufficient stabilization of the spine in a neutral position has been guaranteed. Functional sympathectomy of the cardiovascular system is responsible for the hypotension frequently seen in high tetraplegics. Adequate volume replacement is provided based on central venous and pulmonary capillary wedge pressures. Reduced sympathetic tone causes increased sensitivity to volatile and intravenous anesthetics, so that myocardial depressants (e.g. halothane) should preferably be avoided. Opioid-induced anesthesia and nondepolarizing muscle relaxants should, therefore, be the anesthetic technique of choice.

Combined Modality Therapy↗

[Treatment of diaphragmatic paralysis in the newborn infant].

The paralysis of the diaphragm in the newborn is a rare pathological event. The "paradoxical movement" of the affected emidiaphragm can sometimes determine a important respiratory insufficiency. Medical treatment involves supplying oxygen, CPAP by means of a nasal cannula or mechanical ventilation with PEEP. Surgical plication of the affected emidiaphragm is recommended when a regular diaphragmatic function is not restored at 5-6 weeks of age and in the presence of serious respiratory insufficiency. Three cases are reported in this article which needed different therapeutical approaches.

Diaphragm↗

[Diagnostic and prognostic value of diaphragmatic electromyography and somatosensory evoked potentials in cervical spine and spinal cord injuries].

SEP contribution to diagnosis is interesting but limited to hardly examined complete syndromes in an emergency care unit. The predictive value of SEP is high if electrophysiological data are correlated the 10th. day with the clinical status. A good prognostic value is shown when the clinical posterior column and pyramidal tract dysfunctions are equal in intensity and distribution, i.e. in complete syndromes or central spinal cord syndromes or Brown-Sequard's ones. However, not any correlation exists in cases of anterior spinal cord syndromes. Dg.EMG. is an easy, atraumatic useful tool for the clinician. It must be a systematic approach of the brain stem and cervical spinal cord phrenic centers vitality that may be involved by the trauma. When a respiratory deficiency occurs, it allows the diagnosis of a "peripheral" or "neurological" etiology. Its high prognostic value for m tor diaphragmatic function (increase or decrease) must be discussed before any therapeutic decision.

Adolescent↗

Unexplained diaphragmatic paralysis: a harbinger of malignant disease?

The records of 103 male and 39 female patients with unexplained diaphragmatic paralysis were reviewed. A probable cause of the paralysis was not revealed by the initial history, physical examination, or review of plain chest roentgenograms. Paralysis occurred on the left in 82 patients (58%), on the right in 58 (41%), and bilaterally in two (1%). Initially, 64 patients (45%) had symptoms; dyspnea, cough, and chest wall pain were the most common. Long-term follow-up showed the best prognosis to be for patients with chest wall pain and cough (improvement in 82% and 78%, respectively); dyspnea improved in only 34% of patients with this complaint. Intrathoracic malignant lesions with phrenic nerve involvement were subsequently diagnosed in five patients (3.5%) and progressive neurogenic atrophy in one (0.7%). Roentgenographic follow-up showed return of normal diaphragmatic position in only 12 instances (9.2%). Patients with unexplained diaphragmatic paralysis are unlikely to have an underlying occult malignant or neurologic process, but recovery of diaphragmatic function is also unlikely and subsidence of related symptoms is variable.

Adolescent↗

Experimental emphysema.

This animal model of emphysema exhibits the same abnormalities in respiratory mechanics as those seen in human emphysema. The histologic and radiographic findings also closely resemble changes of panacinar disease. Moreover, the progressive hypoxemia preceding hypercarbia also parallels the clinical course seen in human disease. Drawbacks of this model include the long time period required to develop significant changes and the cost of maintaining the animals for such a time period. Large cystic areas were not noted in our animals and one would have to turn to another model to address the problem of giant bullous emphysema. There is no ideal animal model of pulmonary emphysema, and the usefulness of an experimental model should be judged on how well it answers the specific questions. Significant information has been obtained using various animal models of emphysema in lung transplantation, diaphragmatic function, pulmonary hemodynamics, and in several other areas. The dog appears to be a suitable model for thoracic surgical research on emphysema.

Animals↗

[Intraoperative continuous epidural block influences postoperative changes in breathing pattern and thoracoabdominal movement associated with upper abdominal surgery].

We have examined the changes in breathing pattern and thoracoabdominal movement associated with upper abdominal surgery in order to evaluate the possible influences of nociceptive input on respiration. Sixteen patients scheduled for gastrectomy were studied. Continuous epidural block was instituted prior to the induction of anesthesia and maintained throughout the surgery in 8 of 16 patients (Group 1) while it was instituted upon the peritoneal closure and maintained thereafter in the remaining 8 patients (Group 2). Breathing pattern and thoracoabdominal motion were determined before and after surgery while the patients awake by respiratory inductance plethysmography (Respisomnography, Chest MI). Breathing frequency and minute ventilation increased significantly while tidal volume was unchanged after the operation regardless of the intraoperative epidural block. Furthermore, there were identical shortening of inspiratory time and prolongation of duty ratio (inspiratory time/duration of a breath) in the two groups. Contribution of rib cage movement on tidal volume increased significantly postoperatively in all the patients. However, the changes were significantly smaller in patients receiving intraoperative epidural block. These results indicate that the causes of tachypnea and increased minute ventilation are different from the mechanism responsible for the alteration of thoracoabdominal partitioning of ventilation after upper abdominal surgery. The former may be related to the metabolic changes and, conceivably, unaffected by continuous epidural block. While the latter may be the consequence of the reflex inhibition of the diaphragmatic function that can be, at least partially, modified by continuous epidural block.

Abdomen↗

Respiratory function after repair of congenital diaphragmatic hernia.

Respiratory function studies were carried out in 22 infants who had successful repair of diaphragmatic herniae of the Bochdalek type. Thoracic gas volume was initially reduced in only 3 of these, but subsequent studies showed that improvement occurred. There were no consistent abnormalities in either dynamic compliance or mean pulmonary conductance. This is evidence that there is rapid adaptation which compensates for any alteration in the parenchymatous tissue in the lungs or abnormalities in the bronchial tree in infants soon after the repair of congenital diaphragmetic herniae. Further studies are necessary to determine the changes in these lungs with growth.

Hernia, Diaphragmatic↗

Regional lung function in unilateral diaphragmatic paralysis.

Radioactive xenon-133 was used to study the regional lung function of five patients with unilateral diaphragmatic paralysis unassociated with intrathoracic disease. All patients showed a reduction in total lung capacity to which the affected side contributed an average of 37%. There was a decrease in the amount of inhaled xenon and a lesser decrease in the amount of injected xenon reaching the lung base on the paralysed side.The distribution in the opposite lung did not differ significantly from that found in normal subjects although the proportion of inhaled xenon reaching the lung base was rather less than in the normal group. The washout of injected xenon was normal except for slight impairment at the lung base on the paralysed side in one patient and at both bases in another.

Adult↗

[The effects of high dose atropine on function of isolated diaphragmatic preparation of rats with omethoate poisoning].

OBJECTIVE: The study was designed to examine the influence of high dose atropine on respiratory muscle of rat isolated phrenic diaphragm. METHODS: Rats were divided into 2 groups: (1) a toxic group administered with 2LD(50) omethoate, SC. (2) a contrast group with 0.9% NS, SC. The function of isolated rat phrenic diaphragm was observed by MS-302 analysis instrument physiologically and pharmacologically. RESULTS: In both groups the function of isolated rat phrenic diaphragm was significantly reduced with atropine dose increasing gradually to 0.6 mg (P < 0.01). When the atropine dose amounted to 0.8 mg. The function of isolated rat phrenic diaphragm almost disappeared in the picture. When the atropine in the diaphragm was weed out, the function of isolated rat phrenic diaphragm recovered completely in 50 minutes. CONCLUSION: It is suggested that the cause of respiratory muscle paralysis may be related to high dose of atropine.

Animals↗

Patient-controlled interscalene analgesia with ropivacaine 0.2% versus patient-controlled intravenous analgesia after major shoulder surgery: effects on diaphragmatic and respiratory function.

BACKGROUND: The authors compared the effects of patient-controlled interscalene analgesia (PCIA) with ropivacaine 0.2% and patient-controlled intravenous analgesia (PCIVA) with opioids on hemidiaphragmatic excursion and respiratory function after major shoulder surgery. METHODS: Thirty-five patients scheduled for elective major shoulder surgery were prospectively randomized to receive either PCIA or PCIVA. All patients received an interscalene block before surgery. In the PCIA group, a catheter was introduced between the anterior and middle scalene muscles. Six hours after the initial block, patients received for 48 h either a continuous infusion of 0.2% ropivacaine through the interscalene catheter at a rate of 5 ml/h plus a bolus dose of 3 or 4 ml with a lockout time of 20 min (PCIA group) or a continuous intravenous infusion of nicomorphine at a rate or 0.5 mg/h plus a bolus dose of 2 or 3 mg with a lockout time of 20 min (PCIVA group). Hemidiaphragmatic excursion and respiratory function were assessed with the patient in a 45 degrees semirecumbent position the day before the operation and 20 min (in the operating room), 24 h, and 48 h after the initial block by means of ultrasonography and spirometry, respectively. Pain relief was regularly assessed, side effects were noted, and patient satisfaction was rated 6 h after the end of the study. RESULTS: Hemidiaphragmatic excursion was similar in the two groups 20 min after interscalene block. Hemidiaphragmatic excursion was increased in the PCIA group on the nonoperated side 24 and 48 h after the interscalene block (P < 0.05). Pulmonary function was similar in the two groups at each time. Pain was better controlled in the PCIA group at 12 and 24 h (P < 0.05). The incidence of nausea and vomiting were 5.5% versus 60% for the PCIA and PCIVA groups, respectively (P < 0.05). Patient satisfaction was greater in the PCIA group (P < 0.05). CONCLUSIONS: The use of PCIA or PCIVA techniques to provide analgesia after major shoulder surgery is associated with similar effects on respiratory function. In the PCIA group, hemidiaphragmatic excursion showed a significantly greater amplitude 24 and 48 h after the initial block on the nonoperated side. The PCIA technique provided better pain control, a lower incidence of side effects, and a higher degree of patient satisfaction.

Adult↗