Phrenic nerve injury following blunt trauma.
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Phrenic nerve trauma in the absence of direct injury is unusual and may present diagnostic difficulty. Diaphragmatic paralysis resulting from phrenic nerve injury may closely mimic diaphragmatic rupture. This case highlights the value of magnetic resonance imaging in establishing diaphragmatic integrity and of ultrasonographic assessment during respiratory excursion in confirming diaphragmatic paralysis. In cases of non-contact injury involving torsional injury to the neck, an index of clinical awareness may help to establish the diagnosis of phrenic nerve trauma. (+info)
Volume and time dependence of respiratory system mechanics in normal anaesthetized paralysed humans.
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The purpose of the present investigation was to assess the effect of large tidal volumes and mean lung volumes on the viscoelastic properties of the respiratory system in normal humans; and to verify if in this case the results could be satisfactorily described by a simple linear viscoelastic model of the respiratory system. Twenty-eight subjects (7 females), aged 14-28 yrs, were studied before orthopaedic surgery on the lower limbs. None were obese, or had clinical evidence of cardiopulmonary disease. The interrupter conductance and the viscoelastic constants of the respiratory system were assessed using the rapid end-inspiratory airway occlusion method during mechanical ventilation with tidal volumes up to 3 L and applied end-expiratory pressures up to 23 cmH2O. It was found that the interrupter conductance increased linearly with lung volume over a larger range than used previously; and the viscoelastic resistance and time constant did not change over the entire range of tidal volumes and end-expiratory pressures studied. In conclusion, in normal anaesthetized, paralysed subjects a simple linear viscoelastic model satisfactorily described the viscoelastic behaviour of the respiratory system over the whole range of volume studied. (+info)
Diaphragm plication following phrenic nerve injury: a comparison of paediatric and adult patients.
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BACKGROUND: A study was undertaken to evaluate whether adults differ from children in the indications and outcome of diaphragmatic plication following phrenic nerve injury. METHODS: A retrospective study was performed of 21 patients, 10 below the age of 5 and 11 older than 37 years. The indication for surgery for all the children was failure to wean from ventilatory support. The indications for surgery in the adult group were ventilator dependency (n=4) and symptomatic dyspnoea (n=7). All patients had at least one imaging study confirming diaphragmatic paralysis. The American Thoracic Society (ATS) dyspnoea scale, pulmonary function tests, and quantitative pulmonary perfusion scans were used as evaluation parameters. At surgery the diaphragm was centrally plicated. RESULTS: One child died immediately after surgery due to irreversible heart failure and two children died within 2 months of surgery from ongoing complications of their original condition. These three patients were considered as selection failures. Seven children were weaned from ventilatory support within a median of 4 days (range 2-140). Only one of four ventilated adults was successfully weaned. Seven adults who underwent surgery for chronic symptoms had a marked subjective improvement of 2-3 levels in the ATS dyspnoea scale. Pulmonary function studies in the seven symptomatic adults showed a 40% improvement above baseline. Severely asymmetrical perfusion scans reverted to a normal pattern after plication. CONCLUSIONS: Diaphragmatic plication offers a significant benefit to children with diaphragmatic paralysis and should be performed early to facilitate weaning from mechanical ventilation. While plication is of limited benefit in weaning ventilated adults, it results in significant subjective and objective lifetime improvement in non-ventilated symptomatic adults. (+info)
Common krait (Bungarus caeruleus) bite in Anuradhapura, Sri Lanka: a prospective clinical study, 1996-98.
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Common krait (Bungarus caeruleus) is the deadliest snake found commonly in the dry zone of Sri Lanka. In Anuradhapura, 210 farmers bitten by the common krait over a three year period were investigated prospectively from 1 January 1996. The sex ratio was equal, 110 (52%) patients were in the age group 10-30 years. One hundred and one (48%) patients were severely envenomed and needed mechanical ventilation from 12 hours to 29 days (mode two days). The bite occurred at night while the victims were asleep on the floor. In 99 (47%) situations killed specimens were available for identification. The cardinal symptom was abdominal pain developing within hours of the bite. Alteration in the level of consciousness was observed in 150 (71%) patients: drowsy in 91 (43%), semiconscious in 24 (11%), and deep coma in 35 (17%). Autonomic disturbances included transient hypertension, tachycardia, lacrimation, sweating, and salivation. These manifested in 139 (66%) patients with moderate to severe envenomation. One hundred and forty nine (71%) had hypokalaemia and 105 (50%) metabolic acidosis, anterograde memory loss in 84 (40%), and delayed neuropathy in 38 (22%) patients. Polyvalent antivenom had no significant benefit (t = 0.5) in reversing respiratory paralysis and preventing delayed neurological complications. Sixteen (7.6%) patients died and a submucosal haemorrhage in the stomach was seen at necropsy in three cases. Mortality could be minimised with early and free access to mechanical ventilation. (+info)
Fibrin glue for persistent pneumothorax in neonates.
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Fibrin glue was used to treat significant pneumothoraces persisting for an average of 10 days in eight newborns. Six of the eight infants had reduction or resolution of persistent air leak within 24 hours of therapy. Two infants received a second course of therapy for recurrences. Complications encountered were bradycardia requiring manual ventilation (N=2), significant hypercalcemia (N=2), diaphragmatic paralysis (N=2), pneumothorax (PTX) on the contralateral side (N=1), and localized tissue necrosis (N=1). Fibrin glue is an effective treatment for intractable PTX but has significant risks. (+info)
Respiratory motor recovery after unilateral spinal cord injury: eliminating crossed phrenic activity decreases tidal volume and increases contralateral respiratory motor output.
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By 2 months after unilateral cervical spinal cord injury (SCI), respiratory motor output resumes in the previously quiescent phrenic nerve. This activity is derived from bulbospinal pathways that cross the spinal midline caudal to the lesion (crossed phrenic pathways). To determine whether crossed phrenic pathways contribute to tidal volume in spinally injured rats, spontaneous breathing was measured in anesthetized C2 hemisected rats at 2 months after injury with an intact ipsilateral phrenic nerve, or with ipsilateral phrenicotomy performed at the time of the SCI (i.e., crossed phrenic pathways rendered ineffective) (dual injury). Ipsilateral phrenicotomy did not alter the rapid shallow eupneic breathing pattern in C2 injured rats. However, the ability to generate large inspiratory volumes after either vagotomy or during augmented breaths was impaired if crossed phrenic activity was abolished. We also investigated whether compensatory plasticity in contralateral motoneurons would be affected by eliminating crossed phrenic activity. Thus, contralateral phrenic motor output was recorded in anesthetized, vagotomized, and mechanically ventilated rats with dual injury during chemoreceptor stimulation. Hypercapnia, hypoxia, and asphyxia increased contralateral phrenic burst amplitude in the dual injury group more than in rats with SCI alone. Dual injury rats also had elevated baseline burst frequency. Together, these results demonstrate a functional role of crossed phrenic activity after SCI. Moreover, by preventing ipsilateral phrenic motor recovery in rats with unilateral SCI, segmental and supraspinal changes could be induced in contralateral respiratory motor output beyond that seen with SCI alone. (+info)
A case of severe diphtheria complicated by myocarditis and neurorespiratory paralysis is reported. The myocarditis manifested with severe conduction disturbances including left bundle-branch block and high grade second degree atrioventricular block leading to Adams-Stokes attacks. Temporary transvenous electrical pacing for.3 days was successful in the management of this complication, but positive pressure ventilation was later required for respiratory paralysis. This case illustrates the potential value of electrical pacing in diphtheritic myocarditis. Sporadic cases of diphtheria still occur and the case fatality ratio remains at 10%, much of which is related to the occurrence of myocarditis. (+info)
Long-term ventilatory support by diaphragm pacing in quadriplegia.
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Thirty-seven quadriplegic patients with respiratory paralysis were treated by electrical stimulation of the phrenic nerves to pace the diaphragm. Full-time ventilatory support by diaphragm pacing was accomplished in 13 patients. At least half-time support was achieved in 10 others. There were two deaths unrelated to pacing in these two groups. Fourteen patients could not be paced satisfactorily, and 8 of these patients died, most of them from respiratory infections. The average time the 13 patients on total ventilatory support have had bilateral diaphragm pacemakers is 26 months. The longest is 60 months. Many of these patients are out of the hospital and several are in school or working. Injury to the phrenic nerves either by the initial trauma to the cervical cord or during operation for implantation of the nerve cuff was the most significant complication. Nerve damage from prolonged electrical stimulation has not been a problem thus far. A description of the pacemaker, the technique of its implantation, and the pacing schedule are reported. (+info)