Quantification of diaphragmatic EMG response to CO2 rebreathing in humans

Lopata, Melvin; Evanich, Myron J.; Lourenço, Ruy V.

doi:10.1152/jappl.1977.43.2.262

Cited by 82 publications

(46 citation statements)

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“…The stability of the EMG, despite changes in lung volume, could also be physiologically and clinically important to assess respiratory neural output using oesophageal diaphragm EMG, which was frequently used in the 1970s [4,15,19] but less so after GANDEVIA and MCKENZIE [7] suggested in 1986 that the oesophageal diaphragm EMG could not accurately reflect respiratory neural drive because of the considerable influence of lung volume on the diaphragm CMAP.…”

Section: Discussionmentioning

confidence: 99%

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Effect of lung volume on the oesophageal diaphragm EMG assessed by magnetic phrenic nerve stimulation

Luo¹,

Lyall²,

Harris³

et al. 2000

Eur Respir J

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To reassess the effect of lung volume on the oesophageal diaphragm CMAP, six normal subjects were studied using an oesophageal catheter incorporating seven electrodes (number one being proximal and seven distal) that were 1 cm in length and 1 cm apart. Electrode number three was positioned at the centre of the electrically active region of the diaphragm (EARdi) at functional residual capacity (FRC). The diaphragm CMAP elicited by bilateral magnetic stimulation of the phrenic nerves was simultaneously recorded from four electrode pairs. Pair one was created from electrodes one and three, pair two from electrodes two and four, pair three from electrodes three and five, and pair four from electrodes five and seven. Phrenic nerve stimulation was at residual volume (RV), FRC, FRC+1.0 L, FRC+2.0 L, and total lung capacity (TLC).The CMAP recorded from pair one was least influenced by changes in lung volume and the amplitude was 2.41 0.39 (mean SD), 2.60 0.27, 2.64 0.29, and 2.71 0.45 mV at RV, FRC, FRC+1.0 L and FRC+2.0 L, respectively. At TLC the CMAP was more variable. The CMAP amplitude recorded from pair two increased with increasing lung volume and at FRC+2.0 L was 3.7 times larger than that at FRC. Pair four usually recorded substantially smaller CMAPs at all lung volumes.This study shows that the diaphragm compound muscle action potential recorded from an oesophageal electrode just above the diaphragm is relatively stable over the lung volume range residual volume to functional residual capacity+2.0 L. Eur Respir J 2000; 15: 1033±1038.

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Section: Discussionmentioning

confidence: 99%

“…Animal studies have shown a good correlation between the phrenic nerve neurogram and the diaphragm EMG [3]. The integrated EMG during voluntary breathing has been used to assess neural drive in humans [4]. However, accurate assessment of neural respiratory drive requires reliable recording of the diaphragm EMG that is not influenced by changes in lung volume.…”

mentioning

confidence: 99%

Effect of lung volume on the oesophageal diaphragm EMG assessed by magnetic phrenic nerve stimulation

Luo¹,

Lyall²,

Harris³

et al. 2000

Eur Respir J

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“…The diaphragmatic electromyogram has been used as an index of neural output of the respiratory centers during periods of heightened respiratory drive (14). The reliability of this index is dependent on 1) the position of the recording electrode relative to the diaphragm (1 5), 2) the electrical conductivity of the immediate environment of the costal diaphragm (1 6), and 3) the length-tension state of the diaphragm (1 7).…”

Section: Discussionmentioning

confidence: 99%

“…The EMG signal was processed further utilizing a Service Associates 414 analog processor where it was filtered to allow passage of frequencies between 30 and 3000 Hz. The EMG was full-wave rectified and integrated through a simple R-C filter ( T = 100 ms) to obtain moving average (14). The EMG and processed signals were displayed on a Tektronix 5 1 1 1A storage oscilloscope and a Gould four-channel chart recorder (Brush 440).…”

Section: Methodsmentioning

confidence: 99%

Effect of Inspiratory Resistive Loading on Costal and Crural Diaphragm Electromyograms in Piglets

et al. 1987

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ABSTRAff. We examined the effect of inspiratory resistive loaded breathing (IRL) on the electromyographic (EMG) activity of the costal and crural diaphragm in nine anesthetized spontaneously breathing piglets (age 10-23 days, weight 2.8-4.4 kg). Bipolar wire electrodes were inserted into the anterior paratendinous costal diaphragm and the midportion of the crural diaphragm. EMG activity was quantified in arbitrary units ( Experimental evidence from adult animal studies suggests that the costal and crural portions of the diaphragm may be two separate muscles (1 -4). Specifically, differences in the mechanical actions (I), fiber composition (2), embryologic development (3), and segmental innervation (4) of the costal and crural segments have been documented. Furthermore, investigators have recently reported differential costal and crural diaphragm EMG activity during periods of heightened respiratory drive (5, 6), suggesting that the neural control of the two diaphragmatic segments may be different.The effect of loaded breathing on costal and crural EMG activity has not been evaluated within a neonatal context. Developmental changes in 1) the diaphragmatic muscle (7), 2) the mechanical properties of the respiratory system (8), and 3) the chemosensory and mechanoreflex systems (9-1 1) of mammals are known to exist. Thus, one cannot assume that the EMG activity of the costal and crural segments of the developing diaphragm, in response to heightened respiratory drive, are similar to those of the adult. We therefore examined the effect of inspiratory resistive loaded breathing on the EMG activity of the costal and crural diaphragm in the piglet. We hypothesized that the inspiratory EMG activity of the diaphragm is differentially distributed between its costal and crural components during inspiratory resistive loaded breathing. METHODSFarm bred piglets obtained from the University of Washington vivarium served as our study animal. Experiments were performed on nine piglets of postnatal age 10-23 days (weight 2.8-4.4 kg). The animals were anesthetized with an intravenous combination of chloralose (50 mg/kg) and urethane (200 mg/ kg) and studied in the supine position. Subsequent infusions of anesthesia were given if the piglet developed jaw clonus. Only anesthetized piglets with a respiratory rate of 15 to 30 breaths per minute, a Pa02 of greater than 60 torr in room air, and a PaC02 of less than 50 torr were studied.The trachea was surgically exposed and cut horizontally. A metal tube (6.35 mm OD) was inserted in the distal trachea, secured with suture, and attached to a Hans-Rudolph miniature two-way nonrebreathing valve (no. 2384). A femoral artery and vein were cannulated to monitor blood gases and give anesthesia. A Corning 168 Blood Gas Analyzer (Corning Glass Works, Medfield, MA) was utilized to determine arterial blood gas tensions and pH. Rectal temperature was continuously monitored (YSI Tele-Thermometer 43TA, Yellow-Springs Instrument Co., Yellow-Springs, OH) and maintained between 38.5-39.5' C (12) by a radi...

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“…The EMG signal was processed using a Service Associates 4 14 analog processor (Encinitas, CA), where it was filtered to allow passage of frequencies between 30 and 3000 Hz. The EMG was full-wave rectified and integrated through a Paynter filter with a 100-ms time constant to obtain moving time average EMG (19). In addition, an ECG signal was monitored and recorded on the FM tape via two wire electrodes placed in the chest wall.…”

Section: Methodsmentioning

confidence: 99%

Diaphragmatic Electromyogram Power-Spectral Analysis as a Function of Reduced End-Expiratory Lung Volume

et al. 1991

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ABSTRACT. We examined the centroid frequency (Fc) of the electromyogram power-frequency spectra from the costal (EMGco) and crural (EMGcr) diaphragms at functional residual capacity and at reduced end-expiratory lung volume (EELV) (induced by abdominal banding) in six anesthetized newborn piglets. EMGco and EMGcr were recorded from bipolar electrodes embedded in the costal and crural diaphragms respectively. A fast Fourier transformation of ECG free EMGco and EMGcr was used to compute the power-frequency spectra and calculate Diaphragmatic EMG power-frequency spectral analysis has been used to index diaphragmatic fatigue in newborns (1-3) and adults (4). Such analysis involves EMG monitoring in which the power or amplitude of the EMG signal is examined as a function of its various frequency components (5). The assignment of the label diaphragmatic fatigue rests on the observation that fatigue in limb skeletal muscle is associated with characteristic changes in the power of the EMG frequency components. These changes include I ) a rapid decrease in high-frequency power, 2) a progressive increase in low frequency power, and 3) a fall in the centroid or median frequency and high-to-low frequency ratio (6, 7). Supported by a grant from the West Penn Hospital Foundation. 61EMG power-frequency spectral analysis, however, can be affected by various changes in the environmental milieu of the muscle including alterations in ambient temperature (8), pH (9), and muscle blood flow (8) and by changes in muscle length/ configuration (10, 11). Few of these physiologic alterations have been examined with reference to the diaphragm (9, 12). No investigation has examined the effect of changes in lung volume (and, by inference, diaphragm length/configuration) on the EMG power-frequency spectrum of this muscle. Studies on appendicular muscle have demonstrated that EMG power shifts to lower frequencies with increasing muscle length (10, 1 1). In this regard, an increase in diaphragm length occurs when EELV is reduced (1 3-15). We, therefore, examined the effect that reductions in EELV have on the power-frequency spectrum of the costal and crural diaphragm of piglets. We hypothesized that a reduction in EELV would be associated with a significant decline in the EMG Fc of both the costal and crural diaphragm. MATERIALS AND METHODSFarm bred piglets, obtained from a local breeder who provided accurate times of farrowing, served as our study animals. Experiments were performed on six 1-to 3-d-old (weight 1.8 + 0.2 kg) piglets. Anesthesia was induced with halothane (1.0%) delivered in a background of 40% O2 via a securely fitting face mask. After cannulation of the femoral artery and vein, anesthesia was maintained with an i.v. combination of a-chloralose (50 mg/kg) and urethane (200 mg/kg); halothane administration was discontinued. Subsequent infusions of chloralose and urethane were given if the piglet developed jaw clonus. The trachea was surgically exposed and cut horizontally. A 3-mm inner diameter endotracheal tube with adapter was...

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Quantification of diaphragmatic EMG response to CO2 rebreathing in humans

Cited by 82 publications

References 0 publications

Effect of lung volume on the oesophageal diaphragm EMG assessed by magnetic phrenic nerve stimulation

Effect of lung volume on the oesophageal diaphragm EMG assessed by magnetic phrenic nerve stimulation

Effect of Inspiratory Resistive Loading on Costal and Crural Diaphragm Electromyograms in Piglets

Diaphragmatic Electromyogram Power-Spectral Analysis as a Function of Reduced End-Expiratory Lung Volume

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