Unilateral magnetic stimulation of the phrenic nerve.

Mills, Gary H.; Kyroussis, D; Hamnegärd, C H; Wragg, S; Moxham, John; Green, M

doi:10.1136/thx.50.11.1162

Cited by 91 publications

(78 citation statements)

References 16 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Although cervical magnetic stimulation has been shown to cause significant extradiaphragmatic muscle depolarization and rib cage expansion (24,25), anterolateral magnetic stimulation has been shown in adults to be a more specific stimulus (23). The shape and timing of the pressure waveforms using anterolateral magnetic stimulation in the current study were similar to the results obtained in adults (23), suggesting little coactivation of other respiratory muscles.…”

Section: Discussionsupporting

confidence: 79%

“…Strength and shape of the magnetic field and depth of penetration affect the current induced in the tissue and it is the size, waveform, and shape of the induced current that are the most important considerations in magnetic nerve stimulation. In adults, the most suitable coil for anterolateral stimulation is a 43-mm figure of eight double coil (23). The size and shape of this coil allows good positioning on the neck in adult subjects.…”

Section: Discussionmentioning

confidence: 99%

See 1 more Smart Citation

Diaphragmatic Function in Infants with Surgically Corrected Anomalies

et al. 2003

View full text Add to dashboard Cite

Infants with surgically correctable anomalies, abdominal wall defects (AWD) or congenital diaphragmatic hernia (CDH) may have poor postnatal diaphragmatic function, because the low intra-abdominal pressure experienced by such patients in utero could result in impaired diaphragmatic development. Our objective was to compare postoperative diaphragmatic function of infants with CDH or AWD to that of gestational age-matched controls. Diaphragmatic function was assessed by measurement of the transdiaphragmatic pressure and maximum inspiratory pressure at the mouth generated during crying against an occlusion. In addition, the transdiaphragmatic pressure produced by unilateral and/or bilateral magnetic stimulation of the phrenic nerves (TwPdi) was examined. Lung volume was assessed by measurement of functional residual capacity (FRC) using a helium gas dilution technique. Ten infants with CDH, 26 with AWD infants (19 gastroschisis, seven exomphalos), and 36 gestational age-matched controls were studied. Compared with their matched controls, the eight CDH infants with left-sided defects had significantly lower left (p Ͻ 0.01) and right (p Ͻ 0.05) TwPdi and FRC (p Ͻ 0.01), and the gastroschisis infants, but not those with exomphalos, had significantly lower left and right TwPdi (p Ͻ 0.05). There were no significant differences in transdiaphragmatic pressure and maximum inspiratory pressure at the mouth between the CDH or AWD infants and the controls. Surgically correctable birth defects, CDH, and AWD are common and associated with respiratory morbidity. Infants with CDH can suffer bronchopulmonary dysplasia and recurrent infections (1, 2) and, in both conditions, pulmonary function abnormalities are demonstrated outside the perinatal period (1-4). These problems may be due to poor antenatal lung growth. Abnormal diaphragmatic function impairs antenatal lung growth (5-8) and we hypothesize that infants with CDH or AWD may have abnormal diaphragmatic development and function. CDH and AWD infants experience low intraabdominal pressure in utero, as viscera are extra-abdominal. Repetitive (9) or passive (10) stretch of skeletal muscles is important to increase myofiber diameter and area. The ipsilateral diaphragm of a CDH infant would be expected to function poorly immediately after operative repair but, if our hypothesis is correct, then the contralateral diaphragm function would also be reduced because of the low intra-abdominal pressure in utero. Diaphragmatic function in neonates has previously been assessed by measurement of cPdi (11)

show abstract

Section: Discussionsupporting

confidence: 79%

Section: Discussionmentioning

confidence: 99%

Diaphragmatic Function in Infants with Surgically Corrected Anomalies

et al. 2003

View full text Add to dashboard Cite

show abstract

“…niques are now available, including unilateral magnetic stimulation (UMS) (24), bilateral anterior magnetic phrenic stimulation (23), and anterior magnetic stimulation (27,28,35). The mechanical response of the diaphragm to those stimulations is well described (15,27,36), and there have been various pathophysiological and clinical applications.…”

mentioning

confidence: 99%

Validation of improved recording site to measure phrenic conduction from surface electrodes in humans

Vérin

Straus

Demoule

et al. 2002

Journal of Applied Physiology

View full text Add to dashboard Cite

Phrenic nerve stimulation, electrical (ES) or from cervical magnetic stimulation (CMS), allows one to assess the diaphragm contractile properties and the conduction time of the phrenic nerve (PNCT) through recording of an electromyographic response, traditionally by using surface electrodes. Because of the coactivation of extradiaphragmatic muscles, signal contamination can jeopardize the determination of surface PNCTs. To address this, we compared PNCTs with ES and CMS from surface and needle diaphragm electrodes in five subjects (10 phrenic nerves). At a modified recording site, lower and more anterior than usual (lowest accessible intercostal space, costochondral junction) with electrodes 2 cm apart, surface and needle PNCTs were similar (CMS: 6.0 ± 0.25 ms surface vs. 6.2 ± 0.13 ms needle, not significant). Electrodes recording the activity of the most likely sources of signal contamination, i.e., the serratus anterior and pectoralis major, showed distinct responses from that of the diaphragm, their earlier occurrence strongly arguing against contamination. With ES and CMS, apparently uncontaminated signals could be consistently recorded from surface electrodes.

show abstract

“…Bu test burun deliği içine yerleştirilen basınç ölçerli bir kateter taşıyan bir tıkaç ve burundan havayı içe çekme sıra-sında oluşan negatif basıncın inspiratuvar kas gücü değeri olarak cmH 2 O cinsinden ölçülmesi esasına dayanır (33,34). SNIP test ağır hava yolu obstrüksi-yonu olan hastalar dışında genellikle Sniff özefagus testine yakın sonuçlar verir (34)(35)(36) dan yapılması gereklidir. Bu grup testlerin başlıcaları; "Sniff esophageal pressure (Sniff Pe)", "Sniff transdiaphragmatic pressure (Sniff Pdi)" ve "gastric pressure"dır.…”

Section: Nazal Inspiratuvar Basınç öLçümü (Snip)unclassified

“…Yoğun bakım koşullarında ya da hastanın test uyumunun iyi olmadığı durumlarda diyafragma gücü (Pdi) tek ya da iki taraflı olarak elektriksel ya da manyetik frenik sinir stimülasyonu ile ölçülebi-lir (36)(37)(38). İstemsiz abdominal (ekspiratuvar) kas gücü ölçümü, T10 vertebra seviyesinde yüzeyel manyetik stimülasyonu takiben gastrik basınçla-rın kaydı ile yapılan ölçümdür (39).…”

Section: Sniff Transdiaphragmatic Pressure (Sniff Pdi)unclassified

Solunum Kas Fi̇zyoloji̇si̇ Ve Kas Gücü Ölçümü

Ulubay¹

2017

Bulletin of Thoracic Surgery

View full text Add to dashboard Cite

Respiratory muscle strength can be assessed noninvasively by measuring the forced vital capacity (FVC), vital capacity (VC), maximal inspiratory pressure (MIP or PImax), the maximal expiratory pressure (MEP or PEmax) and maximal sniff nasal inspiratory pressure (SNIP) tests. The MIP and SNIP reflect the strength of the diaphragm and other inspiratory muscles, while the MEP reflects the strength of the expiratory muscles including abdominal muscles and other expiratory muscles. Respiratory muscle strength can also be assessed invasively by Sniff esophageal pressure (Sniff Pe), Sniff transdiaphragmatic pressure (Sniff Pdi), gastric pressure measurement methods. Common indications for measurement of the MIP, MEP, and SNIP include clinically suspected respiratory muscle weakness, lung function consistent with respiratory muscle weakness (e.g., unexplained restrictive pattern, low vital capacity), and evaluation of whether respiratory muscle weakness has improved, remained stable, or worsened. In this topic, the anatomy, physiology of respiratory muscles, and the methods for the evaluation of muscle strength by invasive and noninvasive methods will be reviewed. Keywords: Respiratory muscles, respiratory function tests, muscle weakness ÖzetSolunum kas gücü, zorlu vital kapasite (FVC), vital kapasite (VC), maksimal inspiratuvar basınç (MIP ya da PImax), maksimal ekspiratuvar basınç (MEP ya da PEmax) ve maksimal sniff nazal inspiratuvar basınç (SNIP) testleri ile invaziv olmayan şekilde ölçülebilir. MIP ve SNIP testler, diyafragma ve diğer inspiratuvar kasların gü-cünü yansıtırken, MEP karın ve diğer ekspiratuvar kasların gücünü yansıtır. Solunum kas gücü ayrıca Sniff özefageal basınç (Sniff Pe), Sniff trans diyafragmatik basınç (Sniff Pdi) ve gastrik basınç öl-çüm yöntemleriyle invaziv olarak da ölçülebilir. MIP, MEP ve SNIP ölçümleri için en sık endikasyonlar, klinik olarak solunum kas güç-süzlüğü şüphesi, solunum kas güçsüzlüğü ile uyumlu solunum fonksiyon testi bulguları (örn. açıklanamayan restriktif patern, düşük vital kapasite gibi) ve solunum kas gücünde iyileşme, kö-tüleşme, stabil seyir durumlarının değerlendirmesidir. Bu bölüm-de, solunum kaslarının anatomisi, fizyolojisi ve invaziv, noninvaziv yöntemlerle solunum kaslarının değerlendirilme yöntemleri göz-den geçirilecektir.Anahtar kelimeler: Solunum kasları, solunum fonksiyon testleri, kas güçsüzlüğü SOLUNUM KASLARININ ANATOMİSİSolunum yolları burun ile başlar ve arka arkaya birbirini takip ederek burun boşlukları, farenks, larenks, trakea ve bronşlarla devam eder. Bronşlar akciğer içinde giderek incelerek dallara ayrılır ve sonrasında solunumsal yüzeyi meydana getiren alveolleri oluşturarak sonlanır. Dinlenme durumunda inspirasyon; diyafragma, eksternal interkostal ve skalen kasların kasılmasıyla gerçekleştirilir. Sakin solunumda görev yapan bu kaslar, primer inspirasyon kasları olarak adlandırılır. Primer inspirasyon kaslarının kasılmasıyla toraks genişler ve hacmi artar (1). Üst Hava YollarıFarenks kavitesi üç kısımdan oluşur; 1. Nazofarenks: Buru...

show abstract

Unilateral magnetic stimulation of the phrenic nerve.

Cited by 91 publications

References 16 publications

Diaphragmatic Function in Infants with Surgically Corrected Anomalies

Diaphragmatic Function in Infants with Surgically Corrected Anomalies

Validation of improved recording site to measure phrenic conduction from surface electrodes in humans

Solunum Kas Fi̇zyoloji̇si̇ Ve Kas Gücü Ölçümü

Contact Info

Product

Resources

About